Three-Phase Motor Control for Zero-Sequence Torque Suppression
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Solution Overview
Problem
Three-phase motors in vehicles experience unintended torque generation due to zero phase sequence component currents, which reduces power transmission efficiency and causes unintentional vehicle movement during battery charging.
Innovation Solution
An apparatus and method that determine a second torque value to suppress the first torque value caused by zero phase sequence component currents, involving a torque determination device, a control amount determination device, and a controller to adjust the voltage control amount, using a d-q axis framework and proportional integral (PI) control scheme, to generate a driving voltage for the three-phase motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If current flows through the three-phase motor to charge the battery, then battery charging function is improved, but unintended torque is generated causing vehicle movement and reducing power transmission efficiency
Solution Approach 1:
The patent converts the harmful zero phase sequence component current into a beneficial control signal. By detecting the zero phase sequence component in the motor current, the system generates a compensating current that cancels out the unintended torque while maintaining the battery charging function. This transforms the harmful effect into a useful control mechanism.
Solution Approach 2:
The system applies preliminary anti-action by calculating and applying a compensating torque in advance to counteract the unintended torque before it causes vehicle movement. The controller continuously monitors the motor current, detects zero phase sequence components, and generates opposing torque commands to prevent the harmful effect from manifesting.
2Use of energy by moving object
If conventional motor control is used during battery charging, then charging current flows through the motor, but torque is induced reducing power transmission efficiency
Solution Approach 1:
The patent implements feedback control by continuously monitoring the three-phase current flowing through the motor, detecting zero phase sequence components, and adjusting the compensating current accordingly. This closed-loop feedback mechanism ensures that the compensating torque precisely counteracts the unintended torque, maintaining optimal power transmission efficiency throughout the charging process.
Data Source
AI summary
An apparatus and method for suppressing torque generation of a three-phase motor, includes a torque determination device that determines a second torque value for suppressing a first torque value due to a zero phase sequence component current of the three-phase motor, a control amount determination device that determines a voltage control amount for generating the determined second torque value, and a controller that is configured to control the three-phase motor according to the determined voltage control amount.