PI控制参数对双馈风电机组短路电流特性的影响分析

Influence of PI control parameters on short circuit current characteristics of DFIG

在机端电压跌落程度不深的情况下,双馈风电机组(DFIG)不投入撬棒,而是通过改变转子侧控制策略的方法抑制转子侧过电流,此时定子短路电流中会产生衰减暂态电流分量,而DFIG控制系统的PI参数是影响该衰减暂态电流分量的主要因素。以机端发生对称故障的情况为例,针对机端电压跌落程度不深时撬棒保护未投入的情况,推导了DFIG短路电流的表达式,从理论上分析了PI参数对其短路电流特性的影响,并且辅以PSCAD仿真验证分析了在机端电压跌落轻微的情况下DFIG的短路电流特性。

During a mild terminal voltage dip, DFIG（Doubly Fed Induction Generator） may not put the Crowbar protection into operation hut change its rotor-side control strategy to suppress the rotor-side overcurrent,which may induce decaying transient components in the short circuit current of stator. The PI parameters of DFIG control system are the main influencing factors of the induced transient components. A symmetrical fault of stator terminal,when the Crowbar protection is not put into operation during the mild terminal voltage dip,is taken as an example to deduce the DFIG short circuit current expression for theoretically analyzing the influence of PI parameters of rotor-side converter control system on the characteristics of DFIG short circuitcurrent,which are further verified by the PSCAD simulation.