Voltage IGBT Research Articles

Multi-Level Synthesis Gate Voltage Active Control Technology for Optimizing IGBT Switching Characteristics

Compared with the conducting and blocking steady-state processes, the voltage and current stress of IGBT become very higher in the turning-on and turning-off transient processes, and the instantaneous power loss increases significantly. The switching transient conditions greatly affect the reliability and stability of IGBT device and power converter. During the IGBT turning on process, the reverse recovery of the symmetrical bridge arm anti paralleled diode can cause additional turn-on loss and current peak overshoot. The gate voltage active control technology can effectively suppress current spike and reduce turn-on loss in the period from the initial opening time to Miller platform. The multilevel synthesis technology can adjust the gate voltage waveform and produce depression or bulge in the normal driving voltage waveform for a certain time. In this paper, the sensitive parameters of gate voltage active control, which affect the current overshoot, and turn-on loss of IGBT are studied based on the theoretical calculation and mathematical model. A multi-level synthesis gate voltage active control technology is proposed according to the principle of gate voltage active control. The relationship among the acting voltage amplitude, execution time, current peak and switching loss is studied. Considering the actual application conditions, the optimized active control scheme of gate voltage is designed. Finally, the switching characteristics test is carried out, the results verify that the proposed control technology can effectively reduce the current overshoot and turn-on loss in comparison with the conventional schemes.

Maximizing Efficiency in Smart Adjustable DC Link Powertrains with IGBTs and SiC MOSFETs via Optimized DC-Link Voltage Control

In recent years, the push towards electrifying transportation has gained significant traction, with battery-electric vehicles (BEVs) emerging as a viable alternative. However, the widespread adoption of BEVs faces multiple challenges, such as limited driving range, making powertrain efficiency improvements crucial. One approach to improve powertrain energy efficiency is to adjust the DC-link voltage using a DC-DC converter between the battery and inverter. Here, it is necessary to address the losses introduced by the DC-DC converter. This paper presents a dynamic programming approach to optimize the DC-link voltage, taking into account the battery terminal voltage variation and its impact on the overall powertrain losses. We also examine the energy efficiency gains of IGBT-based and silicon carbide (SiC) MOSFET-based adjustable DC-link voltage powertrains during WLTC driving cycles through PLECS and Matlab/Simulink simulations. The findings indicate that both IGBT and MOSFET-based adjustable DC-link voltage powertrains can enhance the WLTC drive-cycle efficiency up to 2.51% and 3.25% compared to conventional IGBT and MOSFET-based powertrains, respectively.

Characteristics and Identification of Partial Discharge for Insulation Structures in High Voltage IGBT Modules Under Positive Square Wave Voltage

Characteristics and Identification of Partial Discharge for Insulation Structures in High Voltage IGBT Modules Under Positive Square Wave Voltage

Low On-State Voltage and EMI Noise 4H-SiC IGBT With Self-Biased Split-Gate pMOS

A 15-kV-scale 4H-SiC insulated-gate bipolar transistor (IGBT) with a self-biased split-gate pMOS (SGPMOS) is proposed and simulated in this work. By introducing the SGPMOS, the proposed IGBT forms a hole barrier in the ON-state and a hole extraction path during the turn-on and turn-off transient, respectively. Compared to GS IGBT, the ON-state voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {ON}}{)}$ </tex-math></inline-formula> of the SGPMOS IGBT is decreased by 54.95% for the same turn-off loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {off}}$ </tex-math></inline-formula> ). Meanwhile, compared with pMOS IGBT, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> and gate charge ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${Q}_{g}{)}$ </tex-math></inline-formula> characteristics exhibit that the Miller capacitance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}_{\text {gc}}{)}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${Q}_{g}$ </tex-math></inline-formula> of the SGPMOS IGBT are reduced by 56.60% and 35.85%, respectively. Moreover, SGPMOS can extract the hole accumulated both under the gate oxide and in the P-shield region during the turn-on transient. This diminishes reverse displacement current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{G\_{}{\text {dis}}}{)}$ </tex-math></inline-formula> , contributing to low electromagnetic interference (EMI) noise. Simulation results demonstrate that, compared to pMOS IGBT, the SGPMOS IGBT achieves better controllability in peak turn-on current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {max}}{)}$ </tex-math></inline-formula> and turn-on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{d}{I}_{C}/\text{d}{t}$ </tex-math></inline-formula> , featuring a 52.75% lower maximum reverse recovery <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{d}{V}_{\text {KA}}/\text{d}{t}$ </tex-math></inline-formula> for the same turn-on loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {on}}{)}$ </tex-math></inline-formula> .

