Abstract：Wind energy and wave energy have high energy density and strong predictability, and have gradually become a research hotspot of new energy power generation. However, when wind and wave energy are generated independently, building separate pile foundation platforms is costly and has low power density. The offshore wind-and-wave combined energy conversion (WWCEC) system improves power density and reduces development costs by comprehensively utilizing wind and wave energy. The traditional WWCEC system generates power using multiple independent generators or couples energy via mechanical devices. The former system has a large volume, a high sea-area occupancy rate, and high construction costs. The latter has a complex transmission structure, resulting in significant efficiency losses and maintenance issues. This paper proposes a new direct-drive WWCEC system based on a two-degree-of-freedom linear rotary generator (LRG) that enables direct-drive integrated power generation from both wind and wave energy. Firstly, this paper develops an LRG mathematical model as the core energy-conversion device for the two- degree-of-freedom direct-drive wind-wave combined power generation system, serving as the basis for the entire system. A prototype was fabricated, and an experimental platform was built for testing. The test results are compared with the finite element analysis and the mathematical model outputs. The experimental results are in good agreement with the simulation results, which demonstrates the accuracy and reliability of the LRG modeling. At the same time, it partially verifies the effectiveness of the proposed wind-wave combined power generation system for the integrated development of wind and wave energy. Secondly, this paper designs a complete set of microgrid topologies for the new direct-drive WWCEC system and develops mathematical models for each component. Then, by combining the control strategies for each part, a simulation model is built to verify the system's operational stability under switching conditions and load variations. The simulation results show that the sinusoidal waveforms of voltage and current at the system output are good, and that the total harmonic distortion and current frequency fluctuation meet the grid-connected standard, indicating excellent dynamic stability. In summary, this paper innovatively employs a two-degree-of-freedom generator to integrate offshore wind and wave energy into a unified power-generation architecture. The proposed system achieves a 49.75% higher annual power density and a 7.05% lower levelized electricity cost than the traditional offshore wind-wave power generation system. Its design concept offers a new engineering implementation path for large-scale offshore wind and wave energy development, particularly for island power supply and marine ranching applications.
聂瑞, 张豪, 魏彦企, 李忠文, 司纪凯. 两自由度直驱风浪结合发电系统建模[J]. 电工技术学报, 2026, 41(18): 6123-6137.
Nie Rui, Zhang Hao, Wei Yanqi, Li Zhongwen, Si Jikai. Modeling of Two Degrees of Freedom Direct-Drive Wind-Wave Combined Power Generation System. Transactions of China Electrotechnical Society, 2026, 41(18): 6123-6137.
