This document summarizes different configurations for industrial electrical networks. It describes:
1) Standard voltage ratings defined by IEC 38 for low, medium, and high voltage.
2) The general structure of private distribution networks which typically includes components like HV consumer substations, HV/MV transformers, MV switchboards, MV and LV networks and loads.
3) Common arrangements for HV consumer substations including single power supply, dual power supply, and dual fed double bus systems.
NTDC 220kV Transmission gird station Internship reportAneel-k Suthar
This document provides an overview of Anil Kumar's internship report on the 220/132 kV grid station in Jamshoro-T.M. Khan Road. It includes acknowledgements, an executive summary, and sections on the grid station, one-line diagram, bus bar, switches, relays, transformers, and maintenance. The grid station regulates and controls power flow and supplies electricity to substations. It uses a double bus one and a half breaker scheme, which improves reliability over other schemes by allowing maintenance without power interruptions.
The document provides a typical list of materials required for construction of a 132 kV grid substation, including:
1. Various types of structures/beams, outdoor equipment like transformers, isolators, circuit breakers, current/potential transformers, lightning arresters, post insulators.
2. Control room equipment such as different voltage control and relay panels, battery sets, chargers, distribution boards.
3. Bus bar materials like hardware for single zebra and panther conductors, disc insulators.
The list covers common equipment but is not exhaustive, as additional items may be needed depending on the specific substation layout and requirements. It is intended to aid planning for substation construction projects.
Ishank Ranjan completed an industrial training project at the 220kV Grid Transmission Substation in Naubasta, Kanpur. The report acknowledges the contributions of staff at the substation who helped explain the various equipment. It includes sections on the components used at grid transmission substations such as conductors, transformers, capacitor banks, isolators, circuit breakers and lightning arresters. The report provides details on the panel section which contains control and protection panels, and the substation yard layout.
The document discusses the key elements of distribution systems including feeders, distributors, service mains, and classifications based on current, construction, and connection schemes. It describes the functions of distribution substations and provides examples of radial, ring main, and interconnected systems. The document also covers voltage drop considerations for feeders and distributors, as well as objectives of distribution automation including improved reliability, power quality, and deferred capital expenses.
This document is an internship training report submitted by Muhammad Usman Rafiq to the Department of P&I at IESCO in partial fulfillment of the requirements for a one month internship. The report provides an overview of the equipment used at a 132kv grid substation, including transformers, circuit breakers, bus couplers, incoming and outgoing panels, and batteries/battery chargers. It discusses the components and functions of these devices. The report is dedicated to Usman Rafiq's parents and teachers for their support and includes certificates, acknowledgments, and abstract sections.
This document provides an overview of maintenance of equipment at a 33/11kV substation. It discusses key components like transformers, busbars, insulators, circuit breakers, metering equipment, relays, miscellaneous equipment, and protection systems. It also covers substation design considerations like earthing methodology and materials. The document aims to give an understanding of maintenance needs for high voltage substation equipment.
This document provides an introduction and overview of a 33/11 kV substation in Uttar Pradesh, India. It discusses the key components of the substation including transformers, circuit breakers, insulators, protective equipment. It also covers the types of substations, earthing design methodology, and materials used for earthing. The document aims to provide training on the design, components and operation of electrical substations.
- The document provides details of a 132kV grid station project in Rawalpindi for Islamabad Electric Supply Company, including scope of work, contract values, equipment installed, civil works completed, and diagrams of the site layout, single line diagram, and protection relay circuits. Key equipment installed includes two 31.5/40MVA power transformers, four 132kV circuit breakers, disconnect switches, current and potential transformers, and indoor panels. Civil works included foundations, trenches, roads, fencing and a control house building. Diagrams show the layout and protection schemes.
NTDC 220kV Transmission gird station Internship reportAneel-k Suthar
This document provides an overview of Anil Kumar's internship report on the 220/132 kV grid station in Jamshoro-T.M. Khan Road. It includes acknowledgements, an executive summary, and sections on the grid station, one-line diagram, bus bar, switches, relays, transformers, and maintenance. The grid station regulates and controls power flow and supplies electricity to substations. It uses a double bus one and a half breaker scheme, which improves reliability over other schemes by allowing maintenance without power interruptions.
The document provides a typical list of materials required for construction of a 132 kV grid substation, including:
1. Various types of structures/beams, outdoor equipment like transformers, isolators, circuit breakers, current/potential transformers, lightning arresters, post insulators.
2. Control room equipment such as different voltage control and relay panels, battery sets, chargers, distribution boards.
3. Bus bar materials like hardware for single zebra and panther conductors, disc insulators.
The list covers common equipment but is not exhaustive, as additional items may be needed depending on the specific substation layout and requirements. It is intended to aid planning for substation construction projects.
Ishank Ranjan completed an industrial training project at the 220kV Grid Transmission Substation in Naubasta, Kanpur. The report acknowledges the contributions of staff at the substation who helped explain the various equipment. It includes sections on the components used at grid transmission substations such as conductors, transformers, capacitor banks, isolators, circuit breakers and lightning arresters. The report provides details on the panel section which contains control and protection panels, and the substation yard layout.
The document discusses the key elements of distribution systems including feeders, distributors, service mains, and classifications based on current, construction, and connection schemes. It describes the functions of distribution substations and provides examples of radial, ring main, and interconnected systems. The document also covers voltage drop considerations for feeders and distributors, as well as objectives of distribution automation including improved reliability, power quality, and deferred capital expenses.
This document is an internship training report submitted by Muhammad Usman Rafiq to the Department of P&I at IESCO in partial fulfillment of the requirements for a one month internship. The report provides an overview of the equipment used at a 132kv grid substation, including transformers, circuit breakers, bus couplers, incoming and outgoing panels, and batteries/battery chargers. It discusses the components and functions of these devices. The report is dedicated to Usman Rafiq's parents and teachers for their support and includes certificates, acknowledgments, and abstract sections.
This document provides an overview of maintenance of equipment at a 33/11kV substation. It discusses key components like transformers, busbars, insulators, circuit breakers, metering equipment, relays, miscellaneous equipment, and protection systems. It also covers substation design considerations like earthing methodology and materials. The document aims to give an understanding of maintenance needs for high voltage substation equipment.
This document provides an introduction and overview of a 33/11 kV substation in Uttar Pradesh, India. It discusses the key components of the substation including transformers, circuit breakers, insulators, protective equipment. It also covers the types of substations, earthing design methodology, and materials used for earthing. The document aims to provide training on the design, components and operation of electrical substations.
- The document provides details of a 132kV grid station project in Rawalpindi for Islamabad Electric Supply Company, including scope of work, contract values, equipment installed, civil works completed, and diagrams of the site layout, single line diagram, and protection relay circuits. Key equipment installed includes two 31.5/40MVA power transformers, four 132kV circuit breakers, disconnect switches, current and potential transformers, and indoor panels. Civil works included foundations, trenches, roads, fencing and a control house building. Diagrams show the layout and protection schemes.
TDU - Unit 02 - HVDC, FACTS and sub-stations PremanandDesai
The document discusses HVDC transmission systems and FACTS. It provides details on the components and operation of HVDC systems, including converter stations, filters, transformers, transmission lines, and switchgear. HVDC is described as using DC for long distance, bulk power transmission between asynchronous AC networks, with advantages over HVAC like reduced costs and losses. FACTS are defined as using power electronics to improve transmission system controllability, stability, and power transfer capability. The key objectives and benefits of FACTS are also summarized.
Seminar Report on 220 KV Grid Sub Station on Bundi SahilQureshi14
This document provides an overview of a 220kV grid substation in Bundi, Rajasthan, India. It discusses the purpose and components of grid substations, including transformers, circuit breakers, isolators, buses, current transformers, and other key equipment. It also describes the selection process for the substation site and lists considerations like proximity to load centers, accessibility, and avoidance of flood-prone areas. Various types of substations and transformers are defined. An index lists the topics covered in the document.
The document summarizes the power distribution system for a city located between an industrial area and railway station. A 10 MW small hydro power plant was chosen due to topography and cost. Power is distributed through 4 substations to various areas of the city including 2 railway substations. The protection scheme and equipment used including transformers, circuit breakers and isolators are listed. A single line diagram shows the layout of the generation plant, distributing unit and substations along with feeders.
