不对称电网电压下双馈风力发电机的直接功率控制  

Direct Power Control on the DFIG Wind Turbine Under Unbalanced Grid Voltage Conditions

作　　者：郭晓明[1] 贺益康[1] 何奔腾[1] 胡家兵[1] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电力系统自动化》2008年第13期86-91,共6页Automation of Electric Power Systems

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA05Z419)~~

摘　　要：在研究双馈感应发电机(DFIG)数学模型的基础上,分析了不对称电网条件下DFIG定子输出瞬时有功、无功功率的组成。通过引入二倍电网频率陷波器,使定开关频率直接功率控制(CSF-DPC)可适用于不对称性故障穿越运行控制。此时各改进的CSF-DPC方法具备各自特性,即基于转子磁链DPC(RF-DPC)可迅速稳定磁链,缩短DFIG动态过程;基于转子电流DPC(RC-DPC)可抑制定、转子电流振荡;基于电磁转矩DPC(EMT-DPC)可减小电磁转矩的脉动。通过分析改进CSF-DPC参数不匹配带来的误差,进一步提高了控制的鲁棒性。与正、负序双dq的不对称运行控制策略相比,CSF-DPC方法无需计算负序分量和引入负序电流控制环,结构简单,动态性能好。Based on the mathematic model of DFIG, the paper analyses the composition of instantaneous active and reactive power from the stator under unbalanced grid-voltage conditions. By adding a second frequency notch filter, the constant switching frequency direct power control （CSF-DPC） can be used for the unbalanced fault ride through operation. In this case, each improved CSF-DPC method presents its own unique characteristic, i.e. the rotor-flux based DPC （RF-DPC） can stabilize the flux and Shorten the DFIG dynam!c process; the rotor-current based DPC （RC-DPC） can suppress the oscillations of stator and rotor current; and the electromagnetic torque based DPC （EMT-DPC） has the ability of reducing the torque oscillation. On the basis of analysis on the errors caused by the DFIG parameter mismatch, the control robustness of the improved CSF-DPC schemes is further improved. In contrast to the conventional control strategy that needs negative sequence components and feedback loop, the proposed new CSF-DPC has a simpler structure and better dynamic performance.

关 键 词：双馈感应发电机 直接功率控制 稳态误差 不对称性故障穿越 

分 类 号：TM315[电气工程—电机]