Government "HF communications" during the Great Patriotic War

P. N. Voronin

Government communications play an important role in the management of the state, its Armed Forces, and in socio-political and economic life. Its foundation was laid in 1918, when the Soviet Government moved to Moscow. Initially, a manual communication switch with 25 numbers was installed in Moscow, then it was expanded and subsequently replaced with a telephone exchange.

Long-distance government communications (called “HF communications” in memoirs and works of fiction) were organized in the 1930s as operational communications for state security agencies. It ensured a certain secrecy of negotiations, and therefore the heads of the highest government bodies and the Armed Forces also became its subscribers. In May 1941, by order of the Council of People's Commissars of the USSR, this connection was defined as “Governmental HF Communication” and the corresponding “Regulation” was approved. In accordance with the accepted terminology, “HF communications” can be classified as one of secondary networks EASC and must meet additional requirements for the protection of transmitted information, reliability and survivability. However, it was not possible to fully implement these requirements before the start of the Great Patriotic War. As a means of controlling the Armed Forces in a combat situation, HF communications turned out to be unprepared.

The aggravation of the situation at the beginning of 1941 was felt by the increasing number of tasks for organizing HF communications for large formations and formations of the Red Army in the border zone. The night from June 21 to 22 found me performing one of these tasks. At approximately 4 o'clock in the morning, the technician on duty from Brest called and reported that the Germans had begun shelling the city. The evacuation has begun. What to do with the HF station equipment? Instructions were given to contact the local leadership and act on their instructions, but under all conditions to dismantle and remove the classified equipment. Then such calls came from Bialystok, Grodno and other cities along the western border. Thus began the war, which immediately posed a number of urgent tasks.

In view of the possible enemy bombing of Moscow, it was urgently necessary to move the Moscow HF station to a protected room. A room was allocated on the Kirovskaya metro platform. The station was closed to passengers. The installation was carried out in-house. The work was complicated by the fact that it was necessary to move the existing equipment without interrupting the operation of the HF station. We did not have backup equipment.

Similar work was carried out by the People's Commissariat (NK) of Communications. The telegraph equipment and intercity station were moved to protected premises. The work was headed by I. S. Ravich (at that time the head of the Central Directorate of Trunk Communications). We worked closely with him. The channels necessary for HF communication were to be received only from protected NK communication nodes.

The general unpreparedness of communications for war immediately had an impact. The entire network of the country was based on air lines, extremely susceptible to the influence of climatic conditions, and with the deployment of military operations and destruction by the enemy both through air bombing and sabotage groups. The Germans even used special bombs “with hooks” to destroy multi-wire communication lines. When falling, such a bomb caught on the wires with its hooks and exploded, destroying the entire bundle of wires at once.

There were also serious shortcomings in the construction of the long-distance communication network used. It was created according to a strictly radial principle. There were no ring communication lines or bypass directions, reserve communication centers protected from enemy bombing were not prepared, and even the entrances to Moscow of the main intercity routes were not ringed. If one of them was destroyed, it was impossible to switch the communication lines to another direction. NK Communications decided to urgently build in September 1941 a bypass ring communication line around Moscow along the Lyubertsy - Khimki - Pushkino - Chertanovo highway. In 1941, it was a ring located about 20 km from Moscow. NK Communications also carried out other work to improve the reliability of the long-distance network.

The task was set to provide HF communications with the fronts, and after the battle of Moscow - with the armies. A number of questions immediately arose and, first of all, who will build communication lines and operate them, how to provide front-line HF stations with communication equipment - compaction equipment, switches, batteries, classified communication equipment (ZAS) and other equipment adapted for work in field conditions .

The first issue was resolved quickly. The State Defense Committee (GKO) obliged the NK Communications and NK Defense to build and maintain Government Communications lines. But, as experience has shown, this was not The best decision. NK Communications had supervisors for servicing lines - one for tens of kilometers. With massive damage to air lines as a result of combat operations, air bombing and destruction by enemy sabotage groups, it was physically impossible to quickly repair the damage and ensure uninterrupted communications.

The NK defense signalmen were busy servicing the combat control lines and also could not focus their main attention on the Government communication lines. As a result, Government Communications worked unstably at some points, which led to justifiable complaints from subscribers. After each complaint, investigations began, clarification of the reasons, and mutual accusations began. Who is guilty? The matter reached the top leadership of the NKVD, NK Communications and NK Defense. A radical solution to this issue was needed.

In the Department of Government HF Communications of the NKVD, it was decided to create a line-operation service, for which purpose the formation of 10 line-operation companies, then another 35. Government communications began to work more steadily. But already during the battle of Moscow, when our troops began to advance and the headquarters of the fronts and armies moved forward, difficulties arose with the construction of communication lines.

This issue became especially acute in 1942, when the Germans approached the Volga and began to surround Stalingrad. I remember one autumn evening in 1942. The Germans were furiously rushing towards the city. The fighting took place at close approaches. The front headquarters was located in a shelter on the right bank of the Volga. Communication with the front was interrupted due to increased bombing of communication lines. Line units of the Government Communications made heroic efforts to restore the lines, but the enemy bombed, and communications were again disrupted. Bypass lines were also disrupted. At this time, I.V. Stalin needed contact with the Stalingrad Front. A.N. Poskrebyshev, Stalin’s assistant, called me and asked me what to report to him - when there would be contact. I answered - in 2 hours (in the hope that during this time the line would be restored). I contacted our unit and received a response that the bombing had intensified. He gave the command to make a “temporary job” - to lay the PTF-7 field cable along the ground. 2 hours later Poskrebyshev called again. I informed him that it would take another 40 minutes. After 40 minutes, Poskrebyshev suggested personally reporting to Stalin when there was communication. But at this time the line was restored. Stalin spoke with headquarters, and a personal report was not required. Soon, People's Commissar of Internal Affairs Beria and Deputy People's Commissar of Defense People's Commissar of Communications I. T. Peresypkin were summoned to Stalin. Stalin expressed great displeasure that there was no stable connection with Stalingrad and recalled that back in 1918 he had a reliable connection with Lenin while on the Tsaritsyn front.

