面向不平衡电网的改进型电压支撑方法研究

曹晓庆; 李特; 李林; 陈迪; 周正旭; 时晓洁

PDF(4231 KB)

电力建设 ›› 2025

面向不平衡电网的改进型电压支撑方法研究

曹晓庆¹, 李特², 李林¹, 陈迪¹, 周正旭¹, 时晓洁²

作者信息 +

Research on improved voltage support method for unbalanced grid condition

CAO Xiaoqing¹, LI Te², LI Lin¹, CHEN Di¹, ZHOU Zhengxu¹, SHI Xiaojie²

Author information +

文章历史 +

摘要

【目的】随着大规模分布式光伏接入,潮流反送所引起的电压越限问题给电力系统的安全稳定运行带来了严峻挑战。为解决该问题,国内外均规定光伏需具有电压-无功等支撑功能,即依据电压偏差进行主动无功/有功调节。然而,该类规定通常仅考虑平衡电压场景,如何保证不平衡电压下的调压性能鲜有研究。因此,文章以电压-无功功率控制(Volt-Var control, VVC)为例,分析了电压不平衡度对光伏逆变器无功功率调节性能的影响,并提出了一种以三相电压偏差最小为目标的改进型电压支撑控制方法。【方法】基于瞬时功率理论分析了电压不平衡度与有功、无功功率间的数学关系,证明了无功功率的电压调节作用及电压偏差最小值点的存在;然后以三相电压总偏差为指标,计算了电压偏差最小时对应的正序电压及无功功率,进而利用该点、电压偏差限值及光伏无功容量对电压支撑控制曲线进行了动态调节。【结果】Matlab/Simulink仿真结果表明所提改进型电压支撑控制方法在保证三相电压不越限的同时实现了最小无功输出下的三相电压与标称电压偏差最低,完成不平衡场景下三相电压的经济、高效调节。【结论】所提控制策略为传统VVC控制与负序电流/功率控制的有效协同,在辐照度、温度等变化引起光伏出力改变或电压不平衡度变化时仍可维持三相电压运行在并网标准限值范围内,显著提升了传统VVC控制功能的适应性。

Abstract

[Objective] With the integration of large-scale distributed photovoltaics, issues like reverse power flow and over-voltage arise, posing challenges to the safe and stable operation of the power system. To address this issue, both domestically and internationally, regulations mandate that PV systems must have grid support capabilities, such as voltage-reactive control, i.e., they actively regulate their reactive power based on voltage deviations. However, such regulations are typically designed for balanced voltage scenarios, and unbalanced voltage conditions are rarely considered. Therefore, taking the voltage-reactive power control(Volt-Var control, VVC) as an example, this paper analyzes the influence of voltage imbalance on their reactive power output, and proposes an improved voltage support control method aiming at a minimal three-phase voltage deviation. [Methods] Based on the instantaneous power theory, the mathematical relationship between voltage imbalance and active/reactive power is derived, demonstrating the voltage regulation effect of reactive power and the existence of the minimum voltage point. Then, with the three-phase voltage deviation as an index, the positive sequence voltage and reactive power corresponding to such point are calculated, and dynamic adjustments to the voltage support control curve are made using this point, voltage limits, and reactive power capacity of PV inverters. [Results] Matlab/Simulink simulation results demonstrate that the proposed improved voltage support control method ensures three-phase voltages remain within limits while achieving minimal deviation from the nominal voltage under the lowest reactive power output, accomplishing economical and efficient regulation of three-phase voltage in unbalanced scenarios. [Conclusions] The proposed control strategy effectively coordinates traditional VVC control with negative-sequence current/power control. It maintains three-phase voltages within grid-connected standard limits despite changes in irradiance, temperature, or other factors causing photovoltaic power fluctuations or voltage-unbalance variations, significantly enhancing the adaptability of conventional VVC control functions.

