power generation refrigeration and liquefaction

... maintenance and cost advantages found with power fuses Protection and control devices, circuit breakers, and station batteries are required The overcurrent relays are a small part of the total cost and ... load currents during peak and emergency conditions, performing coordination studies that include source and low side protection equipment, and expected transformer size and winding configuration ... aging, contamination, cracking, internal moisture, and loss of oil can all cause a bushing to fail Two other possible reasons are vandalism and animals that externally flash over the bushing Transformer...

Ngày tải lên: 21/03/2014, 12:08

... If above, the reverse power gets as low as 0.2 to 2% of the rated power and a sensitive reverse power relay is then needed With steam turbines operating at full vacuum and zero steam input, motoring ... above a small set-value SET_4 and the negative and zero sequence currents I2 and I2 not exceed a small set-value SET_3, then a fuse failure condition will pick up to one and remain in that state thanks ... 95TP102, 1995 IEEE Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems, ANSI=IEEE 242–1986 Ilar, M and Wittwer, M., Numerical generator protection offers...

Ngày tải lên: 21/03/2014, 12:08

... location As the power systems become more complex and the fault current varies with changes in generation and system configuration, directional overcurrent relays become difficult to apply and to set ... multiphase fault between phases x and y, Ex À Ey ¼ Z1 Ix À Iy (3:1) where x and y can be a, b, or c and Z1 is the positive sequence impedance between the relay location and the fault For ground distance ... Transf Open zone generator lead bus Closed zone FIGURE 3.1 Closed and open zones of protection (From Horowitz, S.H and Phadke, A.G., Power System Relaying, 2nd ed., 1995 Research Studies Press, U.K...

Ngày tải lên: 21/03/2014, 12:08

... in time, the process of power system cascading may start, leading to power system separation When a power system separates, islands with an imbalance between generation and load are formed One ... point Point of voltage collapse Q Active power margin P Reactive power margin FIGURE 4.2 Relationship between voltages, active and reactive powers of the load and voltage collapse Parameters based ... operating conditions such as voltage profile and generation dispatch, coordinating relays and controls, and load shedding Most utilities rely on planning and operation studies to guard against voltage...

Ngày tải lên: 21/03/2014, 12:08

... and is removed separately for some others The power system generated signals are transients depending on fault location, the fault incidence angle, and the structure of the power system The power ... in time and Eq (5.44) represents the measurements The terms wk and vk are discrete time random processes representing state noise, i.e., random inputs in the evolution of the parameters, and measurement ... state x, and recursively updates the estimate of state The initial assumption about the state is that it is a random vector independent of the processes wk and vk and with a known mean and covariance...

Ngày tải lên: 21/03/2014, 12:08

... reclosure, and delayed breaker failure response for permanent faults upon reclosure, and a ‘‘stuck’’ breaker In Fig 6.3 two waveforms are shown that depict adequate carrier response for internal and ... ‘‘off ’’ initially and cut ‘‘on’’ shortly after fault initiation It stayed ‘‘on’’ for a few cycles after the fault cleared and stayed ‘‘off ’’ all during the reclose ‘‘dead’’ time and after restoration ... This restrike cannot be extinguished and will last until the oil becomes badly carbonized and a subsequent fault occurs between the bus breaker terminal and the breaker tank (ground) In Fig 6.15...

Ngày tải lên: 21/03/2014, 12:08

... Design and Operation For reliable service, a power system must remain intact and be capable of withstanding a wide variety of disturbances Owing to economic and technical limitations, no power ... rotor angle instability and voltage instability go hand in hand One may lead to the other, and the distinction may not be clear However, distinguishing between angle stability and voltage stability ... rejections and system disturbances, IEEE Trans., PAS-100, 5, 2471, 1981 Kundur, P., Power System Stability and Control, McGraw-Hill, New York, 1994 Kundur, P and Morison, G.K., A review of definitions and...

Ngày tải lên: 21/03/2014, 12:08

... relationship and describes the transmitted power as a function of rotor angle It is clear from Eq (8.9) that the maximum power is a function of the voltages of the generator and infinite bus, and more ... maximum power Figure 8.3 shows that for a given input power to the generator Pm1, the electrical output power is Pe (equal to Pm) and the corresponding rotor angle is da As the mechanical power ... balanced generation and load Some load shedding or generation tripping may also be required in selected islands In the event of a disturbance, instability can be prevented from propagating and affecting...

Ngày tải lên: 21/03/2014, 12:08

... Alvarez, O., and Wu, C., Eigenvalue and frequency domain analysis of the intermountain power project and the WSCC network, IEEE Trans Power Systems, 238–244, February 1991 Pourbeik, P and Gibbard, ... of a power system and so must take its place in line along with economy, reliability, security, operational robustness, environmental effects, public acceptance, voltage and power quality, and ... J., and Fortin, S., A minimal realization approach to reduced-order modeling and modal analysis for power system response signals, IEEE Trans Power Systems, 8(3), 1020–1029, 1993 Kundur, P., Power...

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... power sources Availability of reactive power supplied by generators, synchronous condensers, and static-var compensators and its sensitivity to variations in load bus active and= or reactive power ... Van Cutsem, T., and Vittal, V., Definition and classification of power system stability, IEEE Transactions on Power Systems, 19, 1387–1401, 2004 Lof, P.-A., Smed, T., Andersson, G., and Hill, D.J., ... reactive power demand (or injection) at the receiving end 0.2 while maintaining the real power and the sending end voltage constant The relation between the receiv(1) (2) ing end voltage and the...

