Chenguo Yao

• PhD
• Chongqing University

Two major reasons why chemotherapy and immunotherapy have limited efficacy in treating gliomas are the blood-brain barrier and the dense, solid structure of the glioma. Pulsed electric fields have been a powerful tool for ablating solid tumors, and narrowing pulse duration can improve the field homogeneity penetrating into the tumor. In this study,...

传统封装的高寄生电感限制了SiC MOSFET串联开关的开启速度。本文设计了一种面向芯片级高压串联SiC MOSFET模块的Π形超紧凑封装，可将16级/20 kV的串联开关寄生电感削减至55.8 nH。首先，研究了超紧凑封装结构参数对回路寄生电感和电场分布的影响。结果表明，板间距的减少能够显著降低寄生电感，然而其缩小受到绝缘可靠性的阻碍。为解决超紧凑封装绝缘问题以实现寄生电感极限削减，分别提出了相应的局放探测和绝缘增强方法。首先，提出了一种基于共模电荷测量的局放监测方法，用于脉冲电应力下局部放电起始电压（PDIV）的准确测量。随后，通过六方氮化硼（hBN）填料改性与复合提高了硅胶灌封料的绝缘，PDIV测量结果显示其满足了较小板间距封装的绝缘需求，从而实现了寄生电感的极限削减。此外，为了将超紧...

Objective: Glioblastoma (GBM) is the deadliest type of cancer and current clinical treatments for malignant gliomas have many side effects. The article discusses the possibility that nanosecond pulsed electric fields (nsPEFs) can be focused on tumors for local killing. As well as the possibility of utilizing the CANCAN (canceled bipolar) effect to...

High voltage nanosecond pulse generator(HVNPG) with compactness and repetition frequency has become a vital demand in some fields. In this paper, the principle of inductive energy storage(IES) is applied to twisted pair wire(TPW), served as energy storage unit for generating nanosecond pulse. As a kind of transmission line, the electromagnetic fiel...

For the application process of high voltage pulse generators, the problem of the stray inductance of the loop is often unavoidable, which severely limits the rise time of the pulse. Aimed at this problem, a bipolar pulse rising edge steepening circuit (BPRESC) topology is proposed in this paper. BPRESC is based on the diode reverse recovery and wor...

Progress of wide-bandgap semiconductor devices has promoted the development of pulsed power switches to miniaturization, high power and high repetitive frequency. The miniaturization and high power of switches means that the chip and its surroundings face the challenge of high voltage tolerance in a small space inevitably. Therefore, the potential...

The measurement of square wave signals with sub-nanosecond (<1 ns) front challenges in terms of achieving a high cut-off frequency, a high attenuation ratio, and wideband characteristics. In this article, we propose a high-resistance matching circuit for pulse measurement. Additionally, we develop a prototype self-integrating capacitive voltage div...

As the applications of pulse generators continue to develop in a variety of fields, so do the requirements for pulse generators. The development of pulse generators is facing many key issues, such as high-voltage drive isolation, compact design, and weight reduction. In this regard, a single-driver Marx generator (SDMG) based on series-connected sw...

Winding short-circuit (SC) faults are a prevalent issue in synchronous machines, and the accurate and timely identification of these faults is critical for maintaining power system stability. Current methods for inspecting synchronous machine windings often rely on periodic inspections based on human expertise. Numerous studies have explored the ap...

With the increasingly extensive applications of all solid-state Marx generators in the defense and industrial fields, the development of traditional Marx topology faces many key issues, such as drive isolation, compact design, and slow discharge falling edge over high resistance. Hence, a novel compact quasi-square wave pulse generator is proposed....

Marx circuit is widely used in pulse-generating devices. However, in practical applications, the discharge loop of the Marx often includes stray capacitance and inductance, which can cause oscillations at the leading edge of the pulse. This article proposes an resistor-capacitor-diode (RCD) snubber circuit connected to the load in parallel to suppr...

