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As high pointing accuracy spacecraft are being subjected to more stringent requirements on their micro-vibration environment, the reduction and mitigation of these disturbances has become of great importance. The reaction wheel assembly significantly impacts this environment, and as such improvements in bearing technologies have the greatest potential for performance gains. A current line of investigation are magnetic bearings, which generate a soft suspension mechanism thus damping vibrations and eliminating bearing wear. This study aims to explore the concept of Multipole Magnetic Bearings, focusing on radially segmented Halbach design, which introduce the ability of controlling the external magnetic field of the bearing to limit its effect on adjacent equipment., Aerospace Engineering

A disc-type rotor magnetic bearing with 3-pole magnet is considered in the paper. Based on analysing magnetic forces acting on the rotor, a coupling mechanism is identified, and a coordinate transformation is formulated to decouple acting forces. Thanks to the transformation, control design is straightforward for each control channel. The goal of the design is to keep the rotor at its desired equilibrium in the presence of disturbance and parameters variation. To achieve this goal, the controller is designed in discrete-time domain based on the linearized model first. Then, the disturbance is compensated by employing the one step delay technique. The validity and robustness of the controller are verified by various numerical simulations in which both linearized model and original nonlinear model are used.

Self-bearing machines offer a highly integrated solution to achieve the rotor drive and magnetic levitation within a single structure. Although the trend is toward a diminution in the number of actively stabilised degrees of freedom to reduce the requirement for sensors, power electronics and controllers, no self-bearing machine relying solely on passive phenomena has been successfully tested so far due to the restrictions highlighted by Earnshaw's Theorem. Recent researches have demonstrated, through electromechanical models and in-depth experimental investigations, that electrodynamic thrust self-bearing machines (EDTSBMs) can gather, within a combined winding, both the rotor axial passive suspension and motor functions. Nonetheless, the test benches implementing them still comprised external means to ensure the rotor radial and tilt support. In this context, this paper takes the study of EDTSBMs to the final step by combining them with two permanent magnet centring bearings, yielding the first fully passively levitated self-bearing machines. A reaction wheel demonstrator based on the latter is designed and sized according to an optimal approach. Thorough experimental analyses dealing with the axial forces that support the rotor and its resulting axial position as well as the drive torque are carried out, notably proving that stable fully passive levitation can be achieved. Finally, the motor and suspension currents as well as the corresponding losses are investigated.

Active magnetic bearings are used in a number of applications but their disadvantage is the high asynchronous error due to sensor noise amplification. In this paper a new radial position sensor for active magnetic bearings (AMB) based on linear optical encoders is presented. A commercial encoder scanning head faces a round scale with concentric, coplanar lines on its face. Because such a scale is not readily available, it is made by high precision micro machining and different options are compared. In experiments a measurement noise of 3.5 nm at 10 kHz bandwidth is achieved. In addition, a magnetic bearing is built to demonstrate the sensor in closed-loop.

Increasing demands for smaller and smarter devices in a variety of applications requires the investigation of process-machine-interactions in micro manufacturing to ensure process results that guarantee part functionality. One approach is the use of simulation-based physical models. In this contribution, methods for the physical modeling of high-precision air bearing and magnetic bearing spindles are presented in addition to a kinematic model of the micro milling process. Both models are superimposed in order to carry out investigations of the slot bottom surface roughness in micro end milling. The results show that process-machine-interactions in micro manufacturing can be modeled by the superposition of a physical model of the machine tool spindle taking cutting forces into consideration and a purely kinematic model of the machining process, providing the necessary tools for a variety of further investigations into process-machine-interactions in micro manufacturing.

A disc-type rotor magnetic bearing with 3-pole magnet is considered in the paper. Based on analysing magnetic forces acting on the rotor, a coupling mechanism is identified, and a coordinate transformation is formulated to decouple acting forces. Thanks to the transformation, control design is straightforward for each control channel. The goal of the design is to keep the rotor at its desired equilibrium in the presence of disturbance and parameters variation. To achieve this goal, the controller is designed in discrete-time domain based on the linearized model first. Then, the disturbance is compensated by employing the one step delay technique. The validity and robustness of the controller are verified by various numerical simulations in which both linearized model and original nonlinear model are used.

The results of the work carried out at the Department "Turbines and engines" aimed at creating a complex of vibration diagnostics of units at the AMP are presented., Представлены результаты работ, выполняемых на кафедре «Турбины и двигатели», направленных на создание комплекса вибрационной диагностики агрегатов на АМП.

