energies Article Carlos A. Platero 1, * ID, Jesús Serrano 1, Máximo López-Toledo 1 and Ricardo Granizo 2 ID

Transcription

1 energies Article Influence High-Speed Tra Power Consumption Arc Resistances on a Novel Ground Location Method for 2 25 kv Railway Power Supply Systems Carlos A. Platero 1, * ID, Jesús Serrano 1, Máximo López-Toledo 1 Ricardo Granizo 2 ID 1 Department Electrical Engeerg, ETS Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutierrez Abascal, 2, 286 Madrid, Spa; jserranoalv@hotmail.com (J.S.); maximo.lopez@upm.es (M.L.-T.) 2 Department Electrical Engeerg, ETS Ingeniería y Diseño Industrial, Universidad Politécnica de Madrid, C/Ronda de Valencia, 3, 2812 Madrid, Spa; ricardo.granizo@upm.es * Correspondence: carlosantonio.platero@upm.es; Tel.: ; Fax: Received: 17 May 218; Accepted: 15 June 218; Published: 19 June 218 Abstract: The 2 25 kv power supply system is most frequently used traction rail system to provide huge power needed by high-speed tras. However, locatg this power supply system is more complicated than or configurations electrical railway power supply due to stallation throughout le section. In previous papers, authors have described a location method with an significant stallation cost. The method, moreover, location discrimate wher is located a positive conductor or a negative conductor. The current high-speed tra fluences accuracy location. An additional factor which fluences location method is existence an arc resistance positive or negative conductor. In this paper, fluence high-speed tra currents arc resistances are analysed to evaluate error location method. The major conclusion paper is that location method has an acceptable precision even takg to consideration high-speed tra current arc resistance. The validation method has been performed by laboratory tests computer simulations with satisfactory results. Keywords: electrical protection; s; location; railways power system; 2 25 kv 1. Introduction High-speed tras are one more effective faster modes transport medium big cities with distances range 6 km. To supply high power dem se tras, a 2 25 kv AC power supply system is used, due to advantages providg high power with lower currents fewer traction substations on le [1]. In a 2 25 kv supply system, power le is supplied by some traction substations (TSs). Each substation feeds two sections, one each direction, each section is formed by some subsections delimited by (ATs). At end each section, a fal autotransformer (SATS) is stalled. The 2 25 kv power supply systems have three conductors. The positive conductor (usually named as catenary) is at 25 kv AC voltage with a positive polarity from. The negative voltage conductor (usually named as feeder) is at 25 kv AC voltage with a negative polarity from. Fally, third conductor is rail, which is ed [2]. 1 displays Energies 218, 11, 161; doi:1.339/en

2 Energies 218, 11, Energies 218, 11, x FOR PEER REVIEW displays simplified diagram simplified adiagram 2 25 kv power a 2 25 system kv power section system comprisg section three comprisg subsections three (A, subsections B, C), delimited (A, B, byc), three delimited by three (ATS 1, ATS 2, SATS). (ATS The 1, ATS current 2, distribution SATS). isthe represented current when distribution a trais isrepresented located when midpot a tra is subsection located B. midpot subsection B Simplified Simplified scheme scheme a kV kvrail railpower system. system. Traction railway power supply systems must be protected by electrical relays, which ensure Traction railway power supply systems must be protected by electrical relays, which ensure y y will work effectively reliably. Also, due to physical configuration (proximity to bushes will work effectively reliably. Also, due to physical configuration (proximity to bushes electric le, slippg pantograph on catenary), railway power supply systems have electric le, slippg pantograph on catenary), railway power supply systems have larger number s than or electrical stallations [3]. It is necessary to detect a larger number s than or electrical stallations [3]. It is necessary to detect locate s a reliable fast way order to repair m as fast as possible without locate s a reliable fast way order to repair m as fast as possible without large large terruptions railway service. However, locatg s se 2 25 kv terruptions railway service. However, locatg s se 2 25 kv systems is systems is more difficult than or AC traction rail systems, which use impedance method to more difficult than or AC traction rail systems, which use impedance method to measure measure length from substation to position [4]. length from substation to position [4]. The impedance/distance ratio is not lear a 2 25 kv power supply system, so The impedance/distance ratio is not lear a 2 25 kv power supply system, so impedance impedance method cannot be used [5]. method cannot be used [5]. There are different methods based on underimpedance relays, which present advantages There are different methods based on underimpedance relays, which present advantages disadvantages. Some m are based on dividualization catenary feeder circuits disadvantages. Some m are based on dividualization catenary feeder circuits [6]. [6]. Ors use numerous underimpedance relays stalled every autotransformer Ors use numerous underimpedance relays stalled every autotransformer sectionalizg sectionalizg pot [7]. pot [7]. There are methods based on different measurements, such as current relations neutral There are methods based on different measurements, such as current relations neutral connection [8,9] or measurements made by current sensor stallations at connection [8,9] or measurements made by current sensor stallations at connections rail air cable return [1]. Or research les are connections rail air cable return [1]. Or research les are progressive wave location method [11,12], doma frequency location methods [13], progressive wave location method [11,12], doma frequency location methods [13], methods methods which compare models time doma with ors frequency doma [14]. which compare models time doma with ors frequency doma [14]. novel method identifyg subsection where A novel method identifyg subsection where has happened identifyg y conductor was presented [15]. This identification has happened identifyg y conductor was presented [15]. This identification method, method, combed with an analysis currents, allowed location combed with an analysis currents, allowed location method method presented [16] to be developed. presented [16] to be developed. There are some factors which can produce errors location, such as There are some factors which can produce errors location, such as arc arc resistance or tra circulation. resistance or tra circulation. In this paper, fluence high-speed tra currents arc resistances is analysed to In this paper, fluence high-speed tra currents arc resistances is analysed to evaluate evaluate error location method presented [16]. error location method presented [16]. This article is structured as follows: Section 2 fers a short description This article is structured as follows: Section 2 fers a short description location location method. Then, Section 3 details fluence high-speed tra power dem method. Then, Section 3 details fluence high-speed tra power dem arc arc resistance short-circuit current. Section 4 analyses computer simulations, resistance short-circuit current. Section 4 analyses computer simulations, Section 5 Section 5 analyses experimental results. Fally, Section 6 presents contributions analyses experimental results. Fally, Section 6 presents contributions article. article.

