Integrated Voltage Loop Device and Control Strategy Based on Improved Phase-Shifting Transformers
Yang Yongchun1, Du Xiangyu1, Tang Jianxiong2, Chen Xuntong1, Zhao Chengyong1
1. State Key Laboratory of New Energy North China Electric Power University Baoding 071003 China; 2. State Grid Chongqing Electric Power Company Shinan Power Supply Branch Chongqing 401336 China
Abstract:Due to the existence of important loads, the new distribution network needs to be supplied with power when the equipment of the original distribution network is overhauled. Two closing types exist when accessing the new distribution network: loop and ring-closing. The distribution network is cut off for loop closing, leading to power supply interruption, or the ring of the distribution network is directly closed, producing a large impulse current due to the large voltage difference between the two distribution networks. As a result, the relay protection malfunction occurs, which affects the reliability and stability of the power grid. Two ways are adopted to avoid the above issues. One is to provide the loop closing condition through theoretical calculation, and the voltage of the loop closing point is similar by controlling the whole distribution network. The loop is directly closed after meeting the ring closing conditions. However, the control process is more complex, and the loop closing current is still large. The second is to use the voltage regulating device to change the voltage of one side of the ring closing point and carry out the ring-closing. Although the control effect of the ring-closing device is better, the price and maintenance costs are high. This paper proposes an improved phase shifter (IPST) with an amplitude modulation winding (ETm) based on the amplitude modulation winding (ETp) of the traditional phase shifter. It can flexibly change the voltage amplitude and phase by adjusting the gears of ETp and ETm, thereby changing the voltage at the closing point. The voltage between the two distribution networks is similar, and the loop closure is realized. In addition, the voltage quality on the load side is degraded because of the internal impedance of the IPST after the load transfer. An IPST equivalence model is established based on the multi-port network theory. The impedance characteristics of the IPST port are converted into the equivalent analytical formula. The functional expressions of the regulation voltage on the amplitude modulation gear Tm and phase modulation gear Tp are derived. Thus, the target gear of the IPST is predicted, and the voltage quality is improved. Thirdly, to address the problem of the inrush current generated when the IPST exits bypass closing, the functional relationship of the inrush current on the IPST gear is derived. The IPST target gear is predicted by combining the current regulation target and the voltage quality constraint. The voltage quality can be ensured, and the impulse current can drop and safely exit the IPST. Finally, the impedance expression’s correctness and the control strategy’s effectiveness are verified through PSCAD/ EMTDC.
杨用春, 杜翔宇, 唐健雄, 陈巽同, 赵成勇. 基于改进移相变压器的综合调压合环装置及调控策略[J]. 电工技术学报, 2025, 40(8): 2532-2546.
Yang Yongchun, Du Xiangyu, Tang Jianxiong, Chen Xuntong, Zhao Chengyong. Integrated Voltage Loop Device and Control Strategy Based on Improved Phase-Shifting Transformers. Transactions of China Electrotechnical Society, 2025, 40(8): 2532-2546.