A novel controller design procedure is proposed for a 5-degree-of-freedom (DOF) active magnetic bearing (AMB) system, based on sliding mode control (SMC) and neural network (NN). The SMC is used to achieve high robustness and fast response while the NN can compensate unmodeled uncertainty and external disturbance by on-line tuning algorithm. The proposed controller is compared with the well-tuned PID controller by simulations. The simulation results show the superior performance of the proposed controller., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage, Transport Engineering and Logistics

A novel controller design procedure is proposed for a 5-degree-of-freedom (DOF) active magnetic bearing (AMB) system, based on sliding mode control (SMC) and neural network (NN). The SMC is used to achieve high robustness and fast response while the NN can compensate unmodeled uncertainty and external disturbance by on-line tuning algorithm. The proposed controller is compared with the well-tuned PID controller by simulations. The simulation results show the superior performance of the proposed controller., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage, Transport Engineering and Logistics

The results of the work carried out at the Department "Turbines and engines" aimed at improving the quality of design, maintenance and repair of centrifugal natural gas superchargers equipped with magnetic suspension of rotors are presented., Представлены результаты работ, выполняемых на кафедре «Турбины и двигатели», направленных на повышение качества проектирования, обслуживания и ремонта центробежных нагнетателей природного газа, оснащенных магнитным подвесом роторов.

Permanent magnet bearing system utilizes the repulsive forces between the stator and rotor permanent magnets (PM) for the levitation of the system and it results a simplified axial control scheme. A repulsive type magnetic bearing system based on the above principle was fabricated in our laboratory. Material characteristics and the configuration of the permanent magnets are the central component for this type of bearing system. Due to aging or as both the magnets are repelling each other, there will be demagnetization of the permanent magnet, resulting the field distribution along the magnet's periphery nonuniform. In this paper the effect of this magnetization nonuniformity on the performance of the bearing system has been studied.

Many applications of the single-axis controlled repulsive-type magnetic bearing have been proposed earlier. However, both passive and active magnetic bearings are employed in most of such systems. In this paper, a new permanent magnet (PM) repulsive-type micromass measurement system is developed. The repulsive forces of the PM section are used effectively to keep the radial direction stable where the electromagnets, control circuits, and peripheral devices needed for controlling the unstable direction are simplified. The configuration, control design, and operating characteristics of the proposed system have been presented.

A repulsive-type magnetic bearing system has been fabricated in which the rotor of a vertical-shaft-type motor is levitated due to the repulsive force between two sets of permanent magnets. A novel arrangement of permanent magnets has been reported here, which has made the suspension of the rotor possible. The system is planned to be applied for pumping milks and other related products in the New Zealand dairy industry.

Rotor drops in magnetic bearing and unbalance in rotors have been objective of study for many years. The combination of these two well-known phenomena led to an interesting chaotic response, when the rotor touches the inner race of the back-up bearing. The present work explores the nonlinear rotor backup bearing dynamics both theoretically and experimentally using a fully instrumented test rig, where the position of shaft, its angular velocity and the contact forces between the shaft and the backup bearing are sampled at 25 kHz. The test rig is built by a removable passive magnetic bearing, which allows for simulation of magnetic bearing failure (loss of carrying capacity and rotor fall). The rotor is studied numerically as well as experimentally. A theoretical approach is given beforehand and supplies the basis of the study. Finally the presented results are commented on the point of view of nonlinear dynamics applied to the practical use. The theoretical and numerical analyses are shown through orbit plots, phase plans, Poincaré maps, force response in time and double sided spectrum. The latter is important to characterize the condition at different levels of unbalance between forward and backward whirl. Our preliminary results indicate that for smaller amount of unbalance the rotor swings at the bottom of the bearing, the more the unbalance increases, other dynamical behavior occur and some can be extremely harmful, since the rotor can be lifted from the contact state and return, starting to impact innumerable times without reaching a steady state.

Difficult-to-machine materials are still challenging the production industry. Examples are highly complex components of aircraft engines. Alongside innovative processes, also improved machine tool components are helping to comply with the demands of this task. This paper presents a swivel rotary table with an active magnetic bearing (AMB). Opportunities in machining through employing a workpiece-sided AMB are presented. The inherent capabilities to work as a sensor and actor as well as its stiffness and damping depend on the precise knowledge of the magnets characteristics. Therefore, a methodology to automatically identify the characteristic curve is presented.

Permanent magnets are increasingly being used as a result of the wider adoption of electrical devices and gadgets. There is a constant need for their optimization and size reduction, leading to new mathematical methods for their field calculation. The quality of electrical devices that contain permanent magnets is dependent on the magnetic material they are made of, their magnetization, and their size. Many different methods for permanent magnet field calculation are available, aiming towards the simplest and fastest analysis of magnetic structures in relation to different parameters. In most cases, analytical methods for permanent magnet field calculation based on the distribution of magnetic charges or Ampere's microscopic currents are limited to block and cylindrical structures. In order to overcome drawbacks of analytical and numerical methods, this theisis presents two additional, semi-numerical approaches.

