新型碟式太阳能跟踪平台设计和姿态工作空间分析

传统的碟式太阳能热发电系统采用回转支承和螺旋升降机来实现太阳方位角和高度角的跟踪，不足之处在于无法自动调整聚光器镜面单元的位姿以应对外界扰动。采用并联机构来实现太阳跟踪，不仅具有刚度高、跟踪误差小等内在优势，还可以自动调整聚光器镜面单元位姿。若采用传统球铰，由于其物理限制，跟踪机构的偏转能力不能精确满足太阳跟踪角度范围大的技术要求。针对上述问题，采用新型被动球铰，设计了一种基于3-RPS并联机构的新型碟式太阳能跟踪平台，并计算了其跟踪角度的范围；同时，通过建立通用3-RPS并联机构的逆运动学方程，结合球坐标搜索法计算了3-RPS并联跟踪机构的姿态工作空间，并结合结构参数对其姿态工作空间的影响规律，确定了各结构参数的最优值。结果表明：当新型碟式太阳能跟踪平台选用新型被动球铰，动、定平台形状为等腰三角形，转动副轴线共面且呈三角形布置，动、定平台的半径比为2以及支链长度为动平台半径的2倍时，其结构符合设计要求且调整后的姿态工作空间满足太阳跟踪所需的角度范围。研究结果可为后续的太阳跟踪平台结构设计和参数优化提供参考。

Design and orientation workspace analysis of new dish-type solar tracking platform

The traditional dish-type solar thermal power generation system adopts slewing ring and spiral elevator to track the azimuth angle and altitude angle of solar, but it is unable to automatically adjust the posture of the condenser mirror element to cope with external disturbances. Using the parallel mechanism to realize solar tracking not only has the inherent advantages of high stiffness and small tracking error, but also can automatically adjust the posture of condenser mirror element. If the traditional spherical hinge is used, due to its physical limitations, the deflection ability of the tracking mechanism can not accurately meet the technical requirements of a wide range of solar tracking angles. Aiming at the above problems, a new dish-type solar tracking platform based on 3-RPS parallel mechanism was designed by using a new passive spherical hinge, and its tracking angle range was calculated; at the same time, the orientation workspace of the 3-RPS parallel tracking mechanism was calculated by establishing the inverse kinematics equation of the general 3-RPS parallel mechanism and combining with the spherical coordinate search method. According to the influence law of its structural parameters on the orientation workspace, the optimal values of structural parameters were determined. The results showed that: when the new passive spherical hinge was selected, the shape of moving and fixed platforms was isosceles triangle, the rotation pair axes were coplanar and triangular, the radius ratio of the moving and fixed platforms was two, and the branch chain length was twice the moving platform radius, the structure of new dish-type solar tracking platform met the design requirements, and the adjusted orientation workspace met the angle range required for solar tracking. The research results can provide reference for the subsequent structure design and parameter optimization of solar tracking platforms.