| 摘要 |
PURPOSE:To stably control the output by performing a pulse width modulation by using an in-phase signal with a system proportional to the system voltage instantaneous value and a phase advance signal synchronized with the system voltage produced by an oscillator in a phase locked loop circuit. CONSTITUTION:A system voltage signal is converted by a waveform converter 1201 to a digital signal. A phase detector 1202, a low pass filter 1203, a voltage controlled oscillator 1206, and a frequency divider 1207 from a phase locked loop, and the output of the frequency divider 1207 is synchronized with the prescribed phase displacement with the system frequency. The signal returned to a sinusoidal wave by a waveform converter 1208 is divided by the output of a sample-holding circuit 1211, and used as a desired amplitude phase advance signal. |
