1) The document discusses power flow through transmission lines and various methods to control it, including altering voltages, lowering line impedance, and controlling the power angle.
2) Phase shift transformers are effective for controlling power angle by creating a phase shift between primary and secondary voltages, thereby regulating the direction and magnitude of power flow.
3) Direct, asymmetrical phase shift transformers control power flow by inducing a quadrature voltage through a tap, with switches determining the direction of phase shift.
HVDC (high-voltage direct current) is a highly efficient alternative for transmitting large amounts of electricity over long distances and for special purpose applications.
Applications of power electronics in HVDCKabilesh K
Role of Power electronics in HVDC and Transmission system. What are the components of Power electronics used in HVDC. Types of HVDC Links. Advantages of HVDC over HVAC.
The presentation is delivering the general aspects of transmission of electric energy. At the beginning need of transmission is presented, and then the various aspects of transmission, which affect the choice of scheme of transmission are presented. At the end of presentation, the topic is summarized as comparison among the HVAC and HVDC transmission.
This presentation was given by shivlal mohal, during the final semester of electric engineering.
HVDC (high-voltage direct current) is a highly efficient alternative for transmitting large amounts of electricity over long distances and for special purpose applications.
Applications of power electronics in HVDCKabilesh K
Role of Power electronics in HVDC and Transmission system. What are the components of Power electronics used in HVDC. Types of HVDC Links. Advantages of HVDC over HVAC.
The presentation is delivering the general aspects of transmission of electric energy. At the beginning need of transmission is presented, and then the various aspects of transmission, which affect the choice of scheme of transmission are presented. At the end of presentation, the topic is summarized as comparison among the HVAC and HVDC transmission.
This presentation was given by shivlal mohal, during the final semester of electric engineering.
Electrical Design of Overhead Lines.pptAkdDeshmukh
An a.c. transmission line has resistance, inductance and capacitance uniformly distributed along its length.
These are known as constants or parameters of the line.
The performance of a transmission line depends to a considerable extent upon these constants.
These constants determine whether the efficiency and voltage regulation of the line will be good or poor.
. R = ρl/a
ii. In a single phase or 2-wire d.c line, the total resistance (known asloop resistance) is equal to double the resistance of either conductor.
iii. In case of a 3-phase transmission line, resistance per phase is the resistance of one conductor.
High Voltage Direct Current Transmission SystemNadeem Khilji
The development of HVDC (High Voltage Direct Current) transmission system dates back to the 1930s when mercury arc rectifiers were invented. Since the 1960s, HVDC transmission system is now a mature technology and has played a vital part in both long distance transmission and in the interconnection of systems. Transmitting power at high voltage and in DC form instead of AC is a new technology proven to be economic and simple in operation which is HVDC transmission. HVDC transmission systems, when installed, often form the backbone of an electric power system. They combine high reliability with a long useful life. An HVDC link avoids some of the disadvantages and limitations of AC transmission. HVDC transmission refers to that the AC power generated at a power plant is transformed into DC power before its transmission. At the inverter (receiving side), it is then transformed back into its original AC power and then supplied to each household. Such power transmission method makes it possible to transmit electric power in an economic way.
Design of a generating substation with the description of designing a transformer. Here we show some basic components of a substation. and we also show the parameters and calculation to design a transformer of a specific ratings.
Electrical Design of Overhead Lines.pptAkdDeshmukh
An a.c. transmission line has resistance, inductance and capacitance uniformly distributed along its length.
These are known as constants or parameters of the line.
The performance of a transmission line depends to a considerable extent upon these constants.
These constants determine whether the efficiency and voltage regulation of the line will be good or poor.
. R = ρl/a
ii. In a single phase or 2-wire d.c line, the total resistance (known asloop resistance) is equal to double the resistance of either conductor.
iii. In case of a 3-phase transmission line, resistance per phase is the resistance of one conductor.