Study on avalanche ruggedness of high voltage IGBTs

With the increase of IGBT voltage and current ratings, the avalanche effect has become an important factor limiting the safe operating area (SOA) of the device. The hole injection of the p+n junction on the back of the device when the avalanche effect occurs is the main feature that distinguishes the avalanche effect of the IGBT from other devices. In this paper, the avalanche breakdown characteristics of IGBT and the behavior of avalanche-generated current filaments are studied through theoretical analysis and numerical simulation, and the physical mechanism dominating the behavior of avalanche-generated current filaments is revealed. The results show that the hole injection on the backside of IGBT leads to an additional negative differential resistance branch on the avalanche breakdown curve, and the strength of the negative differential resistance effect depends on the common base current gain of IGBT α&lt;sub&gt;pnp&lt;/sub&gt;. With the increase of α&lt;sub&gt;pnp&lt;/sub&gt;, the negative differential resistance effect becomes stronger, the avalanche current at the valley point where the additional negative differential resistance branch transforms into the positive differential resistance branch also becomes higher. And the valley point at the avalanche breakdown curve of IGBT dominates the strength of the avalanche-generated filament. As a result, the strength of avalanche-generated filament depends on the α&lt;sub&gt;pnp&lt;/sub&gt;. With the lattice temperature increasing, the avalanche breakdown voltage of IGBT increases, leading to the shifting of the avalanche breakdown curve towards a higher voltage. And with the increase of α&lt;sub&gt;pnp&lt;/sub&gt;, the offset of the avalanche breakdown curves at high and low temperature becomes smaller, which dominates the lateral movement speed of the avalanche-generated filament. With the increase of the α&lt;sub&gt;pnp&lt;/sub&gt; and the decrease of the offset of avalanche breakdown curves at high and low temperature, the avalanche-generated filament laterally moves more slowly. To sum up, with the increase of the α&lt;sub&gt;pnp&lt;/sub&gt; of IGBT, the avalanche-generated filament becomes stronger and moves more slowly, which extremely causes the local overheating where the filaments exist and lowers the avalanche robustness of the device. Therefore, the α&lt;sub&gt;pnp&lt;/sub&gt; of IGBT must be controlled precisely in order to have a good trade-off between the characteristics and the reliability of IGBT.

Prediction of Hybrid Wind Farms using Fuzzy TOPSIS Analysis

In this paper Hybrid air turbines One way to set up, Battery energy saving With systems (BESS)Is to increase the turbines. In such windmills Caused by the speed of the wind By contrast, the price of BESS Increases and battery Life expectancy decreases. BESS Fitted hybrid Operation of the wind mill to reduce costs Awareness management this paper proposes the technique. In the calculation of wind speed considering the error in Battery charging and Discharge forces are diagnosed. This investigation is a windmill three different for the farm considering the conditions. Battery operating cost and Life cycle number Temperature to estimate and of exhaust changes when calculating the depth aging for lead-acid battery the model used. Overhead lines Large coastline using To connect the windmills, HVDC Became flexible control And advanced computer Stability and up to 600 km For sending over Significant at low cost Provides benefits .Will use IGBT Voltage Source Converter (VSC) Based HVDC system Wind turbines Optional DC to connect Technically widespread Accepted, because In its independent active And reactive power control, Flexible AC system Control and support For marine wind farms Important. The purpose of this study of fuzzy TOPSIS systems General of development is to provide perspective. We have a literary review starting and making decisions Used in the field various obscure patterns Lets explore. Finally, some of the obscure topsides Applications We provide. Supply chain, Environment, energy sources, Such as trade and health in the application areas Distributed and Classified. Obscure other associated with TOPSIS Methods, Vague TOPSIS Processes, ambiguous Packages, hesitant vague Packages or intuition Obscure packages, Ambiguous analysis step Process (AHP) or Team decision-making improvements by such attitudes are explored and compared. Many alternatives and Criteria are used. Finally, current trends, the most popular approaches and insight into directions. we are taking this End user view, Frequency of running, Ease of fixing Errors, Time of fault detection are alternatives. Evaluation, Incremental Integration, Top Down integration testing, sandwich, Big bang, End to End testing Frequency of running parameter. Alternative: Incremental Integration, Top Down integration testing, sandwich, Big bang, End to End testing. Evaluation Preference: End user view, Frequency of running the tests, Ease of fixing Errors, Time of fault detection. In this form of analysis, the TOPSIS method is the most ideal Short-distance solution and negative-best The solution with the longest distance from the solution Determines, but the comparison of these distances Does not consider importance. From the result it is seen that End to End testing is got the first rank whereas is the sandwich is having the lowest rank.

