RS 80 «RZA SYSTEMS» — Increasing reliability and quality at a reduced price!
All power engineers are well aware of the trouble and sometimes the tragedy that occurs in any facility (substation, power plant) when operating current is lost — the substation becomes uncontrollable ("dead") and the equipment becomes a pile of metal given for tearing from short circuit currents.
Rescue shutdown from proprietary relay protection and automation (RPA) devices is not possible, there is only hope for long-distance shorting, acting after a long period of time, during which the equipment is finally damaged and needs a long repair or replacement.
In some cases, long-distance redundancy can be insensitive, for example, with a short circuit "behind the transformer", after which the entire substation burns with a "blue flame". However, a reliable power supply system with working current is an "expensive pleasure".
At large substations and power plants with a voltage of 110-500 kV, direct current systems are created with charging and charging rectifiers and storage batteries, as well as backup sources of energy, such as diesel generators. An external power source is arranged through a backup line or a backup transformer for their own needs. All this requires capital expenditure and operating costs for maintenance.
The smaller the power of the facility, the more difficult it is to organize a reliable power supply. And in the absence of permanent operational personnel, the problems increase by an order of magnitude.
To solve these problems, devices for relay protection and automation are produced, which are powered by current transformers. When short-circuit currents occur, relay protection devices ensure that they will trip the damaged connections. In addition, venting schemes are used, during an emergency, the tripping electromagnets are connected to the current transformers.
However, even when such relays are used, power supplies are often used to organize supply circuits for relay protection devices containing a large number of high-voltage capacitors. These power supplies require proper maintenance and certain conditions in terms of temperature, humidity, etc.
The most successful proposal is the PC80 series relay, for the operation of which there is no need to use additional power supplies, since all elements and converters are located in the relay housing. This solution greatly facilitates all issues of reliable operation.If the modification of the relay with the required range of secondary currents is correctly selected, which allows the necessary settings to be realized, then reliable operation is ensured and no problems arise.
Circuit diagram of the PC 80
Currently, the PC80 series relay is mainly produced in a microprocessor version (PC80M2M), which significantly increases the reliability of the product, mainly by reducing the number of radio components and, accordingly, the number of connections and contacts.
This statement validates a simple example of entering and storing set values. Although setpoints are entered manually using microswitches, memorization and storage is done by flash memory. Even if the microswitch loses or loses contact, the flash memory settings will remain unchanged.
The removal should be noted especially. The connection of the disconnecting electromagnets of the circuit breaker to the current circuits of the current transformers is a very important operation that must be done in a few milliseconds, and the electromagnet of the circuit breaker must flow around the secondary current for the time required to open the the breaker, not strictly fixed in advance. All this is realized in the relays of the PC80 series:
1. Disarming is done using a non-contact triac element.
2. The triac closes for a short time, an order of magnitude less than the operating time of each relay.
3. As long as the secondary current from the current transformer exceeds the relay setting, the triac closes. The current drops below the setting only after the circuit breaker's main power contacts are disconnected (ie after it has been turned off).
It should be noted that protective functions are provided in various modifications of the relay: current interruption (TO), overcurrent protection (MTZ) with current-dependent and current-independent characteristics, ground fault protection (ZNZ), as well as functions of blocking, automatic reclosing, circuit breaker failure protection. Using various modifications of the relays of the PC80 series, it is possible to provide the construction of the protections necessary for 6-10-35 kV connections on the basis of one relay without organizing the operating current.
This most valuable quality of the PC80 series relay is confirmed by the constant demand of relay protection enterprises and services for such modifications as RS80M2M-14, 12, 8. The reliable operation of the PC80 series relay for almost 20 years confirms the correctness of the chosen technical solutions during its creation.
Currently, our enterprise RZA SYSTEMS LLC, using modern production methods and constantly improving technologies, has the ability to systematically reduce costs and improve product quality, which in turn allows us to reduce prices for consumers to the level of prices of electromechanical relays.
By reducing the price of PC80, users get real savings in the modernization of the electromechanical part of relay protection and automation, during major repairs with the replacement of secondary switching, current repairs with the need to replace electromechanical relays of the RT-80 type, as well as in the new construction of complete transformer substations and other facilities without organizing a working current system...
In addition, RZA SYSTEMS is ready to provide comprehensive technical support to design and operating organizations in terms of providing typical wiring diagrams for various types of switches, as well as technical advice on the installation, configuration and operation of the PC80.