Fan rotating speed control system and method for electric vehicle battery charger

Abstract

The invention provides a fan rotating speed control system for an electric vehicle battery charger. The fan rotating speed control system comprises a control device and charging modules, wherein the control device and the charging modules are connected through a CAN bus. Relevant parts in each charging module of the fan rotating speed control system comprise a core processor, a CAN bus communication circuit, a fan control unit, fans and a temperature measuring unit, wherein the fan control unit is connected with the fans through fan power input circuits correspondingly and connected with the temperature measuring unit and the CAN bus communication circuit through the core processor. According to the technical scheme provided by the invention, the stability of the rotating speed of the fans is enhanced, fan operating noise is lowered, and the fan fault diagnosis accuracy is improved.

Description

technical field [0001] The invention relates to the speed control of a fan, in particular to a fan speed control system and a control method for an electric vehicle charger. Background technique [0002] The electric vehicle charger adopts a modular configuration. Under the monitoring of the control device, multiple charging modules of the same type in the cabinet operate in parallel; the charging module is air-cooled, and the air inlet is equipped with a fan. Enter, pass through the internal air duct, and be discharged from the air outlet on the back panel of the charging module; the fan adopts a conventional 2-wire brushless DC fan, and the fan speed is controlled by the core processor in the charging module according to the heat sink of the power device in the charging module. The temperature is controlled, and the speed of the fan is generally divided into 2 to 3 gears; the control method of the fan is a simple open-loop control, and the core processor cannot know the fa...

AI Technical Summary

Problems solved by technology

[0004] After the over-temperature alarm of the charging module, it is necessary to manually find the fan that is stalled or the speed is too low, and then replace it; the fan is jammed or the input voltage is low, which can cause the fan to stop or the speed is too low, and the speed of the fan cannot be checked visually. In addition, it cannot be measured accurately, which leads to over-reliance on experience in the process of dealing with fan failures, and it is difficult to avoid deviations in the identification of failed fans

[0005] The temperature of the power device in the charging module is measured by the core processor through the temperature measuring element, which usually uses a thermistor; the consistency of the thermistor temperature measuring element is very poor, and the resistance-temperature curve has serious nonlinearity ;Due to the inconsistency of temperature measurement data, the speed of the fans in each charging module cannot be unified. Because there is a current equalization circuit between each charging module, the output power of each charging module is basically the same, which eventually causes some charging modules to run at high temperature for a long time , premature failure

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