Magnetic Flux Control Research Articles

Intelligent vector control for a novel mechatronic modeling of a 1.5MW variable speed WECS using the bicausality concept under a real wind flow: A Bond Graph Approach

Enhancing the dynamic behaviors of Wind Energy conversion Systems (WECS) based on a doubly fed induction machine (DFIG) is one of the most attractive challenging in the field of maximizing renewable energy's output power, improving its quality and ensuring its efficient grid integration. For this purpose, a novel mechatronic modelling of a 1.5 MW variable-speed WECS based on a doubly fed induction machine using the Bond graph Approach is proposed, and three robust control strategies are displayed to regulate: the DFIG's active and reactive powers for the networks side converter (NSC), maximizing the extracted power and controlling the pitch angle for the load area. The flux oriented vector control laws presented in this contribution are based upon the independent control of magnetic flux and the electromagnetic torque inside the DFIG machine. They are derived from the integrated model's Inverse Bond Graph (IBG). This robust control strategy based on the bicausality concept enabled us to elaborate the Vector Control model that relies on a Radial Basis Function RBF-VC to be trained online with an optimal dataset under some real wind profiles. The robustness and effectiveness of the proposed model and RBF-VC controller are verified. The simulation results were conducted to confirm the validity of the proposed technique. Hands-on experience is carried out by means of the 20-sim software package.

Physical simulation and computational modelling for validation of soft magnetic composite impeder performance

Induction tube welding systems utilize an internal magnetic flux controller (impeder) to improve process efficiency. Work has previously been done showing that soft magnetic composite (SMC) materials may be suitable to improve these systems. A test stand was devised for the physical simulation of SMC impeder performance for use in induction tube welding systems. Tests were run to determine the loading and cooling conditions in which an impeder core made of SMCs could survive. Additionally, 2D thermal simulations were run to determine the cooling system thresholds given a particular magnetic loading of the core. The goal of these tests was to expand the design envelopes in which impeder cores made of SMCs could survive and validate their use in induction tube welding systems.

Control of the Probe-Sample Interaction Force at the Piconewton Scale by a Magnetic Microprobe in Aqueous Solutions

This article describes the design and implementation of a control system that controls the probe-sample interaction force at the piconewton scale by manipulating a magnetic microprobe in aqueous solutions under a microscope. The control system has two functions, namely accurate force generation by magnetic flux control and precise control of the probe-sample interaction force. Magnetic flux control uses an improved six-input-six-output digital control law along with a disturbance estimator to achieve two control objectives. First, the magnetic flux at each pole tip of a previously developed hexapole electromagnetic actuator can be individually and precisely controlled at frequencies over 4 kHz, and the experimental results precisely followed the theoretical predictions based on the design. Second, together with the optimized flux allocation, the flux control system generates precise magnetic forces, making the six-input hexapole actuator behave like a decoupled three-axis force generator with a bandwidth of more than 4 kHz. Interaction force control compares the measured deformation of the sample with the expected deformation, updated in real time by a deformation predictor, to generate the magnetic force to control the interaction between the probe and the sample. Digital control laws, the estimator, and the predictor are all implemented using a high-speed Field Programmable Gate Array (FPGA) system. Experiments confirm that through mathematical modeling, digital control technology, high-speed electronics, and real-time computation, accurate three-dimensional force generation at the piconewton scale with high bandwidth and precise interaction force control with zero-mean random error, attributed to random thermal force and measurement noise, are achieved.

A Simplified Model Predictive Voltage Control for Three-Phase Four-Switch Inverter-Fed PMSM Drives With Capacitor Voltage Offset Suppression and Current Ripple Reduction

This article proposes a simplified model predictive voltage control (SMPVC) method without weighting factors for three-phase four-switch inverter-fed permanent magnet synchronous motor drives to suppress the capacitor voltage offset and reduce the current ripple. In this article, the control of electromagnetic torque and magnetic flux in the model predictive torque control is transformed into the control of the voltage vector, and the capacitor voltage offset is suppressed by injecting dc component obtained by an adaptive notch filter into the phase current. On the basis, the voltage vector is taken as the only control term in cost function without the weighting factors to suppress capacitor voltage offset, thus simplifying the calculation amount in cost function. Then the simplified voltage vector synthesis method is presented to synthesize the effective voltage vector to reduce the current ripple. Using the simple sector division, the switching sequence of the voltage vector can be determined quickly. The effectiveness of the proposed SMPVC method is validated by the simulation and experiment.