A Novel Local Voltage Sensing Mode for High Voltage IGBT Sensor

Collector-emitter voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> ) detection of insulated gate bipolar transistors (IGBTs) is important for safety-critical and mission-critical power applications. The conventional voltage sensing method is characterized by the detection range from 0 V to the rated voltage in the application ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ), which is limited by the contradiction between the dynamic range of the signal and the ADC resolution in high voltage situations. This letter proposes a novel local voltage sensing (LVS) mode, in which the detection range is from <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sub> to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> , where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sub> is a controllable starting point for the sensed voltage. Based on the LVS mode, a novel controllable voltage sensor structure is given, which can provide a sensing signal that is a scaled version of the large <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> when <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> ≥ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sub> . <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sub> can be controlled by applying a negative voltage to a control electrode gate ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G2</sub> ). An analytical model is derived to understand the mechanism of the sensor and simplify the design. The effects of internal and external parameters on the sensing characteristics are simulated using Medici & TS4. Furthermore, the sensor is incorporated into a prototype 1200-V IGBT. The test results show that, under the condition of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G2</sub> = 0 V or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G2</sub> = −1 V, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sub> and nonlinear error are 622 V and 3.9% or 708 V and 3.4%, respectively, and the experimental data agree with the analytical model results. Finally, an application of dc-bus voltage monitoring using the LVS mode is presented.

In Situ Junction Temperature Monitoring and Bond Wire Detecting Method Based on IGBT and FWD on-State Voltage Drops

Junction temperature monitoring and bond wire detection are crucial for the condition monitoring and protection of insulated gate bipolar transistor (IGBT) and freewheeling diode (FWD). <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drop is one of the most popular parameters for junction temperature estimation and bond wire detection. However, there is still a lack of cost-effective <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drop measuring techniques for both IGBT and FWD with a fast response. This article proposes an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> junction temperature monitoring and bond wire detecting method based on IGBT and FWD <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drops. The proposed technique can measure the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drops of IGBT and FWD online with high accuracy and fast response. The <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drops of IGBT and FWD under low load current are linearly dependent on their junction temperatures. Besides, the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drops under high load current are closely related to the bond wire degradation. Therefore, the junction temperatures and bond wire conditions of both IGBT and FWD can be monitored based on the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drops during a period of alternating current. The experiment results validate the feasibility of the proposed <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -state voltage drop-based method for junction temperature monitoring and bond wire detecting. The proposed method has characteristics of high response speed, noninvasiveness for normal converter operating, and simple structure.

An Offline Parameter Self-Learning Method Considering Inverter Nonlinearity With Zero-Axis Voltage

In the voltage source inverter applications, inverter nonlinearities would affect the parameter identification process in many ways. Hence, this article proposes an offline identification method for resistance and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis inductance surface by considering the inverter nonlinearity characteristics. A variable amplitude square-wave injection (VASI) scheme is proposed for the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis inductance identification. The VASI method achieves the inductance identification with a novel data sampling strategy. Meanwhile, it can also establish the inductance surfaces by only a few identified data points with a polynomial fitting algorithm, which greatly reduces the identification time compared with the existing methods. The resistance identification is realized by a slope signal injection method, in which the effect of IGBT voltage drop is analyzed. In order to improve the identification accuracy, the inverter nonlinearities are compensated by a self-learning method considering the zero-axis voltage at different rotor positions. At the same time, the sampling error in zero current zones of abc-phases is researched. In order to verify the effectiveness and generality, the proposed method is carried out on two different test machines and confirmed by finite element analysis.

The three-level inverter topologies analysis for application by electric centrifugal pump units

In the article, the schemes for providing AC power with frequency conversion for the induction submersible electric drive of oil production units are analyzed. The electric submersible drive is widely used and has stringent efficiency requirements, so this research is relevant. The centrifugal pump units are composed of a low-voltage power source, a frequency converter, a step-up transformer, a cable line, an electric drive and a centrifugal pump. This article discusses options for replacing the step-up transformer and two-level voltage / frequency converter with a three-level flying capacitor converter (FCC) or a three-level clamping diode converter (NPC). The expected states of the power high voltage IGBT modules are described. The waveforms of the inverter output voltage and the submersible induction motor stator voltage in different circuits are shown. A voltage levels analysis for each module is done, the electric drive starting time change is estimated, the total harmonic distortions (THD) are calculated, and a 1.1% THD reduction by applying the NPC circuit is shown. The harmonic current spectrum for each circuit is presented.

