采用三电平拓扑结构的广义有源电力滤波器

摘要

提出一种采用三电平拓扑结构的广义有源电力滤波器(GAPF),其具有更高的等效开关频率和电压等级,适合在高压大功率领域中应用.详述了三电平GAPF的拓扑结构、工作原理和控制方法.为克服特定消谐技术实时性差且不利于中性点电压的调节等缺点,采用空间矢量调制技术,并提出一种定量计算小矢量占空比的方法,可实现三电平逆变器直流侧电容电压的精确平衡.仿真结果证明三电平GAPF可以有效地实现无功补偿、谐波抑制、负序滤波等功能,并大幅降低对网侧滤波电抗容量的要求.%A GAPF(Generalized Active Power Filter) based on three-level inverter is proposed,which has higher equivalent switching frequency and voltage level,suitable for high power applications. Its topology, operating principle and control method are discussed. Because the selective harmonic elimination technique is poor in real-time performance and neutral-point voltage adjustment, the space vector modulation technique is adopted. In order to precisely balance the DC-side capacitor voltages of three-level inverter,a method is proposed to quantitatively calculate the duty cycle of small vector. Simulative results show that, three-level GAPF can effectively realize the functions of reactive power compensation, harmonics suppression and negative sequence filtering and greatly reduce the capacity of grid-side filtering reactor.