More and more electric vehicles and charging stations are penetrating into the power system today which introduce new challenges. As a result, the concept of vehicle to vehicle charging (V2V) is gaining interest. Therefore, it is important to understand the concept of V2V charging. In this paper, some of the recent developments in the area of vehicle to vehicle (V2V) charging are explored.
Growing deployments of ultra fast charging stations (XFCS) are putting a stress on the existing line-frequency transformer (LFT)-based medium voltage (MV) grid due to the high charging demands of exponentially growing electric vehicles (EV). The conventional LFT occupies a large space in the XFCS installation which introduces challenges in facilitating the XFCS infrastructure. As a result, solid-state transformer (SST)-based XFCS are being developed which can be directly connected to the MV grid and several advantages over LFT-based systems such as compactness, intelligence and availability of the DC link to connect renewable energy sources and storage system can be realized. As such, a detailed analysis of current developments in SST-based XFCS is presented and compared with one another in this paper. The challenges associated with the configurations are examined and direction for future research is identified.
This paper presents a torque control to drive the motors of a quadcopter UAV in order to track the desired trajectories designed for a specific mission. As the quadcopter is an underactuated, nonlinear, strongly coupled system, it requires an effective torque control technique to overcome its complex behavior and deal with internal/external disturbances and system parameter uncertainties. The proposed torque control strategy takes advantage of the simplicity of the active disturbance rejection control (ADRC) as well as the robustness of the fractional control. This fractional ADRC consists mainly of a fractional Extended State Observer (ESO) and a fractional state error feedback (SEF). The fractional ESO is adopted to estimate the total disturbances acting on the system as well as unmodeled system dynamics. The fractional SEF is used to actively reject the disturbances and then steer the quadcopter output to their desired values and improve the transient attitude control performance. The proposed torque controller has been used to drive the motors of the quadcopter system to control the attitude subsystem. The simulation results demonstrate the superiority of the fractional ADRC approach compared to the nonfractional version and show its effectiveness in controlling complex UAV systems subject to various disturbances.
Accurate junction temperature estimation is essential in power module applications to ensure optimal performance, reliability, and lifespan. This paper investigates the impact of threshold voltage $(V_{th})$ mismatch on in-situ junction temperature estimation for SiC MOSFET multichip power module based on the turn-ON delay time $(t_{d,on})$ . The $t_{d, \text { on }}$ of power modules and its temperature dependence are related to the $V_{th}$ of each chip within the power module. Simulations on the $V_{th}$ mismatch of paralleled MOSFETs demonstrate that selecting a larger reference triggering voltage of $V_{s_{-}ref}$ enables the extraction of the mean junction temperature based on the $t_{d,on}$ of the power module. Moreover, the $V_{th}$ mismatch has almost no effect on the accuracy of the mean junction temperature estimation. Finally, calibration experiments are performed on a commercial half-bridge SiC MOSFET power module with $t_{d,on}$ extraction circuit. Experimental results show that the $t_{d,on}$ of SiC MOSFET power module has a linear temperature coefficient of $150\text{ps}/^{\circ}\mathrm{C}$ at the turn-ON resistance of $15\Omega$ and is independent of load current.
Electrolyzers are widely used in Renewable energy hydrogen production, and the performance of electrolyzers is directly related to DC-DC converters. To realize the highefficiency operation of the electrolyzer, new challenges, such as a high step-down ratio and low output current ripple, are put forward for the DC-DC converter. This paper proposes a novel type of DC-DC converter for hydrogen production. The topology is simple and has the advantages of higher step-down gain, zerovoltage switching without additional devices, and low switching stress. In addition, the scheme can achieve ultra-low output current ripple without active devices. Finally, this paper connects the electrolyzer hydrogen production load in the simulation to verify the scheme's effectiveness.