Nanosecond pulse electric field (ns-PFE) can target the organelles in cells, which can induce tumor cell apoptosis. This interesting electrophysiological effect implies that it is possible to inhibit tumor recurrence and metastasis. Due to the anisotropy of biological tissue, higher requirements are put forward for the output impedance regulation a...

This work suggests applying chamfering treatment to the plasma generator of the empty electrode structure. Enhancing the electrodes’ physical structure can significantly improve plasma characteristics without requiring intricate control systems. Experiments have shown that changes in the electrode’s shape can lead to changes in the formation of the...

The reactive species-independent nature of cold plasma's electric field is pivotal in biomedical applications. This work proposes to connect the plasma fluid model and the asymptotic Smoluchowski model for electroporation, providing a unified framework to investigate the evolution of the electric field in the biological substrate and the multi-stag...

In order to solve problems, such as the nonadjustable drive pulsewidth of semiconductor lasers, in this article, an all-solid-state modular pulse current generator (PCG) topology based on a coupling inductor is proposed. Each stage of the PCG consists of one inductor, two switches, and a diode. The inductors are charged in series and discharged par...

In the irreversible electroporation (IRE) therapy, the absorbed energy is normally characterized as the applied dose and assumed to be distributed in the homogeneous dielectric. By employing statistical analyses, we have studied the absorbed energy distribution in the porous multicellular dielectric, with the geometric patterns randomly generated f...

In order to meet the demands of fast rise times, short pulsewidth, and high repetition frequency and enhance the output current level of the Marx pulse generator for high-power pulse applications, this article proposes a pulse generating technique based on parallel SiC MOSFETs. The magnetic induction current balance (MICB) method is employed to eff...

In recent years, pulsed magnetic field (PMF) have attracted significant attention as a non-invasive electroporation method in the biomedical field. To further explore the biomedical effects generated by oscillating PMF, we designed a novel PMF generator for biomedical research. Based on resonance principles, the designed generator outputs sinusoida...

Irreversible electroporation (IRE) has emerged as a promising modality for tumor ablation, leveraging the controlled application of electrical pulses to induce cell death. However, the associated muscle contractions during the procedure pose challenges. This study introduces a novel approach, termed Synergistic Bipolar Irreversible Electroporation...

In the article, a new type boost high‐voltage nanosecond pulse generator is proposed. The distributed inductance of the transmission line is utilised as the energy storage unit and cooperated with the variable impedance transmission line transformer to generate nanosecond pulses with extremely high‐voltage gain. What’s more, the isolation effect ca...

In many applications of Marx generators, it is very common to introduce additional stray inductance caused by lengthened leads. It will cause the problem of slowing down the rising edge of the pulse, which will greatly limit the generation of short pulsewidth and fast edge pulses. To solve this problem, this article proposes a pulse rising edge ste...

Insulation power supply (IPS) for multiple switches is a key issue for solid-state pulse generators (SSPG). The existing parallel structure for IPS is short of insulation similarity, which results in low insulation utilization ratio (IUR) and limited adjustability. Here we propose a power supply chain (PSC) with series insulation structure. The ins...

As an emerging technology in liquid inactivation, one of the main challenges of pulsed electric fields (PEFs) inactivation lies in quantitatively describing and predicting its lethality to microorganisms. However, due to its cross-scaled complexity and the consequent numerous regulatory factors, there is currently still no unified framework to unde...

From the microscopic electroporation to the irregular distribution of cell populations, the inactivation efficacy of pulsed electric fields (PEFs) from in vitro experiments has lacked a unified physical model due to its cross-scale complexity. Inspired by a coarse-grained approach from the percolation theory, the inactivation process is simulated f...

The proposal of a new waveform of nano-microsecond synergistic pulsed electric field introduces a promising research direction for enhancing the therapeutic efficacy of traditional irreversible electroporation ablation. However, the investigation of parameter effects in the new synergistic pulsed tumor ablation technology is still in its early stag...

