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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.

The Fourier-series-based insulated-gate bipolar transistor (IGBT) model has been very effective in simulating its switching behaviors and meanwhile, reflecting carrier dynamics. However, in turn-on process, such a model has difficulty in distinguishing the boundary between undepleted area and depletion layer of the drift region due to Gibbs phenomenon and therefore, cannot accurately describe the carrier behavior of carrier storage region (CSR). In this study, the Fourier-series-based model is modified to determine the more precise depletion layer edge for turn on. This is achieved by utilizing the actual characteristics of the carrier concentration gradient at the edge of CSR in turn-on process. Such a modified model is implemented in MATLAB/Simulink and it can better reflect the depletion layer and simulate the distribution of both the carrier concentration and electric field during turn-on process. It corrects the unreasonable voltage tail caused by the error of drift region voltage calculation in previous models. The results of the proposed model under both the resistive load and inductive load are in good agreement with TCAD. Such a modified model can more accurately simulate both carrier dynamics and switching behaviors in the turn-on process. [ABSTRACT FROM AUTHOR]

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]

The series connection of IGBTs is essential for high-voltage applications where fast switching performances need to be maintained. However, unbalanced voltage sharing is a major resistance to the converter application of this structure. There are a number of causes leading to voltage unbalance, such as different signal delays, parasitic parameters, tail currents, and so on. A temporary clamp scheme performed by active voltage control (AVC) has been proven to be effective in solving the unbalanced voltage-sharing issue. However, the basic physics has not been investigated. In this paper, the physical principle of voltage unbalance within IGBTs series operation is discussed. The carrier storage region differences are concluded to be the intrinsic cause of unbalanced voltage sharing. By using an accurate Fourier-series-based IGBT simulation model with appropriate assumptions, a physical explanation for temporary clamp is provided in detail. At the end of the tail current period when the excess carrier concentration becomes close to the intrinsic doping density, the temporary clamp is able to achieve satisfactory equal voltage sharing. [ABSTRACT FROM PUBLISHER]

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]

The main idea of active voltage control (AVC) is to employ classic feedback-control methods forcing the IGBT collector voltage transient to follow a predefined trajectory. This feedback control of IGBTs has great advantages in guaranteeing that IGBTs remain in safe operating area (SOA), restricting EMI, mitigating the voltage/current stress, minimizing/predicting their power losses, and balancing voltages of IGBTs in series. Inevitably, however, AVC introduces stability issues. Based on the assumption that accurate IGBT small-signal model parameters are available, an analogue proportional-derivative and multiloop feedback control was proposed to achieve stable performance in previous work. Due to nonlinearities and uncertainties in IGBT parameters, previous stability analysis methods have important limitations. This work uses Kharitonov's theorem during the IGBT controlled turn-off to assess the system's stability and guide the AVC design to account for model uncertainties and varying parameters. We conducted experiments to investigate the system's robust stability due to these uncertainties in the IGBT parameters, which confirm the validity of the proposed theoretical analysis. With the use of wide bandwidth op-amps, it is shown that the feedback design may be simplified. [ABSTRACT FROM PUBLISHER]

Insulated-gate bipolar transistor (IGBT) terminal capacitances play an important role in IGBT switching transients. The terminal capacitance modelling is a difficult task because of their operating-point-dependent characteristics. In particular, the input capacitance needs careful treatment if accurate modelling is to be performed. Previously, for the planar gate IGBT, the Miller capacitance's voltage dependency is modelled by considering the depletion region growth pattern. For modern trench gate designs, however, there is no similar dynamic model available. Also, its current dependency needs to be accounted for. This study presents an improved IGBT physics-based model with input capacitance correction. By comparison of experimental and simulation results, the proposed model works well for different types of IGBTs (including the state-of-art trench-gate field-stop type) over a wide range of operating conditions and is convenient to implement. [ABSTRACT FROM AUTHOR]

High-performance power switching devices [insulated-gate bipolar transistors (IGBTs)] realize high-performance power converters. Unfortunately, with a high switching speed of the IGBT-freewheel diode chopper cell, the circuit becomes intrinsic sources of high-level electromagnetic interference (EMI). Therefore, costly EMI filters or shielding is normally demanded on the load and supply sides. An S-shaped voltage transient with a high-order time derivative eliminates the discontinuity in the switching transient and can suppress high-frequency spectrum of EMI emissions. More importantly, it provides an improved tradeoff between EMI generation and switching time, therefore switching losses. This promising tradeoff can be explored further for better high-frequency EMI suppression by using the infinitely differentiable characteristics of Gaussian S-shaped transients. However, current gate drive schemes cannot achieve the S shaping. In this paper, active voltage control is applied and improved successfully to define IGBT switching dynamics with a smoothed Gaussian waveform. [ABSTRACT FROM PUBLISHER]

