微电网并联VSG环流抑制与功率精确分配控制策略研究

doi:10.11985/2023.03.039

摘要/Abstract

摘要：

针对并联虚拟同步机各自距离负荷的线路长短不一致，导致并联VSG之间将产生功率环流的问题，提出一种基于自适应虚拟阻抗并联虚拟同步机控制策略。首先，建立2台并联虚拟同步机基本结构框图。对其功率环流进行分析，为了抑制功率环流实现无功功率精确分配，设计自适应虚拟阻抗单元。其次，对2台并联虚拟同步机控制系统进行参数整定设计。最后，建立自适应虚拟阻抗并联虚拟同步机控制系统仿真模型。分别对未引入自适应虚拟阻抗并联虚拟同步机和引入自适应虚拟阻抗并联虚拟同步机控制进行仿真对比，并在孤岛运行和并网运行有功和无功额定容量分别为1∶1和2∶1的条件下进行仿真算例分析。仿真结果表明，基于自适应虚拟阻抗并联VSG能够很好地抑制功率环流，对系统功率能够实现精确分配。

关键词: 微电网, 虚拟同步机, 自适应, 功率环流

Abstract:

In order to solve the problem of power circulation between parallel VSGs due to the different length of lines between parallel virtual synchronous generators and loads, a control strategy of parallel virtual synchronous generators based on adaptive virtual impedance is proposed in this paper. Firstly, the basic structure block diagram of two parallel virtual synchronous generators is established, and the power circulation is analyzed. In order to suppress the power circulation, an adaptive virtual impedance unit is designed. Secondly, the parameter tuning design of the control system of two parallel virtual synchronous generators is carried out. Finally, the system simulation model of parallel VSG are established without adaptive virtual impedance and with adaptive virtual impedance respectively, and the simulation example analysis is carried out under the condition that the rated capacity(1:1 and 2:1) of active power and reactive power of island operation and grid operation respectively. The simulation results show that the parallel VSG based on adaptive virtual impedance can well suppress the power circulation and achieve accurate power distribution.

Key words: Microgrid, virtual synchronous generator, self-adaption, power circulation

中图分类号:

TM73

张常友, 朱作滨, 孙树敏, 王绎舜. 微电网并联VSG环流抑制与功率精确分配控制策略研究[J]. 电气工程学报, 2023, 18(3): 369-376.

ZHANG Changyou, ZHU Zuobin, SUN Shumin, WANG Yishun. Research on Control Strategy of Circulating Current Suppression and Accurate Power Distribution of Parallel VSG in Microgrid[J]. Journal of Electrical Engineering, 2023, 18(3): 369-376.

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参数	数值	参数	数值
P_n/kW	10	Q_n/kVar	20
V_dc/V	800	C/F	15×10^-6
L/H	0.003	U_n/V	311
Z₁/Ω	1.92+j0.4	Z₂/Ω	2.84+j0.8
k_Qu1	1×10^-4	k_Qu2	5×10^-5
k_pf1	2×10^-4	k_pf2	1×10^-4