The slide is basically to show the general knowledge about the System Works for this Electrified Double Track Project between Ipoh & Padang Besar, the Equipments & its Functions.I have presented this slide to my college in Commercial Department and I want to share this little of my contribution to all linked in members.Hope we can get some benefit from this slide.Thank You
The document discusses electrical power distribution systems in Malaysia. It describes the country's national grid system, which transmits power from generation sources via high-voltage transmission lines and distributes it to customers through distribution networks. The main components of distribution systems include substations, distribution feeder circuits, switches, protective equipment, transformers, secondary lines, and services. Malaysia's national grid is owned and operated by TNB and connects generation stations to consumers across Peninsular Malaysia. Sabah and Sarawak each have their own regional grids.
This document provides an overview of HVDC (high voltage direct current) transmission. It discusses the objectives and principles of HVDC systems, including the basic steps of converting AC to DC, transmitting DC power, and converting DC back to AC. The document also covers types of HVDC links, advantages and disadvantages of HVDC transmission, and the basic equipment used in converter stations, including converters, smoothing reactors, and harmonic filters. It provides examples of HVDC projects in India and compares HVDC to HVAC transmission.
1) HVDC transmission began with early DC systems but AC transmission became more widely used in the early 20th century. Developments in valves made HVDC transmission practical again for long distances or underwater cables.
2) HVDC is used when the transmission distance is long, such as for underwater cables or connecting asynchronous AC networks. The converters allow power exchange between incompatible AC systems.
3) Modern HVDC uses thyristor valves arranged in 12-pulse configurations to reduce harmonics. Substations contain converter transformers, filters, reactors and arresters. Applications include connecting remote generation to loads and increasing transmission capacity.
Power line carrier communication (PLCC) allows for telecommunication between electric substations using existing power lines. Data can be transferred at rates up to 9.6 kbps over many miles of cable. PLCC systems use coupling devices like capacitors and line matching units to connect communication equipment to power lines while preventing carrier currents from interfering with power equipment. Common PLCC equipment includes stations, line matching units, control voltage transformers, earth switches, lightning arrestors, wave traps, and coaxial cables. Wave traps are used to block carrier currents from entering power stations to avoid interference. PLCC offers communication without additional wiring but requires safeguarding equipment from high voltages and currents on power lines.
This document discusses the design of a long overhead electric power transmission line from Khulna to Dhaka, Bangladesh using high voltage direct current (HVDC) technology. It provides background on why HVDC transmission is advantageous over alternating current (AC) transmission for long distances. The author analyzes existing AC transmission networks and generation sources between the locations. Electrical parameters and design considerations for both typical AC and proposed HVDC transmission lines are presented. Comparisons of technical performance and costs between HVDC and HVDC systems are also provided. The document considers opportunities and challenges for implementing HVDC transmission.
BSES Rajdhani Power Limited (BRPL) took over power distribution in South and West Delhi from Delhi Vidyut Board in 2002. BRPL has invested over 1,836 crores since 2002-2003 to develop infrastructure and provide quality supply. They plan to electrify unauthorized colonies from 2007-2008 to 2010-2011. The document then discusses the components and functions of substations, including transformers, circuit breakers, capacitors, and other equipment used to transform and distribute power safely. It provides examples of specific substations in Delhi operated by BRPL.
Electricity distribution involves delivering electricity from transmission systems to end users through medium and low voltage power lines, substations, and transformers. Early distribution used direct current at low voltages, but alternating current became dominant due to its ability to change voltages efficiently using transformers. Modern distribution systems use a variety of overhead and underground configurations to deliver power at voltages between 2.3-35kV, depending on the distance and load. International systems differ in voltages used, phase configurations, and the use of centralized vs decentralized transformers.
The document discusses three HVDC transmission systems in New Zealand and India:
1. The HVDC inter-island transmission system in New Zealand consists of three bipolar links that transmit power over 610 km between the North and South Islands, including 40 km of submarine cables under Cook Strait.
2. The +500 kV, 2500 MW HVDC Ballia-Bhiwadi transmission link in India transmits power over 780 km between eastern and northern parts of the country. Each pole can transmit 1250 MW.
3. Key features of HVDC transmission systems include their ability to transmit bulk power over long distances with reduced power losses, and to continue operating at reduced voltages during adverse weather conditions. They
1. The document discusses various aspects of electric traction systems used for rail transport including power supply installation, overhead line equipment, and remote control systems.
2. It describes different types of traction systems including DC traction, AC traction, and multi-system electric traction.
3. The advantages of electric traction systems are highlighted such as cleanliness, low maintenance costs, high starting torque and acceleration.
I have created this report for my final semester seminar at Poornima college of engineering Jaipur, electrical department. This report covers various chapters and other contents. feel free to download.
Note: some minor editsin format and a quick spelling check might be needed.
**content source is wikipedia and internet**
any thing you would like to suggest please let me know in the comments.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document summarizes a training at a 33/11 kV distribution substation. It describes the substation's components including incoming and outgoing lines, isolators, vacuum circuit breakers, busbars, transformers, current transformers, potential transformers, and earthing system. It also discusses the control room, safety procedures, and technical and non-technical skills learned during the training, such as maintenance, management, and proper work procedures. The conclusion states that the training increased understanding of how electricity is transmitted and the substation system.
1. HVDC transmission allows for more efficient long distance power transmission compared to AC transmission by reducing losses. It also allows for interconnection between different frequency AC systems.
2. The key components of an HVDC system are converter stations at each end containing thyristor valves to convert AC to DC or vice versa, transmission lines to carry DC power, and control systems.
3. There are three main conversion technologies: natural commutated converters using thyristors, capacitor commutated converters using thyristors and capacitors, and voltage source converters using devices like GTOs or IGBTs which allow for faster switching.
This document provides a map and locations for various structures at an archaeological site, including pylons, a court, pronaos, hypostyle hall, hall of the altar, vestibule, sanctuary, outer corridor, and nilometer. Each structure is identified and its location on the map is indicated.
This document discusses several common electrical hazards in homes and workplaces. It outlines dangers associated with extension cords such as misuse, damage, and outdoor use. Power lines are also hazardous if contacted by equipment or if within 10 feet. Electric shock can occur from live wires, ungrounded devices, wet conditions, or another person receiving a shock. Safety measures include checking equipment, using GFCIs, and shutting off power before working on circuits. Regular inspections by an electrician can help prevent electrical dangers.
TDU - Unit 02 - HVDC, FACTS and sub-stations PremanandDesai
The document discusses HVDC transmission systems and FACTS. It provides details on the components and operation of HVDC systems, including converter stations, filters, transformers, transmission lines, and switchgear. HVDC is described as using DC for long distance, bulk power transmission between asynchronous AC networks, with advantages over HVAC like reduced costs and losses. FACTS are defined as using power electronics to improve transmission system controllability, stability, and power transfer capability. The key objectives and benefits of FACTS are also summarized.
Seminar Report on 220 KV Grid Sub Station on Bundi SahilQureshi14
This document provides an overview of a 220kV grid substation in Bundi, Rajasthan, India. It discusses the purpose and components of grid substations, including transformers, circuit breakers, isolators, buses, current transformers, and other key equipment. It also describes the selection process for the substation site and lists considerations like proximity to load centers, accessibility, and avoidance of flood-prone areas. Various types of substations and transformers are defined. An index lists the topics covered in the document.
The document summarizes the power distribution system for a city located between an industrial area and railway station. A 10 MW small hydro power plant was chosen due to topography and cost. Power is distributed through 4 substations to various areas of the city including 2 railway substations. The protection scheme and equipment used including transformers, circuit breakers and isolators are listed. A single line diagram shows the layout of the generation plant, distributing unit and substations along with feeders.
The slide is basically to show the general knowledge about the System Works for this Electrified Double Track Project between Ipoh & Padang Besar, the Equipments & its Functions.I have presented this slide to my college in Commercial Department and I want to share this little of my contribution to all linked in members.Hope we can get some benefit from this slide.Thank You
The document discusses electrical power distribution systems in Malaysia. It describes the country's national grid system, which transmits power from generation sources via high-voltage transmission lines and distributes it to customers through distribution networks. The main components of distribution systems include substations, distribution feeder circuits, switches, protective equipment, transformers, secondary lines, and services. Malaysia's national grid is owned and operated by TNB and connects generation stations to consumers across Peninsular Malaysia. Sabah and Sarawak each have their own regional grids.
This document provides an overview of HVDC (high voltage direct current) transmission. It discusses the objectives and principles of HVDC systems, including the basic steps of converting AC to DC, transmitting DC power, and converting DC back to AC. The document also covers types of HVDC links, advantages and disadvantages of HVDC transmission, and the basic equipment used in converter stations, including converters, smoothing reactors, and harmonic filters. It provides examples of HVDC projects in India and compares HVDC to HVAC transmission.
1) HVDC transmission began with early DC systems but AC transmission became more widely used in the early 20th century. Developments in valves made HVDC transmission practical again for long distances or underwater cables.
