Pdf gas insulated switchgear gis when coupled with short cables complicates insulation coordination practice particularly regarding fast. We will further analyze whether these overvoltages exceed the lightning impulse withstand level liwl of the cable and whether insulation coordination measures are necessary. Digsilent pacific powerfactory users conference 2011 4 network component models. In its simplest form, insulation coordination is the selection of insulation strength. Guide to power system selective coordination 600v and below. Look at the condition of the exposed cable jacket and insulation when performing a visual inspection on low voltage wire and cable. Insulation coordination in power system electrical4u. Surge arresters are applied in both ends of cable to fulfill the insulation coordination. Cyme power engineering software low voltage cable sizing. Insulation values above this level for the lines and equipment in the system must be so coordinated that specific protective devices operate satisfactorily below that minimum level. Fiberglass fiberglass can be used in extreme temperatures up to 482c. Pdf insulation coordination study of 275kv ais substation in. Cable selection and coordination with protective devices feeders. In 2012, ree together with lcoef2i2 studied the state of the grounding system of one hundred and fifty eight cable circuits of 220 and 400 kv in order to assure the insulation coordination of the.
In a few more words, insulation coordination is a series of steps used to select the dielectric strength of equipment in relation to the operating voltages and transient overvoltages which can appear on the system for which the equipment is intended. This is defined as the voltage which produces the loss of dielectric strength of an insulation. Insulation coordination studies in pscademtdc switching. Due to the coronavirus outbreak, we are happy to announce that our basic training insulation coordination analysis with emtp, has been converted to a 3day etraining. If you are choosing lower insulation level, pay close attention to the ratings of surge arrester and its install location. Apr 28, 2017 webinar on insulation coordination studies in pscad switching studies aired april 21, 2017. Influence of underground cable insulation parameters on. Insulation coordination free download as powerpoint presentation. Dec 14, 2016 for the love of physics walter lewin may 16, 2011 duration. In order to identify the cable stresses closer to reality the electric field distribution is to be obtained and then the elec ric transients liable to be encountered by that cable in. Zinc oxide overvoltage control and insulation coordination. The current carrying capacity of a cable is the maximum current that can flow continuously through a cable without damaging the cable s insulation and.
Insulated wire or cable consists of nonconductive material or some other kind of material that is resistant to an electric current. Insulation coordination studies to compare the overvoltages likely to occur in the grid with the withstand level of shield break joints. Cable management software electro insulation corporation. The dielectric strength of insulation for surges having nonstandard waveshapes is assessed by comparison to the dielectric strength as provided by standard chopped wave tests. The cable damage curve represents the maximum current that can flow through a cable for a given time without permanent damage to the insulation. Steps in the determination of insulation coordination determination of live insulation selection of bil and insulation levels of other equipment selection of lightning arrestors. Five key factors to the correct cable selection and. Depending upon the formulation the rated temperature may vary from 55 c to 105 c.
Study to determine the basic insulation level requirements. The voltage which has to be applied to a test object under specified conditions in a. Software like netdoc will help find and troubleshoot issues within a physical network. These include onecore, threecore and threecore with ground conductor with all the nominal and cable construction data available for the calculations. Other installations, such as buried and aerial, have different installation parameters. The maximum amplitude of overvoltages inside the cable is surveyed which should be of great concerns in. The paper deals with electrical transients, studying the effect of transient parameters on insulation coordination of shielded and unshielded power cables. Efficient discharge of over voltages due to lighting strike. This data is not readily available for the left end of the curve, but the data on the right side is in every arrester cut sheet and this is the part that is used for ic. Due to this new format, only 15 seats will be available, please register quickly. Using emtp package emtprv from powersys, insulation coordination study for lightning and switching over voltage performance is being carried out adopting the following methodology. A very flexible coating of an insulator is often applied to electric wire and cable, this is called insulated wire. Insulation coordination in power system was introduced to arrange the electrical insulation levels of different components in the electrical power system including transmission network, in such a manner, that the failure of insulator, if occurs, confindes to the place where it would result in the least danmage of the system.
Overvoltages and insulation coordination on transmission networks. Netdoc cable management software allows you to easily document your cable infrastructure including connections between your horizontal and backbone cables, hardware. Insulation levels wire wisdom anixter wire and cable. Some non time domain software is available for transmission line studies. For the love of physics walter lewin may 16, 2011 duration. Insulation coordination measures taken to coordinate the level of insulation in electrical equipment with. Its a function of the insulation type and conductor size. Cable insulation is used to provide electrical separation between conductors of a cable. The two most common levels are 100 percent and 3 percent. During recent years, there has been some consolidation in the types of insulation used.
