1,720,965 research outputs found
Closed-Loop, Flux-Weakening Control of Hybrid-Excitation Synchronous Machine Drives
No full textThis paper presents a closed-loop flux-weakening controller for hybrid-excitation synchronous machine drives based on separate regulation of amplitude and phase angle of the armature voltage. Operating point analysis is carried out to investigate the dynamic properties of the drive and to give guidelines in the tuning of the controller. Finally, experimental tests validating the theoretical derivations are performed on a prototype hybrid-excitation drive
Fault-Decoupled Instantaneous Frequency and Phase Angle Estimation for Three-Phase Grid-Connected Inverters
No full textFrequency and phase angle estimation is a key aspect for grid-connected inverters that are required to guarantee low-voltage fault-ride-through capability. Over the past two decades, a number of estimation algorithms have been proposed, mostly based on the well-known phase-locked loop (PLL). It has been demonstrated that standard PLLs do not perform correctly in abnormal grid conditions, due to the oscillations produced in the frequency and phase angle estimates by the voltage harmonics. This paper introduces a new, general approach to harmonic decoupling and presents a highly intuitive and simple scheme, applying it to an αβ-PLL; compensation of any desired number of harmonic components is possible. Two implementations of this decoupling scheme are presented. It is shown that the performances of the resulting fault-decoupled PLLs are comparable with those of other advanced frequency and phase angle estimation structures
Control strategy for bidirectional HBCS converter for supercapacitor applications
Full text linkThis paper proposes the basic average model and the design of the control system for the Half Bridge Current Source (HBCS) Bidirectional DC to DC Converter. This converter is intended to interface a High Voltage DC link and a Low Voltage DC Storage Device in transportation applications.
Firstly, the basics of the converter operation, high-level control and the simplified modeling are presented. Then, a cascaded control approach for the whole system is discussed and validated through simulations
Axial-Flux Hybrid-Excitation Synchronous Machine: Analysis, Design and Experimental Evaluation
No full textThis paper presents an axial-flux machine with
hybrid-excitation, in which the flux linkage can be regulated in
an extremely wide range by using a rotating excitation winding.
This machine shows a theoretically infinite constant power speed
range and also exhibits a high degree of fault tolerance against
uncontrolled generator operation. The machine has a singlestator
double-rotor topology, with one rotor mounting
permanent magnets and the other supporting the excitation
winding. After a review of the state-of-the-art of hybridexcitation
machines, the paper examines the principle of
operation of this machine. Subsequently, a prototype is designed,
analyzed with FEA, and built. Finally, experimental results are
reported to confirm the theoretical predictions and the benefits
and drawbacks of this novel topology
Ω shaped axial-flux permanent-magnet machine for direct-drive applications with constrained shaft height
No full textThis contribution investigates an original solution that can be used in the design of AFPM machines, whenever a constrained shaft height requirement penalizes a standard design. The machine is tailored for electrical traction, but the ideas that are set forth are valid for any application with constrained shaft height. Two design solutions are investigated that comply with the constrained shaft height: a standard Torus AFPM machine and an asymmetrically wound Torus machine, named Ω AFPM due to the shape of the stator. It is shown that the Ω AFPM machine has lower losses and a higher efficiency. FE simulations and experimental tests on a full-scale prototype confirm the validity of the proposed solution. © 2013 IEEE
Ω-Shaped Axial-Flux Permanent-Magnet Machine for Direct-Drive Applications With Constrained Shaft Height
No full textThis paper investigates an original solution that can be used in the design of axial-flux permanent-magnet (AFPM) machines whenever a constrained shaft height requirement penalizes a standard design. A machine is tailored for electrical traction, but the ideas that are set forth are valid for any application with a constrained shaft height. Two design solutions that comply with a constrained shaft height are investigated, i.e., a standard Torus AFPM machine and an asymmetrically wound Torus machine, which is named “Ω AFPM” due to the shape of the stator winding. It is shown that the Ω AFPM machine has lower losses and higher efficiency. Finite-element simulations and experimental tests on a full-scale prototype confirm the validity of the proposed solution
A general approach for the analysis and comparison of hybrid synchronous machines with single-axis or bi-axial excitation
No full text.Hybrid Excitation Synchronous Machines allow broad flux regulation, and therefore a very wide Constant Power Speed Range. Literature shows that it is possible to build them both with a Single-Axis and with a Bi-Axial excitation. This paper presents a unified approach for the analysis, comparison and performance prediction of the two structures. Finite element simulation and experimental tests are carried out on a Torus-type Axial-Flux prototype, which - having two rotors, one equipped with PM and one with WE - allows for an easy structure reconfiguration on the same machine
A comparison of hybrid excitation solutions for single-axis and bi-axial synchronous machines
No full textHybrid excitation synchronous machines are a class of machines that allow to reduce PM costs while keeping high torque density and that guarantee very high constant power speed range. They come in a wide variety of topologies and not all possible solutions have been explored yet. Aim of this paper is to provide a systematic analysis of all the possible configurations that can be obtained by changing the axis along which the hybrid excitation is placed. Both single-axis and bi-axial excitations are considered. A comparative analysis is carried out with respect to performance indices like torque capability, constant power speed range, power factor and losses
Closed-loop, flux weakening control for hybrid excitation synchronous machines
No full textThe paper presents a closed loop flux weakening controller for Hybrid Excitation Synchronous Machines. The control is achieved though regulation of the voltage amplitude and of the phase angle between voltage and current. An operating point analysis is carried out, in order to determine the dynamic behavior of the drive. Finally, experimental tests are conducted on a prototype of axial flux hybrid excitation machine
- …
