Nonlinear Inductance Research Articles

A New Efficient Rectifier Circuit Based on Nonlinear Inductance Impedance Conversion

The conventional capacitor filter bridge rectifier circuit has the characteristics which the input current is discontinuous, peaked and contains high-order harmonics. A new nonlinear inductance impedance transformation circuit is presented based on the the characteristics of general rectifier circuit in this paper. Before being used in capacitance filter of the general bridge rectifier and it ensures that when the power voltage is lower than that of rectifier the value of nonlinear resistance will vary with the voltage to check the dead area range for input current and decrease harmonics. It improves the character of power factor, and is important to energy saving.

Designed Analogue Black Hole Solitons in Josephson Transmission Lines

In the nonlinear LC circuit dual to the Toda (voltage) soliton, the current (shock-wave-type) solitons spatially modulate the velocity of the electromagnetic waves in the circuit through the nonlinear inductance, resulting in the creation of analogue black holes. The analogue black hole solitons are spontaneously formed, but their configuration could not be controlled so far. In this paper, the on-demand scheme to design the configuration of analogue black holes is presented by using solitons and antisolitons in the nonlinear LC circuit. In addition, a novel photon source using analogue Hawking radiation is also proposed.

Development of an Array of Kinetic Inductance Magnetometers (KIMs)

We describe optimization of a cryogenic magnetometer that uses nonlinear kinetic inductance in superconducting nanowires as the sensitive element instead of a superconducting quantum interference device (SQUID). The circuit design consists of a loop geometry with two nanowires in parallel, serving as the inductive section of a lumped LC resonator similar to a kinetic inductance detector (KID). This device takes advantage of the multiplexing capability of the KID, allowing for a natural frequency multiplexed readout. The Kinetic Inductance Magnetometer (KIM) is biased with a DC magnetic flux through the inductive loop. A perturbing signal will cause a flux change through the loop, and thus a change in the induced current, which alters the kinetic inductance of the nanowires, causing the resonant frequency of the KIM to shift. This technology has applications in astrophysics, material science, and the medical field for readout of Metallic Magnetic Calorimeters (MMCs), axion detection, and magnetoencephalography (MEG).

Electro-permanent magnetic weight release mechanism for buoyancy control of an autonomous well-logging tool

We present the design and test of a magnetic actuator that is used to hold and release a ballast and switch buoyancy of a miniaturized autonomous well-logging tool from negative to positive. The actuator makes use of a low coercivity aluminum-nickel-cobalt (AlNiCo) magnet paired with a high coercivity neodymium-iron-boron (NIB) magnet to create and cancel a magnetic pull force on a steel plate by changing the polarization direction of the former magnet. Brief current pulses sent through a solenoid wrapped around the AlNiCo magnet by charging and discharging a capacitor. The resulting resistor-inductor-capacitor (RLC) circuit is analyzed to understand the polarization process of the AlNiCo magnet and state change of the actuator’s pull force. Our numerical solution using a nonlinear inductor model and test results showed that the repolarization can be achieved in steps using a relatively small 0.1 mF capacitor thanks to stored remnant field at each step. This made it possible to save space and energy for the miniaturized autonomous logging tool. Effects of NIB and steel weight piece on the AlNiCo polarization are experimentally analyzed. Magnetic circuit geometry is optimized using finite element analysis to maximize the pull force on the weight. The actuator occupies less than 2 cm3 and provides more than 2 kg-f to carry a ballast that weighs about 60 grams.

Emergence of complex dynamic behaviours in the Chua's circuit with a nonlinear inductor

By considering a nonlinear inductor in the Chua's circuit, the dynamics of the circuit can be appreciated in a more generalised way and some neglected aspects of the realities of electronics are taken into consideration. In this work, the cubic and polynomial current-dependent models of the inductor are used. A systematic study is done with the help of tools such as bifurcation diagrams, Lyapunov spectrum and frequency power spectrum. The rich dynamics of the system reveal some complex behaviours and phenomena. Especially antimonotonicity, metastable chaos, coexistence of non-symmetric periodic orbits and chaotic attractors, phenomena that were not observed in the classical and the canonical Chua's circuit.

