Generator AVR automatic voltage regulator

·Generator automatic voltage regulator AVR's main function is to precisely control and adjust the voltage of the machine and the reactive power of generator, it react to rapid excitation voltage, the response time of a few milliseconds.Mainly by the measuring comparison, integrated amplifier and phase shift trigger three basic units.

, measuring comparison unit used to measure after transformation of dc voltage proportional to the voltage of the generator, and comparing with the corresponding voltage setting value, get deviation;

Voltage deviation signal is input to the integrated amplifier unit, integrated amplifier plays a role of integrated amplifier unit of measurement signal.

The phase-shift trigger unit, according to the change of the input control signals, change the output to the thyristor trigger pulse, change the conduction Angle, to control the output voltage of the thyristor, in order to adjust the excitation current of generator.

AVR: automatic voltage regulator;

FCR: the excitation current regulator;

BFCR: backup excitation current regulator;

UG: generator voltage of the pattern in measuring signal;

IG: signal generator stator current measurements;

IF: the excitation current;

·Generator excitation regulator(AVR) using digital microcomputer type, installed in the AVR reactive power, power factor and other automatic adjustment function.Excitation regulator has been low excitation limit, overexcitation protection, excitation limit, power system stabilizer, V/H restrictions and rotor over voltage protection and PT wire break closure protection unit;The additional features include one-point earthing protection of the rotor, the rotor temperature measurement, serial communication module, jumper, DSP intelligent flow, shaft voltage burr absorption equipment, etc.

·Two identical and independent road automatic excitation regulator parallel operation, can automatically track each other between the two road tunnel, when the regulator channel failure all the way, can run automatic bumpless switch to another channel.Manual and automatic circuit should be able to automatic tracking each other;When automatic circuit fault automatically the undisturbed switching to manual.CT and PT are two way independent of the input circuit.

Generator automatic voltage regulator AVR main switch between 1 and 2 in the main

This kind of excitation system has two completely independent regulator and control channel (channel 1 and channel 2).Two channels are exactly the same, so you can freely choose the channel 1 or 2 as working channel.Alternate channels (not work) always work automatically tracking channel.Basically, in addition to the following situation, channel switch can at any time:

If the working channel failure is detected, will automatically emergency switch to the second channel.Then, until troubleshooting may cut back on failure.

Mixer channel fault if you don't work, from work channel to not work the manual switch is impossible.

If a channel down, the generator voltage and dynamic changes.However, immediately automatically switch to the channel does not work, this not work channel should not follow dynamic disturbance of the generator voltage.In order to prevent this from happening, not working channel is relatively slowly with the generator voltage, and with a delay.

Channel mixer should consider from the work to the work not manual switch delay characteristics of the corresponding channel.Directly following the voltage change of generator, the switch has a short delay.This method can achieve the undisturbed in every occasion.

Generator automatic voltage regulator AVR main switch between automatic/manual mode

The excitation system is characteristic of every main has an automatic controller (automatic mode) and a manual adjuster (manually).In automatic mode, the generator voltage regulation, therefore, produce a constant voltage on the power pattern in end.On the other hand, in manual mode, the generator excitation magnetic field (current)

Constant, as the change of generator load, generator excitation (magnetic current set point) must be manually adjusted, so that the generator voltage is constant.Basically, the regulator does not work is always follow work regulator, so at any time between operation mode switch are possible.

Generator automatic voltage regulator AVR to switch to the emergency channel

In addition to the two main excitation system also added two emergency channel.Similar emergency channel and the main way of manual, equipped with a field current regulator.In addition to the excitation current regulator, emergency channel also equipped with overvoltage protection and independent of the main trigger pulse controller.Inserted into the main overvoltage protection plug-in backup protection role.Emergency channel of the effect of excitation current regulator and the main excitation

Magnetic current regulator is phase is only with adjusting excitation current.Is the emergency channel is just adjust the excitation current, rather than adjusting the generator voltage.

Emergency channel of excitation current regulator automatically follow the main, therefore, in the case of a failure in the main, automatically switching without disturbances.From main to emergency channel manually switch can only be conducted by authorized special operations personnel.Two regulator with adjustment to cut back to the main channel.

Overlay control: reactive power regulator/power factor controller input/out

If you select automatic mode and generator is connected to the grid, you can switch to the reactive power controller (Q)/power factor controller (cosPhi).Reactive power controller (Q)/power factor controller (cosPhi) is the upper controller voltage regulator, and only in running slowly.Therefore, will not affect the upper controller, a fault of short-term or voltage regulator at work.All the limitations of the automatic device as well as the original work, if necessary can control voltage regulator includes upper regulator.

The characteristics of the reactive power controller/power factor controller is its own given point can be set (given point integrator).When upper regulator disconnect, given point set is always follow the actual value (current reactive power Q/the power factor of the current).This means that the generator operation points of transition from the voltage regulator to the upper controller to work immediately.But only in the upper controller set point by who raise/LOWER LOWER order adjusted, reactive power Q/power factor also change accordingly.