Drive Motor Controller Using Stator Heat for Battery Warming

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Solution Overview

Problem

Electric vehicles face challenges in maintaining optimal battery temperature in low-temperature environments, leading to reduced battery capacity and efficiency, as conventional heating systems require additional apparatuses and incur high costs.

Innovation Solution

A controller for the drive motor that utilizes heat generated by the motor to warm the power battery through a cooling loop, adjusting output currents based on battery temperature and voltage to increase heating efficiency without additional heating apparatuses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a PTC heating apparatus is used to heat the power battery, then the battery temperature can be maintained in optimal range, but the device complexity and cost increase

Engineering Contradiction:
Improvepower battery temperatureVSAvoidheating apparatus complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The drive motor generates heat during operation that is normally wasted, but this heat is now utilized to heat the power battery when needed. The system serves itself by using its own operational byproduct (heat) to meet its heating requirements, eliminating the need for external heating apparatus.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The heat generated by the drive motor during operation is converted from a wasted byproduct into a useful resource for heating the power battery. This transforms what was previously considered waste heat into a beneficial heating source, eliminating the need for additional heating equipment.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Temperature

If output current is increased to generate more heat in the three-phase stator winding, then the heating rate of the power battery increases, but the energy loss increases

Engineering Contradiction:
Improvepower battery temperatureVSAvoidenergy loss
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The energy loss in the form of heat from the three-phase stator winding is converted into a useful resource for heating the power battery. Instead of dissipating this heat into the environment, the system captures and utilizes it to maintain battery temperature, transforming energy loss into energy gain.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The three-phase stator winding serves dual functions: it generates torque to drive the vehicle and simultaneously generates heat to warm the power battery. This multi-functionality allows the same component to perform both propulsion and heating tasks, improving overall system efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively heats the power battery using the drive motor's generated heat, enhancing battery performance in low temperatures while reducing costs by eliminating the need for additional heating systems.

Implementation Method 1

control the output current of the inverter circuit to increase heat generated by the three-phase stator winding of the drive motor

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The three-phase stator winding and a rotor winding may perform heat exchange with the power battery through a cooling loop

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4321375A1Controller for drive motor and related device thereof
Publication Date: 2024.02.14 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4321375A1 patent drawingFigure 1~2
  • EP4321375A1 patent drawingFigure 3
  • EP4321375A1 patent drawingFigure 4

AI summary

This application provides a controller for a drive motor and a related device thereof. The drive motor performs heat exchange with a power battery through a cooling loop. The drive motor includes a three-phase stator winding. The power battery supplies power to the three-phase stator winding through an inverter circuit. In response to that a temperature of the power battery is greater than or equal to a preset battery temperature, the controller controls an output current of the inverter circuit, so that the drive motor outputs torque to drive a wheel. In response to that a temperature of the power battery is less than a preset battery temperature, the controller adjusts an output current of the inverter circuit based on a result of comparison between a voltage of the power battery and a preset battery voltage, to control the output current of the inverter circuit to increase heat generated by the three-phase stator winding of the drive motor. According to this application, the power battery may be heated by using the heat generated by the drive motor, thereby reducing costs.