Emerson Network Power Co., Ltd.

Shenzhen Hopewind Electric Co. Ltd.

Xiaojun Sheng

Zhihua Wang

Dangsheng Zhou

Quanbo Xia

Dansheng Zhou

Ronghui Liao

Jianyou Zeng

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 relates to a switching synchronization method of parallel converter system, wherein one of converters is the host and the others are slave converters. The host converter includes a first timer and a pulse-transmitting device, and the slave converter includes a second timer, pulse capture device, and a synchronization adjustment. At a fixed time Tk the host converter sends a synchronization pulse to the synchronization bus through the pulse-transmitting device; and in the slave converter the second timer records the time Tx of the edge of the synchronization pulse received by the pulse capture device from the synchronization bus. The synchronization adjuster adjusts the second timer of the slave converter so as to synchronize it with the first timer of the host converter in accordance with the relationship between the times Tk and Tx; and then according to a predetermined protocol, the switching carrier timer of the slave converter so as to be adjusted to synchronize with the switching carrier timer of the host converter.

Method of switching synchronization of parallel-connected converter system

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Shenzhen, China

Xiaojun Sheng