A Magnetic Bearing Wheel (MBW) with inclined magnetic poles has been developed. This paper deals with the dynamic interactions between a satellite and the MBW. In the MBW-satellite system, the MBW rotor is coupled with the satellite by magnetic bearing forces and torques, and there exists some possibility that the magnetic bearing controller makes the satellite nutation unstable. In this paper, the equations of motion of the MBW-satellite system are formulated by Kane's method. Based on the stability analysis of this system, it is shown that the cross-feedback control of the rotor gimbal angle and integrator in an ordinary magnetic bearing controller are the instability factors responsible for satellite nutation. However, this nutation is stabilized with a cross-feedback control of the satellite angular rate estimated by a minimal-order observer from the magnetic bearing control torques. The effects of the disturbance feedback controller used in our study on the system stability are also considered, and the results show that the system stability is not affected by the disturbance feedback controller., 本論文は、傾斜磁極磁気軸受ホイールと宇宙機とのダイナミクス干渉解析について論じたものである。磁気軸受ホイールを搭載した宇宙機システムは、磁気軸受制御力およびトルクを介して、磁気軸受ホイール・ロータと宇宙機とが結合したシステムと見なすことができ、このとき磁気軸受制御系が宇宙機姿勢運動を不安定化する可能性がある。本論文では、傾斜磁極磁気軸受ホイール・宇宙機系運動方程式に基づいた姿勢安定性解析により、従来の磁気軸受制御系では、ロータ・ジンバル角度のクロスフィードバック制御と積分器の双方に起因して、宇宙機ニューテーションが不安定化することを示す。次にこのような問題に対して、最小次元オブザーバによる宇宙機角速度の推定と、これをクロスフィードバックする構成を追加した新たな磁気軸受制御系を適用することで、宇宙機ニューテーションを安定化できることを示し、さらに本構成に対して擾乱フィードバック制御系を追加した場合にも、系の安定性が保たれることを確認する。

This paper presents a novel attitude control device called 3 Dimensional Reaction Wheel (3DRW). 3DRW consists of a spherical mass which can rotate around arbitrary axes by magnetic levitation. 3DRW is 3-DOF (Degree Of Freedom) device with only one reaction mass which could make it possible to drastically reduce the weight and volume of the system as compared to existing reaction wheel. In addition to that, this device does not have mechanical contact between rotor and stator, so longer operating lifetime can be expected. In this paper, the concept of 3DRW is introduced, and the analysis and the result of simulations on the dynamics of rotation mass in a magnetic field are shown. Also the experiment setup of magnetic levitation and rotating, and its results are presented. Finally it is will mentioned how 3DRW system can be applied effectively for the small satellites., 通常、リアクションホイールは機械部を持つ。これにより接触による摩擦が生じるのでリアクションホイールの寿命が短くなる。また、リアクションホイールは剛体となるので設計が固定化される。特に小型衛星と呼ばれるものでは設計の固定化はミッションに制約を課すことに繋がる。これらリアクションホイールを用いることによって生じる問題を解決する1つの手段として本研究は3次元リアクションホイールを提案する。3次元リアクションホイールとは磁気浮上させた剛体球に回転磁場を与えることによって剛体球内に渦電流を誘導し、渦電流と回転磁場によって剛体球にはローレンツ力がかかる。このローレンツ力によって剛体球は回転し、角運動量を発生させる。3次元リアクションホイールは駆動部が浮上しているので機械部を持たない。これにより長期の運用を行う衛星に搭載することが可能となる。また、回転磁場任意軸周りに掛けることができるので3次元での回転が可能となり、1つの機器で3軸の姿勢を制御できる。ここで、重要となるのが剛体球を機械部(モータなど)を用いずに回転させることである。本研究では回転システムについて実験的に検証を行う。まず、剛体球を1次元回転させることによる基礎実験を行う。剛体球の浮上、回転について実験的に検証する。また、実験の結果を踏まえて3次元リアクションホイールのモデル化を行う。

One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation. Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias cu

One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation. Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias cu

Difficult-to-machine materials are still challenging the production industry. Examples are highly complex components of aircraft engines. Alongside innovative processes, also improved machine tool components are helping to comply with the demands of this task. This paper presents a design approach of a rotary table with an active magnetic bearing. Opportunities in machining through employing magnetic guides are presented and discussed in the beginning. In the following, a workflow for the magnetic bearing design in swivel rotary tables is proposed. The mentioned steps are executed based on a presently under design rotary table.

One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation. Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias cu

One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation. Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias cu

One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation. Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias cu

The rotating Kinetic Energy Storage System (KESS) is suitable as temporary energy storage in electric vehicles due to its insensitivity to the number of charge-discharge cycles and its relatively high specific energy. The size and weight of the KESS for a given amount of stored energy are minimized by decreasing the moment of inertia of the rotor and increasing its speed. A small and fast rotor has the additional benefit of reducing the induced gyroscopic moments as the vehicle turns. The very high resulting rotational speed makes the magnetic bearing an essential component of the system, with the Active Magnetic Bearing (AMB) being the most common implementation. The complexity and cost of an AMB can be reduced by integration with the electric machine, resulting in a bearingless and sensorless electric machine. This review article describes the usage of magnetic bearings for FESS in vehicular applications.