It was instructed to make proposals providing for the responsibility of one body for the unconditional reliability of communications. Such proposals have been developed. The GKO Decree of January 30, 1943 was issued. Government Communications Troops were created, whose task was to ensure the construction, maintenance and military protection of Government Communications lines from the Headquarters of the Supreme High Command to the fronts and armies. Other lines running across the country to the republics, territories and regions, used for Government communications, remained in the service of NK Communications.

The Department of Government Communications Troops was created in the NKVD. It was headed by P.F. Uglovsky, who had previously been the head of communications for the border troops. The head of the line service in the Government Communications Department, K. A. Alexandrov, a major line specialist, became his deputy. At the fronts, Government Communications Departments were created, to which units of the Government Communications troops were subordinated - individual regiments, battalions, companies. It seems somewhat strange that the decision to create two divisions in the NKVD in charge of Government Communications - the Department and the Directorate of Troops. However, this was dictated by the specifics of the work of state security agencies: there were operational units and troops performing specific military tasks at the direction of operational agencies.

Similar to this structure, the NKVD had an operational body - the Government Communications Department, which was in charge of organizing communications, its development, technical equipment, station service, issues of maintaining secrecy - and troops that built communication lines, ensured their uninterrupted operation and guarded in pairs and secret ambushes in vulnerable places, excluding the possibility of connecting to eavesdropping lines, prevented possible sabotage.

The department and the Troops Directorate worked closely throughout the war, and there were no misunderstandings in their relationship. They united in 1959; the structure of Government Communications received its logical conclusion. The agencies and troops were able to comprehensively carry out tasks of organizing and ensuring communications in difficult combat conditions.

Communication was organized along “axes” and directions. The center line was drawn towards the front headquarters. As a rule, they tried to build two axial lines along different routes; a direction was laid towards the armies - one line of communication. Two chains were suspended on it: one was sealed with HF equipment, and the other, a service one, was intended for communication with service posts.

In the army areas, during the construction of communication lines, we often came into contact with the NK defense signalmen. They pulled one line, which was used for compaction, and the “middle point” was transferred to army signalmen for telegraph communication using the Baudot system. HF communications were organized at the main command post (CP), reserve (ZKP) and forward (PKP) points. When the front commander left for the troops, he was accompanied by a Government Communications officer with ZAS equipment. HF communications were organized at the location of the commander, taking into account existing army communication lines or NK communication lines.

The Government Communications troops received their baptism of fire in the battle on the Oryol-Kursk Bulge, where five fronts operated simultaneously and several dozen HF stations were deployed. The signalmen successfully completed the assigned tasks, ensuring continuous communication between Stavka and all fronts, armies and two representatives of Stavka-G. K. Zhukov and A. M. Vasilevsky, who had their own HF stations.

After the Battle of Orel-Kursk, the troops began a rapid offensive, liberating our territories from the German occupiers. The speed of advance of combined arms armies reached 10-15 km per day, and that of tank armies - up to 20-30 km. At such a pace, the troops did not have time to build permanent air lines. It was necessary to arm them with so-called cable-pole lines, which were deployed during the rapid advance of troops as temporary ones and were subsequently replaced with permanent ones if it was necessary to maintain this direction. This is how the line service was created.

Issues of technical equipment for front-line and army HF communication stations were also resolved. In Government Communications, to organize high-frequency channels, the SMT-34 type 10-40 kHz spectrum multiplexing system adopted at that time on the long-distance NK communication network was used. It was purely stationary equipment. The racks, 2.5 m high, weighed more than 400 kg. The stand could be transported in a car by placing it on its side. She couldn't stand any shaking. Often after transportation it took days to restore the installation. There were also no switches, batteries, block stations or other equipment adapted to field conditions. Everything had to be created anew.

The only base for the production of long-distance communication equipment at that time was the workshop at the Krasnaya Zarya plant in Leningrad. But by the end of 1941, Leningrad found itself under siege. Emergency measures were taken to evacuate this workshop to Ufa, where Plant No. 697 for the production of long-distance communication equipment and a research institute were created.

Thanks to the hard work of teams headed by prominent specialists A, E. Pleshakov and M. N. Vostokov, the SMT-42 equipment was created (in the 10-40 kHz spectrum), and then the SMT-44 equipment (field versions of the SMT-34 equipment; height - 60 cm, weight – 50 kg). It was convenient for quickly deploying and collapsing HF stations and could withstand shaking during transportation. NVChT equipment in the spectrum up to 10 kHz was also developed, and a fourth channel in the spectrum above 40 kHz was added to the SMT equipment; switches and ZAS equipment were created in the field. For the creation of this complex, the authors were awarded the State Prize. Government communications received a complete set of field communications equipment, which made it possible to quickly resolve issues related to the organization of HF communications.

An attempt was made to reserve wired communications with the fronts using radio communications. At that time, only the KB band could be used for radio communications. Industrially produced RAF and PAT stations were taken. But they have not found widespread use. The ZAS equipment used on radio channels placed high demands on channel quality, which was difficult to achieve on HF lines. In addition, subscribers who were warned that they were receiving radio communications often refused to speak. I remember such a case. After the end of the war, a peace conference was held in Paris. The Soviet delegation was headed by V. M. Molotov. We organized wired communications to Berlin using our own communication lines, and from Berlin to Paris the line was provided by the Americans. While we were having open conversations, the connection worked perfectly, as soon as the ZAS was turned on, the connection stopped. We also provided for radio backup using stationary radio communications equipment. But Molotov refused to speak on the radio, saying that he had to recognize the person he was talking to by his voice. With the ZAS equipment that was used, this was difficult to achieve. I had to quarrel with the Americans and achieve stable operation of wired communications.

A description of the activities of Government Communications during the Great Patriotic War will not be complete if we do not dwell on some of the most significant operations and events.

When Leningrad was blockaded by the Germans at the end of 1941, the question of HF communications with the Leningrad Front and the city became acute. NK Communications organized radio communications. We could not use this connection due to the lack of appropriate ZAS equipment. A wire line was needed. NK Communications and NK Defense decided to urgently lay the cable in the only possible direction - along the bottom of Lake Ladoga. The laying was already under enemy fire. As a result, a wired air connection was organized with Leningrad through Vologda to Tikhvin, then by cable to Vsevolozhskaya, then again by air to Leningrad. Headquarters had a stable HF connection with Leningrad throughout the war.

