直驱式高转矩密度双磁场调制永磁风力发电机关键技术研究

As modern wind turbines propose higher requirements on the volume, weight, reliability, maintainability and cost per unit electrical power generation, it is necessary to improve the topology and design of the wind power generator. In this project, a novel direct-drive dual flux modulation permanent magnet wind power generator with high torque density is proposed basing on the magnetic modulation effect. The proposed coaxial permanent magnet wind power generator with double-stator and double-rotor could realize a dual flux modulation effect and further help to improve the utilization of the permanent magnet as well as the torque density. It is very difficult to accurately build the analytical model and evaluate the characteristics of the wind power generator, because of the electromagnet, thermo and stress multi-physics coupling and high nonlinear property. Moreover, the dynamic characteristics such as output power, power factor, efficiency, torque, temperature rise, vibration and noise of the wind power generator could be greatly influenced by the change of the operating conditions. In view of the above reasons, the precise multi-physics coupling calculation model and design method, which is corrected by experimental result obtained on a down-scale prototype, will be established to reveal the influence law of the main design parameters, operating conditions and control strategy on the static and dynamic characteristics of the wind power generator. Furthermore, a comprehensive quantitative evaluation method will be proposed to realize the multi-objective optimization of the proposed novel wind power generator based on Pareto fronts. This project may lay the theoretical foundation and provide technical support for the technical breakthrough in realizing modern direct-drive wind power generator.

现代风机对大容量风力发电机体积、重量、可靠性、维护性、单位发电成本有更高要求，亟需对风力发电机拓扑结构和设计技术进行革新。本项目利用磁齿轮的磁场调制效应，提出一种新型高转矩密度直驱式双磁场调制永磁风力发电机。这种具有双定子、双转子同轴式结构的永磁发电机可实现双重磁场调制作用，提高永磁体利用率和转矩密度。针对兆瓦级以上大容量风力发电机设计中存在电磁场、温度场、应力场等多物理场耦合，模型高度非线性，难以精确计算的问题，以及风机运行工况时变性引发发电机输出电能参数、转矩、温升、振动、噪音变化等动态特性问题，本项目将建立该发电机经实验修正的多场耦合精准计算模型，揭示发电机主要设计参数、外部运行工况以及不同控制策略对发电机静、动态特性的影响规律，提出发电机综合量化评价方法，实现对该发电机的Pareto多目标综合优化设计。该项目将为实现现代大容量直驱式风力发电机技术突破提供理论基础和技术支撑。

为研究开发大型直驱永磁风力发电机拓扑及设计技术，本项目将直驱永磁发电机与磁场调制技术相结合，提出一种新型高转矩密度直驱式双磁场调制永磁风力发电机拓扑及其优化、控制方法。该电机包含两个调制环和两个定子，绕组嵌在辅助调制环的槽中。主要研究内容包括：1、高转矩密度磁齿轮及磁场调制永磁风力发电机拓扑设计。通过分析磁场调制电机转矩提升机理，提出新的高转矩密度磁齿轮及磁场调制电机拓扑2、发电机多物理场耦合建模分析。通过对发电机多物理场耦合建模，分析额定工况下发电机关键部件所受电磁力及应力分布，分析发电机振动噪声特性，证明了该拓扑具有较高的可靠性3、发电机性能综合量化评估及多目标鲁棒优化方法。基于多项式回归模型建立发电机高精度代理模型，提出了一种基于多目标粒子群优化方法和多重蒙特卡罗模拟的多目标鲁棒性优化及分析方法，对发电机进行多目标鲁棒优化并对优化结果的鲁棒性进行评估4、高动态运行控制策略。截至目前的研究结果表明，所提双磁场调制永磁风力发电机拓扑可有效提升转矩密度，但受到加工工艺的影响，其铁损值未能达到预期水平，需要进一步研究改进。所提多目标鲁棒性优化方法能够有效地减小由制造公差等因素产生的不确定性参数引起的性能波动。本项目涉及的高转矩密度双磁场调制永磁风力发电机及其优化、控制方法具有创新性，具有广阔的应用前景和潜在的经济、社会效益。