The purpose of this paper is to present a parameterized electromechanical model taking into account both the electromagnetic nature of the forces acting inside a magnetic bearing and the general rotating machinery aspects, as well as their interactions. This model specifically includes the effect of induced currents. These induced currents in the bearings are submitted to inductive and resistive effects, as well as skin effect, and the influence of these effects is considered. It is shown that the stability of a bearing may be analysed, based on this model. The parameters of the model are identified from experimental results for an existing semi-passive magnetic bearing, and it is shown that the forces predicted by the model are close to experimental measurements.

Рассмотрены особенности применения электромагнитных подшипников в газотурбинной установке, а также результаты исследования их работоспособности в энергоблоках. Приведены массогабаритные характеристики валопровода, включающего в себя роторы двигателя и турбогенератора. Описана конструкция системы и особенности ее отладки, Розглянуто особливості застосування електромагнітних підшипників в газотурбінній установки, а також результати дослідження їх працездатності в енергоблоках. Наведено масогабаритні характеристики валопроводу, який включає в себе ротори двигуна й турбогенератора. Описана конструкція системи та особливості її налагодження, Features of application of electromagnetic bearings in gas-turbine power plant to installation, and also results of research of their working capacity in power units are considered. Are brought mass-dimensional characteristics wire-shaft, the engine including rotors and a turbogenerator. The design of system and feature of its debugging is described

A direct drive generator used in wind turbine has high energy yield compared to other drivetrain topologies and low maintenance is expected as the technology matures. On the other hand direct drive generator weight and size increases rapidly when scaled up to larger units. This paper will investigate the possibility of weight reduction of large direct drive generator using magnetic bearings without compromising maintenance. Three different configurations using magnetic bearings i.e. single magnetic bearing concept, flexible rotor and hybrid concept have been analyzed. The results show that a combination of magnetic bearings and mechanical bearing with stiff radial structure and axial flexibility i.e. hybrid concept has the possibility to reduce weight of direct drive machine significantly compared to conventional design., Electrical Sustainable Energy, Electrical Engineering, Mathematics and Computer Science

A direct drive generator used in wind turbine has high energy yield compared to other drivetrain topologies and low maintenance is expected as the technology matures. On the other hand direct drive generator weight and size increases rapidly when scaled up to larger units. This paper will investigate the possibility of weight reduction of large direct drive generator using magnetic bearings without compromising maintenance. Three different configurations using magnetic bearings i.e. single magnetic bearing concept, flexible rotor and hybrid concept have been analyzed. The results show that a combination of magnetic bearings and mechanical bearing with stiff radial structure and axial flexibility i.e. hybrid concept has the possibility to reduce weight of direct drive machine significantly compared to conventional design., Electrical Sustainable Energy, Electrical Engineering, Mathematics and Computer Science

The purpose of this paper is to present a parameterized electromechanical model taking into account both the electromagnetic nature of the forces acting inside a magnetic bearing and the general rotating machinery aspects, as well as their interactions. This model specifically includes the effect of induced currents. These induced currents in the bearings are submitted to inductive and resistive effects, as well as skin effect, and the influence of these effects is considered. It is shown that the stability of a bearing may be analyzed, based on this model. The parameters of the model are identified from experimental results for an existing semi-passive magnetic bearing, and it is shown that the forces predicted by the model are close to experimental measurements.

Magnetic bearings are electromechanical systems. From a mechanical point of view, their modeling is plainly related to general rotor dynamics modeling. But the forces acting between the rotor and the stator are of an electromagnetic nature. This paper presents the analysis of the potentially unstable dynamical behavior of magnetic bearings. It adopts an electromechanical point of view and represents the forces acting on the system by dampers, springs, and an electrical phase shift. The coefficients of the model are found by parameter identification with a finite-element model of the system.

Diplomová práce je zaměřena na literární rešerši a popis magnetických ložisek za účelem návrhu standu pro demonstraci magnetické levitace. Simulovaný model je vytvořen za pomocí metody konečných prvků. Dále se zabývá výhodami a nevýhodami spolu s porovnáním s klasickými ložisky v pohonech. Je zde diskutován analytický návrh, jež je zjednodušený a zanedbává několik parazitních jevů. Tyto analýzy jsou následně diskutovány. Hlavní část návrhu a postupu výpočtů je pro 8-pólové heteropolární radiální aktivní magnetické ložisko. Výsledek návrhu je následně uplatněn na realizaci demonstrátoru., The master thesis is focused on literature research and description of magnetic bearings in order to create a design model of a stand for demonstration of magnetic levitation. The simulated model is developed using the finite element method. It also discusses the advantages and disadvantages along with a comparison with conventional bearings in drives. Analytical design is discussed here, which is also simplified and neglects several parasitic effects. These analyses are then discussed. The main part of thesis containe design and calculation for an 8-pole active radial heteropolar magnetic bearing. The result of the design is then applied to the realization of the demonstrator.

