Charging and Discharging Control Strategy of Dump Truck Braking Energy Recovery System Based on Self-adaption Two-Degree-of-Freedom PID

When working in harsh conditions, the dump truck brakes frequently. And the braking energy consumption of it accounts for a large proportion of the total energy consumption. Due to the wide range fluctuation and high frequency of the instantaneous wide range fluctuation on DC bus voltage, the efficient and stable control on braking energy recovery and utilization system is a key challenge that needs to be solved urgently. This paper proposes a self-adaption two-degree-of-freedom PID control strategy, which implements high efficient and stable control of the charging and discharging process of the system. Meanwhile, the response speed of charging and discharging current are accelerated and the interference resistant capacity is also improved in the charging and discharging process. The experimental platform of braking energy recovery and utilization system of the dump truck with 300kW/1800V supercapacitor and battery mixed energy storage was built. And the establishment of prototype had been completed. Finally, vehicle operation Experiment was conducted on the 730E tramcar in Ping Shuo An-Jialing coal mine. The experimental results were tested by a third party, and the efficiency of the braking energy recovery and utilization system reached 53.5%. The experimental result verified the efficiency, feasibility and stability of the charging and discharging control strategy.