Oscillation Frequency Detection Methods Based on Jump Point Detection and Second-Order Generalized Integrator Frequency-Locked Loop for DC Power Distribution Systems
Fan Youlin1, Wang Yue1, Wang Tonglu1, Zhao Bi'an1, Su Xinyang2
1. State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong University Xi'an 710049 China; 2. Department of Electrical and Electronic Engineering The Hong Kong Polytechnic University Hong Kong 999077 China
Abstract：TThe DC distribution power system is gradually being widely used due to its low power loss and easy control of power flow. However, its high degree of power electronicization can cause impedance mismatches between power electronic devices, leading to system oscillation. The virtual impedance strategy has become the mainstream solution due to its low cost and lack of need for external devices. However, in practical DC distribution power systems, such as data center power supply systems, changes in oscillation frequency caused by frequent alterations in system structure and external parameters limit their oscillation-suppressing effect. This paper proposes two oscillation frequency detection methods: one based on the jump point detection method and the other on the second-order generalized integrator frequency-locked loop (SOGI-FLL). To solve the oscillation problem in DC distribution power systems, the actual multi-parallel system is first simplified into a typical cable-converter cascade system. While the source and load side impedance models are established separately, impedance criteria are used to determine system stability. Then, the stability principle and key parameters of the virtual impedance strategy are introduced, and the effectiveness of suppressing oscillations with virtual impedance is theoretically verified. The oscillation frequency detection method based on the jump point detection method is proposed. The principle of the traditional peak valley detection method for detecting oscillation frequency is introduced. The problems existing in its application process are analyzed. Then, a jump point detection algorithm is introduced to expand the applicability. Meanwhile, the frequency extraction principle of the jump point detection algorithm is derived, and an adaptive oscillation suppression strategy is designed in combination with the traditional virtual impedance strategy. Based on the actual cable and transformer operating conditions, the algorithm parameters are reasonably intended. Then, this paper proposes an oscillation frequency detection method based on SOGI-FLL. The frequency extraction principle of SOGI-FLL is introduced. Combined with the traditional virtual impedance strategy, it is incorporated into the design of an adaptive oscillation suppression strategy for the DC system. The principles of parameter selection are derived, and the impact of parameters on system performance is analyzed. The results on the 48 V to 60 V/500 W platform indicate that both proposed oscillation frequency detection algorithms can extract single-frequency ripple frequencies with excellent accuracy. The suppression effect of two algorithms is tested when the cable changes. The results indicate that, combined with the virtual impedance strategy, the two proposed oscillation frequency detection strategies can suppress system oscillations. The oscillation frequency detection method based on SOGI-FLL offers higher frequency extraction accuracy and a wider frequency extraction range. In contrast, the method based on jump point detection provides faster frequency extraction speed and reduced computing power consumption. Meanwhile, both strategies have good wideband applicability.
樊囿麟, 王跃, 王彤鹭, 赵笔安, 苏鑫洋. 基于跳点检测及二阶广义积分器-锁频环流配电系统振荡频率检测方法[J]. 电工技术学报, 2026, 41(10): 3396-3410.
Fan Youlin, Wang Yue, Wang Tonglu, Zhao Bi'an, Su Xinyang. Oscillation Frequency Detection Methods Based on Jump Point Detection and Second-Order Generalized Integrator Frequency-Locked Loop for DC Power Distribution Systems. Transactions of China Electrotechnical Society, 2026, 41(10): 3396-3410.
