Journal of Central South University | 2019
Soft measurement model on torque of alternating current electrical dynamometer including copper loss and iron loss
Abstract
Alternating current electrical dynamometer is a common device to measure the torque of engines, such as the gasoline engine. In order to solve the problems such as high cost, high energy consumption and complicated measurement system which exists in the direct measurement on the torque of alternating current electrical dynamometer, copper loss and iron loss are taken as two key factors and a soft-sensing model on the torque of alternating current electrical dynamometer is established using the fuzzy least square support vector machine (FLS-SVM). Then, the FLS-SVM parameters such as penalty factor and kernel parameter are optimized by adaptive genetic algorithm, torque soft-sensing is investigated in the alternating current electrical dynamometer, as well as the energy feedback efficiency and energy consumption during the measurement phase of a gasoline engine loading continual test is obtained. The results show that the minimum soft-sensing error of torque is about 0.0018, and it fluctuates within a range from −0.3 to 0.3 N-m. FLS-SVM soft-sensing method can increase by 1.6% power generation feedback compared with direct measurement, and it can save 500 kJ fuel consumption in the gasoline engine loading continual test. Therefore, the estimation accuracy of the soft measurement model on the torque of alternating current electrical dynamometer including copper loss and iron loss is high and this indirect measurement method can be feasible to reduce production cost of the alternating current electrical dynamometer and energy consumption during the torque measurement phase of a gasoline engine, replacing the direct method of torque measurement.摘要交流电力测功机是测量发动机转矩的常用仪器设备。针对交流电力测功机扭矩直接测量中存在 的问题, 如成本高、能耗高、测量系统复杂等, 以铜损和铁损为两个主要因素, 利用模糊最小二乘支 持向量机(FLS-SVM)建立了交流电力测功机的扭矩软测量模型。然后, 采用自适应遗传算法对 FLS-SVM 的惩罚因子和核参数进行优化, 将扭矩软测量模型应用于交流电力测功机中, 并与其他软 测量模型和直接测量进行比较和分析, 得到了汽油机连续负载试验测量阶段的能量反馈效率和能耗。 结果表明, FLS-SVM 软测量扭矩的最小软测量误差约为0.0018, 在−0.3~0.3 N·m 范围内波动, 比直 接测量法提高了1.6%的能量反馈效率, 并在汽油机连续负载试验中节省了500 kJ 的油耗。因此, 含 铜损、铁损的交流电力测功机扭矩软测量模型的测量精度较高, 这种间接测量方法可替代直接扭矩测 量方法, 并降低交流电力测功机的生产成本和能耗。