Power system engineering
 
Category: Power system engineering
Wind energy is among the world’s fastest-growing sources of energy. During the last decade, wind energy growth rates worldwide averaged about 30 percent annually.1 In the last three years, the U.S. and Texas wind energy markets also have experienced a rapid expansion of capacity. In 2007, for example, U.S. wind power capacity grew by 43 percent, while Texas’ rose by 57 percent.
1301 days ago
 
1301 days ago
 
It is important to understand that solar thermal technology is not the same as solar panel, or photovoltaic, technology. Solar thermal electric energy generation concentrates the light from the sun to create heat, and that heat is used to run a heat engine, which turns a generator to make electricity.
1301 days ago
 
The sun is an inexhaustible source of energy. Solar energy is radiant energy from the sun caused by nuclear fusion in the sun’s core. The sun’s radiant energy reaches the earth in rays of sunlight. Solar energy in the form of heat and light sustains life on earth. Solar energy can also be collected, stored and put to work by converting it to pollution-free thermal (heat) energy and electricity. Less than 1% of the world’s total electricity production comes from solar power. Current and future technologies to harvest the sun’s energy could substantially increase this percentage. Interest and development of solar technology fluctuates as it competes with the varying costs of fossil fuels.
1301 days ago
 
The standard of living of the people of any country is considered to be proportional to the energy consumption by the people of that country. In one sense, the disparity one feels from country to country arises from the extent of accessible energy for the citizens of each country. Unfortunately, the world energy demands are mainly met by the fossil fuels today. The geographical non equi-distribution of this source and also the ability to acquire and also control the production and supply of this energy source have given rise to many issues and also the disparity in the standard of living.
1301 days ago
 
The oceans of the world contain vast amounts of energy. In particular, two dierent forms of ocean energy oer possible energy resources: heat energy (or ocean thermal energy) and the energy of waves and ocean currents.
1301 days ago
 
First-generation tools are far from disappearing from the Internet landscape. E-mail continues to be a viable tool for tandem learning and classroom exchanges. Now that most e-mail programs support formatted text and graphics, e-mail is more attractive and versatile than in the days of plain ASCII. Multimedia can now be embedded directly in messages and non-Roman characters are more easily supported. However, many instructors have increasingly turned to discussion forums as the principal tool for written exchanges among class members
1301 days ago
 
Biomass materials are used since millennia for meeting myriad human needs including energy. Main sources of biomass energy are trees, crops and animal waste. Until the middle of 19th century, biomass dominated the global energy supply with a seventy percent share (Grubler and Nakicenovic, 1988). Among the biomass energy sources, wood fuels are the most prominent. With rapid increase in fossil fuel use, the share of biomass in total energy declined steadily through substitution by coal in the nineteenth century and later by refined oil and gas during the twentieth century.
1301 days ago
 
In general, the loads which have poor power factor, unbalance, harmonics, and dc components require compensation. These loads are arc and induction furnaces, sugar plants, steel rolling mills (adjustable speed drives), power electronics based loads, large motors with frequent start and stop etc. All these loads can be classified into three basic categories. 1. Unbalanced ac load 2. Unbalanced ac + non linear load 3. Unbalanced ac + nonlinear ac + dc component of load. The dc component is generally caused by the usage of half-wave rectifiers. These loads, particularly nonlinear loads generate harmonics as well as fundamental frequency voltage variations. For example arc furnaces generate significant amount of harmonics at the load bus.
1301 days ago
 
Hyundai Ideal Electric Co. has built synchronous condensers for over fifty years. Our expertise, combined with high quality materials and manufacturing processes, results in a reliable, cost-effective condenser with high performance and low operating costs. Synchronous condensers are fundamentally a synchronous motor that is not connected to any driven load.
1301 days ago
 
A typical deepwater installation operation consists of 4 main phases: liftoff from the deck of a transport barge, lowering through the wave zone, deepwater lowering/lift operation, touchdown on seabed and retrieval. During the deepwater lifting operation, a heave compensation system can be employed to mitigate the vertical resonant motion of the lifted equipment which reduces the dynamic loads in the hoisting wire system. There are 3 types of heave compensators that have been used in deepwater lifts: Passive, active and combined heave compensators.
1302 days ago
 
