Research On Generator Controller Of Extened Range Electric Vehicle

Since the beginning of the 21 st century,the world has faced a great challenge from climate change.As the use of fossil fuels increases,so does the concentration of carbon dioxide,leading to extreme weather in many parts of the world.Gasoline car are one of the main sources of carbon dioxide emissions.Therefore,the car of the future should provide society with sustainable economic growth and prosperity.To achieve these goals,the development of vehicles powered by clean,safe energy is critical.In today's numerous vehicle types,electric vehicle because of its zero pollution characteristics,is considered to solve the exhaust pollution of the best model.However,the current problems of short range,long charging time and low battery energy density of electric vehicles have seriously hindered their introduction to the mass market.Therefore,a new type of vehicle is urgently needed as a transition to electric vehicle in order to realize energy saving and environmental protection in the transportation field.The range extender provides electric energy to assist the motor operation,thus solving the problems of limited range,high battery cost and long charging time of electric vehicles,and relieving the dilemma of frequent parking and charging.Compared with fuel oil vehicles,extended-range electric vehicles can significantly reduce the fuel consumption of internal combustion engines to achieve higher fuel efficiency,and have economic,environmental and safety advantages.This paper firstly analyzes the working characteristics of the extended-range electric vehicle,and presents the improvement scheme based on the existing problems.Under the starting state of range extender system,the engineering realization of maximum torque per ampere(MTPA)was studied in order to assist the internal combustion engine to start quickly by using the generator working in electric mode,and an improved MTPA control method was proposed.According to the mathematical model of the d-q axis coordinate system of the Interior permanent magnet synchronous generator(IPMSG),the current distribution relation of d-q axis under MTPA control is derived by using the current space vector and the current phase angle of the permanent magnet flux linkage.Aiming at the problem that it is difficult to solve the stator current with electromagnetic torque,the relation function of torque current is simplified by piecewise curve fitting,and the computing speed of the system is improved.In order to solve the problem of current response deterioration caused by sudden speed change during state switching of the range extender system,the internal mode decoupling was used to compensate the current,so as to eliminate the influence of dynamic coupling.Under Simulink environment,the model simulation of the starting state of the ranger system shows that the improved MTPA control can improve the dynamic response performance of the system and improve the stator current utilization rate,which is conducive to the rapid start of the alternator-assisted internal combustion engine,thus eliminating the need for additional starter configuration.In the power generation state of the range extender system,aiming at the problem that the dual closed-loop control strategy cannot adapt to the PWM rectifier voltage stabilization when the wide load changes,the weak magnetic voltage stabilization control strategy is adopted to enable the range extender system to generate power at constant voltage under the wide load condition.As the simulation based on PWM rectifier dc side shunt load demand driven motor power changing conditions,compare the double closed loop voltage control and weak magnetic voltage regulator control under constant speed wide load conditions of the feasibility of the voltage stabilizing power generation,the simulation shows that weak magnetic voltage regulator control not only improved the ability of system,at the same time increase the power factor and power efficiency.At last,a generator controller based on TI-TMS320F28335 chip is built and the design idea of software algorithm is given.