Control method and device of power converter, and storage medium

Abstract

The invention discloses a control method and device of a power converter, and a storage medium, and the method comprises the steps: determining a target duty ratio of a second upper bridge arm switching tube when the input voltage of a voltage input unit is greater than the output voltage of a voltage output unit, according to the target duty ratio, the conduction duration of the first upper bridge arm switch tube is controlled so as to adjust the duty ratio of the first upper bridge arm switch tube, the duty ratio of the first lower bridge arm switch tube is complementary with the duty ratio of the first upper bridge arm switch tube, and the duty ratio of the second lower bridge arm switch tube is complementary with the duty ratio of the second upper bridge arm switch tube; when the input voltage of the voltage input unit is equal to the output voltage of the voltage output unit, the duty ratio of the first upper bridge arm switch tube is fixed, and the conduction duration of the second lower bridge arm switch tube is controlled until the input voltage is smaller than the output voltage and the output voltage is not increased any more. According to the invention, seamless switching of the four-switch DC / DC power converter can be realized conveniently and efficiently, and switching loss is reduced.

Description

technical field [0001] The present application relates to the field of power electronic control, in particular to a control method, device and storage medium of a power converter. Background technique [0002] The four-switch DC / DC power converter has been widely used in applications that do not require isolation due to its small number of switching devices and the ability to achieve bidirectional energy flow. Although the four-switch DC / DC power converter has only four switching devices, the control strategy is extremely complex. For example, the entire control area can be divided into three modes: BUCK, BUCK-BOOST, and BOOST according to the relationship between input voltage and output voltage, and then However, in this control strategy, there will be an intersection between the three modes when switching, which will lead to a decrease in the control performance of the power converter. For another example, the four-switch DC / DC power converter can be regarded as a BUCK b...

AI Technical Summary

Problems solved by technology

Although the four-switch DC / DC power converter has only four switching devices, the control strategy is extremely complex. For example, the entire control area can be divided into three modes: BUCK, BUCK-BOOST, and BOOST according to the relationship between input voltage and output voltage, and then The adjustment of the output voltage is completed by switching the mode, but in this control strategy, there will be an intersection between the three modes when switching, which will lead to a decrease in the control performance of the power converter.

For another example, the four-switch DC / DC power converter can be regarded as a BUCK bridge arm connected in series with a BOOST bridge arm, and controlled according to the BUCK-BOOST (buck-boost) mode, and the output voltage is realized by adjusting the duty cycle. adjustment, but in this control strategy, since the four switching tubes are performing a wide range of switching actions, the switching loss is large and the efficiency is low

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