Abstract: Conventional order analysis only can be applied on condition that the reference rotating speed is known, which limits its practical application if a tachometer installation is inconvenient. Further more, conventional order analysis also cannot be applied if the signal obtained is lack of rotating speed signal. In order to solve the problem mentioned above, a new order tracking analysis method without measuring the rotating speed is proposed, which is based on the instantaneous frequency estimation theory and energy centrobaric correction method. The proposed method can synchronously extract the reference speed and the amplitude of each order respectively. Moreover, the algorithm is simple to implement and easy to calculate, and the self-adaptive frequency resolution has little influence on the analysis precision of this method. Furthermore, the test equipment is simplified and the test cost is also reduced. Simulation and experiment results show that the proposed method is effective and practical, so the application range of order analysis will be extended.

Key words: Energy centrobaric correction, Instantaneous frequency, Order tracking, Spectrum correction