Parasitic Parameters Research Articles

Wideband Modeling of Power SiC mosfet Module and Conducted EMI Prediction of MVDC Railway Electrification System

The SiC mosfet in the medium-voltage direct-current (MVdc) transportation electrification system features faster switching performance, while simultaneously binging more significant electromagnetic interference (EMI) issues within the rolling stocks, substations, and radiated disturbance into space along the catenaries and tracks. Due to the necessity to involve both the transient characteristics of power semiconductor devices and the stray parameters of all the equipment in the analysis of EMI, it is considerably challenging to perform wideband device-level simulation on traditional commercial software for such a complex system with numerous trains and stations. A computationally efficient method for wideband modeling and simulation of the MVdc high-speed railway system for the assessment of conducted EMI during the project design stage is proposed in this article. Physical characteristics of the semiconductor devices, parasitic parameters of the mosfet package, and converter topology are all taken into consideration to provide not only accurate system-level performance of the system but also an insight into high-frequency characteristics under different operation conditions. The calculation burden is alleviated by a hierarchical circuit partitioning architecture based on the frequency-dependent time-domain transmission line model and the Norton equivalent parameter extraction of each mosfet module to split the whole system into several smaller subcircuits in terms of matrix size, and a fully parallel implementation of the MVdc system is carried out on the graphics processor. The developed program is used to study the case of Jing–Zhang high-speed railway system topology, which is compatible to be modified to the MVdc project. Simulation results show that it is essential to estimate the EMI level comprehensively considering the alternative of speed and dc voltage.

Study on differential mode conducted interference of trigger circuit of high-power thyristors in pulsed power supply

The trigger circuits of high-power thyristors in pulsed power supply (PPS) contain a large number of pulse transformers, switching MOSFETs (SMFETs) and other passive devices. Fast on-off of SMFETs and pulse transformers often lead to differential mode conducted interference (DMCI) problems in trigger circuits of high-power thyristors. This paper mainly disscusses DMCI problems in trigger circuits of high-power thyristors in the following aspects: initially, circuit models of high-frequency parasitic parameters of pulse transformer and SMFET are established; next, principles of DMCI in trigger circuits of high-power thyristors are investigated; furthermore, DMCI suppression methods are also analyzed; ultimately, experiments have been carried out to verify the theoretical analysis.

Fast Commutation of DC Current Into a Capacitor Using Moving Contacts

This paper describes a method of fast commutation of DC current into a capacitor. Theoretical study is provided, which enables evaluation of commutating DC current for the given contact velocity, capacitance, and dielectric strength. It is concluded that a non-zero contact velocity at separation is required, and a corresponding switch design is proposed. Experimental results on a laboratory setup illustrate successful DC current commutation up to 400 A, with voltages rising to 1.3 kV. Further experiments demonstrate that parasitic parameters reduce the magnitude of the current that can be commutated. A detailed non-linear PSCAD model and a linear model for the parasitic circuit are presented to enable prediction of the success of commutation. The model accuracy is confirmed with experimental tests. The DC current commutation in the proposed method occurs 5–10 μs after the contact separation, which is much faster than with other methods employing moving contacts. A further benefit of the extremely short arcing is the elimination of thermal issues on contacts, and possible simplified design of the mechanical switch.

Schottky Diode Large-Signal Equivalent-Circuit Parameters Extraction for High-Efficiency Microwave Rectifying Circuit Design

A novel parameter extraction method for the Schottky diode’s large-signal equivalent-circuit model is proposed, and used to design high-efficiency microwave rectifying circuits. This method extracts the nonlinear SPICE parameters in the equivalent-circuit from measured I-V and C-V data, and the linear parasitic parameters from the broadband small-signal S-parameters. Moreover, it employs a de-embedding technology that adopts an equivalent circuit to remove the influence of the test fixture in the S-parameters measurement, thereby additional TRL calibration kits are not required. As a sample, large-signal equivalent-circuit parameters of the Schottky diode with model number MA4E1317 are extracted by the proposed method. Then it was used to design two Class-F microwave rectifying circuits working at 2.45 GHz and 5.8 GHz, respectively. Owing to the high accuracy of the extracted parameters by the proposed method, the simulation results such as the large-signal transient voltage waveforms across the diode agree well with the measured ones. Furthermore, two rectifying circuits exhibit very high rectifying efficiencies (e.g., 83.5% at 2.45 GHz and 82.1% at 5.8 GHz with 16.8 dBm input power).