3 Energies 218, 11, Energies 218, 11, x FOR PEER REVIEW Short Short Description Description Ground Ground Location Location Method Method for for kv kv Supply Supply Systems Systems This This new new location method for kV kvrailways power power systems systems is founded is founded on on comparison angles angles currents currents voltages voltages as well as well as as module values module se values currents se when currents when happens. happens. This location method comprises three steps ( 2). 2). 2. Simplified layout location method for 2 25 kv rail power system. 2. Simplified layout location method for 2 25 kv rail power system Measurement 2.1. Measurement If a occurs, re are overcurrents adjacent. The autotransformer If a currents occurs, will re surpass are overcurrents a certa limit, adjacent location. system is started. The autotransformer currents In will this first surpass step, ait certa is necessary limit, to record location currents system is voltages started. (VC1, IA1; VC2, IA2; VC3, IA3). In this first step, Also, it is necessary phase angle to record currents m should be voltages recorded. (V C1, ; V C2, ; V C3, ). Also, phase angle m should be recorded Subsection Conductor Identification 2.2. Subsection Conductor Identification Then, subsection conductor where has occurred are recognized by analysis Then, subsection angle conductor voltages where currents haspreviously occurred are measured recognized by analysis. anglethe complete method voltages is described currents [15]. previously measured. The complete Accordg method to [15], is when described a [15]. occurs rail catenary or rail feeder, Accordg re is an to important [15], when crease a occurs current wdgs rail catenary or adjacent rail to feeder, re. is anmoreover, important crease angles current currents wdgs voltages change 9 at adjacent.. Moreover, angles currents voltages change 9 at.

4 Energies 218, 11, Energies 218, 11, x FOR PEER REVIEW presents, as an example, a diagram a 2 25 kv section with three subsections where a Energies 218, 11, 3 x presents, FOR PEER as REVIEW an example, a diagram a 2 25 kv section with three subsections 4 where 2 a rail rail catenary catenary has occurred. has occurred. The angles The angles V C2 V C3 are decreased from close to 18 to near to 9 IA2 VC2 IA3 VC3 3 are presents, decreased an from example, close to a 18 diagram to near a to kv section with three subsections where a rail catenary has occurred. The angles IA2 VC2 IA3 VC3 are decreased from close to 18 to near to Diagram a 2 25 kv power system with a catenary subsection C. 3. Diagram a 2 25 kv power system with a catenary subsection C Locator 3. Diagram a 2 25 kv power system with a catenary subsection C Locator Fally, locator is founded on a previous calculation currents 2.3. Locator Fally, locator case a is founded at on all positions a previous a section calculation [16]. currents Fally, The previous case calculations alocator is should founded at be all made on positions a considerg previous a section calculation particular [16]. data currents 2 25 kv The power previous system. calculations The case values should a autotransformer be made at all considerg positions currents, a section particular case [16]. data a 2, 25must kv power be system. stored The The values as previous look-up tables. calculations autotransformer should be currents, made considerg case particular a data, must 2 be 25 stored kv as power The system. The is located values by comparg autotransformer current currents, recorded case adjacent a, must with be look-up tables. stored values as look-up stored tables. look-up tables previously. Thereby, can be located. The is located by comparg current recorded adjacent with The One typical is located distribution by comparg autotransformer current recorded currents adjacent case a along with values section stored values is shown stored look-up look-up tables 4 as an previously. tables example. previously. Thereby, Thereby, can can be be located. located. One typical One typical distribution distribution autotransformer currents case case a a along along section section is shown is shown 7 4 as4 an as an example Current [A] Current [A] Simulated currents 2 25 kv power system with AT1, AT2, SATS for different locations. rail catenary. 4. Simulated currents 2 25 kv power system with AT1, AT2, SATS 4. Simulated currents 2 25 kv power system with AT1, AT2, SATS for different locations. rail catenary. for different locations. rail catenary.

5 Energies 218, 11, Energies 218, 11, x FOR PEER REVIEW Influence High-Speed Tra Tra Power Power Dem Resistances The The aim aim this this article is is to to analyse fluence tra tra circulation arc arc resistance on on new new location method presented [16]. [16]. As As location location method method is based is based on a comparison on a comparison calculated calculated measured currents, measured currents, circulation circulation tras or tras arc resistance or arc could resistance produce could anproduce error an error location. location. Therefore, fluence se se factors factors on on current current modules modules se se as wellas aswell on as angles on angles currents currents voltage voltage when when occurs will occurs be studied. will be studied High-Speed High-Speed Power Power Consumption Consumption a 2 a kv kv Railway Railway Power Power Supply Supply System System To To analyse analyse effect effect tra tra power power dem dem on on accuracy accuracy location location method, amethod, current a source current hassource been cluded has been cluded circuit presented circuit presented 3. The maximum 3. The power maximum dem power considered dem durg considered acceleration durg is acceleration MW. is This is represented MW. This is by represented a current (I) by a current 616 A with (I) a A power with a factor..95 power As an example, factor. As an example, 5, current source 5, is current located source midpot is located subsection midpot B, but different subsection trab, locations but different different tra locations operation pots different have operation also been pots studied. have also been studied kv kv power power supply supply section section cludg cludg a a tra. tra Resistances 2 25 kv Railway Power Supply Systems 3.2. Resistances 2 25 kv Railway Power Supply Systems The resistance is related to sulation distance current. In this paper, it is The resistance is related to sulation distance current. In this paper, it is considered that can be produced catenary sustenance pole or considered that can be produced catenary sustenance pole or feeder sustenance pole. The sulation distance (L) catenary or feeder sustenance pole. The sulation distance (L) catenary or feeder feeder sustenance post is 4 mm ( 6). sustenance post is 4 mm ( 6). Accordg to [17], different models resistance estimation have been developed by Accordg to [17], different models resistance estimation have been developed by Warrgton (1), Mason (2), Goda (3), Terzija Kogl (4), Blackburn Dom (5). Warrgton (1), Mason (2), Goda (3), Terzija Kogl (4), Blackburn Dom (5). Warrgton: Warrgton: = R = L. I 1.4 (1) Mason: R = L (2) = I (2) Goda: [ Goda: 95 R = + 5 ] = 95 I + 5 I 2 L (3) (3) Terzija Kogl: [ Terzija Kogl: R = ] = I I 2 L (4) (4) Blackburn Dom:

