the electric power engineering handbook second edition

... resistance of the conductors and leads. ã Eddy losses. These losses are caused by the leakage field, and they are a function of the second power of the leakage field density and the second power of the conductor ... is placed in the field created by the first conductor as shown in Fig. 3.2, such that the flux lines link the second conductor, then a voltage is induced into the second conductor. The use of a ... increases the cooling and thereby the rating of the transformer without increasing the unit’s physical size. Ratings are determined based on the temperature of the unit as it coordinates with the cooling...

Ngày tải lên: 05/03/2014, 16:20

... system. The figure shows the Phoenix area 230-kV system, which interconnects the local power plants and the substations supplying different areas of the city. The circles are the substations and the ... to move out on the line to replace the spacer, or the line would have been lowered and the spacer replaced and the conductor strengthened. The obvious safety dilemma was whether the conductor ... erosion, which ages the insulator’s surface. 12. A change in the weather, such as the sun rising, reduces the wetting. As the insulator dries, the discharge diminishes. 13. The insulator will...

Ngày tải lên: 05/03/2014, 16:20

Ngày tải lên: 13/05/2014, 03:32

... pressure. The gas is ducted through the regenerator where the waste heat is transferred to the incoming air. The gas is then discharged into the ambient air through the exhaust stack. In effect, the ... reducing the performance gap between these two types of gas turbines. The gas turbine to date in the combined cycle mode is fast replacing the steam turbine as the base load provider of electrical power ... throughout the world. This is even true in Europe and the United States where the large steam turbines were the only type of base load power in the fossil energy sector. The gas turbine from the 1960s...

Ngày tải lên: 13/02/2014, 16:20

... increase the temperature and decrease the volume per the Brayton Cycle. The fuel is then added and the combustion takes place in the combustor, which increases both the temperature and volume of the ... interrupting the circuit either to turn the load on and off or to interrupt fault current. The first requirement is based on the full load current of the load. The second requirement is based on the maximum ... determined by the way the generator is connected to the power system. If the generator is connected directly to the power system, a resistor or inductor connected between the neutral of the generator...

Ngày tải lên: 05/03/2014, 16:20

... introductory network theory. He is currently the series editor for the Electrical Engineering Handbook Series published by CRC Press. In 1993 he was inducted into the Electrical Engineering Academy ... of Bus Admittance Matrix The first step in developing the mathematical model describing the power flow in the network is the formulation of the bus admittance matrix. The bus admittance matrix ... to the study of power systems; in fact, power flow forms the core of power system analysis. A power flow study is valuable for many reasons. For example, power flow analyses play a key role in the...

Ngày tải lên: 21/03/2014, 12:11

... installed either inside the GIS enclosure or outside the GIS enclosure (Fig. 5.4). The GIS conductor is the single turn primary for the CT. CTs inside the enclosure must be shielded from the electric ... switches are frequently used at the connection point of the GIS to the rest of the electric power network, not only in case the connected line is energized, but also because the fast-acting ground switch ... arresters, and connections to the rest of the electric power system) to match the electrical one-line diagram of the substation. A cross- section view of a 242-kV GIS shows the construction and typical...

Ngày tải lên: 21/03/2014, 12:12

... regulator is not the current that flows all the way from the regulator to the load center. The proper way to determine the line impedance values is to run a power- flow program of the feeder without the regulator ... and the voltage unbalance at the load. The line-to-ground voltages and line currents at the substation are: Solve Eq. (6.85) for the load voltages: The voltage unbalance at the load using the ... operating. From the output of the program, the voltages at the regulator output and the load center are known. Now the “equivalent” line impedance can be computed as: (6.108) In Eq. (6.108), the voltages...

Ngày tải lên: 21/03/2014, 12:12

... and the cosine of the phase angle between the two. Thus, the torque is also proportional to the power in the metered circuit. The device described so far is incomplete. In measuring a steady power ... of time is energy. In mathematical terms, power integrated over time is energy. The basic electrical unit of energy is the watthour. The basic unit of power is the watt. The watthour meter measures ... curve. Hanson, Andrew Electric Power Utilization” The Electric Power Engineering Handbook Ed. L.L. Grigsby Boca Raton: CRC Press LLC, 2001 â 2001 CRC Press LLC (N = 3), the meter must contain...

