The problem of detecting and quantifying bar breakage harmonics in inverter-fed induction motors has not been solved by the time–frequency transforms present in the technical literature. The paper proposes a new transform, called dragon transform, to solve this problem. The dragon atoms are defined with shapes perfectly adapted to the harmonic trajectories in the time–frequency plane, no matter how complex they are, enabling the precise tracing of the harmonics to be detected. A quantification method is also proposed, which obtains for the first time in the technical literature, the time evolutions of the harmonic amplitudes during a complex transient such as the start-up and the steady state of an inverter-fed motor. The transform performance is validated testing the induction motor under different load levels.

技术文献中存在的时频变换尚未解决检测和定量逆变器感应电动机中的断条谐波的问题。本文提出了一种新的变换，称为Dragon变换，以解决此问题。定义的龙原子的形状完全适合时频平面中的谐波轨迹，无论它们多么复杂，都可以检测到谐波的精确轨迹。还提出了一种量化方法，该方法在技术文献中首次获得了在复杂瞬变（例如逆变器供电的电动机的启动和稳态）期间谐波幅度的时间演变。通过在不同负载水平下测试感应电动机，验证了转换性能。