AC Rotary Machine Current Control for Battery Heating
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Solution Overview
Problem
Existing temperature rise control devices for secondary batteries in AC rotary machines suffer from uneven current distribution across phases, limiting the ability to achieve a large current flow for short durations and neglecting the efficiency of motor temperature rise, which can lead to biased heat generation and reduced performance.
Innovation Solution
An AC rotary machine apparatus with a power conversion device that generates three-phase alternating currents with a 180-degree phase difference between U-phase, V-phase, and W-phase coils and X-phase, Y-phase, Z-phase coils, allowing for even current distribution and controlled temperature rise without external circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the motor is driven without rotation using conventional three-phase current control, then the secondary battery can self-generate heat, but the current distribution becomes biased toward specific phases, preventing large current flow for short durations
Solution Approach 1:
The patent divides the three-phase coil system into two independent three-phase coil sets (first three-phase coils and second three-phase coils). By controlling these separate sets with 180-degree phase differences, the system achieves more uniform current distribution across all phases while preventing bias toward specific phases, thereby enabling large current flow for short durations while maintaining reliable heat generation.
2Temperature
If conventional temperature rise control is implemented, then the secondary battery temperature increases, but the motor temperature efficiency is not considered, leading to suboptimal overall system performance
Solution Approach 1:
The patent implements a multi-functional control system that simultaneously manages both secondary battery temperature and motor temperature. The power conversion device and control unit work together to generate controlled currents that achieve temperature rise in the secondary battery while also efficiently heating the motor, thereby improving overall system productivity without requiring separate control systems.
3Temperature
If external temperature control circuits are added to achieve temperature rise, then temperature management capability improves, but device complexity and cost increase
Solution Approach 1:
The power conversion device is designed to perform multiple functions: it converts DC from the secondary battery to AC for motor drive control, and simultaneously serves as a temperature control device by generating controlled three-phase currents with 180-degree phase differences. This eliminates the need for external temperature control circuits, reducing device complexity and cost while maintaining effective temperature management capability.
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 large current flow for short durations across all phases, efficiently heating both the secondary battery and motor, eliminating the need for external temperature control circuits and providing an inexpensive solution for temperature management.
Implementation Method 1
a power conversion device which converts direct current generated by the secondary battery to alternating currents
Implementation Method 2
first three-phase coils and second three-phase coils for generating rotating magnetic fields in the rotor
Implementation Method 3
a magneto rotor and has first three-phase coils and second three-phase coils for generating rotating magnetic fields in the rotor
Implementation Method 4
the secondary battery self-generates heat by being charged/discharged, causing the secondary battery to rise in temperature
Data Source
AI summary
With the object of preventing deterioration due to the temperature when charging a secondary battery, a configuration is such that currents are controlled so as to be caused to flow equally through the respective phases of three-phase coils of a second group which configure an AC rotary machine body, whereby a large current is caused to flow for a short time, causing the secondary battery to rise in temperature, even when the AC rotary machine body is in a state of rest.