Research On Key Technology Of Parallel Bidirectional DC-DC Power Supply Based On DSP

In recent years,with the rapid development of the power battery industry,the research on the DC-DC power supply of the power battery charging and discharging module is further deepened.In this paper,for the application of power battery component power supply,DSP power technology is used to realize the topology control of Buck-boost.On the basis of the previous,the dynamic performance of the power supply,high-precision battery charge and discharge control,and multi-channel parallel control are realized.The research contents are as follows:Firstly,the Laplace transform is used to establish the mathematical model of the DC-DC circuit,and the basic control principle and characteristics of the single-channel operation are analyzed.Multi-channel parallel is a complex coupling system with multiple inputs and multiple outputs.For the parallel current sharing problem,the mathematical model of the channel parallel structure is established.The algorithm theory analysis of multiple parallel current sharing control methods for parallel current sharing problem is carried out.It mainly includes the average current sharing method,the maximum current sharing method,the master-slave mode current sharing method,and the constant current output mode independently controlled by each channel software.The system control equations are established according to the control law corresponding to different control methods.The first-order linear non-secondary equations are used to solve the parallel control stability conditions,and the convergence of the Lyapulov Liaplov stability analysis system in the field is used.Then the DSP controlled power hardware circuit platform is designed,including the main circuit and sampling control circuit.According to the internal structure of the DSP chip,the logic of the CPU+CLA algorithm is used to run the logic,and the sampling,interrupt,and CLA module functions of the chip are configured to complete the output process of the DSP single-cycle sampling operation.Under the DSP control platform,the parameter identification and feedforward control algorithm is used to solve the DC-DC power supply dynamic control problem.Based on the theoretical analysis of the channelparallel control method,the parallel control algorithm is designed.The simulation is based on the MATLAB platform,and the simulation data structure of the DSP chip sampling control operation is built.The hardware circuit simulation is realized by simulink,and the file realizes the equivalent simulation of DSP algorithm.The single-channel,multi-channel parallel DSP algorithm is simulated.The genetic algorithm is used to optimize the model control parameters of feedforward control.The hardware circuit is tested experimentally,and the oscilloscope is used to verify the step response control and parallel control effect.The channel output accuracy and output current stability index parameters are analyzed using a high resolution test instrument.The experimental results show that the parameter identification and feedforward control algorithm can improve the dynamic performance of the system and adapt to different external loads.Parallel control can solve the current sharing problem caused by the difference of parallel parameters of the system.