Research on Coordinated Control of Dual Motors Based on DSP

In order to save energy and reduce emissions, improve the ecological environment and achieve sustainable development, the research and development of electric vehicles has become a common consensus in all countries in the world. As the core component of electric vehicles, the requirements for drive motors are getting higher and higher. The control strategy of the dual-stator motor is based on the mature vector control method of the traditional PMSM. The two sets of three-phase windings are transformed at the same time by rotating coordinate, and the vector control under the dual synchronous rotating coordinate is realized through separate decoupling; the control system uses TMS320F28335 as the control core, equipped with The dual stator motor vector control system makes full use of chip resources to realize the functions of rotor position detection, two-winding current and voltage acquisition and IGBT drive at the same time to complete the torque control of the two stator windings. It is verified by experiments that the control system meets the requirements of electric vehicle power system, with simple structure and strong practicability.

Performance investigation of stand-alone induction generator based on STATCOM for wind power application

Self-Excited induction generators (SEIG) display a low voltage and frequency regulation due to variable applied load and input rotation speed. Current work presents a simulation and performance analysis of a three-phase wind-driven, SEIG connect to a three-phase load. In addition, an investigation of the dynamic operation of the induction generator from starting steady state until no-load operation. It is assumed that the input mechanical power is constant where the rotor of the SEIG rotates at a constant speed. The value of the excitation capacitance which is necessary to the operation of the induction generator also computed to ensure a smooth and self-excitation starting. The output voltage of the generator is adjusted by varying the reactive power injected by STATCOM. A 3-phase IGBT voltage source inverter with a fuel cell input supply is connected as STATCOM which is used to compensate for the reduction in the supply voltage and its frequency due to variation occurred in the applied loads. This work includes introducing a neuro-fuzzyy logic controller to enhance the performance of the SEIG by regulation the generated voltage and frequency The dynamic model of SEIG with STATCOM and loads are implemented using MATLAB/SIMULINK

Modelling of DVR with Artificial Intelligence for Compensate the Voltage Sag, Swell and Flickers by Using SVPWM Switching Techniques in Distribution Lines

In this research proposes FLC and Artificial Neural Network (ANN) based on Dyanamic Voltage Controller (DVR) along with d q o transformation for power qulity improvement in a distribution system. Design a 9levels CHMLI based on Custom Power device with SVPWM techniques. Distribution needs to protect against the harmonics such as sag, swell and flickers are affect on standard pure power supply at the end of the load. These power quality issues are minimised with voltage injection using DVR.The designed inveter to reduced the voltage switching losses and stresses of semiconductor devices. Here used single DC voltage source with a series connection of 4 capacitors for self balancing purpose, 3 diodes,output voltage levels and Cascaded H-bridge cell. the proposed 9 level CHMLI inverter citcuit to helps reducing the number of independent voltage dc sources and IGBTS. The harmonics are less in the output voltage proposed work (new topologies)compared to conventional topology. A comparision of FLC and ANN with THD and Power Factor results and study. It has been carried out to analyse through MATLAB / SIMULINK Software.

Review on Laminated Busbars used in High Frequency Inverters

Improvement in the efficiency and cost in the high frequency inverter will play a major role in its applications like electrical vehicles (EV). A high voltage IGBTs are used in inverters to bear the voltage peaks across the IGBT switch at the turning off period of switch. By decreasing the value of voltage peak, can reduce the voltage rating of IGBT switch, by which the system cost will decrease. Decreasing the value of voltage peak can be achieved by decreasing the inductance of the inverter circuit which includes turned on switch inductance, DC link capacitors inductance and connecting wires inductance. By replacing the connecting wires with a laminated busbar in an inverter, the inductance value of a connecting wires can be reduced. Laminated bus bar is a parallel conductor plates separated by a dielectric medium. Upper plate is considered as positive plate and lower plate is a negative plate. In this paper it gives a detailed information about laminated busbar with different designs, using different conductive materials, their calculated inductance in ANSYS 3D FEM software and concluding with suitable laminated busbar for high frequency inverter.

Event Driven Control of Voltage and Current Gradients of Medium Voltage IGBTs

Medium voltage insulated gate bipolar transistors are fast switching devices that require low gate drive power. They inherently generate high voltage and current gradients during switching transitions. These are generally limited by retarding the changes of the gate charge. Additional gate resistors are usually installed for this purpose. The drawback is high switching losses. A novel method is described in this article that aims at controlling the voltage and current gradients during switching transitions. The gate charge of the input MOS device is controlled by injected gate currents. These follow particular command functions that are predefined and stored in a memory. The method requires reacting within microseconds, which traditional closed-loop control cannot do. Specific time events are therefore defined to trigger the respective command function. These functions depend on the instantaneous values of the collector current or the collector–emitter voltage, variables that are identified without delay, knowing their predefined gradients and counting the time from the respective event to reach their final values. Experimental results show the performance of event driven control. Low current and voltage gradients are enforced while the switching losses are reduced.

