Design And Implem Of Controller Of Solar Garden Lamp

Lighting occupies a large proportion in the whole energy consumption ofelectricity and it maks people eager to find a way of green lighting.Solar energy which is a new clean energy combined with LED light makes use of this way possible.Solar LED lamp has many advantages compared with other lighting,such as green environmental protection,energy saving and emission reduction,long service life and so on.This paper designs a solar garden lamp controller to control the battery charging and the LED lamp lighting.Because the output of the solar energy is nonlinear and it changes everytimes when the temperature and the light have changed,it needs a way of most power point tracking to make it always output the most power.Basing on the analysis of the solar output characteristics,this paper presented a tracking algorithm that is SFCMPPT and has analysised specific control flow of algorithm.Firstly,this paper compares several commonly used solar maximum power point tracking (MPPT) control mode, summarizes their advantages and disadvantages in the basis, the paper uses SFCMPPT as the maximum power point tracking scheme, the solar cell output is still in the vicinity of the maximum power point, and designed the control flow of the algorithm.Secondly, this paper introduces the working principle and characteristic of battery, and several battery charging ways, based on summing up the advantages and disadvantages of these charging the battery charging process, research and choose the way of charging of the design.Thirdly, the design for the electrical characteristics of the white light LED and the actual situation, using peak current mode controlled BUCK-BOOST converter as its constant current driver, and analyzes the necessity of the current stability and slope compensation converter, MAX16834 is selected as the constant current control chip.Finally, this paper designs a bidirectional energy flow of BOOST-BUCK main circuit, the circuit works in the charging mode is equivalent to the BOOST-BUCK circuit, working on the discharge mode equivalent circuit for BUCK-BOOST. Driven by way of bootstrapping to make the circuit has a peripheral device at least. The overall control of the flow of the whole system are analyzed.