采用比例谐振调节器的三相VSC控制系统稳定性研究  

Stability Study of Control System Based on PR Regulator for Three-phase VSC

作　　者：孙强[1,2] 王莎莎 魏克新[1,2] 高成海[1] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]天津市复杂系统控制理论及应用重点实验室,天津300384 [3]北京新能源汽车股份有限公司,北京102606

出　　处：《高电压技术》2016年第10期3147-3155,共9页High Voltage Engineering

基　　金：国家自然科学基金(50977063);国家高技术研究发展计划(863计划)(2013BAG01B00)~~

摘　　要：在介绍基于LCL电容电流反馈有源阻尼算法的电流环控制策略基础上,在αβ静止坐标系下构建了三相变流器开关周期平均数学模型。为了消除系统交变量瞬态反馈时传统PI调节器难以达到无稳态静差输出,电流内环采用比例谐振控制器以实现无静差跟踪正弦电流基波给定,外环则采用基于瞬时功率模型的准直接功率控制环。通过闭环传递函数频域响应特性深入探讨了电流内环比例谐振控制器及有源阻尼LCL拓扑各参数对系统鲁棒性的影响。引入Delta算子以代替Tustin变换对控制器进行离散化实现,保证了离散结果较为接近于时域连续值,解决了z变换导致的数值计算不稳现象,从而实现了理想的电流正弦信号输出。仿真与实验结果验证了所提出的控制策略能够有效降低网侧输入电流谐波畸变率,实现单位功率因数运行,使得电能质量和系统瞬态响应得以明显改善。Based on the current control strategy with capacitor-current-feedback active damping, the average switching model for PWM converter was built under αβ stationary frame. In order to eliminate the static error of alternating current that PI controller could not achieve, the quasi PR regulator of inner current loop was employed to track the given fundamental sinusoidal current. Then the quasi DPC algorithm of out loop based on instantaneous power theory was presented. The influences of PR controller and parameters in LCL active damping loop on system＇s robustness were studied by the means of frequency response characteristics. Instead of Tustin discretization, Delta operator was introduced to avoid instability issues of z domain transformation and to obtain well sinusoidal current output approximating to continuous model. The simulation and experimental results verify that the proposed control strategy can achieve unity power factor with low total harmonic distortion, and the system＇s power quality and dynamic performance are also well improved.

关 键 词：开关周期平均模型 比例谐振 有源阻尼 DELTA算子 鲁棒性 

分 类 号：TM46[电气工程—电器]