6 Energies 218, 11, Energies 218, 11, x FOR PEER REVIEW 6 2 Blackburn Dom: R = = L (5) (5) I where R Arc resistance (Ω) L R Arc length resistance (m) (Ω) I L RMS Arc length value (m) current (A) I RMS value current (A) These expressions have been developed thanks to numerous experimental tests different current These ranges expressions [17]. Accordg have been to developed railway geometry thanks to numerous experimental current levels, tests Mason s different model has current been ranges chosen. [17]. Accordg to railway geometry current levels, Mason s model has been The error chosen. produced by arc resistance would be higher for lower values currents. Considerg The error 25 produced A as by value arc resistance current would an arc be higher length for.4 lower m, values resistance currents. to be considered Considerg is AΩ. as An arc value resistance current.29 Ω is refore an arc length considered.4 m, simulation resistance model. to be considered is.2887 Ω. An arc resistance.29 Ω is refore considered simulation model. 6. Typical high-speed railway geometry considered for simulation. 6. Typical high-speed railway geometry considered for simulation. 4. Simulations 4. Simulations Numerous computer simulations have been performed to analyse effect high-speed Numerous computer simulations have been performed to analyse effect high-speed tra circulation resistance location. tra circulation resistance location. The circuit presented 7 was programmed Matlab (Version 216b, MathWorks, Inc., The circuit presented 7 was programmed Matlab (Version 216b, MathWorks, Inc, Natick, MA, USA). The modified nodal circuit analysis method was used [18]. The circuit was fed from Natick, MA, USA). The modified nodal circuit analysis method was used [18]. The circuit was fed one end by two 25 kv AC sources. A 1-km length was used for three subsections A, B, C. from one end by two 25 kv AC sources. A 1-km length was used for three subsections A, B, These simulations are described next subsections. C. These simulations are described next subsections.

7 circulatg section, circuit shown 7 was employed. Thanks to simulations, changes phase angle currents voltages as well as current modules have been obtaed. As stated before, current source for simulatg a tra corresponds to 616 A with a power factor.95. Additional simulations have been cluded considerg one tras at one third rated power (4.88 MW) Energies 218, 11, Equivalent 7. Equivalent circuit circuit kv kv power power supply supply section section cludg cludg a tra a tra for for simulation Simulations The mutual Influence self-impedances Tra Power employed Consumption simulation are listed Table 1. These impedances correspond to catenary feeder configuration presented 6. InEmployg order to simulate circuit shown 2 25 kv power7, system different MATLAB case asimulations were with developed, a tra circulatg with short-circuits section, circuit rail shown catenary 7 was employed. Thanks rail to simulations, feeder. The changes s phase were angle simulated along currents three subsections voltages A, B, C, cludg existence as well as one current or two modules tras have midpot been obtaed. each subsections. As stated before, current source for simulatg a tra corresponds to 616 A with a power factor.95. Additional Table simulations 1. Self have mutual been impedance cluded considerg 2 25 kv power one system. tras at one third rated power (4.88 MW) Conductor Impedance (Ω/km) Conductor Impedance (Ω/km) The mutual self-impedances employed simulation are listed Table 1. These Catenary C j.6224 Catenary feeder CF.48 + j.341 impedances correspond to catenary feeder configuration presented 6. Feeder F j.7389 Catenary rail CR j.3222 Employg Rail circuit shown R j.529 7, different Feeder rail MATLAB simulations FR.488 were + j.2988 developed, with short-circuits rail catenary rail feeder. The s were simulated Influence along Tra three Consumption subsections on A, Current-Voltage B, C, cludg Phase existence Autotransformer one or two tras Case a Ground midpot each subsections. The phase angles Table 1. Self voltages mutual impedance currents 2 25 kv power system. ATS 1, ATS 2, SATS were also analysed from simulation results. In this section, several examples have been cluded. s Conductor 8 9 Impedance show angles (Ω/km) with a tra Conductor circulatg at Impedance midpot (Ω/km) subsection A with s Catenary C catenary j.6224 Catenary feeder feeder. CF.48 + j.341 Feeder F j.7389 Catenary rail CR j.3222 Rail R j.529 Feeder rail FR j Influence Tra Consumption on Current-Voltage Phase Autotransformer Case a Ground The phase angles voltages currents ATS 1, ATS 2, SATS were also analysed from simulation results. In this section, several examples have been cluded. s 8 9 show angles with a tra circulatg at midpot subsection A with s catenary feeder.

8 Energies 218, 11, x FOR PEER REVIEW 8 2 Energies 218, 11, 161 x FOR PEER REVIEW 8 2 -V -V C1 C1 -V -V C2 C2 -V -V C3 C ATS1 15Distance[km] ATS1 Distance[km] ATS2 15Distance[km] ATS2 Distance[km] SATS 15Distance[km] SATS Distance[km] 8. Phase angles IA VC at different ATSs as a function distance from 8. IA VC to 8. substation. Phase angles considered I A Vat C at catenary different ATSs ATSs as rail a asfunction a with a tra at distance distance midpot from from to to substation. substation. considered catenary rail rail with witha a tra at midpot subsection A. subsection A. A. -V -V C1 C1 -V -V C2 C2 -V -V C3 C ATS1 15Distance[km] ATS1 Distance[km] ATS2 15Distance[km] ATS2 Distance[km] SATS 15Distance[km] SATS Distance[km] Angles I A IA V C as VC a as function a function distance distance from from to traction to substation. traction 9. Angles IA VC substation. rail feeder rail with afeeder tra as at with a function a midpot tra at midpot subsection distance from A. subsection A. to traction substation. rail feeder with a tra at midpot subsection A. Additionally, s show phase angles current voltage at at Additionally, s 1 11 show phase angles current voltage at with with two two tras tras circulatg circulatg with with s s catenary catenary first case first with two tras circulatg with s catenary first case s s feeder feeder second second case. Incase. simulation In simulation presented presented 1, case s feeder second case. In simulation presented tras 1, circulate tras circulate midpots at midpots subsections subsections A B, A B, simulations simulations presented presented 11, 1, tras circulate at midpots subsections A B, simulations presented tras 11, circulate tras atcirculate midpots at midpots subsections subsections A C. A C. 11, tras circulate at midpots subsections A C. The The second second step step location location method method is based is based on on phase shift phase shift voltage voltage The second current step case a location. Accordg method to is based simulation on results, phase shift fluence current case a. Accordg to simulation results, fluence voltage tra circulation current on case phase a angles is. very Accordg small. Only to simulation case a results, fluence tra circulation phase angles is very small. Only case a close close to to tra circulation is on re a phase slight angles difference is very from small. oretical Only decrease case a 9 when re close is to is re a slight difference from oretical decrease 9 is or re a slight difference from oretical 9 decrease 9 when re is a when re is a catenary or from oretical crease 9 catenary or from oretical do not crease 9 case a feeder. case feeder. These small deviations phase angle do not produce correct operation directional These small deviations se phase relays angle have do a not phase produce angle correct area operation range ±3. directional overcurrent relays because se relays have a phase angle trippg area range ±3 overcurrent relays because se relays have a phase angle trippg area range ±3..