The biological response to short pulses with a width on the order of ten nanoseconds is still blur for lacking of a dependable high-voltage ultrashort pulse power module (HVUPPM). Therefore, this paper introduces a HVUPPM with high output/input voltage gain and high repetition rates. Firstly, the proposed HVUPPM utilizes a short-circuit secondary s...

Unlabelled: The H-FIRE (high-frequency irreversible electroporation) protocol employs high-frequency bipolar pulses (HFBPs) with a width of ∼1 μs for tumor ablation with slight muscle contraction. However, H-FIRE pulses need a higher electric field to generate a sufficient ablation effect, which may cause undesirable thermal damage. Objective: R...

In this work, we proposed nµPEF, a novel pulse configuration combining nanosecond and microsecond pulses (nµPEF), to enhance tumor ablation in irreversible electroporation (IRE) for oncological therapy. nµPEF demonstrated improved efficacy in inducing immunogenic cell death, positioning it as a potential candidate for next‐generation ablative thera...

Precise control of cargo release is essential but still a great challenge for any drug delivery system. Irreversible electroporation (IRE), utilizing short high-voltage pulsed electric fields to destabilize the biological membrane, has been recently approved as a non-thermal technique for tumor ablation without destroying the integrity of adjacent...

Hybrid switches combining shunt silicon (Si) insulated-gate bipolar transistors (IGBTs) and silicon carbide (SiC) metal-oxide semiconductor field-effect transistors (MOSFET) offer advantages of low losses, cost-effectiveness, and fast switching speed. Nevertheless, the restricted hybrid switching voltage level hinders the wide application of this e...

Insufficient surface insulation margin is the primary challenge for a 10 kV plus high-voltage semiconductor module. Surface charge accumulation and electric field distortion are the leading causes of surface insulation failure. Power modules restrict leakage loss, so only insulation dielectrics with low surface conductivity can be used. However, lo...

To explore the application of pulsed current in biomedicine, an all-solid-state rectangular pulse current generator (RCPG) is proposed. The RCPG uses a field programmable gate array (FPGA) as the control system and a solid-state semiconductor switching metal–oxide–semiconductor field-effect transistor (MOSFET) as the control switch. The RCPG is mod...

Shorter voltage and current rise/fall time are the main driving forces for nanosecond pulse power technology. The switching capabilities of SiC-MOSFET directly determine the dynamic characteristics of most solid-state pulse topologies. The core to explore the dynamic performance potential of SiC-MOSFET is the ultrafast gate driver with a high insta...

To meet the demand for bipolar high-voltage pulse out in the food sterilization field, an all-solid-state bipolar Marx pulse generator (BMPG) based on magnetic isolation is developed. The drive circuit uses the magnetic core to transmit the control signal and power simultaneously. It adopts the stacking of the magnetic core and the reverse parallel...

In order to explore the bioelectric effect of high-voltage extremely short pulse electric fields (esPEFs) on tumor cells, first, based on the finite element platform, a spherical single-cell Multiphysics model was established. Both electroporation and dielectric relaxation of the membrane are considered. The electroporation effects and Maxwell stre...

The effect of high voltage pulsed electric field on the electroporation of plant and animal cells has been widely used in tumor ablation, food sterilization, and biodiesel extraction, but the effect of pulsed electric field on pathogenic virus without intact cell structure has not been effectively studied. In this paper, we conducted a preliminary...

High-voltage ultrashort pulse (HVUSP) is attaching more attention to advanced biomedicine. In this paper, a capacitive chopping circuit (CCC) topology with all-solid-state switches is proposed, which can generate adjustable HVUSP with high power efficiency. Dual capacitors of opposite polarity are connected in series with the load, thus cutting off...

There is no doubt that transformer plays a fundamental role in power system. At the same time, transformer winding fault diagnosis is an important topic. Many works put the most emphasis on the identification of fault type and degree, while ignoring the fault location. However, fault location is an urgent problem to be solved, which is worth studyi...