Device coordination getting started with etap star youtube. Insulation coordination ic is the correlation of the insulation of various equipments to be protected transfor. Atpdraw is the time domain based transient software. Its normally not a limiting factor in most coordination applications, since the fault should be cleared well before the damage curve is reached. The cyme software includes a comprehensive cable library that comprises a large number of low voltage cables from various manufacturers. Impedance and voltage drop to iec 60909 and cenelec clctr 50480. Guide to power system selective coordination 600v and below document number 0100db0603 2. Electrical insulation is the absence of electrical conduction. This allows electrons to gain energy and thereby move through a conductor such as a metal. Polyvinyl chloride pvc, sometimes referred to as vinyl or polyvinyl chloride, consists of three types of vinyl compounds standard, semirigid and irradiated. Jul 25, 2018 insulation coordination in power system was introduced to arrange the electrical insulation levels of different components in the electrical power system including transmission network, in such a manner, that the failure of insulator, if occurs, confindes to the place where it would result in the least danmage of the system. It surrounds and protects the wire and cable inside. Introduction with the inclusion of new language in the 2005 national electrical code nec, the requirements for selective coordination of electrical power systems are, at present, more stringent than. Insulation coordination electrical substation insulator.
Selective coordination study recommended procedures. Power cable installation guide cables installed into conduits or trays have installation parameters such as maximum pulling tensions, sidewall pressure, clearance, and jamming, which must be considered. Pdf guide to sheath bonding design, in distribution and. Thermoplastic thermoplastic compounds are materials that go soft when heated and harden when cooled. Device coordination getting started with etap star duration.
Pdf points to consider regarding the insulation coordination of gis. Power substation design calculations a checklist of 18. Webinar on insulation coordination studies in pscad switching studies aired april 21, 2017. If no such states are available, the material is an insulator. The objective of this training is to give to beginner participants a good first handson experience on emtp and an overview of the emtp capabilities. Typical dielectric constant values can vary from 2. Ul 840 standard for insulation coordination including. General of seri es devices from the load to the source ar e where there are two or more series protective devices between the fault po int and the power supply, these devices must be coordinated to insure that. The selection of wirecable insulation material and jacketing compound are critical to the successful use of the wire or cable in its. As the insulation thickness changes, so must the range of the cable accessory cable insulation. Influence of transient parameters on insulation co. Pvc polyvinyl chloride is the most commonly used thermoplastic insulator for cables. In any insulation coordination study from the simple marginofprotection calculation to a complex transient analysis using software, the data from this curve must be used.
This wirecable insulation material is moisture and chemical resistant. Transformers obtain the following data for protection and coordination infor. Cable damage curves vs coordination electric power. The selection of wirecable insulation material and jacketing compound are critical to the successful use of the wire or cable in its application.
In this section we will present and analyze in detail the overvoltage stresses experienced by the insulation layers of the cable resulting from lightning strikes. The rules for the atmospheric correction of withstand voltages for external insulations are specified in ieee std 41995. The minimum level is known as the basic insulation level bil that must be that of all of the components of a system. Cable insulation materials the following materials are typically used for cable insulation.
Galaxy is a leading manufacturer and supplier of standardstock and custom wire and cable with a wide variety of material choices for the jacket and insulation. Power systems transients and insulation coordination course london. However, wires that touch each other produce cross connections, short circuits, and fire hazards. Insulation levels cable insulation is designed to withstand the voltage stresses a cable will experience over its expected lifetime. Insulation coordination principles limitation of switching surges is essential highly efficient arresters installation of additional arresters on 800 kv dc bus and converter bus between transformer and valve arresters installed very close to object no distance effects. There are varieties of wires and cables as well as wire and cable insulations. Power systems transients and insulation coordination course. It was assumed that lightning overvoltages would be introduced into the cgit system due to lightning strokes. Insulation coordination study of 275kv ais substation in malaysia. When sizing cables for nonmotor loads, the upstream protective device fuse or circuit breaker is typically selected to also protect the cable against damage from thermal overload. Selective coordination study recommended procedures 14 the following steps are recommended when conducting a selective coordination study. Current capacity to bs 7671, era 6930 and iec 60502. Daffodil crm possesses a set of useful features like search option, import facility, task pop up, integrated email campaigns, customizable views, powerful. This post provides some information on the more commonly used cable.
Wires sometimes dont use an insulating coating, just air, since a solid e. Using software for cable management is a great way to record your cable network. Assessment of overvoltage and insulation coordination in. Pdf influence of underground cable insulation parameters on. Silicone is heat resistant, flame retardant and can be used in temperatures up to 180c. Outcome of insulation coordination study choose standardized bil rating basic lightning impulse insulation level for the substation from ieee. Daffodil crm is an open source customer relationship management software that enables seamless coordination between sales, marketing, customer service, field support and other functions that handle customer contact for an enterprise. Overvoltages and insulation coordination in mv and hv. Powertech labs conducts studies to achieve costeffective station equipment insulation requirements. Insulation coordination in power system was introduced to arrange the electrical insulation levels of different components in the electrical. During the historical development of cables, numerous types of insulation have been employed. This deals with lightning and switching overvoltages ovs in a power system and rarely with power frequency 50 or 60 hz faults. Oneline diagram obtain the electrical system oneline diagram that identifies important system components, as given below. Inspect compressionapplied connections by verifying that the connector is properly rated for the installed cable size and has the proper indentations.