Research On Three-port Converter Circuit For Photovoltaic Electric Vehicle

In recent years,the global energy crisis and environmental pollution problems have become increasingly serious,and traditional fuel vehicles are increasingly unable to meet the needs of the times.The combination of renewable energy and traditional cars has become a research hotspot,and photovoltaic electric vehicle that use solar energy as a primary energy are one of them.However,due to low photoelectric conversion efficiency of photovoltaic cells,low integration of power conversion circuits,and slow response of motor load speed control,the development of photovoltaic electric vehicls is restricted.In order to reduce the size of the photovoltaic electric vehicle power supply circuit,improve its power conversion efficiency and the speed regulation performance of the motor,this paper proposes a three-port topology based on bidirectional Sepic-Zeta for photovoltaic electric vehicle and optimizes the speed control method of photovoltaic electric vehicle motor.The main research contents are summarized as follows:1)Based on the operating principle of photovoltaic electric vehicle,this article analyzes the principle of the main components of photovoltaic electric vehicle,such as photovoltaic cells,batteries and motors,and selects their types.Based on these,the energy distribution principles and system control strategies of photovoltaic electric vehicles are proposed.Based on the operation requirements of photovoltaic electric vehicle,a three-port conversion circuit based on bidirectional Sepic-Zeta is proposed for photovoltaic electric vehicle power supply circuits,and the switching model and steady-state characteristics are analyzed.2)Simulink is used to simulate the power supply circuit of photovoltaic electric vehicle,and the effectiveness of the topology and control strategy is verified.Aiming at the difficulty of judging the operating mode of photovoltaic electric vehicle,a control method that predicts the maximum output power of photovoltaic cells based on light intensity and temperature is proposedto determine the system's operating modeby comparison with load rated power.For the inductive loads such as motors,the output port voltage of the three-port conversion circuit under PI control has the problems of slow adjustment speed and large steady-state error.The PI control method is optimized using BP neural network.Simulation results show that the PI control method based on BP neural network reduces the adjustment time and steady-state error of output port voltage.3)For the photovoltaic electric vehicle motor speed adjustment and load disturbance suppression,a radial basis functionneural PID control method is proposed,which is compared with the fuzzy PID control method.The simulation results show that the PID control method based onradial basis function nerve is faster in speed adjustment and more resistant to load disturbances.4)According to the design requirements of photovoltaic electric vehicle,the parameters of the three-port conversion circuit are calculated,and the hardware design of the main circuit and peripheral module circuit of the three-port conversion circuit and the software design of the control system are carried out.