9 Energies 218, 11, x FOR PEER REVIEW 9 2 Energies 218, 11, 11, 161 x FOR PEER REVIEW I -V A1 C1 -V C1 I -V A2 C2 -V C2 I -V A3 C3 -V C ATS1 Distance[km] ATS1 Distance[km] ATS2 15Distance[km] ATS2 Distance[km] SATS 15Distance[km] SATS Distance[km] 1. Angles IA VC as a function distance from to traction IA VC substation. 1. Angles rail I A catenary V C as a with function two tras at distance midpot from subsections to to A traction B, substation. rail catenary with two trasat at midpot subsectionsa A respectively. B, B, respectively. I -V A1 C1 -V C1 I -V A2 C2 -V C2 I -V A3 C3 -V C ATS1 15Distance[km] ATS1 Distance[km] ATS2 15Distance[km] ATS2 Distance[km] SATS 15Distance[km] SATS Distance[km] Angles IIA A VVC C as a function distance from to to traction 11. Angles IA VC as a function distance from to traction substation. considered rail feeder with two tras at at midpot subsections A substation. considered rail feeder with two tras at midpot subsections A C, C, respectively. C, respectively Influence Tra Tra Consumption on on Autotransformer Currents Currents Case Case a Ground a Ground Influence Tra Consumption on Autotransformer Currents Case a Ground This simulation model is similar to that shown previous subsection. Numerous simulations have been This performed, simulation but model onlyis some similar m to are that presented shown as examples previous with subsection. tra circulation Numerous This simulation model is similar to that shown previous subsection. Numerous simulations case s have been performed, catenary but only some m are feeder presented. as examples with tra simulations circulation have been performed, but only some m are presented as examples with tra In this case, case currents s catenary are represented for feeder s. along circulation In this case, case currents s catenary are represented for feeder s. section case one tra circulatg subsection C (I along section In this case, case currents one tra circulatg subsection are represented A1t1 ) two tras circulatg C (IA1t1) for two tras s circulatg along subsections A B (I subsections section A case B A1t2 ). (IA1t2). one tra circulatg subsection C (IA1t1) two tras circulatg The results for s catenary are presented 12, where subsections The results A for B (IA1t2). currents case no s tras section catenary are also presented. are On presented or h, 12, cases where currents The results for case no s tras section catenary are also presented. are On presented or h, 12, cases where s feeder are presented 13. currents s case feeder no tras section are presented are also presented. 13. On or h, cases Accordg to results, fluence tra circulation is negligible, as currents supplied by Accordg s results, feeder fluence are presented tra circulation is negligible, 13. autotransformer are similar all cases. as currents supplied by Accordg autotransformer to results, are similar fluence all cases. tra circulation is negligible, as currents supplied by autotransformer are similar all cases.

10 Energies 218, 11, x FOR PEER REVIEW 1 2 Energies 218, 218, 11, 11, 161 x FOR PEER REVIEW Current [A] [A] A2 A3 A1t1 t1 A2t1 t1 A3t1 t1 A1t2 t2 A2t2 t2 t2 A3t Distance 15 [km] Simulated currents AT1, AT2, SATS for different Simulated currents AT1, AT2, AT1, AT2, SATS forsats different for different locations. locations. catenary rail. Cases: (a) no tras (IAi), (b) one tra at midpot locations. catenary catenary rail. Cases: (a) rail. nocases: tras (a) (I Ai no ), (b) tras one tra (IAi), (b) at one midpot tra at subsection midpot C subsection C (IAit1), (c) two tras at midpot subsections A B (IAit2). (Isubsection Ait1 ), (c) two (IAit1), tras (c) at two midpot tras at subsections midpot Asubsections B (I Ait2 ). (IAit2). Current [A] [A] A2 A3 A1t1 t1 A2t1 t1 A3t1 t1 A1t2 t2 A2t2 t2 t2 A3t Distance 15 [km] Simulated currents AT1, AT2, AT1, AT2, SATS forsats different for different locations. 13. Simulated currents AT1, AT2, SATS for different locations. feeder rail. feeder Cases: (a) rail. nocases: tras (a) (I Ai no ), (b) tras one (IAi), tra(b) at one midpot tra at subsection midpot C locations. feeder rail. Cases: (a) no tras (IAi), (b) one tra at midpot (Isubsection Ait1 ), (c) C (IAit1), two tras (c) at two midpot tras at subsections midpot Bsubsections C (I Ait2 B ). C (IAit2). subsection (IAit1), (c) two tras at midpot subsections (IAit2). Durg Durg acceleration acceleration tra, tra, power power consumption consumption is is is maximal, maximal, but but case case constant-speed constant-speed operation, operation, power power power is is considerably considerably reduced. Also considered simulations is considerably reduced. reduced. Also Also considered considered simulations simulations are tras are tras at one third ir maximum power (4.88 MW), representg constant-speed are tras at oneat third one third ir maximum ir maximum power (4.88 power MW), (4.88 representg MW), representg constant-speed constant-speed operation. Ground operation. Ground s rail along section are presented 14, operation. s Ground s catenary catenary rail along rail section along are presented section are presented 14, representg 14, representg case one tra circulatg midpot subsection C (IA1t1) two tras representg case one tra case circulatg one tra circulatg midpot subsection midpot C (t1 subsection ) two (IA1t1) tras circulatg two tras subsections circulatg subsections A B (IA1t2), second one at constant-speed operation. The results are circulatg A subsections B (t2 ), second (IA1t2), one at second constant-speed one at constant-speed operation. The operation. resultsthe are similar results are to those similar to those presented 12. similar presented to those presented

