Control scheme of electric driving system for large electric wheel mine-used truck

The power demand of large electric-wheel mine-used trucks fluctuates greatly. It has high requirements for the backup power during acceleration and the energy recovery capacity during braking. The traditional hybrid vehicle adopts the parallel power supply method of a generator set and a single power battery. However, this method is difficult to meet the vehicle’s dual requirements for peak power and energy. In order to solve the above problem, a control scheme of electric driving system for large electric wheel mine-used truck is designed, and an energy cooperative control strategy based on the combination of power following and bus voltage regulation is proposed. In the energy control process, the generator set and battery set are used as the main energy source to follow the target demand power, the super capacitor is used as the auxiliary energy source, and the DC bus voltage is regulated by alternating the work of super capacitor and generator set. Hence, the truck can automatically select the suitable bus voltage regulation mode according to the driving conditions. Considering the limitation of the maximum charging capacity and the battery life, a method is proposed in which the super capacitor is responsible for the circuit energy recovery and slowly transfers energy to the battery according to the remaining power of the super capacitor. The simulation results of the extreme driving conditions of a specific truck show that the control scheme ensures that the truck has sufficient driving power and improves the efficiency of the electric driving system. The scheme reduces the number of repeated charging and discharging of the lithium battery, which is helpful to extend the lithium battery life. Moreover, the scheme ensures the stability of the DC bus voltage when the high power fluctuates, which improves the reliability of the electric driving system.