大兆瓦级风电制动器制动机理及多目标结构优化

Aim to the problems existing in brake of high-megawatt class wind-driven generator, such as low braking reliability and short longevity of brake ling, the friction and wearing principle of brake ling, the dynamic characteristics and reliability evaluation method of braking and compensating components, the topology optimization design of brake structure are studied deeply. The detailed research contents include: (1) By building flash thermal model and nominal surface thermal model of the pair of friction components, and analyzing the transformation and distribution of temperature gradient and thermal distortion, the friction and wearing principle and thermal declination of brake ling by thermal-mechanical coupling action are studied; (2) The dynamic characteristics of braking and compensating components in high-speed and heavy-load braking operating mode are analyzed, the acting mechanism of braking and compensating components to braking efficiency in the stage of instantaneous contact, sliding and scraping and librating are revealed, the reliability evaluation method of braking and compensating components is presented; (3) The multiobjective topology optimization of brake structure by coupling action of temperature field and elastic field is realized, the new-style brake of high-megawatt class wind-driven generator which can applied in high-speed and heavy-load operating mode is designed. The research findings have important scientific and practiical significance in richening design theory of brake in wind-driven generator, improving the design and manufacturing level of brake of high-megawatt class wind-driven generator, changing the excessive import relying actuality of brake in high-megawatt class wind-driven generator, and enhancing the rapid development of green energy source of our country.

针对目前国产大兆瓦级风电制动器制动可靠性差、制动闸片使用寿命短等问题，深入进行制动闸片的摩擦磨损规律、制动与补偿机构动力学特性和可靠性评估方法以及制动器结构拓扑优化设计研究。内容主要包括：建立制动摩擦副局部闪温和名义表面温升模型，分析其温度梯度与热变形的变化及分布规律，研究热-力耦合作用下制动闸片的摩擦磨损规律及热衰退性；分析在高速重载制动工况下风电制动器制动与补偿机构的动态特性，揭示其在接触瞬时、划擦及制动振颤阶段对制动效能的影响机理，提出制动与补偿机构可靠性评估方法；实现温度场与弹性场耦合作用下的高效能低损耗制动器多目标结构拓扑优化，研制出适用于高速重载工况的大兆瓦级新型风电制动器。研究成果对于丰富我国风电制动器的设计理论、提高大兆瓦级风电制动器的设计和制造水平、有效改变大兆瓦级风电制动器过度依赖进口的局面、推动绿色能源事业的快速发展等方面具有重要理论意义和应用价值。

针对目前国产大兆瓦级风电制动器制动可靠性差、制动闸片使用寿命短等问题，深入进行制动闸片的摩擦磨损规律、制动与补偿机构动力学特性和可靠性评估方法以及制动器结构拓扑优化设计研究。在以下4个方面取得了进展：.（1）研究高速重载工况下制动闸片微观摩擦机理，基于W-M分形理论，建立了制动过程中微凸体间挤压、搓动的热-力耦合微观模型，获得了制动摩擦副局部闪温与热变形变化及分布规律；提出了位移梯度循环法，建立制动器摩擦副三维瞬态传热有限元模型，运用速度梯度循环法推导出热流密度的加载式，得到了温度和应力应变分布规律，分析了热-力耦合作用下制动闸片的摩擦磨损及热影响规律。.（2）对制动过程中大兆瓦级风电制动器制动与补偿机构进行柔性多体系统动力学建模，研究在高速重载制动工况下制动器制动与补偿机构的动态特性；结合制动过程温度场的分析，得到了热-力耦合作用下的制动器动态特性；推导了制动器制动过程中制动盘振动稳定性的Sperling评估模型，分析了制动器制动与补偿机构在冲击载荷下接触界面间相互作用，提出了风电制动器制动与补偿机构可靠性评估方法。.（3）建立了制动闸片多物理场工况有限元分析模型，提出了适合于大兆瓦风电制动器多场耦合工况的拓扑优化设计方法，分别得到了在静态、动静态、热结构耦合条件下大兆瓦风电制动器制动闸片优化结构；建立了大兆瓦风电制动器制动盘结构拓扑优化模型，提出了适应制动盘移动载荷特性的等效移动载荷结构拓扑优化设计方法，获得了优化后大兆瓦风电制动器制动盘结构；优化了制动钳体，得到了高效能低损耗制动器的优化结构。.（4）建立了高效能低损耗风电制动器虚拟样机系统，验证了优化后风电制动盘结构的合理性；基于缩比理论设计缩比试验台及试验数据采集系统，进行制动试验，得到了高速重载制动过程的系列化试验数据；研究了挤压切削加工工艺和盐浴渗氮表面处理工艺，为适用于高速重载工况的高效能低损耗大兆瓦级风电制动器的制造工艺提供技术参考。