11 Energies 218, 11, 11, 161 FOR PEER REVIEW Energies 218, 11, x FOR PEER REVIEW Tra 14.6 MW Tra 1 = 14.6 MW Tra 4.88 MW Tra 2 = 4.88 MW A1 A2 5 5 A3 t1 A1t1 Current [A] [A] t1 A2t1 t1 A3t1 t2 A1t2 t2 A2t2 2 2 t2 A3t Distance 15 [km] Simulated currents AT1, AT2, AT1, AT2, SATS forsats different for different locations. 14. Simulated currents AT1, AT2, SATS for different locations. catenary catenary rail. Cases: (a) rail. nocases: tras (a) (I Ai no ), (b) tras Tra(IAi), 1 at(b) Tra midpot at subsection midpot C locations. catenary rail. Cases: (a) no tras (IAi), (b) Tra 1 at midpot (Isubsection Ait1 ), (c) Tra (IAit1), 1 midpot (c) Tra subsection midpot A subsection Tra 2 midpot Tra subsection midpot B (I Ait2 subsection ). Tra 1 subsection C (IAit1), (c) Tra 1 midpot subsection A Tra 2 midpot subsection B power (IAit2). Tra 14.6 MW power Tra 14.6 MW 2 power 4.88 Tra MW. (IAit2). Tra 1 power 14.6 MW Tra 2 power power MW. MW Simulations Simulations Influence Influence Resistance Resistance In In order order to to to study study study fluence fluence on on on angles angles angles current current current voltage voltage voltage current modules current current modules modules when when when occurs withoccurs an arcwith resistance, arc arc numerous resistance, resistance, simulations numerous numerous simulations simulations have been performed. have have been been performed. performed. The The simulations are are based based on on system system presented presented In In se se simulations, a a resistance resistance (R) (R) Ω has has been been used, used, as as as described described previous previous section. section. Catenary rail s s feeder rail feeder rail s s were were simulated simulated along along section. section. V C1 C1 A1 V C2 C2 A2 R V C3 C3 A3 TS TS Traction Traction Substation Substation ATS ATS 1 ATS ATS 2 SATS SATS Subsection Subsection A Subsection Subsection B Subsection Subsection C kv kv simulation simulation model model for for s s with with an an arc arc resistance resistance R. R kv simulation model for s with an arc resistance R Influence Influence Resistance Resistance on on Current-Voltage Current-Voltage Phase Phase Autotransformer Autotransformer Case Case a Ground Influence Resistance on Current-Voltage Phase Autotransformer Case a Ground Ground shows shows phase phase angle angle currents currents voltages voltages at at different different 16 shows case phase catenary angle with currents an arc resistance voltages.29 at Ω. different case a catenary with an arc resistance.29 Ω. Additionally, case 17 a shows catenary phase angle with an arc resistance current.29 Ω. Additionally, 17 shows phase angle current voltage voltage Additionally, case 17 case shows a feeder phase feeder angle with with an an arc arc resistance current resistance Ω. voltage Ω. It It can can be be clearly clearly seen case seen that a feeder that both both cases, cases, deviations with an arc deviations resistance angles angles are.29 are small. Ω. small. These These small small deviations deviations phase phase angle angle do do not not produce produce correct correct operation operation directional directional overcurrent overcurrent relays relays because because se se relays relays have have a phase phase angle angle trippg trippg range range area area ±3. ±3.

12 Energies 218, 11, Energies 218, It can 11, be x FOR clearly PEER seen REVIEW that both cases, deviations angles are small. These 12 small 2 deviations Energies 218, 11, x FOR phase PEER angle REVIEW do not produce correct operation directional overcurrent relays because se relays have a phase angle trippg range area ± V C1 -V C ATS ATS ATS ATS SATS SATS 16. Phase angles IA VC at different ATSs as a function distance from 16. Phase angles I 16. Phase angles A V IA C at different ATSs as a function distance from to substation. catenary VC at different ; ATSs resistance as a function.29 Ω. distance from to substation. catenary ; resistance.29 Ω. to substation. catenary ; resistance.29 Ω. -V C2 -V C3 -V C2 -V C V C ATS ATS ATS ATS SATS SATS 17. Phase angles I 17. Phase angles IA A V VC at C at different ATSs as a function distance from different ATSs as a function distance from to substation. considered feeder ; resistance.29 Ω. to 17. substation. Phase angles considered IA VC at feeder different ATSs ; as a function resistance distance.29 Ω. from to substation. considered feeder ; resistance.29 Ω Influence Influence Resistance Resistance on on Autotransformer Autotransformer Currents Currents Case Case a Ground a Ground Influence Resistance on Autotransformer Currents Case a Ground The The current current modules modules when when a a happens happens catenary catenary are are shown shown The current modules Two Two cases cases are are presented: presented: (1) (1) without without when a resistance resistance happens (2) with (2) an with arc catenary resistance an arc are resistance shown.29 Ω..29 Ω. 18. Two cases are presented: (1) without resistance (2) with an arc resistance Additionally, Additionally,.29 a Ω. comparison a comparison current current modules modules with with feeder feeder s s with Additionally, with or or without without a comparison resistance resistance are are shown current shown modules with feeder s As As shown with shown or without s s resistance 19, 19, fluence are fluence shown 19. resistance resistance on on current current values values As shown is significant. is s significant. 18 The The 19, different different fluence two two cases resistance cases is less less on than than 1.5% current 1.5% any values any case. case. is significant. The different two cases is less than 1.5% any case. -V C2 -V C3 -V C1 -V C2 -V C3

13 Energies 218, 11, x FOR PEER REVIEW 13 2 Energies 218, 11, 11, 161 x FOR PEER REVIEW Current [A] Current [A] CAT1 CAT1 I CAT1 CAT1 CAT2 CAT1 CAT2 CAT1 CAT2 A1CAT2 CAT2 CAT ; CAT1: R= Ohm; CAT2: R=.29 Ohm Simulated currents Distance [km] ; CAT1: R= Ohm; CAT2: AT1, R= AT2,.29 Ohm SATS for different locations. catenary rail. Cases: (1) CAT1 no resistance, (2) CAT2 18. Simulated currents AT1, AT2, SATS for different locations. resistance 18. Simulated.29 Ω. currents AT1, AT2, SATS for different catenary rail. Cases: (1) CAT1 no resistance, (2) CAT2 resistance.29 Ω. locations. catenary rail. Cases: (1) CAT1 no resistance, (2) CAT2 resistance.29 Ω. 7 Current [A] Current [A] CAT1 CAT1 CAT1 A1CAT1 CAT2 A2CAT1 CAT2 A3CAT1 CAT2 A1CAT2 CAT2 CAT ; CAT1: R= Ohm; CAT2: R=.29 Ohm Simulated Simulated currents currents Distance [km] ; AT1, AT2, CAT1: R= Ohm; CAT2: AT1, R= AT2, SATS.29 for OhmSATS different for different locations. locations. feeder rail. feeder Cases: (1) CAT1 no rail. Cases: (1) resistance, CAT1 no (2) CAT2 resistance, resistance (2) CAT2.29 Ω. resistance 19. Simulated.29 Ω. currents AT1, AT2, SATS for different 5. Experimental locations. Tests feeder rail. Cases: (1) CAT1 no resistance, (2) CAT2 5. Experimental resistance.29 Tests For computerω. simulations, numerous experimental tests have been conducted laboratory to verify For fluence computer tra simulations, circulationumerous arc resistance. experimental A simplified tests have diagram been conducted experimental setup 5. laboratory Experimental is presented to verify Tests fluence 2. tra circulation arc resistance. A simplified diagram experimental The For experimental computer setup is setup presented simulations, is displayed numerous experimental It simulatestests circuit have been conducted 2. In setup, laboratory substation to verify was executed fluence by a power tra source circulation (1) arc two resistance. wdga traction simplified transformers diagram were implemented experimental by setup twois transformers, presented (2) (3), 2. providg 25 V AC each. This implies a 1-fold voltage reduction compared to real 2 25 kv power system. The section comprised three subsections divided by ATS 1, ATS 2, SATS (4). The impedances feeder catenary were executed by ductive impedances (5). The ratgs se impedances () were.5 + j5 Ω. Furrmore, rail impedance was considered significant, refore no impedance was connected. To perform s along each subsection, variable impedances 1 2 (6) were employed. These variable ductances had.5 + j5 Ω each, with 1 taps available. So, impedance