High Voltage Direct Current Transmission SystemNadeem Khilji
The development of HVDC (High Voltage Direct Current) transmission system dates back to the 1930s when mercury arc rectifiers were invented. Since the 1960s, HVDC transmission system is now a mature technology and has played a vital part in both long distance transmission and in the interconnection of systems. Transmitting power at high voltage and in DC form instead of AC is a new technology proven to be economic and simple in operation which is HVDC transmission. HVDC transmission systems, when installed, often form the backbone of an electric power system. They combine high reliability with a long useful life. An HVDC link avoids some of the disadvantages and limitations of AC transmission. HVDC transmission refers to that the AC power generated at a power plant is transformed into DC power before its transmission. At the inverter (receiving side), it is then transformed back into its original AC power and then supplied to each household. Such power transmission method makes it possible to transmit electric power in an economic way.
Design of a generating substation with the description of designing a transformer. Here we show some basic components of a substation. and we also show the parameters and calculation to design a transformer of a specific ratings.
Loadability of line is defined as the extent of load which can flow through the line without exceeding the limitations. Line Loadability is expressed in percentage of Surge Impedance Loading of line. The limiting factor for line loading are: thermal limit, voltage drop limit and steady state stability.
About Transmission Line.
Transmission Lines
Classification Of Transmission Lines
Overhead Power Line
Advantages Of Overhead Transmission Lines
Disadvantages Of Overhead Transmission Lines
Nominal “T” Method
Nominal “Pi” Model of a Medium Transmission Line
Underground Transmission Lines
Classification Of Underground Cables
Advantages Of Underground Cables
Disadvantages Of Underground Cables
Alternating current (AC) is the main driving force in the industries and residential areas, but for the long transmission line (more than 650 KM) AC transmission is more expensive than that of direct current (DC). Technically, AC transmission line control is more complicated because of the frequency. DC transmission does not have these limitations, which has led to build long HVDC transmission lines over the last 40 years. HVDC technology made possible to transfer bulk power over long distances.
A cylindrical capacitor is a specific type of capacitor characterized by its cylindrical structure. It consists of two coaxial (aligned along the same axis) cylinders or conductors, one inside the other, separated by a dielectric material.
Here are the key components and characteristics of a cylindrical capacitor:
1. **Structure**: It comprises an inner cylinder and an outer cylinder, both arranged along the same axis. The space between these cylinders is filled with a dielectric material that prevents direct electrical contact between the cylinders.
2. **Dielectric Medium**: The dielectric material, which could be air, vacuum, or other non-conductive substances, helps in maintaining a potential difference between the cylinders without allowing the flow of current between them.
3. **Capacitance Factors**: The capacitance of a cylindrical capacitor is influenced by several factors, including the radii of the cylinders, their lengths, and the properties of the dielectric material between them. Formulas exist to calculate the capacitance based on these parameters.
4. **Applications**: Cylindrical capacitors find applications in various fields such as electronics, power systems, and telecommunications due to their relatively high capacitance compared to other capacitor designs. They are utilized where efficient energy storage in a compact form is required.
5. **Energy Storage**: During charging, energy from an external source is expended to charge the capacitor. This energy gets stored within the electrostatic field formed in the dielectric material. Upon discharge, this stored energy is released.
6. **Functions**: Cylindrical capacitors serve multiple functions, including energy storage, signal processing in circuits, filtering, and regulation of electrical energy in power transmission systems.
In summary, cylindrical capacitors are a specific design of capacitors consisting of coaxial cylinders separated by a dielectric medium. Their structure and properties make them valuable in various technological applications where efficient energy storage and manipulation of electrical signals are required.
An A.C. device used to change high voltage low current A.C. into low voltage high current A.C. and vice-versa without changing the frequency
In brief,
1. Transfers electric power from one circuit to another
2. It does so without a change of frequency
3. It accomplishes this by electromagnetic induction
4. Where the two electric circuits are in mutual inductive influence of each other.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
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Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
2. We will be seeing…
Introduction.
Power Carrying Conductors
Power flow through transmission line.
Single - line diagram of three phase transmission.
Derivation.
Circle diagram
Analytical method.
Graphical method.
Summary.
