EV Motor Standstill Heating Using Low-Frequency AC Power
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Solution Overview
Problem
Electric vehicles face challenges in efficiently generating heat during standstill operations, particularly when conventional heat generation methods are insufficient, which can lead to inefficient battery maintenance and potential motor damage due to unintended torque generation.
Innovation Solution
A method that determines when the electric motor is at standstill, supplies it with power from a specific frequency range to generate heat without producing torque, and collects this heat using a heat pump system, ensuring efficient heat generation and distribution to critical components like the battery and cabin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the electric motor is supplied with AC voltage to generate heat, then heat generation is improved, but torque generation occurs which may damage the motor
Solution Approach 1:
The patent changes the frequency parameter of the supplied voltage to a standstill frequency range (0-2 Hz) where the motor generates heat without producing damaging torque. This parameter modification allows the motor to operate in a special regime that separates heat generation from torque production.
Solution Approach 2:
The system dynamically adjusts the frequency of supplied voltage based on motor operating conditions. During standstill operations, the frequency is modified to the standstill range, while during normal operation it returns to standard frequencies, making the heat generation capability adaptive to operational needs.
2Use of energy by moving object
If the electric motor is used for heat generation during standstill, then energy efficiency is improved, but control complexity increases
Solution Approach 1:
The electric motor is given dual functionality: it serves both as a propulsion device during vehicle operation and as a heat generation device during standstill operations. This multi-functionality improves energy efficiency by utilizing the motor for heating instead of requiring separate heating systems.
Solution Approach 2:
The motor utilizes its own electrical resistance and standstill characteristics to generate heat for the vehicle systems, essentially serving its own thermal needs during idle periods without requiring external heating equipment.
3Reliability
If conventional heat generation methods are used, then motor reliability is maintained, but energy efficiency deteriorates
Solution Approach 1:
The patent converts what would normally be wasted energy (electrical energy supplied to a stationary motor) into useful heat for the vehicle systems. Instead of simply dissipating power during standstill, the system harnesses this energy to heat the battery, cabin, or other components that require thermal management.
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 allows for effective heat management during standstill, prolonging battery life, maintaining optimal temperatures, and preventing motor damage by isolating heat generation from torque production, thus enhancing energy efficiency and vehicle readiness.
Implementation Method 1
supplying the electric motor with power, thereby generating the heat at the electric motor, the supplied power being from a frequency range
Implementation Method 2
collecting the generated heat at the electric motor by a heat pump system of the electric vehicle
Data Source
Figure 1~2
AI summary
The disclosure relates to a method for generating heat in an electric vehicle comprising an electric motor, the method comprising determining if the electric motor is at a standstill operation, upon determining that the electric motor is at a standstill operation, supplying the electric motor with a power, thereby generating the heat at the electric motor, the supplied power being from a frequency range, and collecting the generated heat at the electric motor by a heat pump system of the electric vehicle.