2) HVDC is used when the transmission distance is long, such as for underwater cables or connecting asynchronous AC networks. The converters allow power exchange between incompatible AC systems.
3) Modern HVDC uses thyristor valves arranged in 12-pulse configurations to reduce harmonics. Substations contain converter transformers, filters, reactors and arresters. Applications include connecting remote generation to loads and increasing transmission capacity.
Power line carrier communication (PLCC) allows for telecommunication between electric substations using existing power lines. Data can be transferred at rates up to 9.6 kbps over many miles of cable. PLCC systems use coupling devices like capacitors and line matching units to connect communication equipment to power lines while preventing carrier currents from interfering with power equipment. Common PLCC equipment includes stations, line matching units, control voltage transformers, earth switches, lightning arrestors, wave traps, and coaxial cables. Wave traps are used to block carrier currents from entering power stations to avoid interference. PLCC offers communication without additional wiring but requires safeguarding equipment from high voltages and currents on power lines.
This document discusses the design of a long overhead electric power transmission line from Khulna to Dhaka, Bangladesh using high voltage direct current (HVDC) technology. It provides background on why HVDC transmission is advantageous over alternating current (AC) transmission for long distances. The author analyzes existing AC transmission networks and generation sources between the locations. Electrical parameters and design considerations for both typical AC and proposed HVDC transmission lines are presented. Comparisons of technical performance and costs between HVDC and HVDC systems are also provided. The document considers opportunities and challenges for implementing HVDC transmission.
BSES Rajdhani Power Limited (BRPL) took over power distribution in South and West Delhi from Delhi Vidyut Board in 2002. BRPL has invested over 1,836 crores since 2002-2003 to develop infrastructure and provide quality supply. They plan to electrify unauthorized colonies from 2007-2008 to 2010-2011. The document then discusses the components and functions of substations, including transformers, circuit breakers, capacitors, and other equipment used to transform and distribute power safely. It provides examples of specific substations in Delhi operated by BRPL.
Electricity distribution involves delivering electricity from transmission systems to end users through medium and low voltage power lines, substations, and transformers. Early distribution used direct current at low voltages, but alternating current became dominant due to its ability to change voltages efficiently using transformers. Modern distribution systems use a variety of overhead and underground configurations to deliver power at voltages between 2.3-35kV, depending on the distance and load. International systems differ in voltages used, phase configurations, and the use of centralized vs decentralized transformers.
The document discusses three HVDC transmission systems in New Zealand and India:
1. The HVDC inter-island transmission system in New Zealand consists of three bipolar links that transmit power over 610 km between the North and South Islands, including 40 km of submarine cables under Cook Strait.
2. The +500 kV, 2500 MW HVDC Ballia-Bhiwadi transmission link in India transmits power over 780 km between eastern and northern parts of the country. Each pole can transmit 1250 MW.
3. Key features of HVDC transmission systems include their ability to transmit bulk power over long distances with reduced power losses, and to continue operating at reduced voltages during adverse weather conditions. They
1. The document discusses various aspects of electric traction systems used for rail transport including power supply installation, overhead line equipment, and remote control systems.
2. It describes different types of traction systems including DC traction, AC traction, and multi-system electric traction.
3. The advantages of electric traction systems are highlighted such as cleanliness, low maintenance costs, high starting torque and acceleration.
I have created this report for my final semester seminar at Poornima college of engineering Jaipur, electrical department. This report covers various chapters and other contents. feel free to download.
Note: some minor editsin format and a quick spelling check might be needed.
**content source is wikipedia and internet**
any thing you would like to suggest please let me know in the comments.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document summarizes a training at a 33/11 kV distribution substation. It describes the substation's components including incoming and outgoing lines, isolators, vacuum circuit breakers, busbars, transformers, current transformers, potential transformers, and earthing system. It also discusses the control room, safety procedures, and technical and non-technical skills learned during the training, such as maintenance, management, and proper work procedures. The conclusion states that the training increased understanding of how electricity is transmitted and the substation system.
1. HVDC transmission allows for more efficient long distance power transmission compared to AC transmission by reducing losses. It also allows for interconnection between different frequency AC systems.
2. The key components of an HVDC system are converter stations at each end containing thyristor valves to convert AC to DC or vice versa, transmission lines to carry DC power, and control systems.
3. There are three main conversion technologies: natural commutated converters using thyristors, capacitor commutated converters using thyristors and capacitors, and voltage source converters using devices like GTOs or IGBTs which allow for faster switching.
This document provides a map and locations for various structures at an archaeological site, including pylons, a court, pronaos, hypostyle hall, hall of the altar, vestibule, sanctuary, outer corridor, and nilometer. Each structure is identified and its location on the map is indicated.
This document discusses several common electrical hazards in homes and workplaces. It outlines dangers associated with extension cords such as misuse, damage, and outdoor use. Power lines are also hazardous if contacted by equipment or if within 10 feet. Electric shock can occur from live wires, ungrounded devices, wet conditions, or another person receiving a shock. Safety measures include checking equipment, using GFCIs, and shutting off power before working on circuits. Regular inspections by an electrician can help prevent electrical dangers.
This document discusses the traceroute command in detail. It begins with an introduction explaining the purpose is to demystify the use of traceroute in analyzing complex routing problems on the internet. It then covers the fundamentals of how traceroute works by sending packets with increasing TTL values, which causes routers to return time exceeded messages at each hop. Finally, it provides a real example traceroute output between two hosts to demonstrate the command in action.
A substation is a part of an electrical distribution system where voltage is transformed from high to low or low to high. Electric power may pass through multiple substations between generation and consumption. Substations are classified as indoor, outdoor, underground, or pole-mounted. They can serve to transform voltage, switch circuits, correct power factors, change frequencies, or supply industrial facilities. Key components include transformers, circuit breakers, surge arrestors, switchgear, and relays. Substations have layouts with primary and secondary sides separated by transformers, circuit breakers, and other equipment.
A substation is a part of an electrical distribution system where voltage is transformed from high to low or low to high. Electric power may pass through multiple substations between generation and consumption. Substations are classified as indoor, outdoor, underground, or pole-mounted. They can serve to transform voltage, switch circuits, correct power factors, change frequencies, or supply industrial facilities. Key components include transformers, circuit breakers, surge arrestors, switchgear, and relays. Substations have layouts to safely distribute primary and secondary power lines.
The document promotes creating presentations using Haiku Deck, stating that users can make their own Haiku Deck presentations on SlideShare and including a button prompting users to "GET STARTED". It provides high-level information about creating Haiku Deck presentations in a concise 3 sentence summary as requested.
This document summarizes a 220kV substation in Kanpur, India. It describes that a substation transforms voltage from high to low levels using transformers. It then details the components of the 220kV substation, including the panel section with control and relay panels, and the switchyard with components like circuit breakers and transformers. It provides information on the incoming 220kV lines and outgoing 132kV and 33kV lines. It concludes that substantial infrastructure is required to deliver electricity to homes.
Our business model focuses on providing advice and partnership to clients by understanding their individual problems rather than pushing products and solutions, as we aim to propose customized solutions that specifically address each client's unique challenges in order to help them succeed.
A circuit breaker is a device that breaks an electrical circuit automatically or manually under normal, full, or short circuit conditions. It contains two contacts that remain closed under normal operation but separate when a fault is detected, interrupting the current. When the contacts separate, an arc is struck but continues the current flow. Circuit breakers must extinguish the arc quickly. There are different types of circuit breakers including oil, air blast, SF6, and vacuum that use various insulating mediums like oil, air, sulfur hexafluoride gas, or vacuum to rapidly extinguish the arc. SF6 circuit breakers are commonly used for high voltages as SF6 gas strongly absorbs electrons from the arc to build insulation and ext
Wastewater treatment involves several stages to manage water discharged from homes, businesses, and industries. These stages include pre-treatment, preliminary treatment, primary treatment, secondary treatment, and sludge disposal. The goal is to reduce water pollution by decreasing levels of suspended solids and biochemical oxygen demand through physical and biological processes before water is discharged back into local waterways.
This document summarizes a seminar on circuit breakers. It discusses the working principles of circuit breakers, including arc phenomenon and methods of arc extinction. It also covers terms related to circuit breakers and different types of circuit breakers such as oil, air blast, sulfur hexafluoride, and vacuum circuit breakers. For each type, it provides details on principles of operation, advantages, disadvantages, and applications. The document concludes that the seminar helped gather new information about circuit breakers and their role in power systems.
This short document promotes the creation of presentations using Haiku Deck, an online presentation tool. It includes two stock photos and text suggesting the reader may be inspired to create their own Haiku Deck presentation. A call to action is given to get started using the tool on SlideShare.
