Pole Configuration Research Articles

On the State Space and Dynamics Selection in Linear Stochastic Models: A Spectral Factorization Approach

Matrix spectral factorization is traditionally described as finding spectral factors having a fixed analytic pole configuration. The classification of spectral factors then involves studying the solutions of a certain algebraic Riccati equation, which parametrizes their zero structure. The pole structure of the spectral factors can also be parametrized in terms of solutions of another Riccati equation. We study these two Riccati equations and describe how they can be combined for the construction of general spectral factors, which involve both zero and pole flipping on an arbitrary reference spectral factor.

Improved multipolar Poincaré–Hardy inequalities on Cartan–Hadamard manifolds

We prove a family of improved multipolar Poincare–Hardy inequalities on Cartan–Hadamard manifolds. For suitable configurations of poles, these inequalities yield an improved multipolar Hardy inequality and an improved multipolar Poincare inequality such that the critical unipolar singular mass is reached at any pole.

Enhanced catalytic performance by multi-field coupling in KNbO3 nanostructures: Piezo-photocatalytic and ferro-photoelectrochemical effects

The coupling between piezo-/ferroelectricity and photoexcitation in semiconductors creates unique opportunities to enhance the photocatalytic and photoelectrochemical (PEC) performance. It is important to develop desirable piezo-/ferroelectric nanostructures to realize the full potential of polarization-modulated built-in electric fields that can effectively separate excited electron/hole pairs. In this work, taking KNbO3 as a representative material, we show that two-dimensional nanosheets exhibit greatly improved piezo-photocatalytic degradation efficiency for organic dyes compared to that of nanocubes. In addition, effective tuning of the PEC water splitting property by manipulating the ferroelectric polarization was observed in these KNbO3 nanostructures, demonstrating versatile and tuneable devices for solar energy conversion. By changing the poling configuration, a significant photocurrent density enhancement of 55% was achieved for KNbO3 nanosheets, which is much greater than the 25% enhancement observed for the nanocube counterparts. These results could be attributed to the larger piezo-/ferroelectric response in the nanosheets as determined by piezoresponse force microscopy analysis and piezoelectric potential simulation based on the finite element method. Our findings may provide insights into strategies for designing highly efficient piezo-/ferroelectric nanomaterials for solar energy conversion.

Distributed fault estimation design of interconnected systems with external disturbances

In this study, a new distributed fault estimation observer (DFEO) design method is proposed based on unknown input observer (UIO) for interconnected systems with external disturbances. The coupling terms among interconnected subsystems are utilised to construct DFEO. At the same time, according to the characteristics of UIO, external interference is completely decoupled to improve the robustness of fault estimation. Furthermore, the authors propose a multi-constraint design with robust H ∞ and regional pole configurations to analyse and design gain matrices of DFEO, which can be calculated using linear matrix inequalities. Furthermore, asymptotic estimation of sensor faults is discussed with the help of DFEO. Finally, a simulation of the interconnected system is provided to illustrate the effectiveness of the proposed technique.

Compact generation of a two-photon multipath Dicke state from a single χ(2) nonlinear photonic crystal.

Multipartite quantum entanglement is a powerful resource for enriching the functionality of quantum computation and quantum communication. In this Letter, we propose a new method to generate a two-photon multipath Dicke state with concurrent spontaneous parametric downconversion processes from a single periodically poled nonlinear photonic crystal. We design the poling structure to produce a three-path Dicke state where three quasi-phase-matching conditions are fulfilled simultaneously by a hybrid one- and two-dimensionally poled nonlinear photonic crystal. We use genuine multipartite entanglement concurrence to quantify the entanglement of the Dicke state. Using a more complicated poling configuration like multiple-periodically poled two-dimensional nonlinear photonic crystal, we can also produce four-path, five-path, or multipath Dicke states by a single crystal. The multiple-periodically poled two-dimensional nonlinear photonic crystal provides a new method, to the best of our knowledge, for the integrated generation of multipartite quantum light sources.

Mutually Coupled Switched Reluctance Motor: Fundamentals, Control, Modeling, State of the Art Review and Future Trends

Switched reluctance motor (SRM) is gaining more interest in the last decades due to its simple and robust structure. SRMs are classified into conventional SRMs (CSRMs) and mutually coupled SRMs (MCSRMs). CSRMs are based on single-phase excitation and torque is generated by the variation of self-inductance with rotor position. MCSRMs are based on multi-phase excitation and torque is produced by the rate of change of both self- and mutual inductances. MCSRM has the advantages of using the standard voltage source inverter at balanced current operation, when the sum of the phase currents is zero, while CSRM requires an asymmetrical converter. This paper presents the state-of-the-art review of MCSRMs, including operating concept, winding, and pole configurations, control methods by using different current waveforms, performance comparison of MCSRM configurations, modeling methods, and future work for improving MCSRM performance.

