EV On-Board Charging Using a Bidirectional Propulsion Inverter
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Solution Overview
Problem
Existing on-board charging systems for electric vehicles are complex and costly due to the need for a controllable rectifier to convert AC power to DC power for charging.
Innovation Solution
The system utilizes an AC motor and a bidirectional inverter to convert AC power to DC power for charging, eliminating the need for a controllable rectifier by leveraging the existing AC motor and bidirectional inverter used for propulsion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a controllable rectifier is used to convert AC power to DC power for charging, then the charging function is achieved, but the system complexity and cost increase
Solution Approach 1:
The bidirectional inverter is designed to perform multiple functions: it serves as both the propulsion inverter during vehicle operation and as the charging rectifier when converting AC power to DC for battery charging. This multi-functionality eliminates the need for a separate controllable rectifier, reducing system complexity while maintaining reliable charging capability
Solution Approach 2:
The patent merges the rectifier function with the existing bidirectional inverter by using the inverter's switching devices (IGBTs and diodes) to perform both inversion and rectification operations. The same hardware components are utilized for both propulsion and charging functions, consolidating the power conversion system
2Reliability
If a controllable rectifier is used to convert AC power to DC power for charging, then the charging function is achieved, but the cost increases
Solution Approach 1:
The bidirectional inverter is designed to perform multiple functions: it serves as both the propulsion inverter during vehicle operation and as the charging rectifier when converting AC power to DC for battery charging. This multi-functionality eliminates the need for a separate controllable rectifier, reducing system complexity while maintaining reliable charging capability
Solution Approach 2:
The patent merges the rectifier function with the existing bidirectional inverter by using the inverter's switching devices (IGBTs and diodes) to perform both inversion and rectification operations. The same hardware components are utilized for both propulsion and charging functions, consolidating the power conversion system
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 simplifies the on-board charging system, reduces costs, and enhances efficiency by utilizing existing components for both propulsion and charging.
Implementation Method 1
a bidirectional inverter configured to convert AC power to DC power
Implementation Method 2
a bidirectional inverter configured to convert AC power to DC power and to convert DC power to AC power
Implementation Method 3
an AC motor connected to the bidirectional inverter
Data Source
AI summary
Embodiments include an electric vehicle having a charging port configured to receive an alternating current (AC) power, a direct current (DC) battery, and a bidirectional inverter configured to convert AC power to DC power and to convert DC power to AC power, the bidirectional inverter is selectively connected to the DC battery by propulsion switches. The electric vehicle also includes an AC motor connected to the bidirectional inverter and selectively connected to the charging port by a first charging switch, an isolated DC/DC converter motor selectively connected to the DC battery via a second charging switch and a third charging switch, and a processor configured to control the operation of the propulsion switches, the first charging switch, the second charging switch, and the third charging switch based on an operational mode of the electric vehicle.