Research On The Maximum Power Of The Branch Series Voltage Source Under Local Shadow Conditions

In the photovoltaic array,the local shadow will cause a hot spot effect to cause a large amount of damage to the photovoltaic equipment,at the same time it will cause a reduction in output power,and make the photovoltaic output characteristic curve appear multi-peak,making the traditional maximum power tracking algorithm invalid.The improved maximum power tracking algorithm can accurately find the maximum power point of the photovoltaic array,but it does not solve the problem of reduced output power of each branch caused by local shadows.Therefore,through the improvement of the photovoltaic system’s own structure,this study can have a better system improvement effect than the algorithm improvement,and ultimately improve the quality of the energy output of each branchDue to the influence of local shadows,the voltage of each branch in the parallel circuit to reach the maximum power point is different,but the voltage of each branch in the parallel circuit is equal,which also causes the It is impossible to achieve the maximum power point for all branches at the same time.Therefore,this article chooses to connect a controllable voltage source in series in each branch,and perform voltage compensation so that each branch can work at the maximum power point voltage,so that the system can output maximum power.In the improvement of the structural scheme,this paper first obtains the maximum power point voltage of each parallel branch through the light sensor,and uses the maximum voltage as the output voltage of the photovoltaic array.After calculation,the voltage to be compensated for each branch can be obtained.The output voltage of the photovoltaic array is used as the input voltage of the step-down chopper.The voltage sensor is used to compare the voltage of each branch with the reference voltage.After passing through the PI regulator,the pulse signal is compared with the triangular wave to control the switch on and off To perform voltage compensation for each branch.Each branch can work under its own maximum power point voltage and output maximum power.Then it is compared with the GMPPT method for simulation,and its feasibility is proved by Matlab simulation.The method is simple,easy to operate,and has practical research value.In the experiment,Matlab simulation was carried out on the photovoltaic array of[4 × 4].During the simulation process,the compensation voltage was applied to the branches.The final output power of the photovoltaic array was 745 W.Although there is a little difference from the output power under absolute ideal conditions,the comparison In terms of the system output power simulated by the particle swarm optimization algorithm,the power is increased by about 16%.Moreover,the experimental method is relatively simple and easy to operate.The main loss of the overall experiment is to compensate the switching loss in the voltage system.Therefore,it is relatively economical and has very practical research value.