Abstract:Modeling and simulation of offshore wind power is the key supporting technology for building a new power system with new energy as the main body. As the core component of direct drive or semi-direct drive models, the existing models of permanent magnet synchronous generator (PMSG) have certain limitations: the grey box model provided by commercial software cannot be known about the modeling principle and are manifested in insufficient openness, which limits the application of efficient electromagnetic transient modeling algorithms and parallel acceleration algorithms for wind turbine units; The commonly used PMSG modeling method cannot generate interface and external circuit connections; PMSG is a kind of synchronous generator which has different order mathematical models, and the existing models are inconvenient to change. In order to solve the above problems, this paper proposes a permanent magnet synchronous generator equivalent model which has several advantages compared to existing models and can be applied to different scenarios. On the premise of meeting the accuracy, the model considers the adjustable order of the model, and is an integrated model that can directly connect external circuits. Firstly, starting from the synchronous motor equation, the voltage and flux equations of the generator are discretized, then analyze the algebraic loop problem in generator simulation. Secondly, reconstruct the PMSG model by applying a single step delay to the coupling variables to eliminate the algebraic loop. Thirdly, introduce Park transformation and use matrix block calculation methods to derive its Norton equivalent circuit, completing the construction of the model, and conduct applicability analysis of the method. Finally, based on the modeling method proposed and the usage methods of various code segments of the component tool Cbuilder on the RTDS simulation platform, construct an overall simulation framework for the model. The benchmark model of all components in RTDS and the test model of PMSG model with three orders are built. Then the test of multiple working conditions is carried out, including short circuit fault conditions at four different fault points, small disturbance condition and wind speed variation conditions. The results show that the fourth and second order models were found to be applicable for station level simulation, but they cannot accurately reflect the coupling characteristics between the generator and the machine side converter, as well as between the generator and the wind turbine. The sixth order model achieved high fitting of the benchmark model under multiple operating conditions, with an average relative error of less than 4%, which can simultaneously meet the simulation needs of both station level and internal units. In summary, this paper attempts to solve the limitations of existing PMSG models from the aspect of simulation modeling. For the simulation of offshore wind power, the equivalent model proposed in this paper can be flexibly adjusted and used according to different simulation objectives. The proposed method provides a PMSG model which istransparent and easy to program in simulation platformfor the application of efficient electromagnetic transient modeling methods in overall wind turbine modeling and parallel acceleration algorithms in offshore wind power simulation.
