TRANSMISSION LINES DESIGN and ELECTRICAL ENGINEERING HUB

Review 'A highly readable and valuable source book on BIPV for a wide audience' Dr Clive Weatherby, Head of Technology, Solar Century --This text refers to an alternate Hardcover edition. Product Description Designing with Solar Power is the reult of international collaborative research and development work carried out within the remit of the International Energy Agency's Photovoltaic Power Systems Programme (IEA PVPS), where world-wide and interdisciplinary expert experience on building-integrated photovoltaics has been brought together to provide state-of-the-art information on technology and design issues.  This book's mission is to inspire building professionals to think about photovoltics as an energy-producing building material, and to incorporate this energy source whenever possible. Hundreds of photos, diagrams and charts demonstrate the fundamentals of photovoltaics, the hurdles to be faced, experience to date, and overall, its enormous potent...

Electric power systems as we know them began developing in the early 20th century. Initially, generating plants were associated only with local loads that typically consisted of lighting and electric transportation. If anything in the system failed — generating plant, power lines, or connections — the lights would quite literally be “out.” Customers had not yet learned to depend on electricity being nearly 100% reliable, so outages, whether routine or emergency, were taken as a matter of course. As reliance on electric power grew, so did the need to find ways to improve reliability. Generating stations and power lines were interconnected to provide redundancy, and higher voltages were used for longer distance transportation of electricity. Points where power lines came together or where voltages were transformed came to be known as “substations.” Substations often employed protective devices to allow system failures to be isolated so that faults would not bring down the en...

Dead Tank Circuit Breakers Circuit breakers are available as live-tank or dead-tank designs. Dead-tank designs put the interrupter in a grounded metal enclosure. Interrupter maintenance is at ground level and seismic withstand is improved vs. the live-tank designs. Bushings are used for line and load connections which permit installation of bushing current transformers for relaying and metering at a nominal cost. The dead-tank breaker does require additional insulating oil or gas to provide the insulation between the interrupter and the grounded tank enclosure. Live Tank Circuit Breakers Live-tank circuit breakers consist of an interrupter chamber that is mounted on insulators and is at line potential. This approach allows a modular design as interrupters can be connected in series to operate at higher voltage levels. Operation of the contacts is usually through an insulated operating rod or rotation of a porcelain insulator assembly by an operator at ground level....

The substation grounding system is an essential part of the overall electrical system. The proper grounding of a substation is important for the following two reasons: 1. It provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment 2. It provides a safe environment to protect personnel in the vicinity of grounded facilities from the dangers of electric shock under fault conditions The grounding system includes all of the interconnected grounding facilities in the substation area, including the ground grid, overhead ground wires, neutral conductors, underground cables, foundations, deep well, etc. The ground grid consists of horizontal interconnected bare conductors (mat) and ground rods. The design of the ground grid to control voltage levels to safe values should consider the total grounding system to provide a safe system at an economical cost. The following information is mainly concerned with personnel saf...

A circuit breaker is defined as “a mechanical switching device capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying and breaking for a specified time, and breaking currents under specified abnormal circuit conditions such as a short circuit” (IEEE Std. C37.100-1992). Circuit breakers are generally classified according to the interrupting medium used to cool and elongate the electrical arc permitting interruption. The types are: • Air magnetic • Oil • Air blast • Vacuum • SF6 gas Air magnetic circuit breakers are limited to older switchgear and have generally been replaced by vacuum or SF6 for switchgear applications. Vacuum is used for switchgear applications and some outdoor breakers, generally 38 kV class and below. Air blast breakers, used for high voltages ( ≥ 765 kV), are no longer manufactured and have been replaced by breakers using SF6 technology. Oil circuit breakers have been widely used in the u...

There are six types of substation bus/switching arrangements commonly used in air insulated substations: 1. Single bus 2. Double bus, double breaker 3. Main and transfer (inspection) bus 4. Double bus, single breaker 5. Ring bus 6. Breaker and a half Single Bus -One main bus with all circuits connected directly to the bus. -Very low reliability. -A single failure to the main bus or any circuit section between its circuit breaker and the main bus will cause an outage of the entire system. -Maintenance of the bus would require the outage of the total system, use of standby generation, or switching to adjacent station, if available. Since the single bus arrangement is low in reliability, it is not recommended for heavily loaded substations or substations having a high availability requirement. Reliability of this arrangement can be improved by the addition of a bus tiebreaker to minimize the effect of a main bus failure. Double Bus, Double Breaker ...