[1] 国家能源局. 国家能源局关于促进新能源集成融合发展的指导意见[EB/OL]. 国能发新能[2025]93号, 2025- 10-31[2025-12-12]. https://www.nea.gov.cn/20251112/79210278a3184efea9ccf2d546fdf1b7/c.html. [2] 中华人民共和国国家发展和改革委员会. 发展海洋经济推进建设海洋强国的理论脉络与实践路径[EB/OL]. 习近平经济思想研究中心, 2024-03-07[2025-12-12]. https://www.ndrc.gov.cn/wsdwhfz/202403/t20240307_1364687.html. [3] 申刘飞, 翟雨佳, 吴星徵, 等. 海上超导风电制氢一体化研究进展与发展趋势[J]. 电工技术学报, 2025, 40(11): 3362-3380. Shen Liufei, Zhai Yujia, Wu Xingzheng, et al.Progress and development trend of integrated research on hydrogen production from offshore supercon- ducting wind power[J]. Transactions of China Elec- trotechnical Society, 2025, 40(11): 3362-3380. [4] Tian Xinshou, Chi Yongning, Li Longxue, et al.Review of the configuration and transient stability of large-scale renewable energy generation through hybrid DC transmission[J]. CES Transactions on Electrical Machines and Systems, 2024, 8(2): 115-126. [5] Du Junfeng, Zhang Deqing, Zhang Yanfeng, et al.Design and comparative analysis of alternative mooring systems for offshore floating photovoltaics arrays in ultra-shallow water with significant tidal range[J]. Ocean Engineering, 2024, 302: 117649. [6] Kitaba T.Modeling the system for hybrid renewable energy using highly efficient converters and gen- erator[J]. CES Transactions on Electrical Machines and Systems, 2024, 8(3): 356-366. [7] 贺玮杰, 冯忠楠, 林湘宁, 等. 考虑源网储协同配合下的移动式波浪能发电平台并网优化调度[J]. 电工技术学报, 2024, 39(20): 6502-6516. He Weijie, Feng Zhongnan, Lin Xiangning, et al.Grid-connected optimization dispatch of mobile wave energy power generation platform considering the coordination of source, network and storage[J]. Transactions of China Electrotechnical Society, 2024, 39(20): 6502-6516. [8] Dang T D, Phan C B, Truong H V A, et al. A study on modeling of a hybrid wind wave energy converter system[C]//2016 16th International Conference on Control, Automation and Systems (ICCAS), Gyeongju, Korea, 2016: 182-187. [9] Rahman M A, Islam M R, Muttaqi K M, et al.Modeling and design of a multiport magnetic bus- based novel wind-wave hybrid ocean energy tech- nology[J]. IEEE Transactions on Industry Appli- cations, 2021, 57(5): 5400-5410. [10] Fu Xinghe, Wang Jianhao, Lin Mingyao.Design and analysis of linear rotary permanent magnet generator for wind-wave combined power generation system[C]//2017 20th International Conference on Electrical Machines and Systems (ICEMS), Sydney, Australia, 2017: 1-6. [11] Xu Lei, Zhang Chao, Zhu Xiaoyong.Decoupling control of a dual-stator linear and rotary permanent magnet generator for offshore joint wind and wave energy conversion system[J]. IET Electric Power Applications, 2020, 14(4): 561-569. [12] Nie Rui, Si Jikai, Wang Peixin, et al.Corrections to “optimization design of a novel permanent magnet linear-rotary generator for offshore wind-wave com- bined energy conversion based on multi-attribute decision making”[J]. IEEE Transactions on Energy Conversion, 2025, 40(3): 2446. [13] Nie Rui, Si Jikai, Jia Yifei, et al.Comprehensive comparison of mover-PM and stator-PM linear-rotary generators for wind-wave combined energy con- version system[J]. IEEE Transactions on Industry Applications, 2024, 60(4): 6170-6185. [14] Szabó L.On the use of rotary-linear generators in floating hybrid wind and wave energy conversion systems[C]//2018 IEEE International Conference on Automation, Quality and Testing, Robotics (AQTR), Cluj-Napoca, Romania, 2018: 1-6. [15] Khodabakhsh J, Mohammadi E, Moschopoulos G.PMSG-based wind energy conversion systems integration into DC microgrids with a novel compact converter[J]. IEEE Access, 2020, 8: 83583-83595. [16] 林莉, 林雨露, 谭惠丹, 等. 