EV Drive System Battery Heating via Acceleration Mode Switching
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Solution Overview
Problem
Existing drive systems for motor vehicles, particularly electric and hybrid vehicles, face challenges in efficiently warming up traction batteries at low temperatures, leading to reduced performance and increased energy loss, with conventional heating methods being inefficient and prolonging restricted operating periods.
Innovation Solution
A drive system with a control device that switches to a higher acceleration and deceleration mode when the battery temperature falls below a threshold, increasing battery currents and using additional electric motors and energy storage devices to rapidly heat the battery, while also employing a battery heater for targeted heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a battery heating device with heating elements is used to increase battery temperature, then the battery temperature can be increased, but the state of charge of the traction battery is reduced and the range of the motor vehicle is reduced
Solution Approach 1:
The traction battery serves itself by using its own stored energy to power heating elements for temperature regulation. The battery autonomously manages its thermal condition without external intervention, accepting that some energy consumption is necessary for maintaining operational temperature in cold conditions.
Solution Approach 2:
The patent converts the harmful effect of energy loss during heating into a beneficial strategy by carefully managing the heating process to prevent excessive discharge. The heating elements are controlled to provide just enough warmth to maintain battery functionality without depleting the charge needed for vehicle operation.
2Temperature
If the traction battery is used for heating through cyclical charging and discharging, then the battery temperature increases, but the heating process is slow and the operating period with restricted performance is excessively long
Solution Approach 1:
The patent employs a liquid cooling/heating circuit that circulates a thermal fluid through heat exchangers positioned among the battery cells. This hydraulic system efficiently transfers thermal energy throughout the battery pack, providing rapid and uniform temperature distribution that is much faster than electrical resistance heating or cyclical charge-discharge methods.
Solution Approach 2:
A thermal fluid acts as an intermediary medium between the heat source and the battery cells. The fluid circulates through the battery pack, absorbing or delivering heat as needed, thereby enabling efficient thermal management without direct electrical contact with the battery cells and avoiding the slow heating associated with internal resistance heating.
3Temperature
If additional heating devices are installed in the traction battery, then the battery temperature can be increased, but the energy loss is particularly high
Solution Approach 1:
The patent combines the heating function with the existing cooling system by using a dual-purpose liquid circulation circuit. The same heat exchangers and pumps used for cooling the battery during high-load operation are utilized for heating during cold conditions, eliminating the need for separate heating devices and reducing overall energy loss.
Solution Approach 2:
The thermal management system is designed to perform multiple functions: it can cool the battery during high-temperature operation and heat the battery during cold conditions. This multi-functional approach eliminates the need for dedicated single-purpose heating devices, reducing system complexity and energy consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach quickly warms up the traction battery, improves driving performance, reduces energy loss, and enhances the driving experience by compensating for cold battery performance with increased driving dynamics and targeted heating, thus improving operational reliability and efficiency.
Implementation Method 1
The battery heating device has, for example, heating elements and/or heat exchangers, which are arranged inside a battery housing of the traction battery
Implementation Method 2
a traction battery (4) for supplying the first electric motor (3) with electrical energy
Implementation Method 3
a first electric motor (3) for driving the motor vehicle (2)
Data Source
Figure 1~2
AI summary
The present invention relates to a drive system (1) for a motor vehicle (2), comprising a first electric motor (3) for driving the motor vehicle (2), a traction battery (4) for supplying the first electric motor (3) with electrical energy, a control device (5) for controlling the first electric motor (3) and the traction battery (4), and a temperature sensor (6) coupled to the control device (5) for data communication and for determining the actual battery temperature of the traction battery (4), wherein the control device (5) for operating the drive system (1) has several operating modes selectable by a driver of the motor vehicle (2), wherein the operating modes have a first operating mode and a second operating mode, the second operating mode having a steeper acceleration and/or deceleration behavior compared to the first operating mode.The control device (5) is designed and configured to switch to the second operating mode in a first operating state of the drive system (1) in which the first operating mode is selected and the determined actual battery temperature is lower than a predetermined lower battery temperature threshold. Furthermore, the invention relates to a motor vehicle (2) with a drive system (1) according to the invention.