Silicon carbide (SiC) bipolar junction transistors (BJTs) require a continuous base current in the on-state. This base current is usually made constant and is corresponding to the maximum collector current and maximum junction temperature that is foreseen in a certain application. In this paper, a discretized proportional base driver is proposed which will reduce, for the right application, the steady-state power consumption of the base driver. The operation of the proposed base driver has been verified experimentally, driving a 1200-V/40-A SiC BJT in a dc-dc boost converter. In order to determine the potential reduction of the power consumption of the base driver, a case with a dc-dc converter in an ideal electric vehicle driving the new European drive cycle has been investigated. It is found that the steady-state power consumption of the base driver can be reduced by approximately 60%. The total reduction of the driver consumption is 3459 J during the drive cycle, which is slightly more than the total on-state losses for the SiC BJTs used in the converter. [ABSTRACT FROM AUTHOR]

Large digital chips use a significant amount of energy to broadcast a low-skew, multigigahertz clock to millions of latches located throughout the chip. Every clock cycle, the large aggregate capacitance of the clock network is charged from the supply and then discharged to ground. Instead of wasting this stored energy, it is possible to recycle the energy by controlling its delivery to another part of the chip using an on-chip dc–dc converter. The clock driver and switching converter circuits share many compatible characteristics that allow them to be merged into a single design and fully integrated on-chip. Our buck converter prototype, manufactured in 90-nm CMOS, provides a proof-of-concept that clock network energy can be recycled to other parts of the chip, thus lowering overall energy consumption. It also confirms that monolithic multigigahertz switching converters utilizing zero-voltage switching can be implemented in deep-submicrometer CMOS. With multigigahertz operation, fully integrated inductors and capacitors use a small amount of chip area with low losses. Combining the clock driver with the power converter can share the large MOSFET drivers necessary as well as being energy and space efficient. We present an analysis of the losses which we confirm by experimentally comparing the merged circuit with a conventional clock driver. [ABSTRACT FROM AUTHOR]

With series insulated-gate bipolar transistor (IGBT) operation, well-matched gate drives will not ensure balanced dynamic voltage sharing between the switching devices. Rather, it is IGBT parasitic capacitances, mainly gate-to-collector capacitance Cgc, that dominate transient voltage sharing. As Cgc is collector voltage dependant and is significantly larger during the initial turn-off transition, it dominates IGBT dynamic voltage sharing. This paper presents an active control technique for series-connected IGBTs that allows their dynamic voltage transition dVce/dt to adaptively vary. Both switch ON and OFF transitions are controlled to follow a predefined dVce/dt. Switching losses associated with this technique are minimized by the adaptive dv /dt control technique incorporated into the design. A detailed description of the control circuits is presented in this paper. Experimental results with up to three series devices in a single-ended dc chopper circuit, operating at various low voltage and current levels, are used to illustrate the performance of the proposed technique. [ABSTRACT FROM AUTHOR]

An existing physics-based insulated gate bipolar transistor (IGBT) model, which has been proven accurate for both inductive turn-off and inductive turn-on simulations, is modified to account for planar-gate IGBT 2-D effects at the MOS end of the drift region. The modification is based on a steady-state solution of carrier distribution in the JFET region of the IGBT. The accuracy of this solution is verified through a set of finite element simulations. The improved accuracy of the modified model in terms of on-state forward drop and voltage tail at turn-on is verified through comparison with experimental results. [ABSTRACT FROM PUBLISHER]

In this paper, a new thermal model based on the Fourier series solution of heat conduction equation has been introduced in detail. 1-D and 2-D Fourier series thermal models have been programmed in MATLAB/Simulink. Compared with the traditional finite-difference thermal model and equivalent RC thermal network, the new thermal model can provide high simulation speed with high accuracy, which has been proved to be more favorable in dynamic thermal characterization on power semiconductor switches. The complete electrothermal simulation models of insulated gate bipolar transistor (IGBT) and power diodes under inductive load switching condition have been successfully implemented in MATLAB/Simulink. The experimental results on IGBT and power diodes with clamped inductive load switching tests have verified the new electrothermal simulation model. The advantage of Fourier series thermal model over widely used equivalent RC thermal network in dynamic thermal characterization has also been validated by the measured junction temperature. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]