导出引用

曹晓庆, 李特, 李林, 陈迪, 周正旭, 时晓洁. 面向不平衡电网的改进型电压支撑方法研究[J]. 电力建设. 2025

CAO Xiaoqing, LI Te, LI Lin, CHEN Di, ZHOU Zhengxu, SHI Xiaojie. Research on improved voltage support method for unbalanced grid condition[J]. Electric Power Construction. 2025

参考文献

[1] 林玉鑫, 张京业. 海上风电的发展现状与前景展望[J]. 分布式能源, 2023, 8(2): 1-10.LIN Yuxin, ZHANG Jingye. Development status and prospect of offshore wind power[J]. Distributed Energy, 2023, 8(2): 1-10.
[2] 谢芮芮,徐铭铭,陈薇如,等. 配电网新能源承载力多目标决策评估方法[J]. 供用电, 2024, 41(07): 99-108.
Xie, Ruirui, Xu, Mingming, Chen, Weiru, et al.Multi-Objective Decision-Making Assessment Method for the Renewable Energy Carrying Capacity of Distribution Networks. Power Supply and Consumption, 2024, 41(07): 99-108.
[3] 于艾清,濮梦燕,王育飞,等. 基于改进鲸鱼算法的分布式电源规划方法[J]. 电测与仪表, 2024, 61(08): 63-69.
Yu Aiqing, Pu Mengyan, Wang Yufei, et al.Distributed Generation Planning Method Based on Improved Whale Optimization Algorithm[J]. Electrical Measurement & Instrumentation, 2024, 61(8): 63-69.
[4] 缪雨函,许寅,王颖. 面向恢复力提升的高比例分布式光伏接入配电网规划方法[J]. 山东电力技术, 2024, 51(08): 1-9.
Miao, Yuhan, Xu, Yin, Wang, Yin.Planning Method for High-Proportion Distributed Photovoltaic Integration in Distribution Networks Aimed at Resilience Improvement. Shandong Electric Power Technology, 2024, 51(08): 1-9.
[5] 朱晓春,张金江,毕水仙,等. 考虑高渗透光伏与电动汽车的配电网无功优化[J]. 供用电, 2024, 41(12): 110-120.
Zhu, Xiaochun, Zhang, Jinjiang, Bi, Shuixian, et al.Reactive Power Optimization for Distribution Networks Considering High Penetration of Photovoltaics and Electric Vehicles. Power Supply and Consumption, 2024, 41(12): 110-120.
[6] 方朝雄,陈浩,吴桂联,等. 考虑电池长时间尺度退化成本的配电网分布式储能与光伏逆变器协同优化[J]. 供用电, 2024, 41 (07): 12-18+38.
Fang, Zhaoxiong, Chen, Hao, Wu, Guilian, et al. Coordinated Optimization of Distributed Energy Storage and Photovoltaic Inverters in Distribution Networks Considering Long-Term Degradation Costs of Batteries. Power Supply and Consumption, 2024, 41(07): 12-18+38.
[7] 周良才,周毅,沈维健,等. 基于深度强化学习的新型电力系统无功电压优化控制[J]. 电测与仪表, 2024, 61(09): 182-189.
Zhou Liangcai, Zhou Yi, Shen Weijian, et al.Reactive Voltage Optimal Control in New-Type Power Systems Based on Deep Reinforcement Learning[J]. Electrical Measurement & Instrumentation, 2024, 61(09): 182-189.
[8] Shuai Z,Peng Y,Guerrero J M,et al.Transient response analysis of inverter-based microgrids under unbalanced conditions using a dynamic phasor model[J].IEEE Transactions on Industrial Electronics,2019,66(4):2868-2879.
[9] 李晓庆,张培超,祝炜昊,等. 基于灵敏度的光储直流配电网电压/网损自适应优化协调控制[J]. 电力建设, 2024, 45(07): 88-99.
Li Xiaoqing, Zhang Peichao, Zhu Weihao, et al.Sensitivity-Based Adaptive Optimal Coordination Control for Voltage and Network Loss in Photovoltaic and Energy Storage DC Distribution Networks[J]. Electric Power Construction, 2024, 45(07): 88-99.
[10] 曾瑶,徐玉韬,熊炜,等. 计及DSTATCOM和并网逆变器协同的高比例分布式光伏配电网鲁棒控制策略[J]. 广东电力, 2024, 37(06): 1-10.
