The method of testing insulation resistance based on asymmetric electric resistance bridge for direct current (DC) distribution system is proposed.

As a digital programmable chip of signal conditioning chip, PGA309 is mainly used in resistance bridge pressure sensors, it amplifies and outputs the weak signal from the sensor.

Then it introduces the rotor earth fault monitoring based on the method of resistance bridge with source, and the interturn short circuit fault monitoring in generator rotor based on stator coil.