Regional step-down series-connection common-filtering power optimization photovoltaic module

Abstract

The invention provides a regional step-down series-connection common-filtering power optimization photovoltaic module, and relates to the technical field of photovoltaic power generation systems, which is characterized in that at least two battery units, step-down switch units and a control unit are sequentially connected, and after the outputs of the step-down switch units are mutually connected in series, the step-down switch units are jointly connected into an LC filtering unit for filtering; and each step-down switch unit operates under the control of an independent duty ratio. According to the invention, the efficiency problem of power optimization of a cell string level can be solved, the arrangement of inductors and capacitors is reduced, the capability of processing current ripples of the LC filtering unit is improved by increasing the inductance value, meanwhile, the time occupied by two ends of the inductors at extremely high and extremely low voltage values is shortened due to the independent duty ratio, and the power optimization efficiency of the LC filtering unit is improved. The inductor with the same inductance can be provided with larger current ripples, heat can be dissipated by means of a frame of the module and the like, and the electric power of the photovoltaic module can be comprehensively obtained with low cost, high reliability and high efficiency.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation systems, in particular to a power-optimized photovoltaic module with regional voltage reduction and series common filtering. Background technique [0002] Photovoltaic modules, also known as solar cell modules, or photovoltaic panels. Photovoltaic modules are composed of a certain number of monolithic solar cells arranged in an array structure and sealed in series and parallel to improve the output voltage, avoid electrode and wire corrosion, and achieve reliability and durability. In order to further utilize the power generated by photovoltaic modules, at present, in the photovoltaic concurrent power generation system, its structure is mainly composed of many photovoltaic modules connected into strings, the strings are connected in parallel to form a module array, and converted into alternating current through photovoltaic inverters Implement electricity or grid-connected p...

AI Technical Summary

Problems solved by technology

If there are 12 photovoltaic modules output in series in the photovoltaic power generation system, at least 24 sub-string optimizers will generate harmonic currents and voltages that will superimpose and affect each other, which may cause the optimizer to frequently oscillate back and forth when performing MPPT tracking, reducing the The overall efficiency of the system will cause instability and unreliability of the system at the same time, and will also put forward higher requirements for the output filter inductor and output filter capacitor at the front end of the photovoltaic inverter, which will increase the cost

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