Electric Vehicle Motor Driver Periodic Energy Recovery
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Solution Overview
Problem
Conventional electric vehicles do not efficiently perform energy recovery operations outside specific conditions like downhill slopes, resulting in low battery charging efficiency.
Innovation Solution
An electric vehicle system that includes a rechargeable battery, a motor, a motor driver, and a controller, which automatically performs energy recovery by switching between motor driving and charging modes during idle periods between periodically supplied motor driving signals, using transistors and recovery diodes to manage current flow and maintain constant rotational frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If energy recovery operation is performed only under specific conditions (downhill, brake applied), then the system complexity is reduced, but battery charging efficiency deteriorates
Solution Approach 1:
The motor driver periodically switches between motor driving mode and energy recovery mode based on timing signals from the controller. During idle periods between periodic motor driving signals, the system automatically performs energy recovery operations, converting the motor into a generator to charge the battery. This periodic switching enables continuous energy recovery without requiring complex condition detection.
2Loss of energy
If motor driving signal supply is stopped to perform energy recovery operation, then energy recovery is achieved, but motor speed control deteriorates
Solution Approach 1:
The controller generates periodic motor driving signals that create regular idle periods. During these predetermined idle periods, the motor driving signal is intentionally stopped to enable energy recovery while the motor maintains constant rotational frequency through the periodic signal pattern. This ensures both energy recovery and speed control are achieved through timed periodic operation.
Solution Approach 2:
The controller pre-establishes the timing and duration of idle periods in the periodic motor driving signal pattern. By planning when energy recovery operations will occur in advance through the periodic signal structure, the system ensures that motor speed is maintained at constant rotational frequency while energy recovery is performed during predetermined intervals.
3Productivity
If energy recovery operation is performed continuously, then battery charging efficiency is improved, but motor driving performance deteriorates
Solution Approach 1:
The system alternates between motor driving periods and energy recovery periods through periodic switching controlled by the controller. During supply periods, the motor receives driving current for vehicle propulsion; during idle periods, the motor generates electricity for battery charging. This periodic alternation ensures both motor driving performance and battery charging efficiency are maintained without continuous operation in either mode.
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 enhances battery charging efficiency by automatically recovering energy during idle periods, maintaining constant motor speed, and improving overall battery charging performance.
Implementation Method 1
perform charging of the battery using recovery charging current generated by the motor during a plurality of idle periods
Implementation Method 2
The motor driver may include a plurality of transistors, and a plurality of recovery diodes, and ones of the recovery diodes may be connected in parallel to respective ones of transistors
Implementation Method 3
The motor driver may include a plurality of transistors, and a plurality of recovery diodes, and ones of the recovery diodes may be connected in parallel to respective ones of transistors
Data Source
AI summary
An electric vehicle includes a rechargeable battery, a wheel, a motor coupled to the wheel, a motor driver coupled to the motor and coupled to the battery, the motor driver being configured to drive the motor by discharging the battery in response to a motor driving signal during each of a plurality of supply periods and perform charging of the battery using recovery charging current generated by the motor during a plurality of idle periods, each of the idle periods being between two adjacent ones of the supply periods, and a controller coupled to the motor driver, the controller being configured to supply the motor driving signal to the motor driver during each of the supply periods, and control the motor driver to charge the battery during each of the idle periods.