(INVITED) Optimized optical fiber poling configurations

The creation of an effective second order nonlinearity via the process of thermal poling in materials such as glasses, which naturally lack any second order susceptibility, has been known since the early 1990s. In this review, we present a historical overview via an introduction presenting early evidence of second order nonlinear effects in glass to explain the working principles of the thermal poling technique. An overview is then given to the transfer of the technique from bulk materials to optical fibers. Different configurations of poling are presented and compared, namely the conventional anode-cathode set-up, the development of the cathode-less process and most recently, the induction poling technique, which allows for poling fibers without any physical contact between the embedded electrodes and the high voltage supply. 2D-numerical models of the induction poling technique are later presented. An overview is also given of the different solutions for embedding electrodes inside the cladding holes of the fiber. Apart from solid electrodes, the more recent results have been presented about the adoption of liquid electrodes, both metallic and aqueous. For the first time silica optical fibers have been thermally poled using tap water as electrode. Both these two main results, namely induction poling and the liquid electrodes can allow to overcome some of the apparently intrinsic limits shown by the thermal poling technique so far, such as for example the length of the nonlinear devices and the complexity of the geometrical structure of microstructured optical fibres, both solid and PCF. Finally, we review the most recent outcomes and published applications of periodically poled silica fibers from our group, including high harmonic generation and phase sensitive amplification. All these promising results demonstrate that the way towards a full exploitation of the thermal poling technique for all-fiber nonlinear photonics is opening up many new vistas.

Synthesis of Fringing Magnetic Fields for Static Mass Analyzers of the Spectrographic Type

Static mass analyzers offer a unique potential opportunity to achieve 100% utilization of ions generated by a continuously operating ion source. However, to achieve this, it is necessary for the mass analyzer to operate in the spectrographic mode rather than in the spectrometric mode. It is known that the conventional Mattauch–Herzog scheme may operate in the spectrographic mode with double focusing (by both angle and energy) along the straight focal line but only in the first order. The usage of more complex optical solutions is prevented by the fringing fields of static magnets, which destroy the exact spectrographic mode of the instrument operation. It is shown in the presented study that by using the principle of the similarity of trajectories in Euler-homogeneous fields one can purposefully synthesize asymmetric fringing magnetic fields of a particular type, which keep the spectrographic mode and the straightness of the focus line for static mass analyzers. Such fringing fields and the corresponding fringing configurations of magnetic poles and screens can become a basis for static mass spectrographs of a new type with high optical characteristics.

Review of Switched Reluctance Motor Control for Acoustic Noise and Vibration Reduction

Switched Reluctance Motor (SRM) is one of the candidates for substituting permanent magnet motor in Hybrid Electric Vehicle (HEV) application. Compared to permanent magnet motor, SRM is relatively low cost, robust, high reliability, and possible for high-temperature operation because of the absence of permanent magnet. One significant problem in SRM is the high acoustic noise and vibration. The vibration in SRM is caused by the radial forces acting at the stator teeth. Because of the saliency pole configuration in SRM, vibration is prominent. Many studies tried to reduce acoustic noise and vibration in SRM. In this paper, several controls for acoustic noise and vibration reduction are shown. The acoustic noise and vibration reduction from the experiment are also compared in each method.

A novel serial structure repetitive control strategy for shunt active power filter

PurposeThe purpose of this paper is to propose a novel serial structure repetitive control scheme for shunt active power filter (SAPF) to improve the steady-state accuracy and dynamic performance of SAPF. The novelty of this scheme lies in the reconfiguration of the pole of repetitive control internal model, so that the dynamic response of the repetitive control is improved greatly.Design/methodology/approachBy analyzing the mathematical model of repetitive control, the repetitive control delay can reduce by giving up the needless poles of the internal model, and the general mk + i repetitive control can be designed through the pole configuration method. The controller can track a set of specific order harmonics.FindingsThe experimental results are coincident with the theoretical analyses, which prove the effectiveness of the proposed method on harmonic suppression and great performance in dynamic response.Practical implicationsAn APF prototype has been designed with the serial structure repetitive control proposed in this paper, and it can successfully eliminate the harmonics current of nonlinear load with faster dynamic response. Moreover, the proposed controller can be applied to any three-phase system for fast dynamic response and high tracking accuracy.Originality/valueIn this paper, the mathematical model of the repetitive control for specific set of harmonica is developed. A novel serial structure repetitive control is designed, so that the SAPF can eliminate the fundamental reactive current and specific order harmonics and speed up the dynamic response of the repetitive control.

