双馈异步风力发电机无差拍直接功率控制及延时补偿

Dead-Beat Direct Power Control of Doubly Fed Induction Generators with Delay Compensation

针对双馈异步风力发电机(DFIG),传统基于开关表的直接功率控制策略(LUT-DPC)存在功率波动较大、开关频率不固定、电流谐波丰富等问题。本文提出一种结构和原理简单的无差拍直接功率控制策略(DB-DPC),将无差拍控制原理与空间矢量脉宽调制(SVM)技术及DPC策略相结合,无需旋转坐标变换,在消除瞬时有功及无功功率静差、减少谐波含量的同时获得了固定的开关频率。采用了"两步预测"方式对实际系统中的采样周期延时进行补偿,进一步提高了系统控制精度及动态响应速度。仿真和实验结果验证了该DB-DPC策略及延时补偿方案在DFIG中应用的正确性和可行性。

This paper presents a dead-beat direct power control（DB-DPC） strategy for doubly fed induction generators（DFIGs） in order to overcome the power ripples, current harmonics and inconstant switching frequency of the conventional look-up table direct power control（LUT-DPC）. The proposed DPC strategy employs a simple dead-beat control scheme so as to eliminate the instantaneous errors of active and reactive powers without involving any rotating coordinate transformations. A fixed switching frequency can be achieved by using the space vector modulation（SVM） technique. Furthermore, in order to alleviate the power oscillation, improve the dynamic performance and reduce the steady state errors of active and reactive powers, a two-step prediction compensation method is proposed in practical systems for both power errors and angular shifts caused by sampling delays. The effectiveness and fesibility of the proposed DB-DPC and the delay compensation strategy in the DFIG system are verified by both the simulation and experimental results.