Investigation of Electromagnetic Force in 3P5W Busbar System under Peak Short-circuit Current

Electromagnetic forces on three-phase five-wire (3P5W) busbar system is investigated under three-phase short-circuits current. The conductor busbar placed in compact galvanized steel enclosure is in the rectangular shape. Transient analysis from Opera-2D is carried out to develop the model of three-phase short-circuits current in the system. The result of the simulation is compared with the calculation result, which is obtained by applying the theories of Biot Savart's law and Laplace equation. Under this analytical approach, the moment of peak short-circuit current is taken into account. The effect upon geometrical arrangement of the conductor and the present of the steel enclosure are considered by the theory of image. The result depict that the electromagnetic force due to the transient short-circuit from simulation is agreed with the calculation

A comprehensive review of electric vehicle charging stations with solar photovoltaic system considering market, technical requirements, network implications, and future challenges

Electric cars (EVs) are getting more and more popular across the globe. While comparing traditional utility grid-based EV charging, photovoltaic (PV) powered EV charging may significantly lessen carbon footprints. However, there are not enough charging stations, which limits the global adoption of EVs. More public places are adding EV charging stations as EV use increases. However, using the current utility grid, which is powered by the fossil fuel basing generating system, to charge EVs has an impact on the distribution system and could not be ecologically beneficial. The current electric vehicle (EV) market, technical requirements including recent studies on various topologies of electric vehicle/photovoltaic systems, charging infrastructure as well as control strategies for Power management of electric vehicle/photovoltaic system., and grid implications including electric vehicle and Plug-in hybrid electric vehicles charging systems, are all examined in depth in this paper. The report gives overview of present EV situation as well as a thorough analysis of significant global EV charging and grid connectivity standards. Finally, the challenges and suggestions for future expansion of the infrastructure of EV charging, grid integration, are evaluated and summarized. It has been determined that PV-grid charging has the ability to create a profit. However, due to the limited capacity of the PV as well as the batteries, the Power system may not be cost effective. Furthermore, since PV is intermittent, it is probable that it will not be able to generate enough electricity to meet consumer demand

Examination on the Denoising Methods for Electrical and Acoustic Emission Partial Discharge Signals in Oil

Partial discharge (PD) measurements either through electrical or acoustic emission approaches can be subjected to noises that arise from different sources. In this study, the examination on the denoising methods for electrical and acoustic emission PD signal is carried out. The PD was produced through needle-plane electrodes configuration. Once the voltage reached to 30 kV, the electrical and acoustic emission PD signals were recorded and additive white Gaussian noise (AWGN) was introduced. These signals were then denoised using moving average (MA), finite impulse response (FIR) low/high-pass filters, and discrete wavelet transform (DWT) methods. The denoising methods were evaluated through ratio to noise level (RNL), normalized root mean square error (NRMSE) and normalized correlation coefficient (NCC). In addition, the computation times for all denoising methods were also recorded. Based on RNL, NRMSE and NCC indexes, the performances of the denoising methods were analyzed through normalization based on the coefficient of variation (). Based on the current study, it is found that DWT performs well to denoise the electrical PD signal based on the RNL and NRMSE index while MA has a good denoising NCC and computation time index for acoustic emission PD signal

A grid-tied PV-fuel cell multilevel inverter under PQ open-loop control scheme

Power generating entities’ connection to utility grids requires power converters to achieve high efficiency and low injected current harmonic distortion. The control of the power converter plays a crucial role in the grid-tied power converter’s performance. Various control techniques for grid-tied inverters ranging from classical to intelligent are introduced in several exist. Evaluating the current state and trend in grid-tied power inverters and related control methods, research shows that most works in this area focus on grid integration using the close-loop and other advanced control approaches. This is because these control methods are preferred since they provide adequate performance in case of uncertainties in the system. This investigation can aprove that PQ open-loop control technique can operate sufficiently and cost-effectively in grid-tied renewable and alternative power systems under normal operating conditions. Hence, this paper aims to assess the performance of a centralized single-stage grid-tied three-level diode clamped inverter connected to a PV-Fuel cell unit. An active and reactive power open-loop control scheme is employed to operate the inverter and achieves a current harmonic distortion below 5%. The system comprises a 150 kW/700 V PV, a 150 kW/1400 V fuel cell, a 265 kW multilevel inverter operating at a rated voltage of 415 V, and an LCL filter. Two operating scenarios are adopted to investigate the system’s responses further. In the first scenario, a local load of 509.2 kW is supplied from the PV-fuel cell inverter. The load also receives the grid’s power to meet the demand as the PV-fuel cell inverter provides only 265 kW. Whereas in the other scenario, the PV-fuel cell unit provides power to supply a local load while transporting the surplus to the grid. The results reveal the developed model’s good performance with a current harmonic distortion of 0.33%

