**. . . .** Nowadays induction heating systems are widely used in the industry. Induction heating plays
an important role in industrial heating. It can heat very accurately depths and surface areas in
clean operating conditions with high power densities and short heat times. That is why they are
of permanent interest to researchers in recent years.

Flat inductor with constant step of winding has been developed as a prototype for heating up to temperature of 800-900

^{o}C
for stainless steel discs for agricultural tools, having outer diameter of 600-700 mm and thickness 6 mm before the hardening.
Having in mind the lack of theoretical analysis of the distribution of the electromagnetic and thermal field the requirement for
the specific distribution of the temperatures has not been fulfilled. This is the motivation for the numerical and experimental modelling,
for which a laboratory prototype has been created.

**. . . .**
**FEM MODELLING OF AN INDUCTION HEATING SYSTEM**

**. . . .** The results are obtained for time period of 600 seconds. The following procedure was
employed. The quasistationary electromagnetic problem was solved at every 10sec. taking into
account the temperature dependence of the magnetic permeability and electric conductivity. As
a result from the electromagnetic field analysis, the generated heat in the heated detail is
obtained and used as heat source during the next 10 sec. The thermal problem was solved as
nonlinear and temperature dependence of the thermal conductivity was taken into account

**. . . .**
**Impact of the geometric parameters of a cylindrical inductor on the thermal process**

This paper presents an analysis of the temperature distribution in a load while heating it by a cylindrical inductor.
The practical approach considered here enables its determination through modeling of the inductor-load system and fulfilling a computational procedure.
The main relationships used in solving the electromagnetic and the thermal problem are described. The basic geometric parameters to be determined are
the pitch of winding of the inductor and the distance between the inductor and the load, while analyzing the relationship between them and the temperature distribution.
The results thus obtained have been confirmed experimentally.

**A comparative analysis between analytical computation, model and experiment in inductive heating of cylindrical details**

The results obtained when studying induction heating by analytical relationships do not take into consideration any alteration of parameters.
A similar case is studying the details of a complex shape by modifying them into relatively simpler ones. Imprecise computations affect the distribution of electromagnetic
and thermal fields, which in turn affects the quality of thermal treatment. Modeling through application of numerical methods enables studying a particular process in a
particular detail without generalizing on all similar cases. Regardless of the approach, the obtained results differ from the real process because they do not account for
incidental interfering factors.

This paper offers a comparative analysis between analytical computation, model and experiment of a system of a cylindrical inductor and a load. The purpose is to determine
the factors affecting the error in modeling of induction devices.