[1] 崔鹤松, 李雪萍, 黄晟, 等. 模块化多相永磁风力发电机串并联直流海上风电场电压协调控制[J]. 电工技术学报, 2023, 38(4): 925-935. Cui Hesong, Li Xueping, Huang Sheng, et al.Voltage coordinated control strategy for modular multi-phase pmsg-based series-parallel DC connected offshore wind farm[J]. Transactions of China Electrotechnical Society, 2023, 38(4): 925-935. [2] 迟永宁, 梁伟, 张占奎, 等. 大规模海上风电输电与并网关键技术研究综述[J]. 中国电机工程学报, 2016, 36(14): 3758-3770. Chi Yongning, Liang Wei, Zhang Zhankui, et al.An overview on key technologies regarding power transmission and grid integration of large scaleoffshore wind power[J]. Proceedings of the CSEE, 2016, 36(14): 3758-3770. [3] 杨培文, 李洪涛, 杨锡运, 等. 风电机组技术现状分析及未来发展趋势预测[J]. 电力电子技术, 2020, 54(3): 79-82. Yang Peiwen, Li Hongtao, Yang Xiyun, et al.Analysis of the present situation of wind turbine technology and forecast of future development trend[J]. Power Elctronics, 2020, 54(3): 79-82. [4] Gnanarathna U N, Gole A M, Jayasinghe R P.Efficient modeling of modular multilevel HVDC converters (MMC) on electromagnetic transient simulation programs[J]. IEEE Transactions on Power Delivery, 2011, 26(1): 316-324. [5] 高晨祥, 丁江萍, 许建中, 等. 输入串联输出并联型双有源桥变换器等效建模方法[J]. 中国电机工程学报, 2020, 40(15): 4955-4965. Gao Chenxiang, Ding Jiangping, Xu Jianzhong, et al.Equivalent modeling method of input series output parallel type dual active bridge converter[J]. Proceedings of the CSEE, 2020, 40(15): 4955-4965. [6] 郭琦, 卢远宏. 新型电力系统的建模仿真关键技术及展望[J]. 电力系统自动化, 2022, 46(10): 18-32. Guo Qi, Lu Yuanhong.Key technologies and prospects of modeling and simulation of new power system[J]. Automation of Electric Power Systems, 2022, 46(10): 18-32. [7] 何绍民, 张喆, 卢倚平, 等. 基于计算前沿面的实时仿真数值积分并行构造及其数值模型解耦加速方法[J]. 电工技术学报, 2023, 38(16): 4246-4262. He Shaomin, Zhang Zhe, Lu Yiping, et al.Numerical model decoupling acceleration method with numerical integration parallelism construction based on computation front in real-time simuation[J]. Transactions of China Electrotechnical Society, 2023, 38(16): 4246-4262. [8] 邵冰冰, 赵峥, 肖琪, 等. 多直驱风机经柔直并网系统相近次同步振荡模式参与因子的弱鲁棒性分析[J]. 电工技术学报, 2023, 38(3): 754-769. Shao Bingbing, Zhao Zheng, Xiao Qi, et al.Weak robustness analysis of close subsynchronous oscillation modes' participation factors in multiple direct-drive wind turbines with the VSC-HVDC system[J]. Transactions of China Electrotechnical Society, 2023, 38(3): 754-769. [9] U. Karaagac, Mahseredjian J, Gagnon R, et al. A generic EMT-Type model for wind parks with permanent magnet synchronous generator full size converter wind turbines[J]. IEEE Power and Energy Technology Systems Journal, 2019, 6(3): 131-141. [10] Ugalde-Loo C E, Ekanayake J B, Jenkins N. State-space modeling of wind turbine generators for power system studies[J]. IEEE Transactions on Industry Applications, 2013, 49(1): 223-232. [11] Trudnowski D J, Gentile A, Khan J M, et al.Fixed-speed wind-generator and wind-park modeling for transient stability studies[J]. IEEE Transactions on Power Systems, 2004, 19(4): 1911-1917. [12] Ali M, Ilie I S, Milanovic J V, et al.Wind farm model aggregation using probabilistic clustering[J]. IEEE Transactions on Power Systems, 2013, 28(1): 309-316. [13] 刘其辉, 逄思敏, 吴林林, 等. 大规模风电汇集系统电压不平衡机理、因素及影响规律[J]. 