combined heat and power generation eurostat

Ngày tải lên: 05/09/2013, 14:59

Ngày tải lên: 22/06/2014, 19:20

... and larger wind farms. In addition, a comparative cost and power study should be performed to determine the relative economics of HAWT and VAWT wind farms. International Journal of Energy and ... that a uniform grid arrangement is also best in the case of a VAWT for optimal power generation. 2. Wake, power and cost modeling of a HAWT 2.1 Jensen's wake modeling of a HAWT All the ... simple wake model of Jensen [4] and use a genetic algorithm for optimization of an objective function based on power output or a combination of power output and cost [1-3]. In Jensen’s model,...

Ngày tải lên: 05/09/2013, 17:03

... 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 ... underestimate the heating effect. Bear in mind that ‘‘true-rms’’ is only as good as the pass-band of the antialiasing filters and sampling rate, for numerical relays. A second effect is heating due...

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, ... 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 ... a small set-value SET_4 and the negative and zero sequence currents I2 and I2 do not exceed a small set-value SET_3, then a fuse failure condition will pick up to one and remain in that state...

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 ... a multiphase fault between phases x and y, Ex À Ey Ix À Iy ¼ Z 1 (3:1) where x and y can be a, b, or c and Z 1 is the positive sequence impedance between the relay location and the fault. For ground distance ... they provide both phase and ground protection. A basic complement of relays would be two phase and one ground relay. This arrangement will protect the line for all combinations of phase and ground faults...

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 ... 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 ... voltage collapse An operating point Active power margin Reactive power mar g in FIGURE 4.2 Relationship between voltages, active and reactive powers of the load and voltage collapse. ß 2006 by Taylor...

Ngày tải lên: 21/03/2014, 12:08

... 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 w k and v k and with a known mean and covariance ... time and Eq. (5.44) represents the measurements. The terms w k and v k are discrete time random processes representing state noise, i.e., random inputs in the evolution of the parameters, and ... 1972. Girgis, A.A. and Brown, R.G., Application of Kalman filtering in computer relaying, IEEE Trans. on Power Appar. and Syst., 100, 3387, July 1981. Harder, E.L. and Marter, W.E., Principles and practices...

Ngày tải lên: 21/03/2014, 12:08

... ‘‘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. ... 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...

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 ... G.K., Gao, B., and Kundur, P., Voltage stability analysis using static and dynamic approaches, IEEE Trans. on Power Systems, 8, 3, 1159, 1993. Morison, G.K., Wang, L., and Kundur, P., Power System ... faults, loss of generation, or circuit contingencies. This ability is determined by the system-load characteristics and the interactions of both continuous and discrete controls and protections....

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 P m1 , the electrical output power is P e (equal to P m ) and the corresponding rotor angle is d a . As the mechanical power ... LLC. 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 the system and therefore cannot be eliminated. However, their damping and frequency can be modified. . As power systems evolve, the frequency and damping of existing modes change and new modes ... 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...

Ngày tải lên: 21/03/2014, 12:08

... Van Cutsem, T., and Vittal, V., Definition and classification of power system stability, IEEE Transac- tions on Power Systems, 19, 1387–1401, 2004. Lof, P A., Smed, T., Andersson, G., and Hill, D.J., ... these Jacobians, and their sensitivities with respect to various system parameters. . Bus voltage profiles and their sensitivity to variations in active and reactive power of the load and generators, ... reactive 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...

Ngày tải lên: 21/03/2014, 12:08

... Electr. Power and Energy Syst., 11, 1, 47–56, Jan. 1989. Padiyar, K.R., and Sastry, H.S.Y., Topological energy function analysis of stability of power systems, Int. J. of Electr. Power and Energy ... equilibrium and stability in power systems, IEEE Trans. Power Appar. Syst., PAS-72, 1127–1130, May=June. Tavora, Carlos J., and Smith, O.J. M., Equilibrium analysis of power systems, IEEE Trans. Power ... scale electric power systems—a survey, Automatica, 21, 1, 1–21, 1985. Sauer, P.W., and M.A. Pai, Power System Dynamics and Stability, Prentice Hall, New York, 1998. Tavora, Carlos J., and Smith,...

Ngày tải lên: 21/03/2014, 12:08

... 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 ... C.W., Nassief, F.R., and Cresap, R.L., Northwest power pool transient stability and load shedding controls for generation load imbalances, IEEE Transactions on Power Apparatus and Systems, PAS-100(7), ... electric power and torque to be zero, with accelerating torque equal to T m . (Although generator current is very high for the short circuit, the power factor, and active current and active power...

Ngày tải lên: 21/03/2014, 12:08

... for Power) , 105(1), October 1983, 865–869. Standard load models for power flow and dynamic performance simulation, IEEE Transactions, PWRS- 10, August 1995, Static Var compensator models for power ... this equivalent circuit, r a and L l represent the resistance and leakage inductance of the generator stator, L ad and L aq represent the mutual inductance between stator and rotor, and the remaining elements ... (OEL) Voltage sensing and compensation Underexcitation limiter (UEL) Generator flux (Volts/Hertz) limiter Power, frequency, or other signals Power system stabilizer Rotor speed Tacho- meter Power transformer Terminal voltage and...

Ngày tải lên: 21/03/2014, 12:08

... 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 ... mandates issued by NERC and at various levels of government [23]. It is likely that an infrastructure for developing and exchanging dynamic information wi ll be found necessar y for assuring power ... thousand derived signals that are v iewed in real time, or during off-line analysis of power system performance. Data sources are of many kinds, and they may be located anywhere in the power...

Ngày tải lên: 21/03/2014, 12:08

Ngày tải lên: 21/03/2014, 12:08

Ngày tải lên: 21/03/2014, 12:08

Ngày tải lên: 21/03/2014, 12:08