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Electric P ower S upply Q uality Concepts for the All E lectri c Ship

Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras. Electric P ower S upply Q uality Concepts for the All E lectri c Ship I.K. Hatzilau, Prof. Dr.-Ing. , Hellenic Naval Academy

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Electric P ower S upply Q uality Concepts for the All E lectri c Ship

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  1. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Electric Power Supply Quality Concepts for the All Electric Ship I.K. Hatzilau, Prof. Dr.-Ing., Hellenic Naval Academy J. Prousalidis, Ass. Prof., National Technical University of Athens E. Styvaktakis, PhD, Hellenic Transmission System Operator F. Kanellos, PhD, postdoc S. Perros,MSc Electrical Eng., Cdr Hellenic Navy E. Sofras, PhD Cand., National Technical University of Athens 1

  2. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras What is the Scope of the Paper ? The All Electric Ship concept comprises electrification of all systems onboard via the extensive usage of power electronic devices. In addition, there are large power loads(electric propulsion, pulsed loads) and the trend is forapplication of High Voltage. Therefore, Power Supply Quality problems are expected to be extremely important and special interest must be focused on them. presented by I.K. Hatzilau 2 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 2

  3. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Paper Scope • This paper aims : • - To inform on Power Supply Quality problem • and to make a short description and categorisation • of the PSQ phenomena . • (causes, consequences, characteristic parameters ..etc). • To investigate, discuss and compare • the different standardsapplied in shipboard applications, • ( with special consideration of NATO STANAG 1008 ) • taking also into account, • the standard status of similar continental power systems. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 3

  4. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Paper Scope Due to similarities of ship power systemsto continental grids, it can be argued, that the standards issued for ordinary electric systems can be applied to ships and AES in particular, too. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 4

  5. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Paper Scope • The standards mainly studied for the purposes of this paper are : • IEEE 1159 and IEEE 519 referring to continental grids. • IEEE 45 and IEC-60092/101mainly dealing with general ship network installations. • Classification Society Rules mainly referring to normal operation of electric networks of commercial ships. • -STANAG-1008 referring to the electrical power plants in NATO naval vessels(under the responsibility of the NATO AC/141(NG/6)SubGroup/4). WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 5

  6. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras CONTENTS … the paper arrangement is the following :1. Introduction and Background2. Harmonics3. Spikes, Transients, Dips, Swells 4. Modulation / Pulsed Loads 5. Voltage Unbalance 6. Leakage Capacitive Currents 7. Other PSQ issues 8. Conclusion 9. Acknowledgements10. References WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 6

  7. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 1. INTRODUCTION and BACKGROUND Power Supply Quality (P.S.Q.) is a term referringto a wide variety of disturbances in electric networks, either ship or continental ones . * Electric networks suffer from … “Harmonics” “Short time duration non-periodical disturbances ” like Spikes / Transients / Dips / Swells“Voltage and Frequency Modulation”(due to pulsed loads),“Voltage Unbalance” “Leakage Capacitive Currents” “Voltage interruptions” … etc …. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 7

  8. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 1. INTRODUCTION and BACKGROUND From a certain point of view, PSQ phenomena can be classified into two main categories, i.e. : · *Steady-state phenomena, which have inherent periodicity and they are repeated on almost constant basis without significant changes, such as harmonics and unbalance,while there is also a stochastic parameter included in certain cases like notching, flickering etc. · * Transient-state phenomena, which are of limited duration and they are characterized by significant changes, such asspikes and transients like dips, swells. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 8

  9. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 1. INTRODUCTION and BACKGROUND It is worth noting, that although all these phenomena are treated as Power Quality aspects, they actually refer to the fundamental electric supply quantities, like Voltage, Frequency and possibly Current. Voltage and Frequency consist the main system characteristic quantities, that have to be kept intact and well within the limits set by the standards. The Current, on the contrary, is a quantity affecting power quality in an indirect manner and via voltage drop on system and equipment impedances. Should the current not comply with the limitations, set by certain standards, it is possible that voltage and/or frequency will be influenced, too. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 9

  10. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS Harmonic distortion of periodic voltage or current waveforms is mainly due to power electronic devices, used onboard to couple and control different operating voltage and frequency levels, motor drives etc. Based on the mathematical Fourier analysis, the well-known standard definitions on harmonic power qualityare the following: WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 10