电工技术学报, 2022, 37(21): 5435-5450. Liu Qihui, Pang Simin, Wu Linlin, et al.Themechanism, factors and influence rules of voltageimbalance in wind power integration areas[J]. Transactions of China Electrotechnical Society, 2022, 37(21): 5435-5450. [14] 李龙源, 付瑞清, 吕晓琴, 等. 接入弱电网的同型机直驱风电场单机等值建模[J]. 电工技术学报, 2023, 38(3): 712-725. Li Longyuan, Fu Ruiqing, Lü Xiaoqin, et al.Singlemachine equivalent modeling of weak grid connectedwind farm with same type PMSGs[J]. Transactions of China Electrotechnical Society, 2023, 38(3): 712-725. [15] Sanchez-Gasca J J. Generic wind turbine generator models for WECC-a second status report[C]//IEEE Power & Energy Society General Meeting, Denver, CO, USA 2015: 1-5. [16] 毕天姝, 王清, 薛安成,等.基于状态矩阵和摄动理论的双馈风力发电机与同步机小扰动互作用机理[J].电工技术学报,2016,31(7):126-135. BiTianshu, Wang Qing, Xue Ancheng,et al. The mechanism of small signal dynamic interaction Between DFIG and synchronous generator based on state matrix and perturbation theories[J]. Transactions ofChina Electrotechnical Society, 2016, 31(7): 126-135. [17] 尹明, 李庚银, 张建成, 等. 直驱式永磁同步风力发电机组建模及其控制策略[J]. 电网技术, 2007(15): 61-65. Yin Ming, Li Gengyin, Zhang Jiancheng, et al.Modeling and control strategies of directly driven wind turbine with permanent magnet syn-chronous generator[J]. Power System Technology, 2007 , 31(15) : 61-65. [18] 马威. 基于永磁同步发电机的直驱式风电系统建模与仿真[D]. 兰州:兰州理工大学, 2010. Ma Wei.Modeling and simulation for direct-drive permanent magnet wind power system[D]. Lanzhou: Lanzhou University of Technology, 2010. [19] 王林富, 许丹枫, 赵湖珊, 等. 直驱永磁风力发电系统建模与仿真方法研究[J]. 电子测量技术, 2019, 42(20): 44-50. Wang Linfu, Xu Danfeng, Zhao Hushan, et al.Modeling and simulation of direct-drive permanent magnet wind power generation system based on PSCAD/EMTDC[J]. Electronic Measure ment Technology, 2019, 42(20): 44-50. [20] 严干贵, 魏治成, 穆钢, 等. 直驱永磁同步风电机组的动态建模与运行控制[J]. 电力系统及其自动化学报, 2009, 21(6): 34-39. Yan Gangui, Wei Zhicheng, Mu Gang,et al.Dynamic modeling and control of directly-driven permanent magnet synchronous generator wind turbine[J]. Proceedings of the CSU-EPSA, 2009, 21(6): 34-39. [21] Huang Y, Chapariha M, Therrien F, et al.A constant-parameter voltage-behind-reactance synchronous machine model based on shifted-frequency analysis[J]. IEEE Transactions on Energy Conversion, 2015, 30(2): 761-771. [22] Zhang P, Marti J R, Dommel H W.Synchronous machine modeling based on shifted frequency analysis[J]. IEEE Transactions on Power Systems, 2007, 22(3): 1139-1147. [23] 高仕林, 宋炎侃, 陈颖, 等. 电力系统移频电磁暂态仿真原理及应用综述[J]. 电力系统自动化, 2021, 45(14): 173-183. Gao Shilin, SongYankan, Chen Ying, et al. Overview on principle and application of shifted frequency based electromagnetic transient simulation for power system[J]. Automation of Electric Power Systems, 2021, 45(14): 173-183. [24] 申健, 金钧. 电力系统仿真分析中几种同步发电机数学模型的比选[J]. 电气技术, 2007,8(9): 48-51. Shen Jian, Jin Jun.Compare several mathematical models of synchronous machine in power system simulation analysis[J]. Electrical Engineering, 2007(9): 53-56. [25] 倪以信, 陈寿孙, 张宝霖. 动态电力系统的理论和分析[M]. 北京: 清华大学出版社, 2002. [26] 王爽, 高朝晖, 陈思宇, 等. 基于Simulink的同步发电机仿真代数环问题研究[J]. 系统仿真学报, 2022, 34(3): 482-489. Wang Shuang, Gao Zhaohui, Chen Siyu, et al.Research on algebraic loop of synchronous generator simulation based on simulink[J]. Journal of System Simulation, 2022, 34(3): 482-489. [27] 马晓虹. Matlab中的代数环问题及其消除方法[J]. 科技广场, 2010(7): 159-161. Ma Xiaohong.Algebraic rings in Matlab and their elimination methods[J]. Science and Technology Square, 2010(7): 159-161.