Abstract：The medium-voltage DC power system has broad application prospects in new energy, rail transportation, and integrated power system for ships. As the connection channel between a medium-voltage DC network and a low-voltage AC network, a medium-voltage high-capacity inverter power supply undertakes the task of supplying power for daily use and auxiliary equipment, which needs to meet the requirements of power quality, efficiency, power density, and reliability. The MW-level inverter power supply has a low switching frequency (500 Hz~2 kHz) due to the performance of existing mature medium-voltage high-capacity power electronics devices. The main challenge is to achieve high dynamic response capability at a low switching frequency. This paper focuses on the refinement model, characterization, control parameter optimization, and other related research work under the application of multisampling techniques for medium-voltage DC inverter power supplies. Firstly, a state-space averaging model is established for the main circuit topology of the combined inverter and verified in the time domain. On this basis, a closed-loop control strategy containing double-closed-loop PI, feedforward decoupling, and active damping is adopted for the functional and index requirements of the inverter power supply in steady-state, dynamic, and grid-connected switching. A closed-loop state-space model under delay-free conditions is established to lay the foundation for the subsequent work. Secondly, the basic principle and the PWM model based on multisampling are introduced. The pure delay link is a transcendental equation, which is reduced to a finite-dimensional polynomial using the Pade approximation instead of the delay link. The system-level closed-loop model of the inverter considering multisampling is developed based on the Pade approximation. The effect of multisampling on the dynamic characteristics of the system is investigated by a single-axis equivalent model. The analysis results show that increasing sampling times can reduce the digital control delay, increase the system's closed-loop bandwidth, and reduce the step response overshoot. In this paper, the closed-loop bandwidth of a single sampling is 51.95 % of the delay-free model's bandwidth, while the closed-loop bandwidth of the system reaches 81.71 % of the bandwidth of the delay-free closed-loop model when the sampling times N is 5. Accordingly, a sampling number selection method is proposed that considers the bandwidth of the closed-loop system and the achievability of digital control. A 20 kW prototype platform is built to verify the correctness of the model and analysis results. Finally, according to the closed-loop model of the approximated inverter, the stability of the system is analyzed using the eigenvalue method, the sensitivity analysis of the PI control parameters to the eigenvalues is carried out, and the set of control parameters to be optimized is identified by sensitivity. Then, a mathematical model for control parameter optimization is established, and the final control parameters are obtained using a global optimization algorithm. In this paper, the closed-loop bandwidth of the optimized system is increased by 47.78 %, and the system's overshoot of the step response is reduced by 20.09 %. A 20 kW prototype platform verifies the effectiveness of the global optimization algorithm.
谢沁园, 王瑞田, 林克文, 范学鑫, 杨国润. 基于多次采样的中压大容量逆变电源建模及控制参数全局优化[J]. 电工技术学报, 2023, 38(14): 3849-3861.
Xie Qinyuan, Wang Ruitian, Lin Kewen, Fan Xuexin, Yang Guorun. Multisampling Based Modeling and Control of Medium-Voltage High-Power Inverter with Global Optimal Method. Transactions of China Electrotechnical Society, 2023, 38(14): 3849-3861.
[1] 马伟明. 电力电子在舰船电力系统中的典型应用[J].电工技术学报, 2011, 26(5): 1-7. Ma Weiming.Typical applications of power electro- nics in naval ship power systems[J]. Transactions of China Electrotechnical Society, 2011, 26(5): 1-7. [2] 马伟明. 关于电工学科前沿技术发展的若干思考[J]. 电工技术学报, 2021, 36(22): 4627-4636. Ma Weiming.Thoughts on the development of frontier technology in electrical engineering[J]. Transactions of China Electrotechnical Society, 2021, 36(22): 4627-4636. [3] 李科峰, 高山, 刘计龙, 等. 有源中点钳位五电平逆变器悬浮电容预充电控制策略[J]. 电工技术学报, 2022, 37(8): 2064-2075. Li Kefeng, Gao Shan, Liu Jilong, et al.Floating capacitor pre-charging control strategy for five-level active neutral-point-clamped inverter[J]. Transactions of China Electrotechnical Society, 2022, 37(8): 2064-2075. [4] 李倩倩, 夏蓉花, 刘战, 等. 有源中点钳位型三电平并网逆变器多目标优化预测控制[J]. 电气技术, 2021, 22(7): 13-18. Li Qianqian, Xia Ronghua, Liu Zhan, et al.Multi- objective optimal model predictive control for active neutral-point-clamped three-level inverter[J]. Electrical Engineering, 2021, 22(7): 13-18. [5] 曹文远, 韩民晓, 谢文强, 等. 交直流配电网逆变器并联控制技术研究现状分析[J]. 