| 摘要 |
PURPOSE:To allow an inverter to perform a parallel operation directly, by being endowed with the same power dependable characteristic of frequency as an AC generator. CONSTITUTION:In a parallel operation of an inverter 1, the system is equipped with inverter blocks 27-29 each of which is composed of an individual oscillator 13, a power detector 17, a circuit 34 to change the oscillation frequency of the individual oscillator 13 according to the output power, a regulator 25 for oscillation frequency and a voltage regulator 26 of the output voltage. Between the output power and output frequency of this inverter 1 a characteristic is given when the frequency slightly drops according to the increase of the output power. In case two inverters are thus operated in parallel, either one is operated first of all into which the load is switched. Then the second one is operated and both regulators 25-26 of the second inverter 1 are regulated to coincide the frequency and the voltage to the first one. When the phase of the output voltage is coincided, both inverters are put to work in parallel. When the reactive cross current flow between both inverters is large, it is regulated so that the reactive cross current may be zero with a voltage regulation circuit 9 of either of the inverters 1. |
