ac power distribution and control

... V I E W Open AccessBiology, distribution and control of Anopheles (Cellia) minimus in the context of malaria transmission in northeastern India Vas Dev1and Sylvie Manguin2* Abstract Among six ... harrisoni Harbach & Manguin (former An minimus spe-cies C) and An yaeyamaensis Somboon & Harbach (former An minimus species E), with distinct bionomical characteristics and distribution ... ecology and corridors for transmission in its earlier domains of distribution [53] (Figs 1 and 2) Bionomical characteristics Seasonal prevalence and resting habitat Anopheles minimus is characteristically

Ngày tải lên: 19/11/2022, 11:48

... direct buried low-voltage power cables 12.4 Medium- and High-Voltage Power Cables Medium- and high-voltage power cables, in addition to being insulated, are shielded to contain and evenly distribute ... because of flexibility The metal type and size determines the ampacity and losses (I2R) Copper having a higher intrinsic conductivity will have a greater ampacity and lower resistance than an equivalent ... components and function of a medium- and high-voltage cable are as follows (Figs 12.2A and 12.2B): 1 The center conductor—metallic path to carry power 2 The conductor shield—a semiconducting layer placed

Ngày tải lên: 21/03/2014, 12:11

... Current-Carrying Capacity (Ampacity) 13-513.4 Inductance and Inductive Reactance 13-6Three-Phase Transmission Lines13.5 Capacitance and Capacitive Reactance 13-14 13.6 Characteristics of Overhead ... approximated current-carrying capacity for overhead ACSR and AACs are presented in the section ‘‘Characteristics of Overhead Conductors’’ [3,9] 13.4 Inductance and Inductive Reactance A current-carrying ... config-Aluminum Strands 2 Layers, 30 Conductors Steel Strands 7 Conductors FIGURE 13.4 Stranded aluminum conductor with stranded steel core (ACSR). Trang 5voltage but are always used at 345 kV and above

Ngày tải lên: 21/03/2014, 12:11

... 795 kcmil-26=7 ACSR ‘‘Drake’’, 795 kcmil-37 strand AAC ‘‘Arbutus’’,and 795-kcmil Type 16 ‘‘Drake=SDC’’ conductors in NESC light and heavy loading areas for spans of TABLE 14.4 Sag and Tension Data ... Final sags and tensionsdepend on initial installed sags and tensions and on proper handling during installation The finalsag shape of conductors is used to select support point heights and span ... Thermal Elongation ACSR and AAC conductors elongate with increasing conductor temperature The rate of linear thermalexpansion for the composite ACSR conductor is less than that of the AAC conductor

Ngày tải lên: 21/03/2014, 12:11

... century, the linevoltage has reached the extra-high voltage (EHV) levels of 800-kV AC (Lacroix and Charbonneau, 1968)and 500-kV DC (Bateman et al., 1969) in the 1970s, and touched the ultrahigh voltage ... conductor bundles and to predict the energy lossesand environmental impact of HV lines before their installation Adequate control of line corona is obtained by controlling the surface gradient at ... avalanches accumulate in the low-field region of the gap and form ion space charges To properly interpret the development ofcorona discharges, account must be taken of the active role of these ion space

Ngày tải lên: 21/03/2014, 12:11

... impacted network. This is measured through estimates of levels of GIC flow across the network and the manifestation of impacts such as sudden and dramatic increases in reactive power demands and ... Overview of Power System Reliability and Related Space Weather Climatology 16-8 16.5 Geological Risk Factors and Geoelectric Field Response 16-9 16.6 Power Grid Design and Network Topology Risk Factors ... a simultaneous flow of GIC and undergoing half-cycle saturation, the cumulative increase in reactive power demand can be significant enough to impact voltage regulation across the network, and in extreme

Ngày tải lên: 21/03/2014, 12:11

... modules Each module consists of a capacitor (1.33 ohms), back-to-back thyristor valves controlling power flow in both directions, a reactor (0.2 ohms), and a varistor The reactors in each module, ... thyristor controlled reactor) will be zero When the load reactive power (which is usually inductive) varies, the SVC reactive power will be varied to match the load reactive power by controlling ... Reactive Power Compensation Since most loads are inductive and consume lagging reactive power, the compensation required is usually supplied by leading reactive power Shunt compensation of reactive

Ngày tải lên: 21/03/2014, 12:11

... standard ANSI=IEEE Std 644, that presents a procedure to measure electric and magnetic field emitted by power lines The conclusion is that both measuring techniques and instruments provide accurate ... conductor and the equipotential line is constant From a practical point of view, the voltage difference between a point in the space and the ground is important This voltage difference is called space ... of phases 1, 2, and 3 generated magnetic field, and Hy_1, Hy_2, Hy_3are the vertical components of phases 1, 2, and 3 generated magnetic field The vector sum of the horizontal and vertical components

Ngày tải lên: 21/03/2014, 12:11

... load components and the developed real and reactive power models as presented in these tables, the following comments on the reactive power models are important . The reactive power models vary ... per-unit real power and reactive power as a function of per-unit incremental voltage and=or incremental temperature and=or per-unit incremental torque The incremental form used and the corresponding ... incorporate only the voltage-dependent characteristic include the following . Power flow (PF) * Distribution power flow (DPF) * Harmonic power flow (HPF) * Transmission power flow (TPF) . Voltage stability

Ngày tải lên: 21/03/2014, 12:11

... Shunt Capacitor Models21.2 Analysis 21-44Power-Flow Analysis 21.1 Modeling Radial distribution feeders are characterized by having only one path for power to flow from the source(distribution ... nonequilateralconductor spacings of the three-phase overhead and underground line segments Because of the nature of the distribution system, conventional power-flow and short-circuit programsused ... spacing between conductors, the effect of the mutual couplingbetween phases is accurately taken into account The application of Carson’s equations and the phaseframe matrix leads to the most accurate

