8 research outputs found
Modular Medium-Voltage Grid-Connected Converter with Improved Switching Techniques for Solar Photovoltaic Systems
Β© 1982-2012 IEEE. The high-frequency common magnetic-link made of amorphous material, as a replacement for common dc-link, has been gaining considerable interest for the development of solar photovoltaic medium-voltage converters. Even though the common magnetic-link can almost maintain identical voltages at the secondary terminals, the power conversion system loses its modularity. Moreover, the development of high-capacity high-frequency inverter and power limit of the common magnetic-link due to leakage inductance are the main challenging issues. In this regard, a new concept of identical modular magnetic-links is proposed for high-power transmission and isolation between the low and the high voltage sides. Third harmonic injected sixty degree bus clamping pulse width modulation and third harmonic injected thirty degree bus clamping pulse width modulation techniques are proposed which show better frequency spectra as well as reduced switching loss. In this paper, precise loss estimation method is used to calculate switching and conduction losses of a modular multilevel cascaded converter. To ensure the feasibility of the new concepts, a reduced size of 5 kVA rating, three-phase, five-level, 1.2 kV converter is designed with two 2.5 kVA identical high-frequency magnetic-links using Metglas magnetic alloy-based cores
ΠΠ°Π³Π½ΠΈΡΠΎΠΌΡΠ³ΠΊΠΈΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΠΎΡΠΎΡΠΊΠΎΠ² ΠΆΠ΅Π»Π΅Π·Π° Π΄Π»Ρ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² Π΄Π²ΡΡ ΡΡΠ°ΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ
An experimental prototype of electric motor on permanent (FeNdB) magnets with switchable magnetic flux with two sectioned stators and a rotor using SMC material based on encapsulated metal powders has been developed. The method of manufacture of magnetic cores by powder metallurgy method on the basis of magnetically soft encapsulated titanium dioxide composites has been developed, including computer modeling of magnetic cores components, creation of tooling for their manufacture by pressing and selection of technological modes of pressing. Press set for manufacturing stator components by pressing in the form of a mold was made of hardened 5XHB steel. With its use magnetic components for twostator combined electric motor are pressed. The main electromagnetic characteristics of the components were measured with an express magnetometer. Complex studies showed that the magnetic components have sufficient strength and the necessary electromagnetic characteristics to create a two-stator combined electric motor of this type. An experimental sample of electric motor with maximum power of 15 kW was created on the basis of manufactured magnetic components. Advantages of composite material over electrical steel and other soft magnetic alloys allow providing their wider application in electric machines in order to increase specific power at high speed of rotation with less losses.Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠΉ ΠΎΠ±ΡΠ°Π·Π΅Ρ ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ Ρ ΠΏΠ΅ΡΠ΅ΠΊΠ»ΡΡΠ°Π΅ΠΌΡΠΌ ΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠΌ ΠΏΠΎΡΠΎΠΊΠΎΠΌ Ρ Π΄Π²ΡΠΌΡ ΡΠ΅ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΡΠΌΠΈ ΡΡΠ°ΡΠΎΡΠ°ΠΌΠΈ ΠΈ ΡΠΎΡΠΎΡΠΎΠΌ Π½Π° ΠΏΠΎΡΡΠΎΡΠ½Π½ΡΡ
(FeNdB) ΠΌΠ°Π³Π½ΠΈΡΠ°Ρ
Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ΠΌ SMC-ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΊΠ°ΠΏΡΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠΎΡΠΎΡΠΊΠΎΠ². Π‘ΠΎΠ·Π΄Π°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΌΠ°Π³Π½ΠΈΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ² Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ΠΌΠ°Π³Π½ΠΈΡΠΎΠΌΡΠ³ΠΊΠΈΡ
ΠΊΠ°ΠΏΡΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
