Vehicle power supply system and working method thereof

Abstract

The invention discloses a vehicle power supply system and a working method thereof. A power source is connected to a power module which is connected to a transformer; the transformer is connected to a rectification filtration module; the rectification filtration module is connected to a low voltage device and a battery; an MCU (Micro Controller Unit), an analog-to-digital converter and a digital-to-analog converter which collect voltage and current signals control a current feedback loop, a voltage feedback loop and a charging current feedback loop; the current feedback loop, the voltage feedback loop and the charging current feedback loop output to the input end of the a PWM (Pulse Width Modulation) controller to control the output duty ratio of the PWM controller. The vehicle power supply system and the working method thereof have the advantages of overcoming disadvantages of the prior art, guaranteeing the power demand of the vehicle low voltage device and guaranteeing the service life of the battery.

Description

technical field [0001] The invention belongs to the field of current conversion, and specifically designs a vehicle power supply system from high voltage to low voltage for vehicles and a working method thereof. Background technique: [0002] In a hybrid vehicle, the low-voltage generator is very inefficient for charging the battery. Therefore, in order to improve the fuel saving rate, the low-voltage generator will be replaced with a more efficient power supply system, that is, a DC converter. After the energy is converted, it charges the low-voltage battery and supplies power to the low-voltage system of the whole vehicle at the same time. At this point, a contradiction arises. If the power of the power supply system is too large, the charging current of the battery will be too large, which will seriously affect the life of the battery; The power demand of the system. The traditional low-voltage power supply system for vehicles is controlled by a PWM controller to genera...

AI Technical Summary

Problems solved by technology

At this time, a contradiction arises. If the power of the power supply system is too large, the charging current of the battery will be too large, which will seriously affect the life of the battery; System Power Requirements

The traditional low-voltage power supply system for vehicles is controlled by a PWM controller to generate a PWM-driven switch tube to form a high-power square wave, which is converted into a required square wave pulse by a transformer, and then rectified and filtered to form a required DC output. The output voltage and current are then passed through The feedback loop conditioning is sent to the PWM controller to control the PWM duty cycle. However, since the output current of the power converter can only be a maximum limit value, when it is used for the vehicle system, too much current will seriously shorten the battery life. life, the current is too small to meet the power supply demand

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