The document provides an overview of the importance and purposes of engineering drawings for electrical engineers. It discusses how drawings are used at various stages of engineering projects to effectively plan, communicate, and execute designs. The document also outlines important international standards for drafting drawings, including standards for dimensions, tolerances, symbols, and graphical representation. Maintaining consistent standards is important for ensuring drawings are clear and accurately convey design information.
Crypto-currencies (bitcoin et al) have caught the attention of Governments, enforcement agencies, geeks and the general public.
This document provides a simple introduction to crypto-currencies and briefly introduces terms such as cryptography, hash functions, proof-of-work, digital signatures, mining, merkle root & tree, crypto-currency addresses and wallets.
This document is intended for the novice reader and may suffer from errors inherent when a complex topic is (over?) simplified.
Introduction to blockchain and crypto currenciesRohas Nagpal
This document provides an overview of blockchain technology and cryptocurrencies. It begins with definitions of money, including fiat currency, e-money, and virtual currency. It then discusses key concepts related to cryptocurrencies like Bitcoin, including how they use cryptography, hash functions, digital signatures, proof-of-work, and blockchains to achieve decentralization. The document also examines common terminology in the space like miners, addresses, and wallets. Finally, it provides examples of how Bitcoin is being used in the real world, such as with ATMs, online purchases, and even lotteries and laundering.
The document is a product catalogue from 3M for electrical cable accessories. It provides information on 3M's range of electrical tapes, including PVC insulating tapes, self-amalgamating tapes, and mastic sealing tapes. Various tape products are described, along with their features, applications, and sizing options. The catalogue also lists other cable-related products such as joints, terminations, connectors, tools, and locating/marking systems.
The document discusses the general structure of electricity networks and energy distribution conditions. It can be summarized as follows:
1. Electricity is distributed through a network of high voltage lines for long distances and lower voltages for shorter distances to consumers. This includes transmission, distribution, and local distribution networks.
2. Electricity distribution involves production centers, switching stations, transformer substations to step down voltages, and distribution to large industrial users and smaller residential and commercial users.
3. Integrating new distributed energy sources like wind and solar is challenging due to their variability, requiring balancing of supply and demand on the network.
This document provides an overview of power grid design. It discusses the key components of an electrical grid including power generation, transmission, and distribution. Power is generated at stations and stepped up for transmission over long distances via transmission lines before being stepped down for distribution. Grid design involves selecting sites and bus bar schemes, determining bill of materials, ensuring safety clearances, designing earth mats, and laying out control rooms and equipment. Factors like proximity to load centers, accessibility, and avoidance of obstructions must be considered for site selection. Common bus bar schemes include single, main-auxiliary, double, and one-and-a-half breaker configurations. Proper grid design is important for reliably and safely delivering power.
Simulation of H6 full bridge Inverter for grid connected PV system using SPWM...IRJET Journal
This document proposes a new H6 full bridge inverter topology for grid-connected photovoltaic systems using sinusoidal pulse width modulation (SPWM) technique. It aims to reduce common mode leakage currents compared to existing H5 and HERIC inverter topologies. The H6 topology adds two additional switches to the DC side of the full bridge inverter. SPWM pulses for the additional switches are designed to keep the common mode voltage constant during all operating modes, which effectively reduces leakage currents. The MATLAB simulation software is used to simulate the proposed H6 inverter topology and validate the concept.
The document discusses substations, their components, and an experiment on power system design. It defines substations as parts of the electrical generation and distribution system that transform voltage levels. There are four main types: transmission substations connect transmission lines; distribution substations transfer power from transmission to distribution networks; collector substations collect power from distributed generation sources; and switching substations switch currents without transformers. The key components discussed are busbars to distribute current, circuit breakers for protection, transformers, conductors, isolators, and insulators. The experiment aims to study these concepts through observation and calculations.
Review of Reduction of Leakage Current in Cascaded Multilevel InverterIJRST Journal
Multilevel inverters are a source of high power, often used in industrial applications and can use either sine or modified sine waves. A multilevel inverter uses a series of semiconductor power converters (usually two to three) thus generating higher voltage. Reverse leakage current in a semiconductor device is the current from that semiconductor device when the device is reverse biased. In earlier method transformer is used for generating multilevel output and grid synchronization. Transformer increases the leakage current. Now transformerless method and sine modulation techniques are presented to reduce the leakage current.
ZVS Circuit based – Cockcroft Walton High Voltage DC GeneratorIRJET Journal
This document describes a ZVS (zero voltage switching) circuit based Cockcroft Walton high voltage DC generator. It begins with an abstract that outlines the uses of high voltage DC power supplies and discusses the challenges with existing designs. It then provides details of the key components in the proposed design - a ZVS driver to generate high frequency AC, a flyback transformer to boost the voltage, and a Cockcroft Walton voltage multiplier to produce high voltage DC output. The advantages of this design are improved performance, lower cost due to using fewer stages, and increased flexibility and portability by operating on a small battery. Applications discussed include cable insulation testing, impulse generators, particle accelerators, and medical X-ray equipment.
This document provides an overview of a 220/66kV substation in Punjab, India. It discusses the key components and functions of the substation, including transformers, circuit breakers, busbars, insulators, overhead lines, and protection equipment. The substation steps down electricity from 220kV to 66kV for distribution. It also discusses the roles and specifications of important equipment like current transformers, potential transformers, conductors, and capacitor banks.
Abstract- This paper presents a major revision of the Universal Four Leg ‘DC Grid Laboratory Experimental Setup’. This revision includes the reduction of current loops, the increase of efficiency in the power stage, the expansion of measurement possibilities and the re-specification of the input/output range.
To deal with an ever present complication in the world of measurements, simple fuse holders are converted into dedicated probe measurement connectors. These connectors reduce large ground loops to a minimum.
Key features include a clear board layout and silkscreen, a tremendous reduction of semiconductor losses resulting in a heatsink-less power stage and easy, reliable probe and power connections. Provisions are made for a Single Board Computer (SBC) to read and control the Universal Four Leg V4. The SBC can also be used to communicate with external devices to allow for remote control of the Universal Four Leg and the presentation of measurements performed.
The Universal Four Leg is a power management device with a wide range of applications in both higher educational laboratory courses, as well as a dedicated grid manager in low voltage DC-grids.
The document discusses the design and components of electrical power grids. It begins with an introduction to power grids, noting their three main components: power stations, transmission lines, and transformers. It then covers various topics related to designing a power grid substation including selecting the site, layout designs, busbar schemes, safety clearances, earth mat design, and control rooms. Key equipment for grids are also discussed such as lighting arrestors, current and potential transformers, circuit breakers, and isolators. The presentation concludes that grids are important for supplying reliable and economic power from sources to loads and maintaining efficiency, though their design and components make them costly.
The document provides information about Noida Metro Rail Corporation Limited (NMRC). It discusses that NMRC is a joint venture between the governments of India and Uttar Pradesh. The metro line connects Noida and Greater Noida, with 21 stations along the 29.7 km route. It then provides details about the electrical department, including the power distribution system, auxiliary power system, traction power system using 25kV AC overhead lines, and train configuration with pantographs and other electrical equipment. Battery configurations and workshop power supplies are also summarized.
The document provides an overview of the 33/11kV Phidim substation located in Phidim, Panchthar district, Nepal. It was established in 2058 BS by Nepal Electricity Authority. The substation steps down electricity from the national 33kV grid to 11kV to supply power to local areas. It is responsible for controlling energy exchange, load shedding, fault analysis and improving the transmission system. The substation layout, single line diagram, and organizational structure are presented. Key equipment used includes transformers, circuit breakers, isolators, lightning arrestors, and insulators.
Comparision of pi, fuzzy & neuro fuzzy controller based multi converter unifi...IAEME Publication
The document summarizes a research paper that proposes a Neuro-Fuzzy controller for a Multi Converter Unified Power Quality Conditioner (MC-UPQC) device. The MC-UPQC uses multiple voltage source converters to compensate voltage sags/swells and harmonics on multiple feeder lines simultaneously. Conventionally, a PI controller is used for DC link voltage regulation but it has slow response. The proposed Neuro-Fuzzy controller combines the advantages of Fuzzy Logic and Neural Network controllers. It uses the error voltage and change in error as inputs to separate Fuzzy and Neural Network controllers. This improves the transient response and reduces DC link capacitor charging time compared to PI and Fuzzy controllers alone. Simulation results verify the effectiveness of
Introduction to electric power transmission and distributionABDULRAHMANALGHANIM
The document provides an overview of electric power transmission and distribution systems. It discusses how electric power is generated at power stations and stepped up to high voltages for transmission through networks of transmission lines. It then explains how power is stepped down at substations for distribution through primary and secondary distribution networks to reach customers. The key components and classifications of distribution systems are also outlined.
