Fault Diagnosis Method of Six-Phase Permanent Magnet Synchronous Motor Based on Vector Space Decoupling

Abstract

Compared with the three-phase motor, the six-phase motor has lower torque ripple and higher fault tolerance performance, which makes it widely used in aviation, ships, industrial manufacturing, and other application fields. However, the probability of failure of the polyphase motor system increases with the increase in the number of phases. In order to deal with the open phase fault and power switch fault of the six-phase inverter, a fault diagnosis method for the six-phase inverter based on vector space decoupling (VSD) is proposed. The open phase fault index is first determined according to the VSD decoupling inverse transform and the current constraints. The fault index is then optimized from the perspective of preventing misdiagnosis and improving reliability, and the open phase fault can be diagnosed in one fundamental cycle. In addition, the current trajectory of harmonic plane after switch fault is analyzed, and the back propagation (BP) neural network is used to identify the harmonic plane current trajectory of different types of switch fault. Finally, the correctness and feasibility of the proposed fault diagnosis method are verified by simulations and experiments. The obtained results demonstrate that the proposed method can quickly and accurately locate the open phase fault and switch fault without additional hardware. The proposed method is simple, efficient, and robust.

Fault Diagnosis of Ship Ballast Water System Based on Support Vector Machine Optimized by Improved Sparrow Search Algorithm

“…Sparrows with better fitness in SSA are called discoverers, which are in charge of searching for food and guiding the whole population. In (2), n is the current iteration count, 𝑀 is the maximum iteration count, 𝑋 𝑖,𝑗 𝑛 is the position of the 𝑖-th sparrow in the 𝑗-th dimension in the 𝑛-th iteration, 𝛼 ∈ (0,1] is a random number, 𝑄 ∈ [0,1] is a random number subject to normal distribution, 𝐿 is a 1 × 𝑑𝑖𝑚 matrix, and all elements are 1. 𝑅 2 ∈ [0,1] is a random number, 𝑆𝑇 ∈ [0.5,1.0] is a safety threshold, and the generated random number 𝑅 2 will be compared with the safety threshold 𝑆𝑇 to determine whether the sparrow is in a safe state.…”

“…With the development of intelligent ships, algorithms such as Convolutional neural network (CNN) [1], Backpropagation neural network (BPNN) [2], Deep learning algorithm [3], Artificial neural network (ANN) [4], and Extreme learning machine (ELM) [5] have produced positive results in the field of fault diagnosis. Among them, support vector machine (SVM) is rooted in statistical learning theory and optimization methods, with a simple structure that can effectively solve problems such as overfitting, local optima, and low convergence rate, greatly reducing the computational complexity of subsequent parameter optimization.…”

PMSM Sensorless Control Based on Moving Horizon Estimation and Parameter Self-Adaptation

“…Electronics 2024, 13, 2444 3 of 23 In order to derive the mathematical model of a SPMSM, it is necessary to assume that the following conditions are satisfied:…”

“…In the flux two-dimensional lookup table method, L dq and L qd are proposed to describe the cross-coupling effect. However, these parameter models fail to account for the back electromotive force and rotor inductance, and only a few models are capable of simulating magnetic saturation and cross-coupling effects [23,24]. Based on the high-carrier-frequency injection (CFI) method, the signal is superimposed on the fundamental phase voltage [25].…”

Research on Fault Diagnosis of Six-Phase Propulsion Motor Drive Inverter for Marine Electric Propulsion System Based on Res-BiLSTM

“…Compared with the traditional three-phase motor, the six-phase permanent magnet synchronous motor has obvious advantages in torque ripple, magnetomotive force waveform, and motor efficiency, and the multi-phase structure has the ability to realize high-power drive on the one hand, and the redundant structure on the other hand. It enables fault-tolerant operation of the motor after phase failure and improves the overall reliability of the propulsion system [18]. Therefore, six-phase PMSM is favored in large ships, luxury cruise ships, and other occasions that require high performance and reliability.…”