Emergence of complex dynamic behaviours in the Chua's circuit with a nonlinear inductor

Emergence of complex dynamic behaviours in the Chua's circuit with a nonlinear inductor

К общей теории анализа субгармонических колебаний в трехфазных феррорезонансных цепях и системах

The general theory for analysis of subharmonic oscillations at a frequency of ω/3 in three-phase ferroresonance circuits is presented. The occurrence and existence of ferroresonance oscillations at subharmonic frequencies in power transmission lines and power supply systems is highly undesirable, since they cause overvoltages at various frequencies. At the same time, there is an extensive class of nonlinear electrical circuits in which the excitation of autoparametric oscillations at the frequency of subharmonics forms the basis of phase-discrete frequency converting devices serving as secondary power sources. To study the regularities of excitation and maintaining of subharmonic oscillations at a frequency of ω/3 in three-phase ferroresonance circuits, theoretical and experimental studies of an equivalent model of a three-phase circuit with nonlinear inductance were carried out. A generalized nonlinear differential equation for a three-phase circuit with mixed connection of its elements is derived. The steady-state mode of subharmonic oscillations at a frequency of ω/3 is analyzed using the small parameter (averaging) method, which made it possible to determine their existence domains and circuit critical parameters. A mathematical model and algorithm for calculating autoparametric oscillations have been developed to study the subharmonic oscillation excitation processes at a frequency of ω/3 in three-phase ferroresonance circuits depending on the initial conditions, circuit parameters and input voltage. The theoretical study results have been confirmed experimentally.

Feasibility evaluation of new electric motors driven by intrinsic localized mode

Intrinsic localized mode (ILM) has been observed in various physical systems. In particular, electromagnetic ILM has been observed on an LC ladder circuit array. This paper focused on the electromagnetic ILM and aims to evaluate the feasibility of a new electric motor driven by the electromagnetic ILM numerically. First, we propose two types of nonlinear inductors with different geometries, and their magnetic saturation characteristics are clarified from the magnetic field analysis. Second, numerical simulations using the obtained parameters show that the moving velocity of a moving ILM varies with an initial voltage disturbance. Finally, we propose an inductor with permanent magnets placed on a surface of a rotor core, aiming to generate the electromagnetic ILM more efficiently. Numerical simulations show that the behavior of the moving ILM is affected by the rotational speed of the rotor.

Artificial Neural Network-Based Gain-Scheduled State Feedback Speed Controller for Synchronous Reluctance Motor

Abstract This paper focuses on designing a gain-scheduled (G-S) state feedback controller (SFC) for synchronous reluctance motor (SynRM) speed control with non-linear inductance characteristics. The augmented model of the drive with additional state variables is introduced to assure precise control of selected state variables (i.e. angular speed and d-axis current). Optimal, non-constant coefficients of the controller are calculated using a linear-quadratic optimisation method. Non-constant coefficients are approximated using an artificial neural network (ANN) to assure superior accuracy and relatively low usage of resources during implementation. To the best of our knowledge, this is the first time when ANN-based gain-scheduled state feedback controller (G-S SFC) is applied for speed control of SynRM. Based on numerous simulation tests, including a comparison with a signum-based SFC, it is shown that the proposed solution assures good dynamical behaviour of SynRM drive and robustness against q-axis inductance, the moment of inertia and viscous friction fluctuations.

Improved sensorless control scheme for PMSM based on high-frequency square-wave voltage injection considering non-linear change of inductance in D-Q axis

Aiming at the position sensorless control system of permanent magnet synchronous motor (PMSM), an improved high-frequency square wave (HFSW) signal injection scheme considering nonlinear inductance variation in d-q axis is proposed and implemented in this paper. Compared with the existing model, the modified scheme can take the dynamic variation of d-q axis inductance under different operation conditions into consideration by offsetting the resulting high-frequency incremental (HFI) current harmonic components, thus effectively suppressing the estimation error of the rotor position. The experimental results verify that the improved scheme proposed in this paper can not only improve the estimation accuracy of rotor position impaired by the non-linear variations of d-q axis inductance but also maintain the good steady-state and dynamic performance of traditional schemes.

