High-transformation ratio isolated solar charging controller with MPPT function

Abstract

The invention relates to a charging controller technology, in particular to a high-transformation ratio isolated solar charging controller with a maximum power point tracking (MPPT) function. The controller comprises a microprocessor, a pulse width modulation (PWM) unit and a switching tube unit, and also comprises a first voltage sampling circuit, a first current detection circuit, a second voltage sampling circuit, an isolation driving circuit and a high-frequency switching transformer, wherein the first voltage sampling circuit is used for sampling an output voltage of a solar battery; thefirst current detection circuit is used for sampling an output current of the solar battery; and the second voltage sampling circuit is used for sampling a voltage of a storage battery. The controller can realize dual intelligent charging control of MPPT+ system on chip (SOC); moreover, the controller can avoid a breakdown accident and a thermal damage accident of the switching tube when the output voltage of the solar battery is very high but the voltage level of the storage battery configured by a user is very low; therefore, the controller is suitable for solar power generation systems, such as an amorphous silicon membrane solar battery power generation system, with a very high solar battery output voltage and a very low storage battery voltage level.

Description

technical field [0001] The invention relates to charge controller technology, in particular to a large transformation ratio isolated solar charge controller with MPPT function. Background technique [0002] As the earth's resources become increasingly scarce and the investment cost of basic energy is rising day by day, people begin to pay more and more attention to the application and development of solar energy. Solar energy is both primary energy and renewable energy. It is rich in resources and can be used for free without transportation. It has no pollution to the environment. It has created a new form of life for human beings, enabling society and human beings to enter a state of energy conservation and reduction. The age of pollution. [0003] At present, most of the solar charge controllers are step-down charge controllers based on Buck (step-down conversion) circuit topology, which directly use the switching tube circuit to step down the output voltage of the solar ...

AI Technical Summary

Problems solved by technology

A fatal flaw of this type of solar charge controller is that when the output voltage of the solar cell is very high and the battery voltage level configured by the user is very low, for example: when using a thin-film solar cell, the output voltage of a single thin-film solar cell can be As high as 100V, and the user configures a battery with a voltage level of 12V, there is a huge voltage difference of 80V between the input voltage and output voltage of the charge controller; when using PWM charging, the huge voltage difference of 80V is multiplied by the current It is the loss of the switch tube. It is conceivable how huge this loss is, which will cause the switch tube to heat up extremely, and the temperature of the switch tube will rise sharply, which will easily lead to the breakdown of the switch tube in the charging circuit and the occurrence of thermal damage accidents.

Therefore, under the above circumstances, conventional Buck-type solar charge controllers are difficult to meet the requirements of users

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