Adjusters
Overview:
BL4U is a half-wave phase-controlled thyristor type Automatic Voltage Regulator(Automatic Voltage Regulator) andforms part of the excitation system for a generator.ln addition to regulating the generator voltage, the Automatic Voltage Regulator BL4-U circuitry includes under-speedprotection features. Excitation power is derived directly from the generator terminals.Positive voltage build up from residual levels is ensured by the use of efficient semiconductorsin the power circuitry of the Automatic Voltage Regulator
Automatic Voltage Regulator BL4-U.The Automatic Voltage Regulator Automatic Voltage Regulator BL4-U is linked with the main stator windings and the exciter field windings toprovide closed loop control of the output voltage.In addition to being powered from the main stator, the Automatic Voltage Regulator BL4-U also derives a samplevoltage from the output windings for voltage control purposes. In response to this samplevoltage, the Automatic Voltage Regulator Automatic Voltage Regulator BL4-U controls the power fed to the exciter field, and hence the mainfield, to maintain the machine output voltage within the specified limits, compensating for load,speed, temperature and power factor of the generator.A frequency measuring circuit continually monitors the generator output and provides outputunder-speed protection of the excitation system, by reducing the output voltage proportionallywith speed below a pre-settable threshold.A manual adjustment is provided for settingof the under frequency roll off point,(UF).This can easily be changed to 50 or 60 Hz in thefield two position jumper.Provision is made for the connection of a remote voltage potentiometer, allowing the user finecontrol of the generator's output.
MAIN FUNCTIONS :
The main functions of the Automatic Voltage Regulator are:Potential Divider and Rectifier takes a proportion of the generator output voltage andattenuates it. This input of resistors includes the