Research on Three-Phase Imbalance in Distribution Networks Considering Coordinated Photovoltaic Phase Switching and Flexible Load

doi:10.12096/j.2096-4528.pgt.24062

Abstract

Abstract:

Objectives Considering the impact of single-phase distributed photovoltaic integration into distribution networks, this study proposes a mitigation method for three-phase imbalance in low-voltage distribution station area by coordinating flexible load response with photovoltaic regulation. Methods The proposed mitigation method comprises a flexible load response mode and a photovoltaic regulation mode. The flexible load response mode has the optimization objectives of minimizing network losses and load regulation costs, while the photovoltaic regulation mode has the objective of minimizing the number of photovoltaic phase-switching operations. The particle swarm optimization algorithm with different encoding strategies is used to solve the two adjustment modes respectively. Finally, the proposed method is validated using a real low-voltage distribution station area in North China. Results The results show that the method reduces the number of photovoltaic phase-switching operations and load response regulation costs. In addition, by analyzing the influence of weighting coefficients on the objective function, a recommended range for these coefficients is provided. Conclusions The method effectively addresses three-phase imbalance violations and reduces mitigation costs.

Key words: power system, distributed photovoltaic, flexible load, low-voltage distribution network, three-phase imbalance, commutation switch, three-phase power flow, coordinated optimal operation

CLC Number:

TK 01

Shan GAO, Jie XING, Yinghao SHAN, Yi GU. Research on Three-Phase Imbalance in Distribution Networks Considering Coordinated Photovoltaic Phase Switching and Flexible Load[J]. Power Generation Technology, 2025, 46(4): 768-777.

Figures/Tables 8

References 37

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类型	治理方法	不平衡越限	不平衡度达标率/%	网损/(kW⋅h)	负荷调节成本/元	换相开关动作次数
晴天	初始状态	是	16.67	18.67	—	—
	负荷响应模式	是	70.83	17.34	15.17	—
	光伏调节模式	是	66.67	18.26	—	5
	联合调节模式	否	100	17.52	6.96	1
阴天	初始状态	是	16.67	19.44	—	—
	负荷响应模式	是	70.83	18.10	15.21	—
	光伏调节模式	是	33.33	17.27	—	6
	联合调节模式	否	100	18.36	10.01	1

类型	治理方法	不平衡越限	不平衡度达标率/%	网损/(kW⋅h)	负荷调节成本/元	换相开关动作次数
晴天	初始状态	是	16.67	18.67	—	—
	负荷响应模式	是	70.83	17.34	15.17	—
	光伏调节模式	是	66.67	18.26	—	5
	联合调节模式	否	100	17.52	6.96	1
阴天	初始状态	是	16.67	19.44	—	—
	负荷响应模式	是	70.83	18.10	15.21	—
	光伏调节模式	是	33.33	17.27	—	6
	联合调节模式	否	100	18.36	10.01	1

类型	柔性负荷响应模型	不平衡度达标率/%	不平衡度平均值/%	不平衡度最大越限值	网损/(kW⋅h)	柔性负荷调节成本/元
晴天	初始状态	16.67	32.74	53.95	18.67	—
	w₁=0.9	70.83	25.88	46.79	15.47	38.28
	w₁=0.7	70.83	28.76	48.44	17.17	17.47
	w₁=0.5	70.83	29.13	49.35	17.34	15.17
	w₁=0.3	70.83	29.44	51.71	17.47	13.20
	w₁=0.1	66.67	30.12	52.47	17.54	13.16
阴天	初始状态	16.67	30.73	46.95	19.44	—
	w₁=0.9	70.83	23.93	41.32	16.19	37.24
	w₁=0.7	70.83	26.84	42.81	17.84	17.95
	w₁=0.5	70.83	27.05	43.16	18.10	15.21
	w₁=0.3	70.83	27.62	44.63	18.22	14.13
	w₁=0.1	66.67	28.05	45.91	18.36	12.01

类型	柔性负荷响应模型	不平衡度达标率/%	不平衡度平均值/%	不平衡度最大越限值	网损/(kW⋅h)	柔性负荷调节成本/元
晴天	初始状态	16.67	32.74	53.95	18.67	—
	w₁=0.9	70.83	25.88	46.79	15.47	38.28
	w₁=0.7	70.83	28.76	48.44	17.17	17.47
	w₁=0.5	70.83	29.13	49.35	17.34	15.17
	w₁=0.3	70.83	29.44	51.71	17.47	13.20
	w₁=0.1	66.67	30.12	52.47	17.54	13.16
阴天	初始状态	16.67	30.73	46.95	19.44	—
	w₁=0.9	70.83	23.93	41.32	16.19	37.24
	w₁=0.7	70.83	26.84	42.81	17.84	17.95
	w₁=0.5	70.83	27.05	43.16	18.10	15.21
	w₁=0.3	70.83	27.62	44.63	18.22	14.13
	w₁=0.1	66.67	28.05	45.91	18.36	12.01