Piotr Bogusz

In the paper, alternative technologies of electric machines for domestic appliances were discussed. Nowadays, domestic appliances are used on a mass scale. In most households, there are domestic appliances where electric machines are used. Commutator motors are generally used in domestic appliances due to low costs of production. This is one of their few advantages, whereas to their disadvantages can include low energy efficiency and durability, which is limited by the sliding contact of brush-commutator. In consequence, devices equipped with these motors have low efficiency of energy conversion and are very often unreliable. In recent years, the vacuum cleaner became the receiver of relatively high power from the mains. Therefore, vacuum cleaners were covered by EU regulations. An increase of the energy efficiency of domestic appliances where electric machines are used is possible, among others, by introducing energy- saving technologies in electric machines. They are characterized not only by higher energy efficiency, but also by much longer failure-free operation of domestic appliance drive.

In this paper, the series configuration of pole winding connections in each phase of a three-phase 12/8 switched reluctance motor was analyzed. Based on the simulation model, the effect of magnetic couplings on motor properties was determined. Static characteristics were obtained for NNSS and NSNS configurations. Voltage, current, and electromagnetic torque waveforms were determined. Simulation results were verified through laboratory tests.

Two-phase switched reluctance motors are distinguished by their very simple design and belong to the group of high-speed motors. At high rotational speeds, losses in the core of a 4/2-pole switched reluctance machine are much lower than those occurring in a SRM with a larger number of phases. Unfortunately, a flaw of such a solution consists of a difficulty to obtain the starting torque in certain rotor positions. This occurs in the case of a symmetrical stator and rotor layout. To obtain the starting torque in any rotor position, an asymmetric design of rotor has been employed. In the framework of this study, a simulation model of such a machine was developed with the use of which motor characteristics were obtained for two specific working points, namely for very low and very high rotor speeds. Special attention was also focused on the problem of voltage control at high rotor speeds. On the grounds of the obtained results, an analysis of properties of the examined drive was performed from the point of view of the development of a practical control circuit for a two-phase SRM.

A hybrid drive of an unmanned aerial vehicle uses two mechanically coupled drives. In one of the drives, an electrical machine is used. Its role is not only limited to a motoring operation, e.g. during achieving the flight ceiling. The electric machine changes its operation into generating after reaching the flight ceiling, this allows not only meeting current electrical energy demands but also battery recharging. This paper presents the results of laboratory tests of a BLDC machine in motoring and generating operation. Mechanical characteristics of the motor for different supply voltages and external characteristics for generator were determined. The possible energy conversion efficiencies for both motoring and generating operations were determined.