Grounding is used to get a reference point to measure voltage, to get a common return path for current and to physical connection of body. Environmental and structural condition monitoring and protection is the use of the control room in a substation. Earthing practices electrical substation transformer. Control desks for generating stations, substations. Introduction to substation earthing grid in high and medium voltage 1 air insulated substations ais the electromagnetic field, which causes are the static charges of bare cable and conductors and by the atmospheric conditions surges, induce voltages at nolive parts of the installation that create potential differences between metallic parts and ground and also between different points of the ground. Design of earthing system for 400 kv ac substation a case. Operation and maintenance of a gas insulated substation. The relays, protection and control panels are installed in the controlled room. In order to have uniform interconnection, a mat or grid or earthing conductor is formed inside the soil. E substation standards pcb control cabinets shielded cable grounding 67. Ieee std 1421991, also known as the ieee green book, covers. Earthing system station earthing system includes earth mat and earth electrodes placed below ground level function earthing system is to provide low.
The checklists are in pdf format and can be completed electronically or printed and used as hard copy. B substation standards typical power circuit breaker wiring diagram sh 1 of 3 69. General specification for the civil engineering and building design and construction of 275kv and 400kv substations. Between the generating station and consumer, electric power may flow through several substations at different voltage levels. Ieee std 6651995, ieee guide for generating station grounding. A substation is assembly of large no of electrical equipment.
Design of earthing system for extra high voltage ac power. Surge arrestors would protect the substation equipment from lightning and switching surges. Notify the control room as to the reason for being there and the. Electrical inspection checklists this pdf contains 77 electrical inspection checklists taken from the 2014 electrical inspection manual with checklists.
Control desks have been designed and manufactured by acrastyle for almost 40 years. Electric substation design implementations through cymgrd this book is to discuss developmental procedure of an effective substation earthing system model to ensure that step and touch potentials. Specifically, a control room exists to make sure that the wellbeing of equipment. However as with typical substation earthing analysis. Use of log book the trainee completing this log shall be under the guidance of a mentor. Before individual units are handled they shall be shortcircuited between all terminals and the case.
Substation earthing system design optimisation through the. Ieee std 1421991, also known as the ieee green book, covers some of the practical. Maybe fault, tripping, 33kv breakdown and burning of cables 2. The earthing switch is usually connected between the line conductor and earth and is mounted on the frame of isolator. Portable relay rooms and control rooms for substations. This is a guideline to design the earthing system of ac substation based on ieee 80 standard. With its long experience of power system protection and control design, it is not surprising that many of the control desks in large substations, generating stations and central control rooms have been designed and built by acrastyle. The collector substation can also provide power factor correction if it is needed, metering and control of the wind farm. Operation of a gis substation involves the same principles as operati ng an air insulated substation ais even though the different active elements are physically arranged differently. Perform high voltage switching, earthing and issue electrical access authorities on.
Corrosion can affect integrated circuits, electronic circuit boards, control relays, transformers, motor control systems, control device systems and finally every type of electrical or electronic equipment. Acrastyles expertise in power system protection design and manufacturing enables us to provide portable relay rooms and control rooms. Earthing overview preamble though there is legal binding on electric utilities to measure the values of earth electrode resistance and to. Earthing can be made with charcoal, salt, and water. Handbook on earthing system for power supply installation.
At indoor gis substations access to the control room shall not be through. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. The earthing system also ensures that no thermal or. The control room at the iso new england is where power in the region is dispatched and the grid monitored for reliability. Design of earthing system for 400 kv ac substation. Design of earthing system for 400 kv ac substation international.
The substation involves many earthing through individual electrodes. Overhead earthwire shielding against lightening strokes. Earthing system in a sub station comprises of earth mat or grid, earth electrode. National grid substations technical specification ngts 2.
The first step in designing a power substation is to design an earthing and bonding system go to content earthing and bonding. After common and expected controls are implemented, is the residual risk above a level. What is the use of the control room in a substation answers. The relays were housed in panels in the control room and ring main units. General specification for the civil engineering and. Dc earth fault in dc control system is very usual which occurs in substation, power plant or anywhere in control circuit where dc supply is used for control purpose. The document describes safe work practices for the control of.
Specification for erection, testing and commissioning of. Voltaic pv power plant earthing design services in 2015 1. Safe work practices on high voltage substation apparatus. Xr low no tr in sub only hv switching station xr 2. An electrical substation is a part of the electrical installation that includes the terminations of the transmission or distribution lines and switchgear, and which may also include transformers the substation also typically includes all the necessary devices for control and protection. These allow the customer to quickly integrate the protection system on site with plugandplay connectivity. The codes of practice, technical reference books, handbooks contain a. The indicative layout plan and single line diagram of the substation is enclosed herewith. We often encounter sites which have separate hv and lv earths. The manual is applicable for all substation projects regardless of internalexternal design delivery mode. Distribution substations michigan technological university. Ieee guide for safety in ac substation grounding ieee std.
In the uk, it is often assumed that a separation of 10m between earths will prevent the transfer of potentials between the two electrical earthing systems e. Electrical software institute for engineering training. Ieee guide for safety in ac substation grounding ieee std 802000. The various circuit breakers, tap changers and other devices are controlled by corresponding control relay panels. Earth mat earth mat design earth grid what is earth. These panels along with pc aids in automatic operation of various circuit breakers, tap changers, autoreclosers, sectionalizing switches and other devices during faults and abnormal conditions. The substation design manual is not intended to replace asset management standards, but rather. This webinar discusses the basic configuration of a substation as well as the key players involved with operations and control of transmission and distribution circuits. Khimtibarhabiselapsiphedi 400 kv substation project.
Rapid on site integration of power system protection. Usually, cu or al used for earthing but due to the cost of cu is high we. Substations involves many earthlings through individual electrodes, which will have fairly high resistance. Earthing works bidder understand that there is no earth work is required in the main earthing grid for the extension. Design study for 3311 kv substation, distribution and. Subtransmission and distribution apparatus within zone substations.
Pdf guideline for earthing of substation researchgate. The control method varies, but it largely comes down to these two central concepts. The relay and protection panels and control panels are installed in the control room. This corrosive effect develops mainly in certain parts which are particularly sensitive. The various supervision, control and protection functions are performed in the substation control room. Design of earthing grounding system in a substation grid. Only additional gis bays will be connected with earthing riser.
Earthing and bonding at secondary substations 1 scope this section of the distribution construction manual lays down the standard for earthing and bonding of plant and apparatus at secondary substations to comply with regulations. Endorsed to perform supervision for the earthing of metal clad switchgear in zone substations. Collector substations also exist where multiple thermal or hydroelectric power plants of. This document sets out a range of hazardous situations, the controls safeguards to be implemented and. This manual outlines the standard energex distribution earthing practices for low voltage and 11kv systems. A substation is a part of an electrical generation, transmission, and distribution system. Substation equipment such as circuitbeakers, isolators, earthing switches, surge arresters, cts, vts, neutral grounding equipment. A substation standards control cable color code identification 68. This paper presents the design of earthing system for 400 kv substation and calculation of. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. The function of an earthing and bonding system is to provide an earthing system connection to which transformer neutrals or earthing impedances may be connected in order to pass the maximum fault current.10 406 975 833 1360 997 965 870 417 610 191 97 146 1433 607 313 885 1345 80 902 756 973 200 960 1017 1190 1413 1182 306 820 1243 132 1065 203 1131 658 97 1306 455 2 1419 420 537 1205 1307 503