Zeng Yao, Xu Yutao, Xiong Wei, et al.Robust Control Strategy for High-Penetration Distributed Photovoltaic Distribution Networks Considering Coordination of DSTATCOM and Grid-Connected Inverters[J]. Guangdong Electric Power, 2024, 37(6): 1-10.
[11] 全欢,胡建军,刘肇熙,等. 基于图强化学习的含光储配电网无功优化方法[J]. 广东电力, 2024, 37(12): 79-86.
Quan Hua., Hu, Jianjun, Liu Zhaoxi., et al.A Reactive Power Optimization Method for Light Storage Distribution Networks Based on Graph Reinforcement Learning. Guangdong Electric Power, 2024, 37(12): 79-86.
[12] 中华人民共和国国家标准.GB/T 33593—2017.分布式电源并网技术要求[S].北京:中国标准出版社,2017.
State Standard of the People's Republic of China.GB/T 33593—2017.Technical Requirements for Grid Connection of Distributed Resources[S].Beijing: China Standards Publishing House,2017.
[13] 中华人民共和国国家标准.GB/T37408—2019. 光伏发电并网逆变器技术要求[S].北京:中国标准出版社,2019.
State Standard of the People's Republic of China.GB/T37408—2019.Technical Requirements for Photovoltaic Gird-connected Inverter[S].Beijing: China Standards Publishing House,2019.
[14] IEEE Std1547.1—2020. IEEE Standard Conformance Test Procedures for Equipment Interconnecting Distributed Energy Resources with Electric Power Systems and Associated Interfaces[S].
[15] 何国庆,王伟胜,刘纯,等. 分布式电源并网技术标准研究[J]. 中国电力, 2020, 53 (04): 1-12+176.
He, Guoqing, Wang, Weisheng, Liu, Chun, et al. Research on Technical Standards for Distributed Generation Grid Connection. China Electric Power, 2020, 53(04): 1-12+176.
[16] 王思南. SVG在低压配电网三相不平衡治理中的应用研究[D]. 北京交通大学, 2018.
Wang Sinan.Research on the application of SVG in three-phase unbalance control of low-voltage distribution network[D]. Beijing Jiaotong University, 2018.
[17] MA K,FANG L R,KONG W W,et al.Review of distribution network phase unbalance:scale,causes,consequences, solutions , and future research directions[J] . CSEE Journal of Power and Energy Systems,2020,6(3):479-488.
[18] 王祺,秦文萍,张宇,等.不平衡工况下新能源并网变换器韧性分析及优化控制[J].电网技术,2020,44(11):4337-4346.
Wang Qi, Qin Wenping, Zhang Yu,et al.Resilience analysis and optimal control of new energy grid-connected converters under unbalanced conditions[J]. Power Grid Technology, 2020, 44(11): 4337-4346.
[19] 姜玉霞,田艳军,李永刚.有功功率载荷波动对分布式发电并网逆变器稳定影响分析及其改进控制策略[J].电网技术,2020,44(2):646-654.
Jiang Yuxia, Tian Yanjun, Li Yonggang.Analysis of the impact of active power load fluctuations on the stability of distributed generation grid-connected inverters and its improved control strategy[J]. Power Grid Technology, 2020, 44(2): 646-654.
[20] 魏石磊,田艳军,王毅,等.弱电网中增强 LCL 逆变器稳定性的虚拟阻抗控制[J].高电压技术,2019,45(6):1827-1834.
Wei Shilei, Tian Yanjun, Wang Yi, etc. Virtual impedance control to enhance the stability of LCL inverter in weak power grid[J]. High Voltage Technology, 2019, 45(6): 1827-1834.
[21] 叶满园,任威,吴韩,等.基于TPWM 的 CHB 多电平逆变器功率均衡策略研究[J].高电压技术,2020,46(8):2749-2759.