Photocharge-Modulated Passive Intermodulation on Ag₂O/Ag Junction in High-Power Microwave Devices

This letter studies the photocharge-modulated passive intermodulation (PIM) effect on the Ag <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O/Ag contact junction. It is demonstrated that the photocharge with the parasitic parameters on the contact junction can modulate the electron transport process and make the PIM components changed with photoillumination. The linear RC constant can change the nonlinear current strength, under the periodical photostimulation, and PIM components will vary with the photopulses. In the experiment, by using a specially designed coaxial fixture to measure the PIM response with RC components on the contact junction, a semianalytical model for this photoeffect-modulated contact PIM is demonstrated.

Algorithm for Indirect Measurement of the Parameters of the Passive Complex Conductivity of a Two-Terminal Circuit in a Multipole Electrical Circuit

An algorithm is proposed for indirect measurement of the parameters of the passive complex conductivity as a separate two-terminal circuit and also as a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit without needing to separate it into separate two-terminal circuits. A structural diagram is presented for a microprocessor device to measure the parameters of the passive complex conductivity of a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit. The algorithm for the indirect method of measuring the parameters of the passive complex conductivity of the two-terminal circuit is based on the theory of matrices and nondirectional graphs. Equations are obtained for calculating the modulus and components of the passive complex conductivity of a two-terminal circuit located in a multipole triangle-type electrical circuit. The proposed algorithm avoids the methodological error owing to the influence of parasitic parameters. Results are presented from an experimental test of the algorithm for indirect measurement of the conductivity of a two-terminal circuit.

Design of Single-Turn Air-Core Integrated Planar Inductor for Improved Thermal Performance of GaN HEMT-Based Synchronous Buck Converter

Gallium nitride (GaN) high electron mobility transistor (HEMT) has a lateral device structure with wafer-level packaging, which is advantageous in minimizing parasitic parameters and overall device size. This type of packaging also has better thermal performance than conventional packaging due to low junction-to-bottom thermal resistances. It indicates copper layers in printed circuit boards can effectively serve as heat dissipation channels for the switching devices. When these copper traces and pours in the vicinity of the switching devices are carefully designed and shaped, they can also be utilized as an integrated output filter. In this article, a synchronous buck converter with a single-turn air-core integrated planar inductor is proposed to achieve both zero-voltage switching and high thermal performance of the GaN HEMTs. A new planar inductor design flowchart is introduced, and analytically estimated inductance and resistance are verified with simulation and experiment. Three different inductors are designed and fabricated to prove the improved thermal performance of the proposed converters.

Impact of Threshold Voltage roll off in Ultra Thin Fully Depleted Silicon on Insulator MOSFET

This article is discussing about threshold voltage roll off effect in Ultra Thin Fully Depleted Silicon on Insulator MOSFET. The device performance is improved due to the reduction in threshold voltage roll off. The thickness of oxide layer is optimized to 2nm which also have a vital role in improvement of device’s throughput. The effect of oxide thickness on parasitic parameter also discussed. Device conductance and transconductance also take in account on simulating the ultra thin fully depleted SOIMOSFET.

Monitoring Bond Wire Defects of IGBT Module Using Module Transconductance

Monitoring the defective insulated gate bipolar transistor (IGBT) module is a cost-effective approach to improve the quality of customer service. In general, the parasitic parameters of bond wires inside the IGBT module are affected by aging. Module transconductance reflects the characteristics of the IGBT module and contains information about bond wire health status. It is investigated as a precursor parameter to monitor the bond wire defects in this article. The mathematical model of module transconductance is deduced to establish the relationship between module transconductance and the parameter of bond wires, which indicates that the module transconductance decreases with the increase of bond wire defects. For accurate and safe measurement, the influence of temperature difference caused by bond wire defects during measurement and safety measurement area where the module operates in the active region are discussed. Based on the safety measurement area and the method to eliminate the difference in temperature, a pulse ramp drive circuit is proposed to extract module transconductance. The simulation and experiments are carried out to validate the feasibility of the measurement method and correctness of the theoretical analysis.

