| In recent years,due to the energy crisis and environmental problems,countries all over the world have sought energy transformation and development.Photovoltaic power generation technology has developed rapidly because of its ability to make full use of clean and renewable solar resources.The large-scale promotion and application of this technology is very important for "Beautiful China" and The achievement of the goal of “carbon peak and carbon neutrality” is of great significance.Under normal circumstances,the output voltage of photovoltaic cells is low,the voltage fluctuation range is large,the work has the disadvantages of intermittent and randomness,and the power generation is easily affected by the external environment such as temperature and light,and the electrical performance of photovoltaic cells of different materials varies greatly.Therefore,the energy storage unit is introduced to smooth the power fluctuation and develop an optical storage inverter with wide input characteristics.First of all,this article conducts in-depth analysis and research on the working principle and steady-state performance of the single-tube high-gain DC/DC converter in the front stage of the optical storage inverter,and derives and gives the steadystate performance and duty cycle of the converter.At the same time,compare and analyze with each converter.In order to further expand the voltage range that photovoltaic cells can be connected to,and better compatible with the access of conventional crystalline silicon and photovoltaic cells of new materials,multi-level expansion of the converter topology is provided,and the expansion of the number of stages,duty cycle and steady-state performance are given.At the same time,the correctness of theoretical analysis and calculation is verified through simulation experiments.Secondly,the topology and working principle of the optical storage inverter with highly multiplexed switching tubes are analyzed,and its typical operating waveforms are given.The current ripple analysis is performed on the battery ports using the interleaved parallel Buck-Boost technology,and the ripples are given.Bobby relationship curve.Combining actual application scenarios,divide the system working mode and power transmission mode to provide a reliable basis for the establishment of the mathematical model of the system.On the basis of the built wide-input optical storage inverter model,a multiobjective control strategy based on model predictive control(MPC)is designed,the corresponding predictive model and cost function are derived and established,and the appropriate MPPT control method is selected based on the output characteristics of the photovoltaic cell.The system control flow chart realizes photovoltaic MPPT,battery charging and discharging control and inverter output power control.At the same time,the verification of the effectiveness of the system control strategy is completed through simulation experiments.Finally,through the design of related hardware circuits,a hardware experimental platform for the wide-input optical storage inverter system is built,and the performance indicators of the high-gain DC/DC converter and the photovoltaic cell MPPT control are experimentally verified,and the wide-input optical storage inverter is tested.The operating conditions of the converter in each working mode verify the effectiveness and feasibility of the multi-objective control strategy based on model predictive control. |
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