Ye Manyuan, Ren Wei, Wu Han, etc. Research on power balancing strategy of CHB multi-level inverter based on TPWM[J]. High Voltage Technology, 2020, 46(8): 2749-2759.
[22] RODRIGUEZ P,TIMBUS ATEODRESCU R,et al.Flexble active power control of distributed power generation systems during grid faults[J]. IEEE Transactions on Industrial Electronics, 2007, 54(5):2583-2592.
[23] 刘军,赵晨聪,谢宙桦等. 不平衡电网电压下基于量子粒子群并网变流器功率/电流协调控制[J]. 控制与决策, 2021, 36(04): 901-908.
Liu Jun, Zhao Chencong, Xie Zhouhua, etc. Power/current coordinated control of grid-connected converter based on quantum particle swarm under unbalanced grid voltage[J]. Control and Decision, 2021, 36(04): 901-908.
[24] LEE C, HSU C, CHENG P.A low-voltage ride-through technique for grid-connected converters of distributed energy resources[J]. IEEE Transactions on Industry Applications, 2011, 47(4): 1821-1832.
[25] CAMACHO A,CASTILLA M,MIRET J,et al.Flexible voltage support control for three-phase distributed generation inverters undergrid fault[J].IEEE Transactions on Industrial Electronics,2013,60(4):1429-1441.
[26] MIRET J,CAMACHO A,CASTILLA M,et al.Control scheme with voltage support capability for distributed generation invertersunder voltage sags[J].IEEE Transactions on Power Electronics,2013,28(11):5252-5262.
[27] 程勇,罗长青,陈刘鑫. 结合虚拟阻抗的分数阶PI-准比例谐振不平衡电压控制策略[J]. 电力建设, 2021, 42(05): 130-137.
Cheng Yong, Luo Changqing, Chen Liuxin.Fractional-Order PI-Quasi-Proportional Resonance Control Strategy for Unbalanced Voltage with Virtual Impedance[J]. Electric Power Construction, 2021, 42(05): 130-137.
[28] 彭星,姜飞,涂春鸣,等.不对称故障下光伏逆变器的最优电压支撑策略[J].电网技术,2021,45(11):4259-4268.
Peng Xing, Jiang Fei, Tu Chunming, et al.Optimal voltage support strategy for photovoltaic inverters under asymmetric fault[J]. Power Grid Technology, 2021, 45(11): 4259-4268.
[29] 漆汉宏,王晓娜,魏艳君,等.消除有功振荡的改进低电压穿越方法[J].电工技术学报,2014,29(S1):416-423.
Qi Hanhong, Wang Xiaona, Wei Yanjun, et al.Improved low voltage ride-through method to eliminate active oscillation[J]. Journal of Electrical Engineering, 2014, 29(S1): 416-423.
[30] 王卫,宫成,曹文远,等. 交直流配电网交流侧非对称故障情况下直流侧电压波动特性分析与控制[J]. 电力建设, 2021, 42(11): 90-99.
Wang Wei, Gong Cheng, Cao Wenyuan, et al.Analysis and Control of DC Side Voltage Fluctuation Characteristics Under Asymmetric Faults on the AC Side of AC-DC Distribution Networks[J]. Electric Power Construction, 2021, 42(11): 90-99.
[31] 李建文,雷亚雄,李永刚,等.并网逆变器电压支撑的参考电流值[J].电工技术学报,2015,30(10):276-282.
Li Jianwen, Lei Yaxiong, Li Yonggang, et al.Reference current value for grid-connected inverter voltage support[J]. Journal of Electrical Engineering, 2015, 30(10): 276-282.
[32] 苗常海, 杨东升, 寇健. 基于负序电压前馈的非对称故障下低电压穿越控制方法研究[J].太阳能学报 ,2018, 39(4): 1149-1155.
MIAO Changhai, YANG Dongsheng, KOU Jian.Researchof low voltage ride through control strategy based onnegative sequence voltage feedforward under unsymmetrical fault[J].Acta Energiae Solaris Sinica, 2018, 39(4):1149-1155.
