Additional Induction Research Articles

Ultra-high voltage gain achieved with quadratic DC/DC converter design

This work introduces a novel DC/DC converter with an incredibly high voltage gain, specifically designed for renewable energy generating systems. The proposed circuit features a coupled inductor integrated with a quadratic boost circuit and a voltage multiplier cell to achieve a substantial step-up in voltage gain. Ultra-high voltage gain, minimum reverse recovery in diodes, low voltage stress on switching devices, continuous input current, and a shared ground between the input source and output load are some of this topology’s key features. The coupled inductor design reduces power dissipation in magnetic components by distributing the high DC source current with an additional input inductor. Additionally, regenerative clamp circuits alleviate voltage stresses on power switches during simultaneous switching. Theoretical analysis covering the operating principle, steady-state behavior, and efficiency is discussed in detail. An evaluation of the suggested topology’s performance is conducted using a 250-W, 25-V/400-V lab prototype.

A Flyback Converter with a Simple Passive Circuit for Improving Power Efficiency

This paper proposes an effective method to improve the power efficiency of the flyback converter in the continuous conduction mode (CCM). The proposed converter uses a simple passive circuit to reduce the switching power losses. The current through the output diode can be shifted to a new branch where one diode, one inductor, and one auxiliary winding of the transformer are included. The output diode current can be reduced to zero for the zero-current switching of the output diode. The additional inductor is used to control the changing rate of the additional diode current to reduce the reverse-recovery current. Keeping the simplicity of the passive method, the proposed converter improves the power efficiency compared to the conventional converter. The circuit configuration and the operation principle are described. The design considerations are presented, including the simulation verification. The experimental results for a 45 W prototype are discussed to evaluate the performance of the proposed converter. The proposed converter has achieved a power efficiency of 93.5% for the rated load condition, improving the power efficiency. The applications of the proposed converter are also discussed for the future research directions.

A new high step-down soft-switched DC–DC converter based on coupled inductor

ABSTRACT This study introduces a new non-isolated DC–DC converter capable of achieving a high step-down conversion ratio. The design reduces switching losses through soft-switching, allowing switches to operate under Zero Voltage Switching (ZVS), which enhances efficiency. The converter employs a single coupled inductor without additional inductors in the power path, achieving low voltage gain and an extended duty cycle, resulting in reduced losses, lower costs, and optimal efficiency compared to similar topologies. Voltage stress on semiconductors is minimised by recycling leakage inductance energy to the output. The proposed converter achieves a greater step-down voltage gain per component compared to similar designs. Different operational modes and design aspects are examined. A prototype was constructed, and experimental results confirmed the theoretical analysis.

A Hybrid Beat Frequency Oscillation Suppression Strategy for DC Microgrids

In DC microgrids, parallel-connected power converters are commonly used to integrate distributed energy sources. However, interactions of power switching noises among these power converters could lead to large low-frequency beat frequency oscillations under certain conditions, which degrades system performance and reliability, especially for DC microgrids with parallel connected Boost converters. In this research, the output impedance model for multiple parallel-connected Boost converters is developed for beat frequency oscillation analysis, and then a hybrid method is proposed to address this issue. The proposed method includes separated switching frequency channels and additional line inductors. Experimental results validate the effectiveness of the proposed method.

Solving dynamic electric circuit with nonlinear hysteretic inductor using harmonics interpolation method

