power quality and surge

Passive Design Part 1 - Introductioin

Power Quality Transient and Surge Protection

Power Quality WorkshopModule PQ Transient & Surge ProtectionVersion 1.00, March 2015

Ir. H.P. Looi ([email protected] presentation2Synopsis HEP and SPDPQ-SPD, V1; February 2015Parts of IEC364 and other IEC standardsdealing with SPD

INTRODUCTION to SPD

Definition and Types of SPD

Number of port, technology type,

Selection of SPD

Risk analysis, Design Check, SPD Selection

Transients Class and SPD

Ir. H.P. Looi ([email protected] presentation

IntroductionPQ-SPD, V1; February 2015Ir. H.P. Looi ([email protected] presentation

4Introduction

Surge Protective Device ?

A device that is intended:to limit transient overvoltages; anddivert surge currents.

It contains at least one non-linear component.PQ-SPD, V1; February 2015Ir. H.P. Looi ([email protected] of SPD contained in IEC61643 series of standards.

PQ-SPD, V1; February 2015Why Surge Protection ?

Increasing sophistication of LV networks.

Increasing use of sensitive equipment.

Lower consumer tolerance for bad PQ.

5IntroductionIr. H.P. Looi ([email protected] need for SPD increases with the growth of data and automation networks. In Malaysia, the implementation of large data and automation networks both in the public and private sector (e.g. campus WAN, hospitals with integrated automation and data networks etc) is driving the need for SPD. The system design engineer cannot ignore the necessity and integration of SPD in wiring design and with this the need for standards are important issues driving the industry.

PQ-SPD, V1; February 20156IntroductionForum on EMC

Forum on Power Quality

Forum on Wiring Installation

Forum on Lightning Protection

Forums dealing with SPD ?

Ir. H.P. Looi ([email protected] above are important forums with interest in SPD at the international and local context.

PQ-SPD, V1; February 2015Transient Class and SPDIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 20158Transient Class & SPD61000-4-4 EFT is in the 100MHz bandwidth range. Note ESD (electrostatic discharge) is in the nano second range. ESD is of particular importance to semiconductor manufacturing facilities.

ST is in the 100kHz bandwidth range.ST is in the micro second range. HEP refers mainly to strong electromagnetic induced pulse such as lightning and atmospheric electromagnetism phenomenon.

2 Types of transients defined in IEC 61000 series (EMC)

61000-4-4 EFT (Electrical Fast Transient) or burst transient

61000-4-5 ST (Slow Transient)

Nanosecond pulseMicrosecond pulseIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 20159Two Types of Transient Class

61000-4-4 EFT (Electrical Fast Transient) or burst transientEFT is in the nano second range (100 MHz bandwidth)Each EFT spike is 100ns . A collection of EFT spikes within 15ms is a burst.EFT principally occurs due to switching surge (current chopping, arc re-ignition in switching etc).Electrostatic discharge (ESD) is also within the nanosecond range

Nanosecond pulseIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 2015102 Types of Transient Class61000-4-5 ST (Slow Transient)ST (Slow Transient) is in the micro second range (100 kHz bandwidth)2 types of ST which isHEP (high energy pulse) switching surges, arc re-ginition in breakers, curren chopping lightning phenomenonLEP (Low energy pulse), switching surges, radiated surge.

Microsecond pulseIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201511Transient Class Switching SurgeWhen the current is chopped or cut to zero within the very short time;The rate of change of current becomes very high.Together with the innate inductance the voltage across the gap will increase to a high value.This will cause the arc to re-strike across the gap.Voltage = Inductance x Rate of Change of CurrentV = -L x di/dt


PQ-SPD, V1; February 201512Transient Class Switching SurgeTRV1 , TRV2 , TRV3 are voltage across the contact gap as current is interrupted.When the voltage reaches breakdown a flashover will occur across the gap.


PQ-SPD, V1; February 201513Transient Class Switching Surge

Voltage = Inductance x Rate of Change of CurrentV = L x di/dtSwitching such a circuit at zero (or near zero) current crossing can cause transient.A highly inductive or capacitive circuit.This presentation focus on High Energy Slow Pulse, Slow TransientIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 2015SPD StandardsIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201515Standards Dealing with SPDPARTS OF MS/IEC 60364 Dealing with SPDPart 5-53 Selection and erection of electrical equipment Isolation, switching and control

Part 4-44 Protection for safety Protection against voltage disturbances and electro-magnetic disturbances


PQ-SPD, V1; February 201516Standards Dealing with SPDIEC Standards dealing with SPDIEC TS 61312-3 Protection against lightning electro-magnetic impulse - Part 3: Requirements of surge protective devices (SPDs)

IEC 61643-1 Surge protective devices connected to low-voltage power distribution systems - Part 1: Performance requirements and testing methods

IEC 61643-12 Low-voltage surge protective devices - Part 12: Surge protective devices connected to low-voltage power distribution systems - Selection and application principles

IEC 61643-21 Low voltage surge protective devices Part 21: Surge protective devices connected to telecommunications and signalling networks Performance requirements and testing methods.

