基于混合势函数的直流微电网群稳定性分析

doi:10.16180/j.cnki.issn1007-7820.2022.01.011

摘要/Abstract

摘要：

直流微电网群中的恒功率负载呈现负阻抗特性,会对直流微电网群稳定性造成不利影响,因此需对直流微网群稳定性功率界限进行分析。针对此类问题,文中采用混合势函数,对含恒功率负载的直流微电网群进行大信号稳定性分析。根据子微网间连接的DC-DC变换器特性,将直流微电网群等效成子微网与受控电流源并联的形式,以此建立直流微电网群大信号等效电路图。由混合势函数理论推导出直流微电网群大信号稳定性判据,并依据判据进行稳定性分析。通过MATLAB/Simulink进行验证,证明直流微电网群经恒功率负载突增后,若满足稳定性判据,则该直流微网群可保持稳定运行。

关键词: 直流微电网群, DC-DC变换器等效模型, 微网大信号等效模型, 混合势函数模型, 混合势函数判据, 稳定性判据分析, 恒功率负载, 稳定性仿真分析

Abstract:

The constant power load in DC microgrid group presents negative impedance characteristics, which will adversely affect the stability of DC microgrid group. Therefore, it is necessary to analyze the stability power limit of DC microgrid group. In order to solve the problem, this study uses a mixed potential function to analyze the large-signal stability of a DC microgrid group with a constant power load. According to the characteristics of the DC-DC converters connected between the sub-microgrids, the DC microgrid group is equivalent to a sub-microgrid and a controlled current source in parallel, so as to establish the large signal equivalent circuit diagram of the DC microgrid group. The large-signal stability criterion of the DC microgrid group is derived from the mixed potential function theory, and the stability analysis is carried out according to the criterion. Verification by MATLAB/Simulink proves that the DC microgrid group can maintain stable operation if it meets the stability criterion after the constant power load increases.

Key words: DC microgrid group, DC-DC converter equivalent model, microgrid large signal equivalent model, mixed potential function model, mixed potential function criterion, stability criterion analysis, constant power load, stability simulation analysis

中图分类号:

TP274

王玉梅,张子寒,王浩. 基于混合势函数的直流微电网群稳定性分析[J]. 电子科技, 2022, 35(1): 66-72.

WANG Yumei,ZHANG Zihan,WANG Hao. Large-Disturbance Stability Analysis of DC Microgrid Based on Mixed Potential Function[J]. Electronic Science and Technology, 2022, 35(1): 66-72.

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微网1参数	数值	微网2参数	数值
母线电压u_DC1	391 V	母线电压u_DC2	364 V
等效内阻R₁	0.04 Ω	等效内阻R₂	0.03 Ω
等效电感L₁	1 000 μH	等效电感L₂	900 μH
滤波电容C₁	3 000 μF	滤波电容C₂	2 700 μF
光伏功率	4 000 W	光伏功率	3 500 W
负载功率	11 000 W	负载功率	10 500 W
大容量负载阶跃功率	7 000 W	大容量负载阶跃功率	6 000 W
储能功率P_E	6 270.36 W

	ΔP_CPL1	ΔP_CPL2	P_CPL1+ P_CPL2	判据式(21)
情况A	7 000 W	0 W	22 000 W	满足
情况B	0 W	6 000 W	21 000 W	满足
情况C	4 000 W	3 500 W	22 500 W	满足
情况D	7 000 W	6 000 W	28 000 W	不满足