High Voltage Transients Research Articles

A Self-Biased Triggered Dual-Direction Silicon-Controlled Rectifier Device for Low Supply Voltage Application-Specific Integrated Circuit Electrostatic Discharge Protection

A direct bidirectional current discharge path between the input/output (I/O) and ground (GND) is essential for the robust protection of charging device models (CDM) in the tightly constrained design parameters of advanced low-voltage (LV) processes. Dual-direction silicon controlled rectifiers (DDSCRs) serve as ESD protection devices with high efficiency unit area discharge, enabling bidirectional electrostatic protection. However, the high trigger voltage of conventional DDSCR makes it unsuitable for ASICs used for the preamplification of biomedical signals, which only operate at low supply voltage. To address this issue, a self-biased triggered DDSCR (STDDSCR) structure is proposed to further reduce the trigger voltage. When the ESD pulse comes, the external RC trigger circuit controls the PMOS turn-on by self-bias, and the current release path is opened in advance to reduce the trigger voltage. As the ESD pulse voltage increases, the SCR loop opens to establish positive feedback and drain the amplified current. Additionally, the junction capacitance is decreased through high-resistance epitaxy and low-concentration P-well injection to further lower the trigger voltage. The simulation results of LTspice and TCAD respectively demonstrate that ESD devices can clamp transient high voltages earlier, with low parasitic capacitance and leakage current suitable for ESD protection of high-speed ports up to 1.5 V under normal operating conditions.

Controllable Double‐Emulsion Droplet Manipulation Actuated by a Triboelectric Nanogenerator

AbstractElectrically controlled droplet manipulation is attractive for lots of applications ranging from material synthesis and drug delivery. However, the present techniques using bulky and expensive power supplies to generate high‐voltage electrical signals are easy to cause electrode electrolysis, bubble formation in buffer solution, and are incapable for point‐of‐care testing. Herein, a novel and portable electrical method for self‐powered emulsion droplet core coalescence and release based on triboelectric nanogenerator (TENG) is presented. The electrical signal with a 2.25 kV open‐voltage and a 35 µA short‐circuit current can be conveniently generated via frictional electrification effect, and the harmful electrochemical reaction in solutions can be avoided. The high transient pulse voltage and stable sinusoidal signal between two electrodes in microfluidic device can generate a strong electric field, which causes apparent Maxwell electrical stresses at droplet interfaces and subsequently promotes the core coalescence and release of double‐emulsions. By adjusting the voltage magnitude, the core coalescence and release behaviors of double‐emulsion droplets can be controllably achieved, followed by the synthesis copper‐based metal–organic framework (Cu‐MOF) nanoparticles. Thus, this portable, effective and self‐powered droplet manipulation technique can be attractive for those droplet‐based applications.

An Output-Capacitorless LDO regulator with fast transient response and high PSRR

Abstract A fast transient response and high supply voltage rejection ratio (PSRR) output-capacitor-less low-dropout (OCL-LDO) regulator with a dual power transistor structure is proposed in this paper. The designed flip voltage follower (FVF) structure and the proposed back-gate control loop improve the transient performance of the system. The proposed PSRR enhancement circuit transmits the power supply voltage fluctuation 1:1 to the gate of the power transistor so that the influence of the power supply voltage fluctuation on the output voltage of the LDO is offset by the difference between the gate and source voltages of the power transistor. The simulated results have shown that the proposed OCL-LDO regulator achieves full range stability from 100 μA to 50 mA. The output voltage undershoot is reduced by more than 100 mV when the load current is stepped from 1 to 50 mA in 500 ns without the load capacitor. The PSRR enhancement circuit increases the PSRR of the LDO from 1 KHz to 10 MHz by more than 20 dB.

A review of silicon carbide MOSFETs in electrified vehicles: Application, challenges, and future development

