We propose a device for monitoring the number of people who are physically present inside indoor environments. The device performs local processing of infrared array sensor data detecting people’s direction, which allows monitoring users’ occupancy in any space of the building and also respects people privacy. The device implements a novel real-time pattern recognition algorithm for processing data sensed by a low-cost infrared (IR) array sensor. The computed information is transferred through a Z-Wave network. On-field evaluation of the algorithm has been conducted by placing the device on top of doorways in offices and laboratory rooms. To evaluate the performance of the algorithm in varying ambient temperatures, two groups of stress tests have been designed and performed. These tests established the detection limits linked to the difference between the average ambient temperature and perturbation. For an in-depth analysis of the accuracy of the algorithm, synthetic data have been generated considering temperature ranges typical of a residential environment, different human walking speeds (normal, brisk, running), and distance between the person and the sensor (1.5 m, 5 m, 7.5 m). The algorithm performed with high accuracy for routine human passage detection through a doorway, considering indoor ambient conditions of 21–30 °C.

Wide Band Gap (WBG) semiconductor technologies such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are considered as the future of power electronic devices. Especially, in hard-switching applications where switching power losses are important, GaN devices are more attractive because of their very low gate charge amount. On the other hand, universal dc-dc power converters in Electric Vehicles (EVs) are coming into attention to be replaced with two power electronic modules: dc-dc battery charger and dc-dc traction drive. Unfortunately, current lateral GaN devices are not applicable in high power dc-dc traction drive, neither in universal dc-dc converters because of their limited current rating. As a solution, a two-phase dc-dc converter is proposed in this paper in which one phase is SiC-based MOSFET and the other one is GaN-based transistor. To reach the maximum utilization of the GaN device, the output power will be shared through the two phases, based on the current rating of the GaN device. First, the power stage design and the average model of the converter are presented. Then, power losses and efficiency of the converter is investigated in comparison with an all-SiC converter through spice-based simulations. The simulation results highlight the higher efficiency of the proposed converter.

Wide Band Gap (WBG) semiconductor technologies such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are being replaced with Silicon (Si) MOSFETs and IGBTs in power switching converters. In hard-switching applications, GaN is more attractive because of its lower switching power losses. The DC-DC power module of the motor drive in Plug-In Electric Vehicles (PEVs) has a power rating range of 30-150 kW while the power rating of GaN is not that much high. A two-phase SiC-GaN-based converter can satisfy the demanded power, achieving the advantage of WBG technology, and avoid the complexity of multi-phase converter with high number of phases. Obtaining the maximum efficiency, the power sharing is not symmetrical. Therefore, a cascade controller is considered in this paper to control fully directional universal converter: drive/plug-in, boost/buck mode. The simulation results prove the satisfactory performance of the controller in all modes of operation.

DC-DC converters are being used for power management and battery charging in electric vehicles (EVs). To further the role of EVs in the market, more efficient power electronic converters are needed. Wide band gap (WBG) devices such as silicon carbide (SiC) provide higher frequency and lower power loss, however, their high di/dt and dv/dt transients result in higher electromagnetic interference (EMI). On the other hand, some gate driver parameters such as gate resistor ( ${\mathrm{R}}_{\mathrm{G}}$ ) have a contradictory effect on efficiency ( $\mathsf{\eta }$ ) and EMI. The idea of this paper is to investigate the values of these parameters using a multi-objective optimization method to optimize $\mathsf{\eta }$ and EMI at the same time. To this aim, first, the effect of high and low side ${\mathrm{R}}_{\mathrm{G}}$ on $\mathsf{\eta }$ and EMI in the half-bridge configuration is studied. Then, the objective functions of the optimization problem are obtained using a numerical regression method on the basis of the experimental tests. Then, the values of the gate resistors are obtained by solving the multi-objective optimization problem. Finally, $\mathsf{\eta }$ and EMI of the converter in the optimum gate resistor design are compared to those in the conventional design to validate the effectiveness of the proposed design approach.

A new universal full-directional SiC-GaN-based two-phase DC-DC converter has been recently introduced. It is supposed to replace with DC-DC battery charger and DC-DC traction drive converters in Plug-In Electric Vehicles. The SiC-GaN-based converter is designed to have the advantage of low switching power loss of GaN in hard-switching application and also avoid a high number of paralleled phases for high power multi-phase DC-DC converter applications. Especially in this paper, a dead-time analysis is done for the state-of-the-art high power GaN and SiC components of the proposed converter. To this aim, a new Spice-based simulation method is presented to obtain precise dead-time power loss calculations. Furthermore, the effect of negative OFF gate-source voltage is investigated.