Vehicle Battery Heating via Pulsed Motor Current Without Torque Change
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle battery heating systems are ineffective at low temperatures, especially when the vehicle is in motion, as they either require the vehicle to be stationary or result in unwanted torque formation during driving.
Innovation Solution
A procedure that utilizes a pulse inverter to generate a pulsating heating current between the vehicle battery and electric machine by varying the drive current based on energy stored in the magnetic field, allowing for continuous heating without changing the torque, using a D/Q transformation and energy control to manage the pulsating current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating elements or heating devices are arranged on the vehicle battery to provide heating, then the battery can be heated, but the heating is ineffective due to heat losses when heating the cell casing, resulting in an overall insufficient heating effect
Solution Approach 1:
The invention extracts the heating function from external heating elements and transfers it to the electric motor itself by utilizing the energy stored in its magnetic field. This eliminates the need for separate heating devices and reduces heat losses by generating heat directly within the battery through controlled current pulsation in the motor circuit.
Solution Approach 2:
The electric motor serves a dual function: propulsion and heating. By utilizing the motor's magnetic field energy and circuit resistance, the system generates heating current internally without requiring external heating elements, thereby reducing energy losses and improving heating efficiency.
2Temperature
If the drive current is varied to generate heating current, then the battery can be heated during driving, but the torque may change which affects vehicle operation
Solution Approach 1:
The invention applies periodic pulsating current to the electric motor circuit at frequencies that do not affect the motor's torque production. By utilizing the motor's inductance and back-EMF characteristics, the system superimposes high-frequency current pulses on the drive current, generating heat through resistive losses while maintaining the average torque required for vehicle propulsion.
Solution Approach 2:
The control system dynamically adjusts the drive current parameters based on real-time operating conditions, varying the current pulse amplitude and frequency to optimize heating effectiveness while maintaining constant torque output. The system continuously monitors motor parameters and adapts the heating current superposition to preserve torque stability during battery heating.
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
Enables effective battery heating during vehicle operation without generating unwanted torque, thereby improving heating efficiency and extending the usage of the heating function beyond stationary conditions.
Implementation Method 1
the stored energy in the magnetic field is varied, thus generating a pulsating heating current between the battery and the electric motor
Implementation Method 2
drive current is varied depending on a predetermined torque and energy stored in a magnetic field of the electric motor such that the stored energy in the magnetic field is varied
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for heating a vehicle battery (51) of a vehicle (50) with an electric motor (52), wherein, during a journey of the vehicle (50), the drive current (i) is selected by the pulse inverter (2) from a drive current provided by the pulse inverter (2). A driving-condition-independent battery heating method is provided by selecting the drive current (i) as a function of a predetermined torque (T) and by specifying an energy (E) stored in a magnetic field of the electric motor such that the stored energy (E) in the magnetic field is varied and thus a pulsating heating current is generated between the vehicle battery (51) and the electric motor (52) without changing the torque (T).