Low-voltage traversing control method for double-fed wind power generation system

Abstract

The invention discloses a low-voltage traversing control method for a double-fed wind power generation system. The method comprises the following steps of: 1) detecting zero frequency transient flux component of a motor; 2) when the motor has zero frequency transient flux component outburst, controlling a rotor current transformer and a network current transformer, and attenuating the zero frequency transient flux components of the current transformers; and 3) controlling torque current and power grid reactive compensation current to inhibit the growth of harmful voltage and prevent the formation of harmful current. The method can really realize the elimination of the transient flux caused by sudden decline and sudden rise of a stator voltage and inhibit negative sequence current so as to avoid offline of the fan power generation system at the same time of protecting the rotor current transformer and the network current transformer; meanwhile, by the method, double times ultrahigh dangerous voltage of rotor induction caused by zero frequency transient flux superposition when the voltage is recovered can be prevented, and power grid-friendly intelligent low-voltage traversing is realized.

Description

technical field [0001] The invention relates to a low-voltage ride-through control method for a double-fed wind power generation system, and belongs to the field of wind power generation new energy. Background technique [0002] Wind power technology is gaining momentum in power grids worldwide due to its non-polluting and renewable nature. Among many wind power generation schemes, variable speed constant frequency double-fed AC power generation system and permanent magnet direct drive power generation system are currently the mainstream wind power generation electrical solutions due to their respective excellent characteristics. Due to the need to use a large number of permanent magnets and full power converters, the high cost of the permanent magnet direct drive system makes it difficult to popularize. The doubly-fed power generation system is cheap to manufacture, but because the generator stator is directly electrically connected to the grid, when the grid voltage sudde...

AI Technical Summary

Problems solved by technology

Although this technology is partially effective, it has many disadvantages: first, the additional hardware protection device increases the manufacturing cost; second, the switching of the protection circuit itself causes harmful impact to the system; in addition, the short-circuit operation of the rotor causes the motor to absorb A large amount of reactive power, resulting in a more severe voltage drop

Although there are many software control methods proposed at present, none of them can achieve the effect of practical application.

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