[1] 颜湘武, 邵晨, 吴鸣, 等. 基于电磁式旋转潮流控制器的有源配电网多场景控制[J]. 电工技术学报, 2023, 38(增刊1): 44-55. Yan Xiangwu, Shao Chen, Wu Ming, et al.Multi-scene control method of active distribution network based on electromagnetic rotating power flow con-troller[J]. Transactions of China Electrotechnical Society, 2023, 38(S1): 44-55. [2] 吴振辉, 彭晓涛, 沈阳武, 等. 一种配电网环型供电模型及其合环运行方式的研究[J]. 中国电机工程学报, 2013, 33(10): 57-63. Wu Zhenhui, Peng Xiaotao, Shen Yangwu, et al.Study on a loop power supply model and its loop-close operation mode for distribution network[J]. Proceedings of the CSEE, 2013, 33(10): 57-63. [3] 夏翔, 熊军, 胡列翔. 地区电网的合环潮流分析与控制[J]. 电网技术, 2004, 28(22): 76-80. Xia Xiang, Xiong Jun, Hu Liexiang.Analysis and control of loop power flow in regional power network[J]. Power System Technology, 2004, 28(22): 76-80. [4] 王怡, 杨知方, 余娟, 等. 考虑可靠性需求的配电网多种设备统一优化配置[J]. 电工技术学报, 2023, 38(24): 6727-6743. Wang Yi, Yang Zhifang, Yu Juan, et al.A unified optimal placement method for multiple types of devices in distribution networks considering reliabi-lity demand[J]. Transactions of China Electrotech-nical Society, 2023, 38(24): 6727-6743. [5] 章坚民, 相炜, 罗刚, 等. 配电网30°相角差线路不停电转供的解决方案及关键分析[J]. 电力系统自动化, 2018, 42(1): 74-81. Zhang Jianmin, Xiang Wei, Luo Gang, et al.Solution and its key issue analysis for load transfer without power interruption of distribution lines with 30° phase angle difference[J]. Automation of Electric Power Systems, 2018, 42(1): 74-81. [6] 张亮, 章坚民, 金乃正, 等. 配电网30°相角差线路不停电转供的混合顺控方法及试点验证[J]. 电力系统自动化, 2018, 42(2): 128-135, 153. Zhang Liang, Zhang Jianmin, Jin Naizheng, et al.Hybrid sequence control and pilot project verification for none-electricity-cut load transferring of distri-bution lines with 30 degree phase angle difference[J]. Automation of Electric Power Systems, 2018, 42(2): 128-135, 153. [7] 陈厚合, 丛前, 姜涛, 等. 多能协同的配电网供电恢复策略[J]. 电工技术学报, 2022, 37(3): 610-622, 685. Chen Houhe, Cong Qian, Jiang Tao, et al.Distribution systems restoration with multi-energy synergy[J]. Transactions of China Electrotechnical Society, 2022, 37(3): 610-622, 685. [8] 杨用春, 唐健雄, 牛超群, 等. 基于移相变压器的灵活合环控制装置及控制策略研究[J]. 华北电力大学学报(自然科学版), 2022, 49(1): 48-57. Yang Yongchun, Tang Jianxiong, Niu Chaoqun, et al.Research on flexible loop-closing control device and control strategy based on phase shifting transfor-mer[J]. Journal of North China Electric Power Univer-sity (Natural Science Edition), 2022, 49(1): 48-57. [9] 赖胜杰, 夏成军, 纪焕聪, 等. 计及负荷等值阻抗的配电网合环转供电分析模型[J]. 电工技术学报, 2022, 37(11): 2859-2868. Lai Shengjie, Xia Chengjun, Ji Huancong, et al.An analysis model for power transfer from loop closing in distribution network considering load equivalent impedance[J]. Transactions of China Electrotechnical Society, 2022, 37(11): 2859-2868. [10] 石钟文, 温辉, 杨利森, 等. 基于改进算法的10 kV配电网合环稳态电流计算[J]. 智慧电力, 2023, 51(3): 111-118. Shi Zhongwen, Wen Hui, Yang Lisen, et al.Calculation of loop closing steady-state current in 10 kV distribution network based on improved algorithm[J]. Smart Power, 2023, 51(3): 111-118. [11] 刘健, 孙泉, 张小庆, 等. 配电网合环分析与合环条件判断[J]. 电力系统自动化, 2014, 38(11): 130-135. Liu Jian, Sun Quan, Zhang Xiaoqing, et al.Analysis on and criteria for loop closing operation for distribution grids[J]. Automation of Electric Power Systems, 2014, 38(11): 130-135. [12] 欧阳金鑫, 陈纪宇, 袁毅峰, 等. 基于分布式电源主动控制的配电网合环电压波动抑制方法[J]. 电力自动化设备, 2024, 44(1): 49-56. Ouyang Jinxin, Chen Jiyu, Yuan Yifeng, et al.Suppression method of loop closing voltage fluctuation in distribution network based on active control of distributed generator[J]. Electric Power Automation Equipment, 2024, 44(1): 49-56. [13] 王旭东. 基于分布式发电和柔性负荷的配电网合环电压综合调节方法研究[J]. 电气应用, 2019, 38(10): 76-83. Wang Xudong.Comprehensive regulation method study of distribution network closed-loop voltage based on distributed generations and flexible loads[J]. Electrotechnical Application, 2019, 38(10): 76-83. [14] 杨用春, 牛超群, 唐健雄, 等. 基于双VSC的柔性合环装置的交直流侧合环控制策略研究[J]. 华北电力大学学报(自然科学版), 2023, 50(2): 1-9. Yang Yongchun, Niu Chaoqun, Tang Jianxiong, et al.Research on the control strategy of AC and DC side loop-closing of flexible loop-closing device based on double VSC[J]. Journal of North China Electric Power University (Natural Science Edition), 2023, 50(2): 1-9. [15] 邵云峰, 刘永强, 马中静, 等. 