Method for controlling dynamic derating of hybrid electric vehicle based on thermal model

Abstract

The invention discloses a method for controlling dynamic derating of a hybrid electric vehicle based on a thermal model. The method comprises the following steps of: establishing an entire vehicle motion model and an electric driving power model; and establishing a thermal model which is partitioned into three levels, wherein a first level is used for measuring the temperature rise of each part based on a 3D (three-dimensional) part thermal model; a second level is an electric driving level thermal model which is used for establishing a thermal resistance network system model of each part by using the analysis result of the first level and adopting a simplifying method of a thermal node, and constituting an electric driving system thermal model by establishing a system thermal model of a motor, a battery and a controller; and a third level thermal model is an entire vehicle grade thermal model in which an environmental model for the working of an electric driving part and a cooling system model for the electric driving system and an entire vehicle interface are added on the basis of an electric driving subsystem thermal model. Due to the adoption of the method, temperature variation can be calculated specific to different working conditions of a certain specified vehicle type, and the temperature value obtained by calculating can be compared with a value acquired by using a sensor to predict the variation of the temperature at a next moment.

Description

technical field [0001] The patent of the present invention relates to an algorithm of a dynamic derating control strategy based on a thermal model, which is especially suitable for hybrid electric vehicles. Background technique [0002] In the hybrid electric vehicle system, the temperature rise of the motor, battery and controller poses new challenges to the control strategy, which makes the control strategy of the hybrid electric vehicle more complicated than that of the traditional vehicle. The control strategy affects the temperature rise of the motor, battery and controller, and the temperature rise affects the life of the motor, battery and controller, and the life requirements in turn affect the control strategy; therefore, from the perspective of the system, the control strategy, life requirements There is a contradiction between fuel economy and fuel economy, and it is also a dynamic coupling relationship. To extend the life of parts, the output torque of the motor ...

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Problems solved by technology

[0005] 2. The distribution of temperature monitoring points in the current reduction strategy is limited, focusing on the temperature at the component level, without considering the thermal distribution of the entire system

[0006] 3. Some parts cannot be equipped with temperature sensors. If there is no corresponding thermal model, the temperature of the parts cannot be judged and predicted, which will affect the accuracy of reduction control

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