Π΄ΠΈΠΎΠΊΡΠΈΠ΄ΠΎΠΌ ΡΠΈΡΠ°Π½Π° ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΎΠ² ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΠΎΡΠΎΡΠΊΠΎΠ²ΠΎΠΉ ΠΌΠ΅ΡΠ°Π»Π»ΡΡΠ³ΠΈΠΈ, Π²ΠΊΠ»ΡΡΠ°ΡΡΠ°Ρ Π² ΡΠ΅Π±Ρ ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΠΎΠ΅ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΠΌΠ°Π³Π½ΠΈΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ², ΡΠΎΠ·Π΄Π°Π½ΠΈΠ΅ ΠΎΡΠ½Π°ΡΡΠΊΠΈ Π΄Π»Ρ ΠΈΡ
ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΡΠ΅ΡΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ Π²ΡΠ±ΠΎΡ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΠΆΠΈΠΌΠΎΠ² ΠΏΡΠ΅ΡΡΠΎΠ²Π°Π½ΠΈΡ. ΠΡΠ½Π°ΡΡΠΊΠ° Π΄Π»Ρ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΡΡΠ°ΡΠΎΡΠ° ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΡΠ΅ΡΡΠΎΠ²Π°Π½ΠΈΡ Π² Π²ΠΈΠ΄Π΅ ΠΏΡΠ΅ΡΡ-ΡΠΎΡΠΌΡ ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½Π° ΠΈΠ· Π·Π°ΠΊΠ°Π»Π΅Π½Π½ΠΎΠΉ ΡΡΠ°Π»ΠΈ 5Π₯HB. Π‘ Π΅Π΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ΠΌ ΡΠΏΡΠ΅ΡΡΠΎΠ²Π°Π½Ρ ΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠ΅ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΡ Π΄Π»Ρ Π΄Π²ΡΡ
ΡΡΠ°ΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ. ΠΡΠ½ΠΎΠ²Π½ΡΠ΅ ΡΠ»Π΅ΠΊΡΡΠΎΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½Ρ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΡΠΊΡΠΏΡΠ΅ΡΡ-ΠΌΠ°Π³Π½Π΅ΡΠΎΠΌΠ΅ΡΡΠ°. ΠΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, ΡΡΠΎ ΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΡ ΠΎΠ±Π»Π°Π΄Π°ΡΡ Π΄ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎΠΉ ΠΏΡΠΎΡΠ½ΠΎΡΡΡΡ ΠΈ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΡΠΌΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΠΌΠ°Π³Π½ΠΈΡΠ½ΡΠΌΠΈ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠ°ΠΌΠΈ Π΄Π»ΡΡΠΎΠ·Π΄Π°Π½ΠΈΡ Π΄Π²ΡΡ
ΡΡΠ°ΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ Π΄Π°Π½Π½ΠΎΠ³ΠΎ ΡΠΈΠΏΠ° ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΈΠ·Π³ΠΎΡΠΎΠ²Π»Π΅Π½Π½ΡΡ
ΠΌΠ°Π³Π½ΠΈΡΠ½ΡΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΡΠΎΠ·Π΄Π°Π½ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠΉ ΠΎΠ±ΡΠ°Π·Π΅Ρ ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ°ΡΡΠ΅ΡΠ½ΠΎΠΉ ΠΌΠΎΡΠ½ΠΎΡΡΡΡ 15 ΠΊΠΡ. ΠΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²Π° ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° ΠΏΠ΅ΡΠ΅Π΄ ΡΠ»Π΅ΠΊΡΡΠΎΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΠ°Π»ΡΡ ΠΈ Π΄ΡΡΠ³ΠΈΠΌΠΈ ΠΌΠ°Π³Π½ΠΈΡΠΎΠΌΡΠ³ΠΊΠΈΠΌΠΈ ΡΠΏΠ»Π°Π²Π°ΠΌΠΈ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΡΡ Π±ΠΎΠ»Π΅Π΅ ΡΠΈΡΠΎΠΊΠΎΠ΅ ΠΈΡ
ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π² ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΌΠ°ΡΠΈΠ½Π°Ρ
Ρ ΡΠ΅Π»ΡΡ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠ΄Π΅Π»ΡΠ½ΠΎΠΉ ΠΌΠΎΡΠ½ΠΎΡΡΠΈ ΠΏΡΠΈ Π²ΡΡΠΎΠΊΠΎΠΉ ΡΠΊΠΎΡΠΎΡΡΠΈ Π²ΡΠ°ΡΠ΅Π½ΠΈΡ Ρ ΠΌΠ΅Π½ΡΡΠΈΠΌΠΈ ΠΏΠΎΡΠ΅ΡΡΠΌΠΈ
Design of segmental rotor and non-overlap windings in single-phase fefsm for low torque high speed applications
In this research, a new structure of single-phase field excitation flux switching motor
(FEFSM) using segmental rotor structure and non-overlap windings arrangement is
proposed in order to overcome the drawbacks of low torque and small power
performances due to their longer flux path in the single-phase FEFSM using salient
rotor structure and overlap windings arrangement. The objectives of this study are to
design, analyse and examine performance of the proposed motor, to optimize the
proposed motor for optimal performances, and to develop the proposed motor
prototype for experimental performance validation. The design and analyses thru 2Dfinite
element analysis (FEA) is conducted using JMAG Designer version 15, while
deterministic optimization method is applied in design optimization process. To
validate the 2D-FEA results, the motor prototype is developed and tested
experimentally. Based on various rotor poles analysis, a combination of 12 pole 6 pole
(12S-6P) has been selected as the best design due to their highest torque and power
