electric power generation, transmission, and distribution ( (6)

... integrals (assuming t is small)ðt2t1v(t)dt ¼ Rðt2t1i(t)dt þ L(i(t2) À i(t1)) (5 :33)ðt2t1v(t)dt ¼ Rðt2t1i(t)dt þ L(i(t2) À i(t1)) (5 :34)R and L are given byR ¼(vkþ1þ ... for the integral in Eq. (5 .38)ðt2t1v(t)dt À L[i(t2) À i(t1)] ¼ L(t2) À L(t1 )(5 :39)givesL(t2) À L(t1) ¼T2[v(t2) þ v(t1)] ÀL[i(t2) À i(t1)] (5 :40)orLkþ1¼ LkþT2[vkþ1þ ... signals sk.S ¼s1(T) s2(T) ÁÁÁ sK(T)s1 (2 T) s2 (2 T) ÁÁÁ sK (2 T).........s1(NT) s2(NT) ÁÁÁ sK(NT)2666437775 (5 :24)The presence of the error e and the fact that...

electric power generation, transmission, and distribution ( (2)

... Anti-MotoringProtection (3 2) . Overexcitation Protection (2 4) . Overvoltage (5 9) . VoltageImbalance Protection (6 0) . System Backup Protection (5 1V and 21) .Out-of-Step Protection . Abnormal ... during peak and emergency conditions, performing coordination studies that include source and low side protectionequipment, and expected transformer size and winding conﬁguration (ANSI=IEEE, ... maintenance and cost advantages found with power fuses.Protection and control devices, circuit breakers, and station batteries are required. The overcurrentrelays are a small part of the total cost and...

electric power generation, transmission, and distribution ( (3)

... Anti-Motoring Protection (3 2) 2-82.8 Overexcitation Protection (2 4) 2-92.9 Overvoltage (5 9) 2-102.10 Voltage Imbalance Protection (6 0) 2-102.11 System Backup Protection (5 1V and 21) 2-122.12 Out-of-Step ... (1 ) the real power is below a negative pre-setthreshold SET_1, (2 ) the steam valve or a differential pressure switch is closed (either conditionindicating the removal of the prime-mover), (3 ) ... generation and load on an electrical network, the networkfrequency will be stable and the internal angle of the generators will remain constant with respect toeach other. If an imbalance (loss of generation,...

electric power generation, transmission, and distribution ( (4)

... zonebusClosed zonegeneratorleadTransf.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, ... time and the tripping logic of both the primary and its duplicate system are the same.It is not always practical to duplicate every element of the protection chain. On High Voltage (HV) and EHV ... those lines operating at 138 kV and above, sub-transmission lines are 34.5 kV to 138 kV, and distribution lines are below 34.5 kV. These are not rigiddeﬁnitions and are only used to generically...

electric power generation, transmission, and distribution ( (5)

... and areavailable under two similar standards: (a) Sonet (synchronous optical networks) is the American Systemunder ANSI T1.105 and Bellcore GR standards; (b) synchronous digital hierarchy (SDH) ... projection onto the PQ plane (a bold curve). It can beobserved that: (a) there may be many possible trajectories to (and points of) voltage collapse; (b) active and reactive power margins depend on ... development.PQVTrajectory (P,Q,V )Point of voltagecollapseAn operating pointActive power marginReactive power marginFIGURE 4.2 Relationship between voltages, active and reactive powers of the load and voltage...

electric power generation, transmission, and distribution ( (7)

... good ( ‘A’’)block signal and questionable ( ‘B’’) block signal. The good block signal is shown as one that blocks(comes ‘‘on’’) within a fraction of a cycle after the fault is detected and unblocks ... classifying operations as good (A)or questionable (B) as shown in Fig. 6.2. The ﬁrst fault current waveform (upper left) is classiﬁed as Abecause it is sinusoidal in nature and cleared in 3 cycles. ... 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). InFig. 6.15 the...

electric power generation, transmission, and distribution ( (8)

... Design and OperationFor reliable service, a power system must remain intact and be capable of withstanding a wide variety ofdisturbances. Owing to economic and technical limitations, no power ... studies. Powerful analyt icaltools are available for its analysis (Van Cutsem et al., 1995; Gao et al., 1992; Morison et al., 1993), and well-established criteria and study procedures are evolving (Abed, ... application of power electronic based controllers referred to as FACTS(Flexible AC Transmission Systems) controllers for damping of power system oscillations (IEEE, 1996).In the 1970s and 1980s,...

electric power generation, transmission, and distribution ( (9)

... given by Eq. (8 .7) and interchanging per unit power for torqued2 ddt2 ¼v02H ( Pm À Pe )(8 :10)Multiplying both sides by 2d=d t and integrating givesd ddt2¼ðdd0v0 ( Pm À ... relationship and describes thetransmitted power as a function of rotor angle. It is clear from Eq. (8 .9) that the maximum power is afunction of the voltages of the generator and inﬁnite bus, and more ... to answer in this section.Two concepts are essential in understanding transient stability: (i) the swing equation and (ii) the power angle relationship. These can be used together to describe...

electric power generation, transmission, and distribution ( (10)

... the form eljt and e(lkþll)t:xi(t) ¼Xnj¼1uijzj0eljtþXnj¼1uijXnk¼1Xnl¼1Cjkllkþ llÀ ljzk0zl0e(lkþll)t"# (9 :2)lk, ll, and ljare the ... J., and Fortin, S., A minimal realization approach to reduced-ordermodeling and modal analysis for power system response signals, IEEE Trans. Power Systems, 8(3 ),1020–1029, 1993.Kundur, P., Power ... IEEETrans. Power Systems, 5(4 ), 1455–1469, November 1990.Martins, N. and Quintao, P.E.M., Computing dominant poles of power system multivariable transferfunctions, IEEE Trans. Power Systems, 1 8(1 ),...

electric power generation, transmission, and distribution ( (11)

... steady-state (e ¼ 0) is reached. Analytical expressions of the loadmodel, including real (P) and reactive (Q) power dynamics, areTpdxdt¼ Ps(V ) À P, P ¼ xPt(V )Tqdydt¼ Qs(V ) À Q, ... The equations for thesimulation areTqd yd t¼ Qs(V) ¼ Q(t); Q(t) ¼ yQt ( V)Q( t) ¼ Network(Vs t)where the function Network(Vst) consists of three polynomials each representing ... the reader and are thoroughly described by Mansour (1 993), Lof et al. (1 992, 1993), Gao et al. (1 992), and Can˜izares (2 002).10.2 Analytical FrameworkThe slow nature of the network and load...

Xem thêm