Compound power supply control system based on synchronous rectification Buck-Boost bidirectional DC (Direct Current)/DC (Direct Current) convertor

Abstract

The invention discloses a compound power supply control system based on a synchronous rectification Buck-Boost bidirectional DC (Direct Current)/DC (Direct Current) convertor. The system comprises a motor, a motor controller connected with the motor, a storage battery and a super capacitor, wherein the storage battery and the supper capacitor are respectively connected with the motor controller, the storage battery is connected with a power switch and then connected with the motor controller, the supper capacitor is connected with the bidirectional DC/DC convertor and then connected with the motor controller, the power switch comprises two P-channel MOS (Metal Oxide Semiconductor) transistors which are connected in parallel, the bidirectional DC/DC convertor comprises four N-channel MOS transistors and an energy storage inductor, every two of the four N-channel MOS transistors are formed as a half-bridge structure, the two ends of the energy storage inductor are respectively connected with the middle of the two half-bridge structures, the first half-bridge structure is connected with one end of the power switch, the other end of the power switch is connected with one electrode of the storage battery, the other end of the first half-bridge structure is connected with the other electrode of the storage battery, the other electrode of the storage battery is connected with one electrode of the supper capacitor, the second half-bridge structure is connected with the supper capacitor in parallel, and a PWM (Pulse Width Modulation) pulse is added on grids of the N-channel MOS transistors. The system discharges with large power, can be sued for improving the starting, acceleration and climbing performance of electromobiles, and prolonging the service life of the storage battery, and can charge with large power, so as to rapidly recycle the energy during the regenerative braking of the electromobiles and increase the driving mileage of the electromobiles on a single charge.

Description

technical field [0001] The invention relates to the field of on-board power supplies for electric vehicles, relates to a composite power supply control system for electric vehicles, in particular to a composite power supply control system based on a synchronous rectification Buck-Boost bidirectional DC / DC converter. Background technique [0002] With the rapid development of the automobile industry, energy crisis and environmental crisis have become the two most prominent themes in today's society. According to the survey, the annual fuel consumption of all kinds of vehicles in the world is about 700 million tons. According to this ratio, the oil resources in the world can only last for 50-70 years; and 63% of the urban air pollution comes from fuel oil. Exhaust emissions from cars. Therefore, under the pressure of these two major crises, electric vehicles came into being. [0003] However, the poor performance of batteries used in electric vehicles leads to short mileage ...

AI Technical Summary

Problems solved by technology

However, the bidirectional DC / DC converter used here can only perform step-down charging and step-up discharge on the supercapacitor. The supercapacitor works in a low-voltage mode, so that when the back electromotive force of the motor is low, the supercapacitor cannot be charged, and its energy recovery efficiency Low, which weakens the regenerative braking capability of the supercapacitor

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