| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise caused by electromagnetic sounds of an AC filter reactor in an AC power unit formed from an inverter device to which an AC filter circuit is connected, without changing a material for a core of the reactor.SOLUTION: In order to fix a voltage waveform to be outputted from the inverter device for each term of a modulation wave, a carrier wave fundamental frequency is made into an integer multiple (N-fold) of a modulation wave frequency and a carrier wave and the modulation wave are synchronized. In order to reduce noise, when changing a carrier wave frequency, a manipulated variable for increasing/decreasing the carrier wave frequency is added to the carrier wave fundamental frequency. In order to maintain the synchronism of the modulation wave and the carrier wave, a total sum of manipulated variables for increasing/decreasing the carrier wave frequency for each term of the modulation wave is made into zero. |