14 2. Simplified diagram laboratory setup for testg a 2 25 kv power system. The experimental setup is displayed 21. It simulates circuit 2. In setup, substation was executed by a power source (1) two wdg traction transformers Energies 218, 11, were implemented by two transformers, (2) (3), providg 25 VAC each. This implies a 1-fold voltage reduction compared to real 2 25 kv power system. The section comprised three per km was.1 + j1 Ω/km. to represent ATS tras 2,arc resistances, resistors subsections divided by Fally, 1, ATS SATS (4).some The adjustable impedances were used (7). The values impedance were similar to values 2 25 kv power systems. feeder catenary Energies 218, 11, x FORwere PEER executed REVIEW by ductive impedances (5). The ratgs se impedances 14 2 () were.5 + j5 Ω. Furrmore, rail impedance was considered significant, refore no 1 To 2perform variable impedances 1 impedance was connected. s along each subsection, 2 (6) were employed. These variable ductances had.5 + j5 Ω each, with 1 taps available. So, impedance per km was.1 + j1 Ω/km. Fally, to represent tras arc resistances, IA1 IA3 some R adjustable resistors were used (7). The values impedance were similar to values 2 25 kv power systems. As values voltages were 1 times smaller values impedances were similar to values 2 25 kv power system, currents measured experimental setup are 1 times smaller. In or words, a volt represents a kilovolt an amp represents a ATS 1 ATS 2 SATS kiloampere. Traction TheSubstation currents IA1, IA2, IA3 were measuredsubsection experimental setup. The Subsection A B Subsection C currents were flowg through case s rail catenary rail 2. Simplified feeder. The s were performed section a 3-km diagram laboratory setup for along a testg asimulatg 2 25 kv power 2. Simplified diagram laboratory setup for testg a 2 25 kv power system. length.system. The s were performed every.5 km. The experimental setup is displayed 21. It simulates circuit 2. In setup, substation was executed by a power source (1) two wdg traction transformers were implemented by two transformers, (2) (3), providg 25 VAC each. This implies a 1-fold voltage reduction compared to real 2 25 kv power system. The section comprised three subsections divided by ATS 1, ATS 2, SATS (4). The impedances feeder catenary were executed by ductive impedances (5). The ratgs se impedances () were.5 + j5 Ω. Furrmore, rail impedance was considered significant, refore no impedance was connected. To perform s along each subsection, variable impedances 1 2 (6) were employed. These variable ductances had.5 + j5 Ω each, with 1 taps available. So, impedance per km was.1 + j1 Ω/km. Fally, to represent tras arc resistances, some adjustable resistors were used (7). The values impedance were similar to values 2 25 kv power systems. As values voltages were 1 times smaller values impedances were similar to values 2 25 kv power system, currents measured experimental setup are 1 times smaller. In or words, a volt represents a kilovolt an amp represents a kiloampere. The currents IA1, IA2, IA3 were measured experimental setup. The currents were 21. Laboratory setup for testg a 2 25 kv power system. 21. Laboratory setup for testg a 2s 25 kv power system. flowg through case rail catenary rail feeder. The s were performed along a section simulatg a 3-km length. The were performed km. values impedances were As values s voltages were 1every times.5 smaller similar to values 2 25 kv power system, currents measured experimental setup are 1 times smaller. In or words, a volt represents a kilovolt an amp represents a kiloampere. The currents IA1, IA2, IA3 were measured experimental setup. The currents were flowg through case s rail catenary rail feeder. The s were performed along a section simulatg a 3-km length. The s were performed every.5 km Experimental Tests on Influence Tra Power Consumption The laboratory tests to analyse effect tra circulation on current values refore on location method were performed accordg to circuit shown 22. The high-speed tra consumption was represented by a 5 Ω resistance. The current through this resistance was equivalent to current a high-speed tra consumg 12.5 MW. This resistance 21. Laboratory setup for testg a 2 25 kv power system.

15 circuit shown The Experimental high-speed Tests tra on consumption Influence Tra was Power represented Consumption by a 5 Ω resistance. The current through this resistance was equivalent to current a high-speed tra consumg 12.5 MW. This The laboratory tests to analyse effect tra circulation on current values resistance R was connected catenary rail different positions; for example, refore on location method were performed accordg to 21, it was placed midpot section B. Energies circuit 218, 11, shown The high-speed 1tra 2consumption was represented by a 5 Ω resistance. The current through this resistance was equivalent to current a high-speed tra consumg 12.5 MW. This R was connected catenary rail different positions; for example, 21, it was resistance R was connected catenary rail different positions; for example, placed midpot section B. R 21, it was placed midpot section B. 1 2 R Traction Substation ATS 1 ATS 2 Subsection A Subsection B Subsection C SATS 22. Laboratory setup for ATS 1 testg a 2 25 ATS kv power 2 system with a SATS high-speed Traction tra Substation midpot section B simulated by resistance. Subsection A Subsection B Subsection C The results experimental tests are presented s for catenary feeder s, respectively. Laboratory setup setup for for testg testg a 2 a kv kv power system with with a high-speed a In tra tra 23, midpot current section section modules B simulated B by by resistance. IA1, IA2, IA3 are represented for different catenary s along 3-km section with a tra midpot subsection B The The results results experimental experimental tests tests are are presented presented s s for for catenary catenary feeder feeder (1t2). In addition, tests without high-speed tras are cluded (t) to be able to make a comparison. s, s, respectively. respectively. In 23, current modules IA1, IA2, IA3 are represented for different 14 catenary s along 3-km section with a tra midpot subsection B (1t2). In addition, tests without high-speed tras are cluded (t) to be able to make a comparison. Current [ma] Current [ma] Autotransformer current distribution tests with a catenary rail Cases: (a) no tras (I Ait ), (b) one tra midpot Distance [km] subsection B (I Ai1t2 ). In , Autotransformer current modules current distribution tests with I a catenary A1,, are represented for different rail. catenary Cases: (a) no tras s (IAit), along (b) one tra 3-km section midpot with a subsection tra B (IAi1t2). midpot subsection B (1t2). In addition, tests without high-speed tras are cluded (t) to be able to make a comparison. In 24, current modules,, are represented for different feeder s along 3-km section. In this figure, cases a tra midpot subsection C (I Ai1t3 ) two tras midpot subsections A C (I Ai2t1y3 ) are presented. In addition, tests without high-speed tras are cluded (t) order to compare results. It is clearly observed from results presented s that fluence tras on autotransformer currents is irrelevant, even case two tras runng same I 1t2 t 1t2 t 1t2 A3t 23. Autotransformer current distribution tests with a catenary rail. Cases: (a) no tras (IAit), (b) one tra midpot subsection B (IAi1t2). t t t 1t2 1t2 1t2