计及SOC自恢复的混合储能平抑风电功率波动控制[J]. 电工技术学报, 2024, 39(3): 658-671. Lin Li, Lin Yulu, Tan Huidan, et al.Hybrid energy storage control with SOC self-recovery to smooth out wind power fluctuations[J]. Transactions of China Electrotechnical Society, 2024, 39(3): 658-671. [17] Rasool S, Muttaqi K M, Sutanto D.A multi-filter based dynamic power sharing control for a hybrid energy storage system integrated to a wave energy converter for output power smoothing[J]. IEEE Transactions on Sustainable Energy, 2022, 13(3): 1693-1706. [18] 赵悦, 陈卓易, 沈非凡, 等. 基于单电阻采样的永磁同步电机有限集模型预测控制[J]. 电工技术学报, 2026, 41(2): 487-498. Zhao Yue, Chen Zhuoyi, Shen Feifan, et al.Finite- control-set model predictive control of permanent magnet synchronous motor based on single resistor sampling[J]. Transactions of China Electrotechnical Society, 2026, 41(2): 487-498. [19] 宋琳, 聂子玲, 孙军, 等. 基于参数辨识的永磁同步直线电机循环神经网络多维观测器[J]. 电工技术学报, 2024, 39(22): 7059-7072. Song Lin, Nie Ziling, Sun Jun, et al.Multidi- mensional observer of permanent magnet synchronous linear motor recurrent neural network based on parameter identification[J]. Transactions of China Electrotechnical Society, 2024, 39(22): 7059-7072. [20] 张超, 文云峰, 黎婧娴, 等. 考虑抑制二次跌落的风电自适应频率支撑控制策略及其参数整定[J]. 电工技术学报, 2026, 41(5): 1510-1525. Zhang Chao, Wen Yunfeng, Li Jingxian, et al.An adaptive frequency support control strategy and parameter configuration method of wind power considering the mitigation secondary drop[J]. Transactions of China Electrotechnical Society, 2026, 41(5): 1510-1525. [21] 范晨兴, 杨建飞, 邱鑫, 等. 基于CFD的垂直轴风机特性的叶片优化与系统能源设计[J]. 电机与控制应用, 2025, 52(10): 1125-1136. Fan Chenxing, Yang Jianfei, Qiu Xin, et al.CFD- based blade optimisation and system energy design for vertical axis wind turbine characteristics[J]. Electric Machines & Control Application, 2025, 52(10): 1125-1136. [22] 段连龙, 刘占芳, 谭术平, 等. 海上浮式10 MW级垂直轴风机气动特性[J]. 船舶工程, 2023, 45(增刊1): 75-81. Duan Lianlong, Liu Zhanfang, Tan Shuping, et al.Aerodynamic characteristics of offshore floating 10 MW vertical axis wind turbine[J]. Ship Engineering, 2023, 45(S1): 75-81. [23] 方红伟, 宋如楠, 姜茹, 等. 振荡浮子式波浪能转换装置的全电气化模拟研究[J]. 电工技术学报, 2019, 34(14): 3059-3065. Fang Hongwei, Song Runan, Jiang Ru, et al.An oscillating buoy type wave energy converter with all-electrical analogue method[J]. Transactions of China Electrotechnical Society, 2019, 34(14): 3059-3065. [24] 张凯铭. 风光互补发电系统最大功率点跟踪及储能控制策略研究[D]. 哈尔滨: 东北农业大学, 2023. Zhang Kaiming.Research on MPPT and energy storage control strategy of wind-solar hybrid power generation system[D]. Harbin: Northeast Agricultural University, 2023. [25] 罗宇航, 肖凡, 郑宇婷, 等. 基于稳定域的PQ控制并网逆变器稳定性分析方法[J]. 电工技术学报, 2025, 40(22): 7334-7348. Luo Yuhang, Xiao Fan, Zheng Yuting, et al.Stability analysis method of grid-connected inverter with PQ control based on stable operating region[J]. Trans- actions of China Electrotechnical Society, 2025, 40(22): 7334-7348. [26] 陈杰, 陈新, 冯志阳, 等. 微网系统并网/孤岛运行模式无缝切换控制策略[J]. 中国电机工程学报, 2014, 34(19): 3089-3097. Chen Jie, Chen Xin, Feng Zhiyang, et al.A control strategy of seamless transfer between grid-connected and islanding operation for microgrid[J]. Proceedings of the CSEE, 2014, 34(19): 3089-3097. [27] 拓又达科技集团. 1kW垂直轴风力发电机组[EB/OL].[2025-09-26]. http://www.toyoda-net.com/product.html. [28] 杭州巨浪能源科技有限公司. 波浪能供电浮标, 海上供能新方式[EB/OL]. 北京:北极星电力新闻网, 2021-12-16[2025-01-15]. https://news.bjx.com.cn/html/20211216/1194160.shtml.
2026, Vol. 41 
