High Power Factor Control Strategy for Electrolytic Capacitor-Free Drive System Based on Grid Current Feedforward Compensation
Zhang Xiaojun1, Huang Wanben2, Situ Anqi3, Kang Min1, Yang Jiaqiang3
1. School of Automation Electrical Engineering Zhejiang University of Science and Technology Hangzhou 310023 China; 2. State Grid Zhejiang Electric Power Co. Ltd Wenzhou Power Supply Company Wenzhou 325000 China; 3. School of Electrical Engineering Zhejiang University Hangzhou 310027 China
Abstract：The capacitor-less compressor drive system employs small-capacity film capacitors while eliminating the power factor correction circuit, significantly enhancing system integration, operational reliability, and lifecycle. While replacing large electrolytic capacitors with small-value DC-bus film capacitors reduces costs and minimizes the physical footprint, the reduced DC-side capacitance increases coupling between the grid-side and motor-side energy, leading to increased grid-side current harmonics and a diminished system power factor. Traditional control strategies typically employ grid-side current differentiation and observer methods. However, current differentiation amplifies signal noise, potentially compromising system stability. Concurrently, the observer approach necessitates parameter design, increasing the complexity of system algorithms. This paper proposes a strategy based on current feedforward compensation. First, the power coupling between the DC bus front-end and back-end stages and the grid current harmonic power is modeled. Subsequently, an indirect differential model of the grid current is established to extract and compensate for grid current harmonics. The proposed method can obtain the rate of change of the grid current without directly measuring it, thereby avoiding error amplification that would result from directly differentiating the grid current. Additionally, a method for selecting compensation coefficients is provided to meet system stability and steady-state performance requirements. The experiment is conducted using a 750 W air-conditioner compressor. Compared with inverter-based power control and PR control, the proposed method achieves the highest sinusoidal waveform quality for the grid-side current, the lowest harmonic content, and the highest power factor of 0.99, meeting IEC 61000-3-2 standards. Tests at 1 000 W confirm that the proposed algorithm maintains excellent performance, with the power factor sustained at 0.99. The following conclusions can be drawn. (1) By utilizing grid voltage and bus voltage information to calculate the grid current rate of change, the error amplification issue caused by directly differentiating the grid current is avoided. (2) By extracting grid-side harmonic currents and implementing feedforward compensation on the q-axis currents, precise control over inverter power output is achieved. (3) By considering both the system’s stability requirements and its steady-state performance, this paper establishes a feasible range for the compensation coefficient m. It ensures that the selected value simultaneously satisfies stability constraints, enhances resonance suppression, and meets overall steady-state performance requirements.
张晓军, 黄万奔, 司徒安祺, 康敏, 杨家强. 基于电网电流前馈补偿的无电解电容驱动系统网侧高功率因数控制策略[J]. 电工技术学报, 2026, 41(18): 6256-6267.
Zhang Xiaojun, Huang Wanben, Situ Anqi, Kang Min, Yang Jiaqiang. High Power Factor Control Strategy for Electrolytic Capacitor-Free Drive System Based on Grid Current Feedforward Compensation. Transactions of China Electrotechnical Society, 2026, 41(18): 6256-6267.
[1] 房钰超, 王博, 王元奎, 等. 基于动态零矢量脉宽调制的永磁同步电机相电流重构方法[J]. 电工技术学报, 2025, 40(14): 4483-4493. Fang Yuchao, Wang Bo, Wang Yuankui, et al.Phase current reconstruction method for permanent magnet synchronous motors based on active zero state pulse width modulation[J]. Transactions of China Electro- technical Society, 2025, 40(14): 4483-4493. [2] 王奇维, 李斌兴, 潘冠丞, 等. 基于转子位置误差解耦阻抗建模的永磁同步电机电感在线辨识方法[J]. 电工技术学报, 2025, 40(2): 439-451. Wang Qiwei, Li Binxing, Pan Guancheng, et al.Impedance model based online inductance identi- fication method of permanent magnet synchronous motor decoupled from rotor position error[J]. Transactions of China Electrotechnical Society, 2025, 40(2): 439-451. [3] 兰志勇, 张丽雨, 李福, 等. 永磁同步电机控制技术综述[J]. 电气技术, 2025, 26(8): 1-10. Lan Zhiyong, Zhang Liyu, Li Fu, et al.Review of the control technologies of permanent magnet syn- chronous motor[J]. Electrical Engineering, 2025, 26(8): 1-10. [4] 鞠孝伟, 龙佳兴, 张凤阁, 等. 电动飞行汽车用推进电机发展现状和研究综述[J]. 电工技术学报, 2025, 40(17): 5402-5421. Ju Xiaowei, Long Jiaxing, Zhang Fengge, et al.Development status and research overview of propulsion motors for eVTOL[J]. Transactions of China Electrotechnical Society, 2025, 40(17): 5402-5421. [5] Huo Junya, Ding Dawei, Ren Zekun, et al.A novel flux-weakening control method with quadrature voltage constrain for electrolytic capacitorless PMSM drives[J]. CES Transactions on Electrical Machines and Systems, 2022, 6(3): 279-287. [6] 杨哲斌, 邓鎔峰, 张晓军, 等. 