Diplomová práce se zabývá vytvářením mechatronického modelu hlavy obráběcího stroje dodané firmou TOSHULIN,a.s. za účelem tlumení vibrací. Mechanická část modelu je zalo-žena na modelování soustavy poddajných těles. Součástky jsou modelovány v MKP programu ANSYS a následně redukovány pomocí Craig-Bamptonovy metody. Soustava pružných těles je vytvářena v MBS programu ADAMS. Model je linearizován a následně redukován. Jako prvek aktivního tlumení využívá linearizovaný model magnetického ložiska. Pro řízení je navržen PID regulátor. V závěru je provedeno porovnání tlumeného a netlumeného modelu., The master’s thesis deals with building mechatronics model of machine tool head delivered by company TOSHULIN,a.s. for purpose of damping vibration. Mechanical part of the model is based on modeling of system of flexible bodies. Components are modeled in FEM program ANSYS and subsequently reduced using Craig-Bampton method. The system of flexible bo-dies is created in MBS program ADAMS. Model is linearized and subsequently reduced. As a element of active damping is used linearized model of magnetic bearing. For control is desig-ned PID controller. The comparison of damped and undamped model is conducted in the end.

Předkládaná diplomová práce se zabývá simulací rozběhu Lavalova rotoru uloženého v nelineárních vazbách. První část práce se zabývá rešeršní studií, která je zaměřena jak na popis Lavalova rotoru a pohybové rovnice pro případ tuhého a pružného rotoru, tak na popis a možnosti modelování hydrodynamických a magnetických ložisek, která byla pro práci vybrána. Druhá část práce je věnována simulacím rozběhu rotoru pro různé přístupy modelování hydrodynamických a magnetických ložisek. Pomocí simulací provedených v časové oblasti je vyhodnoceno a porovnáno dynamické chování Lavalova rotoru. Simulace jsou provedeny v MATLABu., The presented diploma thesis deals with simulation of Laval rotor supported by nonlinear bearings. The first part of thesis deals with research, which is focused on description of Laval rotor and motion equations for case of rigid and flexible rotor, also on description and modeling of hydrodynamic and magnetic bearing, which is considered in thesis. The second part of thesis deals with simulation of rotor for different approaches to modeling hydrodynamic and magnetic bearings. Using simulations performer in time domain, the dynamic behavior of Laval rotor is evaluated and compared. Simulations are performer in MATLAB.

Tato diplomová práce se zabývá návrhem hybridního magnetického ložiska. Jedná se o rozšíření problematiky běžných ložisek ve vysokootáčkových motorech. Práce je rozdělena do tří částí, kde se první část zabývá obecnou teorií magnetických ložisek. Druhá část se zabývá matematickým popisem ložiska. Třetí část se zabývá návrhem specifického hybridního magnetického ložiska. Návrh je proveden pro motor, pro který již bylo ložisko navrženo. Jedná se o motor o 45000ot/ min a výkonem 12kW. Cílem tohoto návrhu je vytvořit hybridní magnetické ložisko s magnety pro vytvoření stálého magnetického pole a cívkami pro regulaci sil ke stabilizaci rotoru a omezení vibrací. Praktický návrh zahrnuje matematický výpočet v programu MATLAB a počítačovou simulaci založenou na metodě konečných prvků v programu ANSYS Maxwell., The thesis deals with the design of a hybrid magnetic bearing. This is an extension of the issue of common bearings in high-speed motors. The work is divided into three parts. A general theory of magnetic bearings is described in the first part. The second part deals with the mathematical description of the bearing. A proposal of specific hybrid magnetic bearing is described in the third part. The bearing for the motor was already designed. It is a 45000rpm motor with a power output of 12 kW. This thesis aims to create a design of hybrid magnetic bearing with magnets to create a permanent magnetic field and coils to regulate forces to stabilize the rotor and limit vibrations. The practical design includes mathematical calculation in Matlab and computer simulation based on the finite element method in ANSYS Maxwell.

Požadavky vysokorychlostních aplikací společně se snahou snížit spotřebu elektrické energie vedou k návrhům nových typů ložisek. V posledních desetiletích bylo hledáno ložisko, které by dosáhlo pasivní levitace použitím běžných materiálů při pokojové teplotě. To vedlo k vývoji elektrodynamického ložiska, které pracuje na principu vířivých proudů. V současné sobě ještě není elektrodynamické ložisko dostatečně prozkoumáno a jsou potřeba další výzkumy. Cílem práce je nejprve teoretický popis moderních magnetických ložisek, zjednodušená analýza elektrodynamického ložiska a návrh konkrétního ložiska podle zvolených parametrů. Tato konstrukce bude následně simulována konečně prvkovou metodou pro ověření a posouzení jeho vlastností., High speed applications demands with a need for lower energy consumption lead to designing new types of bearings. In the last decades magnetic bearing, which would be able to obtain passive stable levitation using regular materials at room temperature, has been searched. This has lead to development of electrodynamic bearing based on eddy currents principle. Currently the electrodynamic bearings are still not fully explored and further research is needed. The aim of the work is to describe the theory about modern magnetic bearing, analysis and design of electrodynamic bearing according to given parameters. The finite element method is used for further analysis and evaluate behaviour of its properties.

