**6. Model creation**

The model of an electric machine can be made in several ways. One of them is the use of modern CAD systems to create geometry and its subsequent import into the computing environment. Another option is to create a model directly in the Ansys (using DesignModeler).

Another choice is to use the RMxprt environment. This module is primarily designed for rapid calculations of electrical machines. It features an environment for fast input of electrical machine dimensions. At the beginning of the job, the user selects a template that matches the specific machine type. The user then enters the main machine dimensions, slot size and slot type, and other parameters using simple tables.

RMxprt contains the following electrical machine templates:


calculations of primitive function. Even greater influence can be experienced on the course of

For the sampling of the general signal, the so-called Nyquist condition is mentioned in the literature. This indicates that each frequency-limited time function can be replaced by samples

As shown in **Figure 4**, when this state is used for a complex signal (such as the vibration are complex), there has been a strong deformation of the entire calculated waveform. Determining the time step requires some experience and knowledge that leads to a compromise between

Electromagnetic simulation is a possible solution in the Maxwell program, which is one of the Ansys software package modules. Maxwell module is used to calculate the magnetic field on 2D and 3D models. The calculation itself is based on Maxwell's equations. These equations

∇.*B* = 0 (5)

∇.*D* = *ρ* (7)

where *E* is electric field intensity, *B* is magnetic flux density, *H* is magnetic field intensity, *J* is

.*μr*

.*εr*

is relative permeability of material.

current density on surface, *D* is electric flux density, and *ρ* is volume charge density.

Some of these parameters depend on the properties of the used material:

≥ 2.*f*

max is maximal frequency included in the signal.

max

Vibration Simulation of Electric Machines http://dx.doi.org/10.5772/intechopen.72266

max (3)

<sup>∂</sup>*<sup>t</sup>* (4)

<sup>∂</sup>*<sup>t</sup>* (6)

.*H* (8)

.*E* (9)

, the highest

201

the calculated waveforms of the vibrational signals, which are much more complicated.

*sam* <sup>=</sup> \_\_\_\_ <sup>1</sup> *Tsam*

taken with the *Tsam* period, which is equal to half of the overturned value of the *<sup>f</sup>*

the quality of the result and the time consumption of the calculation [4].

frequency contained in the sampling signal. Therefore:

*f*

**8. Electromagnetic simulation**

can be written in a differential form:

<sup>∇</sup>*xE* <sup>=</sup> <sup>−</sup>\_\_\_ <sup>∂</sup>*<sup>B</sup>*

<sup>∇</sup>*xH* <sup>=</sup> *<sup>J</sup>* <sup>+</sup> \_\_\_ <sup>∂</sup>*<sup>D</sup>*

*B* = *μ*<sup>0</sup>

is permeability of vacuum and *μr*

*D* = *ε*<sup>0</sup>

*sam* is sampling frequency and *<sup>f</sup>*

where *f*

where *μ*<sup>0</sup>

**Figure 3.** Models of induction machine generated by RMxprt: a) 2D model and b) 3D model.

User needs to know a lot of information to create a model in RMXprt. One of the items to know is the basic design dimensions. Furthermore, it is necessary to know how to place the windings in the grooves and also the dimensions of the individual wires. All of these parameters affect the end result [10] (**Figure 3**).
