| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power conversion unit capable of supplying stable interchanged power, by resolving a problem of the influence of interchanged power at the time of change of interchanged power command value without power flow inversion. SOLUTION: A direct current reference signal change circuit 26 is inserted into the terminal controller of a control device. The direct current reference signal change circuit 26 is provided with a polarity detecting portion 8 which detects the polarity of the direct-current voltage of a main circuit; a coincidence- of-power flow direction confirming circuit 9 which is fed with a polarity signal from the polarity detecting portion 8 and a power flow signal, checks the direction of power flow, and outputs a hold signal in case of inconsistency of polarity, and a minimum value selecting portion 7 which is fed with a hold signal and a direct current reference signal, compares them and outputs the minimum value as a direct current reference signal. |
