Design Of MPPT Controller For Solar Traffic Lights

For traffic lights and other equipment in the field of transportation,because of the particularity of its outdoor environment,photovoltaic(pv)power supply has the advantages of the energy conservation environmental protection,and cost savings.especially for lack of power supply in remote areas,photovoltaic(pv)power supply for traffic equipment is advantageous obviously.For photovoltaic power supply system,the photovoltaic maximum power point tracking(MPPT)controller is one of the key technologies,which is of great significance to improve the efficiency of the entire photovoltaic power generation system.Aiming at the characteristics of the traffic light equipment power supply photovoltaic power supply system,MPPT tracking controller based on ARM platform is designed.This paper analyzes the principle of photovoltaic power generation,the equivalent circuit model is designed and the matlab/simulink simulation model is set up,foreign output characteristic is studied.Through the establishment of simulation model,the voltage-current and voltage-power output characteristic curve is obtained,the characteristics of the maximum power point tracking control of a photovoltaic cell analysised and researched.Applicable occasions,the advantages and disadvantages of various traditional commonly used for MPPT control algorithm are compared and researched.On base of the full study of the regular perturbation method step change characteristics,the multiple state variable step perturbation method is proposed.This method could be divided into five kinds of step change state,according to certain rule change step.In the matlab/Simulink simulation model is set up,validity of the control algorithm is test,strong theoretical support for MPPT controller design is provided.For load changing topological structure and performance,similarities and differences of the commonly used Buck and Boost topology are compared,analyzing the characteristics of the respective features and applicable.Finally the Boost topology as the basis of load changing topology structure is better;Physical system hardware and software is designed,on the one hand,based on Boost circuit topology of main circuit,lightning protection,over current protection design are made carefully;the selected controller is introduced,the driving isolating circuit,control circuit,voltage and current sampling circuit,etc.is designed;Especially the recovery over-current protection circuit and auxiliary power control circuit,reduce the maintenance burden and human intervention in general malfunction.Software code is made and debugged,including system initialization,PWM generation module,AD conversion module,and the watchdog software protection at the same time,and the key test point parameters are analyzed.Experiment is simulated,and the light from one order of magnitude step transform to another level,at the same time the contrast experiment is set.The result of general perturbation method and the optimized disturbance method of control is collected,and voltage output,current output of the system parameters is observed,generalization analysis was carried out on the experimental data.The results show that the disturbance variable step length control based on multiple state can quickly identify and track the maximum power point of pv cells,fast response to outside conditions change,high control precision,strong anti-jamming capability,which prove out the correctness and effectiveness of this control scheme design.