Požadavky vysokorychlostních aplikací společně se snahou snížit spotřebu elektrické energie vedou k návrhům nových typů ložisek. V posledních desetiletích bylo hledáno ložisko, které by dosáhlo pasivní levitace použitím běžných materiálů při pokojové teplotě. To vedlo k vývoji elektrodynamického ložiska, které pracuje na principu vířivých proudů. V současné sobě ještě není elektrodynamické ložisko dostatečně prozkoumáno a jsou potřeba další výzkumy. Cílem práce je nejprve teoretický popis moderních magnetických ložisek, zjednodušená analýza elektrodynamického ložiska a návrh konkrétního ložiska podle zvolených parametrů. Tato konstrukce bude následně simulována konečně prvkovou metodou pro ověření a posouzení jeho vlastností., High speed applications demands with a need for lower energy consumption lead to designing new types of bearings. In the last decades magnetic bearing, which would be able to obtain passive stable levitation using regular materials at room temperature, has been searched. This has lead to development of electrodynamic bearing based on eddy currents principle. Currently the electrodynamic bearings are still not fully explored and further research is needed. The aim of the work is to describe the theory about modern magnetic bearing, analysis and design of electrodynamic bearing according to given parameters. The finite element method is used for further analysis and evaluate behaviour of its properties.

Tato diplomová práce se zabývá návrhem hybridního magnetického ložiska. Jedná se o rozšíření problematiky běžných ložisek ve vysokootáčkových motorech. Práce je rozdělena do tří částí, kde se první část zabývá obecnou teorií magnetických ložisek. Druhá část se zabývá matematickým popisem ložiska. Třetí část se zabývá návrhem specifického hybridního magnetického ložiska. Návrh je proveden pro motor, pro který již bylo ložisko navrženo. Jedná se o motor o 45000ot/ min a výkonem 12kW. Cílem tohoto návrhu je vytvořit hybridní magnetické ložisko s magnety pro vytvoření stálého magnetického pole a cívkami pro regulaci sil ke stabilizaci rotoru a omezení vibrací. Praktický návrh zahrnuje matematický výpočet v programu MATLAB a počítačovou simulaci založenou na metodě konečných prvků v programu ANSYS Maxwell., The thesis deals with the design of a hybrid magnetic bearing. This is an extension of the issue of common bearings in high-speed motors. The work is divided into three parts. A general theory of magnetic bearings is described in the first part. The second part deals with the mathematical description of the bearing. A proposal of specific hybrid magnetic bearing is described in the third part. The bearing for the motor was already designed. It is a 45000rpm motor with a power output of 12 kW. This thesis aims to create a design of hybrid magnetic bearing with magnets to create a permanent magnetic field and coils to regulate forces to stabilize the rotor and limit vibrations. The practical design includes mathematical calculation in Matlab and computer simulation based on the finite element method in ANSYS Maxwell.

Tato diplomová práce se zabývá návrhem hybridního magnetického ložiska. Jedná se o rozšíření problematiky běžných ložisek ve vysokootáčkových motorech. Práce je rozdělena do tří částí, kde se první část zabývá obecnou teorií magnetických ložisek. Druhá část se zabývá matematickým popisem ložiska. Třetí část se zabývá návrhem specifického hybridního magnetického ložiska. Návrh je proveden pro motor, pro který již bylo ložisko navrženo. Jedná se o motor o 45000ot/ min a výkonem 12kW. Cílem tohoto návrhu je vytvořit hybridní magnetické ložisko s magnety pro vytvoření stálého magnetického pole a cívkami pro regulaci sil ke stabilizaci rotoru a omezení vibrací. Praktický návrh zahrnuje matematický výpočet v programu MATLAB a počítačovou simulaci založenou na metodě konečných prvků v programu ANSYS Maxwell., The thesis deals with the design of a hybrid magnetic bearing. This is an extension of the issue of common bearings in high-speed motors. The work is divided into three parts. A general theory of magnetic bearings is described in the first part. The second part deals with the mathematical description of the bearing. A proposal of specific hybrid magnetic bearing is described in the third part. The bearing for the motor was already designed. It is a 45000rpm motor with a power output of 12 kW. This thesis aims to create a design of hybrid magnetic bearing with magnets to create a permanent magnetic field and coils to regulate forces to stabilize the rotor and limit vibrations. The practical design includes mathematical calculation in Matlab and computer simulation based on the finite element method in ANSYS Maxwell.

