Michał Michna

Simulation of the remanence influence on the transient states of the single-phase transformer including feedback Preisach model

This paper presents the results of the experimental and simulation investigation concerning the influence of remanence in the core of a single-phase transformer at the no-load transient state. Experimental studies consisted of the discharge of the capacitor through the primary winding at several different values of the residual magnetic flux. The paper presents a model of the transformer test system, taking into account the magnetic hysteresis phenomenon based on the Preisach model with feedback. The model was used to simulate the transient and steady state of the test system, taking into account the value and the sign of the remanence in the toroidal tape wound core. It was concluded that the induction of remanence has a significant impact on the value of the inrush current. This model can be used for simulation of the transformer systems transient state, taking into account the magnetic hysteresis and the remanence.

SSFR test of synchronous machine for different saturation levels using finite-element method

In this paper the Standstill Frequency Response characteristics (SSFR) of saturated synchronous generator (SG) have been calculated using Finite Element Method (FEM) analysis. In order to validate proposed approach for unsaturated conditions FEM simulation from Flux2D software has been compared with the measurements performed on the 10 kVA, 4-poles synchronous machine ELMOR GCe64a of salient rotor construction, equipped with a damper winding. Then, using the validated FEM model SSFR characteristics of the saturated machine have been recalculated by performing the FEM simulations with the variation of the magnetic permeability parameter.

Design, modelling and analysis of a new type of piezoelectric motor. Multicell piezoelectric motor

This paper describes a new type of piezoelectric motor. The results, obtained in the field of piezoelectric motors, have pointed out that these motors have potentially high possibilities in the future special applications. The research work presents the design, simulations and parameters of the piezoelectric motor with three rotation-mode actuators. The motor is characterized by a high power, relative high speed and torque. The motor consist of stator with few (minimum 3) rotating mode actuators. The purpose of those efforts was to develop a new actuator dedicated for the embedded applications.

Comparative analysis of salient and non-salient pole brushless synchronous generator for application in autonomous electric power system

This paper presents a comparative study of two types of brushless synchronous generator for application in autonomous electric power systems (e.g. airplane power grid). Commercially used salient pole and a prototype non-salient pole high speed multi-pole brushless synchronous generator (BSG) have been presented. Comparative analysis of both types of the generator has been performed. Chosen simulation (using FEM and circuit models) and measurement results have been presented.

Zastosowanie modułu symulacji dynamicznej programu CAD w analizie układu napędowego elektronarzędzia

W referacie przedstawiono analize mechanicznego ukladu przeniesienia napedu elektronarzedzia (wyrzynarki elektrycznej) przy zastosowaniu Modulu Symulacji Dynamicznej (MSD) programu Autodesk Inventor (AI). Opracowano modele 3D poszczegolnych cześci elektronarzedzia i polączono je przy zachowaniu tzw. kinematyki odwrotnej. Przeprowadzono analize wplywu poszczegolnych wezlow kinetycznych na przebieg momentu na wale silnika elektrycznego. Wykazano, ktore wezly mają najwiekszy wplyw na wartośc średnią i harmoniczne momentu

Detection of inter-turn faults in transformer winding using the capacitor discharge method

Abstract The paper presents results of an analysis of inter-turn fault effects on the voltage and current waveforms of a capacitor discharge through transformer windings. The research was conducted in the frame of the Facility of Antiproton and Ion Research project which goal is to build a new international accelerator facility that utilizes superconducting magnets. For the sake of electrical quality assurance of the superconducting magnet circuits, a measurement and diagnostic system is currently under development at Gdansk University of Technology (GUT). Appropriate measurements and simulations of the special transformer system were performed to verify the proposed diagnostic method. In order to take into account the nonlinearity and hysteresis of the magnetic yoke, a novel mathematical model of the transformer was developed. A special test bench was constructed to emulate the inter-turn faults within transformer windings.

Low speed permanent magnet synchronous generator for vertical axis wind turbine

The paper presents design process and tests of a prototype low speed permanent magnet synchronous generator (PMSG) dedicated for the innovative vertical-axis wind turbine. The rated data of the designed generator are following: power − 15 kVA, voltage − 400 V (Y), rotation speed − 93.75 rpm. The design assumptions, chosen results of the design process and experimental tests of the prototype PMSG are presented. The considered PMSG can be used in low-power wind plants applied for vessels (ships, yachts) and stationary prosumers power installations. The whole project realization (concept, design, engineering documentation, building and testing) of the prototype low-speed PMSG was commissioned by company ALU ECO Sp. o.o. Gdansk, and co-financed by the Polish Agency for Enterprise Development (PAED).

Investigation of inter-turn fault in transformer winding using discharge method

The paper presents the results of an analysis of the inter-turn fault effects on the voltage and current waveform of the capacitor discharge through transformer winding. The research was done within the FAIR project for which a measuring and diagnostic system for testing the condition of electrical circuits of superconducting electromagnets system is being developed. Appropriate measurements and simulations of special transformer system were made to verify the proposed diagnosis method. A mathematical model was developed considering the nonlinearity and hysteresis of the transformer magnetic core. The special test bench was made to emulate the inter-turn faults in transformer windings.

Mathematical modeling of the overhead contact line for the purpose of diagnosticsof pantographs

Mathematical modeling of the overhead contact line for the purpose of diagnostics of pantographs

Nonlinear model of synchronous generator for autonomous electrical power systems analysis

This paper presents the nonlinear lookup table model for synchronous generator (SG) analysis. The saturation effects of the SG magnetic circuit have been considered. The saturated characteristic of the SG magnetic circuit are based on the open circuit saturation curve for magnetizing inductances. The model has been implemented into the Synopsys/Saber software using the MAST modelling language. To implement the no-load voltage characteristic of SG into the MAST model the table look-up tool has been used. Normal and fault operation of SG can be effectively studied. Developed model exhibits a network with the same number of external terminals as the real SG and represents its behaviour in terms of the electrical and mechanical variables as well. Accuracy and robustness of the nonlinear lookup table modelling approach has been confirmed by measurements performed on the 3 kVA synchronous generator.