3
3. Introduction
The electric power generated in the generating station is transmitted using
transmission lines.
Transmission lines are conductors designed to carry electricity over a long
distances with minimum losses and distortion.
The parameters associated with these transmission lines are inductance,
capacitance, resistance .
4
4. Physical Characteristics – underground cables
• Cable lines are designed to be placed underground or under
water. The conductors are insulated from one another and
surrounded by protective sheath.
• Cable lines are more expensive and harder to maintain.
They also have capacitance problem – not suitable for long
distance.
5. High Voltage Power Lines (overhead)
• Common voltages in india: 132, 220, 400, 765, 1100 kV
• Bundled conductors are used in extra-high voltage lines
• Stranded instead of solid conductors are used.
6. HVDC Transmission
• Because of the large fixed cost
necessary to convert ac to dc and
then back to ac, dc transmission is
only practical in specialized
applications
– long distance overhead power
transfer (> 400 miles)
– long underwater cable power
transfer
– providing an asynchronous means
of joining different power systems.
7. Electrical Characteristics
• Transmission lines are characterized by a series resistance,
inductance, and shunt capacitance per unit length.
• These values determine the power-carrying capacity of the
transmission line and the voltage drop across it at full load.
• The DC resistance of a conductor is expressed in terms of
resistively, length and cross sectional area as follows:
8. Cable resistance
• The resistively increases linearly with temperature over normal
range of temperatures.
• If the resistively at one temperature and material temperature
constant are known, the resistively at another temperature can
be found by
9. Cable Resistance
• AC resistance of a conductor is always higher
than its DC resistance due to the skin effect
forcing more current flow near the outer
surface of the conductor. The higher the
frequency of current, the more noticeable skin
effect would be.
• Wire manufacturers usually supply tables of
resistance per unit length at common
frequencies (50 and 60 Hz). Therefore, the
resistance can be determined from such
tables.
10. ACSR Conductor Table Data
Inductive and Capacitive
Reactance for 1-foot Spacing
Geometric Mean Radius
12. Remarks on line inductance
• The greater the spacing between the phases of a
transmission line, the greater the inductance of the line.
– Since the phases of a high-voltage overhead transmission line must be
spaced further apart to ensure proper insulation, a high-voltage line will
have a higher inductance than a low-voltage line.
– Since the spacing between lines in buried cables is very small, series
inductance of cables is much smaller than the inductance of overhead lines
• The greater the radius of the conductors in a transmission
line, the lower the inductance of the line. In practical
transmission lines, instead of using heavy and inflexible conductors of
large radii, two and more conductors are bundled together to
approximate a large diameter conductor, and reduce corona loss.
GMR2 GMR.d
4
GMR 1.09 4
GMR.d3
3
GMR 3
GMR.d 2
14. Shunt capacitance
V
• The capacitance of a single-phase transmission line is given by
(see derivation in the book): (ε = 8.85 x 10-12 F/m)
• Since a voltage V is applied to a pair of conductors separated by
a dielectric (air), charges q of equal magnitude but opposite
sign will accumulate on the conductors. Capacitance C between
the two conductors is defined by
C
q
16. Remarks on line capacitance
1. The greater the spacing between the phases of a
transmission line, the lower the capacitance of the line.
– Since the phases of a high-voltage overhead transmission line
must be spaced further apart to ensure proper insulation, a high-
voltage line will have a lower capacitance than a low-voltage line.
– Since the spacing between lines in buried cables is very small,
shunt capacitance of cables is much larger than the capacitance
of overhead lines.
2. The greater the radius of the conductors in a transmission
line, the higher the capacitance of the line. Therefore,
bundling increases the capacitance.
17. Power flow
transmission line
through
G
Generating
station
SS =PS +
VS ∠ δ VR ∠ 0
Transmission
jQS line
SR =PR + jQR
LOA
D
ABCD
Bus-1 Bus-2
Fig:- Single line diagram of three phase
transmission
Assuming,
VR = Receiving End voltage
= |VR| ∠ 0°(VR is reference phasor)
VS = |VS| ∠ δ°= Sending End voltage(δ is the phase angle between sending and
receiving end voltage)
5
18. Short line model
• Overhead transmission lines shorter than 50 miles can be
modeled as a series resistance and inductance, since the
shunt capacitance can be neglected over short distances.