In order to explore the bioelectric effect of 5 ns pulsed electric fields on tumor cells, a spherical single-cell multiphysics model was first established based on the finite element simulation platform. In consideration of the dielectric relaxation of the biological plasma membrane under the high-frequency electric fields, the electroporation and...

Ultrawideband electromagnetic pulses have sub-nanosecond rise time and repetition frequency above 100 kHz. Ultrawideband characteristics make it increasingly used in biomedical, intentional electromagnetic interference, and other fields. Avalanche Marx circuits are an important way to generate high-voltage sub-nanosecond pulses with high repetition...

The surface charge accumulation on polymers often leads to surface flashover. Current solutions are mainly based on the introduction of inorganic fillers. The high-cost process and low compatibility remain formidable challenges. Moreover, existing researches on all-organic insulation focus on capturing electrons, contrary to alleviating charge accu...

Gas discharge in heterogeneous porous dielectric (PD) is becoming a reliable and popular low-temperature plasma technique in surface modification and plasma catalysis. However, the exact breakdown characteristics in the porous dielectric are not well studied due to experimental and diagnostic limitations. In this paper, a fluid model is then used t...

This paper presents a new type of all solid state boost Marx pulse generator (BMPG). On the basis of the classic pulse forming Marx circuit, without changing the voltage level of each voltage module, a new switch is added for the isolated inductor energy storage and recovery, so as to realize the output of high-voltage nanosecond pulses. At the sam...

All-solid-state switches are one of the core components of pulsed power supply systems. However, the voltage level of a single switch is limited. By optimizing the chip structure, the voltage level of a single switch can be improved. Due to the immaturity of the production process and the positive correlation between the blocking voltage and the on...

Hundreds of high frequency bipolar pulse bursts with ∼1 μs have been suggested to alleviate muscle contractions and pain during the irreversible electroporation (IRE) tumor treatment. This study is performed to verify whether eight bursts of high frequency reversible electroporation pulses (HFREs) with bleomycin could be used for electrochemotherap...

Better electrical insulation and thermal management are both urgently required in integrated power semiconductors. Electrical insulation epoxy encapsulation suffers from poor heat conduction, which has increasingly become a bottleneck of power semiconductors integration. Although incorporating high thermal conductivity ceramics, such as hexagonal b...

Irreversible electroporation (IRE) by high-strength electric pulses is a biomedical technique that has been effectively used for minimally invasive tumor therapy while maintaining the functionality of adjacent important tissues, such as blood vessels and nerves. In general, pulse delivery using needle electrodes can create a reversible electroporat...

In order to meet the requirements of high voltage, high power, and compactness for pulse generators used in the field of liquid food sterilization, an all-solid-state Marx generator based on a novel magnetic isolated drive is proposed. The drive circuit uses the magnetic core to transfer the control signal, which adopts core stacking and inverse pa...

The tumor treatment field imposes a low intensity (1–3 V/cm) intermediate frequency (100 kHz–500 kHz) alternating electric field on the tumor cells to destroy the normal mitotic process of tumor cells, thereby inhibiting the proliferation of tumor cells. Clinically, it has been shown that the tumor treatment field can effectively slow down the grow...

Low-intensity pulsed ultrasound (LIPUS) can kill tumor cells non-invasively by acting on human tissues with millimeter-level precision. However, the physical and biological killing mechanisms of low-intensity pulsed ultrasound on tumor cells are still unclear. In this study, we rationally set up the electric pulse to stimulate the ultrasonic transd...

In this paper, an air-isolated module with adjustable insulation based on magnetic coupling resonance is proposed for high-voltage pulse generators. The insulation level can be adjusted rapidly over a wide range by changing the air gap. By virtue of invariable dielectric properties of air, the module can avoid electrical aging and reduce the risk o...

The reliable operating state of smart electricity meters is significant in industrial applications. Faulty meters or meters in a poor measurement state will seriously impact both customers and stakeholders. However, the maintenance personnel now still use the manually periodic sampling inspection from the batch of smart electricity meters to evalua...

