EV Inverter Switching for Cabin and Battery Joule Heating
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Solution Overview
Problem
Electric vehicles face inefficiencies and increased costs due to the need for separate resistive heating devices and heat pumps to maintain cabin and energy storage system temperatures, particularly in cold weather, which can lead to energy loss and reduced vehicle efficacy.
Innovation Solution
Implementing a novel intermediate state for switching devices in traction inverters and onboard chargers to produce Joule heating, eliminating the need for separate resistive heating components and utilizing existing components for thermal management, thereby reducing costs and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If separate resistive heating devices and heat pumps are used to maintain cabin and energy storage system temperatures, then heating function is achieved, but vehicle cost and system complexity increase
Solution Approach 1:
The patent merges the heating function into the existing traction inverter by operating switching devices in an intermediate state between fully-on and fully-off, combining the heating capability with the motor control system and eliminating separate resistive heating devices
Solution Approach 2:
The switching devices in the traction inverter are made multi-functional by enabling them to perform both motor control (fully-on/fully-off states) and heating (intermediate state) functions, allowing a single component to serve multiple purposes
2Temperature
If separate resistive heating devices are used for heating, then heating function is provided, but vehicle weight increases
Solution Approach 1:
The heating function is merged into the traction inverter system, eliminating the need for separate resistive heating devices and their supporting components, thereby reducing overall system weight
3Use of energy by moving object
If switching devices operate in intermediate state to produce Joule heating, then heating efficiency improves, but energy loss increases
Solution Approach 1:
The patent converts the harmful energy loss (Joule heating) that occurs when switching devices operate in intermediate state into a beneficial heating function for the cabin and energy storage system, transforming waste energy into useful thermal energy
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 enables efficient and cost-effective heating of electric vehicles by repurposing existing components to generate and utilize Joule heating, reducing energy loss and enhancing overall vehicle efficiency, while maintaining reliable operation and extending component lifespan.
Implementation Method 1
The driver circuit is to operate the switching device at an intermediate state between fully-turned-off and fully-turned-on, in a heating mode to produce high levels of Joule heating
Data Source
AI summary
An ultra low cost electric vehicle heating apparatus, components thereof, and related method are herein described. A driver circuit operates a switching device at an intermediate state between fully-turned-off and fully-turned-on, in a high power dissipation heating mode, to efficiently produce heat energy for heating a passenger compartment, or energy storage system, of an electric vehicle. The driver circuit operates the switching device to have a fully-turned-off state and a fully-turned-on state in a main function mode for a traction inverter or an energy storage system charger of the electric vehicle. The driver circuit is operable to cycle the heating mode and the main function mode for combining such heating and such main function operation of the traction inverter, or the charger, without compromising the operation of the traction motor, or charger, while simultaneously eliminating many of the expensive resistive heating components in use by practitioners of the art.