The substation circuit-breaker tripping power may be from either a d-c or an a-c source. A d-c tripping source is usually obtained from a tripping batttery, but may also be obtained from a station service battery or a charged capacitor. The a-c tripping source is obtained from current transformers located in the circuit to be protected. DC Battery Trip When properly and adequately maintained, the battery offers the most reliable tripping source. It requires no auxiliary tripping devices, and uses single-contact relays that directly energize a single trip coil in the breaker. A battery trip supply is not affected by the power-circuit voltage and current conditions during time of faults, and therefore is considered the best source for all types of protective relay tripping. An additional advantage is that only one battery is required for each substation location and it may be used for other equipment; e.g., highvoltage breaker trip circuits and ground switches. A trippi...

Fuse Power fuses have been used for many years to provide transformer fault protection. Generally it is recommended that transformers sized larger than 10 MVA be protected with more sensitive devices such as the differential relay discussed later in this section. Fuses provide a low maintenance, economical solution for protection. Protection and control devices, circuit breakers, and station batteries are not required. There are some drawbacks. Fuses provide limited protection for some internal transformer faults. A fuse is also a single phase device. Certain system faults may only operate one fuse. This will result in single phase service to connected three phase customers. Fuse selection criteria include: adequate interrupting capability, calculating 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 (ANSI=IEEE, 1985). Overc...

A great book for beginners and expert alike. Electricity and Electronic fundamentals is a must in your collection of E-Books on the said topic of Electrical and Electronics Engineering. An introductory text, Electricity and Electronics Fundamentals, delineates key concepts in electricity using a simplified approach that enhances learning. Mathematical calculations are kept to the very minimum and concepts are demonstrated through application examples and illustrations.  The books span of topics includes vital information on direct current electronics, alternating current electricity and semiconductor devices as well as electronic circuits, digital electronics, computers and microprocessors, electronic communications, and electronic power control.  Supplementary appendices provide a glossary and section on electrical safety along with an explanation of soldering techniques.  DOWNLOAD LINK 1 DOWNLOAD LINK 2

Eddy currents also known as called Foucault currents are induced currents present in a conductors, wherein its direction is in opposition with the change in flux that generated them. When a conductor is exposed to a magnetic field that is dynamic (changing due to relative motion), Eddy currents will be present, as circulating flow of electrons, or a current, within the body of the conductor.  These circulating eddies of current create induced magnetic fields that oppose the change of the original magnetic field due to Lenz's law, causing repulsive or drag forces between the conductor and the magnet.  When a conductor moves relative to the field generated by a source, electromotive forces (EMFs) can be generated around loops within the conductor. These EMFs acting on the resistivity of the material generate a current around the loop, in accordance with Faraday's law of induction. These currents dissipate energy, and create a magnetic field that tends to oppose th...

General outline of the insulation coordination procedure: The procedure for insulation coordination consists of a) Determination of voltage stresses b) Selection of the insulation strength to achieve the desired probability of failure The voltage stresses can be reduced by the application of surge-protective devices, switching device insertion resistors and controlled closing, shield wires, improved grounding, etc. System transient analyses that include the selection and location of the overvoltage limiting devices are performed to determine the amplitude, waveshape, and duration of system voltage stresses. The overvoltage stress may be characterized either by — The maximum crest values, or — A statistical distribution of crest values, or — A statistical overvoltage value [this is an overvoltage generated by a specific event on the system (lightning discharge, line energization, reclosing, etc.), with a crest value that has a 2% probability of being exceede...

For purposes of practical arrester application, switching surge voltages can be classiÞed according to required arrester reseal voltage capability, which depends upon the number and severity of possible surge currents discharged by the arrester and the duration of ensuing temporary overvoltages. - Transients Where Several Sparkovers Are Permitted These transients are usually initiated by inherent switch action and stress the surge arrester through multiple operations. The transients are repetitive in nature and may be of sufÞcient magnitude to produce sparkover many times. The severe duty on the arrester results from the repeated follow current rather than from the energy in the surge. Heating of the gap and valve block assemblies can be excessive and hence cause arrester failure. Satisfactory performance of the surge arrester under these conditions is dominated by the capability of the switching device. Arrester problems are best avoided through the use of switching dev...

