| 摘要 |
PROBLEM TO BE SOLVED: To increase options of a superposition harmonic order for detecting an isolated operation, in a power conversion device for distributed power supply of three phases for detecting the isolated operation by superposing a harmonic voltage on an AC voltage.SOLUTION: The present invention relates to a self-excited power conversion device for distributed power supply of three phases interconnected to a power system. The power conversion device comprises: a fundamental wave phase detection part for detecting a phase of a system fundamental wave component from an interconnection point voltage detection value that is a voltage at a system interconnection point of the power system; a harmonic voltage superposition amount calculation part for calculating a harmonic wave in a 2N-order frequency (N is a natural number that is a multiple of 3) of a frequency detected by the fundamental wave phase detection part; a harmonic voltage superposition part for superposing the harmonic wave on an output voltage command value of the power conversion device; a harmonic component extraction part for extracting a 2N-order harmonic component from an AC voltage of the interconnection point voltage; and an isolated operation detection part for detecting the isolated operation of a power converter based on a voltage amplitude of the extracted harmonic component.SELECTED DRAWING: Figure 1 |
