Non-Salient Brushless Synchronous Generator Main Exciter Design for More Electric Aircraft (original) (raw)
Related papers
2009
Summary . In this paper a hybrid excitation system for a br ushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid) is presented. A conception of a dual-stator hybrid exciter is proposed. Comparison study of classical and hybrid exciter has been carried out. For the electromagnetic calculation two approaches have been applied: analytical approach (based on the circuit model and sizing equations) a nd numerical approach (using field simulator FLUX2D). Provisional design calculations have been performed using the analytical approach. Next, to verify the calculatio n results and to optimise the magnetic and electric circuit of the machine, the field simu lator FLUX2D has been used.
High-Performance Generator for a New Generation of Aircrafts
International Journal of Electrical and Computer Engineering (IJECE), 2017
The article describes multidisciplinary design process of high-performance electric generator for advanced aircrafts by analytical methods and computer modeling techniques (electromagnetic, thermal and mechanical calculations). New technical solutions used in its development are described. The main ideas are revealed of the method of EG voltage stabilization we used. To improve the heat dissipation efficiency, we have developed a new cooling system, and provide its study and description in this paper. The advantages of this cooling system include the fact that EG is made with dry, uncooled rotor. This allowed eliminating additional pumps, and significantly reducing the size of CSD. According to the results of our study, we created an experimental full capacity layout, and its studies are also provided in this paper.
This paper presents a novel salient pole synchronous generator i.e. permanentmagnet-assisted salient-pole synchronous generator (PMa-SGs). Due to saturation of conventional synchronous generators (SGs), permanent-magnet-assisted salientpole synchronous generators (PMa-SGs) are presented. PMa-SGs are a new type of salient-pole synchronous machines with extra permanent magnets (PMs) between the adjacent pole shoes. Placing PMs between adjacent pole shoes leads to a reduction in flux saturation plus an increase in armature flux linkage. In other words, the generator can operate at higher capacity. In this paper, a comparative study is carried out between conventional SGs and PMa-SGs based on finite element analysis (FEA). This is done via simulation of a PMa-SG compared to a conventional SG. Simulation Results show superiority of PMa-SGs over SGs. In fact, in PMa-SG maximum flux density in stator core is increased and pole bodies are not saturated. Besides, PMa-SG has higher flux linkage compared to conventional SG. Therefore, higher voltage could be produced in the generator. In other words, the output performance of the PMa-SG is considerably better than that of a conventional SG.
Study of salient poles synchronous generator by finite elements analysis
2013 12th International Conference on Environment and Electrical Engineering, 2013
This paper presents the finite elements analysis (FEA) of a salient poles synchronous generator. The goal of this analysis is to determine the machine parameters in steady-state regime and in transient regime respectively. The used FEA techniques and obtained results for a case study will be presented as well. Finally the FEA results will be compared to the experimental ones and a 2D transient with motion analysis will be performed.
Analysis of brushless DC generator incorporating an axial field coil
Energy Conversion and Management, 2011
This paper describes the magnetic analysis and experiment of a three-phase field assisted brushless DC (BLDC) generator. Unlike conventional BLDC generators, the permanent magnet is replaced with an assisted field winding. The stator and rotor are constructed with two dependent magnetically sets, in which each stator set includes nine salient poles with coil windings, and the rotor comprises of six salient poles. Other pole combinations also are possible. This construction is similar to a homopolar inductor alternator. The DC current in the assisted field winding produces axial flux which makes the rotor magnetically polarized at its ends. The magnetic field flows axially through the rotor shaft and closes through the stator teeth and the machine housing. To evaluate the generator performance, two types of analysis, namely the numerical technique and the experimental study have been utilized. In the numerical analysis, 2-D finite element (FE) analysis has been carried out using a MagNet CAD package (Infolytica Corporation Ltd.), to confirm the accuracy of the predicted flux-linkage characteristics, whereas in the experimental study, a prototype BLDC generator was constructed for verifying the actual performance. Furthermore, the evaluation method based on a hybrid numerical method coupling the finite element (FE) analysis and boundary element (BE) method, has been carried out to confirm the accuracy of the 2-D FE analysis simulation results. It provides not only confirmations of the investigation in results but also exact illustration for magnetic field distribution for this complex generator geometry.
IEEE Transactions on Magnetics, 2004
This paper models and simulates a salient-pole synchronous generator using a modified winding function theory and more precise stator and rotor winding distribution with dynamic eccentricity between the stator and rotor. Air-gap permeance is also computed more accurately compared to currently available methods. Inductances with this method are compared to those obtained from other methods and it is shown that the results are closer to those obtained from finite element computations. Finally, the calculated inductances are used in a coupled electromagnetic model for simulation and studying the frequency spectrum of the stator line current in the presence of dynamic eccentricity.
2017 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD), 2017
Objective of this paper is to provide design recommendations to improve the performance and power density of a 400kVA salient-pole synchronous generator, without exceeding the limitations due to critical parameters such as total harmonic distortion of the no-load voltage. Preliminarily, a finite-element analysis of the considered machine is carried out, aiming at validating the inherent model against experiment measurements. An in-detailed sensitivity analysis of the machine's design parameters that mostly affect the performance of the platform under investigation is performed. It has been found that the position and the shape of axial ventilation ducts, as well as the stator slot shape do not affect the electromagnetic performance in a significant way and it can be highly beneficial from a thermal point of view, resulting in reduced rotor temperatures. Additionally, the shape of the salient poles and the damper winding arrangement can produce positive effects on the general performance, particularly allowing for an improved voltage THD and power density of the machine being studied in this paper.
Aerospace Electric Generator Specification and Selection - Opportunities and Challenges
Proceedings of the 10th Aerospace Technology Congress, October 8-9, 2019, Stockholm, Sweden, 2019
The goal of this work is to specify and investigate suitability of a number of selected permanent magnet synchronous machine (PMSM) topologies to be mounted directly on a low pressure shaft (LPS) of a geared turbofan engine. The starting point of the work is to explore the status of electrical machines for more electric engine in order to study different design aspects when identifying and defining the designs. Even though the high flexibility and power density is anticipated from the system electrification the reliability is one of the most important aspects for the machine topology development and faultlessness can compromise desired performance. Large inner diameter of LPS and wide speed range are challenging the selection and specification of PMSM. The design initialisation is carried out by looking for more fault tolerant arrangements between machine windings and power converter topologies and appropriate rotor layouts that can provide excitation and constructional stability. Design space exploration is carried out on surface mounted Halbach array PMSM with distributed winding in the stator as one of the machine types that is best suited for high power density and high-speed application. Machine design aspects on modular design for faultlessness and cooling integration for enhanced thermal management and higher power density are the arguments behind the sensitivity study carried out on interior permanent magnet synchronous machine with nonoverlapping concentrated winding. Six different magnetic core materials are compared to demonstrate that thin FeSi electromagnetic steel grades improve efficiency and FeCo materials mainly torque density but the machine may remain unsatisfactory in power and efficiency.