Control device for power conversion apparatus and resistor for power conversion apparatus
A control device for a power conversion apparatus and a resistor for a power conversion apparatus that can suppress a cross current between a plurality of power converters. A control device for a power conversion apparatus includes, in a state that AC sides of a plurality of power converters are connected in parallel without DC sides of the plurality of power converters being connected in parallel: a voltage recognition unit configured to recognize a voltage to ground on a DC side of a power converter, being an object to be controlled; and a controller configured to control, based on the voltage to ground on the DC side recognized by the voltage recognition unit, a DC voltage of the power converter, being the object to be controlled, such that the voltage to ground on the DC side of the power converter, being the object to be controlled, is further reduced.
1. A controller for a power convertor belonging to a group of power convertors, each power convertor having a DC side connected to a power supply and an AC side connected to a grid in parallel with other power convertors in the group, the controller comprising:
processing circuitry configured to:
in a state where a positive electrode or a negative electrode on the DC side of each power converter is connected to a common potential point via a resistor, recognize a voltage to be applied to the resistor connected to a target power converter, and
based on the recognized voltage, control a DC voltage of the target power converter to reduce a magnitude of the voltage applied to the resistor connected to the target power converter.
2. The controller for a power convertor according to claim 1 , wherein the processing circuitry is further configured to control the DC voltage of the target power converter based on the recognized voltage to reduce a magnitude of an excess of the voltage applied to the resistor connected to the target power converter with respect to a predetermined threshold.
3. A controller for a power convertor belonging to a group of power convertors, each power convertor having a DC side connected to a power supply and an AC side connected to a grid in parallel with other power convertors in the group, the controller comprising:
processing circuitry configured to:
in a state where a positive electrode or a negative electrode on the DC side of each power converter is connected to a common potential point via a resistor, recognize a voltage to be applied to the resistor connected to a target power converter, and
based on the recognized voltage, control an output zero-phase voltage of the target power converter to reduce a magnitude of the voltage applied to the resistor connected to the target power converter.
4. The controller for a power convertor according to claim 1 , wherein the processing circuitry is further configured to control the output zero-phase voltage of the target power converter based on the recognized voltage to reduce a magnitude of an excess of the voltage applied to the resistor connected to the target power converter with respect to a predetermined threshold.
5. The controller for a power convertor according to claim 1 , wherein the processing circuitry is further configured, in a state where the positive electrode or the negative electrode on the DC side of each power converter is connected to a ground as the common potential point via the resistor, to recognize the voltage to be applied to the resistor connected to the target power converter.
6. The controller for a power convertor according to claim 3 , wherein the processing circuitry is further configured, in a state where the positive electrode or the negative electrode on the DC side of each power converter is connected to a ground as the common potential point via the resistor, to recognize the voltage to be applied to the resistor connected to the target power converter.