Electric Vehicle Miswiring Detection via Torque Estimation
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Solution Overview
Problem
Existing electric vehicle control devices fail to detect miswiring in induction motors, leading to continuous reactive current flow, potential malfunction, and deterioration, especially when phase sequences are miswired, as they lack a simple method for induction motor miswiring detection.
Innovation Solution
An electric vehicle control device comprising drive control systems with an induction motor, inverter, current detector, speed detector, and a controller that includes a miswiring detector to calculate torque estimation values and detect miswiring based on motor currents and voltage command values, allowing for the identification of miswired induction motors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If phase sequence of induction motor is miswired, then the miswired induction motor is driven by output torque of properly wired induction motor and rotational speeds are adjustable, but reactive current continues flowing through the induction motor causing malfunction or deterioration
Solution Approach 1:
The miswiring detection function performs preliminary detection before the induction motor suffers damage from continuous reactive current flow. By calculating torque estimation values and comparing them with actual torque during normal operation, the system identifies miswiring conditions early, allowing corrective action before malfunction or deterioration occurs.
Solution Approach 2:
The system continuously monitors the relationship between torque command values and torque estimation values during motor operation. When a discrepancy exceeds a predetermined threshold, the system provides feedback indicating miswiring, enabling real-time detection while the motor is running at adjustable speeds.
2Measurement precision
If miswiring detection for induction motor is implemented, then miswired induction motor can be detected, but detection method must account for slip concept unlike synchronous motor
Solution Approach 1:
The miswiring detection utilizes existing control parameters (torque command values and torque estimation values) that are already calculated during normal vector control operation. The system serves itself by using its own operational data for detection purposes, eliminating the need for separate detection hardware or complex additional measurements.
Solution Approach 2:
The detection method monitors changes in the relationship between torque command values and torque estimation values. When miswiring occurs, the torque estimation value deviates from the command value beyond a predetermined threshold, providing a simple parameter-based detection criterion that accounts for induction motor slip characteristics.
Data Source
AI summary
An electric vehicle control device includes a plurality of drive control systems that controls travelling of an electric vehicle. Each of the drive control systems includes an induction motor, an inverter that drives the induction motor, and a controller that controls the inverter. Each of the controllers of the plurality of drive control systems includes a miswiring detector that calculates a torque estimation value on a basis of motor currents and voltage command values and detects miswiring between the induction motor and the inverter on a basis of the calculated torque estimation value and the torque command value.