Research On A 42 V Battery-Ultra-capacitor Hybrid Power Source For Vehicular Applications

Traditional 14 V battery power source cannot meet the increasing the voltage of electric equipment and power requirements,42 V power supply system,as a kind of voltage upgrade solution arises at the historic moment.The characteristics of vehicular power source such as frequent power consumption and high peak current greatly consume the life of the battery,nevertheless,the use of hybrid power source system(HPSS)can slow down the decay rate of the battery life and achieve efficient energy bi-directional flow.In this paper,a 14/42 V HESS topology is presented based on the complementary advantages of high power density,fast charge and discharge rate of Ultra-capacitor(UC)and high energy density of battery.Furthermore,parameters matching,control strategy designing,modeling and simulation,experimental verification and application expansion are carried out.The research work of this paper as follows:(1)A new 42 V HPSS topology for vehicular applications is proposed,and the series-parallel switching technology is used with bidirectional direct-current to direct-current(DC/DC)power converter.Besides,according to the structural characteristics of the HPS,the working mode is formulated,including boost power supply mode,super capacitor series direct power supply mode,buck regenerative energy mode.(2)Analyze the components of the hybrid power system,establish the hybrid power model,bidirectional DC/DC power converter model,H-bridge DC Pulse width modulation(PWM)converter model and permanent magnet direct-current motor model in Matlab/Simulink,and carry out parameter matching,and verify the high efficiency of the control strategy of the HPS through simulation.(3)Building a low-power experimental platform and matching parameter for 42 V HPSS.Based on TMS320F2812,PWM was carried out for each IGBT switch signal in HPSS.The target current and voltage were controlled by incremental PID real-time,and the working mode was switched according to power consumption.(4)The proposed HPSS is used as the power source system of electric power steering(EPS)system and micro pure electric vehicle respectively.The specific application research is carried out to study the working characteristics of the target system.The modeling and simulation based on Matlab/Simulink is carried out to verify the effectiveness of the proposed 42 V HPSS.Finally,the simulation results verify the feasibility of the 42 V HPSS and the control strategy.Compared with the traditional power source,the 42 V HPSS have great advantages in power performance,cycle life and other aspects,and provides theoretical reference and application value for the follow-up research of the vehicular application.