Basically automatic voltage regulator for generator have a 2 mode selection.It is with full automatic function and manual function.
I already discuss about AVR function and basic operation in my last post.Please refer to basic of automatic voltage regulator.i hope it can make a clear view and understanding about AVR function in generator.
This time i want share some information about controller method that commonly used for AVR for generator.For latest design of AVR,manufacture put a two(2) selection for AVR controller mode.It is Automatic and Manual mode.
This selection of AVR controller mode depend on our system and current application for generator.I explain detail about this two AVR controller mode.
Automatic voltage regulator operation
1) Automatic control mode
For automatic mode controller is a normal selection when running in standard generator for generated power supply.This mode controlled by automatic system that designed and setting by manufacture to get standard output.
Generators are normally required to deliver from zero to rated output over a voltage range of ±5%, at power factors from 0.8–0.9 lag to 0.9 lead.
The a.v.r. setting controls must provide the appropriate range of excitation as well as a voltage down to about 85% of nominal at no-load.Accuracy of control is normally between ±2.5% and ±1% of set value over the load range.
2) Manual control mode.
For manual control mode,it usually used for back-up system from automatic mode if it malfunction or needed to manual setting for generator output.
In others situation,many bigger machine needed a huge power supply and it not sufficient excerpt generator running in automatic mode and the manual control setting only used for the initial commissioning during setup.
Most voltage regulators, when operating in automatic, are provided with ‘manual follow-up’ which ensures that the manual setting matches the automatic setting so that if failure of the automatic system causes a ‘trip to manual’ this will not result in any change of set-point.
A balance meter may be provided so that if changeover is to be made manually, a check can be made before effecting the change.Please refer to manufacture if you not sure how to used manual mode to avoid serious damage to the generator.