[33] 陈琪蕾, 范忻蓉, 张沛超, 等. 逆变型分布式电源的灵活正负序电流控制方法与等值序网模型[J]. 电力系统保护与控制, 2018, 46(14): 57-62.
CHEN Qilei, FAN Xinrong, ZHANG Peichao, et al.Flexible positive and negative sequence current control strategy and equivalent sequence network model of inverter interfaced distributed generation[J]. Power System Protection and Control, 2018, 46(14): 57-62.
[34] 杨超颖, 王金浩, 杨赟磊, 等. 不对称故障条件下并网光伏逆变器峰值电流抑制策略[J]. 电力系统保护与控制, 2018, 46(16): 103-111.
YANG Chaoying, WANG Jinhao, YANG Yunlei, et al.Control strategy to suppress peak current for grid-connected photovoltaic inverter under unbalanced voltage sags[J].Power System Protection and Control, 2018, 46(16):103-111.
[35] 李英量,蔡鹤鸣,王康,等. 改善不平衡配电网电压质量的分布式储能序次优化配置方法[J]. 电力建设, 2022, 43(01): 87-95.
Li Yingliang, Cai Heping, Wang Kang, et al.Distributed Energy Storage Sequential Optimization Configuration Method for Improving Voltage Quality in Unbalanced Distribution Networks[J]. Electric Power Construction, 2022, 43(01): 87-95.
[36] 路怡,江道灼,梁一桥,等. 一种抑制含光伏电源配电网电压越限的方法[J]. 电力建设, 2020, 41(11): 87-93.
Lu Yi, Jiang Daozhuo, Liang Yiqiao, et al.A Method to Suppress Voltage Limits in Distribution Networks with Photovoltaic Power Sources[J]. Electric Power Construction, 2020, 41(11): 87-93.
[37] GUO Xiaoqiang, ZHANG Xue, WANG Baocheng, et al.Asymmetrical grid fault ride-through strategy of three-phase grid-connected inverter considering network impedance impact in low-voltage grid[J] . IEEE Transactions on Power Electronics ,2014,29(3):1064-1068.
[38] CAMACHO A, CASTILLA M, MIRET J, et al.Positive and negative sequence control strategies to maximize the voltage support in resistive-inductive grids during grid faults[J]. IEEE Transactions on Power Electronics, 2018, 33(6): 5362-5373.
[39] GARNICA M, DE VICUÑA L G, MIRET J, et al. Optimal voltage-support control for distributed generation inverters in RL grid-faulty networks[J]. IEEE Transactions on Industrial Electronics, 2020, 67(10): 8405-8415 .
[40] 邢超,肖家杰,李培强等. 不对称故障下考虑故障时间的储能变流器动态电压支撑策略研究[J]. 湖南大学学报(自然科学版), 2023, 50(10): 68-76.
Xing Chao, Xiao Jiajie, Li Peiqiang, et al.Research on dynamic voltage support strategy of energy storage converter considering failure time under asymmetric fault[J]. Journal of Hunan University (Natural Science Edition), 2023, 50(10): 68-76.
[41] 谢少军,季林,许津铭.并网逆变器电网阻抗检测技术综述[J].电网技术,2015,39(2):320-326.
Xie Shaojun, Ji Lin, Xu Jinming.A review of grid impedance detection technology for grid-connected inverters[J]. Power Grid Technology, 2015, 39(2): 320-326.
[42] Wang Jianhong, Xu, Wangkun, Gu, Yunjie, et al.Multi-Agent Reinforcement Learning for Active Voltage Control on Power Distribution Networks[C]//35th Conference on Neural Information Processing Systems, 2021:3271-3284.