Asymmetric operation method of direct-driven wind power converter and based on PIR controller

Abstract

The invention relates to a direct-driven wind power converter grid-side control strategy by utilizing a PIR controller to restrain output power fluctuation or direct current bus voltage fluctuation. The three-phase voltage and the three-phase current of a grid connection point are detected and transformed; the direct current voltage value is detected, the direct current given value is worked out, and the active power mean value at the direct current side is further obtained; an appropriate control object is selected in dependence on on-site requirements, and current given values in the rotating coordinate system are calculated; the negative-sequence current value is converted to be a value in the positive sequence rotating coordinate system and then is added to the positive sequence current value to obtain a current given value of a d axis and a q axis, current actual measurement values are subtracted from the current given values of the d axis and the q axis, and voltage reference values in the rotating coordinate system are obtained through the PIR controller; and the voltage reference values are added to decoupling compensation voltages, and the added voltages are transformed to obtain voltage signals in the two-phase static coordinate system, and the voltage signals are modulated by SVPWM to generate switching signals for controlling grid-side converters. Asymmetric operation of a direct-driven wind turbine generator is achieved on the premise that system hardware is not greatly changed, and balanced active power or direct current bus voltages is / are output.

Description

technical field [0001] The invention relates to the field of direct-drive generator control, in particular to a control operation method of a direct-drive wind generator grid-side converter based on a PIR controller. Background technique [0002] The direct-drive wind turbine is directly driven without the speed-increasing gearbox, and has the advantages of high reliability, low maintenance cost, and high power generation efficiency. Direct-drive wind turbines use full-power converters, and the grid-side converters are connected to the power grid. Therefore, the unbalance of the grid voltage may cause the unbalance of the current of the wind turbine, as well as the fluctuation of output power and torque. In severe cases, even The wind turbines will have to be disconnected from the grid. [0003] In the technical regulations for connecting wind farms to the power grid that have been promulgated in my country, it is clearly emphasized that the negative sequence voltage unbala...

AI Technical Summary

Problems solved by technology

However, this scheme needs to embed a second-order notch filter in the current loop to separate the positive and negative sequence components. The introduction of the notch filter will cause decomposition delay and error, and the structure of the traditional vector control system will be greatly changed.

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