Maximum Power Point Tracking For PV Array Under Partially Shaded Conditions Based On Glowworm Swarm Optimization Algorithm

Characterized by its directness in source,great potential in development,the inexhaustible and the most widely distributed solar energy is gradually becoming the world's most important clean energy.How to use photovoltaic array to produce stable,efficient and continuous power is an important research content in the field of photovoltaic power generation.The PV module indeed is a non-linear DC current source whose output is affected by the angle and intensity of solar radiation and ambient temperature.However,in the real working environment,PV module tends to be blocked by tall buildings,trees,clouds and particles on the surface of the array so that it works partially in shadows.When it is blocked severely,"hot spot effect” will occur,resulting in the damage of the arrays.The results show that the parallel bypass diodes at both ends of the PV array can effectively prevent the severe consequences of the " hot spot effect”,but the P-U output characteristic curve will present a number of extreme points.In this case,the traditional maximum power point tracking(MPPT)algorithm may lead to the partially optimal solution.Therefore,the problem of maximum power point tracking of photovoltaic array under partial shadow is studied in this paper.The specific aspects of the research are as follows.First of all,through the simulation model of PV array which is extended in Matlab or Simulink from the mathematical model of solar cell,and analyzing the output characteristic curve,the feasibility of simulation model is verified.Secondly,by comparing and analyzing a large number of characteristic curves,the corresponding relationship between the distribution characteristics of the extreme points and the structure of the PV array can be worked out,thus improving the efficiency of the MPPT algorithm.Thirdly,The traditional MPPT algorithm is compared with MPPT algorithm in partial shadow,the areas applied by these algorithms can be analyzed.Glowworm swarm optimization algorithm is proposed in this paper to solve the MPPT problem in partial shadow and meanwhile,original GSO algorithm is improved.Fourthly,each module of the MPPT controlling system is built,and their parameter are set and then,a complete MPPT controlling system in partial shadow is made.Finally,by comparing the results of MPPT algorithm in the partial shadow and improved GSO algorithm simulation,the paper has obtained results based on which this algorithm is better than other algorithms in resource occupancy rate,operation time,convergence precision.