| 摘要 |
PURPOSE:To eliminate the variation in the torque at pulse number switching time by performing the switching of the number of pulses at the time point when the phases of the carrier signals coincide with each other. CONSTITUTION:The primary voltage of alpha-beta shaft calculated by a noninterference calculator 6 which inputs the alpha-shaft primary current set value and the beta- shaft primary current command is converted by a coordinates converter 7 into polar coordinates data, and input to a PWM waveform calculator 8. PWM pattern data is applied from a pulse pattern generator 10 and a pattern data converter 11 to the calculator 8, and the conversion of the number of the carrier pulses is executed in the phase coincident with the carrier pulse peak phase before and after the conversion. A gate circuit 9 obtains a PWM waveform of the actual phase inverter voltage in accordance with the data from the calculator 8, and the switching element of the inverter 1 is controlled ON or OFF in accordance with the voltage. |