Closed-Form Solutions Using Offset Angle for Winding Configurations of Flux-Switching Permanent Magnet Machines

This paper presents a novel perspective to understand different winding configurations of flux-switching permanent magnet (FSPM) machines. A simple analytical method is used for the calculation of total offset angle of flux linkages by taking into account an offset angle of stator slot and rotor poles. The closed-form solution is presented to find the sequence of phase windings. The 12-slot/10-pole and 12-slot/13-pole FSPM machines are conceptually segregated into two sets of 6-slot/10-pole and 6-slot/13-pole machines, respectively. This is used to address even harmonic elimination and winding configuration properties in even and odd number of rotor pole configurations. Finite element analysis and experimental results verify the concept.

The functional outcome of sacral nerve stimulation for faecal incontinence can be improved by using lead model 3889 and a standardized implantation technique.

Sacral nerve stimulation has been recognized as an effective treatment option for faecal incontinence when conservative therapy has failed. Refinement of the procedural technique and the use of a curved stylet may improve the functional outcome. Our aim was to explore the relationship between lead model, functional outcome, stimulation amplitude and the need for extra visits during the first year of follow-up. Patient data from May 2009 to February 2017, which were prospectively collected in a local database, were extracted and analysed for differences between lead model and improvement in incontinence scores, stimulation amplitude and the need for additional visits during the first year of follow-up. A foramen lead model 3093(straight stylet) was used in 134 patients and lead model 3889(curved stylet) was used in 40 patients. There were no differences in baseline characteristics or incontinence scores. Comparing results between the two lead models we found that the improvement (delta value) in the Wexner score at 6months' follow-up (P=0.05) and the St Mark's score at 12months' follow-up (P=0.02) was greater in patients implanted with lead model 3889(curved stylet) compared with patients implanted with lead model 3093(straight stylet). Patients implanted with lead model 3889 (curved stylet) were less likely to have to alter the stimulation amplitude or pole configuration during the first year of follow-up (P=0.04). No difference was found for stimulation amplitude (P=0.170) or the need for additional visits (P=0.663). Lead model 3889 (curved stylet) improves functional results compared with lead model 3093 (straight stylet) during the first year of follow-up. Lead model 3889 (curved stylet) reduces the need for reprogramming but has no influence on stimulation amplitude or the number of additional visits required.

Development and Investigation on Segmented-Stator Hybrid-Excitation Switched Reluctance Machines With Different Rotor Pole Numbers

In order to improve the performances of switched reluctance machines (SRMs), such as torque production and power density, combining segmented structure and hybrid-excitation is a proper and useful method. This paper develops a kind of segmented-stator hybrid-excitation SRMs (SS-HESRMs) assisted with permanent magnets (PMs) and investigates on them with different rotor pole numbers. To evaluate the effects of different rotor topologies, the static magnetic characteristics and dynamic performances of two SS-HESRMs with 12/10 and 12/8 poles are briefly presented. Moreover, both SS-HESRMs are compared with two segmented-stator SRMs (SS-SRMs) which have the same basic structure and stator/rotor pole combinations but without PMs. The results reveal that SS-HESRMs produce higher electromagnetic torque than SS-SRMs with the same stator/rotor pole configuration. The 12/10 SS-HESRM exhibits better characteristics, such as higher dynamic average torque, lower torque ripple, and higher power/torque density, than the 12/8 SS-HESRM at low-speed operation. While at high speed, the 12/8 SS-HESRM exhibits better characteristics than 12/10 SS-HESRM. The 12/10 SS-HESRM has stronger starting capability but lower steady-state speed under the same starting condition. Finally, a 12/10 SS-HESRM and a 12/8 SS-HESRM with the same structure and size are prototyped and tested to confirm the predictions.