By the summer of 1942, the Germans had recovered from their defeat near Moscow and began an offensive in the southern direction. The Voronezh Front was created. I and a group of employees flew to Povorino, where the headquarters of the Voronezh Front was supposed to move. Soon the first deputy people's commissar of communications, A. A. Konyukhov, arrived there. We began work on installing nodes and organizing communications. The Germans bombed Povorino every day. During the bombing, we hid in a nearby ravine, and then continued our work again. But one day, returning from shelter, we saw the burning ruins of the buildings where we had placed our units. All equipment was also lost. "Claws" and a telephone were found. We climbed onto the entrance pole with the remaining wires. A. A. Konyukhov and I reported to our superiors about what had happened. But by this time the situation had changed and HF communications were deployed in the village of Otradnoye, where the front headquarters soon moved. Soon I was ordered to urgently leave for Stalingrad.

A very difficult situation developed in Stalingrad. All main lines of communication between Moscow and Stalingrad ran along the right bank of the Volga. After the Germans reached its bank above Stalingrad, in the town of Rynok, and below Stalingrad, in the Krasnoarmeysk area, the city found itself surrounded. On August 23, 1943, the Germans launched a massive raid. The whole city was burning. Signalmen of NK Communications, under the most difficult conditions, transported all the equipment of the intercity station to the left bank and installed a reserve node in the town of Kapustin Yar, with access to Astrakhan and Saratov. There were no existing communication lines left in Stalingrad. The headquarters of the Stalingrad Front was on the right bank. Communication with him could only be organized from the left bank. The Stalingrad HF station was also moved to the left bank in the town of Krasnaya Sloboda. Together with I.V. Klokov, the responsible representative of NK Communications, we gave instructions to build a line across the Volga.

First of all, they checked whether it was possible to use the existing cable crossing in the Market area. It was difficult to approach the cable box - the Germans controlled all approaches. And yet, on our bellies, we crawled up to her and checked the serviceability of the cable. It worked, but the Germans answered at the other end. It was impossible to use this cable for our purposes. There was only one way out - to lay a new cable crossing across the Volga. We didn't have a river cable. We decided to install the PTF-7 field cable, which is not suitable for working under water (it got wet after 1-2 days). We called Moscow to urgently send a river cable.

The laying had to be carried out under continuous mortar fire. Oil barges floating along the river caused great damage. Pierced by shells, they floated downstream, gradually plunging into the water, and cut our cables. Every day we had to put in more and more new bunches. The HF communications switch was installed in the dugout where the front command was located. LF communications were transmitted to this switch from the HF station located on the left bank.

Finally, the river cable arrived. The drum weighed more than a ton. No suitable boat was found. They made a special raft. At night we started laying, but the Germans spotted us and destroyed the raft with mortar fire. I had to start all over again. Finally the cable was installed. Before the freeze-up it worked reliably. Later, in addition to it, an overhead line was laid along the ice. The pillars were frozen into ice.

In February the Germans were defeated. Communications with Stalingrad began to work according to the pre-war scheme.

Great difficulties were encountered in organizing Government communications at the Tehran Conference of the three allied powers. In peacetime, the Soviet Union did not have wired communications with Tehran. It was necessary to organize it. The task was complicated by the fact that Stalin, as the Supreme Commander-in-Chief, needed communication not only with Moscow, but also with all fronts and armies.

I and a group of specialists went to Tehran two months before the meeting to study the situation, make a decision and organize the necessary work on installing an HF station and preparing communication lines. Having familiarized myself with the situation, I realized that the only line that can solve the problem is the Ashgabat-Kzyl-Aravat-Astara-Baku air line, laid along the shore of the Caspian Sea. By agreement with Iran, this line was built by the NK Communications as a bypass for communication with the Transcaucasus, since the Germans were breaking through to the Caucasus and could cut the lines going to Baku, the Transcaucasian Front, Georgia, and Armenia. It was necessary to find a way out of Tehran onto a bypass line. The Iranian communication lines available in this direction were in a disgusting state: they went through rice fields and were inaccessible for service. The poles were lopsided, the insulators on many of the poles were missing, and the wires were hanging on hooks or simply nailed to the poles.

The so-called Indo-European line of communication running through Iran has more or less been preserved. They decided to use it. At one time, it was built by the British on metal poles to connect London with India. The line was not used for its intended purpose and was operated by Iranian signalmen. It was decided to place the Soviet delegation in the building of the USSR Embassy, and it was also planned to locate a HF station there. The indicated line of communication was opened at the embassy. At the Sari and Astara points we made interchanges on our line. Now from Tehran there were two exits to Baku through Astara and to Ashgabat-Tashkent through Kzyl-Aravat (Turkmenistan). Thus, although with great difficulties, it was possible to ensure stable HF communications for the entire duration of the Tehran Conference.

The rapid advance of our troops in 1943-1945. required full tension in the work of the Government Communications bodies and troops. A characteristic feature of the strategic offensive was the continuous increase in its territory, gradually covering a strip of up to 2000 km. The depth of attacks on the enemy reached 600-700 km. Front headquarters moved up to three times in one operation, and army headquarters moved up to eight times. The closest interaction was established between the bodies and troops of the Government Communications and the signalmen of the NK Communications and NK Defense. The joint efforts were carried out to reconnaissance of the surviving permanent communication lines. The issues of joint construction and restoration of lines were carefully coordinated. During the summer-autumn operations of 1943, Government Communications troops built 4,041 km of new permanent lines, restored 5,612 km of lines, suspended 32,836 km of wires, and built 4,071 km of pole lines. Departments and troops were gaining experience; they were already capable of solving complex problems of organizing HF communications in any situation.