AbstractCompared with silicon‐based Insulated Gate Bipolar Transistors (IGBTs), silicon carbide (SiC) Metal‐Oxide‐Semiconductor Field‐Effect Transistors (MOSFETs) are characterized by higher operating temperatures, switching speeds and switching frequencies, and are considered the next evolutionary step for future electric drives. The application of SiC MOSFETs in the field of electrified vehicles has brought many benefits, such as higher efficiency, higher power density, and simplified cooling system, and can be seen as an enabler for high‐power fast battery charging. This article reviews the benefits of SiC MOSFETs in different electrified vehicle (EV) application scenarios, including traction inverters, on‐board converters, and off‐board charging applications. However, replacing Si‐IGBTs with SiC MOSFETs introduces several new technical challenges, such as stronger electromagnetic interference (EMI), reliability issues, potential electric machine insulation failure due to high transient voltages, and cooling difficulties. Compared to mature silicon‐based semiconductor technologies, these challenges have so far hindered the widespread adoption of SiC MOSFETs in automotive applications. To fully exploit the advantages of SiC MOSFETs in automotive applications and enhance their reliability, this paper explores future technology developments in SiC MOSFET module packaging and driver design, as well as novel electric machine drive strategies with higher switching frequencies, and optimized high‐frequency machine design.

Studying Dielectric Losses of Serially Combined Silicone Rubber and Epoxy Resin

High voltage outdoor insulation systems are conventionally ceramics and glass with several advantages, such as proven in the field, excellent dielectric properties, durability, and long life. However, they are heavy, attract vandals and break easily, and they can lose their dielectric properties easily when subjected to high voltage transients, arcing, and surges. To curb this, polymer insulators are used because they have excellent dielectric properties, such as those of ceramics and glass, with the added advantages that they do not break easily and recover their lost dielectric properties after any electrical transients. Therefore, this paper investigates the dielectric properties of polymeric materials – silicone rubber (SR) and epoxy resin (ER). Some SR samples were manufactured in the laboratory, and others were obtained from the industrial manufacturer. All the ER samples were manufactured in the laboratory. The dielectric measurements were performed with the Insulation Diagnostics System. Within the measured frequency ranges, the dielectric losses of SR manufactured industrially differ from the laboratory-manufactured specimens. This is due to filler materials in the industrially manufactured samples. For the case of serially connecting the SR and ER, there was a higher influence of dielectric loss of SR than the ER, with some remarkable dielectric losses at some frequencies.

단일동조 저차 고조파 필터뱅크 과도회복전압

Industrial power systems include lots of non-linear loads which draw in non-sinusoidal currents. These non-sinusoidal currents are harmonic sources in the power systems, leading to power quality issues. A typical way to solve the power quality issues is to install single-tuned harmonic filter banks in parallel that provide low impedance paths for harmonic currents at their tuning orders, allowing for harmonic mitigation. Depending on harmonic orders, single-tuned harmonic filter banks have different switching characteristics: high amplitude and frequency back-to-back inrush currents of high-order harmonic filter banks; and high transient recovery voltage of low-order harmonic filter banks. This paper focuses on the latter to offer beneficial insights on power system design for safe and reliable harmonic filter bank switching. Theoretical analysis with electromagnetic transient studies describes how the high transient recovery voltage occurs in the low-order harmonic filter banks during the open operation of a circuit breaker. A field measurement on a second-order harmonic filter bank with 30 MVar and 33 kV proves that an excessive transient recovery voltage of approximately 92 kV can appear across the circuit breaker terminals. Lastly, this paper discusses the gap between this excessive voltage generated in a field and the test voltage specified in the IEC standard.

A 121.4-dB DR Capacitively Coupled Chopper Class-D Audio Amplifier

This article presents a class-D amplifier (CDA) with high dynamic range (DR). To eliminate the typically dominant noise contribution of a resistive feedback network, the input and feedback signals are chopped and applied to a capacitive feedback network. However, this leads to high-voltage (HV) transients at the input of the loop filter, which, due to timing and impedance mismatch in the chopped feedback network, could degrade linearity and even overstress low-voltage (LV) core devices. Robust processing of the HV chopped feedback signal is guaranteed with chopper timing skew correction, chopper impedance matching, and deadbanding. The prototype, implemented in a 180-nm bipolar-CMOS-DMOS (BCD) process, achieves 121.4 dB of DR, 5.9 dB higher than state-of-the-art closed-loop CDAs, and 8- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{V}_{\mathrm {RMS}}$ </tex-math></inline-formula> output-referred noise (A-weighted). It also achieves a peak total harmonic distortion (THD) + N of −109.8 dB and a peak efficiency of 93%/88% while driving 15 W/26 W into an 8-/4- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> load.