capability of 0.91 Nm and 277.4 W, respectively. Besides, the unbalance armature
magnetic flux of the proposed FEFSM using segmental rotor has been resolved by
using segmental rotor span refinement. The balanced armature magnetic flux
amplitude ratio obtained is 1.002, almost 41.2% reduction from the initial design. In
addition, the optimized motor has increased maximum torque and power by 80.25%
to 1.65 Nm, and 43.6% to 398.6W, respectively. Moreover, copper loss of the
optimized design has decreased by 9.7%%, hence increasing the motor efficiency of
25.3%. Finally, the measured results obtained from the prototype machine has
reasonable agreement with FEA results, proving their prospect to be applied for
industrial and home appliances
Flux switching machine design for high-speed geared drives
Electrical machines capable of high-speed operation are key technology used in many modern applications, such as gas turbine electrical systems, high-speed fly-wheels, turbochargers, and computer numerical control (CNC) machines. The use of geared high-speed machines to replace low-speed high torque drives has not been adequately researched to-date. The rationale of this thesis is to investigate a candidate high speed machine, namely flux switching machines to be used together with new types of core material with mechanical gearing to deliver high-torque and low speeds. Modern developments in advanced material technology have produced new magnetic materials capable of dealing with high resulting in very low losses in high speed machines. However, such metals typically have low mechanical strength, and they are found to be brittle. In order to manufacture electromechanical device with such new materials, it has to be reinforced with a mechanically strong structure. The use of multiple types of magnetic materials referred as a MMLC has been proposed in this thesis for high-speed machine design. In this research, a generic method using magnetic equivalent circuit to model flux switching machines (FSMs) is investigated. Moreover modeling, based on machine dimensions for multiphase FSMs having any pole and slot number has been introduced. The air-gap permeance modeling to simplify the magnetic circuit calculation of FSMs was also investigated in this thesis. It is shown that the permeability of magnetic material can be adjusted with the use of MMLC material. Using this feature, the FSM mathematical model is used to show the impact on electromagnetic performance using MMLCs and is shown to be beneficial. In order the evaluate the weight benefits of using geared high speed FSMs, the planetary gear systems are studies and their design constraints have been identified. An abstract form of weight estimation for given torque and speed requirements has been developed and validated using commercially available planetary gear specifications. FSMs together with gear boxes have been considered and it is shown that significant weight savings can be achieved at higher diameter and at high speeds
The integration of input filters in electrical drives
PhD ThesisThe integration of passive components such as inductors and capacitors has gained significant
popularity in integrated drive research, and future power electronics systems will require more
integrated and standardised packages. These give rise to better power density and improved
performance. However, packaging techniques and passive components have been considered a
technological barrier which is limiting advances in power electronics. The focus on size
reduction should be turned towards the passive components, such as converter chokes, DC-link
capacitors and electromagnetic interference (EMI) filters, and achieving greater power density
depends on innovative integration concepts, flexibility in structures and extended operating
temperature ranges while system integration and modularity are not mutually exclusive.
