Hardware command RD and PA
8 (343) 278-60-79


8, 90, Tatishcheva Street, Yekaterinburg city
620028, Sverdlovsk region, Russia
tel./fax (343) 231-46-54(56), 278-60-79, 382-73-00(01)
e-mail: oms11@uenserv.ru, www.uenserv.ru
Founded in 1991.
Number of employees: 70 people
Production area: 1200 sq. meters
Reports and certificates: BUREAU VERITAS ISO 9001: 2008, GOST R, “FGC UES” (Federal Grid Company of Unified Energy System) OJSC 
Areas and types of activity
Development and production of equipment for transmission of signals of high-frequency protection, emergency automation and communication. Warranty repair, maintenance and training.
Manufactured produce
·      PVZU-E – universal high-frequency protection transceiver
·      AKA “KEDR” - equipment for transmission of signals / commands of relay protection and emergency automation  (transmitter Tx, receiver Rx)
·      ShE-200-AKA – control cabinet for emergency automation command transmission equipment
·      AKA “TriTON” – apparatus for arrangement of transmission of EA and RP signals/commands, data, supervisory control information.
·      Additional devices: FR – separation filter; VCh-AVR – automation unit switching on emergency high-frequency equipment; SFN – surge protector and absorber
Equipment and maintenance:
More than 6500 devices are being successfully used by energy systems of Russia, former Soviet republics and other countries.
More than 100 enterprises become clients of the company every year. The main consumers are “FGC UES” OJSC, “IDGC Holding (Interregional Distribution Grid Companies Holding)” OJSC, “RusHydro” OJSC, “Concern Rosenergoatom” OJSC , TGC, oil and gas enterprises, etc.
Geography of clients
It covers the following territories: Russia – from Kaliningrad to Petropavlovsk-Kamchatsky, from Murmansk to Grozny, CIS countries and former Soviet republics.
Dealers and service centers:
“Elektroyuzhmontazh Corporation” LLC (Ukraine, Donetsk), EKRA-SIBIR (Krasnoyarsk city)   

Equipment АКА «KEDR» and PVZU-Е today

“URALENERGOSERVICE” LLC (Yekaterinburg) has been developing and manufacturing equipment for transmission of signals of high-frequency protection and emergency automation since 1991. Currently, devices  manufactured by the company include PVZU-Е, АКА «КЕDR» and АК «TRITON».
PVZU-Е - high-frequency protection transceiver - has been manufactured since 2000.
АКА «KEDR» - equipment for transmission of signals / commands of relay protection (RP) and emergency automation (EA) - has been manufactured since 2005.  By May 2011, more than 4000 PVZU-Е devices and 2500 АКА «КЕDR» devices have been installed and successfully exploited on power facilities of the Russian Federation and the CIS in systems of Federal Grid Company (FSK), Interregional Distribution Grid Companies (MRSK), Territorial Generating Company (TGK), Unified Generating Company (OGK), INTER Russian Open Joint-Stock Company for Power Industry and Electrification “Unified Energy System” (INTER RAO EES), RUSHYDRO, ENERGOATOM and industry.
            The main principle of “URALENERGOSERVICE” LLC utilized in development and manufacture of the equipment is continuous improvement of equipment based on operation experience, using modern technologies and aiming at meeting the consumers’ requirements. 
Main operating properties of the equipment
-          does not require startup and adjustment
-          is made on the basis of  contemporary element base, equipped with self-control and diagnostic tools, has glvanic isolation of control and warning circuit
-          construction corresponds to IEC 297 standard (International Electrotechnical Commission), enables adjustment of the main electrical, time, frequency properties right on the installation site.
-          is easy to repair due to complete interchangeability of all blocks without disassembling of the equipment
Now we shall review the main properties and functions carried out by modern PVZU-Е and АКА «КЕDR» devices.

АКА «KEDR» - equipment for transmission of RP and EA signals / commands

Subject to modification and version of the equipment, it maintains transmission of signals:
- via high frequency section via HV line 35-1150 kV,
- via allocated fiber-optic communication line (AFCL),
- via low frequency section via physical communication lines or multiplex equipment.



Number of transmitted signals / commands:  32. When the double frequency code is used in the HF/LF channel the number of commands may increase up to 64.

