基于虚拟同步发电机的微电网并离网安全控制策略

doi:10.12096/j.2096-4528.pgt.19151

摘要/Abstract

摘要：

微电网作为综合能源系统的一大分支，广泛用于分布式电源的就地消纳。而随着冷、热、气等逐渐引入，对微电网安全控制的要求也越来越高。针对微电网的孤岛和并网建模及两运行状态之间的过渡过程进行分析，提出了改进虚拟同步发电机（virtual synchronous generator，VSG）模型下的控制策略。通过引入合适的虚拟阻抗，有效模拟了同步电抗的特性，保证孤岛运行基本稳定的同时，使得并网至孤岛的切换在该模型下不需要添加额外的控制部分即可完成平滑过渡；针对孤岛至并网的切换，提出了改进型的预同步控制模型，该模型能快速准确地跟踪电网电压幅值、频率以及相位。最后，结合实际算例对所构造的模型在Matlab/Simulink环境下进行仿真，验证了所提模型的正确性及其优势。

关键词: 微电网, 无缝切换, 虚拟同步发电机(VSG), 虚拟阻抗, 改进预同步控制

Abstract:

As a major branch of integrated energy system, micro-grid is widely used in the local consumption of distributed generation. With the introduction of cold, heat and gas, the requirement of micro-grid security control is becoming higher and higher. The grid-connected and off-grid mode of micro-grid and the transition process between two operating states were analyzed, furthermore, a control strategy based on improved virtual synchronous generator (VSG) model was proposed. By using appropriate virtual impedance, the characteristics of synchronous reactance were effectively simulated, which ensured the stability of off-grid operation and makes the transition from grid-connected mode to off-grid mode smooth without adding additional control. An improved pre-synchronization control model was proposed for the switching from off-grid mode to grid-connected mode, which could accurately and quickly track the voltage amplitude, frequency and phase. Finally, the model was simulated in Matlab/Simulink environment with a practical example to verify the correctness and advantages of the proposed model.

Key words: micro-grid, seamless switch, virtual synchronous generator (VSG), virtual impedance, improved pre-synchronization control

中图分类号:

TK01
TM727

郭亦宗, 郭创新. 基于虚拟同步发电机的微电网并离网安全控制策略[J]. 发电技术, 2020, 41(6): 650-658.

Yizong GUO, Chuangxin GUO. Security Control Strategy of Micro-grid Between Grid-connected and Off-grid Based on Virtual Synchronous Generator[J]. Power Generation Technology, 2020, 41(6): 650-658.

图/表 15

图1 虚拟同步发电机与同步发电机的并网对比

Fig.1 Comparison of grid-connected between VSG and SG

图2 PCC点电压跟踪电网电压相量图

Fig.2 Phase diagram of PCC voltage tracing grid voltage

表1 系统仿真参数

Tab. 1 Simulation parameters of system

参数	数值
直流电压/V	800
电网线电压/V	$ 220\sqrt{3} $
开关频率/Hz	1 350
滤波电容/μF	30
滤波电感/mH	3.5
滤波电阻/Ω	0.01
等效线路电阻/Ω	0.892 9
等效线路电感/mH	16.58
转动惯量/(kg?m²)	0.5
阻尼系数	20
有功频率调节系数	10 000
无功电压调节系数	0.000 1