This research considers the possibility of integrating input power filter components into electric
machines. Particular attention is paid to the integration of electromagnetic line filter inductors
to give better utilisation of the motor volume and envelope. This can be achieved by sharing
the machineβs magnetic circuit. An LCL line filter has been chosen to be integrated with a gridconnected permanent magnet synchronous machine. Machines have been proposed in this study
for low speed (3000 RPM) and high speed (25000 RPM) operation. The two machines have
similar dimensions, but the low-speed machine is less challenging in terms of losses and filter
integration, so attention is directed more to the high-speed machine. Both are supplied with
low- and high-power drives at power ratings of 4.5 kW and 38 kW respectively.
Several novel techniques have been investigated to integrate filter inductors into the electrical
machines to produce a single mechanically packaged unit without significant increases in size
and losses. Different approaches have been simulated using finite element analysis (FEA) to
assess the effectiveness of the integration of passives within the machine structure. Each design
has been iteratively optimised to determine the best mass of copper and core for the integrated
filter inductors, targeting parity in power density when compared to traditional separate
packages. The research demonstrates that an approach utilising a double-slot stator machine
(named the integrated double slot (IDS) machine) with input filters wound into the outermost
slots is the most appropriate choice in terms of achieving higher power density.
The integrated filter inductors mimic the electromagnetic behaviour of the discrete industrially
packaged inductors but with a volume reduction of 87.6%. A prototype of the IDS machine
design of a 38 kW, 25000 RPM, including filter inductors was manufactured and testedthe General Electricity Company of Libya
(GECOL), the Engineering and Physical Sciences Research Council (EPSRC), and the
Engineering Doctorate scheme at Newcastle University
Improving high-speed electrical machines by amorphous metals
This dissertation is about the application of an amorphous magnetic material (AMM) to a sleeve-free interior permanent-magnet (PM) rotor of high-speed synchronous motors. Currently, surface-mounted PM rotors are commonly used in the high-speed motors. In order to protect the high-speed rotors from centrifugal forces, high-strength non-ferromagnetic sleeves are required. This results in a reduced torque density, lowered flux-weakening ability, and highen losses of the motor caused by pulse-width-modulation (PWM) voltage. Hence, a sleeve-free rotor structure is beneficial.
AMM has been used for transformers and inductors for decades. It is well-known due to its low core losses. However, because of its high hardness and brittleness, slotting becomes a key obstacle to its application in electrical machines. Hence, this material has not been widely applied in the electrical machines yet. An important property, the high mechanical strength of the AMM has been ignored eagerly. In this work, an interior PM rotor made from AMM for high-speed operation is studied. The high mechanical strength and the low core losses of the AMM are fully taken use of. Because of the difficulty in slotting of the AMM, this material is not used for the stator and a conventional silicon steel will be used.
In order to fulfill the proposed high-speed rotor, the properties of the AMM in terms of electromagnetics and mechanics are experimentally studied. The influences of the mechanical stress and temperature on the electromagnetic properties of the AMM cores are well studied. Based on the measured data, a prototype is designed and optimized in terms of electromagnetics, mechanics and thermal behaviors. To ensure the success of the prototype, the slotting methods are also investigated and wire electrical discharge machining method is selected for manufacturing of the AMM rotor core. In order to show the advantages and disadvantages of the proposed high-speed AMM rotor, a surface-mounted PM rotor covered by a carbon-fiber sleeve is designed as a comparison. Since the influences of the PWM inverter on the losses of the high-speed motors are significant and this problem has not been thoroughly investigated before, the dissertation goes into a further research on it to fill the gap in this field.
Finally, two prototypes are built and tested. The design results are verified through experiments. It is verified that by applying the AMM to the proposed rotor, the performance of the high-speed PM motor is significantly improved, such as better flux weaking ability, higher torque and power densities and higher efficiency. Based on the tested data of the prototypes, it is confirmed that the AMM has high potential in the application of high-speed high-power-density PM motors