一种LCL型并网逆变器的复合阻抗重塑方法  

Composite impedance reshaping method for LCL-type grid-tied inverter

作　　者：谢文浩[1] 王建赜[1] 纪延超[1] 于继来[1] 谢光仁 XIE Wen-hao;WANG Jian-ze;JI Yan-chao;YU Ji-lai;XIE Guang-ren(School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001,China;;Zhejiang Zheneng Wenzhou Electric Power Plant Co.,Ltd,Wenzhou 325602,China)

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,哈尔滨150001 [2]浙江浙能温州发电有限公司,浙江温州325602

出　　处：《电机与控制学报》2018年第10期35-42,50,共9页Electric Machines and Control

基　　金：科技部国际科技合作计划资助项目(2010DFR70600)

摘　　要：LCL型并网逆变器高频谐波衰减能力强,但存在谐振问题,并且并网电流在电网低频谐波电压的扰动下发生严重畸变。建立LCL型并网逆变器的状态空间模型,通过状态反馈有源阻尼控制配置主导极点,对并网逆变器谐振频率的输出阻抗进行校正,引入阻尼比以抑制谐振峰。进一步地,为了抑制电网背景谐波电压对并网电流的扰动,提出一种谐波补偿方法,通过电压前馈函数与二阶Butterworth滤波器串联,重塑逆变器的中低频输出阻抗,同时提高了电压前馈控制对阻抗参数的鲁棒性。采用这种复合阻抗重塑方法时,逆变器的中低频输出阻抗可以增大10倍以上,仿真实验验证了所述方法的正确性和有效性。Inverters with LCL filters have excellent abilities of attenuating high frequency current harmonics.However,the resonance and distortion of injected currents by the background harmonic voltage(BHV)are two common challenges faced by LCL-type grid-tide inverter.State-feedback control reshaped the output impedance of inverter at resonant frequency by replacing poles.The resonance peak was suppressed with damping ratio being increased.Moreover,in order to resist the effects of the BHV,a harmonic compensating method with a feed-forward voltage compensator and a second order Butterworth filter was proposed.Thus,the output impedance of inverter was reshaped within the low and medium frequency region,as well as improvement in the robustness of feed-forward compensator.Based on the composite impedance reshaping method,the output impedance of inverter was increased to 10 times within the low and medium frequency region.Simulation experiments for a three-phase LCL-type grid-tied inverter verify the effectiveness of the proposed method.

关 键 词：并网逆变器 有源阻尼 谐波补偿 BUTTERWORTH滤波器 阻抗重塑 

分 类 号：TM46[电气工程—电器]