Požadavky vysokorychlostních aplikací společně se snahou snížit spotřebu elektrické energie vedou k návrhům nových typů ložisek. V posledních desetiletích bylo hledáno ložisko, které by dosáhlo pasivní levitace použitím běžných materiálů při pokojové teplotě. To vedlo k vývoji elektrodynamického ložiska, které pracuje na principu vířivých proudů. V současné sobě ještě není elektrodynamické ložisko dostatečně prozkoumáno a jsou potřeba další výzkumy. Cílem práce je nejprve teoretický popis moderních magnetických ložisek, zjednodušená analýza elektrodynamického ložiska a návrh konkrétního ložiska podle zvolených parametrů. Tato konstrukce bude následně simulována konečně prvkovou metodou pro ověření a posouzení jeho vlastností., High speed applications demands with a need for lower energy consumption lead to designing new types of bearings. In the last decades magnetic bearing, which would be able to obtain passive stable levitation using regular materials at room temperature, has been searched. This has lead to development of electrodynamic bearing based on eddy currents principle. Currently the electrodynamic bearings are still not fully explored and further research is needed. The aim of the work is to describe the theory about modern magnetic bearing, analysis and design of electrodynamic bearing according to given parameters. The finite element method is used for further analysis and evaluate behaviour of its properties.

Předkládaná diplomová práce se zabývá simulací rozběhu Lavalova rotoru uloženého v nelineárních vazbách. První část práce se zabývá rešeršní studií, která je zaměřena jak na popis Lavalova rotoru a pohybové rovnice pro případ tuhého a pružného rotoru, tak na popis a možnosti modelování hydrodynamických a magnetických ložisek, která byla pro práci vybrána. Druhá část práce je věnována simulacím rozběhu rotoru pro různé přístupy modelování hydrodynamických a magnetických ložisek. Pomocí simulací provedených v časové oblasti je vyhodnoceno a porovnáno dynamické chování Lavalova rotoru. Simulace jsou provedeny v MATLABu., The presented diploma thesis deals with simulation of Laval rotor supported by nonlinear bearings. The first part of thesis deals with research, which is focused on description of Laval rotor and motion equations for case of rigid and flexible rotor, also on description and modeling of hydrodynamic and magnetic bearing, which is considered in thesis. The second part of thesis deals with simulation of rotor for different approaches to modeling hydrodynamic and magnetic bearings. Using simulations performer in time domain, the dynamic behavior of Laval rotor is evaluated and compared. Simulations are performer in MATLAB.

Diplomová práce se zabývá vytvářením mechatronického modelu hlavy obráběcího stroje dodané firmou TOSHULIN,a.s. za účelem tlumení vibrací. Mechanická část modelu je zalo-žena na modelování soustavy poddajných těles. Součástky jsou modelovány v MKP programu ANSYS a následně redukovány pomocí Craig-Bamptonovy metody. Soustava pružných těles je vytvářena v MBS programu ADAMS. Model je linearizován a následně redukován. Jako prvek aktivního tlumení využívá linearizovaný model magnetického ložiska. Pro řízení je navržen PID regulátor. V závěru je provedeno porovnání tlumeného a netlumeného modelu., The master’s thesis deals with building mechatronics model of machine tool head delivered by company TOSHULIN,a.s. for purpose of damping vibration. Mechanical part of the model is based on modeling of system of flexible bodies. Components are modeled in FEM program ANSYS and subsequently reduced using Craig-Bampton method. The system of flexible bo-dies is created in MBS program ADAMS. Model is linearized and subsequently reduced. As a element of active damping is used linearized model of magnetic bearing. For control is desig-ned PID controller. The comparison of damped and undamped model is conducted in the end.

Diplomová práce se zabývá vytvářením mechatronického modelu hlavy obráběcího stroje dodané firmou TOSHULIN,a.s. za účelem tlumení vibrací. Mechanická část modelu je zalo-žena na modelování soustavy poddajných těles. Součástky jsou modelovány v MKP programu ANSYS a následně redukovány pomocí Craig-Bamptonovy metody. Soustava pružných těles je vytvářena v MBS programu ADAMS. Model je linearizován a následně redukován. Jako prvek aktivního tlumení využívá linearizovaný model magnetického ložiska. Pro řízení je navržen PID regulátor. V závěru je provedeno porovnání tlumeného a netlumeného modelu., The master’s thesis deals with building mechatronics model of machine tool head delivered by company TOSHULIN,a.s. for purpose of damping vibration. Mechanical part of the model is based on modeling of system of flexible bodies. Components are modeled in FEM program ANSYS and subsequently reduced using Craig-Bampton method. The system of flexible bo-dies is created in MBS program ADAMS. Model is linearized and subsequently reduced. As a element of active damping is used linearized model of magnetic bearing. For control is desig-ned PID controller. The comparison of damped and undamped model is conducted in the end.