Review and synthesis of research investigating golden eagle electrocutions

ABSTRACTGolden eagle (Aquila chrysaetos) electrocution on power poles is a global conservation problem with an estimated 504 eagles electrocuted annually in North America alone. Despite widespread use of mitigation techniques to retrofit existing poles and to build new poles to avian‐friendly standards, electrocution remains a leading anthropogenic cause of death for the golden eagle. To assist electric utilities, wildlife managers, and the public in understanding eagle electrocution risk, we reviewed and synthesized risk factors and mitigation techniques from published literature from 1940 to 2016. Eagles have 8 electrocution risk factors: pole design, eagle age, morphology, land cover and topography, prey availability, season, weather, and behavior. Pole configuration was the most frequently identified electrocution risk factor and electrocution incidents were most often associated with distribution level (<69 kV) equipment poles. Age was the second most frequently identified risk factor, with juvenile eagles electrocuted at approximately twice the rate of subadults or adults. Risk was also associated with large body size, high‐quality habitat, high prey density, winter dispersal, inclement weather, and intraspecific interactions. Risk modeling based on these factors may assist electric utilities and other stakeholders in identification of high‐risk poles at the regional scale. High‐risk poles need prioritization for retrofitting by electric utilities. Compensatory mitigation funding becoming available through eagle take permitting may be useful in offsetting costs to utilities. Electrocution mitigation efforts strategized by region to target high‐risk poles could result in substantial reductions of golden eagle annual mortalities. © 2018 The Wildlife Society.

Development of 3-DOF active controlled magnetic suspension system with common magnetic pole.

A compact active three-degree-of-freedom magnetic suspension system is fabricated which has a new configuration of magnetic poles. The fabricated magnetic suspension system has a differential structure consisting of an upper and a lower electromagnets. The electromagnet consists of four poles with coils and a single common pole whose opposite plane of the floator has a permanent magnet to achieve zero power control. Modal control is applied because local zero power control may make the whole system unstable when the number of control channel are larger than the number of freedom of motion to be controlled. The system parameters of each mode are identified experimentally to design the modal control system. The characteristics of the fabricated magnetic suspension system are studied experimentally.

Three-Dimensional Evaluation of Posterior Pole and Optic Nerve Head in Myopes with Glaucoma

The degree of myopia is represented by a global index, such as refractive error or axial length. However, the progression of myopia mainly develops in the posterior eyeball. Therefore, it is reasonable to assume that the evaluation of myopia should be confined to the posterior segment, where most of the growth and lengthening occurs. Swept source optical coherence tomography software can reconstruct the scans to the coronal view of the posterior pole, which provides additional anterior-posterior depth (z axis in the Cartesian coordinates) that is not provided with the common fundus photograph. We deduced that the parameter of deepest point of the eyeball (DPE) as a surrogate for posterior pole configuration. Between myopes with and without normal tension glaucoma (NTG) with similar axial length, myopes with NTG had deeper and more distant location of the DPE from the optic disc. The difference of the DPE position between the myopes with and without NTG may have implications for the larger optic disc tilt and torsion characteristic of myopes with NTG. Furthermore, these data suggest that myopes with NTG go through excessive posterior scleral remodeling, which may result in vulnerable optic nerve head.

Study of The Electric Field Between Horizontal and Vertical Configuration Pole under 150 KV High Voltage Transmission Line (SUTT 150 KV)

Distribution of electrical energy from a plant to a substation or from a substation to other substations usually uses a transmission line. In Bali, type of transmission line that is usually implemented is SUTT 150 kV. The magnitude of the applied voltage is an attempt to reduce power loss for long distance distribution. However, distributing electrical energy with increasing stress affects the increase of electric field around the transmission line. The negative impact of electricity distribution has been an environmental problem for PT. PLN (Persero), especially where there is conversion from an open area to be a residential. This problem has been the main reason for conducting this research. IRPA / INIRC recommendation states that exposure time is not limited to the electric field effect in work environment and public area including a residential area at frequency of 50/60 Hz is 5 kV/m. This recommendation is in accordance with SNI 04-6950-2003, on Threshold Limit Values ??Electric Field under SUTT and high-voltage wires. The first problem of this research is how large the intensity of the electric field between two poles of SUTT 150 kV with vertical and horizontal constructions which are built side by side? The second problem is what the characteristic of the electric field intensity between the two poles which are built side by side? From the analysis, it can be seen that the intensity of the electric field that occurs between the conductor of the vertical and horizontal pole configurations are still below the IRPA/INIRC and SNI 04-6950-2003 recommendation i.e. 1 up to 1.5 kV/m and at a distance of 18 meters to 25 meters there is an interaction of electric field intensity that occurs at these two configurations.