압축구조 개선을 통한 분로리액터의 소음 저감에 관한 연구

Recently, with the development of the city center around the substation, complaints about noise are increasing. Shunt reactors are a major source of noise in substations. To reduce the noise of the shunt reactor, research on the magnetic circuit and structural design for optimizing the compression distribution are important. In this paper, the magnetic flux distribution and compression distribution of the magnetic element were calculated using a finite element analysis program, and the reduction effect was analyzed by measuring the noise. Introducing a study that improved the distribution of magnetic flux by applying a magnetic flux control panel to the vibration caused by the magnetomotive force generated from the magnetic element, and reduced noise by changing the shape of the compression structure.

Ultra-Precise High-Speed Untethered Manipulation of Magnetic Scanning Microprobe in Aqueous Solutions

This article describes the design and development of an integrated system that renders ultra-precise and high-speed, untethered manipulation of a single magnetic scanning microprobe in aqueous solutions under a microscope. The system uses a six-input-three-output hexapole electromagnetic actuator to control the magnetic gradient force exerted on the probe and a three-dimensional vision-based motion tracking system to enable feedback control. The control system has three core functions that enables superior manipulation of the magnetic microprobe. The six-input-six-output closed-loop magnetic flux control significantly suppresses the effect of magnetic hysteresis and greatly increases the bandwidth of magnetic flux generation. The optimal flux allocation solves four issues in multipole magnetic force generation: redundancy; coupling; nonlinearity; and position-dependency. The position-dependent discrete-time motion control law determines the required force for stabilization and tracking. These three core functions have been implemented using a high-speed field programmable gate array (FPGA) system. Experiments have verified that the use of digital control technology, high-speed electronics, mathematical modeling, and real-time computation has achieved superior manipulation of a single magnetic microprobe in aqueous solutions.

A Magnetically Controlled Current Transformer for Stable Energy Harvesting

The magnetically controlled current transformer (MCCT) is proposed to harvest stable energy from the magnetic field induced by the transmission-line fluctuating current. Compared with the conventional current transformer (CT), the advance of the proposed MCCT originates from the so-called constant magnetic flux control, which is achieved by connecting an electronic load on the secondary side of MCCT, and adjust the load impedance to make it equivalent to the corresponding resistive-capacitive impedance for magnetization or demagnetization. Furthermore, the working principle and the excitation characteristic of the MCCT system have been analyzed using the equivalent magnetic circuit and equivalent circuit methods. In addition, the details of the electronic load circuit and control system of the MCCT are presented in this paper, and the stability of the system is verified using logarithmic criterion and total harmonic current distortion (THDi) analysis. Finally, the co-simulation and experimental results show that MCCT can produce a stable output power of 13 W in the range of 50–500 A current fluctuations, demonstrating that the proposed magnetic energy harvester is capable of a high conversion efficiency and output stability.

Primena fazi logičkog kontrolera tipa 2 i kontrolera frakcionog reda za regulisanje brzine direktnog upravljanja momentom sile u indukcionom motoru

Introduction/purpose: Among excellent strategies available to control the torque of asynchronous motors, we distinguish direct torque control. This technique of control allows direct control of magnetic flux and electromagnetic torque without the need to decouple them. Also, direct torque control like each control strategy has some drawbacks, the major drawbacks of this technique being operation at a variable switching frequency and flux and electromagnetic ripples due to the use of hysteresis regulators. It worsens acoustic noise, especially at low speeds, as well as the control performances. Methods: To improve the performance of direct torque control especially at low speeds, the authors propose using fractional order PID in combination with type-2 fuzzy logic controllers to regulate the speed of an induction motor controlled by direct torque control. Results: The results obtained by the proposed regulators show the improvements made to the system. Conclusion: The proposed contribution can exert better control efforts.

