| 摘要 |
PROBLEM TO BE SOLVED: To perform the high-speed control of an inverter before its parallel operation with other ones, by separating its deviation sensing means from itself and so correcting the output of its voltage control means as to suppress its output current during a fixed term after closing its circuit breaker for the purpose of its parallel operation with other ones, and by starting its balance control after the fixed term. SOLUTION: Before the parallel operation of a first inverter 2a, turning off a circuit breaker 4a, a deviation sensing circuit 9a and a multiplier 14a are separated from it to perform its separate no load operation. Then, turning on the circuit breaker 4a, a signal required in the case of its parallel operation is outputted by an input instructing circuit 13a to input the signal to the circuit breaker 4a and a timer 16. In this case, making the operation time of the timer 16 not shorter than the delay time of the circuit breaker 4a, relay switches 17a1, 17a2 are respectively turned on and turned off by the output of the timer 16 to activate the multiplier 14a. As a result, multiplying the output current of the first inverter 2a by a negative gain, its voltage control is corrected, and the deviation sensing circuit 9a is separated from it not to perform both the sensing of its current deviation and the control done by a balance control circuit 11a. By such a separate no load operation, after a fixed term, the parallel operation of the first inverter 2a with other ones is performed, keeping its high- speed voltage control response. |