 Configuration of equipment for arrangement of transmission of 64 commands  within a frequency band of 4 kHz

Transmission direction - AKA KEDR Тх for 32 commands (HF version) + AKA KEDR Тх for 32 commands (Digital Interface version);
Reception direction - AKA KEDR Rх for 32 commands (HF version) + AKA KEDR Rх for 32 commands (DI version);
 At the intermediate point of HF channel, signal /command transmission is maintained by digital interface (RS-422) or LF interface, in analog form;
Signal /command transmission at the intermediate point of AFCL channel is maintained by optical interface;
Telemechanics signal transmission is possible at a speed of up to 200 bauds.
Status monitoring:
- HF section failure monitoring by transmission of test frequency signal;
- equipment monitoring: from inputs of the transmitter to output  receiver relay with light indication of the current status of the equipment and logging the transmitted commands, regime/status changes in the nonvolatile memory;
-  transmission of monitoring data to the  local net of automated ICS (industrial control systems);
- access to log from the built-in control desk or PC. Every record includes information on the date and time of the  event, 1 ms increment.
- enables operation in a single HF transmission channel with devices for transmission of emergency and control signals of the following types: VChTo-М, ANKA-AVPA, AKPA-V, АКАP-V.
Technical specification:
Frequency band
16-1000 kHz
Frequency step
4 kHz
Service band
0,3÷3,4 kHz
Level of HF signal transmission (at load of 75 Ohm) within the range of:
- up to 200/ 400/ 600/ 1000 kHz 
45/ 44/ 43/ 42 dB
Level of control signal
31 dB
Receiver sensitivity level
-22 dB
Selectivity of receiver section  (HF) at the level
80 dB
Time of command transmission: in HF/LF channel / in AFCL channel,
Not exceeding
25 ms/ 12 ms
Average service life
20 years
High-frequency protection transceiverPVZU-E is intended for work with high frequency transmission channel via HV line of 35 - 1150 kV.
If an optical interface module is installed, PVZU-E maintains operation of  high frequency protection via allocated fiber-optic communication line.
PVZU-E  in transmission channel via AFCL implies:
- operation of two transceiversviaone or two AFCL in «point-to-point» scheme;
- operation of three or four transceiversvia two AFCL in ring connection.


Transmition and reception of HF protection signals together with the relay protection devices, made on the basis of:
- electromechanical relays (phase differential protection (PDP), targeted protection);
- semiconductor elements (semiconductor protection);
- digital microprocessor terminals (including: ShE 2607-2710 by Scientific & Production Enterprise EKRA; ShL 2704 by Bresler; Micom Р547 by АREVA; L 60 by GE).
Transmission channel Failure monitoring and monitoring of availability of HF signal attenuation reserve. Automatic channel check device (ACC) controls the status of transmission channel, station and  control circuits of  protection terminal, switches on the emergency and warning signal. Up to eight ACC devices can operate in one transmission channel.
Monitoring of equipment status. The receiving radio center (RRC) block enables logging data on PVZU-E operation in nonvolatile memory whenever relay protection starts up (up to 32 records) and failures are detected by the ACC device (up to 64 records) and recording information on  real time of the event.
It is possible to use a PC for reading and analysis of information on PVZU-E operation, as well as for adjustment of operation mode settings of ACC device.


Communication in intercom regime between all points of HF channel during adjustment period. Intercom operates in  2-simplex regime and does not affect HFP operation as the transceiver control signals of protection prevail.
PDP blocking angle can be changed by means of RRC block in test mode «Phase controller».
Transmission  of information on current status of the station (its operation regimes, warning / emergency alarm), transmission channel and protection terminal to the automated ICS (industrial control systems).
Quick rearrangement of station basic parameters by means of built-in control desk (or PC via RS-232 ):
- transmission frequency (with a 1 Hz step within the range of 24-1000 kHz),
- receiver adjustment frequency (with a 250 Hz step within the range of 24-1000 kHz),
- receiver sensitivity level (with a 1 mV step within the range of 12 dB),
- temporary control signal delays by power amplifier (with a 1 electrical degree step).
Selective signal level alteration in RP filter band
- noise levels in concrete units (mV) or relatively to  sensitivity level (dB),
- level of received signal in concrete units (mV) or sensitivity level reserve in relative units (dB)
- signal level of HF transmitter in concrete units (mV).

Technical specification:
Setup frequency band24-1000 kHz
Selected frequencies step0,5 kHz
HF transmitter output power at active load of 75 Ohm within frequency bands of 24-400 kHz / 401-600 kHz / 601-1000 kHz
not less than
27 W/ 20 W/ 15 W
Receiver selectivitynot worse than 50dB
Hardware susceptibility level-11 dBm
Power intakenot exceeding 70 W
Average service life20 years
Compatibility. PVZU-E device can be connected to one HF channelwith АVЗ, AVZK, PVZ, PVZU, PVZ-90М, UPZ-70, PVZK, PVZL.            
In this case, the proper operation ofall the varieties of HF protection (both DVZ and the direct one with high-frequency blocking) is maintained. 
The proper operation of the HF channel automatic check device is maintained in transmission channel with PVZU, PVZU-М, PVZ-90(М) and PVZL. Otherwise, the  PVZU-E device will regularly diagnose itself without checking the HF transmission channel. 
Despite of abundant positive opinions of equipment operation in energy systems, “URALENERGOSERVICE” LLC is never satisfied with what has already been achieved but continuously modernize the equipment and expand the service functions taking into consideration operation experience on power facilities and appearance of new developments in microelectronics.