Ngày tải lên: 21/03/2014, 12:11

... Trang 122 Power System Operation and Control George L Clark Alabama Power Company Simon W Bowen Alabama Power Company 22.1 Implementation of Distribution Automation 22-1 22.2 Distribution ... electric distribution network 22.2 Distribution SCADA History SCADA is the foundation for the distribution automation system The ability to remotely monitor and control electric power system facilities ... the distribution substations and the distribution line Trang 3devices The automated distribution substations and the automated distribution line devices are then operated as a system to facilitate

Ngày tải lên: 21/03/2014, 12:11

... 67 AC power directional or AC power directional overcurrent relay is one which functions on a desired value of power flow in a given direction or on a desired value of overcurrent with AC power ... points by the appropriate factor 18 K factor for load side fuses a Two fast operations and dead time 1–2 s¼ 1.35 19 K factor for source side fuses a Two fast—Two delayed and dead time of 2 s¼ 1.7 ... features, characteristics, the conditions when the contacts operate, or are madeoperative or placed in the circuit, the following are used: TABLE 23.1 Protective Device Numbers 11 Control power transformer

Ngày tải lên: 21/03/2014, 12:11

... For instance, the arrow between Power Flow and DG Control indicates that Power Flow is used by the DG Control task That is, DG Control can run Power Flow and obtain power flow results Similarly, ... load and reactive power available from capacitors installed in Circuit j The Circuit j controller at level 2 may also know the type and operating characteristics of the DGs Therefore, Pckt-max and ... level and the circuit controls below at level 2 Each circuit might have a number of DG sites from which the circuit can import power Each such DG site has a local controller (level 1) that can handle

Ngày tải lên: 21/03/2014, 12:11

... for demand is commonly based on a customer’s maximum demand reached during the billing period One demand interval Demand FIGURE 25.2 Instantaneous power vs demand. Trang 825.4.1.2 Why is Demand ... per Hour Energy During Demand Interval Resulting Demand Trang 9measurements of Rate 1 energy (and demand) and Rate 2 energy (and demand) for the entire billing period Actual TOU service rates ... Terms 26 Basic Electric Power Utilization—Loads, Load Characterization and Load ModelingAndrew Hanson 26-1 Basic Load Characterization . Composite Loads and Composite Load Characterization . Composite

Ngày tải lên: 21/03/2014, 12:11

... Recommended Practice for Powering and Grounding Electronic Equipment IEEE Std 142–1991 IEEE Recommended Practice for Grounding Industrial and Commercial Power Systems FIPS-94 Publication Electrical Power ... to control noise on the grounding system This is ADP Units AC Units ADP Units AC Units ADP Units AC Units ADP Units AC Units 208Y/120V 480V 480V FIGURE 29.3 Separation of loads for noise control. ... following is a list of standards and recommended practice pertaining to wiring and grounding issues See the section on References for complete information National Electric Code Handbook, 1996 edition

Ngày tải lên: 21/03/2014, 12:11

... Modeling and Simulation, IEEE Press, 1998 IEEE Standard 519-1992: Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, IEEE Press, April 1993 Mohan, N., Undeland, ... documents, including both IEEE and IEC standards, recommended practices, and technical papers and reports that provide the knowledge base required to apply the standards properly Further Information ... 1Harmonics in Power Systems S.M Halpin Auburn University Power system harmonics are not a new topic, but the proliferation of high-power electronics used in motor drives and power controllers has

Ngày tải lên: 21/03/2014, 12:11

... succeeds and the packet is forwarded on every interface in OIL In our example, OIL for current multicast packet consists of interfaces S2 and E0, so the packet is forwarded on interfaces S2 and E0 ... never in the OIL; therefore, the packet is never forwarded back out of the RPF interface Copyright © 2000, Cisco Systems, Inc IP Multicast Distribution Trees and Control Protocols 2-5 Routers perform ... multicast packets were received via the interface that is on the most direct path to the source that sent the packets In the above example, each router forwards received multicast packets to each of...

Ngày tải lên: 11/12/2013, 14:15

... maintenance practices, including the training and work practices of personnel and the selection and operation of equipment 26 Power Transmission and Distribution THE PRIMARY SYSTEM The primary distribution ... real power to apparent power From Figure 1-5 Power factor = watts = cos θ EI where E = effective voltage, I = effective current, and θ is their angular displacement in phase Figure -5 Power Factor ... required capacity of facilities that would otherwise be required if based on connected loads or the sum of component load demands only Figure 1-3 Diversity Factor Load Factor Demand factors and diversity...

Ngày tải lên: 18/02/2014, 22:20

... appropriateness of the control sample below For each firm in our main and control samples we collect data on ownership and control The ownership data include the percentage of voting and cash flow (equity) ... are replaced) and of affiliation with a pyramidal business group in the main and control samples The comparison between the main sample and the control group proceeds as follows For each unifying ... this coding system, each firm can score 0, 0.5, or 1, in each year, and the maximal cumulative control change score for each firm is (representing a full control change in each year starting in...

Ngày tải lên: 07/03/2014, 01:20

... and (7) show the system can provide independent active and reactive power control by regulating the rotor current The proposed deadbeat power control, shown in Wireless Coded Deadbeat Power Control ... 3v1 L M and for the reactive power control by using (8) is: i2d (k + 1) = i2dre f = − 2Qre f L1 3v1 L M + λ1 LM (13) where: Pre f is the active power reference and Qre f is the reactive power reference ... power control, as shown in the equations (10) and (11), it is required to calculate the active and reactive power values, their errors, the stator flux magnitude and position, the slip speed and...

Ngày tải lên: 07/03/2014, 11:20