FEATURES OF THE FIELD WEAKENING MODE IN А SWITCHED RELUCTANCE MACHINE

The magnetic field weakening mode of electric machines is used in modern drives to extend the drive operational speed range when the power supply voltage is limited. In conventional electric drives, a real or fictitious flux control loop, established in a vector control system by using coordinate and phase transformations of corresponding variables, is used for attenuating the motor magnetic flux. Switched reluctance machines have certain design advantages over conventional electric machines; they feature high reliability and wide control possibilities. However, to realize these possibilities, appropriate control outputs should be generated, the choice of which depends on the operational speed range. Another peculiarity of these machines is that there is no separate magnetic flux stabilization or control circuit. The article considers the specific features pertinent to the switched reluctance machine operation in various speed ranges for adequately taking them into account in control algorithms. The studies were carried out using the electric drive simulation model in the MATLAB Simulink environment. It is shown that during the electric drive operation at its limit mechanical characteristic in the low-speed zone under the speed variation conditions, the phase flux linkage average value can be considered almost unchanged. However, control of the average torque carried out by changing the current limitation level is performed at the magnetic flux weakening background. It has been determined that during operation in a high-speed zone at invariable phase switching positions with the speed growing in a natural manner (i.e., without applying control actions), there is an excessive decrease in the flux linkage average value, which leads to a dramatic drop in the phase average torque. This drop can be compensated by progressively shifting the phase engagement position in the leading direction.

Superconducting circuit architecture for digital-analog quantum computing

We propose a superconducting circuit architecture suitable for digital-analog quantum computing (DAQC) based on an enhanced NISQ family of nearest-neighbor interactions. DAQC makes a smart use of digital steps (single qubit rotations) and analog blocks (parametrized multiqubit operations) to outperform digital quantum computing algorithms. Our design comprises a chain of superconducting charge qubits coupled by superconducting quantum interference devices (SQUIDs). Using magnetic flux control, we can activate/deactivate exchange interactions, double excitation/de-excitations, and others. As a paradigmatic example, we present an efficient simulation of an ell times h fermion lattice (with 2<ell leq h), using only 2(2ell +1)^{2}+24 analog blocks. The proposed architecture design is feasible in current experimental setups for quantum computing with superconducting circuits, opening the door to useful quantum advantage with fewer resources.

Study of the two-rotor electric motor of a drive of vehicle drive wheels

In recent years, electric and hybrid vehicles have taken more and more attention due to their apparent advantages in saving fuel resources and reducing harmful emissions into the environment. Even though electric vehicles can solve the ecological problem, their operation is faced with a number of inconveniences associated with a limited driving distance from a single charge due to limited storage of energy from an independent power source and a lack of the required service and repair infrastructure. In hybrid and electric vehicles one of the main parameters is the curb weight, which affects energy consumption, vehicle speed, stability, controllability and maneuverability. In this regard, leading car manufacturers use parts with a low specific weight (non-metallic, aluminum alloys, etc.) in the design and also exclude some units from the design. Due to these technical solutions, the vehicle's operating is improved. One of the groups of parameters to be defined when designing a new electric vehicle is the parameters relating to the electric motor. The purpose of the article is determination of the mechanical characteristics of a two-rotor electric motor during magnetic flux control and assessment of the possibility of organizing the drive of the drive wheels of the vehicle. The electric motor has two mechanically independent outputs. For the study, an electrical equivalent diagram has been developed for the given two-rotor electric motor. A simulation model of the equivalent diagram has been built. Simulating the interaction processes of the rotors with the stator made it possible to obtain data for building the mechanical characteristics for each output of the electric motor. Analysis and processing of the mechanical characteristics data of the electric motors showed the conformity and the range of changes in the torque on each of the rotors when changing their slip and revolution, which are required when building algorithms for the operation of electric motor control systems as part of drives for various purposes. Analysis of the simulation results made it possible to assess the possibility of using the considered two-rotor electric motor for the drive of drive wheels in an electric and hybrid wheeled vehicle.

