| 摘要 |
PROBLEM TO BE SOLVED: To provide inverters which can be operated synchronously in parallel by simply connecting a plurality of DC-AC conversion circuits having simple circuit and identical configuration in parallel with each other. SOLUTION: In each DC-AC conversion circuit 1 constituting an inverter, a zero-cross detection signal is delivered from a zero-cross detection circuit 13 to a reference sine wave generation circuit 11 when the output voltage from a full-bridge inverter 9 detected by an output voltage detection circuit 10 has an instantaneous value of 0V. Since the frequency and phase of an output signal from the circuit 1 are synchronized constantly with those of a reference sine wave signal from the circuit 11, inverters can be operated synchronously in parallel by simply connecting a plurality of DC-AC conversion circuits 1 having identical configuration in parallel with each other. Furthermore, circuit of the inverter can be simplified because no PLL(phase lock loop) circuit for synchronizing the output frequency and phase nor special signal line for supplying a synchronization signal is required. |