Electroporation achieved by the application of pulsed electric field is successfully used for clinical tumor ablation. Electrochemotherapy (ECT) and irreversible electroporation (IRE), which are two protocols based on electroporation, have been shown to ablate only tumor cells while preserving the function of normal blood vessels. However, the mech...

Cell electrofusion technology is usually performed by short-term high-voltage electrical pulses with a duration of microseconds to induce cell electroporation. However, exposure to high amplitude microsecond pulses can easily lead to excessive cell electroporation while promoting cell electrofusion, resulting in the death of the fused cells, thereb...

Frequency response analysis (FRA) has been accepted as a widely used tool for the power industry. The interpretation of FRA can be achieved by the conventional mathematical indicators-based method, which is mostly used in the past. The newly developing artificial intelligence (AI)-based method also provides an alternative interpretation. However, i...

Nanosecond pulsed electric fields (nsPEFs) may induce differential effects on tumor cells from different disease stages and could be suitable for treating tumors by preferentially targeting the late-stage/highly aggressive tumor cells. In this study, we investigated the nsPEF responses of mouse ovarian surface epithelial (MOSE) cells representing p...

Frequency response analysis (FRA) is a popular tool to detect transformer winding deformation faults. It has been recently used to diagnose the winding inter-turn short circuit fault of the electric machine. The application of FRA is based on the fact that the winding can be equivalent to an electrical circuit consisting of resistance, inductance,...

SiC-MOSFET has been widely used in nanosecond pulse power generators due to its excellent switching characteristics. The solid-state Marx generator using SiC-MOSFET has the advantages of modularity, flexible adjustment, and economic reliability. However, due to the limitation of the busbar loop’s parasitic inductance, the excellent switching charac...

Better thermal management is urgently required in the electronics industry. Ceramic fillers are widely used in electronic polymer packages due to their high thermal conductivity and electrical insulation properties. The interface between the fillers and matrix is usually the weakest point in the heating circuit of composites. Many modification meth...

The nanosecond short pulse generator, which operates continuously at MHz repetition rates, plays an important role in high-energy accelerators, pulsed laser modulation, electromagnetic biological effects and other fields. Pulse-forming lines based on gas spark gap are the main means to generate high-voltage nanosecond short pulses, but due to elect...

High-frequency bipolar high-voltage pulsed electric field can be used in tumor ablation to uniform the electric field distribution in the ablated region and inhibit muscle contraction effectively. Developing a high-frequency bipolar pulsed power generator (HBPPG) with wide range of specifications such as voltage magnitude, waveform, repetition rate...

Chemoresistance causes tumor recurrence and metastasis, resulting in poor clinical outcomes and low survival, and has been considered an obstacle to tumor therapy. The development of novel therapeutic approaches that can effectively kill chemoresistant tumor cells (CRTCs) is therefore critical to overcoming these obstacles. Objective: Here, we in...

Irreversible electroporation (IRE) is a minimally invasive tumor therapy using pulsed electric field with high intensity while the important tissues such as blood vessel, bile duct, and nerve are preserved. In addition to ablation area, reversible electroporation (RE) region is also generated using needle electrodes for pulse delivery. The goal of...

Picosecond pulse electrical fields (psPEFs), due to their high temporal-resolution accuracy and localization, were viewed as a potential targeted and noninvasive method for neuromodulation. However, few studies have reported psPEFs regulating neuronal activity in vivo. In this paper, a preliminary study on psPEFs regulating action potentials in hip...

This article presents a new method for forming nanosecond short pulse on high impedance load using the turnon and turn-off delays of dual Marx. The generator combines advantages of the traditional solid-state Marx generator's modular stacking design to easily stack high-voltage pulse, flexible pulsewidth, and compact size. It can output unipolar or...

The present study aimed to investigate the influence of discharge current frequency on the deformation of aluminum alloy plates, jet, and welding effects. A modular EMPW system was designed and developed to carry out the welding of the aluminum alloy plate and copper plate. The system consists of four 14 kJ pulse power modules (PPMs), and the worki...

