Research On Vehicle-borne Photovoltaic Micro-Inverter Power Supply

In this paper,the vehicle-mounted photovoltaic micro-inverters are taken as the research object,and the main circuit topology of the vehicle-mounted photovoltaic micro-inverters is determined by analyzing the performance indicators and technical requirements of the photovoltaic micro-inverters.It is mainly divided into three modules: photovoltaic maximum power tracking and charging module,push-pull high frequency inverters and boost isolation module and AC-DC-AC output module.Photovoltaic battery is a kind of on-board power supply.The efficiency of photoelectric conversion is a very important index.So three typical maximum power tracking methods of solar energy are studied.Buck chopper circuit and maximum power tracking technology are combined,and the charging current of lithium battery pack is used as load adjustment parameter.Through the comparison of simulation experiments,it is proposed that the control strategy of staged charging of lithium batteries by conductivity increment method is more ideal.In order to satisfy the 220V/50 Hz AC output of the inverters,the push-pull high frequency inverters and transformer boost circuits are used to boost the 12 V DC current of lithium battery packs.A 10 kHz multi-resonant PWM signal generator is designed for the timing management of the switching control of the high frequency inverters.The output stage full bridge inverter circuit adopts double closed loop feedback regulator control.In this paper,three kinds of voltage stabilization and inversion control strategies,i.e.double closed-loop PI voltage stabilization control,double closed-loop fuzzy PI control and double closed-loop single neuron PI control,are studied and designed from the control principle,control rules and control algorithm.Finally,the control effects of the three control strategies are verified by simulation,and the single neuron adaptive PID voltage stabilization based on RBFNN identification is determined.Inverter control method is the control strategy of this application problem.This method can solve the problem of difficult parameter setting and poor dynamic response,and control the harmonic distortion THD within a certain index.According to the technical and performance requirements of vehicle-mounted photovoltaic inverters,parameters calculation and system design including main circuit and control circuit are carried out.The calculation of main circuit parameters and the selection basis of main circuit components are given.The control system is designed according to three main functional links: solar panel power tracking and lithium battery charging management,fixed high frequency inverters and transformer boost and output stage inverter control,and the simple function test of the prototype is carried out.