Flexible Power Assignment Method for Railway Power Flow Controller Considering Regenerative Braking Energy
Lin Jinjie1, Li Yong1, Hu Sijia1, Zhang Jie2, Luo Longfu1
1. College of Electrical and Information Engineering Hunan University Changsha 410082 China; 2. China Railway Signal & Communication (Changsha) Railway Traffic Control Technology Co. Ltd Changsha 410006 China
Abstract：With the rapid development of the Chinese electrified railway, the grid-connection-related issues in the railway power system (RPS) have become more and more prominent. To deal with those issues, various schemes, e.g., LC branches, static var compensator (SVC), and static synchronous compensator (STATCOM), are employed in the early days; however, they are not satisfactory enough from the perspective of either compensation performance or economic. The railway power flow controller (RPFC) has proven to be an effective route to deal with almost all grid-connection-related issues, while the needed large design capacity hinders its further commercialization. Many works were presented to cut down the design capacity of RPFC; however, most of them only focus on the traction mode of locomotives, which makes them lack generality and cannot be applied to the situation where regenerative braking energy (RBE) exists. To fill this gap, this paper proposes a flexible power assignment method for RPFC, in which the regenerative braking energy (RBE) is considered. The proposed method aims at reducing the converters' design capacity under the premise that the concerned system can meet the grid-connection indexes, and it can be used both in the planning and real-time control stages. Firstly, the mathematical model of an RPFC-integrated RPS adopting the V/v transformer is derived, and the relationship between RPFC's compensated power and the primary power factors (PFs) is revealed. Then, considering RBE, 16 compensation modes are developed based on the alternative positive or negative values exist in the primary PF angles, and the interaction mechanisms of primary PFs and Modes on RPFC's compensated power are investigated. Based on the two-phase loads' PF-P distribution, a precise load imitation is implemented to guide RPFC's design and performance evaluation. Finally, under the premise of meeting the concerned grid-connection indexes, a flexible power assignment method is designed, in which RBE is embraced. The real measured data-based simulation shows that, the distribution of compensation modes drawn from two-phase synchronous measured data is highly similar to the one drawn from the proposed load imitation process, and these available candidates can be pre-embedded into the controller for real-time control. By adopting the proposed method, the rating of RPFC can be reduced by almost 50% compared to the conventional full compensation method (FCM) for the studied TSS. Besides, when the PF* is chosen in the interval of [0.9, 0.93], the rating decreasing ratio is maintained at over 50%. When PF* is chosen as 0.9, the negative sequence power in the concerned system can meet the standards, and for extreme situations, PF* can be selected higher in the interval of [0.9, 0.93], while more than 50% rating decreasing ratio can still be guaranteed. Besides, the proposed method can also lower the RPFC's operating losses. Based on the testing experience of a real RPFC (10 MV·A), the daily operating losses can be evaluated, and the result indicates that by using the proposed method, the operating losses are cut down by almost 80%, which is quite considerable for long-term operation. The main contributions and conclusions are summarized as follows: (1) the designed flexible power assignment method is general and can be employed in the situation where RBE exists. Compared with the conventional FCM, the rating of RPFC can be reduced by almost 50%, and the negative sequence power of the concerned system can meet the grid-connection indexes; besides, the operating losses can be reduced by almost 80%. (2) With the consideration of RBE, the interaction mechanisms of primary PFs and the developed modes on RPFC's compensated power are revealed. (3) Considering the intrinsic correlation between loads' power and PF, the dynamic scanning method is designed to determine loads' PF interval for every specific load power, by which the precise load imitation can be implemented for the guide of RPFC's design.
林锦杰, 李勇, 胡斯佳, 张杰, 罗隆福. 计及再生制动能量的铁路潮流控制器功率柔性分配方法[J]. 电工技术学报, 2023, 38(22): 6121-6132.
Lin Jinjie1, Li Yong1, Hu Sijia1, Zhang Jie2, Luo Longfu1. Flexible Power Assignment Method for Railway Power Flow Controller Considering Regenerative Braking Energy. Transactions of China Electrotechnical Society, 2023, 38(22): 6121-6132.
