Digital Voltage Regulator Caterpillar

In some installations, a single generator is used with long feeder lines to the load. Therefore, it may be advantageous to provide line loss compensation. Line loss compensation is commonly referred to as IR compensation. In this mode, a CT must be provided in order to measure the generator current.

The parameters that are related to line loss compensation are listed below.

:01 - Generator Output Voltage

:02 - Ratio of Output Voltage to Sensing Voltage

:03 - Generator Type

:04 - Rated Generator Output Current

:05 - Current Transformer Voltage at Rated Generator Current

:06 - Knee Frequency

:15 - Voltage Gain (Line Loss Compensation)

:16 - Integral Gain

:17 - Proportional Gain

Current flowing through a long conductor causes a voltage drop due to the resistance of the wire. Therefore, the voltage at the load end of the conductor will be lower. than at the generator due to the voltage drop along the conductor. This condition is commonly referred to as line losses. In order to improve the power quality, the digital voltage regulator can compensate for the voltage drop. As generator load increases, the regulator will cause the output voltage to rise slightly at the generator terminals in order to compensate for line losses. Voltage gain (parameter :15) controls the amount of compensation. The voltage gain should be adjusted in order to yield a constant voltage at the location of the load.

If line loss compensation is desired, then the droop percentage (parameter :30) should be set to zero. The line loss compensation and the voltage gain counteract each other. If a CT is provided but line loss compensation is not desired, voltage gain (parameter :15) must be set to zero.