Search

A fully integrated 0.18 [micro]m DC-DC buck converter using a low-swing 'stacked driver' configuration is reported in this paper. A high switching frequency of 660 MHz reduces filter components to fit on chip, but this suffers from high switching losses. These losses are reduced using: 1) low-swing drivers; 2) supply stacking; and 3) introducing a charge transfer path to deliver excess charge from the positive metal-oxide semiconductor drive chain to the load, thereby recycling the charge. The working prototype circuit converts 2.2 to 0.75-1.0 V at 40-55 mA. Design and simulation of an improved circuit is also included that further improves the efficiency by enhancing the charge recycling path, providing automated zero voltage switching (ZVS) operation, and synchronizing the half-swing gating signals. Index Terms--Charge recycling, integrated output filter, low-power stacked driver, subgigahertz switching, switch mode DC-DC converter.

A new gate-drive solution, cascade active voltage control (Cascade AVC), employs classic feedback-control methods with an inner loop controlling the insulated-gate bipolar-transistor (IGBT) gate voltage and an outer loop controlling the collector voltage, simultaneously. They make the switching performance less dependent on the IGBT itself. Feedback control of IGBTs in the active region does not necessarily slow the switching but introduces stability issues. A detailed stability analysis provides a sensible perspective to judge the system stability and justify the controller design, through considering major operating points and determining corresponding IGBT parameters. Experiments on high-power IGBTs including a 4500-V device show that Cascade AVC offers improved performance and is easier to design than the original AVC. Index Terms--Cascade active voltage control (Cascade AVC), controlled switching, high-power insulated-gate bipolar transistor (IGBT), series connection, stability.

A multiobjective genetic algorithm (MOGA) is used to compare submarine propulsion concepts and seek out tradeoffs in their design. Concepts include the novel integrated electric propulsion (IEP) concept and hybrid steam turbine and electric motor drive. System design and supervisory controllers are optimized under multiple operating conditions to give maximum propulsive efficiency. The advantages of each propulsive topology are compared, along with tradeoffs in their design. The hybrid steam turbine/electric motor drive is found to give superior propulsive efficiency compared with pure mechanical and pure electrical drive topologies. The optimal hybrid drive system design favors a large steam turbine and smaller electric motor, which is utilized during slow cruise speeds and top speed cruising only. Optimization of the supervisory controller simultaneously with the system design is found to give improvements in overall propulsive system efficiency. Index Terms--Hybrid drive, integrated electric propulsion (IEP), multiobjective genetic algorithm (MOGA), submarine propulsion, supervisory controller optimization.

This paper presents the application of compact insulated gate bipolar transistor and p-i-n diode models, including features such as local lifetime control and field-stop technology, to the full electrothermal system simulation of a hybrid electric vehicle converter using a lookup table of device losses. The vehicle converter is simulated with an urban driving cycle (the Federal Urban Driving Schedule), which is used to generate transient device temperature profiles. A methodology is also described to explore the converter reliability using the temperature profile, with rainflow cycle counting techniques from material fatigue analysis. The effects of ambient temperature, driving style, and converter design on converter reliability are also investigated. Index Terms--Compact modeling, electrothermal simulation, mission profile, power semiconductor devices, rainflow cycle counting, reliability, thermal cycling.

Although insulated-gate bipolar-transistor (IGBT) turn-on losses can be comparable to turn-off losses, IGBT turn-on has not been as thoroughly studied in the literature. In the present work IGBT turn on under resistive and inductive load conditions is studied in detail through experiments, finite element simulations, and circuit simulations using physics-based semiconductor models. Under resistive load conditions, it is critical to accurately model the conductivity-modulation phenomenon. Under clamped inductive load conditions at turn-on there is strong interaction between the IGBT and the freewheeling diode undergoing reverse recovery. Physics-based IGBT and diode models are used that have been proved accurate in the simulation of IGBT turn-off. Index Terms--Compact semiconductor device models, insulated-gate bipolar-transistor (IGBT) turn-on, interaction, physics-based semiconductor modeling.

This paper presents the development and implementation of a physics-based diode model which can simulate aspects of high-voltage diodes such as snappy recovery during punch-through and the modified carrier density profile due to local lifetime control. It uses a Fourier series solution for the ambipolar diffusion equation in the lightly doped base region. The model is compared with finite-element device simulations. A parameter extraction procedure for the diode with lifetime control is proposed in Part II. Index Terms--Lifetime control, physics-based model, p-i-n diode model, power semiconductor modeling, variable lifetime.

In this paper, a parameter extraction procedure for high-voltage diodes with local lifetime control is proposed. It is designed for use with the physics-based diode model described in Part I, which is capable of simulating diodes with local lifetime control. The parameter extraction procedure described requires a forward characteristic and a reverse recovery measurement. The parameter extraction procedure is illustrated using finite-element simulations. The physics-based model using the parameters extracted is then compared with experimental results. Index Terms--Lifetime control, physics-based model, p-i-n diode model, power semiconductor modeling, variable lifetime.

