Papers by Keyword: Power

Abstract: The longevity forecast is proposed to be implemented on the basis of models of degradation theory. The theory of degradation is developed as a general energy method for estimating the longevity of objects. It is based on the law of conservation of energy. To analyze the longevity of urban environment, it is proposed to adopt the simplest model of theory of degradation. The proposed work provides an explanation for the description of proposed model. The urban environment is divided into a number of simpler systems. The more the degree of system separation into simpler ones, the more accurately one can describe the behavior of the entire system in time. Each simple system is described by the simplest model of degradation theory. The general behavior of the system is understood as a simple sum of individual degradation models. A feature of the proposed theory is that the simplest model can describe the entire system or the sum of its individual parts at once. The model makes it possible to consider the issue of equalizing the longevity of individual systems. The analysis of durability of a multicompartment building is taken as an example. In terms of analyzing the given example, individual stages of systems operation, that are still subject to discussion, are identified.

Abstract: A comprehensive comparison of 3C-SiC and 4H-SiC power MOSFETs was performed, aimed at quantifying and comparing the devices’ on-resistance and switching loss. To this end, the relevant material parameters were collected using experimental data where available, or those obtained by simulation. This includes the bulk mobility as a function of doping density, the breakdown field as a function of doping and the MOSFET channel mobility. A device model was constructed and then used to calculate the on-resistance and breakdown voltage of a properly scaled device as a function of the doping density of the blocking layer. A SPICE model was constructed to explore the switching transients and switching losses. The simulations indicate that, for the chosen material parameters, a 600 V 3C-SiC MOSFET has an on-resistance, which is less than half that of a 4H-SiC MOSFET as are the switching losses in the device.

Abstract: Diamond films and diamond/graphite composite films have excellent wear resistance, it can be used as the protective coating to effectively improve the parts life and performance. The micro crystalline diamond films, nanocrystalline diamond films and diamond/graphite composite films were prepared on sic substrate by microwave plasma chemical vapor deposition on different power, pressure and CH4 concentration growth parameters. The films surface characteristics were research by SEM and Raman spectrometer. The results indicate that the diamond grain size and content decreased and graphite content increased with CH4 concentration increasing on constant microwave power and cavity pressure; the diamond grain size decreased and graphite constant increased with cavity pressure increasing on constant microwave power and CH4 concentration.

Abstract: The integration of power and vapor absorption refrigeration cycle overcomes the disadvantages of power used for the compression refrigeration and also produces additional power for other purposes (Low pressure turbine). The integration is done by making the heat exchanger and generator as common and separate super heater and reheater is used to run the high pressure turbine (HPT) and low pressure turbine (LPT). The maximum total power output of 69.78 kW and 31.86 kW is obtained for HPT and LPT at the atmosphere temperature 30 °C and separator temperature 180 °C. At the same collector exit and atmosphere temperature shows the maximum cooling output of 188.88 kW. The additional advantages of integrating the power and cooling cycle’s shows the choice of choosing the need of only power only cooling and both power and cooling. The analyses are done for various separator temperature and strong solution concentration.

Abstract: The scientific study of detonation stretches over a century and the potential to harness detonations for propulsion and power was recognized for almost as long. It is only in the past two decades that detonation applications have received intense attention. Attractions for utilizing detonations include the higher theoretical thermodynamic efficiency compared to deflagration-based systems, high power-to-weight or volume ratio and lack of moving parts. Despite these attractive features, a number of fundamental physics and engineering challenges must be overcome before such systems can be practical. Some of these include the ability to achieve consistent and reliable detonations in a practical arrangement, understanding of the unsteadiness, and integration with ancillary systems. Illustrations will be provided on how some of these issues were understood and overcome. Potential challenges are also highlighted.

Abstract: This paper is devoted to the study of distributed generation units impact on pricing on the wholesale power energy market. The paper deals with results the analysis of the wholesale electricity market and power. This analysis is necessary for proper impact assessment of distributed generation units on a total optimization. Optimization calculations performed for the real power system, when distributed generation units operating the basic and peak modes, as well as the cost-effectiveness of this modes.

Abstract: The objective of this work is to increase the power of the two wheeler miniature engines (100cc to 250cc) by supercharging the vehicle using the suspension system. For this purpose a design is made to extract compressed air from the suspension system. It has been successfully shown that the air can be extracted from the suspension system, stored and then fed into the engine similar to supercharger or turbocharger, and the engine power can be improved using this free energy.

Abstract: In this paper a method of optimization of the quantity of diesel power generating units according to the schedule of electric loads based on the undersupply expectation and the power supply interruption, emergency and planned stops of diesel generators is proposed.

Abstract: This chapter starts with a background about concentrating solar power systems and thermal energy storage systems and then a detailed literature review about concentrated solar power systems and supercritical Brayton carbon dioxide cycles. Next, a mathematical model was developed and presented which generates and optimizes a heliostat field effectively. This model was developed to demonstrate the optimization of a heliostat field using differential evolution, which is an evolutionary algorithm. The current model illustrates how to employ the developed model and its advantages. The optimization process calculates the optical performance parameters at every step of the optimization considering all the heliostats; thus yields accurate results as discussed in this chapter. On the other hand, complete mathematical model of supercritical CO₂ Brayton cycles when integrated with solar thermal power tower system was presented and discussed.

Abstract: Flux switching machines (FSMs), new type of electric machines with unique operating principles have been introduced and published recently. FSMs contain armature and excitation sources on the stator with robust rotor structure. According to rotor structure FSMs can be classified into two types namely salient pole rotor and segmental pole rotor. Various topologies have been studied and published using both rotor structures, however salient pole rotor has a demerit of less torque generation due to longer flux path resulting flux leakage surrounding the rotor. In this paper a new structure of hybrid excitation FSM (HEFSM) with segmental rotor is proposed and a comparative analysis with the invented field excitation FSM (FEFSM) and permanent magnet FSM (PMFSM) is presented. Initially, coil arrangement tests are examined to confirm the operating principle of HEFSM with segmental rotor. Moreover, the cogging torque, induced voltage, magnetic flux, torque at various armature current densities and power characteristics are observed based on 2D-finite element analysis (FEA).