Since the power transformers are indispensable in power systems, their reliable operation are of significance. Winding deformation is one of the most common failures within transformers. At present, many methodologies have been proposed to detect these faults, and frequency response analysis (FRA) technique is most frequently used because of its lo...

Electromagnetic pulse welding (EMPW) is of increasing interest for industrial applications because of its advantages in dissimilar metals welding. During the EMPW process, the flyer plate is driven by the Lorentz force to impact the parent plate. The dynamic behavior of the flyer plate has been investigated in this work, based on the 3D finite elem...

A modular solid‐state pulse generator based on a multi‐turn linear transformer driver (LTD) is designed for the application of pulse power techniques with a high voltage, large current and wide pulse width. The LTD adopts the method of multi‐turn winding on the magnetic core, which can help to output pulses of wide width. The isolation of the power...

Winding deformation is a common problem that takes place within operating power transformers due to various internal and external conditions. Due to their progressive nature, winding deformations should be detected and rectified as soon as they emerge. Unfortunately, the only reliable technique to detect such faults at this stage is the frequency r...

Nanosecond pulse output at MHz level is widely concerned, because of its potential application in the experiment of cell function electric field regulation and accelerator electron gun injector. In this paper, a pulse generator based on the combination of the Blumlein pulse forming line and the boost method is proposed. Different from the tradition...

The discriminating effects of nanosecond pulsed electric fields (nsPEFs) between chemoresistant tumor cells (CRTCs) and their respective homologous chemosensitive tumor cells (CSTCs) were investigated based on bioimpedance spectroscopy (BIS). The electrical properties of individual untreated cells were determined by fitting the impedance spectra to...

When delivered across a cell, certain pulsed electric fields can cause an increase in the cell membrane permeability through a biophysical process known as electroporation. The current signals during the electric pulses could be used as a method for noninvasive electroporation measurement because of the sharp change in the conductivity of cells due...

Electromagnetic pulse welding (EMPW) is an environmentally friendly and advanced manufacturing technology. Researches find the macro-morphology of EMPW joint of sheets presents a multilayer ellipse. The EMPW experiments of Al-Cu sheets and Al-Mg sheets were carried out, both the macro-morphology and the micro-morphology showed there were collision...

Pulsed electric field treatment modalities typically utilize multiple pulses to permeabilize biological tissue. This electroporation process induces conductivity changes in the tissue, which are indicative of the extent of electroporation. In this study, we characterized the electroporation-induced conductivity changes using all treatment pulses in...

In order to accurately study the distribution of cell transmembrane potential under nanosecond pulses electric field(nsPEF), we developed a five-layer dielectric model of spherical cell with multi-physics simulation software of COMSOL Multiphysics, and studied the bioelectric effects of dispersion(DP) and electroporation(EP) on a cell with nsPEF. C...

The simulation of DC ageing evolution in insulating polymers is of an important significance in promoting the development of computational high voltage engineering (CHVE) both for theoretical understanding and practical application. We propose a numerical model of ageing with the finite difference grid in the two-dimension coordinate which is progr...

The accurate and fast diagnosis of transformer winding deformation faults is of significance to power suppliers and utilities. An improved winding mechanical deformation fault classification method is proposed. In this study, the transformer frequency response data is used to draw polar plots, and then its texture features are extracted for fault c...

The long-term performance of cable insulation has been severely challenged [1-3] by the technological advances of high voltage DC (HVDC) power lines for bulk long-distance subsea or underground transmission worldwide [4-8]. In particular, its life plays an important role in the reliability of the whole transmission system, which has received a grea...

The decrease in killing sensitivity of the cell membrane to microsecond pulse electric fields (μs-PEFs) is ascribed mainly to the aberrant morphology of cancer cells, with clear statistical correlations observed between cell size and shape defects and the worsening of the electrical response to the PEF. In this paper, nanosecond pulsed electric fie...