Novel Autonomous Power Balance Control for PMSG Based Wind Turbine in Stand Alone Operation
Lu Qiuyu1, Dai Yaohui2, Yang Yinguo1, Han Jinlong2, Liao Peng1
1. Electric Power Dispatching and Control Center of Guangdong Power Grid Corporation Guangzhou 510600 China; 2. School of Electrical Engineering Xi'an Jiaotong University Xi'an 710049 China;
Abstract：Recently, the permanent magnet synchronous generator-based wind turbine (PMSG-based WT) have gained significant popularity in wind power applications. With the development of microgrids, the PMSG-based WTs are required to be operated in the stand-alone operation mode in some scenarios. The previous studies in stand-alone microgrids mainly focus on the phase-locked loop (PLL)-based controls for WT, which still require the external grid-forming power supplies. The recent studies for the stand-alone operation of PLL-free WTs were relatively complicated and difficult to adjust the parameters. They did not adequately discuss the coordination of grid side converter (GSC) and rotor side converter (RSC) of WT, nor did they consider the demand response in stand-alone operation mode (SAOM). To bridge these gaps, this paper proposed two advanced autonomous power balance control schemes for PMSG-based WT in SAOM. In the first strategy, the GSC of WT controls the converter voltage as an ideal voltage source with the fixed modulation index and frequency, while the RSC of WT modifies the active power reference by controlling DC-link voltage through one PI controller. The main drawbacks of the first strategy are that the load demand response is not taken into consideration and it may not ensure the power synchronism of multi-WT in SAOM. Therefore, in the second strategy, the GSC of WT achieves grid-synchronization and inertia response utilizing the dynamic of DC-link voltage, while the RSC adjusts active power based on the DC-link voltage deviations to mimic the primary frequency control. Both proposed strategies can effectively ensure the independent operation of WT without PLL and external power supplies. Compared with the typical virtual synchronous generator (VSG) controls and other SAOM controls, the complexity of the proposed strategies is more reduced, and the control parameters are easy to tune, as they only require the measurement of DC-link voltage. Particularly, Strategy Ⅱ stands out by the energy-efficient property by using the reserved energy in DC capacitor for system inertia support and the load demand response to decrease the risks of WT tripping off. In order to improve the voltage profile of the second proposed scheme, an improved GSC control of WT via one simple PI controller for sustaining the point of common coupling (PCC) voltage during system disturbance is further proposed. Nonlinear simulations of one PMSG connected with several local loads considering various power system contingencies have been studied to verify the effectiveness of two proposed strategies. The following conclusions can be drawn from the simulation analysis: (1) Both strategies can effectively ensure the stable operation of PMSG-based WT in tested stand-alone system. (2) Strategy Ⅰ can well stabilize the grid frequency and the DC-link voltage. But it requires high operation costs of WT and is not energy-saving in SAOM. (3) Strategy Ⅱ makes the alternation of DC-link voltage proportional to the grid frequency, which reduces the power balance burden of stand-alone WT by temporally absorbing or releasing the energy from DC capacitor during load changes. More importantly, Strategy Ⅱ stands out by fully utilizing the load demand response for fast power balance and decreasing the risk of WT tripping, which is more energy-efficient and is suitable for multi-WTs operation in SAOM.
陆秋瑜, 戴耀辉, 杨银国, 韩金龙, 廖鹏. 适用于孤岛运行的永磁同步电机自动功率平衡控制策略研究[J]. 电工技术学报, 2023, 38(22): 6150-6164.
Lu Qiuyu1, Dai Yaohui2, Yang Yinguo1, Han Jinlong2, Liao Peng1. Novel Autonomous Power Balance Control for PMSG Based Wind Turbine in Stand Alone Operation. Transactions of China Electrotechnical Society, 2023, 38(22): 6150-6164.
[1] 马进, 赵大伟, 钱敏慧, 等. 大规模新能源接入弱同步支撑直流送端电网的运行控制技术综述[J]. 电网技术, 2017, 41(10): 3112-3120. Ma Jin, Zhao Dawei, Qian Minhui, et al.Reviews of control technologies of large-scale renewable energy connected to weakly-synchronized sending-end DC power grid[J]. Power System Technology, 2017, 41(10): 3112-3120. [2] Chang-Chien L R, Lin Weiting, Yin Y C. Enhancing frequency response control by DFIGs in the high wind penetrated power systems[J]. IEEE Transactions on Power Systems, 2011, 26(2): 710-718. [3] 吴恒, 阮新波, 杨东升. 弱电网条件下锁相环对LCL型并网逆变器稳定性的影响研究及锁相环参数设计[J]. 中国电机工程学报, 2014, 34(30): 5259-5268. Wu Heng, Ruan Xinbo, Yang Dongsheng.Research on the stability caused by phase-locked loop for LCL-type grid-connected inverter in weak grid condition[J]. Proceedings of the CSEE, 2014, 34(30): 5259-5268. [4] Li Yujun, Xu Zhao, Østergaard J, et al.Coordinated control strategies for offshore wind farm integration via VSC-HVDC for system frequency support[J]. IEEE Transactions on Energy Conversion, 2017, 32(3): 843-856. [5] 王盼宝, 王卫, 孟尼娜, 等. 