图3 孤岛切负荷仿真模型

Fig.3 Simulation model of load-shedding in off-grid state

图4 孤岛切负荷频率变化曲线

Fig.4 Frequency curve of load-shedding in off-grid state

图5 孤岛切负荷电压变化曲线

Fig.5 Voltage curve of load-shedding in off-grid state

图6 孤岛切负荷电流变化曲线

Fig.6 Current curve of load-shedding in off-grid state

图7 并网转孤岛仿真模型

Fig.7 Simulation model of grid-connected to off-grid state

图8 并网转孤岛频率变化曲线

Fig.8 Frequency curve of grid-connected to off-grid state

图9 并网转孤岛联络线电压、电流变化曲线

Fig.9 PCC voltage and current curves of grid-connected to off-grid state

图10 改进预同步控制仿真模型

Fig.10 Simulation model of improved pre-synchronization control

图11 切换开关子系统仿真模型

Fig.11 Simulation model of switching switch subsystem

图12 孤岛转并网频率变化曲线

Fig.12 Frequency curve of off-grid to grid-connected

图13 孤岛转并网联络线电压、电流变化曲线

Fig.13 PCC voltage and current curves of off-grid to grid-connected state

图14 孤岛转并网Uq变化曲线

Fig.14 Uq curve of off-grid to grid-connected state

参考文献 24

1	马丽梅, 史丹, 裴庆冰. 中国能源低碳转型(2015-2050):可再生能源发展与可行路径[J]. 中国人口·资源与环境, 2018, 28 (2): 8- 18.
	MA L M , SHI D , PEI Q B . Low-carbon transformation of China's energy in 2015-2050:renewable energy development and feasible path[J]. China Population, Resources and Environment, 2018, 28 (2): 8- 18.
2	陈炜, 艾欣, 吴涛, 等. 光伏并网发电系统对电网的影响研究综述[J]. 电力自动化设备, 2013, 33 (2): 26- 32.
	CHEN W , AI X , WU T , et al. Influence of grid-connected photovoltaic system on power network[J]. Electric Power Automation Equipment, 2013, 33 (2): 26- 32.
3	郭亦宗, 王楚通, 施云辉, 等. 区域综合能源系统电/热云储能综合优化配置[J]. 电网技术, 2020, 44 (5): 1611- 1621.
	GUO Y Z , WANG C T , SHI Y H , et al. Comprehensive optimization configuration of electric and thermal cloud energy storage in regional integrated energy system[J]. Power System Technology, 2020, 44 (5): 1611- 1621.
4	张国栋, 刘凯. 能源互联网背景下的微电网能量管理分析[J]. 发电技术, 2019, 40 (1): 17- 21.
	ZHANG G D , LIU K . Analysis of microgrid energy management under the background of energy internet[J]. Power Generation Technology, 2019, 40 (1): 17- 21.
5	孙亮, 张秀琦, 吕凌虹, 等. 含分布式电源的配电网电压控制策略研究[J]. 电网与清洁能源, 2018, 34 (10): 1- 5.
	SUN L , ZHANG X Q , LÜ L H , et al. Study on voltage control strategy for the distribution network with distributed generation[J]. Power System and Clean Energy, 2018, 34 (10): 1- 5.
6	郭亦宗, 冯斌, 岳铂雄, 等.负荷聚合商模式下考虑需求响应的超短期负荷预测[J/OL].电力系统自动化: 1-16[2020-09-10].http://kns.cnki.net/kcms/detail/32.1180.TP.20200907.1321.004.html.
	GUO Y Z, FENG B, YUE B X, et al.Ultra short-term load forecasting considering demand response in load aggregator mode[J/OL].Automation of Electric Power System: 1-16[2020-09-10].http://kns.cnki.net/kcms/detail/32.1180.TP.20200907.1321.004.html.
7	谢林枫, 王红星, 刘军成, 等. 基于电能质量约束的智能配电网分布式电源消纳能力研究[J]. 电网与清洁能源, 2020, 36 (4): 41- 47.
	XIE L F , WANG H X , LIU J C , et al. A study on the distributed generation accommodation capacity of the smart distribution network based on power quality constraints[J]. Power System and Clean Energy, 2020, 36 (4): 41- 47.
8	丁婧, 王欣, 郑淑文, 等. DG接入对微电网电流保护的影响[J]. 发电技术, 2019, 40 (1): 22- 27.
	DING J , WANG X , ZHENG S W , et al. The impact of DG access on microgrid current protection[J]. Power Generation Technology, 2019, 40 (1): 22- 27.
9	张宁, 周天睿, 段长刚, 等. 大规模风电场接入对电力系统调峰的影响[J]. 电网技术, 2010, 34 (1): 152- 158.
	ZHANG N , ZHOU T R , DUAN C G , et al. Impact of large-scale wind farm connecting with power grid on peak load regulation demand[J]. Power System Technology, 2010, 34 (1): 152- 158.
10	郑竞宏, 王燕廷, 李兴旺, 等. 微电网平滑切换控制方法及策略[J]. 电力系统自动化, 2011, 35 (18): 17- 24.
