ISLANDING OPERATION DETECTION METHOD, ISLANDING OPERATION DETECTION DEVICE, AND DISTRIBUTED POWER SUPPLY SYSTEM

摘要

To reliably detect an islanding operation in a high speed, including a power-factor output condition.SOLUTION: According to an islanding operation detection method, an islanding operation detection device, and a distributed power supply system, in order to increase the detection sensitivity for the change of harmonic voltage, the change of harmonic voltage as a vector quantity including angle information is calculated by a harmonic voltage vector calculation section 58a and an islanding operation preliminary determination section 58b, not by the change of amplitude or effective value of the harmonic voltage. When the change of the harmonic voltage exceeds a prescribed threshold value caused by a sudden change and the like, a preliminary detection for an islanding operation is carried out, and a control for accelerating the change of system frequency is carried out by a frequency change acceleration control section 58c.SELECTED DRAWING: Figure 1