Vehicle control strategy of series hybrid electric vehicle

Abstract

The invention discloses a vehicle control strategy of a series hybrid electric vehicle, namely a strategy for judging series driving mode entering or exiting according to electric quantity of batteries. An electric quantity increasing mode, an electric quantity balancing mode and an electric quantity consuming mode are respectively defined in a series driving mode. The electric quantity increasing mode, the electric quantity balancing mode or the electric quantity consuming mode depends on the electric quantity of the batteries, the major failure existing situation of and the batteries and the high-power demand condition. Output torque and demanded power of a driving motor are calculated according to vehicle frictional resistance, gradient resistance, windward resistance and accelerated inertial resistance, and an auxiliary energy unit and output power of the batteries are analyzed and adjusted by adopting the control strategy in the electric quantity increasing mode, the electric quantity balancing mode and the electric quantity consuming mode. By adopting the vehicle control strategy, the energy demand distribution situation of the series hybrid electric vehicle in the series driving mode. The vehicle control strategy is suitable for vehicle acceleration, climbing and other high-power demands and battery failure warning occasions and meets the requirements for power performance, a failure protection function of a system.

Description

technical field [0001] The invention relates to a vehicle control strategy of a series hybrid electric vehicle. Background technique [0002] With the development of the automobile industry, more and more hybrid vehicles are used, among which the series hybrid vehicles are driven by the engine and the drive motor, such as figure 1 Shown is the energy conversion relationship between the subsystems of a series hybrid electric vehicle, where the dotted line is the mechanical energy transfer, and the solid line is the electrical energy transfer. The engine and generator are usually analyzed as a whole, referred to as the auxiliary power unit (APU), which is Auxiliary device for vehicle supplementary electric energy; drive motor consumes electric energy, and brakes to recover electric energy; battery and super capacitor are only energy storage devices that do not generate energy; chargers and charging piles convert commercial power into high-voltage direct current and store it in...

AI Technical Summary

Problems solved by technology

This working mode can effectively avoid battery overcharging and discharging operations, but the energy distribution relationship is too single, and the power performance and fault protection function of the system cannot meet the requirements in the case of high power demand such as car acceleration and climbing, or severe battery failure.

Therefore, the series drive mode of the series hybrid electric vehicle has an unreasonable allocation of energy demand. The auxiliary energy unit is basically charged at a constant power, and the output power of the battery is constantly changing with the power consumption of the drive motor. This energy distribution method cannot be applied to all driving of the vehicle. Condition

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