Patent ID: 9680368
Date: 2017-06-13
CPC Classifications: H02J,H02M

Claim:
1. A power converter that is installed between an electric power system and an energy storage device and performs AC/DC conversion with the use of an inverter, comprising: a harmonic filter in an AC circuit on the electric power system side; and a DC capacitor and a DC breaker in a DC circuit on the energy storage device side, wherein, when the energy storage device starts running, a current that is limited by a limiting resistor is given from the electric power system side to the DC capacitor, the difference between the voltage of the DC capacitor and the voltage of the energy storage device is monitored, and the power converter is connected to the energy storage device by switching on the DC breaker on the basis of the monitored difference, wherein the power converter further comprises: a first switch included in the AC circuit; a resistor, one terminal of which is connected to the first switch in series and the other terminal of which is connected to the AC terminal of the inverter via the harmonic filter; and a second switch that is connected in parallel to a series circuit of the first switch and the resistor, wherein a start control means for the power converter includes the steps of: switching on the first switch, opening the first switch when the voltage of the DC capacitor exceeds a first predefined value, and further switching on the second switch; controlling the inverter so that the difference between the voltage of the energy storage device and the voltage of the DC capacitor decreases by starting the switching of the inverter after the second switch is switched on; switching on the DC breaker if the difference between the voltage of the energy storage device and the voltage of the DC capacitor is within a predefined range; changing over an operation mode after the switch-on of the DC breaker; and controlling the inverter by using an active power command value after the operation mode is changed over.