LEAKAGE CURRENT SUPPRESSION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a leakage current suppression circuit that uses a compact active filter applicable even to an inverter with a high voltage rating, and has favorable responsiveness.SOLUTION: A common mode voltage detection section 6 detects from a power line a common mode voltage generated by a switching operation of a power conversion apparatus. A feedback section 8 computes an amplification voltage which brings the detected common mode voltage to the same potential as a neutral potential of a DC current line. A cancellation voltage application section 10 applies the amplification voltage to the power line of the power conversion apparatus. A voltage-controlled power supply section 9 comprises a plurality of NPN transistors and a plurality of PNP transistors arranged polarity-symmetrically. The plurality of NPN transistors are connected so as to divide a voltage between the detected common mode voltage and a positive DC current side of the DC current line. The plurality of PNP transistors are connected so as to divide a voltage between the detected common mode voltage and a negative DC current side of the DC current line.