The document discusses a SCADA system for electrical distribution implemented by Jamshedpur Utilities and Services Company (JUSCO). JUSCO uses a SCADA system monitored from its Network Monitoring and Control Centre (NMCC) to automate power distribution. The document outlines various field equipment in the electrical distribution network like transformers, breakers, buses that are monitored by the SCADA system. It also discusses the communication infrastructure and control room setup used for the SCADA system.
The document discusses a SCADA system for electrical distribution implemented by Jamshedpur Utilities and Services Company (JUSCO). JUSCO uses a SCADA system monitored from its Network Monitoring and Control Centre (NMCC) to automate power distribution. The document outlines various field equipment in the electrical distribution network like transformers, breakers, buses that are monitored by the SCADA system. It also discusses the communication infrastructure and control room setup used for the SCADA system.
The document provides an overview of distribution networks by defining distribution systems, describing their location and function within power systems, and identifying their key components. It discusses how distribution systems distribute power from transmission networks to customers by stepping voltages down through substations. The major components of distribution systems are described as bulk power substations, primary feeders, and secondary feeders. Common distribution voltages, substation types, and supply categories are also outlined.
To Diminish the Voltage Sag Replaced DVR with Generalized Modulation Strategy...IRJET Journal
This document discusses replacing a conventional Dynamic Voltage Restorer (DVR) with a matrix converter to compensate for voltage sags. A DVR injects voltage to maintain the load voltage during disturbances. Conventional DVRs use bulky AC-DC-AC converters. The proposed model replaces this with a matrix converter to avoid energy storage and allow for higher power density. A matrix converter directly converts AC to AC using bi-directional switches. It can compensate for voltage sags and swells more efficiently than a conventional DVR without energy storage limitations. Simulation results show the DVR with matrix converter effectively regulates voltage during faults.
Application of single phase matrix converter topology to an uninterruptible p...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Most homes receive a single-phase 230V, 50Hz electricity supply from the local grid. This supply enters the property through underground ducts or overhead lines and passes through the electric meter and main fuse before reaching the distribution board. The distribution board contains circuit breakers that divide the main supply into separate circuits for different areas of the home, providing protection from overloads and faults. It connects to socket outlets and light fittings throughout the building via sub-circuits.
1. 24
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1. NETWORK CONFIGURATIONS
definition
Standard IEC 38 defines voltage ratings as follows:
- Low voltage (LV)
For a phase-to-phase voltage between 100 V and 1000 V. The standard ratings
are: 400 V - 690 V - 1000 V (at 50 Hz)
- Medium voltage (MV)
For a phase-to-phase voltage between 1000 V and 35 kV. The standard ratings
are: 3.3 kV - 6.6 kV - 11 kV - 22 kV - 33 kV
- High voltage (HV)
For a phase-to-phase voltage between 35 kV and 230 kV. The standard ratings
are: 45 kV - 66 kV - 110 kV - 132 kV - 150 kV - 220 kV.
1.1. General structure of the private distribution network
Generally, with an HV power supply, a private distribution network comprises (see fig. 1-1):
- an HV consumer substation fed by one or more sources and made up of one or more
busbars and circuit-breakers
- an internal production source
- one or more HV/MV transformers
- a main MV switchboard made up of one or more busbars
- an internal MV network feeding secondary switchboards or MV/LV substations
- MV loads
- MV/LV transformers
- low voltage switchboards and networks
- low voltage loads.
2. 25
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
HV consumer
substation
internal
production
main MV distribution switchboard
MV
LV
MV
LV
MV
LV
MV
LV
supply source
HV
MV
MV internal distribution
network
LV switchboards
and LV distribution
secondary MV
distribution switchboards
MV load MV load MV load
LV
load
LV
load
Figure 1-1: general structure of a private distribution network
3. 26
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.2. The supply source
The power supply of industrial networks can be in LV, MV or HV. The voltage rating of the supply source
depends on the consumer supply power. The greater the power, the higher the voltage must be.
1.3. HV consumer substations
The most usual supply arrangements adopted in HV consumer substations are:
single power supply (see fig. 1-2)
NC
NC
NC
NC
supply source
HV busbar
to main MV switchboard
NC
Figure 1-2: single fed HV consumer substation
advantage: Reduced cost
drawback: Low availability
N.B.: the isolators associated with the HV circuit-breakers have not been shown.
4. 27
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual power supply (see fig. 1-3)
NC
NC
NC
NC
source 1
HV busbar
to main MV switchboard
NC
NCNC
source 2
MV
HV
MV
HV
devices
operated
by the
utility
Figure 1-3: dual fed HV consumer substation
operating mode:
- normal: Both incoming circuit-breakers are closed, as well as the coupler isolator.
The transformers are thus simultaneously fed by 2 sources.
- disturbed: If one source is lost, the other provides the total power supply.
advantages:
- good availability in that each source can supply the entire network
- maintenance of the busbar possible while it is still partially operating
drawbacks:
- more costly solution than the single power supply system
- only allows partial operation of the busbar if maintenance is being carried out on it
N.B.: the isolators associated with the HV circuit-breakers have not been shown.
5. 28
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual fed double bus system (see fig. 1-4)
NC
NC
source 1
to main MV switchboard
NC NO
Out1
NC NO
Out2
NO NC
Out3
NC
NC
NO NC
Out4
NC
NC or NO
NC NO NO NC
NC
source 2
BB2
BB1
coupler
HV double
busbar
NC NC
HV
MV
HV
MV
Figure 1-4: dual fed double bus HV consumer substation
operating mode:
- normal: Source 1 feeds busbar BB1 and feeders Out1 and Out2.
Source 2 feeds busbar BB2 and feeders Out3 and Out4.
The bus coupler circuit-breaker can be kept closed or open.
- disturbed: If one source is lost the other provides the total power supply.
If a fault occurs on a busbar (or maintenance is carried out on it), the bus
coupler circuit-breaker is tripped and the other busbar feeds all the outgoing
lines.
advantages :
- good supply availability
- highly flexible use for the attribution of sources and loads and for busbar maintenance
- busbar transfer possible without interruption (when the busbars are coupled, it is possible to
operate an isolator if its adjacent isolator is closed).
drawback:
- more costly in relation to the single busbar system
N.B.: the isolators associated with the HV circuit-breakers have not been shown.
6. 30
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.4. MV power supply
We shall first look at the different MV service connections and then the MV consumer
substation.
1.4.1. Different MV service connections
According to the type of MV network, the following supply arrangements are commonly
adopted.
single line service (see fig. 1-5)
overhead line
NC
Figure 1-5: single line service
The substation is fed by a single circuit tee-off from an MV distribution (cable or line). Up to
transformer ratings of 160 kVA this type of MV service is very common in rural areas. It has
one supply source via the utility.
7. 31
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
ring main principle (see fig. 1-6)
NCNCNC
underground
cable ring main
Figure 1-6: ring main service
Ring main units (RMU) are normally connected to form an MV ring main or interconnector-
distributor, such that the RMU busbars carry the full ring main or interconnector current.
This arrangement provides the user with a two-source supply, thereby reducing considerably
any interruption of service due to system faults or switching operations by the supply authority.
The main application for RMU's is in public-supply MV underground cable networks in urban
areas.
8. 32
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
parallel feeder (see fig. 1-7)
NCNONC
parallel
underground-cable
utility
Figure 1-7: duplicated supply service
When an MV supply connection to two lines or cables originating from the same busbar of a
substation is possible, a similar MV switchboard to that of an RMU is commonly used.
The main operational difference between this arrangement and that of an RMU is that the two
incoming panels are mutually interlocked, such that only one incoming switch can be closed at
a time, i.e. its closure prevents that of the other.
On loss of power supply, the closed incoming switch must be opened and the (formerly open)
switch can then be closed. The sequence may be carried out manually or automatically. This
type of switchboard is used particularly in networks of high load density and in rapidly
expanding urban areas supplied by MV underground cable systems.
9. 33
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.4.2. MV consumer substations
The MV consumer substation may comprise several MV transformers and outgoing feeders.
The power supply may be a single line service, ring main principle or parallel feeder
(see § 1.4.1).
Figure 1.8 shows the arrangement of an MV consumer substation using a ring main supply
with MV transformers and outgoing feeders
NCNC
VT
NC
CT
NC NC NC NC
MV feeders
MV
LV
MV
LV
Figure 1-8: MV consumer substation
10. 34
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.5. MV networks inside the site
MV networks are made up of switchboards and the connections feeding them. We shall first of
all look at the different supply modes of these switchboards, then the different network
structures allowing them to be fed.