  11. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS Definitions Harmonic Power Quality Definitions Voltage harmonics Current harmonics Total VoltageHarmonic Distortion (THDv) Total CurrentHarmonic Distortion (THDI) J.M. Prousalidis, I.K. Hatzilau, S.Perros 11 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 11

  12. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS Definitions The Total Demand Distortion (TDD) According to THD definition, both the fundamental component and the high order harmonics should be measured simultaneously. However, ifthe fundamental equalsan average quantity over a specific time interval, then the index is called Total Demand Distortion (TDD) J.M. Prousalidis, I.K. Hatzilau, S.Perros 12 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 12

  13. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS impacts The impacts of harmonic voltage and/or current distortion include a wide range of phenomena, like : *Extra heating lossesin electric machinery and cable wiring ·  *Decrements in accuracy of measuring equipment. · *Excitation of resonance phenomena resulting in significantovervoltages and/or overcurrents. · *False tripping of protective switchgear (e.g. fuse blowing, orincorrect thermal relays actuation). ·  *Failure of equipment sensitive to harmonics. · *EMI problems with sensitive electronic equipment (navigation, communication, control and automation) ·  *Erection of mechanical oscillations, vibrations, mechanical stresses and noisedue to harmonic torque ripples produced. J.M. Prousalidis, I.K. Hatzilau, S.Perros 13 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 13

  14. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Referring to average maximum fundamental load over a specified period Current distortion is recognised as a problem, but no tangible solution is outlined 2. HARMONICS Comparison among standards * Comparison among standards on HARMONIC P.Q. In this table the VOLTAGE and CURRENT distortion limits by the various standards studied are summarized WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 14

  15. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS VOLTAGE distortion limits VOLTAGE distortion limits • # TOTAL VOLTAGE Harmonic Distortion(THDV) • According to all standards • Total Voltage Harmonic Distortion(THDV) must not exceed • 5% or 8%of the fundamental. • * 8% limitation is set • by LRS • and by GL for systemswherestatic power converters predominate. • Furthermore, according to LRS , • should the system is to be of class “ES1”, • then standards of STANAG 1008 should be applied instead. • Furthermore, there seems to be no clear way of estimating voltage distortion, by investigating the current distortion caused by each separate load. J.M. Prousalidis, I.K. Hatzilau, S.Perros 15 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 15

  16. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICSVOLTAGE distortion limits # TheINDIVIDUAL VOLTAGE Harmonics(Vn) limits versus harmonic order, of all standards studied, are summarized in this figure. J.M. Prousalidis, I.K. Hatzilau, S.Perros 16 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 16

  17. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICSVOLTAGE distortion limits Measurements performed on several types of ships have shownno violation of any VOLTAGE harmonic constraints, set by any of the standards studied J.M. Prousalidis, I.K. Hatzilau, S.Perros 17 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 17

  18. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS CURRENT distortion limits CURRENT distortion limits # TOTAL CURRENT Harmonic Distortion(THDI / TDDI) * Only IEEE-519 sets limits for TDDI , but no limit for THDI The Total CurrentDemand Distortion(TDDI) on Point of Common Coupling(PCC)must not exceed 5 % of the average maximum fundamental load CurrentI1,avfL as this is measured in a specific time interval e.g. 12 months . * byGL, LRS, STANAG 1008andIEC 60092: no numerical limitis set for either THDIor TDDI J.M. Prousalidis, I.K. Hatzilau, S.Perros 18 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 18

  19. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICSCURRENT distortion limits # INDIVIDUAL CURRENT Harmonics(In) GL, LRSand IEC 60092 setno numerical limit , but they offer some comments on possible effects of current harmonic distortion. ---------------------------------------------------------------- * IEEE-519setnumerical limits for In * Ed.8 of STANAG 1008had setstrictnumerical limit for In, .. but the new Edition.9sets no numerical limit for In, instead defines courses of actions to face current distortion problem. J.M. Prousalidis, I.K. Hatzilau, S.Perros 19 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 19

  20. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras log(In/I1,fL) logarithmic-scale Small Loads < (1kVA/60Hz or 0.2kVA/400Hz and 2A/115V/400Hz) log(100) Big Loads > (1kVA/60Hz or 0.2kVA/400Hz and 2A/115V/400Hz) log(3) log(n) log(33) log(100) 2. HARMONICSCURRENT distortion limits # In Edition8of STANAG 1008the limits ofIndividual Harmonics(In ) of each separate loaddepend on load rated powerPr. Ed. 8 distinguished between “small” and “big” loads. for small loads, where Pr < 1kVA ………..…… In/I1≤ 100/n % for n≤ 33 : …… In/I1≤ 3% for n > 33 : …… In/I1≤ 100/n% for bigloads, where Pr > 1kVA These limitations refer to full load fundamental currentI1,fL (which in general is not the value at the measuring instant) and are shown beside WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 20