[1] 李群湛, 王辉, 黄文勋, 等. 电气化铁路牵引变电所群贯通供电系统及其关键技术[J]. 电工技术学报, 2021, 36(5): 1064-1074. Li Qunzhan, Wang Hui, Huang Wenxun, et al.Interconnected power supply system of traction substation group and its key technologies for the electrified railway[J]. Transactions of China Electrotechnical Society, 2021, 36(5): 1064-1074. [2] 耿安琪, 胡海涛, 张育维, 等. 基于阶梯能量管理的电气化铁路混合储能系统控制策略[J]. 电工技术学报, 2021, 36(23): 4916-4925. Geng Anqi, Hu Haitao, Zhang Yuwei, et al.Control strategy of hybrid energy storage system for electrified railway based on increment energy management[J]. Transactions of China Electrotechnical Society, 2021, 36(23): 4916-4925. [3] 袁佳歆, 曲锴, 郑先锋, 等. 高速铁路混合储能系统容量优化研究[J]. 电工技术学报, 2021, 36(19): 4161-4169, 4182. Yuan Jiaxin, Qu Kai, Zheng Xianfeng, et al.Optimizing research on hybrid energy storage system of high speed railway[J]. Transactions of China Electrotechnical Society, 2021, 36(19): 4161-4169, 4182. [4] 周建佳, 胡成, 杨苏飞. 基于UPQC的电气化铁路同相供电方案的研究[J]. 电气技术, 2010, 11(1): 14-17. Zhou Jianjia, Hu Cheng, Yang Sufei.Research on A scheme of cophase power supply system for electrified railways based on UPQC[J]. Electrical Engineering, 2010, 11(1): 14-17. [5] Zhang Dinghua, Zhang Zhixue, Wang Weian, et al.Negative sequence current optimizing control based on railway static power conditioner in V/v traction power supply system[J]. IEEE Transactions on Power Electronics, 2016, 31(1): 200-212. [6] 刘华伟, 耿安琪, 何正友, 等. 重载铁路再生制动能量利用方案研究[J]. 电气工程学报, 2021, 16(1): 157-165. Liu Huawei, Geng Anqi, He Zhengyou, et al.Research on energy utilization scheme of regenerative braking for heavy haul railway[J]. Journal of Electrical Engineering, 2021, 16(1): 157-165. [7] 胡海涛, 陈俊宇, 葛银波, 等. 高速铁路再生制动能量储存与利用技术研究[J]. 中国电机工程学报, 2020, 40(1): 246-256, 391. Hu Haitao, Chen Junyu, Ge Yinbo, et al.Research on regenerative braking energy storage and utilization technology for high-speed railways[J]. Proceedings of the CSEE, 2020, 40(1): 246-256, 391. [8] Zhang Zhiwen, Wu Bin, Kang Jinsong, et al.A multi-purpose balanced transformer for railway traction applications[J]. IEEE Transactions on Power Delivery, 2009, 24(2): 711-718. [9] 王鹏程, 李勇, 安柏楠, 等. 基于不对称接线平衡变压器的电气化铁路电能质量混合调节系统[J]. 电工技术学报, 2019, 34(21): 4590-4600. Wang Pengcheng, Li Yong, An Bonan, et al.Asymmetrical connection balance transformer based hybrid power quality control system for electrical railway[J]. Transactions of China Electrotechnical Society, 2019, 34(21): 4590-4600. [10] Das J C.Passive filters-potentialities and limitations[C]// Conference Record of the 2003 Annual Pulp and Paper Industry Technical Conference, Charleston, SC, USA, 2003: 187-197. [11] Zhu Guiping, Chen Jianye, Liu Xiaoyu.Compensation for the negative-sequence currents of electric railway based on SVC[C]//2008 3rd IEEE Conference on Industrial Electronics and Applications, Singapore, 2008: 1958-1963. [12] Horita Y, Morishima N, Kai M, et al.Single-phase STATCOM for feeding system of Tokaido Shinkansen[C]//The 2010 International Power Electronics Conference - ECCE ASIA -, Sapporo, Japan, 2010: 2165-2170. [13] 兎束哲夫, 池戸昭治, 上田啓二, 等. 新幹線用電圧変動補償装置の開発と実用化[J]. 電気学会論文誌B(電力・エネルギー部門誌), 2005, 125(9): 885-892. [14] Hiroshi O, Tomomi K, Akio S.Railway static power conditioner for Shin-Kurobe substation of Hokuriku Shinkansen[J]. Fuji Electric Review, 2015, 88(1): 56-61. [15] 谢斌. 