Resistive High-Voltage Probe with Frequency Compensation by Planar Compensation Electrode Integrated in Printed Circuit Board Design

Resistive voltage dividers tend to have a highly non-linear transfer function as parasitic and stray capacitances exert an increasing influence with increasing frequency. The non-linear transfer function depends on the topology and resistors used and consists of a low-pass filter with an additional high-pass component in the GHz range. Due to the non-linear transfer function the measured signal differs from the original input signal. Here, we present an improved resistive voltage divider with additional compensation capacities to extend the linear bandwidth. With this new concept, the linear bandwidth is improved from 115 kHz to 88 MHz, while maintaining a DC input impedance of 10 MΩ. For high-voltage insulation and easy manufacturing, surface mounted resistors on a printed circuit board with a compensation electrode on the adjacent side are used. The performance of this resistive voltage divider is demonstrated by measuring a series of high-voltage pulses with an amplitude of 2.5 kVpeak-peak. The measured pulse rise time is about 16 ns, corresponding to an average slew-rate of 150 V/ns. Finally, the developed resistive voltage divider is successfully used to measure fast high-voltage transients required for advanced ion mobility spectrometers with integrated collision induced fragmentation.

Scaling of Time-Dependent Tunneling Current in Terahertz Scanning Tunneling Microscopes

Terahertz scanning tunneling microscopy (THz-STM) has enabled spatiotemporal imaging with femtosecond temporal resolution and angstrom spatial resolution. In THz-STMs, the junction bias is modulated by coupling THz pulses, which results in transient voltage bias and extremely high transient tunneling currents. In order to have efficient imaging of the sample surface, it is important to understand the nonlinear tunneling current response and its parametric dependence. In this work, we theoretically investigate the basic scaling of rectified electrons in a THz-STM junction. We use a self-consistent quantum model that includes both space-charge potential and exchange-correlation potential, which were ignored in previous studies. Since THz-STMs are operated at high transient voltage in field emission regime, the effects of exchange-correlation potential become crucial. We validate our calculation with recently reported experimental data and investigate the rectification property of the tip-sample junction for different parameters. We find that the time-dependent tunneling current and the electron transport can be manipulated by varying the dc bias voltage (polarity, amplitude), incident THz field (polarity, shape, peak amplitude), work functions of STM tip and sample---especially their difference $\mathrm{\ensuremath{\Delta}}W$, and the tip-sample separation. Our study provides an important framework that can be used in the future to characterize, control, and improve THz-induced currents and probing techniques at the nanometer scale over subpicosecond time periods.

High-Attenuation Wideband Active Common-Mode EMI Filter Section

A high-attenuation wideband active common-mode filter (ACF) section is presented. Each section is composed of an active capacitor and a small common-mode (CM) inductor. The active capacitor is realized by using several coupling capacitors and a class-A bipolar-junction-transistor based amplifier for its low-cost, fast response, and good immunity to high voltage transients. The structure of the amplifier consists of a common-collector amplifier and a high-gain common-emitter amplifier with an active load. The working bandwidth of the ACF ranges from 150 kHz to 30 MHz. By cascading several ACF sections, a multistage structure that exhibits high filtering attenuation can be designed. The number of cascaded sections is optimized by considering the required filtering attenuation. The performance of single-stage and multistage ACFs is evaluated on two commercial power supplies with rated power of 90 and 1000 W, respectively. The CM noise of the power supplies with the proposed ACF and with the original passive filters is compared. The results show that the physical volume of the ACF is significantly smaller than that of the passive filter, and the power dissipation of the ACF is similar to that of the passive filter.

Simulation Study of a High Gate-to-Source ESD Robustness Power p-GaN HEMT With Self-Triggered Discharging Channel

This article proposes a novel power p-GaN high-electron-mobility transistor (HEMT) with self-triggered discharging channel to improve gate-to-source electrostatic discharge (ESD) robustness. The self-triggered discharging channel consists of a small-size self-triggered p-GaN HEMT, a current-limiting resistor R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> , and a proportional amplification resistor R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . At ESD events, the proposed power p-GaN HEMT will be self-triggered by the high transient ESD voltage, and hence the accumulated electrostatic charges at its gate will be released through the self-triggered discharging channel. This avoids the gate-to-source damage of the proposed device, thereby enhancing the gate-to-source ESD robustness. Compared with the conventional power p-GaN HEMT, simulation results show that the transmission line pulsing (TLP) current handling capability (over 6.5 kV human body model failure voltage) of the proposed device is improved by 1900% without compromising other device characteristics. In addition, the fabrication process of the proposed device is fully compatible with the traditional power p-GaN HEMT platform, and the increase of total active area is less than 0.5%. The proposed device with self-triggered discharging channel can be a good reference for the design of power p-GaN HEMT with high ESD robustness.