  21. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICSCURRENT distortion limits In this figure, the current individual harmonic limits, of Edition 8 of STANAG 1008 and IEEE-519, are summarized, but , the limits of each standard refer to different base values (denominators). J.M. Prousalidis, I.K. Hatzilau, S.Perros 21 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 21

  22. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS CURRENT distortion limits • What was the problem with the • CURRENT distortion limitsin Edition 8 of STANAG 1008 ? *Measurements performed on several types of ships, in many navies, have shown, thatthese limits were very strict. -While, ingeneral, the current distortion is significant, itdoes not result in any voltage quality problems. These possible voltage distortion, were the main force for setting the current disortion limits. - Of course this rich current harmonic content could lead to other problems, such as overheating, resonances, false tripping and should therefore be seriously taken into consideration. J.M. Prousalidis, I.K. Hatzilau, S.Perros 22 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 22

  23. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS Case Study CASE STUDY: Measurements on HN MEKOfrigates An example of the above, are the following indicatives measurement results onboard Hellenic Navy MEKO frigates concerning voltage and current harmonics J.M. Prousalidis, I.K. Hatzilau, S.Perros 23 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 23

  24. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS CURRENT distortion limits CASE STUDY: Measurements on HN MEKOfrigates Current Spectra at several load input terminals We have significant CURRENT distortion much higher over the limits of STANAG Ed. 8 …. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 24

  25. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS CURRENT distortion limits CASE STUDY: Measurements on HN MEKOfrigates Voltage Spectra at several load input terminals …. but we dont have any violation of the VOLTAGE limits set by any standard WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 25

  26. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras Pdist,1 Pk Pdist,2 V ZTH Pdist,k P1 2. HARMONICS CURRENT distortion limits #Edition 9of STANAG 1008 sets NO numerical limitfor In of each separate load , butdefines courses of actions to face current distortion problem to the whole system, via the following assistant quantities : 1) ΣkPdist,k: thesum of the power of all loadswhich distortthe currentwaveform connected to the supply system 2) Ssc: theshort circuit power of the generation capacity(Ssc=V2/ZTH) 3) Max (Pdist,k) :thepower of the largest single distorting load Pdist,k : distorting loads Pk : non-distorting loads WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 26

  27. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras ΣkPdist, k Ssc 2 % Analysis required No action 1 % No action No action Max( Pdist, k) Ssc 0.1% 0.5% 2. HARMONICS CURRENT distortion limits These courses of action of Edition 9 of STANAG 1008 are in the following figure. In the yellow area NO measures are required, whereas in the green area : A ) analyses (!!!) to whether STANAG-1008 requirements are stillmet, with respect to voltageharmonics and B ) an early co-ordination, between the system designauthority and theequipmentmanufacturer, should beundertaken. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 27

  28. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras ΣkPdist, k Ssc 2 % Analysis required No action 1 % No action No action Max( Pdist, k) Ssc 0.1% 0.5% 2. HARMONICS CURRENT distortion limits The applicability problemsof these courses of actions suggested by Edition 9, refer : 1) to Simulationson the entire system,computer programs and modelling and 2) to whathappens in case of system upgrading??? WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 28

  29. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS interharmonics Other harmonics issues : “Interharmonics”, “Notching”,”Noise”. ---------------------------------------------------- # Interharmonics It is underlined that no particular limitation is set, by any ship Standard for the interharmonics, the non-integer multiples of the fundamental. J.M. Prousalidis, I.K. Hatzilau, S.Perros 29 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 29

  30. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS “notching” and ”noise” • # “Notching” and ”Noise” • Moreover, two strongly related harmonic distortion PS-issues • with inherent stochastic nature • are the “notching” and ”noise” phenomena, • to which not much attention is paid by any ship Standard. • More specifically : • notching is a periodic voltage disturbance – • - associated with higher frequencies -, • caused by the normal operation of power electronics devices, • due to commutation. • This phenomenon can cause problems, • to power electronic equipment, that use zerocrossings • for frequency or time calculation. J.M. Prousalidis, I.K. Hatzilau, S.Perros 30 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 30

