The Design And Research Of Large Photovoltaic Grid Power System's Optimizer

Recently more and more attention has been focused on the photovoltaic power generation because it produces less pollution.A lot of Mountain photovoltaic power stations are being built.PV modules of traditional photovoltaic power stations begin to aging.The problem of performance mismatch between the PV arrays has become more and more serious.Distributed PV array architecture is designed in this years.The key technique of distributed PV array architecture is the intelligent combiner box with MPPT function.The intelligent combiner box with MPPT function is implanted in the photovoltaic power generation system.The high-power optimizer is designed.It is implanted in the traditional internal combiner box to make up the intelligent combiner box.The problem of performance mismatch can be solved by intelligent combiner box.The main research works are as follows:1.Mathematical properties of the PV array is analyzed.The simulink model of PV array is designed.The advantages and disadvantages of conventional MPPT algorithms are analyzed.The simulation models of conventional MPPT algorithm are established.The dual-mode MPPT is designed to improve the power generation efficiency of the system and operational stability.2.The main circuit of power optimizer is designed.Parameters of electronic devices in the main circuit are determined.Hardware circuit of each modules are designed,such as RS-485 communication circuit?STM32 control circuit and IGBT drive circuit.3.The control system of power optimizer is designed based on STM32 chip.Double closed-loop PI control method is applied in power optimizer.The flowcharts of the control system of each modules are designed.4.The circuit diagram of the power optimizer is converted to PCB figure.PC control system is designed to control the power optimizer.The current issue of dual BOOST circuit configuration is verified by prototype testing.The PWM drive signal and maximum power point tracking efficiency are also verified by prototype testing.