Grid-side converter control method for doubly-fed generators when grid voltage is unbalanced

Abstract

The invention relates to a grid-side converter control method of a dual-feed motor under voltage unbalance of a power grid. The method include steps of building positive and negative order models according to current dual-loop control of an inner loop of a grid-side converter (GSC) under the voltage unbalance of the power grid, and calculating the grid-side current reference value under different control goals; based on a Hamilton with dissipation (PCHD) model with controlled port, applying internet and damping distribution passivity control (IDA-PBC) method, designing a GSC passivity controller; specific to parameter perturbation, disturbance and other uncertain factors of the current loop in the controller, adding a state observer based on an inner model control (IMC) on the basis of the passivity control; optimizing the observer parameter by a pole assignment method, realizing the current compensation control so that the current steady-state wave motion is small. Compared with the prior art, the grid-side converter control method has the advantages of advanced theory, fast dynamic response speed, strong robustness, and so on.

Description

technical field [0001] The invention relates to a distributed power generation technology, in particular to a grid-side converter control method of a doubly-fed motor when the grid voltage is unbalanced. Background technique [0002] With the increasing impact of wind turbines on the stability of the power system, it is particularly important to ensure that the wind turbines do not run off-grid when the grid voltage is unbalanced. Among numerous wind power generators, Doubly Fed Induction Generator (DFIG) is widely used because of its relatively low cost. The rotor of DFIG adopts two PWM converters, namely the rotor side converter (Rotor-Side Converter, RSC) and grid side converter (Grid-Side Converter, GSC). Since the two converters are connected through the intermediate DC bus and large capacitors, the independent decoupling control of the grid side can be realized through the grid-side converter, the control target can be obtained, and the control quality can be improved...

AI Technical Summary

Problems solved by technology

However, passive control is established by ignoring the perturbation of inductance and resistance parameters in the line, and the internal and external disturbances of the rectifier. Therefore, the control effect of the simple interconnection and damping configuration passive control strategy on the grid side will be affected

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