Development of a 50 kW wireless power transfer system

A high-power modular wireless power transfer system has been developed intended for use in larger vehicles. This paper presents the design methodology and evolution of the system, including test results. The system utilises SiC switching devices and an 85 kHz operating frequency. 50 kW of wireless power transfer has been achieved over a 200 mm gap at 89% efficiency, showing good promise for the system

An effective islanding detection method for photovoltaic grid connected inverter / Ku Nurul Edhura Ku Ahamad

Presently, available international standard related to anti-islanding requirements on medium and low grid connected system required that voltage utility distribution network should be automatically disconnected from the distribution grid when the circuit breaker supplying the feeder connected to the distribution generation trips. Islanding is undesired because it may endanger maintenance service workers and damage load equipment through unsynchronized re-closure. In principle, the main idea of islanding is monitoring the changes in the output parameter of the inverters or other system parameters in indicating islanding. This thesis presented a low cost and effective passive anti-islanding detection method for single-phase photovoltaic grid-connected inverters. An analog circuit for over/under voltage protection is developed to ensure fast detection and no delay to system. An under- /over frequency circuit is also developed, for accurate and fast frequency detection with minimal external components. A new algorithm is developed in a low cost PIC18F4550. An improved disconnection time in the proposed method compared with that in the previously developed method is an attractive solution for single phase grid connected inverters. The low cost, effective and minimal external component count are the advantages. A prototype is developed and tested to demonstrate the performance and feasibility of the proposed method. The test was conducted on different combination of resistive, capacitive and inductive loads. The experiment results verified that the proposed anti-islanding detection method is able to detect islanding operation effectively under various load types, inverter output powers and quality factors

Design, build and retrofit of a 20 kW automotive wireless charging system using CCS interface

This paper presents a case study of the full development process from modelling and design to build, vehicle integration and testing of a 20 kW rated wireless charging system. The combined charging system (CCS) DC charging interface on the vehicle was used for vehicle charging and communication. The work motivation along with details of the system design, construction and vehicle integration are included in this paper. The main learning points are discussed and test results showing the final system in operation are presented

Kinetics of diesel degradation by an acrylamide-degrading bacterium

In this work, we characterized a novel acrylamide-degrading bacterium with the ability to degrade diesel. Tentatively, the isolate was identified as Burkholderia sp. strain DRY27 and was shown to have increased growth rate on media supplemented with 0–3 % (v/v) diesel. We showed that sodium nitrate is the best nitrogen source for the bacterium growth on diesel. The optimal temperature and optimal pH supporting growth on diesel were between 10 and 40 °C and pH 7.5–8.5, respectively. Growth kinetics modeling showed that the Haldane model gave a correlation coefficient value of 0.99 and was better than other kinetic models such as Luong or Monod. Using the Haldane model, the maximum growth rate (µ max) was 0.305 h−1, while the saturation constant or half-velocity constant K s and inhibition constant K i, were 1.171 % (v/v) or 9.95 g/L and 3.215 % (v/v) or 27.32 g/L diesel, respectively. Microbial adhesion to hydrocarbon assay showed that after extraction, 65 % of the bacterium was found in the hexadecane phase indicating that the bacterium was hydrophobic. We showed that diesel components were completely removed based on the reduction in the hydrocarbon peaks monitored by solid-phase microextraction gas chromatography analysis