Perancangan Simulasi Hardware-in-The-Loop Untuk Sistem Manajemen Baterai

In a Microgrid system that relies on renewable energy generation, one of the most important constituent systems is the Battery Energy Storage System because of its vital role in maintaining the stability of the Microgrid in providing power to the load. However, to operate the battery, a Battery Management System is needed to ensure the battery operates at the desired working range, so that battery reliability can be maintained. To determine the behavior of the Microgrid and the designed BMS in accordance with the desired specifications, a Hardware-inthe-Loop (HIL) Simulation has been designed using Simulink to model a DC Microgrid which consists of several sub-systems such as: An ideally designed generator and load as a tester, a bidirectional buck and boost converter with a PI controller, and a battery system equipped with a Switched Shunt Resistor Cell Balancing type, all controlled using the BMS algorithm implemented on Arduino. From the test results, it is found that HIL can communicate with good QoS on various inputs as long as the Arduino sample time meets. Then the PI controller with HIL was able to improve converter performance and also succeeded in controlling cell balancing with the efficiency of charging and idle modes of 99% and 99.4% respectively. Finally, in testing the integrated system, the BMS can maintain the performance of the Microgrid with bus voltage and battery current parameters in various SoC conditions and generator voltage fluctuations, even though there are high voltage transients.

Intelliquench: An Adaptive Machine Learning System for Detection of Superconducting Magnet Quenches

In superconducting magnets, the irreversible transition of a portion of the conductor to resistive state is called a “quench.” Having large stored energy, magnets can be damaged by quenches due to localized heating, high voltage, or large force transients. Unfortunately, current quench protection systems can only detect a quench after it happens, and mitigating risks in Low Temperature Superconducting (LTS) accelerator magnets often requires fast response (down to ms). Additionally, protection of High Temperature Superconducting (HTS) magnets is still suffering from prohibitively slow quench detection. In this study, we lay the groundwork for a quench prediction system using an auto-encoder fully-connected deep neural network. After dynamically trained with data features extracted from acoustic sensors around the magnet, the system detects anomalous events seconds before the quench in most of our data. While the exact nature of the events is under investigation, we show that the system can “forecast” a quench before it happens under magnet training conditions through a randomized experiment. This opens up the way of integrated data processing, potentially leading to faster and better diagnostics and detection of magnet quenches.

Capacitive Power Transfer System with Double T-type Resonant Network for Mobile Devices Charging/Supply

In the applications of wireless power transfer for mobile devices, the pick-up of the wireless power transfer system often needs to be moved in and moved out. A sudden change in the system structure will cause high transient voltages or currents, which could damage the power electronic device of the capacitive power transfer (CPT). In addition, the standby power of the system will be too high to work after removing the pick-up. A CPT system with double T-type resonant networks has been proposed to address these problems. The steady-state models of the system without the pick-up and normal state conditions of it are established. The relationships between the resonant network parameters are analyzed, and a systematic circuit parameter design method is provided. The proposed CPT topology and the parameter design method have been verified by simulation and experiment. The system not only achieved self-protection under severe load change but also entered standby mode automatically after the pick-up was moved out. Besides, the system is restored to the normal state condition when the pick-up is moved in without additional detection and control circuitry.

Deployment of a Resistive Superconducting Fault Current Limiter for Improvement of Voltage Quality and Transient Recovery Voltage

This article presents a theoretical investigation of a resistive superconducting fault current limiter (R-SFCL) operating in a medium-voltage network. The considered power system presents a high level of fault current as well as a high transient recovery voltage. The simulation result shows that the R-SFCL not only limits the fault current to a desirable value, but also improves transient recovery voltage of circuit breakers by eliminating high-order harmonics generated by the opening of the circuit breaker.

