摘要：
Using electrical inertia instead of mechanical flywheel to simulate the energy conversion of vehicle frictional braking process is the development trend of brake dynamometer. Electrical inertia control algorithm becomes the key to simulating the vehicle load with brake test stand. In view of the problems of inertia simulation deviation and the fluctuation in torque control method, an inertia deviation control algorithm is proposed for the train braking test stand. In this algorithm, the braking energy equation is introduced into the mean inertia calculation, and both the mean inertia deviation and the instantaneous inertia deviation are directly used as the inputs of the algorithm to control the motor torque output. The control strategy of motor torque correlation based on different deviation sizes is designed, which achieves the aims of improving the simulation precision and reducing the inertia fluctuation. The inertia deviation control algorithm and the torque control method are compared by brake tests. The instantaneous inertia deviation results show that, by the proposed inertia deviation control algorithm, the braking time with >5 kg.m2 deviation is shortened by 60%, and the inertia simulation error is decreased from 10% to 1%, compared with those by the torque control method. The proposed algorithm overcomes such defects that the simulation precision is easy to be affected by the angular deceleration calculation delay, the performance change of friction material, and the mechanical resistance, etc.%采用电惯量替代机械飞轮模拟车辆摩擦制动过程的能量转化,是制动试验台的发展趋势,电惯量控制算法就成为制动试验台模拟车辆载荷的关键.针对列车制动试验台,基于转矩控制计算方法存在的惯量模拟偏差及波动大的问题,提出了惯量偏差控制算法.该算法将制动能量方程引入平均惯量计算中,将平均惯量及瞬时模拟惯量值与目标值的偏差,直接作为算法输入量,控制电机转矩.通过惯量偏差控制方程,实现了基于不同偏差量的电机转矩控制策略,达到了提高模拟精度、减小惯量波动的目的.将提出的惯量偏差控制算法与转矩控制法进行了比较试验.结果显示,惯量偏差控制法模拟的瞬时惯量,偏差超过5 kg.m2以上的时间占总制动时间的比例,比转矩控制法小60%,惯量模拟误差从10%降到了1%.相对于转矩控制算法,基于惯量偏差的电惯量控制算法,克服了模拟精度易受角减速度计算时滞、摩擦材料性能变化、机械阻力等因素影响的缺陷.
