Piotr Wygonik

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.

Engine and multitask airplane integration: criteria of engine parameters selection

Purpose – The paper aims to present a way of engine model integration, an aircraft (multitask) and the mission into the single model that allows to study, from the level of selection of the engine cycle parameters, the feasibility of a specific mission with the assumed aerodynamic characteristics exemplified by a multitask airplane. Design/methodology/approach – There were introduced dimensionless geometric and energetic criteria, binding parameters of the engine and the airplane. The following models were built: of the turbofan engine and the aircraft movements with the application of these criteria, creating a dimensionless model allowing for measuring the impact of engine design parameters on the efficiency of the mission undertaken. Findings – The results were limited to the presentation of the impact of circuit parameters, such as engine TIT, OPR, BR on the defined criteria. The application of dimensionless criteria reduced the dimension of the task. Practical implications – The presented method can ...

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.

Criteria for the assessment of the engine efficiency of the multi-purpose aircraft missions

The problem of design parameters selection of the turbine engine is the most important task at the preliminary design stage of the multi-purpose aircraft. A special feature of the multi-purpose aircraft mission is a sudden (even pulse) weight change, especially its decrease as a result of discharge of cargo bombing or rockets due to the ammunition consumption during air combat manoeuvring. In this article the attempt to use economic and mass criteria to assess the impact of the type of air missions on the choice of the design parameters of the engine was done. As the design, parameters there were selected the following measures: compression ratio, the turbine temperature and the bypass ratio. A mathematical model of the engine – aircraft – air task system was built (taking into account the flight conditions, the mission elements – the subsonic and supersonic flight, flight time, thermo-gas-dynamic and mass model of the engine). The model enables to conduct the simulation research of the complex flight missions and their assessment on the basis of the constructed criteria. The model includes a parametric description of physical processes in the turbofan engine, thereby allowing a direct assessment of the impact of the selection of engine parameters on the effectiveness of the mission. The paper presents the results of calculations according to the classical criteria (e.g. kilometre fuel consumption, specific fuel consumption of the engine). New criteria for evaluation were presented; they are the energy efficiency of complex mission of an aircraft and the relative total and specific fuel consumption. The values of circuit parameters that need to be taken as design constraints for the engine to allow the implementation of the aviation missions were determined. The results are shown in an illustrative way on the number of graphs.

PROSPECTIVE ALTERNATIVE PROPULSION SYSTEMS FOR UNMANNED AERIAL VEHICLES

The paper presents selected issues concerning alternative power sources and propulsion systems meant for unmanned aerial vehicles (UAVs). The implementation of new propulsions in aviation is a laborious and long-term process, mostly due to safety and economical restrictions and requirements. Broadly, exploited solutions known from automotive industry may serve as a basis for development in aerospace technology, but cannot be applied without considering specific technical aspects (related to aircraft technology and flying objects physics). These aspects are mentioned in the text and some issues concerning suitability of types of aircraft are described. The paper presented contains a review of research on non-conventional propulsion systems for UAVs, conducted in Rzeszow University of Technology. Selected results of the research the fuel cell and the solar-cell UAVs and the aerial hybrid-electric drive test stand are shown in adequate pictures. The small-unmanned flying objects seem to be an accurate basis for such research. They allow reducing costs and improving safety in comparison to full-scale manned aircraft. They are also much quicker in manufacturing and easier to maintain and repair. Moreover, due to their various applications they may comprise the target market for this kind of propulsions. In particular, the issues of parallel hybrid-electric propulsions, fuel cell and solar-cell-assisted systems with appropriate examples are mentioned in the paper.

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.

An analysis of influence of open-winding faults on properties of brushless DC motor with permanent magnets

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 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.

Studies of the permanent magnet dc machine

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.