  31. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 2. HARMONICS “notching” and ”noise” • Furthermore,noise comprises signals with broadband spectral content (lower than 200 kHz), • superimposedupon the power system voltage or current • in phase conductors, or found on neutral conductors or signallines … • and it is caused by power electronic devices, control circuits, arcing equipment and switching power supplies. • Noise disturbselectronic devices • such as microcomputer and programmable controllers. • - Solutions to noise problems include filters, isolation transformers etc. • Harmonic and notching problems are expected to significantly increase in the AES perspective as their main causes i.e. power electronic devices are to be extensively applied onboard either for AC/DC conversion or for electric motor variable speed drives. J.M. Prousalidis, I.K. Hatzilau, S.Perros 31 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 31

  32. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS • Switching operations, short-circuits, fuse blowing-up and lightning strikes cause “non-periodical disturbances of short time duration”of voltage and current in electric networks. • * The name of these disturbances varies , • depending on certain characteristics of them. • Thus, terms liketransients,spikes,voltage surges,current surges,sags,dips,swells,etc are often met in relevant documents. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 32

  33. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS SPIKES and TRANSIENTS * A transient and a spike are a sudden, non-power frequency change in voltage or current, or both. They can be unidirectional or oscillatory in polarity. * Switching actions and Lightning are typical causes of spikes and transients. The evolution of the disturbance (waveshape, peak-value, etc) will be influenced by many parameters such as : - Source and surge impedance, - system’s configuration and components, etc… * Spikes and Transients are characterized considering the actual values of the voltage waveform. J.M. Prousalidis, I.K. Hatzilau, S.Perros 33 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 33

  34. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS .. example of a transient : EMTP simulationof aCapacitor switching transient J.M. Prousalidis, I.K. Hatzilau, S.Perros 34 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 34

  35. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS .. Examples of measurements of spikes (shown in different time scales .. ) introduced in AC power system during energization: of a PC-screen (4) and of a PC-Terminal (8). J.M. Prousalidis, I.K. Hatzilau, S.Perros 35 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 35

  36. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS Adverse consequences of spikes & transients- Possible damages to insulation. - Misfiring of Semiconductor switchesby the rate of voltage change, leading to device failures or even errors in data processing devices. - False tripping of adjustable speed drives. - Regarding surge protective devices transients in voltage as well as in current are crucial. Failures have been identified, that are linked to current and not to energy. … etc* It is worth noting that these types of failuresare not often acknowledgedas consequences of power supply voltage or current surges. J.M. Prousalidis, I.K. Hatzilau, S.Perros 36 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 36

  37. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS DIPS and SWELLSVoltage dips are events that present a temporary decrease in the rms voltage. They are caused by an increase in current, somewhere in the system e.g., during motor starting and transformer energizing.A voltage swell is a temporary increase in rms voltage. Swells are usually caused by fault conditions or capacitor inrush.Voltage Dips and Swells are characterized by their rms magnitude and duration.* Voltage dips are responsible for the tripping of computers, electronic equipment and process control equipment.* Like transients, swells can be harmful to electrical insulation. J.M. Prousalidis, I.K. Hatzilau, S.Perros 37 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 37

  38. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS …. Example of Voltage dipduring transformer energizing ( waveform and rms evolution in time ) (up): measurementof Voltage waveform (down):rms voltage and positive peak voltage (thicker) line J.M. Prousalidis, I.K. Hatzilau, S.Perros 38 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 38

  39. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS …. Example of Voltage dip caused from network faults ( waveform and rms evolution in time ) Vdip tdip J.M. Prousalidis, I.K. Hatzilau, S.Perros 39 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 39

  40. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS … Example of Voltage dipduring large power motor starting-up ( waveform and rms evolution in time ) J.M. Prousalidis, I.K. Hatzilau, S.Perros 40 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 40

  41. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS • Comparison of Standards • * In IEEE1159, power electromagnetic phenomena are classified into 7 groups. Groups 1 and 2 are transients and short duration variations (impulsive transient, oscillatory transient, voltage dips and voltage swell). Each group is subdivided further into classes, considering duration, rise time, spectral content, amplitude etc. • The terminology and the “philosophy” of STANAG 1008 • is not always consistent with the standards, • that are widely used in continental systems. • These differences impose difficulties, in directly applying IEEE documents into naval electrical systems, • which would be very favourable, considering COTS exploitation. J.M. Prousalidis, I.K. Hatzilau, S.Perros 41 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 41