Deep Attenuation Use for Traction Motors of Mainline Electric Locomotives

Purpose. Given the need to improve the performance of modern mainline rolling stock, the authors analyze the possibility of using deeper regulation of attenuation. Methodology. The analysis of the operation of the thyristor-pulse converter of ER200 electric train is performed. It is established that in the acceleration mode at the limit traction characteristic it is necessary to consider two zones: the zone of constant value of traction force and the zone of constant power. A method for determining the minimum value of the attenuation coefficient for different types of DC and PC traction motors was proposed. The methods of theoretical research and analytical calculation of electrical circuits, theoretical foundations of electric traction, mathematical modeling of electrical and energy processes were used for the analysis. Findings. The complex of theoretical research and calculations allows confirming the technical possibility of deep attenuation use to regulate the speed regulation and obtain additional across-the-line positions for the rolling stock with DC and PC traction motors. The minimum attenuation coefficient value for different types of traction motors was determined. Originality. The methodology for determining the minimum value of the attenuation coefficient for traction motors of main electric locomotives in terms of using deeper magnetic flux control, replacing the use of experimental research data with theoretical studies. The essence of the studies is to form the required type of the limit traction characteristics by reducing the minimum permissible value of the excitation coefficient, which will reduce the electricity consumption. The research on determination of quantitative indicators of electricity consumption for the analysis of energy saving reserves on the main transport was further developed. Practical value. The results of theoretical research can be the basis for the modernization of main electric locomotives of direct and pulsating current with the systems of deep attenuation regulation. The research conducted will make it possible to create recommendations on designing the systems of magnetic flux regulation for traction engines with the improved technical and economic characteristics which are capable to increase the transport process efficiency on the main transport.

Performance Improvement of Reluctance Synchronous Motor Using Brain Emotional Learning Based Intelligent Controller

In this paper, intelligent control of a reluctance synchronous motor by an emotional controller, considering the effect of magnetic saturation on implementation, is analyzed; the maximum torque per ampere (MTPA) strategy is provided. According to the application of the proposed control scheme, the structure adequately performs the control of speed and magnetic flux of the reluctance synchronous motor drive. Additionally, the application of intelligent control based on an emotional learning system has provided adequate results to create a proper control process. The control function of a SynRM drive based on vector control in a rotor machine was compared with another based on emotional controllers and a PI controller regulated by genetic algorithms. The result of this comparison was the improvement of control functions by the controller based on the emotional controller. In addition, the MTPA based on search algorithms was well implemented in different situations. Due to its simplicity and independence from system parameters, the emotional controller can be considered as a potential operational method in the industry.

Information supply of the power control system of the synchronous generator of the autonomous wind unit

This paper deals with information supply of automatic maximum power control system of synchronous hybrid excited genera-tor for the autonomous wind unit. The power supply system based on an autonomous wind turbine consists of an electric generator, a battery charging controller, a battery pack and an inverter, which provides the required frequency and valueof the consumer's supply voltage.Three phase permanent magnet synchronous generator that have high technical and economic indicators are most widely used as electric generator of autonomous wind turbines.The main disadvantage of these generators is the lack of effective methods of magnetic flux control, limiting the optimization of the energy balance of the wind turbine.The paper discusses the application of synchronous generator with hybrid excitation system that consists of permanent magnets and additional field excitation winding lo-cated on the stator. Mathematical model of a hybrid excited synchronous generator is presented. Also,an output maximum power control system in a case of wind speed change by varying field excitation current is developed. Control system is developed based on concept of reverse task of dynamics in combination with minimization of local functionals of instantaneous values of energies.In the basics of the control method is put an idea of the reversibility of the Lyapunov direct method for the stability analysis.Obtained con-trol law provides thesystem stability inwhole, which allows solving control tasks of interrelated objects via mathematical models of local loops. Control law also provides low sensitiveness to parametric disturbances and gives dynamic decomposition of interrelated non linear system that ensures its practical implementation. The study of the proposed power control system based on parameters of hybrid excited synchronous generatorexperimental sample has been carried out. The graphs of transient process of armature power, voltage and current in a case of wind speed change from 3 to 8 m/s were obtained, as well as in a case of active resistance load change. The results of study showed high efficiency of power control of a wind turbine with hybrid excited synchronous generator.

