Electric Motor Heating Using D-Axis AC and Coolant Heat Exchange
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Solution Overview
Problem
Existing battery heating methods for electric vehicles, such as using direct current to heat the motor stator winding, result in low heating power and slow heating speed, uneven heating, and cannot heat the battery during operation.
Innovation Solution
Inputting a direct-axis alternating current into the motor winding to generate heat through eddy current and magnetic hysteresis losses in the rotor and stator, combined with a heat exchange system using insulation coolant channels for efficient heat distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If direct current is used to heat the motor stator winding, then the battery can be heated, but the heating power is small and heating speed is slow
Solution Approach 1:
The patent changes the electrical parameter from direct current to alternating current with direct-axis component, which transforms the heating mechanism from simple resistive heating to eddy current and magnetic hysteresis heating, significantly increasing heating power and speed
Solution Approach 2:
The patent replaces the traditional resistive heating mechanism with electromagnetic induction heating mechanism, utilizing eddy currents and magnetic hysteresis in the rotor and stator to generate heat, thereby achieving higher heating efficiency without additional heating equipment
2Temperature
If direct current is used to heat the motor stator winding, then the battery can be heated, but the heating is uneven
Solution Approach 1:
The patent introduces multiple heat generation sources segmented throughout the motor structure (rotor, stator, and winding), each contributing to overall heating, which distributes heat more uniformly across the battery rather than concentrating it in one location
Solution Approach 2:
The patent combines multiple heating mechanisms (eddy current heating in rotor and stator, magnetic hysteresis heating, and copper loss heating in winding) to work simultaneously, creating a distributed and uniform heating field that evenly heats the battery
3Temperature
If direct current is used to heat the motor stator winding, then the battery can be heated, but the motor cannot operate during heating
Solution Approach 1:
The patent makes the motor capable of dual function: it can operate as a motor during normal driving and as a heater during low-temperature conditions. By using alternating current with direct-axis component, the motor generates heat through electromagnetic losses while still maintaining the ability to produce rotational motion, allowing both heating and motor operation simultaneously
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
Enhances heating power and speed, allows battery heating during vehicle operation, and avoids uneven heating without additional equipment costs.
Implementation Method 1
the rotating shaft and the rotor iron core of the rotor of the motor, and the stator generate heat due to an eddy current loss and a magnetic hysteresis loss
Implementation Method 2
the rotating shaft and the rotor iron core of the rotor of the motor, and the stator generate heat due to an eddy current loss and a magnetic hysteresis loss
Implementation Method 3
the permanent magnet of the rotor generates heat due to an eddy current loss
Implementation Method 4
the winding generates heat due to a copper loss
Implementation Method 5
An insulation coolant flowing in the second hole channel performs heat exchange with the rotating shaft... An insulation coolant flowing in the fourth hole channel is used to perform heat exchange with the stator
Data Source
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AI summary
This application discloses a motor, a motor controller, a heat exchange system, and a control method, and relates to the motor field and is used to improve motor heating efficiency. The motor includes a housing, a stator mounted inside the housing, a rotor connected to the housing through a bearing, a winding wound on the stator, and a liquid inlet hole and a liquid outlet hole that are connected to a cavity in the housing. The liquid inlet hole is used for inflow of an insulation coolant, and the liquid outlet hole is used for outflow of an insulation coolant. The rotor includes a rotating shaft, a rotor iron core mounted around the rotating shaft, and a permanent magnet mounted on the rotor iron core. A first hole channel connected to the cavity is disposed on the rotor iron core. The winding is configured to input a direct-axis alternating current.