De-energizing motors can produce surges that may adversely affect motors under certain conditions, much as when the motor is de-energized before it has come up to speed (aborted starts) or when a vacuum breaker is used to do the switching. When air-magnetic switchgear is used to de-energize a motor that is running under normal operating conditions, no significant surges are produced. This is true because the back emf of the motor after it is disconnected does not immediately go out of-phase with the source side voltage. Therefore, the recovery voltage across the breaker is not severe and restrikes do not usually occur. However, when a breaker is tripped before the motor comes up to speed, the back emf is low and the recovery voltage can be severe. Thus, restrikes are likely to occur causing severe surges. These surges can have magnitudes above 2.7 pu with front times of 1 μs or less. When vacuum breakers are used to switch motors, several problems can occur such as current ...

If one or more of the following surge protective elements exist for a particular motor application, the need for additional surge protection may not be necessary. Some of these listed elements will be effective for reducing stress on the groundwall insulation and some will be effective for protecting the turn insulation. Some of the elements will be effective for motor starting surges while others will be effective in limiting stress from lightning surges and system switching surges. For a particular machine installation a quantitative evaluation such as is presented in this guide is required to determine whether protective coordination with the insulation withstand is achieved. a) Effective shielding from lightning strokes to overhead lines supplying the building or plant can reduce the probability of a lightning surge overstress. b) Gapless metal-oxide surge arresters at the motor terminals can limit the magnitude of voltage stress without creating a steep-front as cau...

Electrostatic Voltmeter or sometimes called Surface DC Voltmeter are instruments that measure voltage even without the actual transfer of electric charge. These devices can measure voltages through close proximities of the probe, to the measured quantities. This device is an answer to the uncertainty principle problem of measuring data. When measuring voltage distribution on a dielectric surface, any measurement technique that requires charge transfer, no matter how small, will modify or destroy the actual data. Thus Electrostatic Voltmeters may come in handy. Below are links on the topic Electrostatic Voltmeters to help you understand more on the topic. Using Electrostatic Voltmeters Static problems are challenging to solve because static dissipaters, such as ionizing strings or static bars, should be located to treat the side of the film with static. An electrostatic voltmeter provides detailed information on the location, the amount, and the polarity of stat...

Reviews it is the most comprehensive electric motor handbook available currently, extensively covering all types of motors … . Recommended for upper level undergraduates, graduates, researchers and practitioners. - E-Streams, Vol. 7, No. 12, December 2004 Its strong point is that is contains a fantastic wealth of design information on all kinds of motors…It gives the reader a very good understanding of a broad range of modern motor technology…Anyone who designs or works with motors of all types would definitely find this book to be an excellent handbook and guide for understanding the details of motor design and being able to choose the correct motor for a given application. - IEEE Electrical Insulation Magazine, Vol. 21, No. 3, May/June 2005 Product Description Presenting current issues in electric motor design, installation, application, and performance, this second edition serves as the most authoritative and reliable guide to electric motor utilization and assessment i...

A good book that covers the following topics: Concept of e.m.f., p,d.; and Current Resistance; Effect of Temperature on Resistance. Resistance temperature Coefficient; Insulation Resistance; S.I. Units of Work; Power and Energy Conversion of Energy from One Form to Another in Electrical; Mechanical and Thermal Systems. Batteries and Cells; Their Types; Current Capacity and Cell Ratings; Charging and Discharging of Batteries; Series and Parallel Battery Connections; Maintenance Procedure. Classification of Electric Networks; Ohm's Law; Kirchhoff"™s Laws and Their Applications for Networks Solutions Simplification of Networks Using Series and Parallel Combinations and Star-Delta Transformation; Superposition Theorem; Thevenin's Theorem; Norton's Theorem and Maximum Power Transfer Theorem DOWNLOAD LINK 1 DOWNLOAD LINK 2

