Abstract:The voltage closed-loop control based on the PI regulator is generally adopted in the inde- pendent excitation DC power generation system. PI control can ensure the steady-state control accuracy of the system output voltage. However, limited by the fixed PI regulator parameters and the system’s nonlinearity, the dynamic regulation characteristics of the output voltage may have problems such as slow response speed and extensive voltage recovery overshooting when the system faces load mutation under different working conditions. In recent years, predictive control has been widely used in power electronics with its characteristics of fast dynamic response and strong resistance to disturbance. Among them, the generalized predictive control (GPC) based on multi-step prediction has the characteristics of high flexibility in parameter design and strong robustness when the prediction length is sufficient. As an alternative to PI control, it can improve the dynamic voltage performance of the system under load disturbance. Introducing load current feedforward is a standard method to solve the problem of the poor dynamic performance of PI control. Considering that the relation curve between excitation and load of the power generation system is coupled with the parameter of generator speed, the fitting function relation surface of excitation, load, and speed is constructed. After adding the feedback value of load current to the total generalized predicted output, the excitation current command value is obtained through the fitting function. The control loop of the system is approximately linearized by the fitting function, and the transfer function in the discrete domain of the control system is constructed to analyze the system's stability and ability to resist load disturbance. The system’s stability is judged by the closed-loop pole position in the discrete domain. When the weight coefficient r of the performance index function is small, the system is unstable. When the predicted length N, the weight factor RF, and the estimated capacitance value C of the load end change within a specific range, the closed-loop pole trajectory of the control system always lies in the unit circle, and the system is stable. The control parameters used in the final experiment are determined by analyzing anti-load disturbance ability. The smaller r value and more considerable N value can give the system more excellent anti-disturbance ability. However, Considering the limited computing power of the MCU in the interrupt cycle, the N value must be manageable in the experiment. Comparing the proposed GPC method with the PI method, the steady-state experiment, load disturbance dynamic experiment, and control algorithm complexity experiment are carried out, respectively. Finally, according to the experimental results, the following conclusions are drawn: (1) The GPC method based on the fitting function relationship can realize the closed-loop voltage control of the system with enough control accuracy when the speed changes. (2) Compared with the PI control method, the DC power generation system under the control of GPC has a significantly improved dynamic performance in the face of different load mutations. (3) When the prediction length of GPC is considerable, the MCU space and computing time required by the GPC algorithm are larger than the simple PI control.
夏宇航, 王宇, 陈凯, 张成糕. 独立励磁直流发电系统的广义预测电压控制策略[J]. 电工技术学报, 2023, 38(12): 3199-3207.
Xia Yuhang, Wang Yu, Chen Kai, Zhang Chenggao. Generalized Predictive Voltage Control Strategy for Independent Excitation DC Power Generation System. Transactions of China Electrotechnical Society, 2023, 38(12): 3199-3207.
