2. Characterization of magnetic forces

2.1 Principle

We have seen that the condition of resonance of a magnetic force wave with the structure concerns both its spatial frequency (order) and its temporal frequency. In order to analytically determine the orders and frequencies of the force waves present in synchronous machines, thus enabling us to qualitatively predict their vibro-acoustic behavior, but also to facilitate the interpretation of experimental measurements, one method consists in expressing their harmonic content by replacing each source term by its Fourier series, as presented in