摘要 |
PURPOSE:To finally compensate harmonic of a power supply current by connecting a plurality of harmonic suppression inverters in parallel, and providing limiter means for limiting a harmonic compensating capacity in a controller of each inverter. CONSTITUTION:Inverter 3a-3c are operated in parallel, the inverter 3c first detects a harmonic component contained in a current I3a and compensates the harmonic. Then, the inverter 3b compensates a harmonic current contained in a current I2a, and compensates for that which cannot be sufficiently compensates by the inverter 3b, Further, the inverter 3a detects the harmonic of the current I1a and compensates for the harmonic. If all the harmonic contained in the current I3a are compensated, a power supply current Is becomes a sine wave current. |