基于定子全浸式及绕组内冷式的蒸发冷却永磁直驱风力发电机优化设计研究

Optimization Research of Evaporative Cooling Permanent-magnet Wind Generators based on Stator Fully Immersion and Winding Internal Cooling

为了充分发挥蒸发冷却技术在风力发电领域中高效的散热性能以及免维护的自循环特性,本文基于发电机定子全浸泡以及绕组空心导线内冷的两种散热形式,对一系列不同功率等级下的直驱式永磁风力发电机进行了优化设计研究,并对不同冷却技术路线下的电机优化设计方案进行了对比和分析。本文首先分析了不同技术路线下不同蒸发冷却系统各自所具有的特点及优势;之后基于电磁场和传热学理论建立了发电机电磁参数及温度场的分析计算模型,并基于冷却系统的结构布局分析了不同技术路线下发电机定子的传热特性;最后基于发电机电磁场和温度场的耦合分析建立了风力发电机的优化设计模型,通过多目标遗传优化算法,对2MW、5MW和10MW三种不同功率等级下的直驱式永磁风力发电机进行了以材料和成本为目标的电机系统优化设计。优化结果及对比分析表明,针对兆瓦级直驱式风力发电机而言,采用空心导线内冷式技术更具有设计成本和冷却性能上的优势,本文中的优化方法和策略可以为蒸发冷却永磁直驱式风力发电机的优化设计提供理论依据和设计基础。

In order to functionate the efficient heat dissipation performance and the maintenance-free self-circulation characteristics of evaporative cooling technology in the field of wind power,a series of permanent magnet(PM)wind generators are optimized and analyzed based on two heat dissipation modes of stator fully immersion and winding direct cooling in this paper.The optimal design schemes of the wind generators under different cooling technology routes are compared and analyzed.First of all,the characteristics and advantages of different evaporative cooling systems under different technical routes are analyzed.Then based on the theory of electromagnetic field and heat transfer,an analysis and calculation model of the electromagnetic parameters and temperature field of the generator is established,and the heat transfer characteristics of the stator delivered by different technical routes are analyzed based on the structural layout of the cooling system.Finally,based on the coupling analysis of the electromagnetic field and temperature field of the generator,the optimal design model of the wind generator is established.Based on the multi-objective genetic optimization algorithm,the generator system optimization design of the PM direct-drive wind generators with 2MW,5MW and 10MW power levels is carried out with the objective of material and cost.The optimal results show that the inner cooling route is more advantageous for megawatt direct-drive wind generators.The optimization method and conclusion in this paper can provide theory and basis for the design and optimization of evaporative cooling PM wind generator.