不平衡负载下双定子无刷双馈发电机独立运行控制策略

Control Strategy of Stand-Alone Brushless Doubly-Fed Induction Generator System under Unbalanced Loads

该文以运行于独立发电工况下的一种新型双定子无刷双馈发电机为研究对象。为解决三相负载不均衡情形下负载对公共节点电压质量的影响,提出了一种基于控制绕组变换器的负序电压抑制策略。该策略在负同步坐标系下对负序电压分量进行提取和补偿控制,再经过坐标变换加入到正同步坐标系下进行统一的正、负序电流闭环调节。由于控制量中二倍频分量的存在,该方法采用比例积分谐振控制器(PIR)替代传统的比例积分(PI)环节,克服了增益不足的问题。建立了双定子无刷双馈独立发电系统的实验平台,实验结果验证了所提控制策略的可行性和有效性。

This paper focuses on a dual-stator brushless doubly fed induction generator-based stand-alone generation system （DSBDFIG-SA-GS）. For the purpose of compensating negative sequence components that exist in the generated voltage under unbalanced loads, a novel control strategy based on the control winding converter is presented. The proposed strategy extracts and regulates the negative sequence in the negative rotating frame. Afterwards, the current controller is implemented in a single positive rotating reference frame, therefore the controller can directly regulate both the positive and negative sequence components. A proportional-integral-resonant （PIR） current control scheme is employed as a replacement of the conventional proportional-integral （PI） controller for the existence of ac components in current reference value. Finally, experimental platform of the DSBDFIG is established and experimental results are presented to validate the effectiveness and robustness of the proposed control method.