| 摘要 |
PROBLEM TO BE SOLVED: To obtain a drive controller for a synchronous motor having many features of a matrix converter by selecting the highest and lowest potentials of a power supply circuit and controlling a semiconductor device to be coupled with a motor. SOLUTION: When some phase of a power supply voltage is connected with a reference voltage, other two phases are not subjected to PWM control between the maximum and minimum values eU, eV of the power supply voltage but they are connected with an intermediate power supply voltage eW for some interval, when a switching is made from the maximum level eU to the minimum level eV or vice versa. Consequently, the power supply voltage is distributed to three phases, and the current waveform can be improved. Furthermore, the input power factor can be controlled by regulating the interval to be connected with the intermediate voltage eW. According to the control system, the reference voltage can be varied, depending on the polarity of the intermediate voltage eW, and thereby the power factor and the current waveform of the power supply can be controlled collectively. |
