Modular multi-level converter with full-bridge cell fault current blocking for wind-turbines
AssigneeVestas Wind Systems A/S
InventorPhilip Carne Kjær
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Abstract
Embodiments herein describe a power converter in a wind turbine that includes a rectifier and an inverter. The rectifier includes a plurality of phase legs where each phase leg includes a plurality of full bridge cells configured to block fault current from flowing from a generator through the rectifier. Moreover, the wind turbine does not have any circuit breaker between the rectifier and the generator. The inverter also includes a plurality of phase legs where each phase leg includes a plurality of full bridge cells configured to block fault current from flowing from a transformer through the inverter. Moreover, the wind turbine does not have any circuit breaker between the inverter and the transformer.
Claims15
A wind turbine, comprising:
- a generator;
- a transformer;
- a power converter coupled between the generator and the transformer, wherein the power converter comprises:
- a rectifier coupled to the generator, wherein the rectifier comprises a first plurality of phase legs, wherein each of the first plurality of phase legs comprises a first full bridge cell, wherein, in response to a first current detector positioned between the generator and the rectifier detecting a first fault current flowing from the generator towards the rectifier, all transistors of the first full bridge cell are deactivated to block the first fault current from flowing from the generator through the rectifier, and wherein there is no circuit breaker between the rectifier and the generator;
- and
- an inverter, wherein an input of the inverter is coupled to the rectifier via a direct current (DC) link and an output of the inverter is coupled to the transformer, wherein the inverter comprises a second plurality of phase legs, wherein each of the second plurality of phase legs comprises a second full bridge cell, wherein, in response to a second current detector positioned between the inverter and the transformer detecting a second fault current flowing from the transformer towards the inverter, all transistors of the second full bridge cell are deactivated to block the second fault current from flowing from the transformer through the inverter, and wherein there is no circuit breaker between the output of the inverter and the transformer.
A wind turbine, comprising:
- a generator;
- a power converter coupled between the generator and a transformer, wherein the power converter comprises:
- a rectifier coupled to the generator, wherein the rectifier comprises a first plurality of phase legs, wherein each of the first plurality of phase legs comprises a first full bridge cell, wherein, in response to a first current detector positioned between the generator and the rectifier detecting a first fault current flowing from the generator towards the rectifier, all transistors of the first full bridge cell are deactivated to block the first fault current from flowing from the generator through the rectifier, and wherein there is no circuit breaker between the rectifier and the generator;
- and
- an inverter, wherein an input of the inverter is coupled to the rectifier via a direct current (DC) link and an output of the inverter is coupled to the transformer, wherein the inverter comprises a second plurality of phase legs, wherein each of the second plurality of phase legs comprises a second full bridge cell, wherein, in response to a second current detector positioned between the inverter and the transformer detecting a second fault current flowing from the transformer towards the inverter, all transistors of the second full bridge cell are deactivated to block the second fault current from flowing from the transformer through the inverter, and wherein there is no circuit breaker between the output of the inverter and the transformer.
A method implemented in a wind turbine, wherein the wind turbine comprises a power converter coupled between a generator and a transformer, the method comprising:
- detecting, by a first current detector positioned between the generator and the power converter, a first fault current flowing from the generator towards a rectifier in the power converter, wherein the rectifier is coupled to the generator, wherein the rectifier comprises a first plurality of phase legs, and wherein the first plurality of phase legs comprises a first full bridge cell;
- detecting, by a second current detector positioned between the power converter and the transformer, a second fault current flowing from the transformer towards to an inverter in the power converter, wherein an input of the inverter is coupled to the rectifier via a direct current (DC) link and an output of the inverter is coupled to the transformer, wherein the inverter comprises a second plurality of phase legs, and wherein the second plurality of phase legs comprises a second full bridge cell;
- in response to the first current detector detecting the first fault current, deactivating all transistors of the first full bridge cell to block the first fault current from flowing from the generator through the rectifier, wherein there is no circuit breaker between the rectifier and the generator;
- and
- in response to the second current detector detecting the second fault current, deactivating all transistors of the second full bridge cell to block the second fault current from flowing from the transformer through the inverter, wherein there is no circuit breaker between the output of the inverter and the transformer.
Dependencies are inferred from the claim text.