电工技术学报, 2019, 34(20): 4226-4241. Cao Wenyuan, Han Minxiao, Xie Wenqiang, et al.Analysis on research status of parallel inverters control technologies for AC/DC distribution net- work[J]. Transactions of China Electrotechnical Society, 2019, 34(20): 4226-4241. [6] 于彦雪, 马慧敏, 陈晓光, 等. 弱电网下基于准静态模型的混合控制微电网逆变器同步稳定性研究[J]. 电工技术学报, 2022, 37(1): 152-164. Yu Yanxue, Ma Huimin, Chen Xiaoguang, et al.Synchronous stability research of inverters in hybrid microgrid based on the quasi-static models under weak grid[J]. Transactions of China Electrotechnical Society, 2022, 37(1): 152-164. [7] 林霖, 裴忠晨, 蔡国伟, 等. 基于电力电子变压器的中压直流互联配电网协调控制方法[J]. 电力系统自动化, 2021, 45(8): 51-59. Lin Lin, Pei Zhongchen, Cai Guowei, et al.Coordinated control method for medium-voltage DC interconnected distribution network based on power electronic transformer[J]. Automation of Electric Power Systems, 2021, 45(8): 51-59. [8] 孙鹤旭, 李争, 陈爱兵, 等. 风电制氢技术现状及发展趋势[J]. 电工技术学报, 2019, 34(19): 4071-4083. Sun Hexu, Li Zheng, Chen Aibing, et al.Current status and development trend of hydrogen production technology by wind power[J]. Transactions of China Electrotechnical Society, 2019, 34(19): 4071-4083. [9] 孙孝峰, 张绘欣, 张涵, 等. 一种用于电-氢多能互补型微电网的双有源桥集成Boost拓扑及其控制[J].电工技术学报, 2021, 36(10): 2092-2104. Sun Xiaofeng, Zhang Huixin, Zhang Han, et al.Topology and control strategy of dual active bridge integrated boost circuit for electro-hydrogen multi- energy complementary microgrid[J]. Transactions of China Electrotechnical Society, 2021, 36(10): 2092-2104. [10] 郭小强, 魏玉鹏, 万燕鸣, 等. 新能源制氢电力电子变换器综述[J]. 电力系统自动化, 2021, 45(20): 185-199. Guo Xiaoqiang, Wei Yupeng, Wan Yanming, et al.Review on power electronic converters for producing hydrogen from renewable energy sources[J]. Auto- mation of Electric Power Systems, 2021, 45(20): 185-199. [11] 马伟明. 舰船动力发展的方向——综合电力系统[J].海军工程大学学报, 2002, 14(6): 1-5, 9. Ma Weiming.Integrated power systems—trend of ship power development[J]. Journal of Naval Univer- sity of Engineering, 2002, 14(6): 1-5, 9. [12] 张丹. 组合式多功能三相逆变器及其控制策略研究[D]. 马鞍山: 安徽工业大学, 2016. [13] 潘冬华, 阮新波, 王学华, 等. 提高LCL型并网逆变器鲁棒性的电容电流即时反馈有源阻尼方法[J]. 中国电机工程学报, 2013, 33(18): 1-10, 21. Pan Donghua, Ruan Xinbo, Wang Xuehua, et al.A real-time computation method with dual sampling modes to improve the current control performance of the LCL-type grid-connected inverter[J]. Proceedings of the CSEE, 2013, 33(18): 1-10, 21. [14] Zhang Xing, Chen Peng, Yu Changzhou, et al.Study of a current control strategy based on multisampling for high-power grid-connected inverters with an LCL filter[J]. IEEE Transactions on Power Electronics, 2017, 32(7): 5023-5034. [15] 周成, 江宏玲. 大功率并网逆变器多采样控制研究[J]. 大连交通大学学报, 2020, 41(3): 97-101. Zhou Cheng, Jiang Hongling.Research on multi- sampling control of high powergrid-connected inver- ter[J]. Journal of Dalian Jiaotong University, 2020, 41(3): 97-101. [16] Samanes J, Gubia E.Multisampled-capacitor-voltage active damping for parallel interleaved grid connected voltage source converters with LCL filter[C]//2017 19th European Conference on Power Electronics and Applications, Warsaw, Poland, 2017: 1-10. [17] Van de Sype D M, De Gusseme K, Van den Bossche A P, et al. Small-signal Laplace-domain analysis of uniformly-sampled pulse-width modulators[C]//IEEE 35th Annual Power Electronics Specialists Confer- ence, Aachen, Germany, 2004: 4292-4298. [18] Corradini L, Mattavelli P.Modeling of multisampled pulse width modulators for digitally controlled DC- DC converters[J]. IEEE Transactions on Power Elec- tronics, 2008, 23(4): 1839-1847. [19] 刘春喜, 陈鹏荣, 高姬, 等. 中频逆变器数字控制延时的线性化近似[J]. 电源学报, 2015, 13(3): 55-61. Liu Chunxi, Chen Pengrong, Gao Ji, et al.An approximation method of digital control delay in inverter[J]. Journal of Power Supply, 2015, 13(3): 55-61. [20] Liu Guangyuan, Mattavelli P.Hysteresis droop con- troller with one sample delay for DC-DC converters in DC microgrids[C]//IEEE Energy Conversion Congress and Exposition (ECCE), Baltimore, MD, USA, 2019: 2078-2084. [21] Fischer C, Mariéthoz S, Morari M.Multisampled hybrid model predictive control for pulse-width modulated systems[C]//IEEE Conference on Decision and Control and European Control Conference, Orlando, FL, USA, 2011: 3074-3079. [22] Tomlinson M, Mouton T, Kennel R.Finite-control-set model predictive control with a fixed switching frequency vs. linear control for current control of a single-leg inverter[C]//IEEE International Symposium on Predictive Control of Electrical Drives and Power Electronics, Valparaiso, Chile, 2016: 109-114. [23] 熊连松, 刘小康, 卓放, 等. 光伏发电系统的小信号建模及其控制器参数的全局优化设计方法[J]. 电网技术, 2014, 38(5): 1234-1241. Xiong Liansong, Liu Xiaokang, Zhuo Fang, et al.Small-signal modeling of photovoltaic power gen- eration system and global optimal design for its controller parameters[J]. Power System Technology, 2014, 38(5): 1234-1241. [24] 陈鹏. 基于多采样的大功率并网逆变器控制研究[D]. 合肥: 合肥工业大学, 2016. [25] Nolan P J, Sinha N K, Alden R T H. Eigenvalue sensitivities of power systems including network and shaft dynamics[J]. IEEE Transactions on Power Apparatus and Systems, 1976, 95(6): 1318-1324.
2023, Vol. 38 