• The total series resistance and series reactance can be
calculated as
• where r, x are resistance and reactance per unit length and d
is the length of the transmission line.
19. Short line model
• Two-port network model:
• The equation is similar to that of a synchronous generator and
transformer (w/o shunt impedance)
20. Short line
Voltage Regulation:
1. If lagging (inductive) loads are added at the end of a
line, the voltage at the end of the transmission line
decreases significantly – large positive VR.
2. If unity-PF (resistive) loads are added at the end of a
line, the voltage at the end of the transmission line
decreases slightly – small positive VR.
3. If leading (capacitive) loads are added at the end of a
line, the voltage at the end of the transmission line
increases – negative VR.
21. Short line – simplified
• If the resistance of the line is ignored, then
• Therefore, the power flow through a transmission line depends on
the angle between the input and output voltages.
• Maximum power flow occurs when δ = 90o.
• Notes:
– The maximum power handling capability of a transmission line is a
function of the square of its voltage.
– The maximum power handling capability of a transmission line is
inversely proportional to its series reactance (some very long lines
include series capacitors to reduce the total series reactance).
– The angle δ controls the power flow through the line. Hence, it is
possible to control power flow by placing a phase-shifting transformer.
22. Line Characteristics
• To prevents excessive voltage variations in a power system, the
ratio of the magnitude of the receiving end voltage to the
magnitude of the ending end voltage is generally within
0.95 ≤ VS/VR ≤ 1.05
• The angle δ in a transmission line should typically be ≤ 30o to
ensure that the power flow in the transmission line is well below
the static stability limit.
• Any of these limits can be more or less important in different
circumstances.
– In short lines, where series reactance X is relatively small, the
resistive heating usually limits the power that the line can supply.
– In longer lines operating at lagging power factors, the voltage drop
across the line is usually the limiting factor.
– In longer lines operating at leading power factors, the maximum
angle δ can be the limiting f actor.
23. Example
• A line with reactance X and negligible resistance supplies a
pure resistive load from a fixed source VS. Determine the
maximum power transfer, and the load voltage VR at which
this occurs. (Hint: recall the maximum power transfer theorem
from your basic circuits course)
24.
25.
26.
27. Medium Line (50-150 mi)
• the shunt admittance must be included in calculations. However, the
total admittance is usually modeled (π model) as two capacitors of
equal values (each corresponding to a half of total admittance)
placed at the sending and receiving ends.
• The total series resistance and series reactance are calculated as
before. Similarly, the total shunt admittance is given by
• where y is the shunt admittance per unit length and d is the length
of the transmission line.
29. Long Lines ( > 150 mi)
• For long lines, both the shunt capacitance and the series
impedance must be treated as distributed quantities. The
voltages and currents on the line are found by solving differential
equations of the line.
• However, it is possible to model a long transmission line as a π
model with a modified series impedance Z’ and a modified shunt
admittance Y’ and to perform calculations on that model using
ABCD constants. These modified values are
where the propagation constant is defined by
30. Surge Impedance Loading
impedance:
• The surge impedance of a line is defined as
ZC z / y L/C
• Surge Impedance Loading (SIL) is the power delivered by a
line to a pure resistive load that is equal to its surge
V 2
V 2
SIL 3
L
MW
L /C L /C
• Under such loading, the line consumes as much reactive
power as it generates and the terminal voltages are equal
to each other.
• Power system engineers sometime find it convenient to
express the power transmitted by a line in terms of per-
unit of SIL.
31. Reactive Power Generation/Consumption
Note that a transmission line both absorbs and generates
reactive power:
• Under light load, the line generates more reactive
power than it consumes.
• Under “surge impedance loading”, the line generates
and consumes the same amount of reactive power.