	ZHENG J H , WANG Y T , LI X W , et al. Control methods and strategies of micro-grid smooth switchover[J]. Automation of Electric Power System, 2011, 35 (18): 17- 24.
11	王武. 一种主从控制模式下微网主电源逆变器的控制策略[J]. 机电工程技术, 2017, 46 (1): 55- 58.
	WANG W . A control strategy for micro-grid master inverter based on master-slave configuration[J]. M&E Engineering Technology, 2017, 46 (1): 55- 58.
12	TAO R, JU R.An improved droop control strategy in islanded micro-grid[C]//Proceedings of the 20166th International Conference on Machinery, Materials, Environment, Biotechnology and Computer.2016: 1488-1493.
13	聂志强, 梁晖, 罗浩, 等. 基于非线性下垂控制的单模式微网并/离网无缝切换技术[J]. 电网技术, 2016, 40 (5): 1371- 1378.
	NIE Z Q , LIANG H , LUO H , et al. Single mode grid-connected/islanded microgrid seamless transition based on nonlinear droop control technology[J]. Power System Technology, 2016, 40 (5): 1371- 1378.
14	岳同耿日, 余向阳, 吕优, 等. 基于对等和主从综合控制的微电网平滑切换控制方法研究[J]. 电气应用, 2019, 38 (1): 78- 84.
	YUE T G R , YU X Y , LÜ Y , et al. Research on smooth switching control method of microgrid based on peer-to-peer and master-slave integrated control[J]. Electrotechnical Application, 2019, 38 (1): 78- 84.
15	赵建荣, 杨欣然, 王林, 等. 基于虚拟同步机的微网并离网无缝切换策略[J]. 电力电子技术, 2018, 52 (10): 5- 8.
	ZHAO J R , YANG X R , WANG L , et al. Seamless transfer strategy of micro-grid between grid-connected and of grid based on virtual synchronous generator[J]. Power Electronics, 2018, 52 (10): 5- 8.
16	胡平, 任俊道. 光伏并网逆变器的虚拟同步发电机控制策略[J]. 自动化与仪表, 2019, 34 (7): 22- 25.
	HU P , REN J D . Virtual synchronous generator control strategy for grid-connected inverters[J]. Automation & Instrumentation, 2019, 34 (7): 22- 25.
17	柴伦, 李岚, 李冰, 等. 基于改进虚拟同步发电机的预同步并网策略[J]. 可再生能源, 2019, 37 (7): 1015- 1020.
	CHAI L , LI L , LI B , et al. Strategy of pre-synchronized grid-connection based on improving virtual synchronous generator[J]. Renewable Energy Resources, 2019, 37 (7): 1015- 1020.
18	王鑫琪, 黄陈蓉, 张建德, 等. 基于虚拟同步发电机的微网逆变器控制策略分析[J]. 电工技术, 2019, (12): 45- 47.
	WANG X Q , HUANG C R , ZHANG J D , et al. Analysis of control strategy of microgrid inverter based on virtual synchronous generator[J]. Electric Engineering, 2019, (12): 45- 47.
19	胡实, 袁旭峰, 朱余林, 等. 微网运行模式无缝切换控制技术研究[J]. 电测与仪表, 2018, 55 (17): 56- 61.
	HU S , YUAN X F , ZHU Y L , et al. Research on seamless switching control technology of micro-grid operation mode[J]. Electrical Measurement and Instrumentation, 2018, 55 (17): 56- 61.
20	宋琼, 张辉. 转动惯量对虚拟同步发电机输出特性的影响分析[J]. 电力电子技术, 2018, 52 (9): 28- 30.
	SONG Q , ZHANG H . The impact of inertia on characteristics of virtual synchronous generator[J]. Power Electronics, 2018, 52 (9): 28- 30.
21	杨赟, 梅飞, 张宸宇, 等. 虚拟同步发电机转动惯量和阻尼系数协同自适应控制策略[J]. 电力自动化设备, 2019, 39 (3): 125- 131.
	YANG Y , MEI F , ZHANG C Y , et al. Cooperative adaptive control strategy of rotational inertia and damping coefficient for virtual synchronous generator[J]. Electric Power Automation Equipment, 2019, 39 (3): 125- 131.
22	孙运志, 张成相, 蒋德玉, 等. 基于虚拟阻抗的微电网功率控制研究[J]. 信息技术, 2019, 43 (7): 133- 136.
	SUN Y Z , ZHANG C X , JIANG D Y , et al. Study of the microgrid power control based on virtual impedance control[J]. Information Technology, 2019, 43 (7): 133- 136.
23	李维波, 徐聪, 许智豪, 等. 基于自适应虚拟阻抗的舰用逆变器并联策略[J]. 高电压技术, 2019, 45 (8): 2538- 2544.
	LI W B , XU C , XU Z H , et al. Inverter parallel control strategy based on variable virtual impedance[J]. High Voltage Engineering, 2019, 45 (8): 2538- 2544.
24	杨亮, 王聪, 吕志鹏, 等. 基于同步逆变器的预同步并网方式[J]. 电网技术, 2014, 38 (11): 3103- 3108.
	YANG L , WANG C , LÜ Z P , et al. The method of pre-synchronized grid-connection of synchronverter[J]. Power System Technology, 2014, 38 (11): 3103- 3108.