SummaryThe aim of this paper is to present a methodology for solving а dynamic electric circuit with nonlinear hysteretic inductor without the use of hysteresis model or equivalent circuits. A consideration of nonlinear and hysteretic behaviour of the magnetic core under quasistatic conditions is based on applying harmonics interpolation method (HIM) to the measured magnetising field strength waveforms. A dynamic behaviour of the magnetic core is considered through the application of the statistical theory of losses (STL). A considered electric circuit consists of AC voltage source connected in series with shunt resistor, additional linear resistor and inductor, as well as a nonlinear hysteretic inductor. The solution for electric current of the circuit is obtained by solving equation derived from Kirchhoff's laws through a series of successive iterations. Coupling of electric and magnetic part of the circuit is obtained from fundamental laws of electromagnetism. Methodology is validated for four cases of the considered electric circuit — without additional elements, with one additional or both additional elements, for sinusoidal voltage source amplitudes of 2, 4, 6, 8 and 9 V and frequency of 50 Hz. Validation is repeated for frequencies of 100, 200 and 300 Hz while keeping the ratio of the amplitude to frequency constant. Detailed theoretical approach and methodology, comparisons between measured and calculated results, as well as adequate discussion are presented.

Analysis of Reachable and Positive Electrical Circuits Modelled by differential Algebraic System

This research paper undertakes an exploration of novel concepts within the domain of electrical circuits modeled by matrices. The study is centered around circuits encompassing elements such as resistances, coils, and voltage sources, with a specific focus on elucidating aspects of positivity and reachability. A distinctive approach is employed through the introduction of additional inductors, aimed at enhancing the circuit’s functionality. Employing mathematical analysis, this research endeavor advances an extensive comprehension of these circuits, shedding light on their behavior even when subject to specific constraints. As a consequence, this inquiry contributes to the revelation of noteworthy insights about the operational dynamics of circuits.

Modified EPS Control and Topology Modification for Two-Stage Bidirectional AC-DC Converter for V2G Applications

Abstract For the two-stage bidirectional AC-DC converter applied to vehicle-to-grid (V2G), this paper studies the modulation strategy and the topology of the dual active bridge (DAB) converter in the DC-DC stage. Aiming at the problem of large circulating current due to the fixed internal phase shift under the traditional extended phase shift (EPS) control, this paper modified the EPS modulation strategy by deciding whether the internal phase shift is generated by the primary or secondary side based on the voltage gain, which realizes the high-efficiency power transfer under wide voltage gain. To realize the full load range zero voltage switching (ZVS) with junction capacitors taken into account, it is proposed to parallel an additional auxiliary inductor between the bridge arms of the DAB converter, and the operating mechanism and the improved effect are analyzed in detail. Finally, a simulation circuit was built using PSIM software to verify the correctness.

Cellulases production optimization and inductors evaluation in pretreated plantain rachis by Penicillium oxalicum

AbstractPretreated lignocellulosic residues are suitable substrates for cellulases production by filamentous fungi. In the current work, plantain rachis was pretreated with sequential acid and alkali and then used as the main carbon source for cellulases production. First, a full 23 factorial design and response surface methodology (RSM), based on central composite rotatable design (CCRD), were carried out to cellulases production media optimization from plantain rachis by Penicillium oxalicum. The cellulases production was evaluated in flasks and bioreactor scale; in parallel, the addition of possible cellulases inductors was evaluated in flasks: molasses, beer bran, oat bran, and wheat bran. Results from statistical analyses with a level of confidence of 95% demonstrated that the concentration of ammonium sulfate must be kept at 1.625 g/L. The optimum urea and yeast extract concentrations were 0.560 g/L and 0.250 g/L, respectively. Cellulases volumetric productivities were higher in instrumented bioreactor than in flasks: 78.03% for exoglucanase, 10.87% for endoglucanase, 1.58% for β‐glucosidase, and 44.36% for FPU. Therefore, P. oxalicum was able to produce cellulases from plantain rachis in flasks and bioreactor, and molasses was the additional inductor that presented an increment in cellulases activities: endoglucanase 15%, exoglucanase 81%, and β‐glucosidase 55%.

