Research on a PV-energy storage system with integration of grid-connection and disconnection modes based on low-pressure DC distribution network

doi:10.3969/j.issn.1674-1951.2021.04.010

Abstract

Abstract:

In order to keep the stability of the inverters connected to a weak grid,a PV-energy storage system with integration of grid-connection and disconnection modes based on low-voltage DC distribution network is proposed.The system includes PV modules,common DC bus,energy storage system,low-voltage DC distribution network,AC/DC loads and multiple power converters.According to the three-level energy management strategy for PV generation,energy storage and distribution network,different power converter control strategies were taken.The system has four working modes：isolated operation with PV power generation,grid-connected operation with PV power generation,isolated operation with battery power supply,grid-connected operation with grid power supply.Each working condition was simulated in Matlab/Simulink.The results verify the correctness of the proposed system,which provides a theoretical reference for the practical application of the PV-energy storage system with integration of grid-connection and disconnection modes based on low-voltage DC distribution network.

Key words: DC grid-connection, PV-energy storage system, integration of grid-connection and disconnection, energy management, low-voltage DC distribution network, power converters, energy storage system, harmonic oscillation

CLC Number:

TK02

LIU Jindou, CHENG Jie, YU Gaowei. Research on a PV-energy storage system with integration of grid-connection and disconnection modes based on low-pressure DC distribution network[J]. Huadian Technology, 2021, 43(4): 63-70.

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References 13

[1]	梁星. 并离网一体光伏发电系统研究与设计[D]. 上海:上海交通大学, 2014.
[2]	张兴, 张崇巍. PWM整流器及其控制[M]. 北京: 机械工业出版社, 2012.
[3]	桑顺, 高宁, 蔡旭, 等. 电池储能变换器弱电网运行控制与稳定性研究[J]. 中国电机工程学报, 2017,37(1):54-64.
	SANG Shun, GAO Ning, CAI Xu, et al. Operation control and stability study of converters for battery energy storage under weak grid conditions[J]. Proceedings of the CSEE, 2017,37(1):54-64.
[4]	AGORRETA J L, BORREGA M, LÓPEZ J, et al. Modeling and control of N-paralleled grid-connected inverters with LCL filter coupled due to grid impedance in PV plants[J]. IEEE Transactions on Power Electronics, 2011,26(3):770-785.
[5]	许德志, 汪飞, 毛华龙, 等. 多并网逆变器与电网的谐波交互建模与分析[J]. 中国电机工程学报, 2013,33(12):64-71,187.
	XU Dezhi, WANG Fei, MAO Hualong, et al. Modeling and analysis of harmonic interaction between multiple grid-connected inverters and the utility grid[J]. Proceedings of the CSEE, 2013,33(12):64-71,187.
[6]	ROCABERT J, LUNA A, BLAABJERG F, et al. Control of power converters in AC microgrids[J]. IEEE Transactions on Power Electronics, 2012,27(11):4734-4749. doi: 10.1109/TPEL.2012.2199334
[7]	DRIESEN J, VISSCHER K. Virtual synchronous generators[C]//2008 IEEE Power and Energy Society General Meeting. IEEE,Pittsburgh,PA,USA, 2008: 1040-1560.
[8]	宋强, 赵彪, 刘文华, 等. 智能直流配电网研究综述[J]. 中国电机工程学报, 2013,33(25):9-19,5.
	SONG Qiang, ZHAO Biao, LIU Biao, Wenhua Biao, et al. An overview of research on smart DC distribution power network[J]. Proceedings of the CSEE, 2013,33(25):9-19,5.
[9]	段双明, 郭阳, 任俊, 等. 含分布式电源的低压直流配电网研究综述[J]. 东北电力大学学报, 2015,35(6):1-7.
	DUAN Shuangming, GUO Yang, REN Jun, et al. Review of DG integrated low voltage DC distribution network[J]. Journal of Northeast Electric Power University, 2015,35(6):1-7.
[10]	谢少军, 肖华锋, 罗运虎. 直流楼宇技术初议[J]. 电工技术学报, 2012,27(1):107-113.
	XIE Shaojun, XIAO Huafeng, LUO Yunhu. On DC-building technology[J]. Transactions of China Electrotechnical Society, 2012,27(1):107-113.
[11]	徐德鸿. 电力电子系统建模及控制[M]. 北京: 机械工业出版社, 2006.
[12]	李莎. 直流配电网电压等级序列研究[D]. 杭州:浙江大学, 2017.
[13]	ROSEKEIT M, DONCKER R W D. Smoothing power ripple in single phase chargers at minimized DC-link capacitance[C]//8th International Conference on Power Electronics- ECCE Asia. IEEE,Jeju,Korea, 2011: 2699-2703.

项目	工况1	工况2	工况3	工况4
光伏侧	CV模式	MPPT模式	关闭或MPPT模式	关闭
电池侧	关闭或Buck模式	CV模式	Boost模式	Buck模式
并网侧	关闭	Boost模式	关闭	Buck模式
直流负载侧	Buck模式	Buck模式	Buck模式	Buck模式
全桥逆变器	逆变模式	逆变模式	逆变模式	逆变模式

项目		参数值	项目		参数值	项目		参数值	项目		参数值	项目		参数值
光伏侧	C_PV/μF	4	电池侧	C_bat/μF	60	并网侧	C_grid/μF	100	直流负载侧	C_dcr/μF	50	全桥逆变侧	L_A/mH	5
	L₁/mH	2		L₂/mH	2		L₃/mH	2		L₄/mH	2		L_B/mH	5
	f_s/kHz	20		f_s/kHz	20		R/Ω	1		R_dc/Ω	100		R_ac/Ω	31.1
	V_mp/V	261		V_bat/V	295~332		V_grid/V	600		V_dcr/V	240		V_ac/V	220
	P_n/W	5 000		P_n/W	5 000					P_dcr/W	576		P_dc/W	1 555