Four-switch MPPT controller

Abstract

The invention provides a four-switch MPPT (Maximum Power Point Tracking) controller. The four-switch MPPT controller comprises a photovoltaic power supply, a photovoltaic anti-reverse protection unit,a four-switch Buck-Boost conversion unit, a battery reverse connection protection unit and a load control protection unit connected in order; the battery reverse connection protection unit is connected with a storage battery, and the load control protection unit is connected with the battery reverse connection protection unit and the load; the photovoltaic anti-reverse protection unit is used toavoid damaging of the solar controller caused by reverse connection of the photovoltaic power supply; the four-switch Buck-Boost conversion unit is configured to achieve buck and boost of the controller; the battery reverse connection protection unit is used to avoid damaging of the solar controller caused by reverse connection of the storage battery; and the load control protection unit is configured to avoid damaging of the solar controller caused by too large load, reverse connection and short circuit. The four-switch MPPT controller has a buck-boost function, is low in power device voltagestress and few in reactive elements, has the input and output like polarity and common ground, and is suitable for occasions in a wide input voltage range.

Description

technical field [0001] The invention relates to the technical field of solar controllers, in particular to a four-switch MPPT controller. Background technique [0002] As an important component in a photovoltaic power generation system, a solar cell is mainly used to convert solar energy into electrical energy for subsequent battery or load use. For solar cells, its output power-voltage characteristics are non-linear. Under certain environmental conditions, there is a maximum power output, which is called the maximum power point (Maximum Power Point, MPP), and the maximum power point tracking (Maximum Power Point Tracking, MPPT) technology control system is to find the maximum power point of the solar cell, so that the solar cell works at the maximum power point to improve the conversion efficiency of the solar cell. MPPT solar controller is suitable for off-grid solar charging applications, it prevents the battery from being overcharged by the solar module and over-dischar...

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Problems solved by technology

[0003] In order to overcome the deficiencies in the prior art, one of the purposes of the present invention is to provide a four-switch MPPT controller, which solves the problem that both the existing MPPT controller and the PWM controller adopt the step-down mode, that is, the input voltage must be higher than output voltage, and when the input voltage is lower than the output voltage, the controller cannot charge the battery, and the conventional Buck-Boost circuit structure has the characteristics of boosting and bucking, but the voltage stress of the switch tube is too high , The problem that the voltage polarity of the input and output is opposite

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