If we evaluate the completed tasks, we should focus on the proposed movements of the Supreme High Command Headquarters from Moscow to other cities. As you know, Headquarters was in Moscow throughout the war, and the Supreme Commander-in-Chief went to the front only once - to the Rzhev region. HF communication with him was maintained by mobile means. However, the decision to move Headquarters was made twice - in 1941 and 1944. In 1941, when the Germans came close to Moscow and there were 20-30 km left to the front line, the leadership of the General Staff turned to Stalin with a proposal to move Headquarters inland. According to the provisions on the conduct of military operations, the Supreme High Command should be located at a distance of 200-300 km from the front line. The situation required determining the point where the Headquarters could be moved.

As Marshal I. T. Peresypkin told me, Stalin came up to the map and said: “When Ivan the Terrible took Kazan, he had a headquarters in Arzamas, we will stop at this city.” With a group of specialists, I went to Arzamas and began organizing work on the installation of an HF station. A two-story house was chosen for Stalin, the first floor of which was given over to the HF station. During installation, the possibility of going to the fronts was provided, bypassing Moscow. However, only the Chief of the General Staff, Marshal B. M. Shaposhnikov, arrived in Arzamas and soon left back to Moscow. Instead of Arzamas, they began to prepare premises in Gorky to house the Headquarters and the Government. But he too was given the all clear. The work stopped and we returned to Moscow.

The second time the decision to move Headquarters was made in 1944, after the successful completion of Operation Bagration and the liberation of Minsk. Marshal I.T. Peresypkin informed me about this and suggested that I go to Minsk. We left together with K. A. Alexandrov. On the way, discussing the situation in Minsk, we came to the conclusion that it was necessary to strengthen communications between Minsk and Moscow. In this direction there was only one circuit, compacted with three-channel equipment. It was decided to suspend three more, two of them by the forces of the NK Communications and NK Defense and one by the troops of the Government Communications. Communication centers were deployed in Minsk and extensive work was carried out to build bypass lines around the city. After some time the all clear was given again. The headquarters remained in Moscow.

Attaching particular importance to the organization of Government communications with the fronts and armies, we should not forget about the work of the entire communication network with the republics, territories and regions, especially since a significant number of new HF stations were opened in the rear - at factories of the defense industries that manufacture weapons for the army, at the places of formation of reserve armies - and a number of others related to the needs of the front. The state of the national NK communications network played a major role in the successful work of Government Communications. Sometimes additional costs for NK communications were necessary. And, I must say, we met with complete understanding from the leadership of the People’s Commissariat of Communications, People’s Commissar I. T. Peresypkin, as well as his deputies I. S. Ravich and I. V. Klokov, who interacted closely with us.

On the eve of Victory Day in 1965, the Pravda newspaper wrote: “Special signal troops operated successfully on the fronts of the Patriotic War. In difficult combat conditions, signalmen of the state security agencies ensured stable closed communication between the leaders of the Party and the Government, the Headquarters of the Supreme High Command with the fronts and armies, skillfully stopped attempts by enemy saboteurs to disrupt communications."

Marshal of the Soviet Union I. S. Konev in his memoirs spoke about HF communications as follows: “In general, it must be said that this HF communications, as they say, was sent to us by God. It helped us out so much, it was so stable in the most difficult conditions that we need pay tribute to our equipment and our signalmen, who specially provided this high-frequency connection and in any situation literally followed on the heels of everyone who was supposed to use this connection during the movement."

The bodies and troops of Government Communications coped well with the tasks assigned to them, making a great contribution to the Victory over Nazi Germany.

For 12 years, he held the position of deputy chairman of the Interdepartmental Coordination Council for the creation of the country's Unified Automated Communications Network, during the Great Patriotic War, Pyotr Nikolaevich Voronin ensured communications between the Headquarters of the Supreme High Command and the headquarters of the fronts and armies. He was involved in the construction of backup nodes and communication lines in Moscow and around the capital. He took an active part in organizing communications during the days of the defense of Moscow, during the Battle of Stalingrad, lifting the siege of Leningrad, conducting the Oryol-Kursk, Berlin and other operations. Provided communications for the Supreme Commander-in-Chief during the Tehran and Potsdam Conferences. Awarded the Order of the October Revolution, Orders of the Patriotic War I and II degrees, three Orders of the Red Banner, three Orders of the Red Banner of Labor, two Orders of the Red Star, other military and labor orders and medals.

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ET9 | DZ9 | CCP-4 | CSP-9 Organization of high-frequency communications via power lines

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ECS8 parameterization and diagnostic system

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TG8 narrowband FSK modem

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NF8 LF access terminal

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DZ9 Relay protection command signal transmission device

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Communication channel is a set of devices and physical media that transmit signals. With the help of channels, signals are transmitted from one place to another, and also transferred in time (when storing information).

The most common devices included in the channel are amplifiers, antenna systems, switches and filters. The physical medium is often a pair of wires, a coaxial cable, a waveguide, or a medium in which electromagnetic waves propagate.

From the point of view of communication technology, the most important characteristics of communication channels are the distortions to which the signals transmitted through them are subjected. Distortions are distinguished between linear and nonlinear. Linear distortion consists of frequency and phase distortion and is described by the transient response or, equivalently, the complex channel gain. Nonlinear distortion are given by nonlinear dependencies indicating how the signal changes as it passes through the communication channel.

A communication channel is characterized by a set of signals that are sent at the transmitting end and signals that are received at the receiving end. In the case when the signals at the input and output of the channel are functions defined on a discrete set of argument values, the channel is called discrete. Such communication channels are used, for example, in pulsed operating modes of transmitters, in telegraphy, telemetry, and radar.

Several different channels can use the same technical communication line. In these cases (for example, in multi-channel communication lines with frequency or time division of signals), the channels are combined and separated using special switches or filters. Sometimes, on the contrary, one channel uses several technical communication lines.

High frequency communication (HF communication) is a type of communication in electrical networks that involves the use of high-voltage power lines as communication channels. An alternating current with a frequency of 50 Hz flows through the wires of power lines. The essence of organizing HF communications is that the same wires are used to transmit a signal along the line, but at a different frequency.

The frequency range of HF communication channels is from tens to hundreds of kHz. High-frequency communication is organized between two adjacent substations, which are connected by a power line with a voltage of 35 kV and higher. In order to get to the buses of the substation switchgear, and communication signals to the corresponding communication sets, high-frequency suppressors and communication capacitors are used.