Tato diplomová práce se zabývá návrhem hybridního magnetického ložiska. Jedná se o rozšíření problematiky běžných ložisek ve vysokootáčkových motorech. Práce je rozdělena do tří částí, kde se první část zabývá obecnou teorií magnetických ložisek. Druhá část se zabývá matematickým popisem ložiska. Třetí část se zabývá návrhem specifického hybridního magnetického ložiska. Návrh je proveden pro motor, pro který již bylo ložisko navrženo. Jedná se o motor o 45000ot/ min a výkonem 12kW. Cílem tohoto návrhu je vytvořit hybridní magnetické ložisko s magnety pro vytvoření stálého magnetického pole a cívkami pro regulaci sil ke stabilizaci rotoru a omezení vibrací. Praktický návrh zahrnuje matematický výpočet v programu MATLAB a počítačovou simulaci založenou na metodě konečných prvků v programu ANSYS Maxwell., The thesis deals with the design of a hybrid magnetic bearing. This is an extension of the issue of common bearings in high-speed motors. The work is divided into three parts. A general theory of magnetic bearings is described in the first part. The second part deals with the mathematical description of the bearing. A proposal of specific hybrid magnetic bearing is described in the third part. The bearing for the motor was already designed. It is a 45000rpm motor with a power output of 12 kW. This thesis aims to create a design of hybrid magnetic bearing with magnets to create a permanent magnetic field and coils to regulate forces to stabilize the rotor and limit vibrations. The practical design includes mathematical calculation in Matlab and computer simulation based on the finite element method in ANSYS Maxwell.

Diplomová práce se zabývá vytvářením mechatronického modelu hlavy obráběcího stroje dodané firmou TOSHULIN,a.s. za účelem tlumení vibrací. Mechanická část modelu je zalo-žena na modelování soustavy poddajných těles. Součástky jsou modelovány v MKP programu ANSYS a následně redukovány pomocí Craig-Bamptonovy metody. Soustava pružných těles je vytvářena v MBS programu ADAMS. Model je linearizován a následně redukován. Jako prvek aktivního tlumení využívá linearizovaný model magnetického ložiska. Pro řízení je navržen PID regulátor. V závěru je provedeno porovnání tlumeného a netlumeného modelu., The master’s thesis deals with building mechatronics model of machine tool head delivered by company TOSHULIN,a.s. for purpose of damping vibration. Mechanical part of the model is based on modeling of system of flexible bodies. Components are modeled in FEM program ANSYS and subsequently reduced using Craig-Bampton method. The system of flexible bo-dies is created in MBS program ADAMS. Model is linearized and subsequently reduced. As a element of active damping is used linearized model of magnetic bearing. For control is desig-ned PID controller. The comparison of damped and undamped model is conducted in the end.

Diplomová práce je zaměřena na literární rešerši a popis magnetických ložisek za účelem návrhu standu pro demonstraci magnetické levitace. Simulovaný model je vytvořen za pomocí metody konečných prvků. Dále se zabývá výhodami a nevýhodami spolu s porovnáním s klasickými ložisky v pohonech. Je zde diskutován analytický návrh, jež je zjednodušený a zanedbává několik parazitních jevů. Tyto analýzy jsou následně diskutovány. Hlavní část návrhu a postupu výpočtů je pro 8-pólové heteropolární radiální aktivní magnetické ložisko. Výsledek návrhu je následně uplatněn na realizaci demonstrátoru., The master thesis is focused on literature research and description of magnetic bearings in order to create a design model of a stand for demonstration of magnetic levitation. The simulated model is developed using the finite element method. It also discusses the advantages and disadvantages along with a comparison with conventional bearings in drives. Analytical design is discussed here, which is also simplified and neglects several parasitic effects. These analyses are then discussed. The main part of thesis containe design and calculation for an 8-pole active radial heteropolar magnetic bearing. The result of the design is then applied to the realization of the demonstrator.

Požadavky vysokorychlostních aplikací společně se snahou snížit spotřebu elektrické energie vedou k návrhům nových typů ložisek. V posledních desetiletích bylo hledáno ložisko, které by dosáhlo pasivní levitace použitím běžných materiálů při pokojové teplotě. To vedlo k vývoji elektrodynamického ložiska, které pracuje na principu vířivých proudů. V současné sobě ještě není elektrodynamické ložisko dostatečně prozkoumáno a jsou potřeba další výzkumy. Cílem práce je nejprve teoretický popis moderních magnetických ložisek, zjednodušená analýza elektrodynamického ložiska a návrh konkrétního ložiska podle zvolených parametrů. Tato konstrukce bude následně simulována konečně prvkovou metodou pro ověření a posouzení jeho vlastností., High speed applications demands with a need for lower energy consumption lead to designing new types of bearings. In the last decades magnetic bearing, which would be able to obtain passive stable levitation using regular materials at room temperature, has been searched. This has lead to development of electrodynamic bearing based on eddy currents principle. Currently the electrodynamic bearings are still not fully explored and further research is needed. The aim of the work is to describe the theory about modern magnetic bearing, analysis and design of electrodynamic bearing according to given parameters. The finite element method is used for further analysis and evaluate behaviour of its properties.