[1] Xia Yanghong, Wei Wei, Long Teng, et al.New analysis framework for transient stability evaluation of DC microgrids[J]. IEEE Transactions on Smart Grid, 2020, 11(4): 2794-2804. [2] 王慧, 赵书强, 陈旭博, 等. 含类虚拟同步发电机和柔性负荷的直流微电网大信号稳定控制方法[J]. 电工技术学报, 2025, 40(3): 705-716. Wang Hui, Zhao Shuqiang, Chen Xubo, et al.Large signal stability control method of DC microgrid with analogous virtual synchronous generator and flexible load[J]. Transactions of China Electrotechnical Society, 2025, 40(3): 705-716. [3] Xu Luona, Guerrero J M, Lashab A, et al.A review of DC shipboard microgrids: part I: power architectures, energy storage, and power converters[J]. IEEE Transa- ctions on Power Electronics, 2022, 37(5): 5155-5172. [4] 谢文强, 韩民晓, 严稳利, 等. 考虑恒功率负荷特性的直流微电网分级稳定控制策略[J]. 电工技术学报, 2019, 34(16): 3430-3443. Xie Wenqiang, Han Minxiao, Yan Wenli, et al.Hierarchical stability control strategy of DC micro- grid considering constant power load performance[J]. Transactions of China Electrotechnical Society, 2019, 34(16): 3430-3443. [5] 张泽华, 宋桂英, 张晓璐, 等. 考虑恒功率负载的直流微电网稳定性与鲁棒性控制策略[J]. 电工技术学报, 2023, 38(16): 4391-4405. Zhang Zehua, Song Guiying, Zhang Xiaolu, et al.Stability and robustness control strategy of DC micro- grid considering constant power load[J]. Transactions of China Electrotechnical Society, 2023, 38(16): 4391-4405. [6] 逯华, 王喜莲, 周锦晗, 等. 基于虚拟阻抗的车网耦合系统低频振荡抑制[J]. 电工技术学报, 2025, 40(11): 3381-3394. Lu Hua, Wang Xilian, Zhou Jinhan, et al.Low- frequency oscillation suppression of EMUs-traction network coupling system based on virtual impe- dance[J]. Transactions of China Electrotechnical Society, 2025, 40(11): 3381-3394. [7] Middlebrook R D, Cuk S.A general unified approach to modelling switching-converter power stages[C]// 1976 IEEE Power Electronics Specialists Conference, Cleveland, OH, USA, 1976: 18-34. [8] Wildrick C M, Lee F C, Cho B H, et al.A method of defining the load impedance specification for a stable distributed power system[J]. IEEE Transactions on Power Electronics, 1995, 10(3): 280-285. [9] Feng Xiaogang, Liu Jinjun, Lee F C.Impedance specifications for stable DC distributed power systems[J]. IEEE Transactions on Power Electronics, 2002, 17(2): 157-162. [10] Sun Jian.Impedance-based stability criterion for grid- connected inverters[J]. IEEE Transactions on Power Electronics, 2011, 26(11): 3075-3078. [11] 刘笑, 杨建, 李力, 等. 基于机器学习的带被动阻尼直流微电网系统的稳定性检测[J]. 电工技术学报, 2024, 39(8): 2281-2293, 2324. Liu Xiao, Yang Jian, Li Li, et al.Stability detection of DC microgrid systems with passive damping based on machine learning[J]. Transactions of China Electro- technical Society, 2024, 39(8): 2281-2293, 2324. [12] Cao Xin, Zhong Qingchang, Ming Wenlong.Ripple eliminator to smooth DC-bus voltage and reduce the total capacitance required[J]. IEEE Transactions on Industrial Electronics, 2015, 62(4): 2224-2235. [13] Wang Ruxi, Wang Fei, Boroyevich D, et al.A high power density single-phase PWM rectifier with active ripple energy storage[J]. IEEE Transactions on Power Electronics, 2011, 26(5): 1430-1443. [14] 杜韦静, 张军明, 钱照明. Buck变流器级联系统直流母线电压补偿控制策略[J]. 电工技术学报, 2015, 30(1): 135-142. Du Weijing, Zhang Junming, Qian Zhaoming.Com- pensation methodology for DC bus voltage of cascaded system formed by Buck converters[J]. Transactions of China Electrotechnical Society, 2015, 30(1): 135-142. [15] 王成山, 李微, 王议锋, 等. 直流微电网母线电压波动分类及抑制方法综述[J]. 