The RF suppressor has a small resistance at power frequency current and a high resistance at the frequency of high-frequency communication channels. coupling capacitor- on the contrary: it has high resistance at a frequency of 50 Hz, and at the frequency of the communication channel it has low resistance. Thus, it is ensured that only current with a frequency of 50 Hz reaches the substation buses, and only high-frequency signals reach the HF communication set.

To receive and process HF communication signals, special filters, signal transceivers and sets of equipment that perform certain functions are installed at both substations between which HF communication is organized. Below we will consider which functions can be implemented using HF communications.

The most important function is the use of the HF channel in relay protection devices and automation of substation equipment. The HF communication channel is used in the protection of 110 and 220 kV lines - differential-phase protection and directional high-frequency protection. At both ends of the power line, protection kits are installed, which communicate with each other via an HF communication channel. Due to reliability, speed and selectivity, protection using an HF communication channel is used as the main one for each 110-220 kV overhead line.

The channel for transmitting signals for relay protection of power lines (PTL) is called relay protection channel. In relay protection and automation technology, three types of HF protection are most widespread:

filter directional,

remote with HF blocking,

differential-phase.

In the first two types of protection, a continuous HF blocking signal is transmitted via the HF channel during an external short circuit; in differential-phase protection, HF voltage pulses are transmitted via the relay protection channel. The duration of pulses and pauses is approximately the same and equal to half the period of the industrial frequency. During an external short circuit, transmitters located at both ends of the line operate at different half-cycles of the industrial frequency. Each receiver receives signals from both transmitters. As a result, in the event of an external short circuit, both receivers receive a continuous blocking signal.

When there is a short circuit on the protected line, the phase shift of the manipulating voltages occurs and time intervals appear when both transmitters are stopped. In this case, an intermittent current appears in the receiver, which is used to create a signal that acts to open the circuit breaker of this end of the protected line.

Typically, transmitters at both ends of the line operate on the same frequency. However, on long-distance lines, relay protection channels are sometimes installed with transmitters operating at different HF frequencies or at frequencies with a small interval (1500-1700 Hz). Working at two frequencies makes it possible to get rid of the harmful influence of signals reflected from the opposite end of the line. Relay protection channels use a special (dedicated) RF channel.

There are also devices that, using an RF communication channel, determine the location of damage to power lines. In addition, the RF communication channel can be used to transmit signals, SCADA, automatic control systems and other automated process control equipment systems. Thus, via a high-frequency communication channel it is possible to control the operating mode of substation equipment, as well as transmit control commands for switches and various functions.

Another function - function telephone communication . The HF channel can be used for operational negotiations between adjacent substations. In modern conditions this function is not relevant, since there are more convenient ways communication between facility maintenance personnel, but the HF channel can serve as a backup communication channel in the event of an emergency when there is no mobile or wired telephone connection.

Power line communication channel is a channel used to transmit signals in the range from 300 to 500 kHz. Various schemes for switching on communication channel equipment are used. Along with the phase-ground circuit (Fig. 1), which is the most common due to its efficiency, the following schemes are used: phase-phase, phase-two phases, two phases-ground, three phases-ground, phase-phase of different lines. The RF suppressor, coupling capacitor and connection filter used in these circuits are power line processing equipment for organizing RF communication channels along their wires.

Rice. 1. Block diagram of a simple communication channel along a power line between two adjacent substations: 1 - HF suppressor; 2 - coupling capacitor; 3 - connection filter; 4 - HF cable; 5 - TU device - TS; c - telemetry sensors; 7 - telemetry receivers; 8 - relay protection and/or teleautomatics devices; 9 - automatic telephone exchange; 10 - PBX subscriber; 11 - direct subscribers.

Line processing is needed to obtain a stable communication channel. The attenuation of the HF channel along the treated power lines is almost independent of the line switching scheme. If there is no processing, communication will be interrupted when the ends of the power line are disconnected or grounded. One of the most important problems of communication along power lines is the lack of frequencies caused by low transient attenuation between lines connected through substation buses.

HF channels can be used to communicate with operational teams that repair sections of damaged power lines and eliminate damage to electrical installations. For this purpose, special portable transceivers are used.

The following HF equipment is used and connected to the treated power line:

combined equipment for telemechanics, automation, relay protection and telephone communication channels;

specialized equipment for any one of the listed functions;

long-distance communication equipment connected to power lines through a connection device directly or using additional units to shift frequencies and increase the transmission level;

equipment for impulse control of lines.

Third

Second

First

Transformer protection circuit, in which there is differential and gas protection (DZ), which respond to shutdown of the transformer on both sides, and maximum current protection (MC), which should shutdown only on one side.

When drawing up a schematic diagram of relay protection in a collapsed form, the electrical connection of the trip circuits of two switches may not be detected. From the expanded diagram (Scheme 1) it follows that with such a connection (transverse chain) a false chain is inevitable. Two operational contacts are required for the protective relays (Scheme 2), acting on two switches or an isolating intermediate relay (Scheme 3).

Rice. – Transformer protection circuit: 1 – incorrect; 2.3 – correct

Undivided high and low voltage circuits transformer.

From Figure (1) it is clear that it is impossible to independently turn off one of the sides of the transformer without turning off the other.

This situation is corrected by turning on the intermediate relay KL.

Rice. – Transformer protection circuits: 1 – incorrect; 2 – correct

The protection of the generator and transformer unit at the power plant acts, as required, to disconnect the circuit breaker and the field extinguishing machine through the separating intermediate relays KL1 and KL2, but the relays are connected to different sections of the power buses, i.e. through different fuses.

The false circuit shown by the arrows was formed through the HL fuse monitoring lamp as a result of the blown fuse FU2.

Rice. – Formation of a false circuit when a fuse blows

1, 2, 3 – operational relay contacts

Circuits with power supply of secondary connection circuits with operational direct and alternating current

When the poles of the power source are well insulated from ground, a short to ground at one point in the secondary connection circuit usually does not entail harmful consequences. However, a second ground fault may cause false switching on or off, incorrect signaling, etc. Preventive measures in this case may include:

a) signaling of the first ground fault in one of the poles; b) bipolar (double-sided) separation of control circuit elements - practically not used due to complexity.