Note: the isolators and drawout systems which allow maintenance to be carried out on the installation
have not been shown on the diagrams.
1.5.1. MV switchboard power supply modes
We shall start with the main power supply solutions of an MV switchboard, regardless of its
place in the network.
The number of sources and the complexity of the switchboard differ according to the level of
dependability required.
The diagrams have been classed in order of improving dependability but increasing installation
cost.
1 busbar, 1 supply source (see fig. 1-9)
source
MV busbar
NC
MV feeders
Figure 1-9: 1 busbar, 1 supply source
operation: if the supply source is lost, the busbar is put out of service until the fault is
repaired.
11. 35
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1 busbar with no coupler, 2 supply sources (see fig. 1-10)
source 1
MV busbar
NC
MV feeders
source 2
NC or NO
Figure 1-10: 1 busbar with no coupler, 2 supply sources
operation: both sources can operate in parallel or one source can back up the other. If a fault
occurs on the busbar (or maintenance is carried out on it), the outgoing feeders are no longer
fed.
2 bus sections with coupler, 2 supply sources (see fig. 1-11)
source 1
MV busbar
NC
MV feeders
source 2
NC
NC or NO
Figure 1-11: 2 bus sections with coupler, 2 supply sources
operation: the coupler circuit-breaker can be held closed or open. If it is open, each source
feeds one bus section. If one source is lost, the coupler circuit-breaker is closed and the other
source feeds both bus sections.
If a fault occurs on a bus section (or maintenance is carried out on it), only one part of the
outgoing feeders is no longer fed.
12. 36
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1 busbar with no coupler, 3 supply sources (see fig. 1-12)
source 3
MV busbar
NC
MV feeders
source 2
NC
source 1
NC or NO
Figure 1-12: 1 busbar with no coupler, 3 supply sources
operation: the three sources can operate in parallel or one source can back up the other two.
If If a fault occurs on a bus section (or maintenance is carried out on it), the outgoing feeders
are no longer fed.
3 bus sections with couplers, 3 supply sources (see fig. 1-13)
source 1
MV busbar
NC
MV feeders
source 2
NC
NC or NO NC or NO
source 3
NC
Figure 1-13: 3 bus sections with couplers, 3 supply sources
operation: both bus coupler circuit-breakers can be kept open or closed. If they are open,
each supply source feeds its own bus section. If one source is lost, the associated coupler
circuit-breaker is closed, one source feeds 2 bus sections and the other feeds one bus section.
If a fault occurs on one bus section (or if maintenance is carried out on it), only one part of the
outgoing feeders is no longer fed.
13. 37
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
"duplex" distribution system (see fig. 1-14)
source 1
NC
Out1
NO
NC
BB2
BB1
MV double
busbar
MV feeders
coupler
NC
Out2
NC
Out3
NC
Out4
source 2
NC
Figure 1-14: "duplex" distribution system
operation: The coupler circuit-breaker is held open during normal operation. Each source can
feed one or other of the busbars via its two drawout circuit-breaker cubicles. For economic
reasons, there is only one circuit-breaker for the two drawout cubicles which are installed
alongside one another. It is thus easy to move the circuit-breaker from one cubicle to the other.
Thus, if source 1 is to feed busbar BB2, the circuit-breaker is moved into the other cubicle
associated with source 1.
The same principle is used for the outgoing feeders. Thus, there are two drawout cubicles and
only one circuit-breaker associated with each outgoing feeder. Each outgoing feeder can be
fed by one or other of the busbars depending on where the circuit-breaker is positioned. For
example, source 1 feeds busbar BB1 and feeders Out1 and Out2. Source 2 feeds busbar BB2
and feeders Out3 and Out4.
If one source is lost, the coupler circuit-breaker is closed and the other source provides the
total power supply.
If a fault occurs on one of the busbars (or maintenance is carried out on it), the coupler circuit-
breaker is opened and each circuit-breaker is placed on the busbar in service, so that all the
outgoing feeders are fed.
The drawback of the "duplex" system is that it does not allow automatic switching. If a fault
occurs, each changeover lasts several minutes and requires the busbars to be de-energized.
14. 38
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
2 busbars, 2 connections per outgoing feeder, 2 supply sources (see fig. 1-15)
source 1
NO NC
Out1
NO NC
Out2
NC NO
Out3
NC NO
Out4
NC
NO
NC NO NO NC
NC
source 2
BB2
BB1
coupler MVdouble
busbar
MV feeders
Figure 1-15: 2 busbars, 2 connections per outgoing feeder, 2 supply sources
operation: the coupler circuit-breaker is held open during normal operation. Each outgoing
feeder can be fed by one or other of the busbars depending on the state of the isolators which
are associated with it and only one isolator per outgoing feeder must be closed.
For example, source 1 feeds busbar BB1 and feeders Out1 and Out2.
Source 2 feeds busbar BB2 and feeders Out3 and Out4.
If one source is lost, the coupler circuit-breaker is closed and the other source provides the
total power supply.
If a fault occurs on a busbar (or maintenance is carried out on it), the coupler circuit-breaker is
opened and the other busbar feeds all the outgoing feeders.
15. 39
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
2 interconnected double busbars (see fig. 1-16)
source 1
NC NO
Out1
NC NO
Out2
NO NC
Out3
NO NC
Out4
NC
NO
NC NO
BB2
BB1
2 MV double
bus switchboards
MV feeders
NO
CB1
NO
CB2
NO
NO NC
NC
source 2
Figure 1-16: 2 interconnected double busbars
operation: this arrangement is almost identical to the previous one (2 busbars, 2 connections
per feeder, 2 supply sources). The splitting up of the double busbars into two switchboards
with coupler (via CB1 and CB2) provides greater operating flexibility. Each busbar feeds a
smaller number of feeders during normal operation.
16. 40
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.5.2. MV network structures
We shall now look at the main MV network structures used to feed secondary switchboards
and MV/LV transformers. The complexity of the structure differs depending on the level of
dependability required.
The following MV network supply arrangements are the ones most commonly adopted:
single fed radial network (see fig. 1-17)
MV
LV
switchboard2
source 1
NC
source 2
NC
NO
main MV switchboard
switchboard1
MV
LV
Figure 1-17: MV single fed radial network
- the transformers and switchboards 1 and 2 are fed by a single source and there is no back-up
supply
- this structure should be used when availability is not a high requirement and it is often adopted
for cement works networks.
17. 41
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual fed radial network with no coupler (see fig. 1-18)
switchboard2
source 1
NC
source 2
NC
NO
main MV switchboard
switchboard1
MV
LV
NC NC NCNC
MV
LV
NC NO
MV
LV
NCNO
Figure 1-18: MV dual fed radial network with no coupler
- switchboards 1 and 2 are fed by 2 sources with no coupler, the one backing up the other
- availability is good
- the fact that there is no source coupler for switchboards 1 and 2 renders the network less
flexible to use.
18. 42
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual fed radial network with coupler (see fig. 1-19)
switchboard2
source 1
NC
source 2
NC
NO
main MV switchboard
MV
LV
NC NC NCNC
NO
switchboard1
NO
NC
NC NC
NC
Figure 1-19: MV dual fed radial network with coupler
Switchboards 1 and 2 are fed by 2 sources with coupler. During normal operation, the bus
coupler circuit-breakers are open.
- each bus section can be backed up and fed by one or other of the sources
- this structure should be used when good availability is required and it is often adopted in the
iron and steel and petrochemical industries.
19. 43
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
loop system
This system is suitable for widespread networks with large future extensions.
There are two types depending on whether the loop is open or closed during normal
operation.
open loop (see fig. 1-20 a)
source 1
NC
source 2
NC
NC or NO
main MV switchboard
switchboard 1
LV LV LV
NC NC NC NO NC NC
switchboard 2 switchboard 3
MV MV MV
A B
Figure 1-20 a: MV open loop system
- the loop heads in A and B are fitted with circuit-breakers.
- switchboards 1, 2 and 3 are fitted with switches.
- during normal operation, the loop is open (on the figure it is open at switchboard 2).
- the switchboards can be fed by one or other of the sources.
- reconfiguration of the loop enables the supply to be restored upon occurrence of a fault or
loss of a source (see § 10.1.7.1 of the Protection guide).
- this reconfiguration causes a power cut of several seconds if an automatic loop
reconfiguration control has been installed. The cut lasts at least several minutes or dozens
of minutes if the loop reconfiguration is carried out manually by operators.