Analysis of the influence of inductor saturation on the level of electromagnetic interference of DC/DC-converters

The results of the study on the effect of the design parameters of a nonlinear inductor on the level of electromagnetic interference generated by DC/DC converters are presented. The paper proposes models designed for the LTspice XVII environment, which allow investigating conducted interference spectra, efficiency and output voltage ripple of the converter using a nonlinear inductor model. The simulation results showed that the level of conducted interference is affected by the volume and material of the inductor core, as well as the presence of an air gap in the core. The results of measurements of conducted interference spectra at different values of the cross-sectional area of the inductor core of the DC/DC converter are presented. With the nominal cross-sectional area of the core, calculated taking into account converter output power, the study of the relationship between the level of conducted interference and the width of air gap in the inductor core is carried out. In the course of studies, using the Chan model, the influence of inductor core material on the level of interference generated by the DC/DC converter is analyzed. Analysis of the influence of the width of the air gap in the inductor core on the level of conducted interference is carried out. It is shown that air gap width should be selected taking into account inductor core material. Simulation results for a number of commonly used materials made it possible to determine the most effective one in terms of generated interference.The results obtained in the analysis of switching voltage converter operation, taking into account inductor nonlinearity, allow us to formulate recommendations to reduce the level of generated conducted interference by 4.5 to 6 dB due to the correct choice of inductor material and design parameters

Modelling and identification of switched reluctance machine inductance

ABSTRACT Identification of phase self-inductance is a central step in control and development of Switched Reluctance Machine (SRM) model because the voltage and torque equation are functions of the phase self-inductance. The SRM operates primarily in the saturation region because the power factor is lower in the linear region, which makes the SRM modelling difficult to achieve. The strong nonlinearity of this machine must be taken into consideration by appropriate identification of the inductance parameters. This paper presents a new method for analytical modelling and identification of nonlinear inductance at standstill tests. We have shown that our electrical model of SRM can be described by Hammerstein model as a typical nonlinear model with a specific structure. The proposed method differs substantially from the existing used to identify the inductance of SRM. The results of this analytical approach are compared with those obtained using magnetostatic finite element method and experimental measurement. The comparison results show good accuracy of the identified model.

Quasi-Two-Level PWM-Operated Modular Multilevel Converter With Nonlinear Branch Inductors

Quasi-two-level PWM operation of modular multilevel converters enables very low module capacitance even at low machine speeds and high torques while the current distortion is tolerable. In this article, the application of nonlinear inductors together with this operation mode is investigated to further decrease the module capacitances. The requirements for the inductors are analytically derived and the design of the nonlinear inductors using a stepped air gap is demonstrated. The feasibility and the advantages of quasi-two-level PWM operation with nonlinear inductors are validated using simulations and a laboratory prototype.

Nonlinear modeling and performance testing of high-power electromagnetic energy harvesting system for self-powering transmission line vibration deicing robot

This paper proposed the nonlinear modeling and a full-scale testing method for an electromagnetic energy harvester (EMEH) used to power-up a vibration de-icing robot used in power transmission line. The aim of the proposed work is to have an detailed analytical model of the EMEH on MATLAB environment which is capable of considering the EMEH ferromagnetic core material nonlinear characteristic in the design stage and can provide a fast and accurate analytical model with different design parameters for manufacturing. The nonlinear model is derived by considering Norton equivalent circuit of the EMEH with a nonlinear Norton equivalent inductance. With the nonlinear model design data, a prototype is manufactured and different performance tests such as the validation for the Norton equivalent circuit parameters, AC-DC conversion, and maximum power transfer from the EMEH using the discontinuously conducting DC-DC converters are conducted.

Analogue Hawking radiation from black hole solitons in quantum Josephson transmission lines

The nonlinear LC circuit dual to the Toda lattice (voltage) soliton is studied using the reductive perturbation method. It is found that the current flowing through the circuit obeys the defocusing modified Korteweg--de Vries equation with shock-wave-type (current) solitons. The current soliton spatially modulates the nonlinear inductance, equivalently the spatial modulations of electromagnetic wave velocity in the circuit, resulting in the generation of analogue black holes. Hawking radiation from the black holes is also discussed based on the tunneling models.

Dual Hysteresis Model of MR Dampers

This study concerns modeling the hysteretic behaviour of magnetorheological (MR) dampers. In general, hysteresis is one of key factors influencing the output of such actuators. So far more attention of various researchers has been paid to studying the combined hysteretic behaviour of MR actuators by observing the relationships between the output (force/torque) and the inputs (current, velocity, position). However, these devices feature two distinct hysteretic mechanisms: mechanical/hydraulic and magnetic. The mechanical hysteresis is of different nature than the magnetic hysteresis due to the properties of ferromagnetic materials forming the actuator's elec- tromagnet circuit, and these should be split in the modeling process. In the present study we separate the magnetic hysteresis from the mechanical/hydraulic one by investigating the magnetic flux vs exciting current relationship of a commercial flow-mode MR damper subjected to sinusoidal current loading and independently of the mechanical excitations. The resulting behaviour of the electromagnetic circuit is then examined using the nonlinear inductor approach with hysteresis. Total hysteresis is then modeled using a non-linear inductor model in combination with a phenomenological parametric Maxwell type model of the damper.

