In this study, a lithium (Li)-ion battery equipped with an AC feature suitable for using in electric/hybrid vehicles is presented. The AC feature is implemented based on a proposed single-phase symmetric pulse-width modulation technique. Using the proposed Li-ion battery including both DC and AC features (DC–AC power source) in electric/hybrid vehicles has some advantages such as less electric power consumption compared with a normal Li-ion battery, no generated harmonics and the capability of choosing the AC voltage frequency. Simulated results obtained by performing in Proteus 6 environment validate the theoretical results presented in this study. An experimental prototype of the proposed DC–AC power source has been built. The experimental results not only verify the simulation and theoretical results but also show that 20% reduction in the electric power consumed by electric/hybrid vehicles is achieved using the proposed DC–AC power source.

In recent years there has been an increase in the number of unmanned aerial vehicle (UAV) applications intended for various missions in a variety of environments. The adoption of the more-electric aircraft has led to a greater emphasis on electrical power systems (EPS) for safe flight through an increased number of critical loads being sourced with electrical power. Despite extensive literature detailing the development of systems to detect UAV failures and enhance overall system reliability, few have focussed directly on the increasingly complex and dynamic EPS. This study outlines the development of a novel UAV EPS fault classification and diagnostic (FCD) system based on hidden Markov models (HMM) that will assist and improve EPS health management and control. The ability of the proposed FCD system to autonomously detect, classify and diagnose the severity of diverse EPS faults is validated with development of the system for NASA's advanced diagnostic and prognostic testbed (ADAPT), a representative UAV EPS system. EPS data from the ADAPT network was used to develop the FCD system and results described within this study show that a high classification and diagnostic accuracy can be achieved using the proposed system.

Nowadays, in several European Railway networks, the old DC supply systems are severely limited by line-voltage drops. In some sectors, it is not possible to increase traffic or to operate locomotives at their nominal ratings. To increase the capacity of a DC supply system, without additional substations, the authors propose a new three-wire supply system which restores the overhead line voltage with multilevel DC choppers operating as voltage boosters. Circuits using a third wire with a negative or a positive polarity are considered and compared. Case studies are presented for the French and Italian rail networks. Finally, experimental results performed on a test platform of the French railways, are presented in the case of a double 1.5 kV supply system.

This study presents a new concept for single-phase diode bridge rectifier circuits applied to automotive applications. The proposed circuit is able to enhance the output voltage to a much higher output level over a wide load range compared to the classical single-phase diode bridge rectifier without using complex control algorithms. This is achieved by embedding two capacitors and two switches to a new designed diode bridge converter topology. The embedded capacitors are charged and discharged simultaneously with the help of two switches. The embedment of the capacitors and switches will provide two functions: energy storage as known from traditional rectifier circuits and voltage oscillation with the supply inductance to reduce supply current distortion. The switches are on/off event triggered and do not require any complex control algorithms. The operation and the performance of the proposed rectifier are simulated using Matlab/Simulink software. Experimental results are obtained from a 1 kW prototype test circuit, which is used to evaluate the performance of the proposed circuit. Test results show a significant increase in the output voltage in addition to a reduced supply current distortion.

With the power quality problems of electric railways becoming more and more serious, static VAr compensators (SVCs) have been widely used for power quality management. SVCs can be installed in the low-voltage side of traction substations, the high-voltage side of traction substations or the electric railway power supply side of substations. Different installation positions result in different compensation effects. In this study, characteristics of harmonic and negative sequence currents in the low-voltage and high-voltage sides of traction substations are analysed theoretically. Four schemes with SVCs in different installation positions are proposed. Then based on the measured datum and waveforms, simulation of each scheme is implemented, respectively, using PSCAD/EMTDC software. By comparing the compensation effects of the four schemes, the best SVC installation scheme in the low-voltage side of the traction substation is recommended for the measured traction substation. With SVC, the electric railway will have a less negative effect on the power grid. This study can also be applied to other SVC applications with non-linear loads, such as arc furnaces, rolling mills or electrochemical devices.

A thruster fault tolerant control method based on quantum-behaved particle swarm optimisation (QPSO) is investigated for 7000 m JIAOLONG manned submarine vehicle (MSV) in this study. First, QPSO is selected for the fast convergence and global search capability. To show the efficiency of QPSO fault tolerant method, PSO is studied as a comparison research. Then, to further apply the proposed method, tracking control problem with thruster fault is taken into consideration. Finally, simulations illustrate the performance of the derived fault tolerant tracking control technique.