Ngày tải lên: 21/03/2014, 12:12

... known. However, these currents are not known. Rather, something is known about the complex power and voltage at each bus. The complex power injected into bus k of the power system is defined by the relationship ... approximating the partial derivatives of the real power equations with respect to the bus voltage magnitudes as zero. Similarly, the partial derivatives of the reactive power equations with respect to the bus ... reactive power are unknowns. The bus selected as the slack bus must have a source of both real and reactive power, since the injected power at this bus must “swing” to take up the “slack” in the solution....

Ngày tải lên: 21/03/2014, 12:12

... i.e., the impedance, at the relay location. The impedance per mile is fairly constant so these relays respond to the distance between the relay location and the fault location. As the power systems ... prevent the fault. Its primary purpose is to detect the fault and take the necessary action to minimize the damage to the equipment or to the system. The most common parameters which reflect the presence ... towards the trip zone of the relay, and may even encroach on it, then leave again. The unstable trajectory may pass through the entire trip zone of the relay. The relaying tasks are to detect, and then...

Ngày tải lên: 21/03/2014, 12:12

... of the voltages induced by the release of the charges bound either by the cloud or by the stepped leader are small compared with the voltages induced by the return stroke. Therefore, only the ... d ps is the distance from the shield wire to the phase conductor. Z 11 is the surge impedance of the phase conductor in the absence of the shield wire, Z 22 is the surge impedance of the shield ... voltage on the line. If the lightning has subsequent strokes, then the subsequent components of the induced voltage will be similar to one or the other of the four components discussed above. The magnitudes...

Ngày tải lên: 21/03/2014, 12:13

... importantly, a function of the transmission system reactance; the larger the reactance (for example, the longer or weaker the transmis- sion circuits), the lower the maximum power. 2H d dt TT r me ω =− d dt d dt r ω δ ω = 2 0 2 2 0 2 2 Hd dt TT me ω δ =− P EE X P e B T = ′ =sin ... applied to the system given in Fig. 11.3. The only difference in the two cases is that the fault clearing time has been increased for the unstable case. The arrows show the trace of the path followed ... into the vehicle as a result of the sudden push, and compare it with the energy needed to climb the hill. In this method, there is no need to track the position of the vehicle as it moves up the...

Ngày tải lên: 21/03/2014, 12:13

... foundation for their calculations, the performance of the state estimator depends on the accuracy of the measured data as well as the parameters of the network model. Fortunately, the use of all ... chosen so that the optimal solution was known a priori. The dashed line in the load forecast represents the maximum output of the 10 units. Before running the UC-GA, the user specifies the control ... minutes as the demand changes. The losses in the power system are a function of the generation pattern, and they are taken into account by multiplying the generator incremental costs by the appropriate...

Ngày tải lên: 21/03/2014, 12:13

... next day, i.e., the 24 outputs are the forecasts of the hourly loads of the next day. This ANN will be referred to as the “Regular Load Forecaster (RLF).” On the other hand, the second ANN forecaster ... weather parameters forecasts for the coming day ã Day type indices The difference between the two ANNs is in their outputs. The first forecaster is trained to predict the regular (base) load of the ... examples, called the training set, are applied to the ANN. The ANN learns by adjusting or adapting the connection weights through comparing the output of the ANN to the expected output. Once the ANN is...

Ngày tải lên: 21/03/2014, 12:13

... by knowing the value of the short-circuit current available at the secondary of the utility transformer supplying power to the establishment (building) and the series impedance in the electrical circuit ... switching event, there would be no power loss in the switch since either the current in the switch is zero (switch open) or the voltage across the switch is zero (switch closed) and the power loss ... across the load resistor is rather large and, in typical power supplies, such ripples are unacceptable. The current through the load is discontinuous and the current through the secondary of the...

Ngày tải lên: 21/03/2014, 12:13

Ngày tải lên: 21/03/2014, 12:13

Ngày tải lên: 21/03/2014, 12:13

Ngày tải lên: 21/03/2014, 12:13