The Research On Braking Energy Feedback Control Strategy Of Serial Hybrid Vehicle

With the development of technology,the brake energy feedback technology in the transportation field has received more and more attention.The recovery of vehicle braking energy not only reduces environmental pollution,saves energy,but also reduces vehicle operating costs.As a transportation tool in the mining industry,mine transportation vehicles generally use oil-electric series hybrid power as the driving force.Due to the large mass and load capacity of mining truck,there is a large inertia kinetic energy during operation,downhill and deceleration.It consumes a lot of energy when braking.In the traditional mining truck braking,friction braking or resistance braking is generally adopted.Both of these methods dissipate the braking energy in the form of heat,which causes great waste of energy.In order to improve the efficiency of energy utilization,we focus on the braking energy recovery problem for the series hybrid electric wheel mining truck.This paper we first analyzes the energy flow of mining truck during regenerative braking,and then analyzes the energy loss when mining truck brakes.It will generate a large brake feedback energy for mining truck braking,this paper uses a combination of supercapacitor and battery pack to absorb the energy generated by mining truck brakes.The motor control of mining truck adopts the traditional vector control mode,and simulates the start,driving at a constant speed and braking of mining truck through simulation.By analyzing and comparing the structure of the energy storage device,it is determined that the battery pack and the super capacitor group are respectively used for power conversion.The structure in which the device is connected and then connected in parallel to the DC bus.The principle of mining truck brake energy feedback is introduced.The basic dynamic model of mining truck is analyzed and the energy of the brake is calculated.Based on the analysis of super capacitor and battery equivalent circuit model and SOC estimation method,the design is based on Regular braking energy recovery control strategy.The traditional control method of braking energy recovery is to control the absorbed energy by the double closed loop form of the inner loop of the voltage outer loop current.In this way,the DC bus voltage has strong stability,but it cannot effectively distribute the energy of feed back.So in order to improve the shortcomings,the power of the feedback absorption is determined as the control target,and the double closed-loop control mode of the inner loop of the power outer loop current is used to optimally distribute the energy absorbed by the super capacitor and the battery pack.The most efficient recycling utilizes the energy of the brake feedback,making the energy storage device more optimised.Finally,the main circuit of the braking energy recovery control system and the control system hardware circuit are designed.The supercapacitor and battery parameters are matched according to the parameters of the vehicle and the braking energy.The software design is carried out according to the proposed control strategy.The control strategy was tested to verify the validity and practicability of the design.