多复杂系数滤波器在风电并网变流器中的应用

Application of Multi-complex Coefficient Filter in Wind Power Grid-connected Converter

同步信号对风电三相并网变流器的运行起着非常重要的作用,如何在电网电压畸变、频率波动或不平衡条件下快速、精确地提取出基波正序电压分量是同步信号检测面临的挑战。首先介绍了同步信号检测的滤波技术,当电网电压严重畸变和严重不平衡时,这些技术需要在精确度和动态响应之间进行平衡。然后提出了基于MCCF(多复杂系数滤波器)的同步信号检测技术,在非理想电网电压条件下不仅可以精确、快速地提取出正、负序电压分量,而且实现了对谐波分量的精确估算,从而在有源滤波器选择性补偿方面具有很大的应用潜能。另外,MCCF在锁相环、谐波分量提取、电能质量监测和孤岛检测技术中具有结构简单、灵活性强的特点。最后通过在MATLAB中建模仿真,验证了基于MCCF的同步信号检测技术的有效性。

Synchronization signal is crucial to the operation of the three-phase grid-connected converter of wind power. A challenge in synchronization signal detection is how to fast and precisely extract the fundamental positive sequence voltage component under the distorted grid voltage and frequency fluctuation and unbalance. The paper introduces the filter techniques of synchronization signal detection, which need to strike a balance between precision and dynamic response under severe grid voltage distortion and unbalance. Besides, the paper proposes a synchronization signal detection technique based on MCCF(multi-complex coefficient filter), which, under unfavourable gird voltage, can fast extract positive and negative sequence voltage component and calculate harmonic components and therefore has great application potential in selective compensation of active filter. MCCF is characterized by its simple structure and flexibility in the phase-locked loop, harmonic component extraction, power quality monitoring and islanding detection technology. Modelling and simulations in MATLAB confirm the effectiveness of the MCCF-based synchronization signal detection technology.