Molecular dynamics study of structural reorganization by electro-thermal poling in sodium diborate glass

This work explores by molecular dynamics simulation the basic mechanisms and pathways that pertain to the induced optical nonlinearity in an ionic oxide glass due to electro-thermal poling. To the best of our knowledge, this is the first time where the kinetics combining the ion migration and the structural rearrangements is studied by using atomistic simulation. Most of the models published so far deal mainly with the charge transport effects, with no information provided on the kinetics of structural reorganization. To this aim, a simple borate glass doped with sodium cations was employed. Notwithstanding the small size of the specimen, due to computer time limitations, we were able to identify most of the experimental trends observed in different glass systems and under different poling conditions and configurations. They include the conversion of negatively charged structural units into neutral ones in the charge depletion region, a process reducing the excess negative charge after the migration of the mobile cations to the cathode, and the increased polymerization of the network close to the anodic surface. Taking into account the restrictions of our model, we also showed a mechanism for the generation of free oxygen species, due to the partial polarization of the Boron-Non-bridging oxygen (B-NBO) bonds along the embedded internal Direct Current (DC) electric field and their subsequent elongation and weakening.

Design of a Dual-Stator Superconducting Permanent Magnet Wind Power Generator With Different Rotor Configuration

The current capacity of superconducting materials is far larger than that of copper. This paper utilizes MgB 2 wires as stator armature windings to obtain a higher output power capacity and presents the electromagnetic design of a direct drive dual-stator superconducting permanent magnet (PM) wind power generator of several megawatts. Considering the irreversible demagnetization in PM materials caused by the huge stator current, several new rotor pole configurations are presented. The features of each configuration are discussed, and the finite element method results show that the output power capacity of the proposed generator can be raised by 8% because the stator current can be larger for the generator with new rotor configurations under the restriction of demagnetization.

Parameter adaptation of simplified switched reluctance motor model using Newton and Gauss-Newton signal fitting methods

PurposeThe paper is concerned about parameter adaptation of a novel, simplified and nonlinear switched reluctance motor (SRM) model. The purpose of the presented on-line procedure is to give an opportunity to set the model parameters’ values to obtain a relatively good convergence with the real control object. This is important when a reference model is used for control (e.g. optimal) or object state classification (e.g. fault detection) purposes. The more convergent the real object model is, the better operation quality may be expected.Design/methodology/approachIn the paper, a 12/8 pole’s SRM as a control object is analyzed. The model equations were verified experimentally by comparing phase current model estimations with reference (measured) ones at different operational points. Differential equations of motor winding currents were chosen as an approximation function in the fitting (parameter adaptation) process using the Newton and Gauss–Newton methods. The structure of the adaptation system is presented along with the implementation in simulation environment.FindingsIt was confirmed in the simulation tests that Newton and Gauss–Newton methods of nonlinear model parameters’ adaptation may be used for the SRM. The introduced fitting structure is well suited for implementation in real-time, embedded systems. The proposed approximation function could be used in process as an expansion to Jacobian and Hessian matrices. The χ2 (chi2) coefficient (commonly used to measure the quality of the signal fitting) reduced to a low value during the adaptation process. Another introduced quality coefficient shows that the Newton method is slightly better in scope of the entire adaptation process time; however, it needs more computational power.Research limitations/implicationsThe proposed structure and approximation function formula in the parameters’ adaptation system is appropriate for sinusoidal distribution of the motor phase inductance value along the rotor angle position. The inductance angular shape is an implication of the mechanical construction – with appropriate dimensions and materials used. In the presented case, the referenced model is a three-phase SRM in 12/8 poles configuration used as a main drive part of Maytag Neptune washing machine produced by Emerson Motors.Practical implicationsThe presented method of parameter adaptation for novel, simplified and nonlinear SRM model provides an opportunity for its use in embedded, real-time control systems. The convergent motor model, after the fitting procedure (when the estimations are close to the measurements from real object), may be used for solving many well-known control challenges such as detection of initial rotor position, sensorless control, optimal control, fault-tolerant control end in fault detection (FD) systems. The reference model may be used in FD in the way of deducing signals from the difference between the estimated and measured ones.Originality/valueThe paper proposed a new system of parameter adaptation for the evaluated nonlinear, simplified 12/8 poles SRM model. The relative simplicity of the proposed model equations provides the possibility of implementing an adaptation system in an embedded system that works in a real-time regime. A Two adaptation methods – Newton and Gauss–Newton – have been compared. The obtained results shown that the Newton fitting method is better in the way of the used quality indicator, but it consumes more computational power.