| 摘要 |
PURPOSE:To exellently perform inverter synchronous control, by correcting the inverter frequency setting signal fed from a frequency setting signal generating circuit depending on the output of an integration circuit, and supplying the trigger signal having the corrected frequency to the inverter. CONSTITUTION:When a commercial frequency power input (e) is restored, a pahse difference detecting circuit 20 detects the phase difference between the synchronism reference input with the output of an inverter 14, a frequency difference detecting circuit 22 detects the frequency difference of both the signals and integrates 24 of the detected output of both the circuits 20 and 22. On the other hand, a frequency setting signal generating circuit 28 generates the inverter frequency setting signal set to the specified frequency, and the output is corrected in response to the output of the circuit 24, and the trigger signal having the corrected frequency is fed to the inverter 14. Thus, with a gradual speed in which the load can follow without any hindrance, the frequency and phase of the inverter output can be synchronized with the synchronous reference input, allowing excellent inverter synchronous control. |