  42. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS STANAG 1008classified the transient phenomena of short duration intwocategories:TRANSIENTSandSPIKES. * SPIKE is a transient of short duration. J.M. Prousalidis, I.K. Hatzilau, S.Perros 42 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 42

  43. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS The most problematic issues of STANAG 1008 are the following : *a - Spike peak limits *b - Spike / Transient amplitude(DV)-duration(Dt) diagram. *c - Spike waveshape, Test-impulse J.M. Prousalidis, I.K. Hatzilau, S.Perros 43 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 43

  44. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS *a - Spike peak limits in STANAG 1008The spikes limits[ 2.5 kV for 440 V supply & 1 kV for 115 V supply ]in USA MIL-STD-1399(NAVY)–Section 300Aand in STANAG 1008have been based on measurements performed almosttwenty to thirty years ago, while no actual amendments on this topic have been made. These limits are also adopted in IEEE Std 45-Ed.1998.- These limits have been the outcomes mainly of the measurements of two projects, in year 1972 and in years 1978-1981on U.S. Navy vessels..!! J.M. Prousalidis, I.K. Hatzilau, S.Perros 44 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 44

  45. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS Spike peak limits This diagram is the famous HISTOGRAM of Mr S.F. CANNOVA From this diagram the 2.5 kV Spike-limit is derived, following Measurements on U.S. Navy vessels dated from 1972 ..!! J.M. Prousalidis, I.K. Hatzilau, S.Perros 45 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 45

  46. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS • *b - Spike / Transient • amplitude(DV)-duration(Dt) diagram. • The Limits of voltage Spikes & Transients are represented by a curve • in an amplitude(DV)-duration(Dt) diagram, • separating the permissible and not-permissible areas. • Several standards , like • - ITIC , • - DIN VDE 0160 A1 , • - USA MIL-STD-704E • … etc … • use an intermediate “sloped” section of the curve • in the amplitude-duration diagram, • even if there are some variations between the standards. J.M. Prousalidis, I.K. Hatzilau, S.Perros 46 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 46

  47. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras 3. SPIKES, TRANSIENTS, DIPS, SWELLS • *b - Spike / Transient amplitude(DV)-duration(Dt) diagram. • .. but … Edition 8 of STANAG 1008 • made an abrupt distinction • between “spike” and “transient” • in the amplitude(DV)-duration(Dt) diagram, • in contradiction to the real natural phenomena. • Additionally, in Edition 9 of STANAG 1008, • the criterionfor distinguishing transients from spikes • is not clear and this lead to confusion • Namely, the duration-limitof a spike • overlapswiththe transient-duration-limit… !!! J.M. Prousalidis, I.K. Hatzilau, S.Perros 47 WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 47

  48. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras ITIC STANAG 1008 DV – DT Diagram : STANAG vs ITIC(e.g. for 120 V – 60 Hz) Comparison between ITICcurve and STANAG 1008 (dashed line) Shadowed area : Ed. 9 In ITIC curve two different areas are defined, (for oscillatory and for impulsive transients) having different slopes. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 48

  49. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras ITIC STANAG 1008 DV – DT Diagram : STANAG vs ITIC(e.g. for 440 V) STANAG 1008 Ed.8 distinguishes abruptly. It permits a voltage disturbance of 2000 V, if it has a duration of 990 μsec - because it is a “spike” – but, if the duration is a little longer, e.g. 1010 μsec, the permitted value is much smaller, only about 760 V -because it is “transient” … !!!. WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 49

  50. Electric Power Supply Quality concepts for the All Electric Ship (AES) I.K. Hatzilau, J. Prousalidis, E. Styvaktakis, F. Kanellos, S. Perros, E. Sofras ITIC STANAG 1008 DV – DT Diagram : STANAG vs ITIC(e.g. for 440 V) “Confusion” from the Shadowed area in STANAG Edition 9. So, e.g., a disturbance of 3 msec duration and peak magnitude of 900 V, falls into both categories … !!! It will be acceptable, if we call it “Spike” but not acceptable, if we say, it is a “Transient” … !!! 3 msec WMTC 2006 (World Maritime Technology Conference – INEC stream), LONDON, March 2006 50

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