Impact of Intercalation Doping on the Conductivity of Multi-Layer Graphene Nanoribbon (MLGNR) in On-Chip Interconnects

Graphene nanoribbons are considered potentially suitable and have exhibited excellent results in on-chip interconnects. In order to evaluate the different circuit impedance parameters of multi-layer graphene nanoribbons (MLGNRs), an electrical equivalent single conductor (ESC) along with an analytical model is proposed. On the basis of an electrical model, the impact of intercalation doping on the performance of MLGNRs at 32, 22, and 16[Formula: see text]nm technology nodes is discussed in this paper. Moreover, it is also discussed that the increase in intercalation doping increases the Fermi energy of the layers of the MLGNR, which increases its overall conductivity. The fact that the variation in the Fermi energy will have a considerable impact on the parasitic parameters of the MLGNR interconnect at three different technology nodes (32, 22, and 16[Formula: see text]nm) for variable global lengths (500–2000[Formula: see text][Formula: see text]m) is also analyzed. To estimate and compare the performance in terms of delay and power delay product (PDP) of MLGNRs, the simulation program with integrated circuit emphasis (SPICE) simulation tool is used. The results also show that the increase in the Fermi energy improves the performance of MLGNRs in terms of delay and PDP at three different technology nodes. Furthermore, a comparative analysis of all three technology nodes is performed with the copper interconnect, and it is revealed that the MLGNR interconnect is considered to be a prominent material for the next-generation on-chip very-large-scale integration interconnects.

Investigation of Various Transformer Topologies for HF Isolation Applications

High-frequency (HF) transformers are an essential part of many power electronic devices. The performance and behavior of HF transformers can greatly affect the efficiency and performance of all systems, particularly, from a parasitic parameter point of view. In this article, HF transformers’ parasitic parameters, such as leakage inductances and parasitic capacitances, are analyzed using a novel analytical method, finite element method (FEM), and experimental measurements of different structures and winding arrangements. Also, the magnetic field, electric field, electric displacement field, and electric potential distribution within the transformers are simulated and analyzed. Four different HF transformers with E and U cores with different windings are designed and analyzed. Investigation outcomes help to classify structures according to the trade-off between leakage inductances and series parasitic capacitances. This information can later be used for the optimal selection and design of transformers as a function of their operating frequency for any power rating and voltage level. Moreover, 3-D FEM and experimental results validate the proposed methodology to be used for designing HF transformers in high-voltage/power applications.

A new analytical conducted EMI prediction method for SiC motor drive systems

Abstract Although silicon carbide (SiC) devices can greatly improve the energy efficiency of electric motor drive systems and increase the power density of inverters as well in electric vehicle applications, fast switching and high-frequency operations of the devices bring more serious electromagnetic compatibility (EMC) problems. It is very important to predict the electromagnetic interference (EMI) level of SiC motor drive systems at design phase. However, since the megahertz resonances caused by the system parasitic parameters can’t be ignored, conventional EMI prediction methods need to be improved. In this paper, the fast switching transient of SiC devices, the power module parasitic parameters, and other detailed circuit parameters are modeled into the EMI sources and propagation paths. In the differential mode (DM) and common mode (CM) EMI sources modeling, both the equivalent switching current sources and the equivalent switching voltage sources of SiC devices are simultaneously taken into account. The proposed analytical method can accurately predict conducted EMI in the SiC motor drive system in frequency range from 150 kHz to 30 MHz. Compared with the previous conventional methods, the proposed method improves DM EMI prediction accuracy of the SiC motor drive system in high frequency range.