This paper concentrates on two critical aspects to improve the performance of maximum power point tracking (MPPT). One improvement is to accurately locate the position of the maximum power point (MPP) by using the centered differentiation. Another effort is to reduce the oscillation around the MPP in steady state by controlling active perturbations. This paper also adopts the method of steepest descent for MPPT, which shows faster dynamic response and smoother steady state than the method of hill climbing. Comprehensive experimental evaluations have successfully illustrated the effectiveness of the proposed algorithm. Index Terms--Control systems, digital control, maximum power point tracking (MPPT), photovoltaic power systems.

This paper presents a new technique for analyzing the conditions to which power semiconductor devices are subjected within practical inverters. A representative load cycle, which defines the inverter conditions, is used to estimate the switching conditions of the devices. Condition maps are generated, which allows the design and testing of the system to consider the more likely range of conditions. Estimates of temperature profiles can also be made to further improve the realism of such design. This promises to lead to the development of more realistic optimization procedures. Index Terms--Conditions, device testing, load cycles, optimization, power semiconductor devices.

Recently, a simulation method for power electronic devices has emerged, which has high accuracy and short run times based on a Fourier model of the device physics. This paper describes the use of the Fourier models for diodes and insulated gate bipolar transistors (IGBTs) and implementation in MATLAB and Simulink in a formal optimization strategy. In particular, this paper investigates coupled circuit, diode, and IGBT behavior. Conclusions are drawn concerning device loading and circuit design, particularly the role of stray inductance. Index Terms--Circuit modeling, diode, insulated gate bipolar transistor (IGBT), MATLAB, optimization, physics-based semiconductor device models, power semiconductor modeling, simulation, Simulink.

In photovoltaic power systems, both photovoltaic modules and switching-mode converters present nonlinear and time-variant characteristics, which result in a difficult control problem. This paper presents an in-depth analysis and modeling to discover the inherent features of a photovoltaic power system. The method of successive linearization simplifies the nonlinear problem back to the linear case. This paper also presents the use of Youla parameterization to design a stable control system for regulating the photovoltaic voltage. The experimental and simulation results demonstrate the effectiveness of the presented analysis, design, and implementation. Index Terms--Digital control, modeling, Nyquist stability, photovoltaic power systems, voltage control.

Feedback control of insulated gate bipolar transistors (IGBTs) in the active region can be used to regulate the device switching trajectory. This facilitates series connection of devices without the use of external snubber networks. Control must be achieved across the full active region of the IGBT and must balance a number of conflicting system goals including diode recovery. To date, the choice of control parameters has been a largely empirical process. This paper uses accurate device models and formalized optimization procedures to evaluate IGBT active voltage controllers. A detailed optimization for the control of IGBT turn-on is presented in this paper. Index Terms--Active voltage control (AVC), optimization, power semiconductor device modeling, series insulated gate bipolar transistors (IGBTs).

A practical and accurate parameter extraction method is presented for the Fourier-based-solution physics-based insulated gate bipolar transistor (IGBT) and power diode models. The goal is to obtain a model accurate enough to allow switching loss prediction under a variety of operating conditions. In the first step of the extraction procedure, only one simple clamped inductive load test is needed for the extraction of the six parameters required for the diode model and of the 12 and 15 parameters required for the nonpunch-through (NPT) and punch-through (PT) IGBT models, respectively. The second part of the extraction procedure is an automated formal optimization step that refines the parameter estimation. Validation with experimental results from various structures of IGBT demonstrates the accuracy of the proposed IGBT and diode models and the robustness of the parameter extraction method. Index Terms--Insulated gate bipolar transistor (IGBT) model, optimized parameter extraction, parameter extraction, power diode model, semiconductor modeling.

The operation of an insulated gate bipolar transistor (IGBT) in its active region is a well established technique for withstanding short circuits and also for dv/dt control. In this paper, we exploit the active behavior of the IGBT, applying a voltage feedback loop to the IGBT to control its switching. It is shown that adding a bias to the demand reference waveform shifts the IGBT into the active region and permits wide bandwidth operation over most of the switching transient. The operation of the IGBT is reported in detail, making reference to a selection of experimental waveforms for 400-A, 1700-V capsule IGBTs. The implementation required for control of such large IGBT modules and capsule devices for high power applications is described and discussed. It is concluded that the active voltage control method allows the operation of high power IGBT circuits to be closely defined. Index Terms--Active voltage control method, dv/dt control, insulated gate bipolar transistor (IGBT).