• Under heavy load, the line absorbs more reactive
power than it generates.
33. Power Flow Through a Transmission Line
• Let
• Then the complex power at the receiving end is given by
A A, B B ,V V ,V V 0o
S S R R
2
P jQ
B
B
V V A V
V I*
S R
( ) R
( )
R R
R
R
Now, we separate real and imaginary parts, then we get the values of PR and
QR So, Receiving end True power,
P = |Vs||VR| cos (β −δ ) - |A||VR
2| cos(β −α)
Receiving end Reactive power,
Q = |Vs||VR| sin (β −δ ) - |A||VR
2| sin(β −α)
34. Methods Of Finding The Performance Of Transmission
Line.
11
Basically two methods
Analytical method.
Graphical method.
Analytical methods are found to be laborious, while graphical method is
convenient.
Graphical method or circle diagram are helpful for determination of active
power P, Reactive power Q, power angle δ and power factor for given load
condition.
Relations between the sending end and receiving end voltage and currents
are given below.
VS = AVR + BIR A, B, C, D are generalised constants of transmission.
IS = CVR + DIR VS = sending end voltage,
37. We have seen…
21
Receiving end True power,
R |B| |B|
P = |Vs||VR| cos (β −δ ) - |A||VR2| cos(β −α)
Receiving end Reactive power,
R |B| |B|
Q = |Vs||VR| sin (β −δ ) - |A||VR | sin(β −α)
2
PR(max) = R
2|
|Vs||VR| |A||V
|B| |B|
- cos(β −α)
|A||V 2|
|B|
QR(max) = - R sin(β −α)
Construction of circle diagram
Receiving End Power Circle Diagram
Sending End Power Circle Diagram :
38. Where, VS is sending end voltage
. VR is receiving end voltage
. XL is line impedance
. δ is power angle (angle between sending end and receiving end voltages)
As observed from the above formulae, active power transmitted can be
controlled by
. (i) Altering sending/receiving end voltage(s)
. (ii) Lowering line impedance
. (iii) By controlling power angle
Altering sending/receiving end voltage
Active power flow on transmission lines can be controlled either by altering
sending end voltage or receiving end voltage. But, whenever voltages are
altered for controlling active power, it has a bigger impact on reactive power
component. Hence, this method is not effective.
Lowering line impedance
Total line reactance can be lowered by placing series capacitor to
compensate line inductance. This increases not only active but also reactive
power flow. Hence, this method is also not effective.
Controlling power angle
By altering the power angle, active power can be increased with decrease in
reactive power and vice versa as per above formulae.
39. Phase Shift Transformers (PSTs) are the best option to control power
angle……
* A phase shift transformers (PST) can be employed for power control on
transmission lines by altering power angle.
* These are special transformers used to create a phase shift between the
primary side and secondary side voltages.
* Both magnitude and direction of power flow can be controlled by varying
the phase shift.
Types of PSTs
. i) Direct PSTs
. ii) Indirect PSTs
. iii) Symmetrical PSTs
. iv) Asymmetrical PSTs
Direct PSTs
The phase is obtained by connecting the windings in an appropriate manner.
Indirect PSTs
Connections are based on two separate transformers; one variable tap
exciter to regulate the amplitude of the quadrature voltage and one series
transformer to inject the quadrature voltage in the right direction.
Symmetrical PSTs
Creates an output voltage with an altered phase angle compared to the input
voltage, but with same amplitude.
Asymmetrical PSTs
Creates an output voltage with an altered phase angle and amplitude
compared to the input voltage.
40. Lets us consider direct, asymmetrical PST (as follows)…
Direct, Asymmetrical PSTs
The following is the configuration of the direct type asymmetrical PST.
The tap controls angle between sending end voltage and receiving end
voltages by inducing a quadrature voltage. The direction of the phase shift
can be controlled by switches.
41.
42. Long line series and shunt compensation
• Shunt reactors are used to compensate the line shunt
capacitance under light load or no load to regulate voltage.
• Series capacitors are often used to compensate the line
inductive reactance in order to transfer more power.