Electric automobile dynamical system with precharge circuit and control strategy

Abstract

The invention aims at the characteristics and the existing problems of an existing electric automobile adopting an energy storage structure that a dynamical battery is connected with a super capacitor in parallel and designs an electric automobile dynamical system with a precharge circuit. With the adoption of the electric automobile dynamical system, optimized management can be carried out on vehicle electric energy. The electric automobile dynamical system comprises the dynamical battery and the super capacitor and is characterized in that the super capacitor is connected with a main motor system in parallel; the dynamical battery is connected with the main motor system in parallel after being connected with a contactor K1 in series; an auxiliary motor system is connected with the dynamical battery in parallel; the auxiliary motor system is connected with the main motor system in parallel after being connected with a charge resistor and a contactor K2; and an engine is connected to the auxiliary motor system. The invention also provides a corresponding control strategy so as to achieve the purposes of meeting the demand of the driving conditions, furthest utilizing the energy stored by the super capacitor, making the dynamical battery to avoid large current and deep discharge, improving system efficiency and ensuring the service life of the battery and the super capacitor.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a power system of the electric vehicle. Background technique [0002] The most commonly used energy storage devices for existing electric vehicles are power batteries and supercapacitors. The power batteries are used as the main electric energy storage device, and the supercapacitors are used for vehicle operating conditions such as vehicle starting or braking energy recovery, such as instantaneous high-current charging and discharging. [0003] The easiest way is to directly connect the power battery and the super capacitor to the vehicle power line in parallel, which weakens the charging and discharging capacity of the super capacitor, and in order to achieve the effect of using the super capacitor independently, the capacity of the super capacitor must be increased. Make cost and volume all increase greatly. [0004] An improved way is to use a high-current relay to...

AI Technical Summary

Problems solved by technology

However, frequent high currents will cause damage to the power battery, and the number of power battery cycles is relatively large, resulting in shortened life, low efficiency, and insufficient energy absorption by the supercapacitor

A two-quadrant DC / DC converter between the power battery and the supercapacitor can improve the energy utilization rate of both, but the DC / DC converter has high requirements and is expensive, which will significantly increase the cost of the entire system

In addition, in extreme cases, the power of the power battery and the supercapacitor may not be sufficient to meet the needs of the motor. How to choose the corresponding control strategy is also a problem that needs to be considered.

Images