Investigation of Static Voltage Accumulation on Wind Turbine Blade in Atmospheric Wind speed Humidity and Temperature

Wind turbines are one of renewable energy sources. Wind turbines installed at wild open area such offshore, mountains and deserts are filled with air particles and flow of wind speed. During the wind flow throughout the wind turbines which rotates the turbine blades, there is friction between the air particles and the blade surface that leads the static voltage to accumulate on the blade surface causing upward streamers. Using fiberglass reinforced plastic (FRP) wind turbine blades by simulation and experimental method. The charged particle tracing with electrostatics and laminar flow with time-dependent used to determine the value of static voltage accumulation. Static voltage accumulation is influenced by various factors such as wind speed (1, 5, and 7 m/s), humidity (20, 50, and 70 %RH) and temperature (28, 35, and 48 oC) had tested and analyzed. Furthermore, the result obtained using the Finite Element Method (FEM) has shown a good agreement with the experimental result. It was observed that high flow velocity has a great tendency to charge the blade surface with 36.70%higher from 1 m/s to 7 m/s. Low relative air humidity increases the risk of static electricity 221.6 V at the of side of the blade when humidity is 20%. Moreover, increasing the air temperature from 28 to 48 degrees Celsius increases the voltage by 20%. Therefore, determining the need for statice voltages generated in the blade surface and the risk related to upward streamers is obliged to be evaluated as it is the essential ways in adopting the correct protection systems

Inactivation of mucose on bread by using plasma jet

This paper presents the application of cold plasma technology on bread. Plasma is a fourth state of matter apart from solid liquid and gas states. It possesses the same amount of negative and positive ions that are produced from the gas molecule that goes through the electrical breakdown process. Plasma can be produced by injecting high voltage through an electrode. This project aims to develop a plasma jet system that will be able to produce cold plasma with the help of argon as the working gas. Due to its multifunction purpose, cold plasma can be used in many different fields such as biomedical, textile manufacturing, surface modification, food packaging, and many more. In this study, plasma generated with higher voltage may reduce the occupation of mucose on the bread as compares to the control

Electrical tree inception voltage and propagation in XLPE containing silica nanofiller

This paper presents the tree inception voltage and electrical tree propagation in XLPE containing silica nanofiller. The concentration of silica nanofillers in XLPE was 0 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt% and 1.75 wt%. The needle plate electrodes were used to analyzed the tree inception voltage and electrical treeing propagation. The structure and the propagation length of electrical tree growth were analyzed after 20 min of tree inception voltage. The result of tree inception voltage and the electrical tree propagation in XLPE containing silica nanofiller was compared with pure XLPE composite. The silica nanofiller with the concentration of 1.5 wt% revealed the higher TIV and slower propagation of electrical tree in the XLPE nanocomposite

Effect of silica nanofiller in cross-linked polyethylene as electrical tree growth inhibitor

One of the main phenomena that contributes to the non-success of cable insulation made of cross-linked polyethylene (XLPE) is electrical treeing. To improve the XPLE cable insulation, the use of nanofiller has been introduced. Adding the nanofiller in the based composite offers better cable lifetime and resistance to deal with the cable failure. One of the potential nanofillers that can increase the insulation performance of XLPE cable is silica nanofiller. To this extent, the studies on silica nanofiller in XLPE are focusing on the impulse breakdown strength, dielectric loss, permittivity, space charge, alternating current (AC), and partial discharge. The studies reveal that the dielectric properties of the XLPE nanocomposite have significant improvement. Therefore, this work investigates the effect of various concentrations of silica nanofiller in XLPE composite as electrical tree inhibitor. The concentrations of silica nanofiller in XLPE were 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.5 wt%, and 1.75 wt%. The silica nanofillers have 96%-99% purity, 20-30 nm sizes and the shapes are spherical. As a result, the XLPE composite containing 1.5 wt% silica nanofiller demonstrate higher tree inception voltage and detaining the tree propagation speed, which could be considered as an inhibitor medium of electrical tree growt

診断技術開発の基礎としての環境調和型ガス絶縁媒体の部分放電特性および分解ガス分析の研究

九州工業大学博士学位論文 学位記番号: 工博甲第260号 学位授与年月日: 平成20年3月25日Chapter 1 Introduction|Chapter 2 Experimental setup and method|Chapter 3 Discharge properties and emitted electromagnetic wave spectrum in low vacuum region of vacuum interrupter|Chapter 4 Partial discharge properties and determination of gas pressure in vacuum interrupter based on partial discharge|Chapter 5 AC sparkover voltage properties and gas decomposition by-product analysis of CF3I under non-uniform electric field| configuration|Chapter 6 Summary|Appendix|Acknowledgment|List of publications九州工業大学平成19年