exploration transmission and distribution setup of natural gas in pakistan

... Wickings EJ, BarreSinoussi F, Georges AJ, Georges-Courbot MC: Phylogenetic analysis of SIV and STLV type I in mandrills (Mandrillus sphinx): indications that intracolony transmissions are predominantly ... the known modes of transmission for STLV-1; mainly from mother to child through breast-feeding In order to gain new insights on the timing of SFV infection, we undertook a longitudinal study with ... freeranging colony of monkeys, i e a group of 38 macaques (mostly adults) living in a temple in Central Bali, Indonesia In this case, the seroprevalence for FVs was of 89.5%, reaching 93% in adults...

Ngày tải lên: 13/08/2014, 09:21

... Hindu and Muslim faiths British rule of the Indian sub-continent ended in 1947, but the region was partitioned into two separate nations, India and Pakistan, with India getting the majority of ... ordinary persons, which helps in understanding their issues Livingston and Lunt (1994) confirm this argument by stating that the enlarging scope of media and its access is deeply integrated into ... 24 Selection of MoI played a central role in the independence movement of Pakistan in terms of nation-building and ethnic management, by declaring Urdu to be the language of Muslims in the country...

Ngày tải lên: 22/12/2014, 16:41

... to be between 95% and 105% of nominal on the subtransmission system during all-lines -in operation and between 90% and 110% of nominal following a first contingency Each element in the power delivery ... System Planning and Efficiency Initiatives Transmission and Distribution Planning Criteria Subtransmission GMP’s standard subtransmission voltages are 34.5 kV, 46 kV and 69 kV Using the subtransmission ... System Planning and Efficiency Initiatives Transmission and Distribution Planning Criteria Subtransmission GMP’s standard subtransmission voltages are 34.5 kV, 46 kV and 69 kV Using the subtransmission...

Ngày tải lên: 09/12/2015, 10:20

... resulting simplification of purchasing, stocking, installation, operation and maintenance practices, including the training and work practices of personnel and the selection and operation of equipment ... of service connections may be reduced in size toward the end of the main Practical problems of purchasing, stocking and handling, of connecting conductors of several sizes, etc., make it economically ... their roles in the delivery of power, in small and large quantities, to homes and offices, farms and factories They meet the needs of nontechnical people, including the legal and financial sectors,...

Ngày tải lên: 18/02/2014, 22:20

... contacts, insulation tracking, overheating, or contamination of the insulating oil Transformer bushings are the third most likely cause of failure General aging, contamination, cracking, internal ... operating on inrush include detection of current harmonics and zero current periods, both being characteristics of the magnetizing inrush current The former takes advantage of the presence of harmonics, ... restraint to block the relay during inrush conditions may result in a significant slowing of the relay during heavy internal faults due to the possible presence of second harmonics as a result of...

Ngày tải lên: 21/03/2014, 12:08

... are represented in Fig 2.2 For a stator winding, as shown in Fig 2.3, the restraint quantity will very often be the absolute sum of the two incoming and outgoing currents as in: ß 2006 by Taylor ... Protection and Coordination of Industrial and Commercial Power Systems, ANSI=IEEE 242–1986 Ilar, M and Wittwer, M., Numerical generator protection offers new benefits of gas turbines, International Gas ... voltage can be integrated in order to get an estimate of the flux Assuming a sinusoidal voltage of magnitude Vp and frequency f, and integrating over a positive or negative half-cycle interval: f¼...

Ngày tải lên: 21/03/2014, 12:08

... specific situations Operating Voltages Transmission lines will be those lines operating at 138 kV and above, subtransmission lines are 34.5 kV to 138 kV, and distribution lines are below 34.5 kV ... TDOC Time TDOC Inst Rel Inst Rel Inst Rel Inst Rel fault Increasing distance from source Increasing fault current FIGURE 3.6 Effect of instantaneous relays (From Horowitz, S.H and Phadke, A.G., ... consist of the minimum melt and total clearing curves Minimum melt is the time between initiation of a current large enough to cause the current responsive element to melt and the instant when arcing...

Ngày tải lên: 21/03/2014, 12:08

... problems include, but are not limited to, transmission line faults, the outages of lines and possible cascading that such an initial contingency may cause, outages of the generators, rapid changes of ... control: In spite of extensive simulations and studies done in the process of SPS design, it is often necessary to include the human intervention, i.e., to include human interaction in the feedback ... expensive to install and provision, but are expected to be very cost effective They have the advantage of using existing right -of- way and delivering communications directly between points of use In addition...

Ngày tải lên: 21/03/2014, 12:08

... training cases are needed to learn 63 weights In addition, some cases not used for training are needed for testing Software exists for the training process but judgment in determining the training ... equation describing the terminal voltage, v(t), the winding current, i(t), and the flux linkage L(t) is: v(tÞ À L di(t) dL(t) ¼ dt dt (5:38) where L is the leakage inductance of the winding Using trapezoidal ... occur in both numerator and denominator of Eqs (5.35) and (5.36) The denominator is not constant but varies in time with local minima at points where both the current and the derivative of the...

