DC CHOPPER AND DC CHOPPING METHOD FOR DOUBLY FED INDUCTION GENERATOR SYSTEM
First Claim
1. A DC chopper suitable for a DFIG system comprising a converter and a DFIG, the DC chopper comprising:
- a control unit having at least one input terminal and an output terminal, wherein the at least one input terminal of the control unit is electrically coupled to two ends of a DC capacitor of the converter, so as to detect a DC voltage; and
a power circuit electrically coupled to the converter, the DFIG and the control unit, wherein the power circuit comprises;
an input terminal coupled in parallel to the DC capacitor of the converter, wherein the DC capacitor is located between a grid-side inverter and a generator-side inverter of the converter;
an overvoltage protection module coupled to the input terminal of the power circuit, wherein the overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element which are coupled in series, and the switch element is electrically coupled to the output terminal of the control unit;
a rectifier module coupled to the overvoltage protection module in parallel; and
an output terminal coupled to the rectifier module and the DFIG,wherein, when a grid voltage of the DFIG system drops, the output terminal of the control unit outputs a corresponding control signal to drive the switch element to be on or off; and
the output terminal of the power circuit absorbs a portion of rotor inrush current from the DFIG, so as to implement over-current protection on the generator-side inverter.
1 Assignment
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Accused Products
Abstract
A DC chopper comprising a control unit and a power circuit and a DC chopping method for a DFIG (doubly fed induction generator) system are provided. The input terminal of the control unit is coupled to a DC capacitor of a converter to detect a DC voltage. The power circuit includes input terminals, an overvoltage protection module, a rectifier module and output terminals. The overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element, and the rectifier module is coupled in parallel to the overvoltage protection module. When a grid voltage drops, the control unit outputs a corresponding control signal to drive the switch element to be ON or OFF, and the output terminal of the power circuit absorbs a portion of rotor inrush current, so as to impose over-current protection.
18 Citations
17 Claims
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1. A DC chopper suitable for a DFIG system comprising a converter and a DFIG, the DC chopper comprising:
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a control unit having at least one input terminal and an output terminal, wherein the at least one input terminal of the control unit is electrically coupled to two ends of a DC capacitor of the converter, so as to detect a DC voltage; and a power circuit electrically coupled to the converter, the DFIG and the control unit, wherein the power circuit comprises; an input terminal coupled in parallel to the DC capacitor of the converter, wherein the DC capacitor is located between a grid-side inverter and a generator-side inverter of the converter; an overvoltage protection module coupled to the input terminal of the power circuit, wherein the overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element which are coupled in series, and the switch element is electrically coupled to the output terminal of the control unit; a rectifier module coupled to the overvoltage protection module in parallel; and an output terminal coupled to the rectifier module and the DFIG, wherein, when a grid voltage of the DFIG system drops, the output terminal of the control unit outputs a corresponding control signal to drive the switch element to be on or off; and the output terminal of the power circuit absorbs a portion of rotor inrush current from the DFIG, so as to implement over-current protection on the generator-side inverter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification