Papers by Keyword: Power Loss

Abstract: Renewable energy sources (RES) offer outstanding attributes namely environmental-friendly and reduction in the cost of Grid system. Global power firm have embraced RES in generating electrical energy. RES, notably wind energy lessens electrical power losses on the network, nevertheless, RES incorporation into the network has adverse effect on the entire network. This research bequest critical investigation and comprehensive evaluation of reverse power flow (RPF)due to the outcome of vigorous and increased RES penetration to the Electrical Power Network. Matlab/Simulink Software is employed to carry out critical investigation on eight-bus electrical power network. The Matlab simulation was carried out with and without RES connection to the electric power network. Zones are employed for potent and effective investigation and evaluation of the network. The outcome of evaluation and analysis in sub-networks and the zones were carefully compared. The result show that RPF happens at all levels of electrical power networks, though, the penetration levels are not the same. It was revealed that RPF at the zone directly linked with the RES is higher compared with other zones.

Abstract: The efficiency of solar systems is affected by environmental factors, especially in coastal areas where dust accumulation on solar modules reduces output power. The growth of renewable energies has reduced dependence on fossil fuels, with photovoltaic solar energy being one of the most used due to its easy installation. However, fouling of solar modules can lead to losses in power generation. It is surprising that the sea and ocean spray are significant sources of dust. This study focuses on quantifying how sea fouling affects efficiency and causes power losses in solar modules in the coastal region of Honduras. In this study, these losses were quantified during 14 days in a month, making nine daily measurements on rooftop solar modules, leaving two reference modules (clean) and two test modules (dirty), finding average daily losses of up to 5.91% in monocrystalline module and 6.18% in polycrystalline module. Temperature, wind speed and particles of 0.3µm, 2.5µm and 10µm accumulated in the modules were related to the average power losses. It is highlighted that the 10µm particles are the most related to these losses, with an R2=0.9404 in monocrystalline and a R2=0.9191 in polycrystalline. These findings are fundamental for the design and installation of photovoltaic systems in coastal areas, as they highlight the importance of the losses in the design and installation of photovoltaic systems in coastal areas.

Abstract: This paper focuses on how to define and integrate the system level and power module level with optimal conditions in SiC and Si-IGBT. To investigate the above situation, we compare the performance of SiC and Si-IGBT in power module and system level at different ambient temperatures. At the same maximum junction temperature 150°C and ambient temperature at 25°C and 80°C, it found that SiC type electrical resistance, maximum endurable current, and voltage could be better than the IGBT type power module above 20%. On the other hand, the simulation of three-phase inverter at different switching frequency such as 10kHz, 15kHz, 20kHz, 30kHz and it had been observed that the power loss of SiC inverter are 78% less for 10kHz switching frequency; 82% less for switching frequency at 15kHz; 85% less for 20kHz of switching frequency; 89% less for switching frequency at 30kHz in the Si-IGBT three-phase SPWM inverter at ambient temperature 80°C.

Abstract: This paper indicates the early experimental results of a Ricardo model CNG engine R&D activity in Vietnam, the experiments were mainly focused on the effects of compression ratio on operating parameters of the tested single cylinder CNG engine particularly designed and fabricated for varying compression ratio purpose. The compression ratio was set in the range of ε = 10 to 15 with the change step of Δε = 1. For each compression ratio, the engine speed were varried from 1000rpm to 2200rpm with the change step of Δn = 200. The early spark angle was also changed to find out the maximum break torque. The limitation of compression ratio and engine speed at each operating point was determined by vibration signal and abnormal sound. The experimental results indicated the early spark angle must be adjusted premature in case of compression ratio and/or engine speed enhenced. Especially, the portion of indispensable power to perform the compression stroke is smaller in comparison with the portion to execute the both strokes of intake and exhaust. In addition, the shape of combustion chamber affected strongly the operating characteristics also found in this study.