With isolated poles (Fig.), grounding at the point A with open closing contacts 1 will not yet cause false operation of the coil of the command body K, but as soon as the second insulation fault to ground appears in the branched network of the positive pole, false operation of the device is inevitable, since the contact 1 turns out to be shunted. This is why earth fault signaling is necessary in operational circuits, and above all at the poles of the power source.

Rice. – False operation of the device during the second ground fault

However, in complex circuits with a large number sequentially connected operational contacts, such an alarm may not detect the occurrence of a ground fault (Fig.).

Rice. – Ineffectiveness of insulation monitoring in complex circuits

When grounding appears between the contacts at a point A signaling is not possible.

In the practice of operating automatic installations with low-current equipment (up to 60 V), they sometimes resort to deliberate grounding of one of the poles, for example the positive one (it is more dusty and susceptible to electrolytic phenomena, i.e. it already has weakened insulation). This makes it easier to detect and eliminate an emergency source. In this case, it is recommended to connect the control circuit coil at one end to the pole that is grounded.

Everything that has been said about powering circuits using direct operating current can also be applied to operating alternating current with supply of circuits with linear voltage. In this case, the possibility of false operation (due to capacitive currents) and resonance phenomena should be taken into account. Since it is difficult to provide conditions for reliable operation in this case, auxiliary isolating intermediate transformers are sometimes used with grounding of one of the terminals on the secondary side.

As can be seen from the diagram, in this case, if the insulation to ground is damaged at point 2, fuse FU1 blows and a fault to ground at point 1 does not cause false switching on of contactor K.

Connection diagram of capacitors with isolation diodes

High frequency (HF) communications over high voltage lines have become widespread in all countries. In Ukraine, this type of communication is widely used in energy systems to transmit information of various types. High-frequency channels are used to transmit signals for relay protection of lines, tele-switching of circuit breakers, tele-signaling, tele-control, tele-regulation and tele-metering, for dispatch and administrative telephone communications, as well as for data transmission.

Communication channels via power lines are cheaper and more reliable than channels via special wire lines, since no funds are spent on the construction and operation of the communication line itself, and the reliability of the power line is much higher than the reliability of conventional wire lines. The implementation of high-frequency communications over power lines involves features that are not found in wired communications.

To connect communication equipment to the wires of power lines, special processing and connection devices are required to separate high voltage from low-current equipment and create a path for transmitting RF signals (Fig. 1).

Rice. – Connection of high-frequency communication equipment to high voltage lines

One of the main elements of the circuit for connecting communication equipment to power lines is a high-voltage coupling capacitor. The coupling capacitor, switched on at full mains voltage, must have sufficient electrical strength. To better match the input impedance of the line and the connecting device, the capacitance of the capacitor must be large enough. The coupling capacitors currently produced make it possible to have a connection capacitance on lines of any voltage class of at least 3000 pF, which makes it possible to obtain connection devices with satisfactory parameters. The coupling capacitor is connected to the connection filter, which grounds the lower plate of this capacitor for power frequency currents. For high-frequency currents, the connection filter, together with the coupling capacitor, matches the resistance of the high-frequency cable with the input resistance of the power line and forms a filter for transmitting high-frequency currents from the HF cable to the line with low losses. In most cases, a connection filter with a coupling capacitor forms a bandpass filter circuit that passes a certain frequency band.

The high-frequency current, passing through the coupling capacitor through the primary winding of the ground connection filter, induces a voltage in the secondary winding L2, which, through capacitor C1 and the connecting line, reaches the input of the communication equipment. The industrial frequency current passing through the coupling capacitor is small (tens to hundreds of milliamps), and the voltage drop across the connection filter winding does not exceed several volts. If there is a break or poor contact in the connection filter circuit, it may be under full line voltage, and therefore, for safety reasons, all work on the filter is carried out by grounding the lower plate of the capacitor with a special grounding knife.

By matching the input impedance of the RF communication equipment and the line, minimal losses of RF signal energy are achieved. Matching with an overhead line (OHL) having a resistance of 300–450 Ohms cannot always be completed completely, since with limited capacitance of the coupling capacitor, a filter with a characteristic resistance on the line side equal to the characteristic resistance of the OHL may have a narrow passband. To obtain the required bandwidth, in some cases it is necessary to allow an increased (up to 2 times) characteristic resistance of the filter on the line side, putting up with slightly higher losses due to reflection. The connection filter, installed at the coupling capacitor, is connected to the equipment with a high-frequency cable. Several high-frequency devices can be connected to one cable. To weaken the mutual influences between them, separation filters are used.

System automation channels - relay protection and tele-disconnection, which must be especially reliable, require the mandatory use of separation filters to separate other communication channels operating through general device accession.

To separate the RF signal transmission path from the high-voltage equipment of the substation, which may have low resistance for high frequencies of the communication channel, a high-frequency suppressor is included in the phase wire of the high-voltage line. The high-frequency suppressor consists of a power coil (reactor), through which the operating current of the line passes, and a tuning element connected parallel to the coil. The power coil of the interceptor with the tuning element forms a two-terminal network, which has a fairly high resistance at operating frequencies. For a power frequency current of 50 Hz, the arrester has very low resistance. Barriers are used that are designed to block one or two narrow bands (single- and two-frequency jammers) and one wide frequency band of tens and hundreds of kilohertz (broadband jammers). The latter are most widespread, despite the lower resistance in the stop band compared to single- and dual-frequency ones. These jammers make it possible to block the frequencies of several communication channels connected to the same line wire. The higher the inductance of the reactor, the easier it is to ensure high resistance of the suppressor over a wide frequency band. It is difficult to obtain a reactor with an inductance of several millihenries, since this leads to a significant increase in the size, weight and cost of the barrier. If you limit the active resistance in the blocking frequency band to 500–800 Ohms, which is sufficient for most channels, then the inductance of the power coil can be no more than 2 mH.