There are two basic voltage surge that may cause damage to the system and its corresponding equipment and apparatus. These are: 1. Switching Surge 2. Lightning Surge Switching Surge - These are voltage abnormalities that are caused by changes in the operating state of the power system, that involves switching (literally) of breakers, disconnect switches, and other switch gears. It happens as trapped energy are released during the event. Lightning Surge - These are voltage abnormalities caused by the phenomenon of lightning. Damaged may be experienced through direct stroke or hit, or by induced voltages. Lightning are harmful, and runs in millions of voltages, which makes the equipment vulnerable without protection. The risk of having your equipment exposed to both of these abnormalities can be greatly reduced with the application of surge arresters. Not to be confused, surge arresters refers to devices which could protect from the aforementioned abnormalities....

In electric power distribution systems, a wide variety of cable faults can occur. The problem may be in a communication circuit or in a power circuit, either in the low- or medium-voltage class. Regardless of the class of equipment involved or the type of fault, the one common problem is to determine the location of the fault so that repairs can be made. The vast majority of cable faults encountered in an electric power distribution system occur between conductor and ground. Most fault-locating techniques are made with the circuit deenergized. In ungrounded or high-resistance grounded, low-voltage systems, however, the occurrence of a single line-to-ground fault will not result in automatic circuit interruption; therefore, the process of locating the fault may be carried out by special procedures with the circuit energized. Once a line-to-ground fault has occurred, the resistance of the fault path can range from almost zero up to millions of ohms. The fault resista...

A clear explanation of the technology for producing and delivering electricity Electric Power Systems explains and illustrates how the electric grid works in a clear, straightforward style that makes highly technical material accessible. It begins with a thorough discussion of the underlying physical concepts of electricity, circuits, and complex power that serves as a foundation for more advanced material.  Readers are then introduced to the main components of electric power systems, including generators, motors and other appliances, and transmission and distribution equipment such as power lines, transformers, and circuit breakers. The author explains how a whole power system is managed and coordinated, analyzed mathematically, and kept stable and reliable. Recognizing the economic and environmental implications of electric energy production and public concern over disruptions of service, this book exposes the challenges of producing and delivering electricity to hel...

Alexander and Sadiku's Fundamentals of Electric Circuits continues in the spirit of its successful previous editions, with the objective of presenting circuit analysis in a manner that is clearer, more interesting, and easier to understand than other, more traditional texts.  Students are introduced to the sound, six-step problem solving methodology in chapter one, and are consistently made to apply and practice these steps in practice problems and homework problems throughout the text. A balance of theory, worked examples and extended examples, practice problems, and real-world applications, combined with over 350 new homework problems for the fourth edition and robust media offerings, renders the fourth edition the most comprehensive and student-friendly approach to linear circuit analysis. This is a very fine book. It explains the concepts very clearly and maybe used for signals too, when studying fourier and laplace transforms. The authors do a superb job and ...

The most popular electricians' handbook for the past 95 years has been completely updated to provide the latest NEC and NESC rules and standards, and new references to solar power, photovoltaics, induction lighting, and more. Providing all the information you'll need to design, maintain, and operate systems and equipment, American Electricians' Handbook is the key to tackling even the most complex jobs with complete confidence.  This one-stop resource focuses on systems and equipment rather than codes and calculations, making it the most practical, hands-on guide available. No matter what kind of electrical project you plan to take on, the American Electricians' Handbook is the only guide you'll need. American Electrician's Handbook covers: Solar power and photovoltaics Variable- and adjustable-speed drives Variable-speed-drive programming Continuous load calculations Induction lighting New NEC and NESC rules NEMA motor and generato...

The field of industrial electronics covers a plethora of problems which must be solved in industrial practice. Electronic systems control many processes that begin with the control of relatively simple devices like electric motors, through more complicated devices such as robots, to the control of entire fabrication processes. An industrial electronics engineer works with many physical phenomena as well as the sensors which are used to measure them. Thus the knowledge required by this type of engineer is not only traditional electronics but also specialized electronics, such as those required for high power applications.  The importance of electronic circuits extends well beyond their use as a final product in that they are also important building blocks in large systems. Therefore, the industrial electronics engineer must also possess knowledge of the areas of control and mechatronics.  Since most fabrication processes are relatively complex, there is an inh...