摘要
并联型有源电力滤波器能有效地抑制电网中的谐波电流,而其补偿精度取决于电流环控制器的设计。由于电流环参考和反馈电流由许多次谐波叠加而成且传统的比例积分控制器(PI控制器)带宽有限,因此控制器不能实现无静差输出。为此首先分析了传统单PI控制器在大容量有源电力滤波器应用中的局限性。然后提出了一种以T型滤波器(LCL滤波器)为控制对象的PI内环,重复控制器外环构成的双环复合控制策略用来改善输出电流波形,并给出了详细的设计方法和稳定性分析。该控制器对奇次、偶次谐波电流以及不平衡负载条件下的负序谐波电流均具有很高的补偿精度,且易于实现。仿真和实验结果证明了复合电流控制器在大容量有源电力滤波器应用中的有效性。
Shunt active power filters （SAPF） could restrain harmonic current in power grids effectively and their compensation precision relies heavily on the design of current loop controllers. Since the reference and feedback signal of the current controller are superimposed by different harmonic current and the bandwidth of conventional Proportion-Integral （ PI） controller is limited, this controller cannot control the output current without any steady error. Consequently, we firstly analyzed the limitation of conventional PI controller in the application of large capacity APF. Then put forward a double loop compound controller composed of a PI inner loop and repetitive controller external loop to meliorate the output current waveform with the control object of LCL filters, and presented a design method in detail. The controller can easily realize and acquire high compensation precision when it is used to inhibit odd harmonic, even harmonic current as well as negative sequence harmonic current created by unbalanced load. Finally, simulation and experimental results verify the compound controller gains extraordinary effects in large capacity APF.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2010年第8期2060-2067,共8页
High Voltage Engineering
基金
国家自然科学基金(50707030)
教育部新世纪人才资助计划(060512)~~
