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

A power grid fault ride-through device for a doubly fed induction generator, comprising:

• a controller;
• a crowbar circuit comprising:
• a three-phase input end;
• a switch circuit comprising:
• a three-phase input end;
• and
• a bridge circuit comprising full-controlled power electronic devices as constituent elements;
• and
• a driving circuit;
• a doubly fed induction generator comprising:
• a generator-side converter;
• and
• a grid-side converter;
• and
• a du/dt inductance comprising a connection end;
• wherein:
• the controller is in controlled connection with the generator-side converter and the grid-side converter of the doubly fed induction generator and the crowbar circuit,
• the three-phase input end of the crowbar circuit is connected with the connection end of the du/dt inductance and the generator-side converter,
• the drive circuit is in driving connection with the switch circuit,
• the controller is in controlled connection with the drive circuit, and
• the three-phase input end of the switch circuit is connected to the three-phase input end of the crowbar circuit.

A power grid fault ride-through method for a doubly fed induction generator, where the power grid fault ride-through device for a doubly fed induction generator comprises:

• a controller;
• a crowbar circuit comprising:
• a three-phase input end;
• a switch circuit comprising:
• a three-phase input end;
• and
• a bridge circuit comprising full-controlled power electronic devices as constituent elements;
• and
• a driving circuit;
• a doubly fed induction generator comprising:
• a generator-side converter;
• and
• a grid-side converter;
• and
• a du/dt inductance comprising a connection end;
• wherein:
• the controller is in controlled connection with the generator-side converter and the grid-side converter of the doubly fed induction generator and the crowbar circuit,
• the three-phase input end of the crowbar circuit is connected with the connection end of the du/dt inductance and the generator-side converter,
• the drive circuit is in driving connection with the switch circuit,
• the controller is in controlled connection with the drive circuit, and
• the three-phase input end of the switch circuit is connected to the three-phase input end of the crowbar circuit, and
• the method comprises the steps of:
• the controller switching off the generator-side converter and triggering the crowbar circuit to achieve conduction of the switch circuit when a power grid voltage drops to a condition where a rotor current of the doubly fed induction generator rises to be equal or larger than a set conduction threshold value of the crowbar circuit.

A power grid fault ride-through method for a doubly fed induction generator, where the power grid fault ride-through device for a doubly fed induction generator comprises:

• a controller;
• a crowbar circuit comprising:
• a three-phase input end;
• a switch circuit comprising:
• a three-phase input end;
• and
• a bridge circuit comprising full-controlled power electronic devices as constituent elements;
• and
• a driving circuit;
• a doubly fed induction generator comprising:
• a generator-side converter;
• and
• a grid-side converter;
• and
• a du/dt inductance comprising a connection end;
• wherein:
• the controller is in controlled connection with the generator-side converter and the grid-side converter of the doubly fed induction generator and the crowbar circuit,
• the three-phase input end of the crowbar circuit is connected with the connection end of the du/dt inductance and the generator-side converter,
• the drive circuit is in driving connection with the switch circuit,
• the controller is in controlled connection with the drive circuit, and
• the three-phase input end of the switch circuit is connected to the three-phase input end of the crowbar circuit, and
• the method comprises the steps of:
• the controller switching off the crowbar circuit to switch off the switch circuit and the controller switches on the generator-side converter to provide reactive power support for the power grid when a rotor current of the doubly fed induction generator attenuates to be equal to or less than a set switch-off threshold value of the crowbar circuit.