| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power conversion system, which is configured by connecting AC side of a single-phase sub inverter in series to a three-phase main inverter, capable of suppressing fluctuations in DC voltages of the sub inverter even when changing an effective power command or a reactive power command.SOLUTION: A controller 20 makes a main inverter 4 output a main voltage pulse 26 of one pulse at every half period of a system voltage so that a voltage Vs of a sub inverter 5 becomes a set voltage and PWM-controls the sub inverter 5, and executes switching between the following two control modes: a control mode for controlling a pulse duration of the main voltage pulse 26 and a control mode for controlling an output phase of the main voltage pulse 26, on the basis of an effective power command or a reactive power command. |