Maximum Efficiency Point Tracking Algorithm for Resonant Full-Bridge Converter in Charging Applications

In this paper, a novel maximum efficiency point tracking algorithm is proposed for a resonant DC-DC power converter in charging applications. Based on a total harmonic analysis (THA), a method for minimizing the harmonic content of the input AC current is investigated. An online algorithm is proposed for achieving the maximum efficiency at the whole charging spectrum, by controlling the angle under which zero-voltage switching occurs. The suggested control algorithm is simple to implement with very low computational complexity. Additionally, an effective winding method is proposed for increasing the leakage inductance without greatly increasing the air gap, thus eliminating the need for additional resonant inductors. A prototype converter of 2kW|20A is implemented for verifying the proposed method and 98% maximum efficiency is achieved.

An integrated LNA‐phase shifter in 65 nm CMOS for Ka‐band phased‐array receivers

SummaryIn this paper, a vector‐sum phase shifter (VSPS) integrated with a wideband high‐gain low‐noise amplifier (LNA) for Ka‐band phased‐array receivers is presented. The digitally controlled VSPS based on the RF phase shifting architecture consists of a modified I/Q signal generator with additional inductor resonance and a programmable variable gain amplifier (VGA) based on Four 3 × 4 transistor arrays. Besides the reduced parasitic effect of the I/Q signal generator, an Equidistant Contraction Technology (ECT) is used in the VGA, to maintain higher phase shift accuracy of the VSPS. A multistage LNA with series inductor peaking is adopted to fulfill the flat wideband gain, where LC resonance networks are used as interstage matching to compensate for gain roll‐off at a higher frequency. Based on simulations in 65 nm CMOS technology, the presented LNA‐Phase shifter has achieved an average NF of 3.24–3.66 dB, and an average gain of 13.1–23.6 dB. Moreover, an RMS phase error of 1.1–12.6°, an RMS gain error of 4.2–5.6 dB, and an RMS magnitude error of 2.1–2.8 dB are maintained across 27–40 GHz, with a 360° phase shift coverage in steps of approximately 2.8125°. The chip consumes 16.83 mW from a 1.2 V supply voltage, and the occupied area is 0.65 mm2.

A Family of Impedance Source DC-DC Converters With Zero Input Current Ripple

A family of impedance source DC-DC converters with zero input current ripple is proposed in this paper. The proposed converters include one additional input inductor, a capacitor and a winding coupling with the Y-source on the input side of the original impedance source converters. The voltage of the added winding is opposite of that of the input inductor. Accordingly, the input current ripple can be reduced to zero. Moreover, the two input inductors can be coupled, it means only one capacitor and two windings are needed to be added in the proposed converter. Above all, the proposed converters can promote the life of the photovoltaic array due to the reduction of the input current ripple. In addition, the proposed converters inherit all advantages of the original converters, like high voltage gain and low voltage stress. Detailed theoretical analyses and experimental tests verify the validity of the proposed converters.

A Self-Bias-Flip With Charge Recycle Interface Circuit With No External Energy Reservoir for Piezoelectric Energy Harvesting Array

This paper presents a piezoelectric energy harvesting (PEH) interface circuit using a new self-bias-flip with charge recycle (SBFR) technique without employing any additional energy reservoir. Traditional designs, including synchronous-switch harvesting on inductor (SSHI), synchronous-switch harvesting on capacitor (SSHC), synchronous electric charge extraction (SECE), etc., require additional capacitors or inductors to reverse the voltage on the PEH at the zero-crossing point. This design innovatively uses the inherent capacitors of the piezoelectric harvesters as the flipping capacitors. In order to improve the extract efficiency of the interface, the zero-crossing state is split into charge recycle stage and voltage-flip stage. For a piezoelectric array with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$2^{n}$</tex-math></inline-formula> PEHs, a configuration with (n-1) phases in the charge recycle stage is adopted to reduce the loss caused by direct charge neutralization. The charge redistribution loss is reduced by employing (2n+1) phases in the voltage-flip stage. The proposed principle has been implemented with discrete components and is verified by 3 different prototypes. The measurement results show that a flipping efficiency of 67% is achieved by utilizing SBFR with 4 PEHs. And the proposed interface can provide up to 5.2x improvement when compared with the full-bridge rectifier (FBR).

