考虑定子侧暂态过程的双馈感应发电机转子电流解耦控制

摘要

Given that the ability of doubly-fed induction generator (DFIG) to sustain power grid low voltage is mostly restricted by the overcurrent capacity of the converter at rotor side, appropriate control rules to avoid serious rotor overcurrent is key to keep DFIG connected with grid safely during voltage dip and voltage recovery. In order to improve the dynamic characteristics of rotor current, decoupling control strategy based on the 5th order model is proposed. It eliminates the adverse effects for rotor current dynamics by feedforward compensation considering transient stator flux. The corresponding control parameter design method is proposed as well. Simulation results show that the proposed strategy can quickly track the rotor current reference and restrain overcurrent so as to enhance DFIG' s low voltage ride-through capability. The results also verify the validity and availability of decoupling control strategy. The proposed method can be used in the parametrical designing method of DFIG considering its dynamic characteristics.This work is supported by National Natural Science Foundation of China (No. 51077078), State Key Lab of Power System Special Funds (No. SKLD09M08) and State Grid Research Funds for Coordination of Generator and Power System.%转子侧变流器过载能力是制约双馈感应发电机(DFIG)低电压耐受能力的主要瓶颈,合理的转子电流控制策略是DFIG安全度过电压跌落与恢复期暂态过程的保障.为改善转子电流的动态特性,以DFIG的5阶模型为基础,研究了考虑定子侧磁链暂态的转子电流解耦控制模型,通过前馈补偿环节消除定子磁链暂态对转子电流动态的不利影响,提出了DFIG转子侧变流器控制参数的设计方法.仿真结果表明,提出的控制策略可使转子电流快速跟踪参考值的变化并抑制过电流,改善了DFIG对电网电压波动的耐受能力,验证了该解耦控制模型的正确性和有效性,为DFIG转子电流动态响应特性的参数化设计提供了依据.