[1] Patin N, Vido L, Monmasson E, et al.Control of a hybrid excitation synchronous generator for aircraft applications[J]. IEEE Transactions on Industrial Elec-tronics, 2008, 55(10): 3772-3783. [2] 甘志伟, 缪冬敏, 王云冲, 等. 宽转速范围永磁同步发电机系统稳压控制及参数优化[J]. 电工技术学报, 2020, 35(8): 1624-1633. Gan Zhiwei, Miao Dongmin, Wang Yunchong, et al.Voltage stabilization control and parameters opti-mization for wide-speed-range permanent magnet synchronous generator systems[J]. Transactions of China Electrotechnical Society, 2020, 35(8): 1624-1633. [3] 付兴贺, 江政龙, 吕鸿飞, 等. 电励磁同步电机无刷励磁与转矩密度提升技术发展综述[J]. 电工技术学报, 2022, 37(7): 1689-1702. Fu Xinghe, Jiang Zhenglong, Lü Hongfei, et al.Review of the blushless excitation and torque density improvement in wound field synchronous motors[J]. Transactions of China Electrotechnical Society, 2022, 37(7): 1689-1702. [4] Gao Fei, Bozhko S, Costabeber A, et al.Control design and voltage stability analysis of a droop-controlled electrical power system for more electric aircraft[J]. IEEE Transactions on Industrial Elec-tronics, 2017, 64(12): 9271-9281. [5] Wang Yu, Deng Zhiquan.Hybrid excitation topo-logies and control strategies of stator permanent magnet machines for DC power system[J]. IEEE Transactions on Industrial Electronics, 2012, 59(12): 4601-4616. [6] Vazquez S, Rodriguez J, Rivera M, et al.Model predictive control for power converters and drives: advances and trends[J]. IEEE Transactions on Indu-strial Electronics, 2017, 64(2): 935-947. [7] 齐昕, 苏涛, 周珂, 等. 交流电机模型预测控制策略发展概述[J]. 中国电机工程学报, 2021, 41(18): 6408-6419. Qi Xin, Su Tao, Zhou Ke, et al.Development of AC motor model predictive control strategy: an over-view[J]. Proceedings of the CSEE, 2021, 41(18): 6408-6419. [8] Zhang Xiuyun, Shi Tingna, Wang Zhiqiang, et al.Generalized predictive contour control of the biaxial motion system[J]. IEEE Transactions on Industrial Electronics, 2018, 65(11): 8488-8497. [9] Choi D K, Lee K B.Dynamic performance improve-ment of AC/DC converter using model predictive direct power control with finite control set[J]. IEEE Transactions on Industrial Electronics, 2015, 62(2): 757-767. [10] 卜飞飞, 罗捷, 刘皓喆, 等. 双绕组感应发电机系统无差拍电流预测控制策略[J]. 电工技术学报, 2021, 36(24): 5213-5224. Bu Feifei, Luo Jie, Liu Haozhe, et al.Deadbeat predictive current control strategy of dual winding induction generator system[J]. Transactions of China Electrotechnical Society, 2021, 36(24): 5213-5224. [11] 徐伟, 陈俊杰, 刘毅, 等. 无刷双馈独立发电系统的改进无参数预测电流控制[J]. 电工技术学报, 2021, 36(19): 4002-4015. Xu Wei, Chen Junjie, Liu Yi, et al.Improved nonparametric predictive current control for standalone brushless doubly-fed induction generators[J]. Transa-ctions of China Electrotechnical Society, 2021, 36(19): 4002-4015. [12] 肖蕙蕙, 魏苏东, 郭强, 等. 优化开关序列的PWM整流器模型预测控制策略[J]. 电工技术学报, 2022, 37(14): 3665-3675, 3700. Xiao Huihui, Wei Sudong, Guo Qiang, et al.Model predictive control strategy for PWM rectifier with optimized switching sequence[J]. Transactions of China Electrotechnical Society, 2022, 37(14): 3665-3675, 3700. [13] Wang Tao, Zhu Z Q, Freire N M A, et al. Generalized predictive DC-link voltage control for grid-connected converter[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2022, 10(2): 1489-1506. [14] 王莉, 曹小庆, 张卓然, 等. 电励磁双凸极无刷直流发电机非线性PI调压技术的研究[J]. 中国电机工程学报, 2006, 26(5): 153-158. Wang Li, Cao Xiaoqing, Zhang Zhuoran, et al.Research of nonlinear PI voltage regulation for doubly salient brushless DC generator[J]. Proceedings of the CSEE, 2006, 26(5): 153-158. [15] Xu Yanwu, Zhang Zhuoran, Bian Zhangming, et al.Capacitor-energy-based control of doubly salient brushless DC generator for dynamic performance optimization[J]. IEEE Transactions on Energy Con-version, 2020, 35(4): 1886-1896. [16] 翟小飞, 马伟明, 欧阳斌, 等. 前馈控制在脉冲整流发电机数字励磁控制系统中的应用[J]. 电工技术学报, 2013, 28(7): 151-156. Zhai Xiaofei, Ma Weiming, Ouyang Bin, et al.Application of feed forward control in the excitation system of pulse rectified generator[J]. Transactions of China Electrotechnical Society, 2013, 28(7): 151-156. [17] 赵耀, 王慧贞, 张海波, 等. 基于励磁电流前馈调节的航空直流发电系统建模分析[J]. 航空学报, 2015, 36(4): 1230-1239. Zhao Yao, Wang Huizhen, Zhang Haibo, et al.Modeling and analysis of aero DC generation system based on excitation current feedforward regulation[J]. Acta Aeronauticaet Astronautica Sinica, 2015, 36(4): 1230-1239. [18] 刘金利, 马伟明, 翟小飞, 等. 带脉冲负载多相储能发电机励磁控制系统设计[J]. 海军工程大学学报, 2019, 31(3): 32-38. Liu Jinli, Ma Weiming, Zhai Xiaofei, et al.Design of excitation control system for multi-phase energy storage generator with pulse load[J]. Journal of Naval University of Engineering, 2019, 31(3): 32-38. [19] 阳习党, 翟小飞, 马伟明, 等. 整流充电发电机组励磁系统[J]. 电工技术学报, 2014, 29(5): 54-61. Yang Xidang, Zhai Xiaofei, Ma Weiming, et al.Excitation system of rectified charging generators[J]. Transactions of China Electrotechnical Society, 2014, 29(5): 54-61. [20] Jury E, Gutman S.On the stability of the Amatrix inside the unit circle[J]. IEEE Transactions on Auto-matic Control, 1975, 20(4): 533-535.