Deep Trench Termination Structure with p-Type SiC Layer for Improved Reliability of High Voltage IGBT

A 3.3 kV rated Si-SiC hybrid IGBT with Si-based active structure and Si/SiC composite junction edge termination is proposed in this paper. A single deep and wide Si trench, capped with a hetero-epitaxially grown SiC layer, is employed as the edge termination structure. Therefore, the active region can make full use of the mature Si-based IGBT processes and cell structures with high carrier channel mobility and long electron-hole lifetime. Meanwhile the edge termination benefits from the high critical electric field of SiC and its breakdown voltage can easily reach the ideal value with excellent process windows. The ruggedness and reliability of the device can also be significantly improved because the avalanche occurs inside the silicon bulk and is far from the dielectric/semiconductor interface. The excellent characteristics of the edge termination are studied in detail by simulation. It is shown that the proposed edge structure has higher reliability in terms of the hot carrier effects and much less sensitivity to the interface charges in terms of breakdown degradation.

Mechanism analysis of IGBT turn-on process

Based on the internal structure of IGBT, the characteristics of gate voltage, collector current and collector-emitter voltage of IGBT during its turn-on process are studied in this paper. The relationship between gate voltage and gate capacitance is given, and the rising process of gate voltage is described in detail. According to the characteristics of IGBT turn-on current, a quadratic function is proposed to fit the collector current waveform. The influence of the main circuit stray inductance on collector-emitter voltage waveform is also analyzed. Finally, the IGBT dynamic switch characteristic test platform is built, and the measurement results verify the correctness of the analysis.

Limitation of switching-self-clamping-mode “SSCM” in high voltage IGBTs

In this paper, the self-clamping mechanism and the current filament behavior are investigated during the Switching-Self-Clamping-Mode “SSCM” of high voltage FS-IGBTs. By means of theoretical analysis and numerical device simulation, it is found that the current filament during the self-clamping tends to be stationary, which makes the safe operating area (SOA) of device limited by the local over-current instead of the over-voltage. And for the IGBT with the higher current gain αpnp, the self-clamping is caused by the remaining plasma that cannot be removed.

Novel Topology of DC Energy-Released Circuit For Saturated-Core Fault Current Limiter

The saturated-core fault current limiter (SCFCL) has been studied by several scholars in the past decades. However, these studies have mainly focused on the AC coils of the SCFCL, the DC excitation has seldom been mentioned. In this paper, the DC coil of SCFCL is studied as well as the influence of the novel structure of tightly-coupled SCFCL (TSCFCL) on the voltage of DC coil. A novel DC energy-released circuit is proposed, which overcomes the shortcoming of traditional single topology whose energy-released speed is limited by withstanding voltage of IGBT. In order to select a suitable structure of air gap for fault current limiter, the effects of different structures on the saturation of the core are studied. A novel simulation method is presented in this paper which can overcome the drawback of traditional finite element analysis cannot simulate the switching characteristics of IGBT under high frequency. Finally, a prototype is manufactured to verify the theory of this paper.

Partial discharge measurement and analysis in high voltage IGBT modules under DC voltage

Insulation performance of high voltage IGBT modules is one of the key attributes in power system applications. However, the existing standards of IGBT devices and research on the evaluation of insulation performance of high voltage IGBT modules are insufficient; for example, partial discharge resistance under DC voltage blocking condition is not considered. In this paper, a new test was proposed to allow the measurement of partial discharges in all the components of IGBT modules under DC voltage. The topology of the measuring circuit is arranged in the polarity discrimination way to exclude the interference, and the voltage and discharge current waveforms during the partial discharge process are measured by the wideband time domain measurement technique. According to the proposed test, the discharge phenomenon of the IGBT modules below the rating voltage were detected. A comprehensive waveform analysis on the voltage and discharge current was performed, and the influence of the applied voltage on the waveform parameters was obtained. The waveform parameters are influenced by the applied voltage and insulation structure, which enables the discrimination of the causes of the observed partial discharge in the IGBT module under DC voltage by the waveform analysis technique. Based on the waveform analysis technique, the types and causes of the observed partial discharges were discussed and inferred, and the correctness of the inference was further verified by observation. The proposed test and waveform analysis technique provide the possibility to evaluate and distinguish partial discharges in the high voltage IGBT module under DC voltage, which may be helpful to insulation performance evaluation and insulation defect diagnosis in high voltage IGBT module.