Abstract

Doubly fed induction generator (DFIG) is one of the important generators that is used in the wind turbines structure. In the previous years, DFIGs based wind turbine system that have installed in the onshore and offshore wind farms have more number than other generators. In this paper, a new method has been presented for design and optimization of a 500 kW DFIG. At first, equations of the optimal design are reviewed for this generator, and then a model is presented for the study of the generator operation. The detailed design of DFIG is done and finite element analysis (FEA) is used to verify the design. In the following, a link is created by a software between FEA tool and genetic algorithm (GA) that is used for optimization. In each iteration, input parameters are changed by GA and is sent to FEA tool for calculation of cost functions. In other words, GA presents a new rotor, and stator slot dimension in each iteration and effect of these parameters is checked on generator operation by FEA tool, e.g., Ansys Maxwell Software. Input parameters that are created the best cost functions are selected as optimized parameters. Rotor and stator slots dimension have been selected as input parameters and cost functions are efficiency, rotor copper loss, and electromagnetic torque. In the results section, a comparison is done between analytical design and FEA design and then output wave of designed DFIG is proposed. In the following, sensitivity analysis is presented that is a study about effect of changing slot dimension on DFIG parameters. Finally optimization results are proposed for each cost function. Results show effectiveness of the proposed method, i.e., we can improve output parameters of DFIG via changing slot dimension.

摘要

双馈感应发电机（DFIG）是风力涡轮机结构中使用的重要发电机之一。在过去的几年中，已在陆上和海上风电场安装的基于DFIG的风力涡轮机系统的数量比其他发电机要多。在本文中，提出了一种用于设计和优化500 kW DFIG的新方法。首先，回顾了该发电机的最佳设计方程，然后给出了一个用于发电机运行研究的模型。完成了DFIG的详细设计，并使用了有限元分析（FEA）来验证设计。在下面，由软件在FEA工具和用于优化的遗传算法（GA）之间创建链接。在每次迭代中，输入参数均由GA更改，然后发送到FEA工具以计算成本函数。例如Ansys Maxwell Software。选择最佳成本函数创建的输入参数作为优化参数。已选择转子和定子槽的尺寸作为输入参数，成本函数是效率，转子铜损和电磁转矩。在结果部分中，对分析设计和FEA设计进行了比较，然后提出了设计的DFIG的输出波形。在下文中，提出了灵敏度分析，该灵敏度分析是关于更改插槽尺寸对DFIG参数的影响的研究。最后，针对每个成本函数提出了优化结果。结果表明了该方法的有效性，即可以通过改变插槽尺寸来改善DFIG的输出参数。