| 摘要 |
PURPOSE:To obtain a control circuit for an inverter which can operate stably in all frequency range by correcting reference waveform data by upper and lower short-circuit preventing periods (hereinafter referred to as 'Td') in a low frequency range and inhibiting to correct it in a high frequency range. CONSTITUTION:A Td correcting circuit 13 outputs correction data (corresponding to an average voltage to be superposed on an output voltage waveform of an inverter due to influence of Td) for reference waveform data of three phases from a reference waveform forming circuit 5 to a comparator 7 to remove the influence of the Td if a Td correction absence signal is not input. When the absence signal is input, a Td correction is inhibited, and adverse influence due to the Td correction is removed in a high frequency range in which the influence of the Td to the output voltage of the inverter is small and the influence of detecting error, etc., of a current polarity signal becomes large. |
