Wireless power transfer (WPT) technology makes it possible to supply power through an air‐gap, without the need for current‐carrying wires. One important technique of WPT technology is magnetic resonant coupling (MRC) WPT. Based on the advantages of MRC WPT, such as safety and high power transfer efficiency over a long transmit distance, there are many possible applications of MRC WPT. This study provides a comprehensive, state‐of‐the‐art review of the MRC WPT technology and wireless charging for electric vehicle (EV). A comparative overview of MRC WPT system design which includes a detailed description of the prototypes, schematics, compensation circuit topologies (impedance matching), and international charging standards. In addition, this study provides an overview of wireless EV charging including the static wireless EV charging and the dynamic wireless EV charging, which focuses on the coil design, power transfer efficiency, and current research achievement in the literature.
22 March 2018 in IEEE Transactions on Industrial Electronics
This paper describes a control algorithm for a battery energy storage system (BESS) to deliver a charge/discharge power output in response to changes in the grid frequency constrained by the National Grid Electricity Transmission (NGET)-the primary electricity transmission network operator in the U.K.-while managing the state of charge of the BESS to optimize the availability of the system. Furthermore, this paper investigates using the BESS in order to maximize triad avoidance benefit revenues while layering other services. Simulation using a 2 MW/1 MWh lithium-titanate BESS validated model is carried out to explore possible scenarios using the proposed algorithms. Finally, experimental results of the 2 MW/1 MWh Willenhall Energy Storage System verify the performance of the proposed algorithms.
Unmanned Aerial Vehicles (UAVs) technology has seen a significant boost in the past ten years and has been widely adopted in entertainment, rescue, intelligent transportation, no-touch delivery, environmental monitoring and other real world applications. However, the ranging limitation due to the shortage of battery energy capacity remains a major issue hindering further development of UAVs. Wireless power transfer (WPT) technology is a new technology of great potentials in improving the endurance of UAVs. The integration of WPT into UAV not only activates the recharging of UAVs batteries, but also enables UAVs to recharge other devices. Moreover, wireless charging technology allows the device to be fully enclosed and suitable for harsh weather conditions. This paper presents a comprehensive review in regard to the state-of-the-art of near-field WPT technologies for UAV charging, including technologies characteristics, design issues, as well as multiple case studies. A comparative analysis of existing technologies are also presented, associated with key future research discussions of WPT for UAVs.
Electrical modelling of rail tracks with multiple running trains is complex due to the difficulties in solving the power flow. The train positions, speed and acceleration are constantly varying resulting in a nonlinear system. In this work, a method is proposed for modelling DC electric railways to support power flow analysis of a simulated metro train service. The method exploits the MathWorks simulation tool Simscape, using it to model the mechanical and electrical characteristics of the rail track system. The model can be simulated to provide voltages at any position in the track and additionally, the voltages seen by any train. The model includes regenerative braking on trains, this is demonstrated to cause overvoltage in the feeding line if it is higher than the power demand of the other trains at that time. Braking resistors are used to protect the network from overvoltage by burning the excess energy. Through the implementation of Energy Storage Systems (ESSs), it will be possible to improve the energy efficiency and remove timetabling restrictions of electric railways by effectively controlling the rail track voltage. The paper proposes several methods to validate the model.