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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]

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]

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]

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. [ABSTRACT FROM AUTHOR]

This paper presents a practical destruction-free parameter-extraction methodology for a new physics-based circuit simulator buffer-layer integrated gate-commutated thyristor (IGCT) model. Most key parameters needed for this model can be extracted by one simple clamped inductive-load switching experiment. To validate this extraction method, a clamped inductive-load switching experiment was performed, and corresponding simulations were carried out by employing the IGCT model with parameters extracted through the presented methodology. Good agreement has been obtained between the experimental data and simulation results. [ABSTRACT FROM AUTHOR]