Interceptors are produced with inductance from 0.25 to 1.2 mH for operating currents from 100 to 2000 A. The higher the line voltage, the higher the operating current of the interdictor. For distribution networks, arresters with ratings of 100–300 A are produced, and for lines of 330 kV and above, the maximum operating current of the arrester is 2000 A.

Various schemes settings and the required range of blocked frequencies are obtained using capacitors, additional inductors and resistors available in the jammer tuning element.

Connection to the line can be done different ways. In an asymmetrical circuit, RF equipment is connected between a wire (or several wires) and the ground according to the “phase-ground” or “two-phase-ground” circuits. In symmetrical circuits, RF equipment is connected between two or more line wires (“phase-phase”, “phase-two phases”). In practice, the phase-phase scheme is used. When switching on the equipment between the wires of different lines, only the “phase - phase of different lines” scheme is used.

To organize HF channels along high voltage lines, the frequency range of 18–600 kHz is used. Distribution networks use frequencies starting from 18 kHz, on main lines 40–600 kHz. To obtain satisfactory parameters of the RF path on low frequencies Large values of the inductances of the power coils of the barriers and the capacitances of the coupling capacitors are required. Therefore, the lower frequency limit is limited by the parameters of processing and connection devices. The upper limit of the frequency range is determined by the permissible value of linear attenuation, which increases with increasing frequency.

1. HIGH FREQUENCY BACKGROUND

Barrier setup schemes. High-frequency suppressors have a high resistance to currents of the operating frequency of the channel and serve to separate the elements shunting the HF path (substations and branches), which, in the absence of suppressors, can lead to an increase in the attenuation of the path.

The high-frequency properties of the barrier are characterized by a stop band, i.e., a frequency band in which the resistance of the barrier is not less than a certain permissible value (usually 500 Ohms). As a rule, the barrier strip is determined by the permissible value of the active component of the barrier's resistance, but sometimes by the permissible value of the total resistance.

Interrupters differ in inductance values, permissible currents of power coils and tuning schemes. Single- and dual-frequency resonant or blunted tuning circuits and broadband circuits are used (using a full-section and half-section bandpass filter, as well as a half-section high-pass filter). Jammers with single- and dual-frequency tuning schemes often do not provide the opportunity to jam the desired frequency band. In these cases, barriers with broadband tuning schemes are used. Such configuration schemes are used when organizing protection and communication channels that have common connection equipment.

When current flows through the barrier coil, electrodynamic forces arise, acting along the axis of the coil, and radial forces, tending to break the coil. Axial forces are uneven along the length of the coil. Greater forces occur at the edges of the coil. Therefore, the pitch of the turns at the edge is larger.

The electrodynamic resistance of the barrier is determined by the maximum short-circuit current that it can withstand. In the KZ-500 barrier, at a current of 35 kA, axial forces of 7 tons (70 kN) arise.

Overvoltage protection of settings elements. The overvoltage wave that occurs on the overhead line hits the barrier. The wave voltage is distributed between the capacitors of the tuning element and the input impedance of the substation buses. The power coil represents a large resistance for a wave with a steep front and can be ignored when considering processes associated with overvoltages. To protect the tuning capacitors and the power coil, a spark gap is connected parallel to the power coil, limiting the voltage on the barrier elements to a value that is safe for them. According to the conditions of deionization of the spark gap, the breakdown voltage of the spark gap should be 2 times greater than the accompanying voltage, i.e., the voltage drop across the power coil from the maximum short-circuit current U resist = I short-circuit. ωL.

With a large pre-discharge time, the breakdown voltage of capacitors is significantly greater than the breakdown voltage of arresters; at low (less than 0.1 μs) the breakdown voltage of the capacitors becomes less than the breakdown voltage of the spark gap. Therefore, it is necessary to delay the increase in voltage on the capacitors until the spark gap is triggered, which is achieved by connecting an additional inductor L d in series with the capacitor (Fig. 15). After the breakdown of the spark gap, the voltage on the capacitor rises slowly and an additional spark gap connected in parallel with the capacitor protects it well.

Rice. – Circuits of high-frequency suppressors with an overvoltage protection device: a) single-frequency; b) dual frequency

2. COMMUNICATION CAPACITORS

General information. Coupling capacitors are used to connect HF communication, telemechanics and protection equipment to high voltage lines, as well as for power take-off and voltage measurement.

The resistance of a capacitor is inversely proportional to the frequency of the voltage applied to it and the capacitance of the capacitor. The reactance of the coupling capacitor for industrial frequency currents is therefore significantly greater than for the frequency of 50 - 600 kHz telemechanics and protection communication channels (1000 times or more), which makes it possible to use these capacitors to separate high and industrial frequency currents and prevent high voltage to electrical installations. Industrial frequency currents are diverted to ground through coupling capacitors, bypassing RF equipment. Coupling capacitors are designed for phase (in a network with a grounded neutral) and for line voltage (in a network with an isolated neutral).

For power take-off, special take-off capacitors are used, connected in series with the coupling capacitor.

In the names of capacitor elements, the letters indicate sequentially the nature of the application, type of filler, design; numbers – rated phase voltage and capacitance. SMR – connections, oil-filled, with expander; SMM – connections, oil-filled, in a metal casing. For different voltages, coupling capacitors are made up of individual elements connected in series. Capacitor elements SMR-55/√3-0.0044 are designed for normal operation at a voltage of 1.1 U ohm, elements SMR-133/√3-0.0186 - at 1.2 U ohm. The capacitance of capacitors for insulation classes 110, 154, 220, 440 and 500 kV is accepted with a tolerance of -5 to +10%.

3. FILTERS CONNECTIONS

General information and calculated dependencies. High-frequency equipment is connected to the capacitor not directly through a cable, but through a connection filter, which compensates for the reactance of the capacitor, matches the wave impedances of the line and the HF cable, and grounds the lower plate of the capacitor, thereby creating a path for industrial-frequency currents and ensuring the safety of work.

When the circuit of the linear winding of the filter is broken, phase voltage appears on the lower plate of the capacitor in relation to ground. Therefore, all switching in the linear winding circuit of the connection filter is carried out with the grounding blade turned on.

