针对两级式储能变流器（PCS）设计过程中普遍偏重单级变换器稳定性能,忽略级联耦合效应导致系统稳定性降低、直流母线电压振荡的问题,通过建立两级式PCS直流侧端口的阻抗模型,研究功率的大小和方向对端口阻抗特性的影响,并提出一种基于电容电流观测的阻抗优化控制策略。通过重塑前、后级变换器直流侧端口的阻抗模型,降低源变换器输出阻抗的谐振峰值,削弱负载变换器输入阻抗的负阻抗特性,从而避免输入、输出阻抗幅值的相交,提高了模块级联后两级式储能变流器的稳定运行范围。此外,采用状态观测器代替电流传感器测量电容电流,降低了成本。最后,通过仿真和实验验证了所提控制策略的有效性。
Abstract
To address the problem that the design of two-stage power conversion system （PCS） for energy storage generally emphasizes the stability of individual converters while ignoring the cascading coupling effect, which degrades system stability and triggers DC bus voltage oscillation, this paper establishes an impedance model of the DC-side ports in the two-stage PCS, investigates the influence of power magnitude and direction on port impedance characteristics, and an impedance optimization control strategy based on capacitor current observation is proposed. By reshaping the impedance models of the DC-side ports in both front-stage and rear-stage converters, this strategy reduces the resonance peak of the source converter’s output impedance and mitigates the negative impedance characteristics of the load converter’s input impedance, thereby avoiding intersections between input and output impedance magnitudes and enhancing the stable operational range of the cascaded two-stage PCS. Additionally, a state observer replaces current sensors for capacitor current measurement, reducing costs. Finally, simulations and experiments validate the effectiveness of the proposed control strategy.
关键词
储能 /
级联控制系统 /
稳定性分析 /
阻抗重塑 /
状态观测器
Key words
energy storage /
cascade control systems /
stability analysis /
impedance reshaping /
state observer
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 王永真, 康利改, 张靖, 等. 综合能源系统的发展历程、典型形态及未来趋势[J]. 太阳能学报, 2021(8): 84-95.
Wang Y Z, Kang L G, Zhang J, et al.Development history, typical form and future trend of integrated energy system[J]. Acta Energiae Solaris Sinica, 2021(8): 84-95.
[2] 吴智泉, 贾纯超, 陈磊, 等. 新型电力系统中储能创新方向研究[J]. 太阳能学报, 2021, 42(10): 444-451.
Wu Z Q, Jia C C, Chen L, et al.Research on innovative direction of energy storage in new power system construction[J]. Acta Energiae Solaris Sinica, 2021, 42(10): 444-451.
[3] 张耀文, 张政权, 刘庆想, 等. 新型双向储能变流器分析与研究[J]. 太阳能学报, 2022, 43(4): 82-89.
Zhang Y W, Zhang Z Q, Liu Q X, et al.Analysis and research of new bidirectional energy storage converter[J]. Acta Energiae Solaris Sinica, 2022, 43(4): 82-89.
[4] 任永峰, 胡宏彬, 薛宇, 等. 全钒液流电池-超级电容混合储能平抑直驱式风电功率波动研究[J]. 高电压技术, 2015, 41(7): 2127-2134.
Ren Y F, Hu H B, Xue Y, et al.Vanadium redox battery-super capacitor hybrid energy storage system for smooth direct-drive wind turbine power fluctuation[J]. High Voltage Engineering, 2015, 41(7): 2127-2134.
[5] 高娟, 秦岭, 茅靖峰, 等. 分体式储能VSG功率转换系统输出电压鲁棒控制器设计[J]. 电网技术, 2022, 46(1): 213-219.
Gao J, Qin L, Mao J F, et al.Output voltage robust controller design for the power converter system in the assembled VSG[J]. Power System Technology, 2022, 46(1): 213-219.
[6] 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 C S, Li W, Wang Y F, et al.DC bus voltage fluctuation classification and restraint methods review for DC microgrid[J]. Proceedings of the CSEE, 2017, 37(1): 84-98.
[7] Khalid M, Panigrahi B K.Physical model-based VDCM control to enhance the inertia of DC bus for PV-BESS supported off-board charging station[J]. IEEE Transactions on Transportation Electrification, 2024, 10(2): 4334-4346.
[8] Riccobono A, Santi E.Comprehensive review of stability criteria for DC power distribution systems[J]. IEEE Transactions on Industry Applications, 2014, 50(5): 3525-3535.
[9] Zhang X, Ruan X B, Tse C K.Impedance-based local stability criterion for DC distributed power systems[J]. IEEE Transactions on Circuits and Systems I: Regular Papers, 2015, 62(3): 916-925.
[10] Wen B, Boroyevich D, Burgos R, et al.Inverse nyquist stability criterion for grid-tied inverters[J]. IEEE Transactions on Power Electronics, 2017, 32(2): 1548-1556.
[11] Cespedes M, Xing L, Sun J.Constant-power load system stabilization by passive damping[J]. IEEE Transactions on Power Electronics, 2011, 26(7): 1832-1836.
[12] Li X, Ruan X B, Xiong X L, et al.Stability issue of cascaded systems with consideration of switching ripple interaction[J]. IEEE Transactions on Power Electronics, 2019, 34(7): 7040-7052.
[13] Lorzadeh O, Lorzadeh I, Soltani M N, et al.Source-side virtual RC damper-based stabilization technique for cascaded systems in DC microgrids[J]. IEEE Transactions on Energy Conversion, 2021, 36(3): 1883-1895.
[14] Jiang Y X, Tian Y J, Li Y G, et al.DC-side current compensation control in the rectifier terminal for power variations in back-to-back converters[J]. IET Renewable Power Generation, 2021, 15(13): 3025-3037.
[15] 高娟, 秦岭. 虚拟同步发电机的输入阻抗建模及稳定性分析[J]. 电网技术, 2021, 45(2): 578-586.
Gao J, Qin L.Input impedance modeling and stability analysis for virtual synchronous generator[J]. Power System Technology, 2021, 45(2): 578-586.
[16] 姜玉霞, 田艳军, 李永刚. 背靠背变流器调节器参数及传输功率变化对阻抗稳定特性的影响及其改进控制策略[J]. 高电压技术, 2019, 45(9): 2866-2875.
Jiang Y X, Tian Y J, Li Y G.Influence of back-to-back converter regulator parameters and transmission power variation on impedance stability and improved control strategy[J]. High Voltage Engineering, 2019, 45(9): 2866-2875.
[17] Liu C R, Lai J S.Low frequency current ripple reduction technique with active control in a fuel cell power system with inverter load[J]. IEEE Transactions on Power Electronics, 2007, 22(4): 1429-1436.
[18] 祝国平, 阮新波, 王学华, 等. 两级式单相逆变器二次纹波电流的抑制与动态特性的改善[J]. 中国电机工程学报, 2013, 33(12): 72-80.
Zhu G P, Ruan X B, Wang X H, et al.Suppression of the second harmonic current and improvement of the dynamic performance for two-stage single-phase inverters[J]. Proceedings of the CSEE, 2013, 33(12): 72-80.
[19] 徐德鸿. 电力电子系统建模及控制[M]. 北京: 机械工业出版社, 2006.
Xu D H.Modeling and control of power electronic system[M]. Beijing: China Machine Press, 2006.
[20] Zhang X, Ruan X B, Kim H, et al.Adaptive active capacitor converter for improving stability of cascaded DC power supply system[J]. IEEE Transactions on Power Electronics, 2013, 28(4): 1807-1816.
PDF(4884 KB)
