| 摘要 |
PURPOSE: To prevent the excess current at the time of starting a PWM converter by so controlling a converter input voltage vector as to reduce the difference voltage vector between the voltage vector of an AC power source and the input voltage vector of the converter when a diode rectifying mode is switched to a PWM control mode. CONSTITUTION: An AC power source is tuned ON in the state that a PWM signal is suppressed, and a smoothing capacitor is initially charged up to a diode rectifying diode. Thereafter, the output of the integrator 18b of a PI compensator 15a is always set to negative or a negative limit value by integrator output initializing means 23 until a converter start command 22 is output. Since the initial value of the integrator 18b is smaller than the output of a proportional gain 20b even if the effective power current command Iq* is positive, a q-axis voltage correct amount ΔVq becomes negative. Then, at the time of starting the converter, the converter input voltage is increased with the diode rectifying voltage of low DC voltage. As a result, the difference voltage between the power source voltage and the converter input voltage becomes low, and an excess power source current does not flow. |