Ir. H.P. Looi ([email protected] TS61312 and IEC61643-12 would have the most relevancy for the system design engineer.

PQ-SPD, V1; February 201517Standards Dealing with SPDIEC Standards dealing with SPDIEC 61643-311 Components for low-voltage surge protective devices - Part 311: Specification for gas discharge tubes (GDT)

IEC 61643-321 Components for low-voltage surge protective devices - Part 321: Specifications for avalanche breakdown diode (ABD)

IEC 61643-331 Components for low-voltage surge protective devices - Part 331: Specification for metal oxide varistors (MOV)

IEC 61643-341 Components for low-voltage surge protective devices - Part 341: Specification for thyristor surge suppressors (TSS)

Ir. H.P. Looi ([email protected] four standards here deals with specific requirement of SPD as a product (product standards).

PQ-SPD, V1; February 2015Types of SPDIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201519Types of SPD by Number of PortsSPD by Number of Ports 1 Port SPD

SPDOne port SPD is connected in shunt with the circuit to be protected.1-port SPD1-port SPDwith separate input/output terminalsIr. H.P. Looi ([email protected] bottom figure is the universal symbol for a 1-port SPD.

PQ-SPD, V1; February 201520Types of SPD 2 PortsSPDTwo port SPD can be connected in different mode (ph-ph, ph-N, ph-E etc). A series impedance is inserted between the terminals.

3 terminals, 2 port4 terminals, 2 portSPD by Number of Ports 2 Port SPD

Ir. H.P. Looi ([email protected] bottom figure is the universal symbol for a 2-port SPD.The connection of the SPD decides how the surge energy is dissipated; either discharged to ground or shunted away from the circuit to be protected via the neutral or main line.

PQ-SPD, V1; February 201521Types of SPD Technology Technology/Design Typevoltage limitingHas a high impedance when no surge is present. Impedance will reduce continuously withincrease surge current and voltagesvoltage switchingHas a high impedance when no surge is present. Impedance will change suddenly in responseto a voltage surge.combinationIncoporates both v-switching and v-limiting types components, may exhibit v-switching or v-limiting or both v-switching & v-limiting behaviour depending on characteristics of applied voltage,

Clamping typeCrowbar type

Ir. H.P. Looi ([email protected] reality there are only two basic technology in SPD design.

PQ-SPD, V1; February 201522SPD Technology Clamping TypeTechnology/Design TypeClamping type(Voltage limiting)

Metal Oxide Varistor (MOV)Avalanche Breakdown Diode (ABD)zener (avalanche) diode

Standard combination wave 8/20 I-Impulse & 1.2/50 V-ImpulseClamping voltage

Ir. H.P. Looi ([email protected] clamping device limits voltage transient to a specified level by varying its internal resistor in response to the applied voltage. The response of the clamping type device to a standard combination wave applied on the SPD by a generator is shown. The standard combination wave is defined as delivered by a generator that applies a 1.2/50 voltage impulse across an open circuit and an 8/20 current impulse into a short circuit. IEC (and IEEE) conventional for describing impulse consist of the first number which is the time (in microsecond) for the leading edge of the pulse to rise from 10% to 90% max. The second value measures the time taken to drop to mid-value (2dB) at the trailing edge of the pulse.

PQ-SPD, V1; February 201523SPD Technology Clamping Type

Clamping type (Voltage limiting) DeviceMust absorb the transient energy and therefore cannot withstand very high current levels.Subject to leakage currents, capacitive values may be higher than GDT.

Limits voltage transient to specified level by varying internal resistance in response to an applied voltage

Have quick response time.


PQ-SPD, V1; February 201524SPD Technology Clamping Zener DiodeABD or Zener (avalanche) Diode

Closet to an ideal V-clamp !

Fast response to rising potential.

Wide range of clamping volt-age (from 10V to 300V).