基于转矩跟踪电流误差校正的压缩机转速脉动抑制算法研究[J]. 电机与控制学报, 2024, 28(7): 13-23. Yang Zhebin, Deng Rongfeng, Zhang Xiaojun, et al.Research on speed ripple suppression algorithm of compressor motor based on torque tracking current error correction[J]. Electric Machines and Control, 2024, 28(7): 13-23. [7] Gao Runfeng, Ding Dawei, Wang Gaolin, et al.Feature extraction of frequency-mapping-based resonance suppression in PMSM drives with low DC-link capacitance and inductance[J]. IEEE Trans- actions on Power Electronics, 2025, 40(4): 4848-4861. [8] 赵楠楠, 周峰, 丁大尉, 等. 永磁电机无电解电容驱动系统网侧电流谐波抑制策略[J]. 中国电机工程学报, 2022, 42(3): 1145-1153. Zhao Nannan, Zhou Feng, Ding Dawei, et al.Suppression strategy of grid-side current harmonics for electrolytic capacitor-less permanent magnet motor drives[J]. Proceedings of the CSEE, 2022, 42(3): 1145-1153. [9] Deng Rongfeng, Yang Zhebin, Zhang Xiaojun, et al.A noninverse internal plant model-based cascade loop control structure for compressor drive with small film capacitor[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2024, 12(1): 862-875. [10] 陈前, 陈鑫, 颜黎浩, 等. 无电解电容五相永磁同步电机驱动系统主动阻尼控制策略[J]. 电气工程学报, 2023, 18(4): 106-113. Chen Qian, Chen Xin, Yan Lihao, et al.Active damping control strategy for five-phase permanent magnet synchronous motor drive system without electrolytic capacitors[J]. Journal of Electrical Engineering, 2023, 18(4): 106-113. [11] 林国庆, 黄远彬. 两开关无电解电容LED驱动电路拓扑及控制策略[J]. 电工技术学报, 2024, 39(18): 5742-5754. Lin Guoqing, Huang Yuanbin.Two-switch elec- trolytic capacitor-less LED driving circuit topology and control strategy[J]. Transactions of China Elec- trotechnical Society, 2024, 39(18): 5742-5754. [12] 王立乔, 陈建医, 程超然, 等. 单级单相无电解电容Buck-Boost逆变器[J]. 电工技术学报, 2023, 38(24): 6768-6781. Wang Liqiao, Chen Jianyi, Cheng Chaoran, et al.A single-stage single-phase Buck-Boost inverter without electrolytic capacitor[J]. Transactions of China Elec- trotechnical Society, 2023, 38(24): 6768-6781. [13] 丁大尉, 谢辉, 王高林, 等. 电网电压不平衡条件下永磁电机无电解电容驱动系统网侧电流谐波抑制方法[J]. 中国电机工程学报, 2025, 45(11): 4458-4468. Ding Dawei, Xie Hui, Wang Gaolin, et al.Suppression strategy of grid-side current harmonics for electrolytic capacitor-less permanent magnet motor drives under unbalanced grid voltage[J]. Proceedings of the CSEE, 2025, 45(11): 4458-4468. [14] 黄万奔, 杨家强, 邓鎔峰, 等. 高功率因数无电解电容永磁电机变频系统逆变器电流控制策略[J]. 电机与控制学报, 2022, 26(8): 1-10. Huang Wanben, Yang Jiaqiang, Deng Rongfeng, et al.Inverter current control strategy for high power factor electrolytic capacitor-less permanent magnet motor drive system[J]. Electric Machines and Control, 2022, 26(8): 1-10. [15] Inazuma K, Utsugi H, Ohishi K, et al.High- power-factor single-phase diode rectifier driven by repetitively controlled IPM motor[J]. IEEE Trans- actions on Industrial Electronics, 2013, 60(10): 4427-4437. [16] Zhao Nannan, Wang Gaolin, Xu Dianguo, et al.Inverter power control based on DC-link voltage regulation for IPMSM drives without electrolytic capacitors[J]. IEEE Transactions on Power Elec- tronics, 2018, 33(1): 558-571. [17] Son Y, Ha J I.Direct power control of a three-phase inverter for grid input current shaping of a single- phase diode rectifier with a small DC-link capa- citor[J]. IEEE Transactions on Power Electronics, 2015, 30(7): 3794-3803. [18] Deng Rongfeng, Zhang Xiaojun, Yang Zhebin, et al.Admittance reshaping based on adaptive minimum value of DC-link voltage for IPMSM drive with small film capacitor[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2023, 11(5): 5208-5221. [19] 宋健, 宋文祥, 张钦清. 直流母线小电容永磁同步电机驱动系统网侧电流谐波抑制策略[J]. 电工技术学报, 2024, 39(18): 5668-5679. Song Jian, Song Wenxiang, Zhang Qinqing.Harmonic suppression strategy of grid side current for DC-link small capacitor permanent magnet synchronous motor drive system[J]. Transactions of China Electro- technical Society, 2024, 39(18): 5668-5679. [20] Ren Zekun, Ding Dawei, Wang Gaolin, et al.Adaptive virtual admittance reshaping-based resonance suppression strategy for PMSM drives with small DC-link capacitor[J]. IEEE Transactions on Power Electronics, 2024, 39(3): 3109-3121. [21] 尹泉, 李海春, 罗慧, 等. 无电解电容永磁同步电机驱动系统谐振抑制[J]. 华中科技大学学报(自然科学版), 2021, 49(6): 1-6. Yin Quan, Li Haichun, Luo Hui, et al.Resonance suppression for electrolytic capacitor-less IPMSM drive system[J]. Journal of Huazhong University of Science and Technology (Nature Science Edition), 2021, 49(6): 1-6. [22] Wang Dong, Lu Kaiyuan, Rasmussen P O, et al.Voltage modulation using virtual positive impedance concept for active damping of small DC-link drive system[J]. IEEE Transactions on Power Electronics, 2018, 33(12): 10611-10621.
2026, Vol. 41 
