METHOD OF CONTROLLING POWER CONVERSION SYSTEM, AND POWER CONVERSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a power conversion system configured to supply power from a DC power supply to an AC motor which significantly reduces an iron loss.SOLUTION: The power conversion system includes a DC power supply 7, a booster circuit 10 and an inverter circuit 9. The booster circuit 10 comprises only a bridge circuit 8, a capacitor 5 and a coil 6, and a switching frequency f(Hz) of pulses for turning on/off switching elements 1, 2 in the bridge circuit 8 is determined so as to satisfy 0.80×f≤f≤1.20×f, where f=1/(2&pgr;×(LC)) is given by a capacitance C (F) of the capacitor 5 and an inductance L (H) of the coil 6. The inverter circuit 9 uses six semiconductor elements A having the function of turning on/off in response to a pulse input in accordance with the number of pulses to output a voltage resulting from pulse density modulation of a voltage across the capacitor 5. A method of control thereof is also provided.