Jan Prokop

Current harmonics analysis as a method of electrical faults diagnostic in switched reluctance motors

Diagnostic method of electrical faults in switched reluctance motors (SRM) based on current harmonics analysis is presented in this paper. The classification of electrical faults in SRMs has been discussed, simulation model and laboratory setup presented. For the SRM motor of 6/4 design the conclusions drawn from the tests conducted both in the simulated and laboratory conditions for regular operation and selected electrical faults. The electrical fault type found in the machine was determined on the content of harmonics of higher order in the source current. The conclusions are included.

A study of design process of BLDC motor for aircraft hybrid drive

A study of the design process of BLDC motor designated as a power source for an Unmanned Aerial Vehicle (UAV). It was assumed that the UAV would be powered by a hybrid system, where electric power source operates in parallel to a combustion engine. Geometry of the electric motor being designed is presented as well as how the shape and magnetizing method influence cogging torque and average torque of the motor. Regulation characteristics, instantaneous currents, voltages and electromagnetic torque values are presented. Motor performance was analyzed as well as losses versus deliberately selected control parameters.

An analysis of properties of the BLDC motor for unmanned aerial vehicle hybrid drive

The paper presents an analysis of a brushless dc motor (BLDC) design solution to be used in the hybrid drive for an unmanned aerial vehicle (UAV), where the designed machine can be operated as the combustion engine starter, generator, and motor. Solutions with external rotor are preferred due to necessity of minimization of the machine weight. Relatively low value of the supply voltage requires that parallel connections within each of the motor phases should be adopted. When selecting optimum pole-arcs of permanent magnets, the relevant analysis concerns not only their influence on the generated cogging torque, electromagnetic torque, and induced voltage, but also circulating currents resulting from the assumed configuration of stator windings. Waveforms of currents, voltages, and the electromagnetic torque are determined for a selected motor working point. Finally, conclusions concerning the analyzed motor are presented.

Performance analysis of Switched Reluctance Motor with asymmetric stator

Construction of the Switched Reluctance Motor (SRM) developed by the authors and designated as a driving system for the food processor, is presented in this paper. The 6/4 design motor is of asymmetric stator construction. Results of simulation calculations are presented in a form of static characteristics, as well as current and torque waveforms. An analysis of how the air gap thickness, the width of stator poles and rotor teeth influence motor performance. Laboratory test results obtained on the actual prototype motor are also given.

A study of dual-channel brushless DC motor with permanent magnets

The paper discusses the concept of brushless DC motor with permanent magnets for a high-reliability drive. The possibility of improvement of vehicle drive reliability was shown on the example of a motor designated to drive of a small electric vehicle. The drive reliability can be improved by using two independent power converters which supply a motor with distributed windings in a double star connection. Results of motor studies in single-channel and dual-channel operation were presented. Conclusions concerning the analysed solution were formulated.

An analysis of operation of brushless DC machine used in unmanned aerial vehicle hybrid drive

This paper presents results of a study concerning operating modes of brushless DC machine (BLDCM) used in the hybrid drive designed for unmanned aerial vehicle (UAV). A mathematical model of the machine and a simulation model of the whole drive system are proposed. Structure of the parallel hybrid drive system is discussed. Results of simulations are presented for three different operation modes provided for the machine in the UAV drive system, i.e. engine starting, motoring operation with regulated airscrew speed, and generating operation. Finally, preliminary results of laboratory tests are presented.

A two-phase switched reluctance motor with asymmetrical rotor for a high-speed drive

The paper presents results of simulations and laboratory tests of a switched reluctance motor (SRM) designated to a high-speed drive. As the solution, a two-phase 4/2 motor has been proposed with asymmetric magnetic circuit of the rotor. The asymmetry was introduced intentionally in order to obtain the possibility to start the motor from any rotor position. Starting the motor from various initial rotor positions was tested in laboratory conditions. Further, the influence of control parameters on performance of the motor was analyzed.

A two-phase switched reluctance motor with reduced stator pole-arc

The paper presents analysis of a 4/2 switched reluctance motor design solution with reduced stator pole-arc. The analyzed model is designed to be used in a high-speed (45,000 rpm) drive. The stator pole-arc value change was accompanied by asymmetric structure of rotor magnetic circuit to allow start the motor from any rotor position. Static characteristics of the designed motor have been determined. Based on a field/circuit model, waveforms of currents, voltages, and the electromagnetic torque were determined. Exemplary torque characteristics, current and voltage waveforms were determined in laboratory conditions. Finally, conclusions concerning the designed machine with reduced stator pole-arc were presented.

Brushless DC Motor with Permanent Magnets for Unmanned Aerial Vehicle Hybrid Drive

Hybrid drive for a small unmanned aerial vehicle (UAV) must fulfil specified requirements. Parallel hybrid drive system is preferred in UAVs. Requirements for electrical machine used in a hybrid drive can be different because of variety of tasks which UAVs can realize. In the analysed case, the electric machine was predicted to operate as a combustion engine starter, a motor and a generator. Brushless DC motor 24/20 with permanent magnets was designed to be used in the hybrid drive. In the paper, original circuit-based mathematical model of brushless DC motor with permanent magnets known as the flux model which takes into account the nonlinearity of the magnetic circuit was presented. Waveforms of chosen parameters of the machine in different operation modes (starter, motor and generator) were determined based on the simulation model. In the motoring operation, dynamic variation of one control parameter (i.e. dynamic change of commutation point) was used to increase generated electromagnetic torque.

Research of influence of open-winding faults on properties of brushless permanent magnets motor

Abstract The paper presents an analysis of influence of selected fault states on properties of brushless DC motor with permanent magnets. The subject of study was a BLDC motor designed by the authors for unmanned aerial vehicle hybrid drive. Four parallel branches per each phase were provided in the discussed 3-phase motor. After open-winding fault in single or few parallel branches, a further operation of the motor can be continued. Waveforms of currents, voltages and electromagnetic torque were determined in discussed fault states based on the developed mathematical and simulation models. Laboratory test results concerning an influence of open-windings faults in parallel branches on properties of BLDC motor were presented.