直流微电网离网与并网运行统一控制策略[J]. 中国电机工程学报, 2015, 35(17): 4388-4396. Wang Panbao, Wang Wei, Meng Nina, et al.Unified control strategy of islanding and grid-connected operations for DC microgrid[J]. Proceedings of the CSEE, 2015, 35(17): 4388-4396. [6] Svensson J.Grid-connected voltage source converter[D]. Gothenburg: Chalmers University Technol, 1998. [7] Fischer P.Modelling and control of a line-commutated HVDC transmission system interacting with a VSC STATCOM[D]. Stockholm: Royal Institute of Technology, 2007. [8] Li Shuhui, Haskew T A, Swatloski R P, et al.Optimal and direct-current vector control of direct-driven PMSG wind turbines[J]. IEEE Transactions on Power Electronics, 2012, 27(5): 2325-2337. [9] Zhang Lidong, Harnefors L, Nee H P.Modeling and control of VSC-HVDC links connected to island systems[J]. IEEE Transactions on Power Systems, 2011, 26(2): 783-793. [10] Egea-Alvarez A, Fekriasl S, Hassan F, et al.Advanced vector control for voltage source converters connected to weak grids[J]. IEEE Transactions on Power Systems, 2015, 30(6): 3072-3081. [11] Wen Bo, Boroyevich D, Burgos R, et al.Analysis of D-Q small-signal impedance of grid-tied inverters[J]. IEEE Transactions on Power Electronics, 2016, 31(1): 675-687. [12] Kayikci M, Milanovic J V.Dynamic contribution of DFIG-based wind plants to system frequency disturbances[J]. IEEE Transactions on Power Systems, 2009, 24(2): 859-867. [13] Li Yujun, Xu Zhao, Wong K P.Advanced control strategies of PMSG-based wind turbines for system inertia support[J]. IEEE Transactions on Power Systems, 2017, 32(4): 3027-3037. [14] 颜湘武, 贾焦心, 王德胜, 等. 基于P/ω“导纳”的并联虚拟同步机功频响应建模与分析[J]. 电工技术学报, 2020, 35(15): 3191-3202. Yan Xiangwu, Jia Jiaoxin, Wang Desheng, et al.Modeling and analysis of active power-frequency response of parallel VSGs using a P/ω “admittance”[J]. Transactions of China Electrotechnical Society, 2020, 35(15): 3191-3202. [15] 于彦雪, 关万琳, 陈晓光, 等. 基于序阻抗的虚拟同步机同步频率谐振现象[J]. 电工技术学报, 2022, 37(10): 2584-2595. Yu Yanxue, Guan Wanlin, Chen Xiaoguang, et al.Synchronous frequency resonance in virtual sychronous generator based on sequence-impedance[J]. Transactions of China Electrotechnical Society, 2022, 37(10): 2584-2595. [16] Liao Kai, He Zhengyou, Xu Yan, et al.A sliding mode based damping control of DFIG for interarea power oscillations[J]. IEEE Transactions on Sustainable Energy, 2017, 8(1): 258-267. [17] Zhang Lidong, Harnefors L, Nee H P.Power-synchronization control of grid-connected voltage-source converters[J]. IEEE Transactions on Power Systems, 2010, 25(2): 809-820. [18] Guan Minyuan, Pan Wulue, Zhang Jing, et al.Synchronous generator emulation control strategy for voltage source converter (VSC) stations[J]. IEEE Transactions on Power Systems, 2015, 30(6): 3093-3101. [19] 杨仁炘, 张琛, 蔡旭. 具有频率实时镜像和自主电网同步能力的风场-柔直系统控制方法[J]. 中国电机工程学报, 2017, 37(2): 496-506. Yang Renxin, Zhang Chen, Cai Xu.Control of VSC-HVDC with real-time frequency mirroring and self-synchronizing capability for wind farm integration[J]. Proceedings of the CSEE, 2017, 37(2): 496-506. [20] 杨仁炘, 施刚, 蔡旭. 海上全直流型风电场的电压源型控制[J]. 电工技术学报, 2018, 33(2): 546-557. Yang Renxin, Shi Gang, Cai Xu.Voltage source control of offshore all-DC wind farm[J]. Transactions of China Electrotechnical Society, 2018, 33(2): 546-557. [21] 伍兴煌, 魏强. 使用虚拟阻抗的虚拟同步机转子角下垂控制[J]. 电气技术, 2020, 21(3): 31-36, 58. Wu Xinghuang, Wei Qiang.Virtual synchronous machine rotor angle droop control using virtual reactance[J]. Electrical Engineering, 2020, 21(3): 31-36, 58. [22] 兰征, 刁伟业, 曾进辉, 等. 含异构微源孤岛微电网内虚拟同步发电机预同步控制策略[J]. 电力系统自动化, 2022, 46(19): 154-161. Lan Zheng, Diao Weiye, Zeng Jinhui, et al.Pre-synchronization control strategy of virtual synchronous generator in islanded microgrid with heterogeneous distributed generators[J]. Automation of Electric Power Systems, 2022, 46(19): 154-161. [23] 颜湘武, 崔森, 常文斐. 考虑储能自适应调节的双馈感应发电机一次调频控制策略[J]. 电工技术学报, 2021, 36(5): 1027-1039. Yan Xiangwu, Cui Sen, Chang Wenfei.Primary frequency regulation control strategy of doubly-fed induction generator considering supercapacitor SOC feedback adaptive adjustment[J]. Transactions of China Electrotechnical Society, 2021, 36(5): 1027-1039. [24] Wu Dan, Tang Fen, Dragicevic T, et al.Autonomous active power control for islanded AC microgrids with photovoltaic generation and energy storage system[J]. IEEE Transactions on Energy Conversion, 2014, 29(4): 882-892. [25] Le H T, Santoso S, Nguyen T Q.Augmenting wind power penetration and grid voltage stability limits using ESS: application design, sizing, and a case study[J]. IEEE Transactions on Power Systems, 2012, 27(1): 161-171. [26] Kim J, Lee S H, Park J W.Inertia-free stand-alone microgrid—part Ⅱ: inertia control for stabilizing DC-link capacitor voltage of PMSG wind turbine system[J]. IEEE Transactions on Industry Applications, 2018, 54(5): 4060-4068.
2023, Vol. 38 
