Switching method applied to charging module transformer winding switching device

Abstract

The invention discloses a switching method applied to a charging module transformer winding switching device. A high-frequency transformer, a switching tube, a controller, a driving circuit and a high-frequency inverter circuit are included. Three taps are arranged on the secondary side of the high-high frequency transformer, two taps are connected with switching tubes which are connected in series reversely, and the controller controls the high-frequency inverter circuit and the switching tubes through a driving circuit; and the controller adjusts the control quantity of the high-frequency inverter circuit according to the winding switching proportion, executes a four-step current conversion method at the same time, and controls the switch-on or switch-off of the switching tube, and the winding is switched from high voltage to low voltage or from low voltage to high voltage. According to the invention, flexible seamless switching between windings is realized, peak voltage is eliminated, and the service life of a switching tube is prolonged; the controller judges the directions of the secondary winding currents is1 and is2 according to the control quantity of the high-frequency inverter circuit, the current direction does not need to be judged through a detection circuit, and the circuit structure is simplified; the converter realizes continuous high-power output in different output stages, and the efficiency of the converter is improved.

Description

technical field [0001] The invention relates to the technical field of power electronics and control, in particular to a switching method applied to a transformer winding switching device of a charging module. Background technique [0002] With the development of the new energy vehicle industry, the voltage range of electric vehicle batteries is gradually expanding. High-power DC charging equipment must meet the charging needs of different types of electric vehicles and meet the wide voltage range output of 200V-1000V. Traditional transformers mostly adopt the secondary single-winding topology scheme, and the output voltage range is between 200V and 800V. It is difficult to meet the full power output in such a wide range in a single working mode. [0003] The existing method proposes to use a transformer secondary winding topology, which has been widely used. However, it uses a relay as a switching device, and the response speed of the relay is relatively slow. The winding m...

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Problems solved by technology

Traditional transformers mostly adopt the secondary single-winding topology scheme, and the output voltage range is between 200V and 800V. It is difficult to meet the full power output in such a wide range under a single working mode.

[0003] The existing method proposes the use of transformer secondary dual-winding topology, and has been widely used, but it uses relays as switching devices, and the response speed of relays is relatively slow, and the windings must be switched after shutdown, which cannot achieve seamless switching

[0004] The existing method proposes to use power devices such as MOS and IGBT as the switch tube, and when switching from high voltage to low voltage, or from low voltage to high voltage, the switch tube of one coil can be turned off before the switch tube of the other coil can be closed. This control strategy will When the switch tube is turned off, the output current loop of the transformer is suddenly cut off, resulting in a large voltage spike and damaging the switch tube

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