20. 44
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
closed loop (see fig. 1-20 b)
source 1
NC
source 2
NC
NC
main MV switchboard
switchboard 1
LV LV LV
NC NC NC NC NC NC
switchboard 2 switchboard 3
MV MV MV
Figure 1-20 b: MV closed loop system
- all the loop switching devices are circuit-breakers.
- during normal operation, the loop is closed.
- the protection system ensures against power cuts due to a fault (see § 10.1.8 of the
Protection guide).
This system is more efficient than the open loop since it avoids power cuts.
On the other hand, it is more costly since it requires circuit-breakers in each switchboard and
a more developed protection system.
21. 45
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
parallel feeder (see fig. 1-21)
source 1
NC
source 2
NC
NC or NO
main MV switchboard
LV
LV
LV
NC
NO
NO
NC
NO
NC
switchboard 1
switchboard 2
switchboard 3
MV
MV
MV
NC NC
Figure 1-21: MV parallel feeder network
- switchboards 1, 2 and 3 can be backed up and fed by one or other of the sources
independently.
- this structure is suitable for widespread networks with limited future extensions and which
require good availability.
22. 46
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.6. LV networks inside the site
We shall first of all study the different low voltage switchboard supply modes. Next, we shall
look at the supply schemes for switchboards backed up by generators or an uninterruptible
power supply.
1.6.1. LV switchboard supply modes
We are now going to study the main supply arrangements for an LV switchboard, regardless of
its place in the network. The number of supply sources possible and the complexity of the
switchboard differ according to the level of dependability required.
single fed LV switchboards
example (see fig. 1-22) :
supply source
MV
LV
S1
S3
S2
Figure 1-22: single fed LV switchboards
Switchboards S1, S2 and S3 have only one supply source. The network is said to be of the
arborescent radial type.
If a switchboard supply source is lost, the switchboard is put out of service until the supply is
restored.
23. 47
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual fed LV switchboards with no coupler
example (see fig. 1-23):
source 1
MV
LV
source 2
MV
LV
CB1 CB2
NC NC
NO NC
CB3 CB4
S1
S2
source 3
MV
LV
Figure 1-23: dual fed LV switchboards with no coupler
Switchboard S1 has a dual power supply with no coupler via 2 MV/LV transformers.
Operation of the S1 power supply :
- both sources feed switchboard S1 in parallel.
- during normal operation only one circuit-breaker is closed (CB1 or CB2).
Switchboard S2 has a dual power supply with no coupler via an MV/LV transformer and
outgoing feeder coming from another LV switchboard.
Operation of the S2 power supply:
- one source feeds switchboard S2 and the second provides a back-up supply.
- during normal operation only one circuit-breaker is closed (CB3 or CB4)
24. 48
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
dual fed LV switchboards with coupler
example (see fig. 1-24):
source 1
MV
LV
CB1
NC
CB4
S2
source 2
MV
LV
CB2
NC
CB3
NOS1
source 3
MV
LV
NC
CB6
NO
CB5NC
NC
Figure 1-24: dual fed LV switchboards with coupler
Switchboard S1 has a dual power supply with coupler via 2 MV/LV transformers.
Operation of the S1 power supply: during normal operation, the coupler circuit-breaker CB3 is
open. Each transformer feeds a part of S1. If a supply source is lost, the circuit-breaker CB3 is
closed and a single transformer feeds all of S1.
Switchboard S2 has a dual power supply with coupler via an MV/LV transformer and an
outgoing feeder coming from another LV switchboard.
Operation of the S2 power supply: during normal operation, the circuit-breaker CB6 is open.
Each source feeds part of S2. If a source is lost, the coupler circuit-breaker is closed and a
single source feeds all of S2.
25. 49
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
triple fed LV switchboards with no coupler
example (see fig. 1-25):
source 1
NO
source 2
MV
LV
NC
S1
source 3
MV
LV
NC
NC
Figure 1-25: triple fed LV switchboards with no coupler
Switchboard S1 has a triple power supply with no coupler via 2 MV/LV transformers and an
outgoing feeder coming from another LV switchboard.
During normal operation, the switchboard is fed by 2 transformers in parallel. If one or both of
the transformers fail, switchboard S1 is fed by the outgoing feeder coming from another
switchboard.
26. 50
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
triple fed switchboards with coupler
example (see fig. 1-26):
source 1
NC
source 2
MV
LV
NC
CB1
NO
S1
source 3
MV
LV
NC
CB2
NO
NC
Figure 1-26: triple fed LV switchboards with coupler
Switchboard S1 has a triple power supply with coupler via 2 MV/LV transformers and an
outgoing feeder coming from another LV switchboard.
During normal operation, the two coupler circuit-breakers are open and switchboard S1 is fed
by 3 supply sources.
If one source fails, the circuit-breaker of the associated source is closed and the incoming
circuit-breaker of the source that has been lost is tripped.
27. 51
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.6.2. LV switchboards backed up by generators
example 1: 1 transformer and 1 generator (see fig. 1-27)
source 1
MV
LV
NC
CB1
S2
S1
NO CB2NC
G
non priority circuits
mains/standby
priority circuits
Figure 1-27: 1 transformer and 1 generator
During normal operation CB1 is closed and CB2 open. Switchboard S2 is fed by the
transformer. If the main source is lost, the following steps are carried out:
1. The mains/standby changeover switch is operated and CB1 is tripped.
2. Load shedding if necessary of part of the loads on the priority circuit in order to limit the load
impact on the generator.
3. Start-up of the generator.
4. CB2 is closed when the frequency and voltage of the generator are within the required
ranges.
5. Reloading of loads which may have been shed during step 2.
Once the main source has been restored, the mains/standby changeover device switches the
S2 supply to the mains and the generator is stopped.
28. 52
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 2: 2 transformers and 2 generators (see fig. 1-28)
CB2 S1
G
NO
CB3
priority circuits
G
source 1
TR1
LV
CB4
source 2
TR2
LV
CB5
CB1
NO
S2
NC
S3
MV MV
NC NC
non priority circuits
mains / standby
Figure 1-28: 2 transformers and 2 generators
During normal operation, the coupler circuit-breaker CB1 is open and the mains/standby
changeover device is in position CB2 closed and CB3 open. Switchboard S1 is fed by
transformer TR2.
If source 2 is lost or there is a breakdown on TR2, the S1 (and part of S2) standby supply is
given priority by transformer TR1, after reclosing of the coupler circuit-breaker CB1.
The generators are only started-up after the loss of the 2 main supply sources or the S2
busbar.
The steps for saving the priority circuit supply are carried out in the same way as in
example 1.
29. 53
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.6.3. LV switchboards backed up by an uninterruptible power supply (UPS)
The main devices making up a UPS system are shown in figure 1-29 and table 1-1.
~
_ ~
_
network 2
supply network
incoming
feeders
network 1
(5) manual by-pass
(4) static contactor
(8) switch
(7) switch
or
circuit-breaker
(1) rectifier-
charger
(2) battery
(3) inverter
(6) battery circuit-breaker
(9) switch
load
NC
NO
NCNC
NC
Figure 1-29: uninterruptible power supply system
30. 54
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
Device name Ref. n° Function
Rectifier-charger (1) Transforms the alternating voltage of a supply network into
a direct voltage which will:
- feed the inverter on the one hand,
- continually provide the charge of the storage battery on
the other
Storage battery (2) Provides a back-up supply to feed the inverter in case:
- the supply network disappears,
- the supply network is disturbed.
Inverter (3) Transforms the direct voltage from the rectifier-charger or
storage battery into alternating voltage with more severe
tolerances than those of the network (supplies an
alternating current close to the theoretical sine curve).
Static contactor (4) Switches over the load supply from the inverter to network
2 (standby), and vice versa, without interruption (no cut
due to mechanical switching device changeover time - the
switchover is carried out using electronic components in a
time < 1 ms).
This switchover is performed if the inverter stops working
for one of the following reasons:
- switched off,
- overload beyond the limiting capacities of the inverter,
- internal anomaly.
Manual by-pass (5) Manual switch which allows the user to be fed by network
2 (standby), while maintenance is being carried out.
Manual switches
Battery circuit-
breakers
(6) (7) (8) (9) Provides insulation of the different parts when
maintenance is being carried out
Tableau 1-1: function of different devices making up an uninterruptible power supply system
31. 55
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
network incoming feeder(s)
The terms network 1 and network 2 designate two independent incoming feeders on the same
network:
- network 1 (or mains) designates the incoming feeder usually supplying the rectifier-charger,
- network 2 (or standby) is said to be a back-up feeder.
The inverter's frequency and phase are synchronised with network 2. Thus, the static contactor
can instantaneously switch the power supply to network 2 (in less than 1 ms).
