Uhvdc system overvoltage and insulation coordination. Insulation coordination for converter station of 800kv uhvdc project from jinping to sunan j. Generally, for existing insulation coordination studies the power system has been modeled either by. Assessment of overvoltage and insulation coordination in. Apply the principles of lightning protection to other industries, such as industrial, chemical, renewable energy, nuclear, and oil and gas. Overvoltages and insulation coordination training course industry need this course provides engineers with a fundamental understanding of transient phenomena common to electric power systems. The method and the technologies to control the overvoltage and the impact of the size of the resistor to the overall insulation coordination were also. A list of organizations represented on this committee can be obtained on request to its secretary. Introduction lightning overvoltages on hv transmission lines. Efficient discharge of over voltages due to lighting strike. Also resulting from this analysis, a methodology for compacting. Interaction phenomena between parallel ac and dc overhead lines.
Electrical safety power quality analysis risk mitigation. Assessment of overvoltage and insulation coordination in mixed hvdc transmission lines exposed to lightning strikes article pdf available in energies 1221. For apparatus, acceptable failure rates ra due to overvoltages are in the range of 0. Although simple in concept, involving comparisons between maximum network overvoltages and minimum insulation breakdown voltages, in practice the process is complex. Standards and insulation hv insulation coordination p. 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. Im directional distance relay and rx diagram lightning, switching surge phenomena and breaker switching overvoltage phenomena insulation coordination harmonics and waveform distortion power. Electrical safety, power quality, electrical analysis and osha and nfpa 70e training conducted by qualified engineers who perform thousands of power systems, power quality and arc flash analyses each year, as well as sit on ieee and other industry boards to help develop safety standards. Mar 17, 2011 overvoltage is classified as a longduration voltage variation phenomena, which is one of the general categories of power quality problems mentioned in the second post of the power quality basics series of this site. Power system dynamics with computerbased modeling and. An overview on overvoltage phenomena in power systems. Pdf assessment of overvoltage and insulation coordination in. Simulation of interaction phenomena between parallel ac and dc overhead lines.
Thus, this work seeks to model a lightning induced over voltage transient. Insulation coordination free download as powerpoint presentation. Iec standard 60071 classifies these over voltages as. In some applications, the subject of overvoltage categories may result in a need to change from a umg 604 with 300 v catiii to a umg 508 with the overvoltage category 600 v catiii, i. Abstractinsulation coordination methodologies are analyzed and a program built by the author is presented, which executes the insulation coordination algorithm proposed by the standards of the international electrotechnical comission iec.
Overvoltages and insulation coordination in mv and hv studiecd. Overvoltage and insulation coordination of overhead lines in. Calculation of lightning overvoltage failure rates for a gas. 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. This chapter provides an example of lightning insulation coordination. Overvoltages and insulation coordination in mv and hv. Surge arresters play an important role in reaching this goal. Lightning insulation coordination is based on statistical approaches. Power consulting overvoltage protection and insulation. Pdf an overview on overvoltage phenomena in power systems.
Digsilent pacific powerfactory users conference 2011 4 network component models. The lightning strikes can not only result in flashover of overhead line ohl insulators but can enter the cable and permanently damage its insulation if adequate insulation coordination measures are not taken. The first step in the insulation coordination is the determination of the representative over voltages in the system urp to which the electrical circuit is subjected to, under various operating conditions and switching phenomena. Study on overvoltage and insulation coordination of dc filter. Insulation coordination, different types of electrical stress working voltage, lightning and switching over voltages and the behavior of different insulation systems in action of these stresses, represent the central part of this course. Calculation of the strength the study calculation of dielectric withstand characteristics of the insulation when submitted to. Insulation coordination aims at minimizing prob ability of an insulation failures by developing overvoltage protection concepts taking into account the specific system configuration, but also economical aspects. Overvoltage on unfaulted phase during typical range of magnitude and duration of power system temporary overvoltages. Lightning surges fastfront overvoltage switching surges slowfront overvoltage temporary. As such, a uhvdc transmission system has more operation modes than conventional dc transmission projects see chapter 3.
In cooperation with graz university of technology university of zagreb university of sarajevo 3 days training grazaustria 1820 october 2010 use of the emtprv software for insulation coordination studies. Insulation coordination ic is the correlation of the insulation of various equipments to be protected transfor. Crossreferences the british standards which implement international or european publications referred to in this document may be found in the bsi catalogue. Modeling breakers for studying transient recovery voltage. If the overvoltage inside the cable exceeds the lightning impulse withstand level.
However, as uhv system lines are characterized by a larger transmission capacity, longer transmission distances, and large reactive power the reactive power per 100 km of kv lines reaches up to about 530 mvar such that. This practice is where the characteristics of the system, insulation of all forms, and arresters of all forms cross paths. A supporting routine available in most transients programs allows users to. In addition, the steadystate operating voltage on electrical equipment at converter stations varies with the engineering design and operation mode. This deals with lightning and switching overvoltages ovs in a power system and rarely with power frequency 50 or 60 hz faults. Overvoltages and insulation coordination etf eeo pki 4865. When any over voltage appears in the electrical power system, then there may be a chance of failure of its insulation system. All simulations have been conducted using matlab and atpemtp software.
Provide costeffective solutions to reduce lightning overvoltage in power systems. Ground potential rise at the pv plant must be considered be. Understand the key principles and concepts regarding lightning protection and transient overvoltage. This allows to correlate the electrical stress caused by lightning and the electrical strength of the insulations, both having probabilistic nature. In this work, we have analyzed the factors that affect the level of overvoltage inside the cable by simulating a fast front model in pscad. The material is especially suited for those who simulate transients with tools such as emtp, those who analyze waveforms from. Overvoltages 1 2 3 4 5 6 106 104 102 100 102 104 t s u p.
Coordination is an integral part of the design process, giving criteria that are satisfied through insulation design and through overvoltage control and protection. Introduction lightning insulation coordination insulation coordination is required to ensure equipments insulation shall withstand voltage stress caused by lightning strike. Insulation coordination of overhead transmission lines. Insulation coordination has become a well developed engineering practice. New method of protection against lightning overvoltages for high. Part 2, characteristics as machinery steadystate, transient, dynamic stability induction generator and motor induction machine.
Then the insulation coordination for overhead lines was conducted according to the overvoltage level. Lightning protection and transient overvoltage calgary. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. The selection of the insulation strength of equipment in relation to the voltages, which can appear on the system for. Insulation coordination encompasses all aspects of the power system and attempts to ensure uninterrupted supply of power under the worst overvoltage and environmental conditions. The international standard iec600712 insulation coordination third edition 1996 states the following. Insulation coordination and voltage transients for industrial. Uhv ac system overvoltage and insulation coordination. Insulation coordination in power system electrical4u. Pdf assessment of overvoltage and insulation coordination. In terms of overvoltage and insulation coordination, a uhv system is similar to an extrahighvoltage ehv system. Sudden changes in electrical network structure give rise to transient phenomena frequently resulting in the creation of an overvoltage or of a high frequency wave. Power system overvoltage, surge arrester, insulation coordination. Overvoltages and insulation coordination coursewebs.
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