Power factor is defined as the ratio of real power to apparent power. This definition is often mathematically represented as kW/kVA, where the numerator is the active (real) power and the denominator is the (active+ reactive) or apparent power. Though the definition is very simple, the concept of reactive power is vague or confusing even to many of those who are technically knowledgeable.
1302 days ago
 
The power quality of distribution systems has a drastic effect on power regulation and consumption. Johan Lundquist of the Chalmers University of Technology in Goteberg, Sweden put it best, stating “The phrase ‘power quality’ has been widely used during the last decade and includes all aspects of events in the system that deviates from normal operation.”1 This has been especially true after the second half of the 20th century when new types of electronic power sources caused distortion in waveforms of the power system.
1302 days ago
 
A very common application of symmetrical components is in calculating currents arising from unblanced short circuits. For three-phase systems, the possible unbalanced faults are: 1. Single line-ground, 2. Double line-ground, 3. Line-line. These are considered separately.
1302 days ago
 
A system of three unbalanced phasors can be resolved in the following three symmetrical components: • Positive Sequence: A balanced three-phase system with the same phase sequence as the original sequence. • Negative sequence: A balanced three-phase system with the opposite phase sequence as the original sequence. • Zero Sequence: Three phasors that are equal in magnitude and phase.
1302 days ago
 
A transmission line has four parameters -- series resistance and inductance, and shunt conductance and capacitance. These are uniformly distributed along the line. In the derivation of transmission line equations the following assumptions are usually made: The line is transposed (or symmetrical), and the three phases are balanced. In practice this is not entirely true but the unbalance and departure from symmetry are small. The line can therefore be analyzed on a per-phase basis
1302 days ago
 
APOWER SYSTEM is predominantly in steady state operation or in a state that could with sufficient accuracy be regarded as steady state. In a power system there are always small load changes, switching actions, and other transients occurring so that in a strict mathematical sense most of the variables are varying with the time. However, these variations are most of the time so small that an algebraic, i.e. not time varying model of the power system is justified.
1302 days ago
 
Fault studies involve determining the bus voltages and bus currents during various types of faults. Faults in power systems can be classified into balanced (symmetrical) faults and unbalanced faults. Balanced faults involve three phase faults whilst unbalanced faults involve single line to ground faults, line to line faults and double line to ground faults. In this chapter we only focus on balanced three phase faults. Three phase fault information is used to select and set phase relays and also to ascertain the rating of protective switchgear
1302 days ago
 
As poultry production systems become increasingly automated, monitoring systems are being integrated with control systems to provide growers with real-time and historical information on how various systems such as environment control, feeding, egg handling, and water are performing. The use of buildings that are 400 or more feet in length and which may be from hundreds of feet to miles away from the farm office presents a number of technical problems to the farm manager who wants to carefully monitor and control the conditions in poultry houses.
1302 days ago
 
 Definition: power system security is the ability of the system to withstand disturbances without unduly impacting the service to the loads or its quality  In security applications, we refer to the disturbances of interest as contingencies  In power system operations, security assessment analyzes the vulnerability of the system to a set of postulated contingencies on a real – or near – real – time basis
1302 days ago
 
• Generation Capacity must be greater than load • Transmission must not be overloaded • Voltages must be within limits • Must be able to withstand loss of generator • Must be able to withstand loss of transmission line • Must not lose stability during short-circuit
1302 days ago
 
The unit commitment (UC) has been a subject with increasing interests after 1998. It determines an optimal schedule of units and the amount power generation to be used to meet the demand over a future period. After the liberalization of the electricity industry, in most of countries, the unit commitment problem is solved as a market problem based on bid prices, instead of the costbased minimization of the classical model.
1302 days ago
 
Transmission systems are becoming increasingly stressed because of growing demand and because of restrictions on building new lines. However, most high voltage transmission systems are operating below their thermal rating due to such constraints as stability limits. EPR£ is pioneering flexible ac transmission system (FACTS) technology to make it possible to load lines at least for some contingencies up to their thermal limits without compromising system reliability.
1302 days ago
 
EA63-5 is an automatic voltage regulator (AVR) for AMG synchronous generator industrial application series. The AVR is typically supplied by a single-phase auxiliary winding wound into the stator slots. It also can be supplied by permanent magnet generator
1302 days ago
 
The basic role of ALFC is: 1. To maintain the desired megawatt output power of a generator matching with the changing load. 2. To assist in controlling the frequency of larger interconnection. 3. To keep the net interchange power between pool members, at the predetermined values.
1302 days ago
 
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