The connection of a UPS system to a second independent network is recommended since it
increases the reliability of the system. It is nevertheless possible to have only one common
incoming feeder.
The choice of an uninterruptible power supply structure depends on the quality of networks 1
and 2, the use and the availability required. The manufacturer must provide the designer with
sufficient elements for him to choose the most suitable structure. The following examples show
the most common structures.
example 1: LV switchboard backed up by an inverter, with a generator to eliminate the
problem of the limited autonomy of the battery (usually about 15 mn) (see fig. 1-30)
MV
LV
G
non priority circuits
~
_ ~
_
filter
NC NO
NCNC
Figure 1-30: LV switchboard backed up by an inverter
The filter allows harmonic currents travelling up the supply network to be reduced.
32. 56
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 2: LV switchboard backed up by 2 inverters in parallel with no redundancy
(voir fig. 1-31)
MV
LV
G
non priority circuits
~
_ ~
_
source
network 2
priority
circuits
P
P
2
~
_ ~
_
P
2
network 1
NC NO
NC NC
filter
filter
Figure 1-31: LV switchboard backed up by 2 inverters in parallel with no redundancy
This configuration only allows an overall power capacity above that of a single rectifier/inverter
unit.
The power P to be supplied is also divided between the 2 inverters.
A fault in one of the units leads to the load being switched to network 2 without interruption,
except if the network is beyond its tolerance level.
33. 57
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 3: LV switchboard backed up by 3 inverters one of which is actively redundant
(see fig. 1-32)
MV
LV
G
non priority circuits
~
_ ~
_
source
priority
circuits
P
P
2
~
_ ~
_
P
2
~
_ ~
_
P
2
NC NO
NC NC
filter
filter
filter
Figure 1-32: LV switchboard backed up by 3 inverters one of which is actively redundant
Let P be the maximum load rating of the priority circuit.
Each inverter has a rated power of
P
2
, which means that when one inverter breaks down, the
other two inverters provide the total load power supply.
This is referred to as a parallel-connected unit with 1/3 active redundancy.
34. 58
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction , either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 4: LV switchboard backed up by 3 inverters one of which is on standby
redundancy (see fig. 1-33)
MV
LV
G
non priority circuits
source
priority
circuits
~
_ ~
_
~
_ ~
_
~
_
3
1
2
network 2
network 1
1
2
~
_
priority
circuits
3
NC
NO
NC
NC
Figure 1-33: LV switchboard backed up by 3 inverters one of which is on standby redundancy
Inverter 3 is not charged, it is on standby ready to back up inverters 1 or 2 .
There is no power cut during switchover due to static contactors and .
Static contactor provides back-up via network 2 in case there is a failure on network 1, or
the 2 inverters break down.
This is referred to as a parallel-connected unit with standby redundancy.
35. 60
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.7. Industrial networks with internal production
example (see fig. 1-34) :
Network structure:
- MV consumer substation
- the main MV switchboard is fed by the internal production station
- some MV outgoing feeders are fed by the utility and cannot be backed up by the internal
production station
- an MV loop system and some outgoing feeders are fed during normal operation by the
internal production station. If the production station breaks down, this loop system and its
outgoing feeders can be fed by the utility.
36. 61
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
37. 62
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
1.8. Examples of standard networks
example 1 (see fig. 1-35)
Network structure:
- MV consumer substation in a ring main system with two incoming feeders
- main low voltage switchboard backed up by a generator
- a priority switchboard fed by an uninterruptible power supply
- the low voltage network is the arborescent radial type. The secondary switchboard and
terminal boxes are fed by a single source.
38. 63
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
incoming feeders from utility
m LV meter
main LV switchboard
UPS
priority switchboard
secondary LV
switchboard
terminal box
G
MV
LV
terminal box
MV consumer substation
Figure 1-35: example 1
39. 64
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 2 (see fig. 1-36)
Network structure:
- MV consumer substation
- the main MV switchboard can be backed up by a generator set and it feeds 3 transformers
- an earthing transformer allows impedance earthing of the neutral when the network is fed
by generators
- the main low voltage switchboards MLVS1, MLVS2 and MLVS3 are independent and each
one has an outgoing feeder to an uninterruptible power supply feeding a priority circuit
- the low voltage network is the arborescent radial type. The motor control centres and
terminal boxes are fed by a single source.
40. 65
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
Figure 1-36: example 2
41. 66
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 3 (see fig. 1-37)
Network structure:
- MV consumer substation
- the main MV switchboard can be backed up by a generator set and it feeds 2 MV/LV
transformers
- an earthing transformer allows impedance earthing of the neutral when the network is fed
by generators
- the main low voltage switchboard has a dual power supply with coupler
- each bus section of the main low voltage switchboard has a UPS system feeding a priority
circuit
- the secondary switchboards, terminal boxes and motor control centres are fed by a single
source
42. 67
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
Figure 1-37: example 3
43. 68
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 4 (see fig. 1-38)
Network structure:
- MV consumer substation
- the main MV switchboard can be backed up by a generator set. It feeds two MV/LV
transformers in a single line supply system, 4 MV secondary switchboards in a loop system
and a secondary MV switchboard in a single line supply system
- the low voltage network is the arborescent radial type
44. 69
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
45. 70
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 5 (see fig. 1-39)
Network structure:
- MV consumer substation.
- two MV ratings: 20 kV and 6 kV.
- the main MV switchboard fed in 20 kV can be backed up by a set of 4 generators.
It feeds:
. an MV 20 kV network in a loop system comprising 3 secondary switchboards MV4, MV5
and MV6
. two 20 kV/6kV transormers in a single line supply system
- an earthing transformer allows impedance earthing of the neutral when the network is fed
by generators
- the MV main switchboard is made up 2 bus sections fed in 6 kV by 2 sources with coupler.
It feeds 3 MV secondary switchboards and two 6 kV/LV transformers in a single line supply
system.
- the secondary switchboard MV2 is fed by 2 sources with coupler and is made up of 2 bus
sections.
It feeds two 6 kV motors and two 6kV/LV transformers in a single line supply system.
- the secondary switchboards MV1 and MV3 are fed by a single source.
Each feeds a 6 kV/LV transformer and a 6 kV motor.
- the main low voltage switchboard MLVS1 can be backed up by a generator.
- the main low voltage switchboard MLVS2 is fed by 2 sources with coupler.
- the main low voltage switchboard MLVS3 is fed by a single source.
- the motor control centres 1 and 3 are fed by a single source.
- the motor control centre 2 is fed by 2 sources with no coupler.
46. 71
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
incoming feeders
from utility
main MV switchboard : U = 20 kV
MV MV
MVMV
VT
main MV switchboard : U = 6 kV
MV MV
LV LV
MLVS A MLVS B
secondary MV 1
switchboard
secondary MV 2
switchboard
secondary MV 3
switchboard
MV MV MV MV
LV LV LV LV
M M M M
G
MLVS 1
MLVS 2
MLSV 3
motor
control
centre 1
motor
control
centre 2
motor
control
centre 3
M M M M M M
MV network in a loop system : U = 20 kV
secondary MV 4
switchboard
secondary MV 5
switchboard
secondary MV 6
switchboard
UPS
MV
LV
MV
LVLVLV
MVMVMV MV
LVLV
G
4 generators
G G
MV MV MV
LV LV LV
G
LV
MV
UPS
earthing
transformer
Figure 1-39: example 5
47. 72
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE
example 6 (see fig. 1-40)
Network structure:
- HV consumer substation fed in 90 kV by 2 sources with no coupler (isolators ISO1 and
ISO2 cannot operate when loaded and are in closed position during normal operation).
- the central HV/MV transformer is used as back-up. The transformers can be connected on
the MV side via the circuit-breakers (the on-load tap changers allow the currents supplied by
each transformer to be balanced).
- two MV ratings: 20 kV and 6 kV.
- the main MV switchboard is fed in 20 kV by 3 sources with coupler. It is made up of 3 bus
sections.
- the secondary switchboards MV1, MV2 and MV3 are fed in 6 kV by 2 sources
(transformers) with coupler coming from 2 different busbars.
- the main low voltage switchboards MLVS1, MLVS2, MLVS3 and MLVS4 are fed by 2
sources with coupler.
- the motor control centres 1, 2, 3, and 4 are fed by 2 sources with no coupler.
48. 73
Publication, traduction et reproduction totales ou partielles de ce document sont rigoureusement interdites sauf autorisation écrite de nos services.
The publication, translation and reproduction, either wholly or partly, of this document are not allowed without our written consent.
Industrial electrical network design guide T & D 6 883 427/AE