电网支持型变流器输出建模、控制及稳定性分析  

Analysis of modeling,control and stability for grid-supporting power converters

作　　者：黄鹭鹭 高波 孙丽敬 HUANG Lulu;GAO Bo;SUN Lijing(State Grid Shanghai Energy Interconnection Research Institute Co.,Ltd.,Shanghai 201210,China;China Electric Power Research Institute Co.,Ltd.,Beijing 100192,China)

机构地区：[1]国网上海能源互联网研究院有限公司,上海201210 [2]中国电力科学研究院有限公司,北京100192

出　　处：《电力系统保护与控制》2022年第4期44-53,共10页Power System Protection and Control

基　　金：国家电网总部科技项目:面向交-直流配电网柔性互联的拓扑及关键控制技术(SGAH0000KJJS2000680)。

摘　　要：电网支持型变流器逐渐取代传统同步机电源是构建新型电力系统的必然趋势。电网支持型变流器采用双环控制的目的和物理意义尚未形成统一结论。首先,为解释双环控制中电流内环的本质,由电流内环的离散根轨迹曲线分析电流内环的阻尼特性,从虚拟阻抗的角度分析其物理意义。其次,为快速准确获得双环控制器参数,避免反复迭代,考虑数字控制系统采样、计算和PWM调制带来的延时,内环采用比例控制器调整阻尼特性。根据最优阻尼确定电流控制器的比例参数,根据滤波器谐振频率处闭环输出增益的要求和各次谐波的补偿角度确定电压控制器的参数。最后,仿真和实验结果验证了理论分析的有效性。Grid-supporting power converters are gradually replacing the traditional synchronous machine power supply.It is an inevitable trend as new power systems are built.There is not a consensus on the purpose and physical meaning of dual-loop control for grid-supporting power converters.First,in order to elaborate the essence of inner current loop in dual-loop control,this paper analyzes damping characteristics of the current inner loop from the discrete root locus curve and addresses physical meaning from the perspective of virtual impedance.Secondly,to obtain the parameters of dual-loop controller quickly and accurately,avoiding iterations,and considering the delay caused by the sampling,calculation and PWM modulation of the digital control system,the inner loop uses a proportional controller to adjust the damping characteristics of the current inner loop.The proportional coefficient of the current controller is obtained from the optimal damping.The coefficients of the voltage controller are determined by the requirements of the closed-loop output gain at the filter resonance frequency and compensating offset angles of harmonics.Finally,simulations and experimental results have verified the effectiveness of theoretical analysis.

关 键 词：电网支持型逆变器 离散域 虚拟阻抗 双环控制 比例控制器 比例谐振控制器 

分 类 号：TM46[电气工程—电器]