16 1 1t3 1t3 6 I Energies 218, 11, 161 A32t1y Energies section 218, 11, simultaneously. x FOR PEER 2 REVIEW Also, experimental results are similar to simulation results testg 16 2 reliability this location method t 24. Autotransformer current distribution tests with a I 12 A2t feeder rail. Cases: (a) no tras (IAit), (b) one tra midpot subsection C (IAi1t3), t (c) two tras midpot subsection A C (IAi2t1y3). I 1 A11t3 1t3 8 1t3 2t1y3 6 2t1y3 2t1y3 In 24, current modules IA1, IA2, IA3 are represented for different feeder s along 3-km section. In this figure, cases a tra midpot subsection C (IAi1t3) two tras midpot subsections A C (IAi2t1y3) are presented. In addition, tests without high-speed tras are cluded 4(t) order to compare results. It is clearly observed from results presented s that fluence Current [ma] Current [ma] 8 4 tras on 2autotransformer currents is irrelevant, even case two tras runng same section simultaneously. Also, experimental results are similar to simulation results testg reliability this location method Laboratory Tests Influence Resistance Autotransformer current current distribution tests tests with with a a feeder feeder rail. rail. Cases: In order (a) no to tras study (I Cases: (a) no tras (IAit), Ait ), fluence (b) one tra midpot resistance, subsection circuit C (I (b) one tra midpot subsection Ai1t3 presented ), (c) two tras 25 was C (IAi1t3), (c) two tras used. midpot A resistance subsection (R) A C.3 (I Ai2t1y3 Ω was ). stalled catenary or feeder midpot dependg subsection on A test. C (IAi2t1y3) Laboratory The results Tests Influence experimental ests Resistance are presented s for catenary feeder In s, 24, respectively. current modules IA1, IA2, IA3 are represented for In order to study fluence resistance, circuit presented 25 was used. different feeder In s 26 s 27, along current 3-km modules section. IA1, IA2, IA3 are A resistance (R).3 Ω was stalled catenary or feeder In represented this figure, for catenary cases a feeder tra midpot s, respectively, subsection along C (IAi1t3) 3-km section. two In tras se dependg on test. midpot tests, different subsections resistances A C (IAi2t1y3).3 are Ω presented. have been In used. addition, tests without high-speed tras are cluded (t) order to compare results. It is clearly observed from results presented s that fluence tras on autotransformer currents is irrelevant, even case two tras runng same section simultaneously. Also, experimental results are similar to simulation results testg reliability this location method Laboratory Tests Influence Resistance In order to study fluence resistance, circuit presented 25 was used. A resistance (R).3 Ω was stalled catenary or feeder dependg on test. The results experimental tests are presented s for catenary feeder s, 25. respectively. 25. Laboratory Laboratory setup setup for for testg testg a 2 25a kv 2 power 25 kv system power with system resistances. with resistances. In s 26 27, current modules IA1, IA2, IA3 are The results experimental tests are presented s for catenary feeder represented for catenary feeder s, respectively, along 3-km section. In se s, respectively. tests, different In s 26resistances 27, current modules.3 Ω have been used.,, are represented for catenary feeder s, respectively, along 3-km section. In se tests, different resistances.3 Ω have been used. It can be observed from results presented s that experimental results are similar to results simulations. We can conclude that fluence resistance on autotransformer currents is significant. 1t3 2t1y3 2t1y3

17 Energies 218, 11, x FOR PEER REVIEW 17 2 Energies Energies 218, 218, 11, , x FOR PEER REVIEW Current [ma] Current [ma] R3 I R3 R3 A2 R3 4 R3 8 R Distance[km] Autotransformer current distribution tests with a catenary rail with resistances : (a) Ω (b).3 Ω Distance[km] It can be observed from results presented s that experimental results are similar to results simulations. We can conclude that fluence resistance on Autotransformer current current distribution tests tests with with a a catenary rail autotransformer withrail with resistances resistances currents : (a) : is Ω(a) significant. Ω (b).3(b) Ω..3 Ω. It can 14 be observed from results presented s that experimental results are similar to results simulations. We can conclude that fluence resistance on autotransformer currents is significant. 12 Current [ma] R3 I R3 R3 A2 R3 Current [ma] I 4 A2R3 8 R Distance[km] Autotransformer 27. current distribution tests with a feeder rail rail with with resistances resistances (a) (a) Ω Ω (b) (b).3.3 Ω. Ω Distance[km] 5.3. Validation Experimental Setup by Simulations 5.3. Validation Experimental Setup by Simulations In order 27. Autotransformer verify experimental current distribution setup, we have tests with developed a simulation feeder model with rail In order to verify experimental setup, we have developed a simulation model with impedances with used resistances (Table (a) 2). The Ω results (b).3 Ω. simulations ( 28) are very close to impedances used (Table 2). The results simulations ( 28) are very close to experimental experimental results (s 23, 24 26). results 5.3. Validation (s 23, 24 Experimental 26). Setup by Simulations In order to verify Table experimental 2. Self-impedance setup, values we have railway developed conductors. Table 2. Self-impedance values railway conductors. a simulation model with impedances used (Table 2). The Conductor results Impedance simulations (Ω/km) ( 28) are very close to experimental results (s 23, 24 Catenary 26). C Conductor Impedance.1 + j1. (Ω/km) Feeder F.1 + j1. Catenary Table 2. Self-impedance Rail R values C.1 + j1. railway conductors. Feeder F.1 + j1. Rail Conductor R Impedance (Ω/km) Catenary C.1 + j1. Feeder F.1 + j1. The short-circuit current distributions results obtaed experimental setup Rail R simulations are similar to results presented [19]. This reference is one most prestigious references short-circuit current calculation 2 25 kv power systems.

