Isolated operation prevention device for distributed power supply and interharmonic detection method

摘要

A power fluctuation monitoring unit which monitors and detects the power fluctuation at a receiving point 9 by means of the measurement results of the voltage at injection point 14 of an intermediate-order harmonic current and the current at incoming line 10, a power compensation unit which forms the compensation power injection signal for canceling out the power fluctuation based on the detection results of the power fluctuation, and an inverter device 18 which is driven and controlled by the signal resulting from the addition of the intermediate-order harmonic current injection signal and the compensation power injection signal and injects the intermediate-order harmonic current and the compensation power into the injection point, are equipped.