Abstract: Currently, nanofluids have been found to have enriched physical and thermal properties such as thermal conductivity, viscosity and convective heat transfer coefficients. The aim of this research is to analyse the performance characteristics of punga oil and plastic oil based nanolubricants. The nanoparticle of graphite with 0.1% weight was added to the base oils. Hydraulic oil of VG32 is used as standard oil to compare the performance with the nanolubricants. Basic properties such as viscosity, flash and fire point were measured for the prepared nanolubricants. Coefficient of friction for the selected oils was measured with help of reciprocating friction monitor and load wear index was also measured with the help of four ball tester. The performance of these oils for load ball bearing lubrication was carried out numerically with the help of Comsol software and its analytical validation was done with the help of MATLAB software. From the observed results it was found that, the power loss was decreased by about 77.4% and 78% by plastic oil and plastic oil based nanolubricant respectively and load carrying capacity was also decreased by about 78.3% and 78.8%.

Abstract: This paper discusses the optimal Distributed Generator (DG) coordination using the Particle Swarm Optimization (PSO) technique where the DG output and location are determined simultaneously. Furthermore, this study analyzes both single DG and multiple DGs configurations. The influence of DG Power Factor (PF) to the optimal DG placement and the DG output are investigated by varying the DG PF values. Specifically, the PF were configured to five values, which are 0.8, 0.85, 0.9, 0.95 and 1.0. From the results, the optimal DG placements are similar, regardless of the PF condition. For example, in the single DG unit experiment, the optimal DG location is at bus 6 whilst in the triple DG units test, the optimal locations are at busses 14, 24, and 30. In contrast, the value of PF significantly influences the optimal DG output and power loss reduction. This study concludes that the design with three DGs where their PFs are configured to 0.8 has the least power loss.

Abstract: The pair between slipper and swash-plate is an important friction pair in the axial piston pump. Due to quick relative velocity, alternating load, numerous slippers, and high contact pressure between the friction surfaces, the wear-out and fatigue failure constantly occurs, which is one of the key factors affecting reliability of the piston pump. It is of fundamental significance to investigate the mechanism of slipper power loss and to find an appropriate method to improve the lubrication of the slipper. Here, the model of friction power loss between slipper and swash-plate is established, and the friction power loss between slipper and swash-plate is solved and comparatively analysed. Finally, the correctness of theoretical analysis and simulation results are verified by experiments.

Abstract: The magnetostriction and magnetic properties of electrical steel are depended on the external stress. In this paper, a noncontact magneostriction measuring system using laser displacement meter with high resolution of 10 nm has been built. The grain-oriented electrical steel with dimensions 500 mm × 100 mm × 0.3 mm was measured between 20 MPa and-20 MPa. The magnetostriction and magnetic properties were highly sensitively to stress. A clear relationship between power loss and magnetostriction under stress was found, and the underlying mechanism has been discussed.

Abstract: A transmission efficiency calculation model of planetary geared reducer was proposed in this paper. The power losses of meshed surfaces of sun-planet gears and planet-ring gears were analyzed in detail. Finally, the mechanical power losses and transmission efficiency of the planetary gear reducer were simulated to illustrate the influence of rotational speed and torque on mechanical power loss and transmission efficiency.

Abstract: For air fan and water pump load, variable voltage and variable frequency (VVVF) energy-saving effect is very significant. This paper focuses on the study of energy-saving effect implemented by converter of the motor at constant torque load. In order to analyze the influence of the loss controlled by the voltage and frequency in detail, we obtain the theoretical calculation formula of total loss and input power by means of the classification of power loss of asynchronous motor under the cantilever equivalent circuit, take a 5.5kW motor as an example, a series of experimental schemes are designed and the general change rules of total loss and input power are studied respectively with the different voltage to frequency ratio. The results show that the measured values are basically accordant with the theoretical calculation value. On different conditions of voltage frequency ratio, optimal value exists in the total loss instead of input power.