Traction Battery Heating Circuit Using Inverter Phase Switching
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Solution Overview
Problem
Traction batteries experience significant discharge capacity decay and limited charge capability in low temperature environments, particularly affecting vehicles with six-phase motors, leading to poor user experience.
Innovation Solution
A traction battery heating circuit and control method that alternately switches charge and discharge loops through a control module, utilizing a power supply, inverter, and driving module to convert electrical energy into thermal energy for battery heating, with phase leg control to minimize noise and overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traction batteries are used in low temperature environments, then the batteries can operate in cold conditions, but discharge capacity severely decays and charge capability is limited
Solution Approach 1:
The heating circuit activates before the battery is fully charged or discharged in low temperature conditions, pre-heating the battery to maintain optimal operating temperature. This preliminary thermal preparation ensures the battery maintains sufficient charge and discharge capabilities throughout the operational cycle, resolving the contradiction between cold environment adaptability and productivity.
2Power
If six-phase motors are used to provide more power, then motor performance is improved, but charge and discharge capability requirements increase which exposes battery limitations in cold conditions
Solution Approach 1:
The heating circuit acts as an intermediary system between the six-phase motor and the traction battery. It maintains the battery at optimal temperature, enabling the battery to support the high power demands of the six-phase motor even in low temperature environments, thus resolving the contradiction between motor performance and battery capability.
3Productivity
If battery heating is implemented in low temperature environments, then charge and discharge capability is maintained, but additional heating energy is required
Solution Approach 1:
The heating circuit utilizes the battery's own internal resistance to generate heat through controlled charge and discharge cycles, rather than requiring an external heating source. This self-heating mechanism maintains battery temperature and capability while minimizing additional energy consumption from external systems.
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
Effectively heats traction batteries to normal operating temperature, enhancing their functionality in low temperatures and improving user experience by maintaining charge and discharge capability.
Implementation Method 1
The battery group has an internal resistance, consuming part of the current to convert electric energy into thermal energy that heats the battery group of the power supply module
Data Source
AI summary
A traction battery heating circuit, system, and control method, and an electric device are provided. In some embodiments, the traction battery heating circuit includes: a power supply module, including at least one battery group; an inverter module, connected to the power supply module and including an M-phase leg circuit, where the leg circuit is connected in parallel to the battery group, and M is an even multiple of three; a driving module, including a motor having M windings, where the M windings are respectively connected to M phase legs of the leg circuit in one-to-one correspondence; and a control module, connected to the leg circuit, configured to control upper legs of at least three phase legs in the leg circuit and lower legs of the same number of phase legs in remaining legs to be turned on.