Scenery Complementary Off-grid The Streetlight System Intelligent Controller

Utilization of renewable energy plays an important role in our social and economic sustainable development and environmental protection.Comparisons of wind and solar power are widespread renewable energy,as wind and solar energy have a very good complementary characteristics of resource conditions and technology applications,wind and solar power generation system become an economic and reasonable power supply.Off-grid wind and solar street lighting system as part of its typical applications which to meet the region's public lighting away from the grid with independent power requirements,has important practical value.Therefore,this paper focus on the intelligent controller of off-grid wind and solar street lighting system's design and development to study.Specific work as follows:First of all,introduced the off-grid wind and solar street lighting system structure,analysis the theory and composition of the power generation,power conversion and operation,energy storage consumption parts.Point out that in the intelligent controller,design should be focused on solving the maximum power tracking control strategy and battery charging and discharging control strategy.Second,in terms of the intelligent controller's maximum power tracking control strategy,by analyzing the wind turbines and solar panels working principle and operating characteristics,for the low efficiency of off-grid wind and solar street lighting system's power generation as well as the phenomenon of taking no full advantage of the wind and solar resources,on the basis of summing up and concluding the advantages and disadvantages of various maximum power point tracking (MPPT) algorithms in wind power and solar power systems,this paper uses two-input buck-boost chopper hardware circuit to achieve the wind and solar maximum power output,and uses the variable step control algorithms and improve disturbance observation control algorithms as themselves maximum power point tracking (MPPT) control strategy,that is,the variable disturbance step can be taken place of the traditional fixed-step in the control process,which to improve the efficiency of power generation.Third,in terms of the intelligent controller's battery charging and discharging control strategy,for the phenomenon of incorrect charging and discharging control strategy for shorting the battery life,and on the basis of the analysis of the advantages and disadvantages for various battery charging and discharging methods,with the description of structure principle and working character of the battery,this paper uses the bi-directional DC buck/boost converter to achieve the battery charging and discharging energy management,this method based on the three-stage charging and discharging control,introduces of state of charge (SOC) as a new determined parameter, in order to achieve the purpose of storing more energy,we improve battery acceptable charging current,thus enhancing battery charged level.Finally,according to the system control strategy,we design ATmega16 microcontroller as control core for the Off-grid wind and solar street lighting system intelligent controller.We complete the development and design of many circuits,including voltage and current sampling circuit,the temperature detection circuit,MOSFET drive circuit,the auxiliary power circuit,LCD display circuit,unloading of circuit and protection circuit,also we capture and display temperature,voltage,current for wind turbines,solar panels and batterys;and also complete the software design of system main program,the battery charging and discharging control subroutine,solar and wind power generation control subroutine,variable step MPPT control algorithm and the improved perturbation and observation control algorithm subroutine.The experiments at the scene show that,compared with existing products in a company,solar and wind power output characteristics of the design of the Off-grid wind and solar street lighting system intelligent controller are superior to the existing products,Battery can be realized efficiently,fast,safe charging and discharging control,and has a simple structure and complete protection.