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| A Phase-Locked Loop Parameter Design Method Based on Current Stable Operation Domain of Grid-Connected Converter |
| Zheng Yuting1, Xiao Fan1, Xie Weijie1, Tu Chunming1, Fan Dingzhong2 |
1. National Electric Power Conversion and Control Engineering Technology Research Center Hunan University Changsha 410082 China;
2. State Grid Xiangtan Power Supply Company Xiangtan 411100 China |
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Abstract Traditional control parameter design methods of grid-connected converters (GCCs) are usually carried out under rated operation conditions. The stability margin is generally characterized by the magnitude margin (GM) and phase margin (PM). The bandwidth of the phase-locked loop (PLL) needs to be sacrificed for enough system stability margin, which ensures that the system can operate safely under non-rated working conditions. Therefore, traditional parameter design methods make it difficult to achieve a compromise between the stability and rapidity of GCC. Furthermore, the relationship between the stability margin and the output limit of the system is difficult to obtain, which relies on simulations or experiments. To address this issue, this paper proposes a control parameter design method based on the system stable operation domain, which com- prehensively considers the variable working conditions and different stability requirements.
Firstly, the complex vector open-loop transfer function Gs(s) is derived, which can analyze the stability of the system in a wide operating range or under different parameters. Secondly, varying the values of the PLL and current loop control parameters, the feasible domain of control parameters can be obtained by numerical analysis. PLL and current loop are coupled to each other due to the grid impedance. Therefore, the phase-locked loop parameter has a stable parameter boundary. Thirdly, based on the upper limit of the obtained PLL parameter, the three-dimensional diagram between the PLL parameter and the output current of the dq-axis is plotted, which shows the stable operation boundaries of GCC under different PLL parameters. Finally, taking the operation margin as the stability margin, the PLL parameter can be flexibly designed to realize the balance between the stability margin and the dynamic performance. Theoretical analysis results show that the control parameter design method based on the stable domain can ensure the safe and reliable operation of the system. Compared with traditional parameter design methods, determining the value of control parameter based on operation margin can improve the dynamic performance of PLL. At the same time, the corresponding relationship between different stability margin and the output current limit of the system can be obtained. Finally, the simulation and experiment results verify the correctness of the theoretical analysis and the effectiveness of the proposed design method.
The following conclusions can be drawn from the theoretical analyses: (1) The derived open-loop complex transfer function can be used to plot the control parameter feasible domain and the stable operation domain of GCC. The PLL control parameter satisfying the operation margin can be obtained quickly without repeated trial and error in the parameter design. (2) The analysis results show that the grid strength is positively correlated with the parameter feasible domain and the PLL cutoff frequency is negatively correlated with the stable operation domain. The cutoff frequency value of PLL is limited by the current loop parameter. The smaller the operating current in the parameter design, the wider the range of PLL cutoff frequency, and the better the dynamic performance of the PLL. (3) The control parameter design method based on the stable operation domain can directly quantify the influence of stability margin on the limit of the output current, which can be used for obtaining the stable boundaries under different stability margin. At the same time, the control parameters of PLL can be flexibly designed according to the actual needs of rapidity.
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Received: 28 February 2024
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[1] 潘超, 范宫博, 王锦鹏, 等. 灵活性资源参与的电热综合能源系统低碳优化[J]. 电工技术学报, 2023, 38(6): 1633-1647.
Pan Chao, Fan Gongbo, Wang Jinpeng, et al.Low- carbon optimization of electric and heating integrated energy system with flexible resource participation[J]. Transactions of China Electrotechnical Society, 2023, 38(6): 1633-1647.
[2] 高锋阳, 宋志翔, 高建宁, 等. 计及光伏和储能接入的牵引供电系统能量管理策略[J]. 电工技术学报, 2024, 39(3): 745-757.
Gao Fengyang, Song Zhixiang, Gao Jianning, et al.Energy management strategies for traction power systems with PV and energy storage access[J]. Transactions of China Electrotechnical Society, 2024, 39(3): 745-757.
[3] 高家元, 黄帅, 姜飞, 等. 弱电网下基于比例权重的控制环参数自适应调整并网逆变器稳定性提升方法[J]. 电工技术学报, 2024, 39(24): 7846-7859.
Gao Jiayuan, Huang Shuai, Jiang Fei, et al.Stability improvement method of grid-connected inverter based on proportional weight control loop parameters adaptive adjustment under weak grid[J]. Transactions of China Electro- technical Society, 2024, 39(24): 7846-7859.
[4] 曾祥辰, 刘青, 王嘉晨, 等. 弱电网下并网逆变器恒定带宽及稳定裕度的自适应控制策略[J]. 电工技术学报, 2024, 39(9): 2682-2695.
