PMSM Stator Fault Detection via Negative Sequence Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for detecting inter-turn short circuit faults in parallel coil type permanent magnet motors are inefficient, often requiring extensive experimental data and resulting in significant errors and deviations, making it difficult to accurately identify fault phases and quantities.
Innovation Solution
A method and system that utilize a mathematical model to detect stator coil winding inter-turn short circuit faults by analyzing electrical variations and negative sequence components, allowing for accurate identification of faulty phases and fault quantities without the need for extensive testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional fault detection methods using predetermined reference levels are used, then fault detection can be performed, but considerable deviation and error are generated requiring large amounts of experimental data
Solution Approach 1:
The patent replaces conventional experimental trial-and-error methods with a mathematical model-based detection system. The system uses voltage and current equations to calculate negative sequence components, substituting physical experimentation with computational analysis to achieve accurate fault detection without requiring extensive experimental data
Solution Approach 2:
The patent creates a virtual model of the motor system using mathematical equations that replicate the electrical behavior. By copying the motor's voltage and current characteristics into a mathematical framework, the system can predict and detect faults through calculation rather than physical experimentation
2Reliability
If conventional fault detection methods are used, then fault detection can be performed, but the cause of motor fault cannot be correctly detected and motor control becomes difficult
Solution Approach 1:
The patent segments the fault detection process into distinct computational steps: calculating negative sequence voltage components, calculating negative sequence current components, comparing these components to determine fault conditions, and identifying specific fault phases. This segmentation transforms a complex control problem into manageable calculation steps that improve reliability without overwhelming system complexity
Solution Approach 2:
The system continuously monitors voltage and current, calculates negative sequence components in real-time, and uses this feedback to identify fault conditions. The feedback mechanism compares calculated values against threshold criteria, enabling reliable fault detection and control adjustments based on ongoing system state evaluation
3Measurement precision
If extensive experimental data is collected to reduce deviation and error, then measurement precision can be improved, but efforts and expenses increase
Solution Approach 1:
The patent establishes mathematical models and detection criteria in advance, before actual fault detection is needed. The negative sequence component calculation methods and fault determination thresholds are pre-configured based on theoretical analysis, eliminating the need for time-consuming experimental data collection while maintaining high detection precision
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to a permanent magnet motor. Disclosed are a method and system for detecting a fault of a parallel coil type permanent magnet motor. This method includes driving a parallel coil type motor on the basis of a pre-defined current reference value, detecting a phase current vector of the motor, and calculating a current compensation value for removing a negative sequence component of the motor on the basis of the phase current vector. The method further includes providing the current compensation value to a negative sequence current controller, calculating a faulty phase and a degree of fault of the parallel coil type motor by using the output of the negative sequence current controller and a fault model considering both flux variation in a specific slot of a specific phase of the parallel coil type motor and induced flux variations in other slots of the same phase when the parallel coil type motor has a fault, and applying a current reference value to which the calculated faulty phase and degree of fault have been applied.