The switching characteristics (turn-on and turn-off) and forward conduction drop of trench-gate punch-through insulated gate bipolar transistors (IGBTs) are examined over a temperature range of from -50[degrees]C to 125[degrees]C. An analytical description of the forward conduction voltage drop is presented based on temperature dependencies of the appropriate physical parameters and mechanisms. A physics-based PSpice model, incorporating much of the device behavior, is also described. Results from the model are compared to experimental waveforms. Index Terms--Electrothermal semiconductor models, insulated gate bipolar transistor (IGBT), physics-based power semiconductor models, power semiconductor modeling, punch-through (PT) IGBT.

The problems faced in generating analytical models for the insulated gate bipolar transistor (IGBT) and power diode are devising correct equations and determining realistic boundary conditions, especially for two-dimensional (2-D) features, while ensuring convergence of the models. These issues are addressed in this paper in relation to the temperature dependent modeling of NPT IGBTs and diodes. Simulation and experimental results are presented and compared to validate the modeling approach. Index Terms--IGBT, physics-based semiconductor device models, power diode, quasi-2-D semiconductor device models.

The high-voltage field-stop (FS) insulated gate bipolar transistor (IGBT) is a promising power device for high-power applications thanks to the robust characteristics offered by the FS technology, which combines the inherent advantages offered by punch-through and nonpunch-through structures while overcoming the drawbacks of each structure. in this paper, an electrothermal physics-based model for the FS IGBT is developed. The model contains a detailed description of the FS layer and it is validated using experimental results for a commercial 1200-V/60-A FS IGBT over the entire temperature range specified in the data sheets. The validated model is then used to simulate a 6.5-kV FS IGBT. The simulation results are compared with experimental results published in the literature and good agreement is obtained. Index Terms--Field-stop insulated gate bipolar transistor (FS IGBT), high voltage IGBT, physics-based power semiconductor models, power semiconductors modeling.

This paper presents the reasons that make series operation of insulated gate bipolar transistors (IGBT's) attractive and challenging and reviews the methods that may be used. Then, a new approach, which uses the IGBT's gate-controlled active regime in place of large voltage-sharing snubbers, is proposed. Analytical and simulation techniques are used to study the performance and conditions for stability given. It is concluded that when making each IGBT voltage follow a reference input, with closed-loop voltage control, the IGBT's are able to share the transient turn-off voltage without turn-off snubbers. This technique may lead to more compact and efficient high-voltage-power modules. Index Terms - Active voltage control, gate drives, high-voltage switching, IGBT, series connection.

The redistribution of anode current during turnoff transient, which limits peak commutable current of a GTO thyristor, is analyzed by comparing total turnoff current density with the static and dynamic characteristics of individual segments. The initiation of filamentation and subsequent device failure influences current density distribution behavior during current fall and the early tail period.

This study presents a physics-based compact model of the integrated gate-commutated thyristor (IGCT) with multiple effects for the high-power application. The proposed model has both acceptable accuracy and computation time requirement, which is suitable for system level circuit simulation and IGCT's whole wafer modelling work. First, the development of IGCT model is discussed and the one-dimensional phenomenon of IGCT is analysed in this study. Second, a physics-based compact model of IGCT is proposed. The proposed model of IGCT includes multiple physical effects that are crucial to IGCTs working in high-power applications. These physical effects include the impact ionisation effect, moving the boundary of the depletion region during the punch-through and the local lifetime region. The Fourier series solution is applied to the ambipolar diffusion equation in the base region. Third, the proposed model is implemented in Simulink and compared with the model in Silvaco Atlas, a finiteelement tool. Finally, the proposed compact model of IGCT is validated by experiments. [ABSTRACT FROM AUTHOR]

Over three decades of development effort has brought insulated gate bipolar transistor (IGBT) technology to a high-level of maturity. IGBT converters have been widely used in industry. However, the high-speed switching transient of the IGBT-freewheel diode chopper cell causes high-level electromagnetic interference (EMI). Electromagnetic compatibility requirements are normally taken into account by utilising costly EMI filters or shielding on the load and supply side. The risk of this traditional method is to incur a delay in commercialising the converters since identification of the failure causes, modifications, and successfully re-testing are required. A promising alternative is to constrain the EMI at source by introducing active voltage control technique and shaping the IGBT switching transient into a sophisticated 'S'-shape. Previously, IGBT switching waveforms have been successfully shaped into an advanced Gaussian 'S'-shape with the EMI greatly reduced. In this study, the authors further investigated the trade-off between EMI generation and switching losses in such an S-shaping method. The investigation was carried out in an accurate physical IGBT/diode model that is able to accurately simulate the device switching transient. From the results, it can be seen that by using the Gaussian S-shaping method the trade-off between EMI and switching losses could be much improved. [ABSTRACT FROM AUTHOR]