Point of commercial accounting 6-10 kV

Relay protection device "dead" zone (URZMZ) - this is one of the first developments, in which employees of NPO "CIT" took part as part of the research group of the IPEU them. Lenin. Under the leadership of JSC SO UES, together with FSBEI of HE "NIU MEI", LLC NPF ELNAP, a high-speed relay protection was developed, allowing to eliminate short circuits in the so-called "dead zones", that is, in areas between current transformers and circuit breakers, switchgears of power facilities. Relay protection device of the “dead” zone is intended for use in three-phase networks with a rated voltage of 110-750 kV and a frequency of 50 Hz in relay protection schemes for power plants and substations. URZMZ implement the function of the selective action of relay protection, in places of non-selective operation of the protection of adjacent elements. The URZMZ consists of six transmission modules, a reception module and a command distribution module. Transmitting modules are installed directly on the buses of the primary circuits of the switchgear of all three phases (two modules per phase, installed on both sides of the protected object). Repeating module provides connection of the device with the relay protection complex at the substation. By the principle of operation, URZMZ is a differential-phase protection, with the exchange of information about the phase of the current between the semi-sets (transmitting modules) over an optical fiber. DESCRIPTION OF THE PRINCIPLE OF ACTION OF THE URZMZ: The main elements of URZMZ are: * transmitting module; * Repeat module; * command distribution module. Explanatory diagram of URZMZ presented in Figure 1. Q - switch; TA - current transformer; A1, A2 - transmitting modules (PM): 1 - measuring unit (IB); 2 - power unit (PSU); 3 - comparison unit (BS); 4 - fiber optic modem; 5 - radio transmitter; B - reappointment module: 6 - radio; 7 - power supply; 8 - unit of the electron-optical converter; 9 - fiber optic B - command distribution module: 10 - optoelectronic converter unit; 11 - power supply; 12 - relay contact multiplier. TRANSMITTER MODULE From the IB output, we obtain information on the positive or negative instantaneous value of the current (derivative of the current). This information enters the BS. In turn, from the opposite end of the “dead” zone comes a similar signal about the direction of the current after a number of signal transforms via fiber optic modems (EOC-VOLS-OEP), which also goes to the comparison unit. If the instantaneous values of the current (derivative of the current) at both ends of the protected object have different signs for a time longer than 1.0 ms and provided that the instantaneous current exceeds the predetermined setpoint, a “short circuit to dead” command is generated zone. " This signal command arrives at the radio transmitter for transmission over the air to the earth potential to the re-reception module. The power supply of the transmitting module is autonomous and is provided from the power supply unit and the power take-off transformer. CENTER MODE The re-reception module accepts possible signal-commands from all six transmitting modules of the “dead” zone via radio channels. The radio transforms the received command signals into an electrical signal, for subsequent conversion into optical form by means of an image intensifier. Next, the command signal is transmitted to the command distribution module, installed directly in the transfer module, or the control system building is transmitted via optical fiber. COMMAND DISTRIBUTION MODULE The signal command that comes from the re-reception module is converted into an electrical form, thereby triggering the contact multiplier relay. Thus, there is a closure of normally open contacts of the relay, which are connected to the relay protection devices and signal the operation of URZMZ. The presence of "dead zones" is associated with the layout of switchgears. Previously, short circuits in such “dead zones” were eliminated only by the action of the fail-safe switch devices. In this case, the time was spent on the elimination of the closures, during which the dynamic stability of the generating equipment of power plants may be disrupted, even taking into account the possibility of using emergency control automation. During the development of the URZMZ, the inventors were able to successfully solve several practical and research problems. One of them is associated with the use of radio modules and the placement of the transmitting electronic units of the URZMZ in areas of high electromagnetic radiation, which required research in the field of electromagnetic compatibility. The introduction of URZMZ is an alternative to costly measures, such as installing additional current transformers and switches, changing the layout of switchgears, building additional network elements, implemented during the construction and modernization of power facilities and aimed at maintaining the dynamic stability of generating equipment of power plants. The elements of the TsTTN (the current sensor system, the power supply system and electronic blocks) that are part of the URZMZ have successfully passed the trial operation as a part of the dead zone relay protection device at the 500 kV Nizhegorodskaya substation. After which it was decided to mass-produce RZMZ devices at the enterprises of OOO NPP EKRA. Currently, this relay protection operates at several NPPs.