This study aims to characterize the switching transients and power losses of silicon (Si) power metal–oxide–semiconductor field-effect transistor (MOSFET) in an SOT-227 package (hereinafter named “power MOSFET package”) and Si power MOSFET-based three-phase MOSFET inverter during load cycles through numerical modeling and experimental validation. The three-phase inverter comprises six power MOSFET packages as switches for brushless direct current motor drive. First of all, three-dimensional electromagnetic analyses are performed to extract the parasitic parameters of these two power devices. Subsequently, the device model and the previously derived package model of the power MOSFET are combined together in circuit simulation of a double pulse test (DPT). The calculated waveform profiles and switching times are compared with those obtained from the DPT experiment. Likewise, an effective compact circuit simulation model of the three-phase six-switch inverter, considering the parasitic effects, is developed for the switching loss estimation in the first switching interval of the six-step switching sequence. At last, parametric study is performed to explore, respectively, the influences of some crucial factors on the parasitic inductances and switching transients of the power MOSFET package and the switching losses of the three-phase inverter.

The purpose of this paper is to study the flow field of the combustion chamber in a simulated rotary engine by using a computational approach. A dynamic mesh technique is employed to overcome the moving and shape varying computational domain inside the combustion chambers as the rotor is spinning. The key parameters include spark plug timing, leading side spark plug location and intake port location, which are used to investigate their influences on flow field and combustion performance of a rotary engine. It was discovered, with a dual spark plug configuration, that better flame propagation could be obtained through the change of ignition timing. In addition, to change the leading side spark plug location, it was also found that combustion efficiency is improved by shortening the distance from the top dead center (TDC) center line, which is consistent with available experimental results. This research also discovered that the intake port should be properly located in order to prevent pressure loss in the combustion chamber during the compression stroke.

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Temperature resulting from the joule heating power and the turn-on and turn-off dissipation of high-power, high-frequency applications is the root cause of their thermal instability, electrical performance degradation, and even thermal-fatigue failure. Thus, the study presents thermal and electrical characterizations of the power MOSFET module packaged in SOT-227 under natural convection and forced convection through three-dimensional (3D) thermal-electric (TE) coupled field analysis. In addition, the influences of some key parameters like electric loads, ambient conditions, thermal management considerations (heat sink, heat spreader) and operation conditions (duty cycle and switching frequency) on the power loss and thermal performance of the power module are addressed. The study starts from a suitable estimation of the power losses, where the conduction losses are calculated using the temperature- and gate-voltage-dependent on-state resistance and drain current through the device, and the switching losses are predicted based on the ideal switching waveforms of the power MOSFETs applied. The effectiveness of the theoretical predictions in terms of device’s power losses and temperatures is demonstrated through comparison with the results of circuit simulation and thermal experiment.