The OFP-4 filter (Fig. ,) is designed to operate on lines of 35, 110 and 220 kV according to the “phase-ground” circuit with a coupling capacitor of 1100 and 2200 pF and with a cable having a characteristic impedance of 100 Ohms. The filter has three frequency ranges. For each range there is a separate air transformer filled with insulating mass.

Rice. – Schematic diagram filter connection OFP-4

6. PROCESSING OF LIGHTNING CABLES, ANTENNAS

Lightning protection cables of high voltage lines can also be used as information transmission channels. The cables are isolated from the supports in order to save electricity; in case of atmospheric overvoltages, they are grounded through punched spark gaps. Steel cables have high attenuation for high-frequency signals and allow information to be transmitted only over short lines at frequencies of no more than 100 kHz. Bimetallic cables (steel cables with aluminum coating), aluminum cables (made of twisted steel-aluminum wires), single-layer cables (one layer is aluminum wires, the remaining layers are steel) make it possible to organize communication channels with low attenuation and interference levels. The interference is less than in communication channels via phase wires, and the RF processing and connection equipment is simpler and cheaper, since the currents flowing through the cables and the voltages on them are small. Bimetallic wires are more expensive than steel wires, so their use can be justified if RF channels through phase wires cannot be made. This can be on ultra-long, and sometimes on long-distance power lines.

Channels along cables can be connected according to the “cable-cable”, “cable-ground” and “two cables-ground” schemes. On AC overhead lines, the cables are swapped every 30 - 50 km to reduce the interference of industrial frequency currents in them, which introduces an additional attenuation of 0.15 Np for each crossing in the “cable-cable” schemes, without affecting the “two cables – cable” scheme. Earth". On gears direct current you can use the “cable-cable” scheme, since crossing is not necessary here.

Communication via lightning protection cables is not interrupted when grounding phase wires and does not depend on the line switching scheme.

Antenna communication is used to connect mobile HF equipment to overhead lines. The wire is hung along the overhead line wires or a section of lightning protection cable is used. This economical connection method does not require suppressors or coupling capacitors.

The FOX Series offers state-of-the-art solutions based on SDH/PDH primary network technologies, designed and tested for use in harsh environments. No other multiplexer solution provides such a wide range of specialized products - from teleprotection to Gigabit Ethernet using SDH technology and spectrum division.

ABB focuses on product upgradeability to protect your investment and offers efficient maintenance tools.

The FOX series complete communication solution consists of:

FOX505: Compact access multiplexer with throughput to STM-1.
FOX515/FOX615: Access multiplexer with up to STM-4 capacity, supporting a wide range of user interfaces for data and voice systems. Implementation of teleprotection functions and other application-specific features ensure compliance with all data access requirements in the enterprise.
FOX515H: Complements the FOX line and is designed for high-speed communications.
FOX660: Multiservice platform for data transmission systems.

All FOX515 series elements operate under FOXMAN, ABB's SNMP-based unified network management system. Its open architecture allows integration with third-party control systems, both higher and lower level. Graphical network display and point-and-click control make FOXMAN an ideal solution for TDM and Ethernet control at the access and data levels.

Universal Digital RF Communication System ETL600 R4

The ETL600 is a state-of-the-art RF communications solution for transmitting voice, data and protection commands over high voltage lines. Universal architecture of hardware and software The ETL600 system makes the choice between traditional analog and future-proof digital RF equipment pointless and obsolete. Using the same hardware components, the user can select digital or analog operating mode on site with just a few mouse clicks. In addition to ease-of-use, application flexibility and unprecedented data transfer speeds, the ETL600 system also ensures seamless compatibility with existing technology environments and integrates well into modern digital communications infrastructures.

User benefits

A cost-effective solution to the issue of organizing communications, providing reliable control and protection of the power system.
Reduce costs through a shared inventory of hardware and spare parts for analog and digital RF power line communications systems.
Flexible architecture for easy integration into both traditional and modern equipment.
Reliable transmission of protection signals
Efficient use of limited frequency resources through flexible transmission bandwidth selection.
Backup solution for selected mission-critical communications that are typically carried over broadband communications

Connection filter MCD80

MCD80 modular devices are used to connect the leads of an RF communications device such as the ABB ETL600 via a capacitive voltage transformer to high voltage lines.

The MCD80 filter provides optimal impedance matching for RF link output, frequency separation and safe isolation of 50/60 Hz mains frequency and transient overvoltages. Configurable for single- and multi-phase communications by high-pass or passband filtering. MCD80 devices comply with the latest IEC and ANSI standards.

Main advantages of MCD80 filters:

Designed to work with any type of HF communication equipment
The entire line of filters: broadband, bandpass, separation, phase-phase and phase-ground
Maximum possible choice of bandwidth (according to customer specifications in 1 kHz steps)
Possibility of connection to both coupling capacitors and voltage transformers
Wide range of connection capacitances 1500pF-20000pF
Possibility of adjustment at the installation site when changing the connection capacitance within the operating range of capacitances (for example, when replacing capacitors with voltage transformers)
Low insertion loss in passband (less than 1dB)
It is possible to parallel connect to one PF up to 9 terminals with a power of 80 W in a phase-to-ground circuit and up to 10 terminals in a phase-to-phase circuit
Built-in single-pole disconnector (earthing switch)

HF suppressors for overhead lines-DLTC

To protect RF suppressors, two types of DLTC surge suppressors are available.

Small and medium-sized HF suppressors are equipped with standard ABB Polim-D surge suppressors without arc arresters.

Large interceptors are equipped with ABB MVT arresters, which do not have an arc gap and are specifically designed for use with ABB interceptors. They use the same highly nonlinear metal oxide varistors (MO resistors) as station limiters.

When designing the tuning unit, the internal leakage of the MO limiter is taken into account. ABB's metal oxide surge suppressors are specifically designed for use in high electromagnetic fields, which are often present in RF power line suppressors. In particular, they do not contain unnecessary metal parts in which the magnetic field could induce eddy currents and cause an unacceptable increase in temperature. Modification of the metal oxide surge arresters for the operating conditions in power line arresters was necessary since ABB manufactures such devices for stations and is fully aware of the problems that arise in practice. Surge suppressors used in power line arresters have a rated current of 10 kA.