Investigating a MOSFET Driver (Buffer) Circuit Transition Ringings Using an Analytical Model

In this paper, a new analytical model introduced extracting from datasheet of a MOSFET and developed a MATLAB code for simulating a MOSFET driver circuit is proposed in the literature to observe the ringings of its output for capacitively loaded case. The output waveform is studied only for high-to-low transition. Gate drive resistance, wiring parasitics of the printed circuit board layout, and the characteristic properties of the MOSFET affect both the delay time of the MOSFET to become ON and performance of the driver circuit. Also, voltage stress of the MOSFET and therefore safe operating range for the circuit all depend on these effects. These effects are all considered in the design stage. The simulation results obtained from CST Design Studio software are compared with the results of experimental work. The analytical modeling results solved in the MATLAB are found congruent with the simulation results and experimental results as well. The simulation work showed that developed MATLAB code along with extracted models from datasheets has less convergence problems and also requires less simulation time

Channel current analysis of GaN HEMTs with source sense pin in DC/DC boost converters

The breakdown strength and electron mobility of gallium nitride (GaN) are almost ten and three times higher than those of the silicon devices. Wide band-gap devices have a higher thermal conductivity, higher switching frequency capability, lower on-state resistance and lower power dissipation. Detailed analytical models in the electrical network and channel current variations of these devices during switching intervals are still under investigation. The energy loss and heat dissipation on a power converter can be precisely estimated if the operational modes and the corresponding mathematical models of the device are accurately obtained. Depending on the instantaneous values of the channel current and voltage drops on the components computed from the model, the power dissipation and thermal response can be examined. Prediction of the switching losses of a GaN high electron mobility transistor (HEMT) with a source sense pin can be performed using the instantaneous variation of channel current. In this paper, a detailed analytical model including the stray inductances and parasitic capacitors is derived to obtain the channel current of GaN HEMTs with a source sense pin. The turn-on and turn-off transient energy losses during the switching of a single GaN HEMT device can be computed from the analytical model proposed in this paper using the channel current and drain-source voltage. Results of the derived analytical model, SPICE simulations and experimental work on the DC/DC boost converter are compared

Efficiency Calculation of Inverter for PV Applications Using MATLAB and SPICE

The purpose of this paper is to estimate the efficiency of the inverter circuits used for the Photovoltaic (PV) systems. The analysis of a power electronics converter with the SPICE during the steady-state operation takes a long time and the results may not be obtained accurately due to convergence problem in the solver. The MATLAB package program is widely preferred to analyze the power electronics converters if the switching losses are not taken into account and efficiency of the converter is not main purpose of the study. Here, In order to perform a detailed efficiency analysis of converter with SPICE program, the gate signals of IGBTs have been generated as a text file in MATLAB simulation of the same converter and that data has been transferred into the SPICE. The simulation results are verified with experimental results. The algorithm developed here is applicable to all converters that can be simulated in the MATLAB and the SPICE. Hence this approach is very useful to compare the efficiencies of the power electronic converters which are alternative to each other

Single-Phase Transformerless Photovoltaic Inverter With Suppressing Resonance in Improved H6

In low-power applications of photovoltaic (PV) systems, the transformerless grid-connected inverters have been preferred to increase the efficiency and reduce the cost, size, and power losses when they are compared to the ones with the transformer. A transformerless single-phase inverter topology with a single dc-link capacitor for the grid-connected PV systems is proposed in this paper. The proposed inverter has been simulated by using a cooperation process of the MATLAB and SPICE package programs and it has been implemented for experimental verification. The proposed inverter reduces the high-frequency common-mode leakage current caused by parasitic capacitances of PV panels, whereas it is controlled with the unipolar sinusoidal pulsewidth modulation. Also, the results show that the common-mode voltage remains constant. The efficiency of the proposed inverter has been compared to that of the most common topologies having the dc-link decoupling during the zero voltage states. This paper is accompanied by a video file demonstrating the power loss distribution in the inverter

Design and PSPICE analysis of a grid connected multilevel converter with reduced number of switches

In this paper, PSPICE analysis and design of grid connected multilevel converter will be presented. This converter has all the features of H-bridge structure, while it has six semiconductor switches and drivers to produce five-level output voltage. Reduction of IGBTs and drivers decreases the converter losses and system cost. The PSPICE analysis is used to predict the spikes on the collector emitter voltages and to design the snubber circuit. The converter is implemented in the three-phase Y-connected Statcom by using a digital control algorithm realized in floating point DSP TMS28335