[1]	杨捷, 孙哲, 苏辛一, 鲁刚, 元博. 考虑振荡型功率的直流微电网储能系统无互联通信网络的多目标功率分配方法[J]. 发电技术, 2024, 45(2): 341-352.
[2]	霍龙, 张誉宝, 陈欣. 人工智能在分布式储能技术中的应用[J]. 发电技术, 2022, 43(5): 707-717.
[3]	卢昕, 陈众励, 李辉. 基于自抗扰控制的直流微电网双向Buck-Boost变换器控制策略研究[J]. 发电技术, 2021, 42(2): 193-200.
[4]	陆永耕, 李建刚, 黄禹铭, 李柏玉. 高渗透率分布式电源控制方法[J]. 发电技术, 2021, 42(1): 103-114.
[5]	赵海川, 芦彦东, 郑浩康, 邢作霞. 低压微网中小型直驱永磁风电机组低电压穿越技术研究[J]. 发电技术, 2020, 41(6): 659-666.
[6]	钱梦然,李辉,刘新秀. 基于自抗扰控制的微电网三相不平衡问题研究[J]. 发电技术, 2020, 41(2): 160-166.
[7]	孙黎霞,鞠平,白景涛,刘甜甜. 计及蓄电池寿命的冷热电联供型微电网多目标经济优化运行[J]. 发电技术, 2020, 41(1): 64-72.
[8]	朱辉,吕红芳,阳晓明. 基于多代理系统的微电网多目标优化调度[J]. 发电技术, 2019, 40(6): 527-534.
[9]	范丽霞,蔡瑞强,张欢畅,魏远,田恬,胡斌. 电压型虚拟同步发电机控制策略下的双馈风电机组阻抗及次同步振荡特性[J]. 发电技术, 2019, 40(5): 434-439.
[10]	刘忠强,刘忠富. 基于本地检测法的微电网孤岛检测方法研究[J]. 发电技术, 2019, 40(2): 122-127.
[11]	丁婧,王欣,郑淑文,陈宇,孙仕奇. DG接入对微电网电流保护的影响[J]. 发电技术, 2019, 40(1): 22-27.
[12]	张国栋,刘凯. 能源互联网背景下的微电网能量管理分析[J]. 发电技术, 2019, 40(1): 17-21.
[13]	何力,吕红芳. 考虑经济性的多微电网优化调度研究[J]. 发电技术, 2018, 39(5): 397-404.