| 摘要 |
PURPOSE:To provide a rapid response characteristic by installing separately a controlling system which keeps a dc voltage of a smoothing capacitor constant for PWM-controlling an output voltage of a PWM inverter in obedience to a reactive power command. CONSTITUTION:An output voltage of an inverter (IV) 2 is PWM-controlled. In order to generate a pulse width command signal of a PWM, reactive power is detected by a reactive power detector 8 and using a deviation of the detected reactive power from a reactive power reference signal, an output voltage command signal of the IV 2 is generated by a reactive power controller 10. Then, when an output signal of a dc voltage detector 9 fluctuates, a dc voltage controller 17 detects a deviation of a dc voltage reference signal and sends out a dc voltage correction signal. When this command signal is positive, an output phase of a PLL circuit 18 is allowed to lag synchronously with an ac power system 5 and thereby the phase of the PWM is allowed to lag for running active power into the smoothing capacitor 1 and increasing a dc voltage. |