LLC Resonant Converter With Damping Split Inductor Improving Light-Load Regulation Ability

LLC resonant converters are widely used in On-board Power Converter but the pumping voltage of traditional LLC converter is unavoidable under light-load conditions due to the existence of parasitic parameter. In this paper, an LLC resonant converter with damping split inductor is proposed to improve the light-load regulation capability. The original resonant inductor is divided into two parts in series. Then, a simple damping resistor connected on one part in parallel and the other part can be integrated into the transformer. Using damping split inductor, significant regulation improvements could be achieved under light-load conditions with not any change in control strategy and almost zero hardware cost. In addition, based on impedance analysis of the resonant tank, the effects of the proposed method are analyzed including voltage gain, soft switching characteristics, suppression of high frequency interference components, and system power loss. Moreover, the detailed design process and optimization conditions of the damping split inductor parameters are carefully illustrated. Eventually, the experimental results demonstrate the characteristics mentioned above for the 96 W prototype at the expense of a maximum increase in device loss of 0.85 W.

Driver circuit to eliminate bridge leg crosstalk in SiC MOSFETs

This study involves the crosstalk caused by the high-frequency parasitic parameters in the driver circuits of SiC MOSFETs, which are high-speed switching devices. A lumped parameter model for the high-frequency crosstalk of a driver circuit was established. Then, the relationships between the parameters and crosstalk of the driver circuit were analyzed. Finally, an improved SiC MOSFET driver circuit was proposed. The optimized driver circuit parameters can reduce the driver signal oscillation and minimize the crosstalk of the driver circuit. Verification was performed on a test platform of a full-bridge LLC converter. Test results show that the improved driver circuit can remarkably suppress crosstalk, increase the turn-off speed of SiC MOSFETs and reduce the switching loss. This demonstrates the effectiveness of the driver circuit.

Prevalence, intensity and pathology of the nasal parasite Nasicola hogansi in Atlantic bluefin tuna (Thunnus thynnus).

Ectoparasitic flatworms of Nasicola (Monogenoidea: Capsalidae), which infect nasal epithelium of true tunas (Thunnus spp.), are not well studied, nor have their impacts on the host's olfactory organ been evaluated. Infections of Nasicola hogansi on Atlantic bluefin tuna, Thunnus thynnus, were investigated with emphasis on the relationship between infection prevalence, abundance and mean intensity with bluefin tuna size, sex, body condition and capture month, as well as histopathological effects. Commercially caught Atlantic bluefin tuna (n=161, 185-305cm curved fork length) from the Gulf of Maine were sampled during June through August 2009 for infections by N.hogansi. A total of 247 specimens of N.hogansi were collected, with a prevalence of 45.3%, mean abundance of 1.57 (CI: 1.21-2.03) and mean intensity of 3.45 (CI: 2.91-4.22). Neither fish sex nor landing month had a significant effect on parasite parameters. Larger and better-conditioned Atlantic bluefin tuna had a higher mean intensity of infection. Pathology associated with infection by N.hogansi included extensive necrosis, sloughing of the nasal epithelium and associated inflammation of underlying connective tissues. Further epidemiological and pathological study of this host-parasite system is warranted since impaired olfaction, if present, could adversely affect spawning and migration of this top ocean predator.

Matrix Extraction of Parasitic Parameters and Suppression of Common-Mode Conducted Interference in a PMSG-IDOS Rectifier Module

The rectifier module is the key part of a permanent magnet synchronous generator integrated DC output system (PMSG-IDOS) with low-voltage and high-current. The high-speed switching device of the rectifier module is the main source of electromagnetic interference (EMI). In this paper, the matrix extraction method is proposed to establish an accurate conducted interference model, and a 3D crimped SiC MOSFET model is established via Ansoft Q3D simulation software. The matrix of the parasitic parameters between poles of the MOSFET is simulated to extract the accurate parasitic parameters. Furthermore, a high-precision conducted interference simulation model of the pulse width modulation (PWM) rectifier system is established. Then, the space vector pulse width modulation (SVPWM) jump-backward control strategy based on the three-phase four-leg structure is proposed to suppress the common-mode interference, and the comparison with other two methods is carried out based on this model. Finally, the experimental platform of a 5 V/1000 A synchronous generator with rectifier is constructed, and conducted interference is tested in accordance with the simulated results. It demonstrates the accuracy of the model with parasitic parameters based on the matrix extraction method. This paper provides a more simple and effective reference method for the prediction study of conducted interference in power converter systems. After comparing the simulation results with the experimental results, it is proven that the SVPWM jump-backward control strategy based on the three-phase four-leg structure can ensure the output balance of the bridge leg and allow the common-mode (CM) interference to reach the ideal state.

