Fault ride-through system and ride-through method for doubly-fed induction fan under DC commutation failure

Abstract

The invention discloses a doubly-fed induction fan fault ride-through system and a ride-through method when DC commutation fails. converters, DC unloading circuits, grid-side converters, inductors, transformers and grids. The fault ride-through system of doubly-fed induction fan under DC commutation failure proposed by the present invention limits the rotor overcurrent caused by continuous faults, and limits the rotor overvoltage through the DC unloading circuit, and designs an improved control strategy for the rotor side converter, which not only It can absorb or send out inductive reactive current, and can use the rotor-side converter to accelerate the decay of transient flux linkage, which improves the low-high voltage continuous fault ride-through capability of double-fed induction fans.

Description

technical field [0001] The invention belongs to the technical field of doubly-fed induction fan equipment, and in particular relates to a fault ride-through system and a ride-through method of a doubly-fed induction fan when DC commutation fails. Background technique [0002] In the field of doubly fed induction fan equipment technology, doubly fed induction generator (DFIG) is still and will continue to be the mainstream model of wind power plants located in the HVDC sending-end AC system. However, when the commutation failure occurs in the HVDC system inverter station, it may cause continuous faults of the busbar of the wind farm at the sending end to be low first and then high. The direct connection between DFIG and stator leads to high sensitivity of DFIG to voltage faults. In the context of large-scale wind power grid integration, it is necessary to ensure that wind turbines can ride through continuous faults of low and high voltages to prevent serious degradation of p...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the fault ride-through research of existing doubly-fed induction fans only considering a single low-voltage fault or high-voltage fault, lacking a low-high-voltage continuous fault protection scheme, and the existing short-term continuous voltage changes lead to Due to the problem that the reactive power control scheme of the doubly-fed induction fan cannot output the dynamic reactive current required by the grid-connected standard of the fan in time, a fault ride-through system and a ride-through method for the doubly-fed induction fan under the failure of DC commutation are proposed

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