Ngày tải lên: 21/03/2014, 12:08

... Sauer, P.W., and M.A Pai, Power System Dynamics and Stability, Prentice Hall, New York, 1998 Tavora, Carlos J., and Smith, O.J M., Characterization of equilibrium and stability in power systems, ... Institute of Scientific and Technological Information and the Academy of Sciences of the USSR (in Russia) Criteria of Stability of Electric Power Systems Electric Technology and Electric Power Series, ... Moscow, 1971 (in Russian) Anderson, P.M., and Fouad, A.A., Power System Control and Stability, IEEE Press, New York, 1994 Athay, T., Sherkat, V.R., Podmore, R., Virmani, S., and Puech, C., Transient...

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... two 330-MW units and two 700-MW units The microprocessor-based controller measures rotor speed and generator power and computes acceleration and angle Tripping of 16–100% of plant generation is ... mechanical power characteristic and the electrical power characteristic Normal stable operation is at d0 For example, a small increase in mechanical power input causes an accelerating power that ... portions of a power system 12.2 Concepts of Power System Stability Controls Figure 12.5 shows the general structure for analysis of power system stability and for development of power system stability...

Ngày tải lên: 21/03/2014, 12:08

... equivalent circuit, and Ll represent the resistance and leakage inductance of the generator stator, Lad and Laq represent the mutual inductance between stator and rotor, and the remaining elements ... (OEL) Power transformer Terminal voltage and current Voltage sensing and compensation Underexcitation limiter (UEL) Generator flux (Volts/Hertz) limiter Power system stabilizer FIGURE 13.4 Power, ... for Power) , 105(1), October 1983, 865–869 Standard load models for power flow and dynamic performance simulation, IEEE Transactions, PWRS10, August 1995, Static Var compensator models for power...

Ngày tải lên: 21/03/2014, 12:08

... both its network performance, and its performance as an RMS transducer for steady stand and dynamic information on the power system All of these are major issues, and attention here is focused ... the data And, expanding upon Rule #2, for any large power system we have Rule #4 Procedures and toolsets for analysis of the WAMS database must permit integrated analysis of – Measured power system ... American Electric Power Company Arizona Public Service Company British Columbia Hydro and Power Authority Bonneville Power Administration Pacific Northwest National Laboratory Western Area Power Administration...

Ngày tải lên: 21/03/2014, 12:08

... References Anderson, P.M and Bose, A., A probabilistic approach to power system stability analysis, IEEE Transactions on Power Apparatus and Systems, PAS-102(8), 2430–2439, August 1983 Anderson, P.M and ... Ribbens-Pavella M and Evans, F.J., Direct methods for studying dynamics of large-scale electric power systems—A survey, Automatica, 21(1), 1–21, 1985 Sauer, P.W and Pai, M.A., Power System Dynamics and Stability, ... references (Anderson and Fouad, 1993; Kundur, 1994; Sauer and Pai, 1998) Additional issues are often important in DSA analysis as discussed in the following section 15.8 Criteria and Methods...

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... Colorado 52 IEEE=ANSI Standard C50.13, Standard for Cylindrical-Rotor 50 and 60 Hz, Synchronous Generators Rated 10 MVA and Above, 2005 53 Ramey, D.G., Sismour A.C., and Kung, G.C., Important ... turbine-generator damage from power system dynamic interaction For these reasons, methods have been developed to identify and analyze the potential for power system dynamic interaction and countermeasures ... the power system, the generators in the system, and the mechanical model of the turbine-generator being studied 16.2.5.3.1 EMTP Power System Model Three-phase circuits, a neutral circuit, and...

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... interchange error and frequency error and represents the power imbalance between generation and load at any instant This ACE must be filtered or smoothed such that excessive and random changes in ... angles, and power flows for all components in the system; and reports overload conditions Power flow: Determines the steady-state conditions of the power system network for a specified generation and ... for that particular demand, and this calculation is done every few minutes as the demand changes The losses in the power system are a function of the generation pattern, and they are taken into...

Ngày tải lên: 21/03/2014, 12:08

... through the forces of supply and demand Economic theory and common sense tell us that if the total supply is high and the demand is low, the price is likely to be low, and vice versa If the price ... Sheble and Fahd (1994) and Wood and Wollenberg (1996) Another heuristic technique that has shown much promise and that offers many advantages (e.g., time-to-solution for large systems and ability ... which is primarily determined by fuel cost and usage Fuel usage is closely related to generation level Very often, the relationship between power level and fuel cost is approximated by a quadratic...

Ngày tải lên: 21/03/2014, 12:08

... i and bus j, gij and bij are the conductance and susceptance of line i-j, respectively, and gish and bish are the shunt conductance and susceptance at bus i, respectively Using Eqs (19.4) and ... performs data acquisition and remote control of a power system Energy Management System (EMS)—A computer system that monitors, controls, and optimizes the transmission and generation facilities with ... Applications DataBase State Estimation Automatic Generation Control (AGC) Interchange Scheduling Power System Applications Power Flow Optimal Power Flow Contingency Analysis Short Circuit Analysis...

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... specified power demand occurs), the practically observed version of the standard OPF solution will have a higher total power demand, and hence a higher fuel cost, and total revenue, and net revenue ... OPF solution and hence there will be more cases with a decrease in the power demand, fuel cost, and total and net revenues in the observed version of the results than for its standard counterpart ... state of the power system changes continuously and can change abruptly during emergency conditions The changes involve the evolution of bus active and reactive power generation and loads with...

Ngày tải lên: 21/03/2014, 12:08