# TRANSACTIONS ON ELECTRICAL ENGINEERING

ISSN 1805-3386

April 6, 2020

## 2016 No.1

### Influence of the Stator Winding Vibration on the Insulation System Lifetime

Stauber, J., Kuruc, T., Pašek, R., Smolík, L., Krupauer, P.

The article deals with establishing of natural frequencies at the stator endwinding in stage of design of the machine (generator) and then measurement of the mode shapes (modal analysis on a real machine).

Keywords: stator winding, endwinding, modal analysis, mode shape, natural frequency

### Model Predictive Control for Offset-Free Reference Tracking

Belda, K.

The paper deals with the offset-free reference tracking problem of the Model Predictive Control (MPC). That problem is considered for a class of the constant or occasionally changed constant reference signals. Proposed solution arises from a simple subtraction of the ARX model of two consecutive time steps. The solution is adapted to a state-space form and it corresponds to usual predictive control design without increase of the design complexity. The construction of the prediction equations and predictive controller structure is explained in the paper.

Keywords: offset-free reference tracking, predictive control, ARX model, state-space model, multi-input multi-output system, robotic system, mechatronic system

### A Mathematical Model of Thermal Processes in the Empty Electric Muffle Furnace

Lucák, J.

The paper is focused on heating within the electric resistance furnaces. Muffle resistance furnaces were chosen as a subject of the examination. The first part of the paper is aimed to describe the examined object from technology and construction points of view. The issue of a mathematical model of the muffle furnace is explained in the next chapter. The main part of the paper is aimed to divide the furnace into the lumped thermal capacitances and to create the system of temperature differential equations of state that characterize the object.

Keywords: muffle furnace, thermal process, heating element, furnace lining and mathematical model

### Modified Biaxial Accelerometer Framework in G-sensing Mode

Roháč, J., Šipoš, M., Ďaďo, S.

This paper deals with an acceleration measuring unit, which uses two biaxial accelerometers, and compares its performance with a typical triaxial framework. In cases of small aircrafts, UAVs, robots, or terrestrial vehicle navigation units utilizing sensors manufactured by a MEMS technology are preferred due to their cost-effectiveness. In order to suppress imperfections of the measuring system (noise, drift, nonlinearities, small sensitivity) a solution based on the difference configuration of accelerometers is proposed.

Keywords: accelerometers, attitude control, data processing, inertial navigation