高速电气化铁路大容量电能质量调节系统理论与应用研究[D]. 长沙: 湖南大学, 2018. [16] 魏文婧, 胡海涛, 王科, 等. 基于铁路功率调节器的高速铁路牵引供电系统储能方案及控制策略[J]. 电工技术学报, 2019, 34(6): 1290-1299. Wei Wenjing, Hu Haitao, Wang Ke, et al.Energy storage scheme and control strategies of high-speed railway based on railway power conditioner[J]. Transactions of China Electrotechnical Society, 2019, 34(6): 1290-1299. [17] Cui Guiping, Luo Longfu, Liang Chonggan, et al.Supercapacitor integrated railway static power conditioner for regenerative braking energy recycling and power quality improvement of high-speed railway system[J]. IEEE Transactions on Transportation Electrification, 2019, 5(3): 702-714. [18] 马茜, 郭昕, 罗培, 等. 基于超级电容储能的新型铁路功率调节器协调控制策略设计[J]. 电工技术学报, 2019, 34(4): 765-776. Ma Qian, Guo Xin, Luo Pei, et al.Coordinated control strategy design of new type railway power regulator based on super capacitor energy storage[J]. Transactions of China Electrotechnical Society, 2019, 34(4): 765-776. [19] Luo Pei, Li Qianru, Zhou Yang, et al.Multi-application strategy based on railway static power conditioner with energy storage system[J]. IEEE Transactions on Intelligent Transportation Systems, 2021, 22(4): 2140-2152. [20] Ma Fujun, Wang Xin, Deng Lingfeng, et al.Multiport railway power conditioner and its management control strategy with renewable energy access[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 8(2): 1405-1418. [21] 胡斯佳, 张志文, 李勇, 等. 一种采用LC耦合的电气化铁道功率调节系统[J]. 电工技术学报, 2016, 31(8): 199-211. Hu Sijia, Zhang Zhiwen, Li Yong, et al.An LC-coupled electric railway static power conditioning system[J]. Transactions of China Electrotechnical Society, 2016, 31(8): 199-211. [22] 张志文, 王丹, 胡斯佳, 等. 一种混合型电气化铁道电能质量综合治理系统及其容量分析[J]. 电力自动化设备, 2014, 34(12): 89-94. Zhang Zhiwen, Wang Dan, Hu Sijia, et al.Hybrid railway power quality improvement system and its power capacity analysis[J]. Electric Power Automation Equipment, 2014, 34(12): 89-94. [23] Chen Baichao, Zhang Chenmeng, Zeng Wenjun, et al.Electrical magnetic hybrid power quality compensation system for V/V traction power supply system[J]. IET Power Electronics, 2016, 9(1): 62-70. [24] 张鑫, 江全元. 基于V/V接线变压器的铁路功率调节器容量配置和能量优化补偿策略[J]. 电力自动化设备, 2014, 34(1): 102-108. Zhang Xin, Jiang Quanyuan.Capacity configuration of V/V transformer-based railway power conditioner and optimal energy compensation strategy[J]. Electric Power Automation Equipment, 2014, 34(1): 102-108. [25] 肖非然, 倪周, 闵永智, 等. 一种基于多智能体的多站协同高速铁路不平衡补偿方法[J]. 电工技术学报, 2020, 35(16): 3518-3528. Xiao Feiran, Ni Zhou, Min Yongzhi, et al.Unbalanced compensation method of multi-station cooperative for high-speed railway based on multi-agent[J]. Transactions of China Electrotechnical Society, 2020, 35(16): 3518-3528. [26] Hu Sijia, Li Sheng, Li Yong, et al.A balance transformer-integrated RPFC for railway power system PQ improvement with low-design capacity[J]. IEEE Transactions on Industrial Electronics, 2018, 65(4): 2925-2934. [27] Hu Sijia, Li Sheng, Li Yong, et al.A comprehensive study for the power flow controller used in railway power systems[J]. IEEE Transactions on Industrial Electronics, 2018, 65(8): 6032-6043. [28] 中国国家标准化管理委员会. 电能质量三相电压不平衡度: GB/T15543—2008[S]. 北京: 中国质检出版社, 2008.
2023, Vol. 38 
