摘要
在研究电网电压不对称对双馈感应发电机(DFIG)影响以及DFIG正、负序数学模型的基础上,分析了电网电压不对称条件下DFIG定子输出有功、无功功率和发电机电磁转矩的组成。针对电网电压不对称时负序电流对定子侧有功功率、无功功率、电磁转矩和直流侧电压的影响,提出电流正序分量跟踪控制策略,并在转子侧和网侧变换器的控制中对电网电压的正、负序分量分别处理。转子侧变流器采用正序电流跟踪的滞环控制,实现了电流的无差跟踪。网侧逆变器控制内环采用电流前馈控制,并控制负序电流为零,外环采用电压环稳定直流电压。仿真结果表明,在电网不对称故障时,这种控制策略可以消除负序电流对定子侧有功功率、无功功率、电磁转矩和直流侧电压的影响,实现不对称故障穿越。
Based on the effect of the asymmetric grid voltage on DFIG and the positive and negative sequence mathematical model of DFIG, this paper analyses the composition of output active and reactive power of the DFIG stator and the generator electromagnetic torque under asymmetrical grid-voltage condition. Considering the effect on stator side active and reactive power, electromagnetic torque, and DC side voltage caused by the negative sequence current, a current positive sequence component tracking Control strategy is proposed, and the positive and negative sequence components of grid voltage are processed separately both in the rotor side converter control and the grid side converter control. Hysteretic positive sequence current tracking control technology is applied to the rotor side converter, which achieves a eta＇rent non-poor tracking. Current feedforward control technology is introduced into the inner ring of grid side inverter control, which ensures that negative sequence current is zero, while the outer ring adopts voltage ring to stabilize DC link voltage. Finally, the control strategy is simulated, and the simulation results demonstrate that the control strategy can eliminate the effect of the negative sequence current and realizes the asymmetrical faults ride-through.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2011年第16期101-106,共6页
Power System Protection and Control
关键词
双馈感应电机
不对称故障
风力发电
对称分量法
故障穿越
doubly fed induction generator （DFIG）
asymmetrical faults
wind power
symmetrical components
fault ride through
