Vehicle Motor Control to Reduce Circulating Current in Energy Storage
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Solution Overview
Problem
Circulating currents in energy storage devices of vehicles lead to power loss, as existing technologies do not effectively address this issue.
Innovation Solution
A vehicle configuration that includes a motor, energy storage device, drive device, and processor to control the motor and drive device to reduce power generation and increase load consumption when a circulating current occurs, thereby decreasing the circulating current and associated power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the motor generates electric power to charge the energy storage device, then the energy storage device stores more electric power, but circulating current increases causing power loss
Solution Approach 1:
The control device monitors the state of charge and voltage of the energy storage device, and adjusts the motor's power generation accordingly. When the energy storage device reaches a certain charge level or voltage threshold, the control device reduces or stops regenerative braking to prevent circulating current and power loss.
Solution Approach 2:
The system dynamically changes the operating parameters of the motor (power generation level) based on the state of the energy storage device. By adjusting the amount of electric power generated during regenerative braking, the system optimizes charging efficiency while preventing circulating current conditions that cause power loss.
2Quantity of substance
If the energy storage device voltage is high, then more electric power can be stored, but circulating current increases causing power loss
Solution Approach 1:
The control device continuously monitors the voltage of the energy storage device and uses feedback control to regulate the motor's power generation. When voltage reaches a threshold that may cause circulating current, the system adjusts the charging rate to maintain optimal voltage levels and prevent power loss.
Solution Approach 2:
The system dynamically adjusts the power generation level based on real-time voltage conditions. Rather than operating at fixed parameters, the motor's regenerative braking capability is modulated according to the energy storage device's voltage state, allowing the system to adapt to changing conditions and avoid circulating current.
3Power
If regenerative braking is maximized, then electric power generation increases, but circulating current and power loss increase
Solution Approach 1:
The system optimizes the power generation parameter by adjusting regenerative braking levels based on energy storage device state. Instead of maximizing power generation at all times, the control device modulates the regenerative braking torque to achieve optimal power recovery while preventing circulating current conditions.
Data Source
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AI summary
A vehicle (100) includes a motor (MG) configured to generate electric power, an energy storage device (B1) configured to store the electric power generated by the motor (MG), a drive device (18) electrically connected to the energy storage device (B1) and the motor (MG) and configured to drive the motor (MG), and a processor configured to control the drive device (18) to cause the motor (MG) to generate less power when a circulating current occurs than when there is no circulating current. The circulating current is a current that does not flow into the drive device but circulates in the energy storage device (B1) or that circulates between inside and outside of the energy storage device (B1).