RF modeling and parameter extraction for GaAs‐based on‐chip inductors

AbstractRF modeling and equivalent circuit model parameter extraction for GaAs‐based on‐chip inductors are presented in this article. An improved model that takes into account of the substrate loss effects based on the S parameters on wafer measurement is proposed. The parameter extraction method combines the analytical expressions and the empirical optimization procedure, which does not require any additional test structures. The intrinsic elements determined by utilizing the analytical method are described as functions of the parasitic elements. After that, an advanced design system is used to optimize the parasitic parameters with very small dispersion of initial values. Good agreement is obtained between the simulated and measured data up to 50 GHz.

Modeling and Validation of Common-Mode Emissions in Wide Bandgap-Based Converter Structures

Modern power converters designed with wide band-gap (WBG) semiconductors are known to generate substantial conducted electromagnetic interference (EMI) as a side effect of high-edge-rate and high-frequency switching. This article provides a consolidated treatment of an approach to the derivation of common-mode equivalent models that are useful for analyzing this increased EMI signature. Also included is a step-by-step demonstration of this approach applied to a prototype converter that exemplifies many practical power electronic applications. For empirical validation of the developed model, this converter is operated within a custom-designed EMI characterization testbed that is similar to the setup specified by MIL-STD-461 CE-102. Good agreement is achieved between analytical predictions and empirical results in both the time domain and the frequency domain. Spectral comparisons are shown to be especially accurate in the frequency range between 10 kHz and 30 MHz, which is the principal range of interest for controlling conducted emissions in WBG-based systems. In order to achieve the demonstrated model agreement, a set of parasitic parameter values were obtained through impedance characterization of the system under study. Identification of the critical parasitic elements that must be quantified to achieve good predictive capability for the presented model represents one of the specific contributions of this article.

Fuzzy-Modeled Prescribed Performance Integral Controller Design for Nonlinear Descriptor System With Uncertainties

A suitable solution for a nonlinear descriptor system with uncertainties is considered in this paper by designing a fuzzy-modeled prescribed performance integral controller. The system with a parasitic parameter $\varepsilon $ is known as the descriptor system, and this parasitic parameter is used for specifying a fast mode of such a system. Based on a linear matrix inequality (LMI) approach, the interaction of fast and slow dynamic modes which causes ill-conditioned LMI result has normally occurred in the nonlinear descriptor system with uncertainties. Therefore, with the design of the fuzzy-modeled prescribed performance integral controller, such a system with parametric uncertainties is represented by a Takagi-Sugeno fuzzy model, and the $H_{\infty } $ fuzzy state-feedback controller is designed to achieve an adequate condition for overcoming the effects of the parasitic parameter, the uncertainties, and the exogenous input disturbance. Moreover, the integral controller is added to increase the performances of stability. In summary, the design process of the proposed controller and the numerical example serve to illustrate various performance results of the proposed controller.

Improved Phase Shift Control for SiC-MOSFET Based Resonant Switched-Capacitor Converter with Parasitics Consideration

In this article, the resonant switched-capacitor converter (RSCC) is applied to the auxiliary power system of electric locomotive to improve its efficiency and power density. Phase shift control is generally applied to the RSCC for voltage regulation. But the dead time and parasitic parameters impose the negative effects on the switching transit, the resulted hard-switching process may cause extra switching loss. An optimized soft- switching realized method is proposed under phase shift control. First, transient analysis of resonance is carried out by state trajectory, and steady-state characteristics are discussed. Then, the influence of parasitic parameters on resonant current and output power is discussed. Moreover, the dead-time effect and soft-switching condition are analyzed; therefore, a high-efficiency control strategy with zero-voltage switching is proposed. Experimental results show that the proposed optimization control strategy can improve the efficiency up to 99.4%.