Zeng Xiangchen, Liu Qing, Wang Jiachen, et al.Adaptive control strategy of grid-connected inverters with constant bandwidth and stability margin in weak grids[J]. Transactions of China Electrotechnical Society, 2024, 39(9): 2682-2695.
[5] 高磊, 吕敬, 马骏超, 等. 基于电路等效的并网逆变器失稳分析与稳定控制[J]. 电工技术学报, 2024, 39(8): 2325-2341.
Gao Lei, LüJing, Ma Junchao, et al. Instability analysis and stability control of grid-connected inverter based on impedance circuit equivalent[J]. Transactions of China Electrotechnical Society, 2024, 39(8): 2325-2341.
[6] 韩应生, 孙海顺, 秦世耀, 等. 电压源型双馈风电并网系统小扰动低频稳定性分析[J]. 电工技术学报, 2023, 38(5): 1312-1324, 1374.
Han Yingsheng, Sun Haishun, Qin Shiyao, et al.Low-frequency stability analysis of voltage-sourced doubly-fed wind power grid-connected system under small disturbance[J]. Transactions of China Electro- technical Society, 2023, 38(5): 1312-1324, 1374.
[7] 刘昊, 方天治, 张惠丽, 等. 弱电网下应对复杂稳定性问题的并网逆变器改进电压前馈通路研究[J]. 电工技术学报, 2024, 39(16): 4955-4967.
Liu Hao, Fang Tianzhi, Zhang Huili, et al.Research on an improved voltage feedforward path of grid- connected inverter coping with complex stability issues in weak grid[J]. Transactions of China Elec- trotechnical Society, 2024, 39(16): 4955-4967.
[8] 杨苓, 陈燕东, 周乐明, 等. 弱电网下锁相环对三相LCL型并网逆变器小扰动建模影响及稳定性分析[J]. 中国电机工程学报, 2018, 38(13): 3792-3804, 4020.
Yang Ling, Chen Yandong, Zhou Leming, et al.Effect of phase locked loop on the small-signal perturbation modeling and stability analysis for three-phase LCL-type grid-connected inverter in weak grid[J]. Proceedings of the CSEE, 2018, 38(13): 3792-3804, 4020.
[9] 杨明, 杨倬, 李玉龙, 等. 高渗透率下基于并网逆变器阻抗重塑的锁相环设计方法[J]. 电工技术学报, 2024, 39(2): 554-566.
Yang Ming, Yang Zhuo, Li Yulong, et al.A phase-locked loop design method based on impedance remodeling of grid-connected inverter under high permeability[J]. Transactions of China Electro- technical Society, 2024, 39(2): 554-566.
[10] 张亚楠, 杨兴武, 徐常天. 基于环路滤波阻抗重塑的并网锁相环改进方法[J]. 电力电子技术, 2023, 57(11): 81-84.
Zhang Yanan, Yang Xingwu, Xu Changtian.Improved method of grid-connected phase-locked loop based on loop filtering impedance remodeling[J]. Power Electronics, 2023, 57(11): 81-84.
[11] 高家元, 涂春鸣, 肖凡, 等. 弱电网下基于SISO阻抗模型的LCL滤波并网逆变器在不同域下的稳定性差异分析[J]. 中国电机工程学报, 2022, 42(18): 6777-6788.
Gao Jiayuan, Tu Chunming, Xiao Fan, et al.Analysis of stability differences of LCL-filter grid-connected inverters in different domains based on SISO impedance model in weak grids[J]. Proceedings of the CSEE, 2022, 42(18): 6777-6788.
[12] 韩以鑫, 邹复民, 侯隽, 等. 两相静止坐标系下基于改进型双二阶广义积分器的锁相环控制策略[J]. 电气技术, 2024, 25(1): 23-33.
Han Yixin, Zou Fumin, Hou Jun, et al.Phase-locked loop control strategy based on improved dual second-order generalized integrator in two-phase stationary coordinate system[J]. Electrical Engin- eering, 2024, 25(1): 23-33.
[13] 周立, 刘一鸣, 刘金澍, 等. 零相位滑动平均滤波器锁相环在LCL型逆变器中的应用[J]. 电气工程学报, 2023, 18(1): 68-76, 85.
Zhou Li, Liu Yiming, Liu Jinshu, et al.Application of zero phase moving average filter in LCL inverter[J]. Journal of Electrical Engineering, 2023, 18(1): 68-76, 85.
