Liebert Corporation

Shenzhen Hopewind Electric Co. Ltd.

Quanbo Xia

Zhihua Wang

Brian Paul Heber

Bo Dong Liu

Dangsheng Zhou

Xiaojun Sheng

Steve Moran

Dansheng Zhou

Chris Crawford

Ronghui Liao

Jianyou Zeng

Yihang Lu

The invention discloses a power grid fault ride-through device and a method for a doubly fed induction generator. The device comprises a controller and a crowbar circuit, the controller is in controlled connection with a generator-side converter and a grid-side converter of the doubly fed induction generator and the crowbar circuit, a three-phase input end of the crowbar circuit is connected with a connection end of a du/dt inductance and the generator-side converter, the crowbar circuit comprises a switch circuit and a drive circuit which is in driving connection with the switch circuit, the controller is in controlled connection with the drive circuit, the switch circuit comprises a bridge circuit comprising full-controlled power electronic devices as constituent elements, and a three-phase input end of the switch circuit is connected to the three-phase input end of the crowbar circuit; and with the device, the method comprises the following steps of closing the generator-side converter and triggering the conduction of the switch circuit in case that a power grid dips to the condition that rotor current is equal to or larger than a conduction threshold value, and switching off the switch circuit in case that rotor current is equal to or smaller than a switch-off threshold value. The invention prolongs the service life of the crowbar circuit and improves the working reliability of the crowbar circuit, and has simple structure and easy implementation.

Protection device and protection method for through power network fault of double-fed induction generator

The present invention discloses a method for transmitting parallelization signals of uninterruptible power supplies, which firstly performs a serialization process on parallelization signals by a logic processing unit and then performs synchronous transmission of the parallelization signals of respective node units over a bus. The method for serial transmission of parallelization signals of uninterruptible power supplies according to the invention can be implemented with easy wiring and can achieve a strong anti-interference ability, ensure real time signal transmission over a guaranteed transmission distance and identify conveniently the failure of a parallelization line while satisfying fundamental transmission demands.

Method for transmitting parallelization signals of uninterruptible power supplies

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Shenzhen, China

Quanbo Xia