中文摘要：

通过建立1．5MW风力发电齿轮传动系统动力学微分方程，考虑由风速变化引起的外部激励和由时变啮合刚度与综合误差引起的内部激励，应用模态叠加法求解系统的动力学微分方程并给出了使用系数和动载系数的表达式。在此基础上，对齿轮传动系统的优化问题进行了深入研究，建立以等强度原则和可靠性为约束，以体积最小为目标的优化设计数学模型，利用Matlab的优化工具进行优化，并对实例进行分析计算。分析结果表明，给出的变工况动载荷条件下的风电齿轮传动系统优化设计方法和得到的设计参数，能有效地提高传动系统的可靠度，明显降低重量和体积。

英文摘要：

The differential equations which govern the behavior of the gear transmission system of a 1.5 MW wind turbine are established, the external excitation caused by wind speed changes is discussed, and the internal excitation due to time-varying mesh stiffness and comprehensive error is also analyzed. Based on the presented models, the expression of the application factor and dynamic load factor are obtained. Optimization design model with minimal volume is described, in which the equal-strength principle and reliability are considered. The results demonstrate that the method presented is an effective way to enhance system reliability and reduce the weight and the volume.