Electric Drive Motor Control for Simultaneous Battery Warm-up and Vehicle Propulsion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery warm-up technologies for electric vehicles and hybrid vehicles are inefficient, as they either consume energy without generating torque or require exclusive use of internal combustion engines, failing to effectively warm batteries during cold starts and neglect environmental considerations.
Innovation Solution
A control device for electric drive motors that adjusts q-axis and d-axis currents based on battery temperature and drive torque requirements, allowing simultaneous battery warm-up and vehicle operation, optimizing energy use and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If only d-axis current is fed through the electric drive motor for battery warm-up, then the battery can be warmed up by heat generation, but the vehicle cannot be driven simultaneously and the internal combustion engine must be used for warm-up in hybrid vehicles
Solution Approach 1:
The patent combines battery warm-up function and vehicle driving function into a single operational mode by simultaneously applying d-axis current (for heat generation) and q-axis current (for torque production). This merging allows the electric drive motor to perform both warming up the battery and propelling the vehicle at the same time, eliminating the need to choose between these functions.
Solution Approach 2:
The electric drive motor is made multi-functional by enabling it to simultaneously provide thermal energy (through d-axis current) and mechanical work (through q-axis current). This universality allows the same motor to serve dual purposes: warming up the battery and driving the vehicle, thereby eliminating the need for separate systems or operational modes.
2Temperature
If internal combustion engine is used for vehicle warm-up during battery warm-up operation, then both warm-up operations can be performed simultaneously, but environmental considerations such as emissions reduction are compromised
Solution Approach 1:
The patent extracts the internal combustion engine from the warm-up process and replaces it entirely with electric drive motor-based warm-up. By removing the combustion engine's involvement in battery warm-up operations, the harmful emissions associated with combustion are eliminated, while the battery is still effectively warmed up through electrical current.
Solution Approach 2:
The patent converts what would traditionally be a harmful situation (using combustion engine causing emissions) into a beneficial one (using electric motor providing zero emissions). By utilizing the electric drive motor's ability to generate heat through electrical resistance and electromagnetic losses, the system achieves warm-up without any harmful emissions, turning a potential environmental problem into an environmental solution.
3Temperature
If d-axis current is used for battery warm-up in stopped vehicle, then battery warm-up can be achieved, but no vehicle motion is produced
Solution Approach 1:
The patent merges the stationary warm-up function and motion function into a unified operational capability. By allowing simultaneous application of d-axis and q-axis currents, the system can transition from pure warm-up (d-axis only, vehicle stopped) to combined operation (both currents, vehicle moving), thereby achieving both temperature increase and vehicle propulsion through the same motor system.
4Speed
If q-axis current is used for vehicle driving, then vehicle motion is achieved, but battery warm-up cannot be simultaneously performed
Solution Approach 1:
The patent combines the vehicle driving function (q-axis current producing torque) and battery warm-up function (d-axis current producing heat) into a single simultaneous operation. By allowing both current components to exist together in the motor control system, the vehicle can be propelled while the battery is warmed up at the same time, eliminating the need to prioritize one function over the other.
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 solution speeds up battery warm-up in both electric and hybrid vehicles, enabling efficient operation regardless of the vehicle's mode, reducing energy consumption, and promoting environmental sustainability by utilizing electric drive motors effectively.
Implementation Method 1
feed a d-axis current for vector control through the electric drive motor... allow the battery to discharge for heat generation purposes
Implementation Method 2
vector control of an electric drive motor-control device... d-axis current is a current flowing in a direction of strengthening a magnetic flux of a permanent magnet of a motor rotor
Data Source
AI summary
A controller for vector-controlled motor of vehicle judges whether a battery needs to be warmed up in accordance with an output of a battery temperature sensor, and when the battery needs to be warmed up, in situation (i) where the vehicle is stopped, sets a q-axis current value of the motor at zero, or when a brake is released from the situation (i), sets a q-axis current at a value corresponding to a drive torque for a vehicle creep operation, and sets a d-axis current at a value for battery warm-up. When the battery needs to be warmed up in situation (ii) where the vehicle is running, the controller sets a q-axis current at a value corresponding to a drive torque of vehicle running and sets a d-axis current at a value for the battery warm-up in relation to the q-axis current value.