Hinge solitons in three-dimensional second-order topological insulators

Higher-order topological insulators have recently witnessed rapid progress in various fields ranging from condensed matter physics to electric circuits. A well-known higher-order state is the second-order topological insulator in three dimensions with gapless states localized on the hinges. A natural question in the context of nonlinearity is whether solitons can exist on the hinges in a second-order topological insulator. Here we theoretically demonstrate the existence of stable solitons localized on the hinges of a second-order topological insulator in three dimensions when nonlinearity is involved. By means of systematic numerical study, we find that the soliton has strong localization in real space and propagates along the hinge unidirectionally without changing its shape. We further construct an electric network to simulate the second-order topological insulator. When a nonlinear inductor is appropriately involved, we find that the system can support a bright soliton for the voltage distribution demonstrated by stable time evolution of a voltage pulse.

Unfolding Nonlinear Dynamics in Analogue Systems With Mem-Elements

The paper considers a relevant class of networks containing memristors and (possibly) nonlinear capacitors and inductors. The goal is to unfold the nonlinear dynamics of these networks by highlighting some main features that are potentially useful for real-time signal processing and in-memory computing. In particular, an analytic treatment is provided for dynamic phenomena as the presence of invariant manifolds, the coexistence of different regimes, complex dynamics and attractors and the phenomenon of bifurcations without parameters, i.e., bifurcations due to changing the initial conditions of the state variables for a fixed set of circuit parameters. The paper also addresses the issue of how to design pulse independent voltage or current sources to steer the network dynamics through different manifolds and attractors. Two relevant examples are worked out in details, namely, a variant of Chua's circuit with a memristor and a nonlinear capacitor and a relaxation oscillator with a memristor and a nonlinear inductor. In the latter example, the paper also studies the effect on manifolds and coexisting dynamics when real memristive devices are accounted for using a class of extended memristor models. The analysis is conducted by means of a recently developed technique named flux-charge analysis method (FCAM). Numerical simulations are presented to confirm the theoretic findings.

Computation-Efficient Solution to Open-Phase Fault Tolerant Control of Dual Three-Phase Interior PMSMs With Maximized Torque and Minimized Ripple

For dual three-phase interior permanent magnet synchronous machines (DT-IPMSMs), open-phase fault (OPF) can result in significant average torque reduction and harmonics in the output torque and speed, which prevent the machines from a reliable and safe operation. Indeed, these adverse effects are mainly due to significant harmonics in the stator currents caused by OPF. This article investigates fault-tolerant control (FTC) of DT-IPMSM under OPF and proposes a computation-efficient FTC solution to maximize the average torque and minimize the fault-induced torque and speed ripples. In the proposed FTC, the open-phase model is first derived, and optimal stator currents are then derived to achieve maximized average torque and minimized fault-induced torque harmonics. The computation efficiency enables the proposed solution, the capability of FTC, under both the steady-state and transient conditions. Moreover, the proposed FTC can eliminate the harmonic current components in the torque contributing frame and, thus, reduce the harmonic losses, and nonlinear inductance maps are employed to consider magnetic saturation. The proposed FTC is compared with existing methods and evaluated with experiments on a laboratory DT-IPMSM under various operating conditions.

Mitigation of Ground Leakage Current of Single-Phase PV Inverter Using Hybrid PWM With Soft Voltage Transition and Nonlinear Output Inductor

A single-phase transformerless full-bridge photovoltaic grid-tie inverter is presented. It utilizes 1) a virtual ground technique to mitigate ground leakage current, 2) a hybrid pulsewidth modulation (HPWM) scheme to profile the output current and prevent sudden changes in the common-mode voltage, and 3) a nonlinear output inductor to attenuate current ripple around zero crossings and minimize filter size. The HPWM is effectively the same as unipolar PWM (UPWM), but with soft voltage transition modulation introduced around the zero crossings. Apart from low switching losses, the output filter is implemented with a minimum number of components to achieve high attenuation of ripple current. By deriving the switching trajectory, a mathematical model is formulated, and the ground leakage current and the output current with the traditional UPWM and the proposed HPWM schemes are compared. The output current harmonics caused by the nonlinear output inductor is analyzed by the Volterra theory. A 340 W, 380 Vdc/110 V ac, 50 Hz prototype has been built and evaluated.