The Influence of a 3D Model of a Radio Electronic Component on Thermal Simulation

Very often, when designing and developing radio electronic devices, engineers are regularly faced with the need to solve various kinds of problems to ensure the operation of a product under the required mechanical loads or thermal conditions during operation. One of the main issues that arise when conducting thermal modeling of radio electronics is the correct assessment of the results. There are a number of electronic components that need to be cooled, mainly through a printed circuit board: power supply transistors, power diodes, microcircuits, etc. For such elements, 90% (or more) of the heat flux from the component is diverted through the printed circuit board, and then to the radiator. Therefore, when carrying out the simulation, it is necessary to have previously obtained reliable temperature results on the power elements. The use of a detailed 3D model for modeling is most often unjustified and can introduce certain errors in the calculations. This article compares different 3D transistor models and the effect of detailing on the modeling process in CAD SolidWorks.

Analysis of a Series‑Parallel Resonant Converter for DC Microgrid Applications

An input-series output-parallel soft switching resonant circuit with balance input voltage and primary-side current is studied and implemented for direct current (DC) microgrid system applications. Two resonant circuits are connected with input-series and output-parallel structure to have the advantages of low voltage stresses on active devices and low current stresses on power diodes. A balance capacitor is adopted on high voltage side to balance two input capacitor voltages. The LLC (inductor–inductor–capacitor) resonant circuit cells are employed in the converter to have soft switching operation for power semiconductors. The magnetic coupling component is adopted on the primary-side to automatically realize current balance of the two resonant circuits. In the end, a laboratory hardware circuit is built and tested. Experiments demonstrate and prove the validity of the resonant converter.

Full Digital Control of an All-Si On-Board Charger Operating in Discontinuous Conduction Mode

This paper deals with the design, tuning and implementation of a digital controller for an all-Si electric vehicle (EV) on-board battery charger operated in discontinuous conduction mode (DCM). This charger consists of two cascaded conversion stages: a front-end power factor corrector (PFC) with two interleaved legs and an isolated phase-shifted full bridge DC/DC converter. Both stages operate in DCM over the complete battery charging power range, allowing lower inductance values for both the PFC and the DC/DC filtering elements. Moreover, DCM operation ensures a large reduction of the reverse-recovery losses in the power diodes, enabling the adoption of relatively cheap Si devices. The main goal of the work is to address the well-known DCM control challenges, leveraging a novel control strategy for both converter stages. This control scheme counteracts the DCM system non-linearities with a proper feed-forward contribution and an open-loop gain adjustment, ensuring consistent dynamical performance over the complete operating range. The designed controllers are tuned analytically, taking into account the delay components related to the digital implementation. Finally, the proposed control strategy is implemented on a single general purpose microcontroller unit (MCU) and its performance is experimentally validated on a 3.3 kW battery charger prototype.