A novel bridgeless flying capacitor multilevel rectifier

SummaryA novel transformerless three‐phase unidirectional bridgeless flying capacitor (UBFC) rectifier for medium‐voltage and high‐voltage applications is presented in this paper. The rectifier consists of three single‐phase rectifiers in wye connection; the DC outputs of the three single‐phase rectifiers are connected in parallel to provide a high common DC‐link bus, which makes it convenient to connect with neutral point clamped (NPC) or flying capacitor (FC) multilevel inverters. To avoid phase‐to‐phase current circulation, an additional inductor and diode are added to each single‐phase rectifier. Compared with conventional bidirectional multilevel converters, only half IGBTs are used, the voltage stress is lower, and the line‐frequency transformers are no longer required, which makes the proposed rectifier has a series of advantages such as reduced cost, simplified control complexity, increased reliability and improved overall efficiency. The basic operating principle of the proposed rectifier in continuous conduction mode is discussed; an improved carrier‐based level‐shifted pulse‐width modulation (PWM) method integrated with voltage balancing and the double closed‐loop control strategy are proposed to achieve more voltage levels and keep the flying capacitors in balance. The feasibility of the proposed rectifier is verified by the simulation and experimental results.

Studying Interoperability of Different Compensation Networks in Inductive Power Transfer Systems

The issue of interoperability between electric vehicles and different wireless chargers, resulting from the diverse compensation networks, is impeding the engineering application of IPT technology. The objective of the paper is to investigate the interoperability of different compensation networks for inductive power transfer systems. The study analyses three potential cases of compensation design, which include LCCS, SLCC, and LCCP compensation networks. To evaluate the performance of these networks, a proposed analytical methodology is utilized to delve into the power factor of the compensation networks. Additionally, in order to assess their sensitivity to parameter changes, the power displacement under mistuned conditions is calculated by adding additional series inductors to the main coil. Finally, the proposed analysis is validated by simulation models, which indicate that the SLCC network has better tolerance to parameter variations under mistuned conditions.

An Active Inductor Based Transimpedance Amplifier with Two Local Feedbacks as a Fiber Optic Application

An important use of active inductor feedback is reported. It was evident that a frequency dependent impedance of an active inductor is similar to that of an ordinary spiral inductor which is a key advantage in integrated circuit design given the fact that Mosfet-based active inductor circuit occupies less volume on board a chip. In this work, a 42 dBΩ transimpedance (TIA) gain at 1 GHz is obtained with 33 𝑝𝐴⁄√𝐻𝑧 of input referred noise with a very low power consumption of 0.605 mW. The Common-Gate Common-Source input stage with an active inductor feedback is reported in this work for the first-time long side a second stage current mirror with additional local active inductor feedback. The extremely low level of power consumption is considered to be another key advantage for that matter despite the moderate levels of TIA gain, bandwidth and input-referred noise current spectral density with 1V DC supply voltage. The LTspice software was used for simulation.

Flexible Passive Sensor Patch with Contactless Readout for Measurement of Human Body Temperature.

A passive flexible patch for human skin temperature measurement based on contact sensing and contactless interrogation is presented. The patch acts as an RLC resonant circuit embedding an inductive copper coil for magnetic coupling, a ceramic capacitor as the temperature-sensing element and an additional series inductor. The temperature affects the capacitance of the sensor and consequently the resonant frequency of the RLC circuit. Thanks to the additional inductor, the dependency of the resonant frequency from the bending of the patch has been reduced. Considering a curvature radius of the patch of up to 73 mm, the maximum relative variation in the resonant frequency has been reduced from 812 ppm to 7.5 ppm. The sensor has been contactlessly interrogated by a time-gated technique through an external readout coil electromagnetically coupled to the patch coil. The proposed system has been experimentally tested within the range of 32-46 °C, giving a sensitivity of -619.8 Hz/°C and a resolution of 0.06 °C.

