Performance analysis and testing of a 250 kW medium‐speed brushless doubly‐fed induction generator

Llano

et al. 2017

J. eng.

Self Cite

In this work, a large-scale Brushless Doubly Fed Machine (BDFM) built in frame size D400 is tested at different operating conditions in order to examine its noise and vibration levels. A series of measurements were conducted on the machine to establish the main modes of excitation of vibration and noise developed by the machine. The harmonic spectrums of the vibration amplitudes are presented at two different rotor speeds at which the vibration level is highest, in order to determine the vibration components frequencies existed in the vibration spectrum. A harmonic analysis of the BDFM is then proposed in order to assess the sources of vibration in the machine.

Section: Speed Variationmentioning

confidence: 92%

“…To date, a number of large BDFMs have been made, for example in Brazil with a 75 kW machine [3], China with the design of a 200 kW machine [4] and the 250 kW BDFM reported by the authors in [5] and shown in Figure 2 on test bed. The latter was built in a frame size D400 as a steppingstone towards a megawatt scale BDFM wind turbine.…”

Section: Introductionmentioning

confidence: 99%

Experimental analysis of noise and vibration for large brushless doubly fed machines

Llano

et al. 2017

J. eng.

Self Cite

IEEE Trans. Ind. Electron.

“…The BDFM essentially behaves as a classical synchronous machine if the control winding is connected to a DC source, operating at so called natural synchronous speed under this condition. Note that the latter is half the synchronous speed of an equivalent DFIG having the same number of rotor poles which implies that a 2-stage, rather than a 3-stage, gearbox can be used for BDFG based wind turbines with immediately obvious reliability and economic benefits [9]. If a positive sequence frequency is applied to the control winding, i.e.…”

Section: A Background Theorymentioning

confidence: 99%

“…Another strong reliability advantage over the DFIM is the inherently medium-speed nature of the BDFG allowing the use of a simpler and more compact 2-stage gearbox as opposed to a high-speed 3-stage counterpart of DFIG wind turbines, which is less mechanically robust and prone to failures [9]. As shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Design and Performance Comparisons of Brushless Doubly Fed Generators With Different Rotor Structures

Zhang

Wang

et al. 2019

Abstract-The Brushless Doubly-Fed Generator (BDFG) shows the great potential for use in large variable speed wind turbines due to its high reliability and cost benefits of a partially-rated power electronics converter. However, it suffers from the compromised efficiency and power factor in comparison with conventional doubly fed induction or synchronous generators. Therefore, optimizing the BDFG, especially the rotor, is necessary for enhancing its torque density and market competitiveness. In this paper, a novel cage-assisted magnetic barrier rotor, called the hybrid rotor, is proposed and analyzed. The detailed analytical design approaches based on the magnetic field modulation theory are investigated. In addition, the machine losses and mutual inductance values using the proposed rotor designs are calculated and their performance implications evaluated. Finally, the comparative experimental results for two BDFG prototypes are presented to verify the accuracy and effectiveness of the theoretical studies.

“…The brushless doubly-fed machine is a variable speed electrical machine which shows particular promise in applications such as wind energy generation or as a VSD, but still needs design and thermal modelling verification [12]. The BDFM has two separate stator windings, which must be of different pole numbers to avoid direct coupling between them.…”

Section: Bdfm Machinementioning

confidence: 99%

Energy harvesting and wireless data transmission system for rotor instrumentation in electrical machines

Llano

Tatlow

et al. 2017

IET Power Electronics

Self Cite

It is desirable to measure rotor quantities such as currents and temperatures in an electrical machine for design verification and condition monitoring purposes. A Bluetooth module which sends data from the rotor was previously reported in literature, but this module was battery powered, and therefore the duration of the tests was limited. This paper presents a solution to this problem by developing a rotor-mounted power supply system which can harvest energy from the magnetic field inside the machine, by fixing an external loop to the rotor and making use of the induced voltage in the loop. A full-bridge rectifier, boost converter and battery charging module was developed to supply sufficient power to a bespoke Bluetooth transmission system and associated sensor circuitry.