Non-Newtonian fluid flow having fluid–particle interaction through a porous zone in a channel with permeable walls

Abstract The flow of Casson fluid streaming through a porous zone in a permeable channel with homogeneously distributed dust particles is studied. The flow is oscillatory and exposed to thermal radiation. With non-uniform temperature and velocity slip at the wall, the channel is put under transverse magnetic flux control. The variable separation approach is used to obtain the exact analytic solution for the flow fields of fluid and dust particles. Physical insights of collective effects of suction/injection, magnetic field, thermal radiation, and buoyance force on the fluid velocity, temperature, rate of heat transport and friction at the wall surface are examined and analysed graphically. Results reveal that surface friction increases on both channel plates as an injection on the hot plate rises.

Fast flux control of 3D transmon qubits using a magnetic hose

Fast magnetic flux control is a crucial ingredient for circuit quantum electrodynamics (cQED) systems. So far, it has been a challenge to implement this technology with the high coherence 3D cQED architecture. In this paper, we control the magnetic field inside a superconducting waveguide cavity using a magnetic hose, which allows flux control of 3D transmon qubits on time scales less than 100 ns while maintaining a cavity quality factor larger than 106. The magnetic hose is designed as an effective microwave filter to not compromise the energy relaxation time of the qubit. The magnetic hose is a promising tool for fast magnetic flux control in various platforms intended for quantum information processing and quantum optics.

Magnetic flux control in an urban distribution network based on load optimisation

This paper proposes a control method for eliminating direct current (DC) flux from the isolation transformer of a customer service device to avoid magnetic saturation. The method is characterised by injecting zero compensation voltage during a designed time. The period during which no compensation voltage is injected is minimised by adjusting the normal compensation time in the initial stage. For a customer service device, such as a dynamic voltage restorer, the reverse turn-off voltage will introduce extra initial flux. The calculation process based on a trigonometric function also takes into account the effects of the initial flux. The experimental results verify the proposed method to prevent DC flux to the isolation transformer.

Resonance inversion in a superconducting cavity coupled to artificial atoms and a microwave background

We demonstrate how heating of an environment can invert the line shape of a driven cavity. We consider a superconducting coplanar cavity coupled to multiple artificial atoms. The measured cavity transmission is characterized by Fano-type resonances with a shape that is continuously tunable by bias current through nearby (magnetic flux) control lines. In particular, the same dispersive shift of the microwave cavity can be observed as a peak or a dip. We find that this Fano-peak inversion is possible due to a tunable interference between a microwave transmission through a background, with reactive and dissipative properties, and through the cavity, affected by bias-current induced heating. The background transmission occurs due to crosstalk between the control and transmission lines. We show how such background can be accounted for by Jaynes-Cummings type models via modified boundary conditions between the cavity and transmission lines. We find generally that whereas resonance positions determine system energy levels, resonance shapes give information on system fluctuations and dissipation.

Compensation of Hysteresis in Hybrid Reluctance Actuator for High-Precision Motion

In hybrid reluctance actuators for high precision motion control, the magnetic hysteresis in the ferromagnetic stator and mover usually affects the precision. Therefore, this paper proposes magnetic flux estimation and control to compensate for the hysteresis. To measure the magnetic flux at various frequencies, the output signal of a search coil is combined with that of the current monitor of the employed current amplifier in a magnetic flux estimator. Finally, a magnetic flux controller is designed and implemented. For evaluation of the hysteresis compensation, the performance of the hybrid reluctance actuator is compared with both flux and current control. Experimental results show that flux control successfully compensates for some of the nonlinearities of the hybrid reluctance actuator, as the hysteresis is reduced by up to a factor 8.2 and the phase lag of the mover position is reduced by up to 6 deg in comparison with the case of current control.

Magnetic flux control laws in differential electric drive

This paper considers scheme options of the multimotor differential electric drive system. These schemes have competitive energy and weight-size parameters. The number of independent control commands exceed the number of controlled coordinates. Magnetic flux magnitude of the electric machine may be accepted as a control command. Methods of nonlinear programming synthesized the flux control laws in a multimotor differential electric drive system. The minimum weight-size characteristic of the electric power equipment was taken as an optimization criterion. Possibility of founded control laws approximation was shown by the simple piecewise linear equation. Speed control of the electric drive was changed only by one electric machine flux for each of the segments. Fluxes of other machines remained unchanged, equal to the nominal values. Additional losses did not exceed few percent in case of refusal from the exact control law in the area of small loads. Also, it was not observed in the rated area at all.