Operation characteristics of doubly fed wind turbine generator system under network voltage unbalance conditions were analyzed. In order to restrain various pulsations, a coordination control strategy of rotor-side and gridside converters of a doubly fed induction generator (DFIG) was presented. That took the pulsations of electromagnetic torque, stator-side reactive power and total output power at double supply frequency as control aims, and calculated the required compensation voltages, then superimposes them on the reference voltages of the rotor-side and grid-side converter. Thus the pulsations could be restrained effectively. Finally, the proposed control scheme was implemented in MATLAB/Simulink on a 1.5 MW DFIG connected to a power network with unbalanced voltage. Results showed that the proposed control strategy could minimize pulsations of electromagnetic torque, stator-side reactive power pulsation and total output power.%分析了在电网电压不平衡情况下双馈风力发电系统的运行特性.在此基础上,提出了不平衡电网电压下双馈电机的转子侧与网侧变换器协调控制策略,即以电磁转矩、定子侧无功功率以及总输出功率的2倍频脉动量为控制目标,计算出所需的补偿电压,叠加到转子侧与网侧变换器的参考电压中,从而通过补偿控制作用实现对脉动量的抑制.在MATLAB/Simulink中对1.5 MW双馈感应电机(DFIG)接入电压不平衡的电网情况进行了仿真,验证了所提出的控制策略可以有效抑制双馈电机的电磁转矩、无功功率和总输出有功功率脉动.
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