| 摘要 |
PROBLEM TO BE SOLVED: To suppress the fluctuation of transient voltage and make a stable operation with zero steady voltage deviation stably by making an adjustment by a first regulator so that the deviation of a voltage actual value from a voltage target value may be zero and making an adjustment by a second regulator so that the deviation of an AC voltage signal from a reference sine-wave signal which is the output of the first regulator may be minimum. SOLUTION: The AC voltage detected by a potential transformer 11 is rectified by a rectifier 12 and then is smoothed by a smoothing circuit 13 to obtain a voltage actual value signal. The deviation of the voltage actual value signal from a voltage target value signal set by a voltage setting device 14 is input to a first regulator 15 to adjust the deviation to zero. On the other hand, the output voltage of an inverter is input to a first signal multiplier 31 and the output of the first signal multiplier 31 and a reference sine-wave signal output from a sine-wave generating circuit 16 are compared by an adder 21 and a difference between the two signals is so adjusted by a second regulator 22 so that it may be minimum. By this method, the transient fluctuation of voltage can be held as small as possible and the deviation due to the steady fluctuaion of voltage can be made zero. |