Ideal for low voltages, transients on data lines, power supply to computer buses, protection of IC from static.

Higher powered transient volage suppressors (TCS) using large junction zeners,Ir. H.P. Looi ([email protected] to the (relatively high leakage current (or high capacitance of the zener, care should be taken when applied ABD to R.F. circuits. IEC61643-321 specifies ABD.

PQ-SPD, V1; February 201525SPD Technology Clamping MOV

Metal Oxide Varistor (MOV)UVoltage variable resistor with sintered metal oxide (generally ZnO).

Handles higher peak at longer duration then diodes

Experience cumulative degradation with large current pulses.

Some engineer recommend fuse to be used with MOV to prevent large current surge from fusing/ damaging the sintered oxide.

Ir. H.P. Looi ([email protected]

PQ-SPD, V1; February 201526SPD Technology Crow BarStandard combination wave 8/20 I-Impulse & 1.2/50 V-ImpulseSudden switchingCrowbar type(Voltage switching)Gas Discharge Tude (GDT)Spark GapCarbon blockThryristor surge suppressorSilicon controlled rectifier (SCR)

Common Usage:Telecom terminal block (low energy)Lightning SPD high voltage switchgearO/H transformer spark gap.Ir. H.P. Looi ([email protected] response of the clamping type device to a standard combination wave applied on the SPD by a generator is shown.

PQ-SPD, V1; February 201527SPD Technology Crow BarCrowbar type (Voltage switching) DeviceLimits voltage transient energy delivered to the protected circuit by abruptly changing from a high impedance to a low impedance state in response to a rise in voltage level.

The crowbar device switches into conducting mode diverting the transient energy to ground or to dissipative circuits in the design. This allows higher withstand energy.

Have very quick response time.


PQ-SPD, V1; February 201528SPD Technology Clamping TypeSpark gap, GDT, carbon block

Air Gap 2 conductors placed at a separtion distance which will permit a arc to develop on a specified potential.Gap not enclosed.Sometimes installed as back-up to GDT.

GDT gap placed inside a seal tube filled with gas.Can withstand repeated surges, long lifeCan withstand very high current.Surges compared to other SPD.

Carbon block pair of carbon element separated by micro inch gap (.003-0.004)

IEC 61643-311Ir. H.P. Looi ([email protected] gaps and GDT are defined in IEC 61643-311

PQ-SPD, V1; February 201529SPD Technology Crow BarThryistor surge supressor (TSS)TSS Class of monolithic semi conductor devices incoporating diode, triodes or tetrode in configuration with switching/blocking functions in forward and/or reverse directions.

SCR silicon controlled rectifier; class of TSS with simple forward switching function.Conduction mode is triggered by a signal usually from a zener diode initiation is in response to surge.The SCR will continue conducting until the applied voltage drops to zero or to a specified value.

TSS have faster response time than GDT.Allow design for protection in both directions !

IEC 61643-341Ir. H.P. Looi ([email protected] are defined in IEC 61643-341

PQ-SPD, V1; February 201530SPD Technology SummarySummarised Comparison of Technologies


PQ-SPD, V1; February 201531Technology Combination SPD

Combination SPDCharacteristics of clamping combined with crow-bar.Resistors are added between terminals in multi-port devices.Capacitor/filters are sometimes added to modify behaviour of device.Ir. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201532Technology Combination SPD

Combination SPD

Ir. H.P. Looi ([email protected]

PQ-SPD, V1; February 201533Class by Test

Classification By TestUNIPOLAR PULSE (IEEE) Combination Wave (IEC61643)Up 6kV with 3kA (Maximum available destruction energy = 90 joules)1.2/50 Voltage Impulse8/20 Current Impulse

Ir. H.P. Looi ([email protected] test impulse defined in the IEC61643 Part 12 and Part 1. IEEE 62.41, 1999 also name the IEC combination wave as the unipolar pulse.The unipolar pulse is defined to mimic transient surge from lightning and some fast transient due to switching.


Classification By TestUnipolar Pulse 6kV with 3kA 90 joulesRingwave 6kV at 100kHz, 200A to 500A (depending on the location grade 2.6 joules to 6.5 joulesIEC61643 & IEEE62.41IEEE62.41 only

Ir. H.P. Looi ([email protected] IEEE 62.41 unfortunately also define a Ringwave as shown above. Obviously SPD tested only to the Ringwave will not comply with IEC requirement and may lead to confusion with regards to its usage in circumstances which may not be condusive due to its lower performance characteristics.Understanding the test specification is therefore important in the correct selection of SPD.