18 Energies 218, 11, x FOR PEER REVIEW 18 2 The short-circuit current distributions results obtaed experimental setup simulations are similar to results presented [19]. This reference is one most prestigious Energies references 218, 11, short-circuit 161 current calculation 2 25 kv power systems Current [A] Currents obtaed simulations AT1, AT2, SATS experimental model. 6. Conclusions In this paper, fluence tra circulation arc resistance on a novel method location for 2 25 kv traction power systems has been studied. The location system is based on measurement voltages currents compared to previous oretically calculated values. Previously, analysis phase angle voltages currents defes subsection conductor, catenary or feeder, where takes place. As tra circulation resistances modify oretically calculated current current values values, se se factors factors could could produce produce errors errors location location s. s. These fluences have been studiedby by computer simulations experimental tests tests laboratory. After numerous simulations, maximum error current does not reach 5%. On or h, experimental tests, maximum error error current current does does not not reach reach 6%. 6%. The ma conclusion this paper is that location method is not significantly fluenced by tra The circulation ma conclusion arc this paper resistances, that so location use this method method is not facilitates significantly location fluenced by tra circulation. arc resistances, so use this method facilitates location. Author Contributions: C.A.P. performed laboratory tests wrote manuscript. J.S. developed simulation models reviewed manuscript. M.L.-T. revised improved simulation model. R.G. Author Contributions: C.A.P. performed laboratory tests wrote manuscript. J.S. developed analyzed results checked manuscript. simulation models reviewed manuscript. M.L.-T. revised improved simulation model. R.G. Fundg: analyzed Thisresults research received checked no external manuscript. fundg. Conflicts Interest: The authors declare no conflict terest. Fundg: This research received no external fundg. Abbreviations Conflicts Interest: The authors declare no conflict terest. The followg abbreviations are used this manuscript: Abbreviations AC: Alternatg current AT: The followg Autotransformer abbreviations are used this manuscript: ATS: AC: Autotransformer Alternatg current station I: AT: Autotransformer current ATS: : Catenary Autotransformer current station autotransformer 1 : Catenary current autotransformer 2 : Catenary current autotransformer 3 i: Autotransformer number: 1, 2, 3,..., N

19 Energies 218, 11, I Ai : Current put from catenary autotransformer i L: Arc length R Arc resistance SATS: Autotransformer station at end section V1: Voltage source 1 V2: Voltage source 2 V Ci : Catenary voltage autotransformer i : Experimental setup ductive impedance 1: Experimental setup adjustable ductive impedance 1 2: Experimental setup adjustable ductive impedance 2 C : Catenary self-impedance value per unit length F : Feeder self-impedance value per unit length R : Rail self-impedance value per unit length CF : Mutual impedance catenary feeder value per unit length CR : Mutual impedance catenary rail value per unit length FR : Mutual impedance feeder rail value per unit length References 1. Hill, R.J. Electric Railway Traction. Part 3. Traction Power Supplies. Power Eng. J. 1994, 8, [CrossRef] 2. Mariscotti, A.; Pozzobon, P.; Vanti, M. Distribution Traction Return Current AT Electric Railway Systems. IEEE Trans. Power Deliv. 25, 2, [CrossRef] 3. Areva T&D. Network Protection & Automation Guide; Areva T&D Energy Automation & Information: Levallois-Peret, France, 22; Volume 2, pp hou, Y.; Xu, G.; Chen, Y. Location Power Electrical Traction Le System. Energies 212, 5, [CrossRef] 5. L, G.S.; Li, Q.. Impedance Calculations for AT Power Traction Networks with Parallel Connections. In Proceedgs 21 Asia-Pacific Power Energy Engeerg Conference, Chengdu, Cha, March 21; pp Agarwal, K.K. Automatic Location Isolation System for Electric Traction Overhead Les. In Proceedgs 22 ASME/IEEE Jot Railroad Conference, Washgton, DC, USA, April 22; pp Hewgs, D.B.; Chen, J.; Storey, A.P. Application a New Distance Protection Scheme to a Sgle-Pole Autotransformer Electrification System on UK West Coast Ma Le Railway. In Proceedgs IET 9th International Conference on Developments Power System Protection, Glasgow, Scotl, UK, 17 2 March 28; pp Fujie, H.; Miura, A. Location System Autotransformer Feedg Circuit AC Electric Railways. Electr. Eng. Jpn. 1976, 5, [CrossRef] 9. Wang, C.; Y, X. Comprehensive Revisions on -Location Algorithm Suitable for Dedicated Passenger Le High-Speed Electrified Railway. IEEE Trans. Power Deliv. 212, 27, [CrossRef] 1. Lee, H.; Oh, S.; Kim, G.; An, C. A Study on Equivalent Conductor Representation AC Electric Railway System. In Proceedgs 29 International Conference on Information Multimedia Technology, Jeju Isl, South Korea, December 29; pp Wang, X.; Qian, Q.; Chen, W. Analyzg -Induced Transients with Wavelets. In Proceedgs IEEE Power Engeerg Society Summer Meetg, Chicago, IL, USA, July 22; pp hang, D.; Wu, M.; Xia, M. Study on Travelg Wave Location Device for Electric Railway Catenary System Based on DSP. In Proceedgs International Conference on Sustaable Power Generation Supply, Nanjg, Cha, 6 7 April 29; pp Xu, G.; hou, Y.; Chen, Y. Model-Based Location with Frequency Doma for Power Traction System. Energies 213, 6, [CrossRef] 14. Battistelli, L.; Pagano, M.; Proto, D. Short Circuit Modellg Simulation 2 25 kv High Speed Railways. In Proceedgs Second Asia International Conference on Modellg & Simulation (AMS), Kuala Lumpur, Malaysia, May 28; pp

20 Energies 218, 11, Serrano, J.; Platero, C.A.; López-Toledo, M.; Granizo, R. A Novel Ground Identification Method for 2 25 kv Railway Power Supply Systems. Energies 215, 8, [CrossRef] 16. Serrano, J.; Platero, C.A.; López-Toledo, M.; Granizo, R. A New Method Ground Location 2 25 kv Railway Power Supply Systems. Energies 217, 1, 34. [CrossRef] 17. Andrade, V.; Sorrento, E. Typical Expected Values Resistance Power Systems. In Proceedgs IEEE/PES Transmission Distribution Conference Exposition: Lat America (T&D-LA), Sao Paulo, Brazil, 8 1 November 21; pp Wedepohl, L.M.; Jackson, L. Modified nodal analysis: An essential addition to electrical circuit ory analysis. Eng. Sci. Educ. J. 22, 11, [CrossRef] 19. Chen, T.-H.; Hsu, Y.-F. Systematized short-circuit analysis a 2 25 kv electric traction network. Electr. Power Syst. Res. 1998, 47, [CrossRef] 218 by authors. Licensee MDPI, Basel, Switzerl. This article is an open access article distributed under terms conditions Creative Commons Attribution (CC BY) license (