AC Motor Open-Circuit Fault Control With Rotor-Angle Current Optimization

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Solution Overview

Problem

Existing fault-tolerant control methods for open-circuit faults in three-phase alternating current motors require hardware modifications, increasing costs and system complexity, and often suffer from limited speed range, complex control strategies, low control accuracy, and reduced torque output capability.

Innovation Solution

A fault-tolerant control method and apparatus that constructs an optimization model considering quadrature-axis and direct-axis currents with the motor rotor electrical angle, determining phase current references using cost and limiting equations, without modifying the hardware circuit, to manage open-circuit faults in alternating current motors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hardware circuit modifications are made to achieve fault-tolerant control, then reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvefault-tolerant control capabilityVSAvoidhardware circuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces hardware circuit modifications with a software-based control method. By using an optimization model with cost equations and limiting conditions to determine phase current references, the system achieves fault-tolerant control without any physical circuit changes, thereby maintaining reliability while reducing device complexity and cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes control parameters (phase current references) dynamically based on fault detection and optimization calculations. By adjusting electrical parameters through software rather than modifying hardware circuits, the system achieves adaptability to faults while keeping the hardware structure simple and cost-effective.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If existing fault-tolerant control methods are used without hardware modification, then device complexity is reduced, but torque output capability and control accuracy deteriorate

Engineering Contradiction:
Improvehardware circuit structureVSAvoidtorque output capability
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent implements dynamic adjustment of phase current references through an optimization model that continuously calculates optimal current values based on limiting conditions. This dynamic control approach maintains torque output capability without hardware modifications by adapting control parameters in real-time according to system constraints.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses feedback from fault detection and system state monitoring to adjust phase current references through the optimization model. By incorporating limiting conditions and cost equations that respond to actual system performance, the control system maintains high torque output capability while using only software-based fault tolerance.

Inventive Principle:
Principle #23Feedback

3Reliability

If phase current references are adjusted to achieve fault-tolerant control, then reliability is improved, but copper consumption and efficiency worsen due to increased current peak values

Engineering Contradiction:
Improvefault-tolerant operationVSAvoidcopper consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent optimizes phase current reference parameters through an optimization model that explicitly considers limiting conditions. By carefully adjusting current parameters to satisfy constraints while maintaining torque requirements, the system achieves fault-tolerant operation with minimized current peak values, thereby reducing copper consumption and maintaining efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4580040A1Fault-tolerant control method and apparatus for open-circuit faults of alternating-current motor, and storage medium
Publication Date: 2025.07.02 XPT EDS (HEFEI) CO LTD
  • EP4580040A1 patent drawingFigure 1~2
  • EP4580040A1 patent drawingFigure 3~4
  • EP4580040A1 patent drawing

AI summary

The present disclosure relates to the field of motor control, and in particular to a fault-tolerant control method and apparatus for an open-circuit fault in an alternating current motor, a computer device and a computer storage medium. The method comprises: A. constructing a fault-tolerant control optimization model, in consideration of a condition that quadrature-axis current and direct-axis current of a motor change along with a motor rotor electrical angle, wherein the fault-tolerant control optimization model comprises a cost equation generated based on a motor torque equation and a limiting condition consisting of one or more of a fault phase current equation, a motor phase current limiting equation, and a motor phase voltage limiting equation; and B. determining a phase current reference value at a current motor rotor electrical angle by using the fault-tolerant control optimization model.