Ngày tải lên: 21/03/2014, 12:08

... FIGURE 6.1 OFF OFF ON LINE OFF LINE Analysis of an oscillograph record signal on line was ‘‘on’’ all during the fault to block breaker ‘‘D’’ from tripping at terminal ‘‘X’’ This would indicate ... TRIPPING OF BKR C FIGURE 6.14 Final step in sequence ß 2006 by Taylor & Francis Group, LLC INTERRUPTER BAYONET INTERRUPTER INTERRUPTER BAYONET BAYONET LINE FAULT LINE LINE BUS INTERRUPTER INTERRUPTER ... time (breaker ‘‘B’’ opens in cycles and breaker ‘‘A’’ opens in cycles) The response of the relays on line is of prime concern During the initial fault when breakers ‘‘A’’ and ‘‘B’’ are both closed,...

Ngày tải lên: 21/03/2014, 12:08

... small part of the power system Interarea modes, associated with the swinging of many machines in one part of the system against machines in other parts They are caused by two or more groups of closely ... always occur in its pure form Often, the 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 ... large interconnected systems In the 1960s, most of the power systems in the U.S and Canada were part of one of two large interconnected systems, one in the east and the other in the west In 1967,...

Ngày tải lên: 21/03/2014, 12:08

... friction, core loss, and windage in the machine Ta has the effect of accelerating the machine, which has an inertia J (kg Á m2) made up of the inertia of the generator and the prime mover and therefore ... it during deceleration The inertia of the generator The higher the inertia, the slower the rate of change of angle and the lesser the kinetic energy gained during the fault The generator internal ... point If the rotor angle increases indefinitely, the machine is said to be transiently unstable as the machine continues to accelerate and does not reach a new state of equilibrium In multimachine...

Ngày tải lên: 21/03/2014, 12:08

... analysis of system oscillations, in addition to determining the existence of problems, should be capable of identifying factors in uencing the problem and providing information useful in developing ... machines and lines of interest In other words, the swing modes of interest must be ‘‘observable’’ in the input signal selected This is mandatory for the controller to provide a stabilizing in uence ... quantifying the degree of modal interactions These indices provide information regarding the interacting modes, the states participating in these modes, and the degree of the nonlinear interaction...

Ngày tải lên: 21/03/2014, 12:08

... margin 0.4 Another family of curves similar to that of Fig 10.5 can be produced by varying the reactive power demand (or injection) at the receiving end 0.2 while maintaining the real power and ... determined based on the starting solution (point 1) and an estimate of the changes in the power flow variables (e.g., bus voltages and angles) This estimate may be computed using a linearization of ... of the power flow being nonsingular This point may be associated with a limit-induced bifurcation of a dynamic model of this ˜ system (Canizares, 2002) (A limit-induced bifurcation is defined in...

Ngày tải lên: 21/03/2014, 12:08

... domain of attraction of the postdisturbance equilibrium and determining if the initial conditions of the postdisturbance period lie within this domain of attraction or outside it The domain of ... list, the machines or group of machines at the bottom of the list are included in the group forming the rest of the system and VKEcorr is calculated In a sequential manner, machines are successively ... forming the rest of the system and VKEcorr is calculated and stored The list of VKEcorr calculated above is sorted in descending order and only those groups within 10% of the maximum VKEcorr in...

Ngày tải lên: 21/03/2014, 12:08

... maintained at the new operating point d0 (Fig 12.4) If the swing is beyond p – d0 , accelerating power or torque again becomes positive, resulting in runaway increase in angle and speed, and instability ... are of many types including Generator excitation controls Prime mover controls including fast valving Generator tripping Fast fault clearing High-speed reclosing and single-pole switching ... are interconnected over thousands of kilometers in very large power systems Thousands of generators must operate in synchronism during normal and disturbance conditions Loss of synchronism of...

Ngày tải lên: 21/03/2014, 12:08

... Hydro turbine Combustion turbine (gas turbine) Combined cycle (gas turbine and steam turbine) Wind turbine Other less common and generally smaller prime movers include geothermal steam turbine, solar ... when interarea oscillations are of interest, some form of coherent machine equivalent should be used In this case, groups of generators in the external system are combined into single lumped inertia ... energy in the rotor in MW-seconds, normalized to the MVA rating of the generator Typical values are in the range of to 15, depending on the type and size of the turbine generator If the inertia...

Ngày tải lên: 21/03/2014, 12:08

... to engineering units, includes initial corrections to known offsets in the data Automatically naming of extracted signals, includes renaming to control information concerning data sources and ownership ... important to valid planning studies Even when damping and modeling are not of immediate concern, the plants are still of special interest as sources of information and understanding about wide area ... from Internet Web sites such as ftp:= ftp.bpa.gov=pub=WAMS_Information= or from = WECC staff This and related Web sites are routinely used for off-line exchange of data, working documents, and software...

Ngày tải lên: 21/03/2014, 12:08

... margins for large systems on-line The main limitation of the approach resides in the ability of time-consuming off-line studies to accurately model system dynamics 15.10 Off-Line DSA In off-line ... marginal according to the screening process of step one In on-line studies, the time for computation is a severe constraint in addition to the challenge of interpretation and quantification of ... of the transient behavior as well as stability DSA is performed both in off-line and online environments and is computationally intensive due to the numerical integration involved in evaluating...

Ngày tải lên: 21/03/2014, 12:08

... limits, in addition to being a near perfect means of var and voltage control One transmission project, consisting of 1000 miles of 500 kV transmission lines, estimates that the application of series ... when the turbine-generator includes a hydraulic turbine In this case, the ratio of generator mass to turbine mass is relatively high, resulting in larger modal damping and modal inertia than ... of reduced levels of series compensation, operating procedures to avoid specific levels of series compensation and= or transmission line configurations, and= or relays to take the unit off-line in...

Ngày tải lên: 21/03/2014, 12:08