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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.

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 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.

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 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.