Vehicle-mounted composite power supply regenerative braking energy recovery system and method

Abstract

The invention discloses a vehicle-mounted composite power supply regenerative braking energy recovery system and method. A supercapacitor and a bi-directional DC / DC converter are connected in series to form an auxiliary energy source. A storage battery and a normally closed relay are connected in series to form a main energy source. The main energy source and the auxiliary energy source are connected in parallel with the output end of a permanent magnet brush direct current motor. The output end of a single chip microcomputer is connected to the bi-directional DC / DC converter. The bi-directional DC / DC converter is composed of an inductor L, IGBT (Insulated Gate Bipolar Transistor) tubes S1, S2 and S3 and diodes D1, D2 and D3. When a vehicle is in normal running, the relay is in a normally closed state, the normally closed relay is cut off to cut off the connection between the storage battery and the permanent magnet brush direct current motor after a brake pedal acts, and the permanent magnet brush direct current motor feeds regenerative braking energy back to the supercapacitor through the bi-directional DC / DC converter. The vehicle-mounted composite power supply regenerative braking energy recovery system and method can make full use of the situation that the counter potential of the permanent magnet brush direct current motor is lower than the braking energy of the supercapacitor voltage end in a braking process to effectively improve the recovery efficiency of the regenerative braking energy.

Description

technical field [0001] The invention belongs to the field of hybrid electric vehicles, and in particular relates to a composite power source regenerative braking energy recovery system and method for hybrid electric vehicles. Background technique [0002] With the rapid development of the automobile industry, energy issues and environmental issues have become global concerns. In this context, the vehicle-mounted composite power supply consisting of a high specific energy battery and a high specific power supercapacitor has become one of the current research hotspots. At this stage, the problems to be solved in the on-board composite power supply regenerative braking energy recovery system are mainly reflected in: how to achieve safe and rapid recovery of regenerative braking energy within the allowable range of vehicle volume and cost; how to improve regenerative braking energy under different conditions. Braking energy recovery efficiency. [0003] In the existing braking...

AI Technical Summary

Problems solved by technology

[0003] In the existing braking energy recovery system, common power devices are used to connect the battery to the vehicle motor, and a bidirectional DC / DC converter with a non-isolated half-bridge structure is used to connect the supercapacitor to the vehicle motor; this braking energy recovery system The disadvantages are: first, the power device undoubtedly needs to be equipped with a corresponding control module, and the power device itself has energy loss; second, the bidirectional DC / DC converter can only perform step-down charging and step-up discharge for the supercapacitor. Braking energy cannot be recovered when the back EMF of the motor is lower than the terminal voltage of the supercapacitor

Although the bidirectional DC / DC converter with this structure can realize the buck-boost charging and discharging of the supercapacitor, so that the braking energy can be utilized when the back electromotive force of the motor is low, but the control of the four MOS tubes is more complicated, and The power tube itself also produces energy loss

The Chinese patent application number is 201410293988.5, titled "A N-PMOS switch decoupling electric vehicle composite power supply and energy control method" proposes a bidirectional DC / DC converter composed of three power tubes, although the power tubes The number can be reduced, but this structure is only applicable to the situation where the voltage level of the super capacitor is higher than that of the battery. Because the voltage level of the super capacitor is higher than that of the battery, it will bring about an increase in cost and a safety hazard in the vehicle energy supply system. use less

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