Electromagnetic Acoustic Detection of Steel Plate Defects Based on High-Energy Pulse Excitation

The conventional electromagnetic ultrasonic transducers (EMATs) rely on the static magnetic field created by magnets. The magnet increases the size of the EMATs, and the strong magnetic force of the magnet attracts the detected steel and even ferromagnetic particles. It can cause mechanical damage to the transducer and the detected objects. A new high-energy acoustic excitation system, without a static bias magnetic is designed, which does not include any magnets. As the core of the system, the high-energy pulse excitation power supplies a transient high voltage to the excitation coil by the LC oscillation circuit. The maximum amplitude of current can reach 1700 A, which is much larger than the current in the conventional EMATs. Compared with the conventional EMATs, the intensity of the ultrasonic signal is greatly strengthened and the size of the EMAT is effectively reduced. Therefore, it can detect high-temperature steel plates at a higher lift-off distance. In this paper, the transduction mechanism of high-energy pulse electromagnetic acoustic on ferromagnetic materials was studied, and the high-energy pulse excitation coil used for the A0 mode Lamb wave was designed. The interaction rule of the magnetic field, the force field, and the acoustic field, was obtained. Then, the EMAT lift-off characteristic experiment of the high-energy pulse excitation was carried out, and the defect detection experiment was conducted on a cracked steel plate. The results show that the A0 mode Lamb waves have caused a high signal-to-noise ratio and can accurately locate the crack, which has a great advantage in detecting the microcrack defects of ferromagnetic materials.

Analysis and Mitigation on Switching Transients of Medium-Voltage Low-Harmonic Filter Banks

This paper presents the switching transients of medium-voltage low-harmonic filter banks, which have alower back-to-back inrush current and higher transient recovery voltage (TRV) compared with capacitor banks. The switching transients of the filter banks are described by the analytical approach and field measurements for 150 MVA back-to-back filter banks are provided to support the switching phenomena described in this paper. As a mitigation measure of the high transient recovery voltage, a double-breaker type switchgear is analyzed in terms of the operating sequence and the time of the upper and lower breakers. From the analyses, an operation scheme for the double-breaker switchgear is proposed to avoid insulation failure of the breaker during the interruption by mitigating the transient recovery voltage across each breaker.

Diode-Bridge Multiport Hybrid DC Circuit Breaker for Multiterminal DC Grids

Hybrid dc circuit breaker (HCB) is currently the most promising dc circuit breaker. However, since it requires hundreds of semiconductor switches to withstand high transient interruption voltage, the implementation cost is high. Besides, in the multiterminal dc grid, three or more HCBs may be required at a dc bus, which worsens the disadvantages of HCBs in economy and volume. In order to solve this problem, this article designs a diode-bridge multiport HCB (DB-MPB) with its control procedures. By integrating the n HCBs at the dc bus to a single n-port HCB, the number of semiconductor switches and the footprint can be reduced, while the good current interruption performance can be still maintained. Besides, for the possibility of ultrafast disconnector (UFD) failure, the proposed DB-MPB has the function of UFD failure protection. The effectiveness of the designed DB-MPB under different scenarios is verified by simulations and experimental tests. In addition, the performance comparisons in economy and functionality of the proposed DB-MPB with existed solutions are presented to highlight the advantages of the proposed solution.

A study of high transient voltage unit realization uncertainty

The problem of metrological support of high-voltage pulse generators with subnanosecond rise time, as well as pulse voltage dividers used in power engineering, aviation and rocket-space industries, has been solved. As a result of the modernization of the State primary special standard of transient electric and magnetic field strengths units with a pulse rise time in the range of 0.1–10.0 ns GET 148-2013, a mode of realization a unit of high transient electric voltage with a minimum pulse rise time of 100 ps was implemented. Uncertainties of high transient electric voltage unit realization obtained by numerical simulations using the Monte Carlo method, as well as in accordance with the Guide to the Expression of Uncertainty of Measurement (GUM), are estimated. Also, the error of a unit realization was estimated in accordance with GOST 8.381-2009 “GSI. Standards. Methods to Express Accuracy”.

A Three-Phase Adaptive Reclosure Technology for Distribution Feeders Based on Parameter Identification

A scheme is proposed to improve the decreasing success rate of reclosing in a non-effectively grounded system with a wide application of cables. An inverter source is momentarily connected to the low-voltage side of a service transformer by controlled thyristors to apply a transient high voltage to the de-energized feeder before reclosing. Based on the idea of parameter identification, the internal structure of the de-energized feeder is investigated according to the frequency characteristics of the reference parameters to determine whether the feeder still experiences the fault. The influence of the firing angle on the strength of the frequency components in the transient waveforms is analyzed to determine its range for accurate measurement of feeder harmonic impedance. A sensitivity analysis on the fault property detection criterion is conducted, and the selection of the inverter source power impacted by the firing angle is provided. The results of the theoretical analysis, computer simulation, and lab experiments confirmed the effectiveness of the proposed scheme.