CAJ | 학술논문

采用LCL滤波器可以有效地滤除并网逆变器的开关频率次谐波,但是进网电流易产生谐振,闭环设计困难。加权平均的电流控制方案实现了降阶的系统闭环设计,较为简便,但是进网电流中存在依赖于非理想因素的欠阻尼共轭极点,影响谐振频率次谐波抑制效果,系统带宽受限。文中提出将有源阻尼控制同电流加权控制有机结合以克服上述问题。对比分析了电流加权控制、结合无源阻尼的电流加权控制及结合有源阻尼的电流加权控制的特性,对控制的鲁棒性进行了研究。研究表明,结合有源阻尼的电流加权控制可实现更优的鲁棒性,进一步改善了系统闭环控制特性,且设计简便。
채용LCL려파기가이유효지려제병망역변기적개관빈솔차해파,단시진망전류역산생해진,폐배설계곤난。가권평균적전류공제방안실현료강계적계통폐배설계,교위간편,단시진망전류중존재의뢰우비이상인소적흠조니공액겁점,영향해진빈솔차해파억제효과,계통대관수한。문중제출장유원조니공제동전류가권공제유궤결합이극복상술문제。대비분석료전류가권공제、결합무원조니적전류가권공제급결합유원조니적전류가권공제적특성,대공제적로봉성진행료연구。연구표명,결합유원조니적전류가권공제가실현경우적로봉성,진일보개선료계통폐배공제특성,차설계간편。
For grid-connected inverters,the switching frequency harmonics can be effectively attenuated through LCL filters,however,the grid current is easy to be resonated,which results in the difficulty in the system design.If the weighted average of the currents through two inductors is used for the feedback control,the high order control of LCL system is degraded to a low order one.In this way it is easy to obtain good system performance.However,there are still under-damped conjugate poles depending on the non-ideal factors in the grid current.The inhibitions of harmonics at the resonance frequencies are poor and the system bandwidth is limited.An idea of combining active damping and weighted current control together is proposed to overcome these difficulties.Besides,the control characteristics of the proposed method,including the robustness,are investigated and compared with those of the weighted current control with passive damping.The proposed control strategy can realize better robustness and further improve the system performance through a simple design procedure.