[14] Sevilmiş F, Karaca H.Implementation of enhanced non-adaptive cascaded DSC-PLLs for renewable energy systems[J]. International Journal of Electrical Power & Energy Systems, 2022, 134: 107470.
[15] 张学广, 伏思达, 付志超, 等. 弱电网下基于电压扰动补偿的并网变换器改进控制方法[J]. 电力系统自动化, 2019, 43(18): 137-144.
Zhang Xueguang, Fu Sida, Fu Zhichao, et al.Improved control method of grid-connected converter based on voltage disturbance compensation in weak grid[J]. Automation of Electric Power Systems, 2019, 43(18): 137-144.
[16] Zhang Xueguang, Fu Sida, Chen Wenjia, et al.A symmetrical control method for grid-connected con- verters to suppress the frequency coupling under weak grid conditions[J]. IEEE Transactions on Power Electronics, 2020, 35(12): 13488-13499.
[17] Zhang Xueguang, Xia Danni, Fu Zhichao, et al.An improved feedforward control method considering PLL dynamics to improve weak grid stability of grid-connected inverters[J]. IEEE Transactions on Industry Applications, 2018, 54(5): 5143-5151.
[18] Turner R, Walton S, Duke R.Robust high- performance inverter control using discrete direct- design pole placement[J]. IEEE Transactions on Industrial Electronics, 2011, 58(1): 348-357.
[19] Dannehl J, Fuchs F W, Thøgersen P B.PI state space current control of grid-connected PWM converters with LCL filters[J]. IEEE Transactions on Power Electronics, 2010, 25(9): 2320-2330.
[20] 黄现莲, 冯向东. 增强变流器对电网阻抗适应性的陷波前馈控制[J]. 电气传动, 2017, 47(10): 24-28.
Huang Xianlian, Feng Xiangdong.Notch filter based grid-voltage feedforward control for enhancing grid- connected converter’s adaptive capacity to grid impe- dance variation[J]. Electric Drive, 2017, 47(10): 24-28.
[21] 黄伟煌, 李明, 郭铸, 等. 基于小干扰稳定性的多端混合高压直流输电系统控制参数分析与优化方法[J]. 电网技术, 2020, 44(8): 2941-2949.
Huang Weihuang, Li Ming, Guo Zhu, et al.Control parameter analysis and optimization method of multi-terminal hybrid HVDC transmission system based on small signal stability[J]. Power System Technology, 2020, 44(8): 2941-2949.
[22] 李明, 张兴, 郭梓暄, 等. 弱电网下基于D分割法的逆变器PI参数设计及稳定域分析[J]. 电力系统自动化, 2020, 44(15): 139-147.
Li Ming, Zhang Xing, Guo Zixuan, et al.Proportional-integral parameter design for inverter based on D-partition method and its stability region analysis in weak grid[J]. Automation of Electric Power Systems, 2020, 44(15): 139-147.
[23] Zhu Donghai, Zhou Shiying, Zou Xudong, et al.Improved design of PLL controller for LCL-type grid-connected converter in weak grid[J]. IEEE Transactions on Power Electronics, 2020, 35(5): 4715-4727.
[24] Li Xing, Lin Hua.A design method of phase-locked loop for grid-connected converters considering the influence of current loops in weak grid[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 8(3): 2420-2429.
[25] 谢伟杰, 肖凡, 涂春鸣, 等. 考虑工作点时变特性的并网变流器全工作区间稳定性分析[J]. 中国电机工程学报, 2024, 44(7): 2801-2815.
Xie Weijie, Xiao Fan, Tu Chunming, et al.Full working area stability analysis of grid-connected converters considering time-varying characteristics of operating points[J]. Proceedings of the CSEE, 2024, 44(7): 2801-2815.
[26] 夏杨红, 孙勇, 韦巍. 光伏接入直流配电网时的功率振荡分析[J]. 中国电机工程学报, 2018, 38(23): 6814-6824.
Xia Yanghong, Sun Yong, Wei Wei.Power oscillation analysis of PV generators connected to DC dis- tribution network[J]. Proceedings of the CSEE, 2018, 38(23): 6814-6824.
[27] Burgos-Mellado C, Costabeber A, Sumner M, et al.Small-signal modelling and stability assessment of phase-locked loops in weak grids[J]. Energies, 2019, 12(7): 1227.
[28] Holmes D G, Lipo T A, McGrath B P, et al. Optimized design of stationary frame three phase AC current regulators[J]. IEEE Transactions on Power Electronics, 2009, 24(11): 2417-2426.
[29] Chung S K.A phase tracking system for three phase utility interface inverters[J]. IEEE Transactions on Power Electronics, 2000, 15(3): 431-438. |
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2025, Vol. 40 
