Generator automatic voltage regulator Definition:Maintain synchronous generator voltage of the voltage at a predetermined value or change according to the plan of a kind of synchronization Generator regulator.When the synchronous motor terminal voltage and reactive power changes, according to the corresponding output current feedback signal automatic control exciter, automatically adjust the synchronous motor in order to achieve the purpose of the terminal voltage and reactive power.

Synchronous generator automatic voltage regulator (AVR) can be divided into: SCR automatic voltage regulator、TD1 carbon resistance type automatic voltage regulator, automatic pressure regulating phase compound excitation, and three categories.The following are the threesynchronous The working principle of the generator automatic voltage regulator。

1, SCR automatic voltage regulator

This way of regulating refers to the use of series or incorporated into the excitation control circuit of SCR excitation current, so that the output voltage of generator automatically adjust along with the change of load.Thyristor control mode has a variety of: one is to use the unijunction transistor oscillation circuit of trigger pulse, change of capacitance charging voltage, so as to control the trigger pulse of time, change the conduction Angle of silicon controlled rectifier;2 it is using the triode switch characteristics, change of capacitance charging voltage, the control of the triode trigger conduction time, also can control the conduction Angle of silicon controlled rectifier.

2, TD1 carbon resistance type automatic voltage regulator

This way of regulating in 6135 lh-zd type used on diesel generator set, its working principle is: when the generator load is rating, automatic voltage regulator stable, then the generator excitation current, voltage, and the exciting current is stable.Motor load increase, lead to voltage is reduced, the automatic voltage regulator begin to regulate carbon resistance, the resistance is reduced, so that the generator excitation current increase, prompted the generator output voltage rises;On the other hand, reduced the load, and the automatic voltage regulator adjusting carbon piece of resistance value increases, so as to reduce the excitation current, the voltage drop.

3, automatic phase compound excitation voltage regulation

For starting and load changes in the operation of large special equipment, adopts the automatic regulating phase compound excitation method is better, so in the special equipment in the power supply, generator control part adopts automatic regulating phase compound excitation method more.Phase compound excitation, the basic principle of the automatic voltage regulator is: when the generator no-load, armature tapped winding through the remanence voltage linear reactor 90 ° phase shift, after three-phase bridge rectifier rectifier excitation output dc current flow to the field winding.When the remanence voltage is too low, can use direct current (dc) for charging.When the generator with the load, the load current is by a winding of current transformer and a primary winding current is proportional to the relationship between the secondary current, the current can vary with different power factor of load corresponding increase or decrease the size of the field current required.In conjunction with the appropriate parameters, supply for generator excitation current, it can automatically adjust the voltage, the voltage stability in a certain scope.Due to its characteristics, more applied in the engineering construction and special equipment.