Getting Started with Automatic Voltage Regulator AVRs - regulator avr

AVR adopts digital (DAVR), its performance is reliable, and has hard interface with ASS, DEH and DCS and communication interface with DCS. It has two redundant main controllers A and B, which receive signals from different PT and CT secondary sides respectively. The output signals are amplified by pulse amplifiers A and B respectively to form trigger pulses to control the thyristor rectifier. When the working system fails, it will automatically switch to the backup system.

With two independent automatic channels. Each automatic channel has a rotor current closed loop function. The two automatic channels are used as backup for each other, and can automatically switch without disturbance in case of failure. Each channel is provided with an independent standby manual channel and meets the generator test requirements.

In addition to the more complete control functions, the excitation control system also includes:

There are two ways of automatic start and manual start;

With self-diagnosis function for hardware and software, it can detect abnormal conditions in time and provide processing steps;

It has the function of recording the transition state to provide the purpose of failure analysis and test analysis. The main controller has the function of periodically and cyclically recording control parameters, including at least 32 points of fault signal (or digital input) and 8 points of analog input (such as generator voltage, active power, reactive power and excitation current, etc.) , and the recorded items can be modified.

During normal operation, the parameters are recorded all the time. The built-in display screen can easily display the test parameters and dynamic characteristics, and the recorded parameters can also be sent to the special maintenance tool through the communication interface to display the trend in a graphic way.

AVR has at least the following limited protection functions:

- Forced inverse time limit;

- Overexcitation limit and protection;

- Underexcitation limit and protection;

- Maximum excitation current limit and protection;

- VT disconnection protection;

- V/H limit and protection, etc.;

- Power System Stabilizer (PSS) (response frequency from 0.1~2Hz).

AVR has the following basic functions: terminal voltage regulation, magnetic field voltage regulation, constant reactive power regulation, constant power factor regulation, reactive power compensation, etc.

The AVR has an analog measurement port for the output signal of the regulator and an analog signal input port for the voltage addition point, so as to measure and set the AVR characteristic parameters. AVR has analog quantity measurement port of PSS output signal and analog quantity signal input port of PSS input point, in order to measure and set PSS characteristic.

AVR meets the requirements of anti-electromagnetic interference test in GB/T17626 electromagnetic compatibility test and measurement technology. The AVR cabinet uses natural ventilation and is equipped with a cooling fan. The protective grounding and working grounding of the cabinet are separated. The protection class of the AVR cabinet is IP31. The AVR cabinet can operate normally when the ambient temperature is 45 degrees.

The AVR adopts the DC regulated power supply of the device itself. The DC regulated power supply device itself is reliable and requires two independent external power supplies to run in parallel.