基于蓄电池储能系统的电网合环技术研究[J]. 电器与能效管理技术, 2020(10): 27-35, 54. Shao Yunfeng, Liu Yongqiang, Ma Zhongjing, et al.Research on grid loop closing techniques based on battery energy storage systems[J]. Electrical & Energy Management Technology, 2020(10): 27-35, 54. [16] 仉志华. 基于UPFC的自愈配电环网及其潮流优化控制技术的研究[D]. 济南: 山东大学, 2012. Zhang Zhihua.Research on self-healing distribution ring network based on UPFC and its power flow optimization control technology[D]. Jinan: Shandong University, 2012. [17] Yuan Jiaxin, Zhang Weizhe, Mei Jiajun, et al.Independent fast phase shifting transformer: a flexible and high-precision power flow controller[J]. IEEE Transactions on Power Delivery, 2023, 38(6): 4410-4421. [18] 余梦泽, 李峰, 李作红, 等. 移相变压器原理、拓扑、应用及发展[J]. 武汉大学学报(工学版), 2023, 56(10): 1224-1237. Yu Mengze, Li Feng, Li Zuohong, et al.Principle, topology, application and development of phase-shifting transformer[J]. Geomatics and Engineering Science of Wuhan University, 2023, 56(10): 1224-1237. [19] 杨用春, 唐健雄, 牛超群, 等. 基于IPST的合环装置三相不对称下耦合特性及控制策略[J]. 电力系统自动化, 2022, 46(14): 158-168. Yang Yongchun, Tang Jianxiong, Niu Chaoqun, et al.Coupling characteristic and control strategy for loop closing device based on improved phase shifting transformer under three-phase asymmetry con-dition[J]. Automation of Electric Power Systems, 2022, 46(14): 158-168. [20] 赵镜红, 周长朵, 王涵铭, 等. 计及边端效应的直线式移相变压器等效电路分析[J]. 电工技术学报, 2024, 39(6): 1792-1805. Zhao Jinghong, Zhou Changduo, Wang Hanming, et al.Equivalent circuit analysis of linear phase-shifting transformer considering edge effect[J]. Transactions of China Electrotechnical Society, 2024, 39(6): 1792-1805. [21] 高飞, 刘欣, 王利桐, 等. 对称双芯移相变压器有载分接开关最大级电压计算方法研究[J]. 中国电机工程学报, 2017, 37(7): 2110-2119. Gao Fei, Liu Xin, Wang Litong, et al.Study on the maximum step voltage calculation method of on-load tap changer in symmetrical two-core phase shifting transformer[J]. Proceedings of the CSEE, 2017, 37(7): 2110-2119. [22] Liang Guishu, Wang Litong, Gao Fei, et al.A new maximum step voltage calculation method of on-load tap-changer for symmetrical two-core phase-shifting transformer[J]. IEEE Transactions on Power Delivery, 2018, 33(6): 2718-2725. [23] 卜亮, 韩松, 周超, 等. 基于UMEC的双芯Sen变压器电磁暂态模型[J]. 电网技术, 2021, 45(8): 3283-3290. Bu Liang, Han Song, Zhou Chao, et al.Electro-magnetic transient model of two-core Sen transformer based on UMEC[J]. Power System Technology, 2021, 45(8): 3283-3290. [24] 杨庆, 崔浩楠, 揭青松, 等. 基于对偶性原理的配电变压器高频电磁暂态模型[J]. 高电压技术, 2022, 48(4): 1498-1509. Yang Qing, Cui Haonan, Jie Qingsong, et al.High frequency electromagnetic transient model of dis-tribution transformer based on duality principle[J]. High Voltage Engineering, 2022, 48(4): 1498-1509. [25] 徐志, 刘静佳, 蒋羽鹏, 等. 基于移相变压器+调压变压器的10kV配电网合环控制装置及控制方法[J]. 南方电网技术, 2023, 17(3): 85-96. Xu Zhi, Liu Jingjia, Jiang Yupeng, et al.Loop closing control device and control method of 10kV dis-tribution network based on phase shifting transformer and voltage regulating transformer[J]. Southern Power System Technology, 2023, 17(3): 85-96. [26] 周自强, 张焰, 郭强, 等. 基于概率潮流的10 kV配电网合环操作安全性评估[J]. 电网技术, 2019, 43(4): 1421-1429. Zhou Ziqiang, Zhang Yan, Guo Qiang, et al.Security assessment of loop closing operation in 10 kV dis-tribution network based on probabilistic load flow[J]. Power System Technology, 2019, 43(4): 1421-1429. [27] 刘善伟, 郭建龙, 刘文泽, 等. 10 kV配电网电能质量综合等级评估方法研究[J]. 机电工程技术, 2021, 50(8): 152-156. Liu Shanwei, Guo Jianlong, Liu Wenze, et al.Study on the method of comprehensive grade evaluation of power quality in 10 kV distribution network[J]. Mechanical & Electrical Engineering Technology, 2021, 50(8): 152-156. [28] 刘康康. 配电网电能质量综合评估方法研究[D]. 贵阳: 贵州大学, 2022. Liu Kangkang.Research on comprehensive evaluation method of power quality in distribution network[D]. Guiyang: Guizhou University, 2022.