Control of a Segmented Three-Phase Synchronous Motor With Highly Coupled Subwindings

This article addresses the control issue of a structure enabling the segmentation of three-phase electric drives. The proposed segmentation process offers an additional degree of freedom in terms of voltage rating for power electronics but results in a three-phase system with highly coupled sub-windings. Thus, for such a segmented motor, the true challenge lies in controlling the machine global electromagnetic torque while balancing the power among the different inverters. To tackle this issue, the dq standard synchronous frame is extended to common and differential modes. This approach enables to design a suitable control structure based on an analytical model and physical considerations. The developed model is calibrated with realistic numerical values obtained from a finite element analysis. Finally, an experimental setup allows developing a proof of concept which shows the interest of the proposed control method compared to a standard multiple dq-frame method. The key finding is that the above-mentioned control objective of the segmented synchronous motor can be achieved without additional inductors and despite the severe constraint imposed by such highly coupled segmentation.

Wide zero‐voltage switching range full‐bridge converter based on adjustable parallel current

AbstractAiming at the problems of narrow ZVS range, large duty cycle loss, and severe voltage oscillation of phase‐shift‐controlled full‐bridge converters, this paper proposes a converter that realizes ZVS by adjusting the parallel current. No additional series inductor is required, avoiding large duty cycle loss and weakening voltage oscillations on the secondary side. The converter with small duty cycle loss can use a transformer with a larger turns ratio, which can reduce the voltage stress of the secondary diodes and the filter inductor current ripple. The parallel current required to realize ZVS is analyzed theoretically considering the influence of leakage inductor energy on ZVS. A comparative experiment between the proposed converter and the conventional full‐bridge converter is carried out to verify the performance of the proposed converter.

An Adaptive Estimator Based Sliding Mode Control of Nonisolated Single-Input Double-Output Cuk Converter

This article presents an adaptive estimator based sliding mode control (AESMC) for a single-input dual-output (SIDO) converter used in applications requiring multiple regulated output voltages. The proposed SIDO converter is synthesized from the conventional Cuk converter by inserting an additional switch and inductor. However, the coupled capacitor present in the proposed converter topology leads to cross-coupling (CC) and cross-regulation (CR) issues, resulting in the instability of the converter. Furthermore, these issues increase the parameter design and control complexity of the converter. Therefore, this article proposes AESMC to address the CC and CR issues present in the converter. The adaptive estimator of AESMC facilitates the design of adaptive law for effectively estimating the system disturbances. Then, based on the estimated parameters, the input of the SMC is designed to generate switching pulses. Furthermore, the effectiveness of the AESMC in eliminating CC and CR effects is validated by comparing the results obtained with the decoupler+PI controller. Moreover, the system stability analysis with the proposed control technique is presented by considering the Lyapunov direct method. The effectiveness of the proposed control algorithm is evaluated in MATLAB/Simulink, and the obtained results are validated in a hardware prototype developed in the laboratory.

Control strategy for the magnetic energy storage and transfer system (MEST)

The Magnetic Energy Storage and Transfer system (MEST) aims at improving the power handling in supplying the SuperConducting (SC) coils of fusion experiments. It is based on smart use of Superconducting Magnetic Energy Storage technology and allows the introduction of a certain degree of decoupling between the grid and the load. The MEST operation is based on the storage and transfer of the needed energy between the Load Coil (LC) and an additional storage inductor named Sink Coil (KC); the energy transfer is realized via capacitors switched by fully controllable semiconductors.This paper focuses on the control system of the MEST and proposes a control strategy, based on two decoupled control loops, with the aim both to guarantee the desired current on the load coil and the compensation of the system losses. A model of the MEST with the proposed control system has been developed to analyze the performance through numerical simulations. The control strategy and the simulation results will be presented and discussed in the paper.