中国电机工程学报, 2017, 37(1): 84-98. Wang Chengshan, Li Wei, Wang Yifeng, et al.DC bus voltage fluctuation classification and restraint methods review for DC microgrid[J]. Proceedings of the CSEE, 2017, 37(1): 84-98. [16] He Bangbang, Chen Wu, Li Xin, et al.A power adaptive impedance reshaping strategy for cascaded DC system with Buck-type constant power load[J]. IEEE Transactions on Power Electronics, 2022, 37(8): 8909-8920. [17] 张勤进, 张博, 刘彦呈, 等. 基于低频电流注入的船舶直流微电网线路阻抗检测[J]. 电力系统保护与控制, 2020, 48(8): 134-140. Zhang Qinjin, Zhang Bo, Liu Yancheng, et al.A line impedance detection of a ship DC microgrid based on low frequency current injection[J]. Power System Protection and Control, 2020, 48(8): 134-140. [18] Liu Zipeng, Liu Jinjun, Liu Zeng.A sampling opti- mized method for frequency response measurement in power electronics systems[J]. IEEE Transactions on Power Electronics, 2022, 37(7): 8447-8464. [19] Su Xinyang, Wang Minghao, Zhao Bian, et al.An adaptive compensated virtual impedance method for oscillation suppression in DC distribution power systems[J]. IEEE Transactions on Industrial Elec- tronics, 2025, 72(5): 4854-4864. [20] Man Jiufang, Chen Lei, Terzija V, et al.Mitigating high-frequency resonance in MMC-HVDC systems using adaptive Notch filters[J]. IEEE Transactions on Power Systems, 2022, 37(3): 2086-2096. [21] Sun Jian, Buchhagen C.Self-adaptive detection and damping of power system resonances involving con- verters[C]//2022 IEEE 23rd Workshop on Control and Modeling for Power Electronics (COMPEL), Tel Aviv, Israel, 2022: 1-8. [22] 邵振华, 陈冲, 林瑞全. 基于复合二阶广义积分的频率自适应谐波电流检测[J]. 电力自动化设备, 2012, 32(6): 51-55, 65. Shao Zhenhua, Chen Chong, Lin Ruiquan.Harmonic current detection with adaptive frequency tracking based on multiple second-order generalized integr- ators[J]. Electric Power Automation Equipment, 2012, 32(6): 51-55, 65. [23] Zhang Xin, Zhong Qingchang, Ming Wenlong.Stabi- lization of a cascaded DC converter system via adding a virtual adaptive parallel impedance to the input of the load converter[J]. IEEE Transactions on Power Electronics, 2016, 31(3): 1826-1832. [24] Qu Zhi, Ebrahimi S, Amiri N, et al.Adaptive control method for stabilizing DC distribution systems with constant-power loads based on tunable active damping[C]//2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL), Padua, Italy, 2018: 1-6. [25] 郑凯元, 杜文娟, 王海风. 聚合恒功率负荷对直流微电网稳定性影响的阻抗法分析[J]. 电网技术, 2021, 45(1): 134-148. Zheng Kaiyuan, Du Wenjuan, Wang Haifeng.DC microgrid stability affected by aggregated constant power loads based on impedance method[J]. Power System Technology, 2021, 45(1): 134-148. [26] Ahmadi R, Paschedag D, Ferdowsi M.Closed-loop input and output impedances of DC-DC switching converters operating in voltage and current mode control[C]//IECON 2010-36th Annual Conference on IEEE Industrial Electronics Society, Glendale, AZ, USA, 2010: 2311-2316. [27] Rodríguez P, Luna A, Muñoz-Aguilar R S, et al. A stationary reference frame grid synchronization system for three-phase grid-connected power converters under adverse grid conditions[J]. IEEE Transactions on Power Electronics, 2012, 27(1): 99-112. [28] Rodriguez P, Luna A, Candela I, et al.Grid syn- chronization of power converters using multiple second order generalized integrators[C]//2008 34th Annual Conference of IEEE Industrial Electronics, Orlando, FL, USA, 2008: 755-760.
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