REVERSE VOLTAGE DETECTING CIRCUIT FOR DECENTRALIZED POWER SUPPLY

摘要

PURPOSE:To decide the separation of an electric power system with high accuracy by vibrating minutely the AC output voltage phase of an inverter linking the power system in order to fluctuate the active power supplied to the power system from the inverter and monitoring the fluctuation of the active power to detect the separation of the power system after this separation based on the reduction of the fluctuated variable of the active power. CONSTITUTION:The AC output voltage phase (set to the voltage of an electric power system 6) of an inverter 2 linking the system 6 of a decentralized power supply 10 is minutely changed. Then the fluctuated variable of the active power supplied to the system 6 from the inverter 2 is monitored and then the separation of the system 6 is detected based on a fact that the fluctuated variable of the active power is reduced after the separation of the system 6. In this case, an active power setter 101 serving as a means which changes minutely the reactive power outputs the value proportional or virtually proportional to the generated power so that the level of the minute fluctuation of the active power can be controlled in accordance with the level of the generated power of a DC power supply 1. Thus the decision is attained with high accuracy for separation of the system 6.