Classification By Test IEC61643-12Intended to sImulate partial conducted lightning current impulses.Recommended for locations of high exposure e.g. entrance to building etc.Class I TestClass IIClass III TestSubjected to impulses of shorter duration. Recommended for locations with lesser exposure to direct impulse.Ir. H.P. Looi ([email protected] of Class I, II & III with types of impulse wave are described in IEC61643-12 and IEC61643-1.

PQ-SPD, V1; February 2015Selection of SPDIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201537SPD Selection Procedure

Selection ProcedureRisk Analysis

Design/ Installation CheckSelection of SPD

Mode of protection, choice of location, classes coordination, protection zone concept etc.Need for SPD, determine energy withstand, risk / cost analysis.Ratings, specifications, interaction/ coordination with other devices (RCD, O/C etc.)Complete Roadmap to SPD design and selection in IEC 61643-Part 12Ir. H.P. Looi ([email protected] complete roadmap on the selection and design of SPD based on IEC 61643 Part 12.

PQ-SPD, V1; February 201538Selection of SPDRisk Analysis

Group A EnvironmentA1 Lightning incidenceA2 Power switching incidenceA3 Exposure and coupling with LPSA4 Location of facility of building Group B Equipment and FacilitiesB1 Equipment withstand category & immunity levelB2 Earthing systemB3 Power system layoutIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201539Selection of SPDRisk Analysis

Group C Economics and services interruptionC1 Service degradation or loss of servicesC2 Loss of operationC3 Repair or replacement of equipment or facilitiesC4 Emergency servicesGroup D SafetySafety risk to people /personnel.Group E Cost of ProtectionDesign of installationMaterial and devicesInstallation costIEC 61662 describes method for risk assessment related to lightning surge. Risk assessment for switching surge still under consideration by IEC.Ir. H.P. Looi ([email protected] 61662 describes method for assessing the risk related to surges due to lightning.A method for assessing the risk due to switching surges is under consideration by IEC.

PQ-SPD, V1; February 201540Selection of SPD

Design/ Installation Check6.1.2 Oscillation phenomenon6.1.1 Mode of protection and installation6.1.3 Connected lead length6.1.4 Need for additional protection6.1.5 Choice of the location of SPD depending on class of test6.1.6 Protection zone conceptInstall as close as possible to the origin of the installationInstall as close as possible to the equipmentConnecting conductors to SPD shall be as short as possibleSPDs at the entrance of the installation and others close to the equipmentClass I, II & III tests required at entrace, class II & III for locations close to the equipmentWhen such a concept is used SPDs should be installed at the zone boundaries.Note: The numbering correspond to the clause numbering in section 6 of IEC61643-12..Ir. H.P. Looi ([email protected] presentation


Design/ Installation Check Mode of ProtectionSPD BetweenTTTN-CTN-SITLine and neutralXXXaLine and PEXXXLine and PENXNeutral and PEXXXaLine to lineXXXXA When the neutral is distributed.Possible mode of protection for various LV systemsIr. H.P. Looi ([email protected] presentation


Design/ Installation Check6.1.2 Oscillation phenomenon6.1.3 Connected lead lengthUnder certain circumstances when distance between SPD and equipment is too large, oscillation may occur, leading to voltage rise at terminal of equipment LOAD RESONANCEInstall as close as possible to the origin of the installationLead length have influence due to their inductance.Preferred

PPAcceptable

PAvoid


PQ-SPD, V1; February 2015

Design/ Installation Check6.1.4 Need for additional protection6.1.5 Choice based on class of testSPD at entrance tested to class I.SPD nearer equipment test to class II or III.Additional SPD arises from analysis of source of surges, immunity levels of equipment and location in protection zone.SPD nearest equipment with V-protective level at least 30% below voltage withstand of equipmentIf SPD at entrance combine with distance from equipment lead to voltage below 0.8UW then additional SPD required.43Selection of SPDIr. H.P. Looi ([email protected] presentation

PQ-SPD, V1; February 201544Selection of SPD Lightning

Design/ Installation Check Zone of ProtectionPDS=power distribution systemLPZ= Lightining Protection System

Protection Zone according to IEC 61312Ir. H.P. Looi ([email protected] zone according to IEC 61312-1.

PQ-SPD, V1; February 201545Lightning Protection Zone, IEC 61312

Design/ Installation Check Zone of ProtectionLightning protection zoneOA subject to direct strike, unattenuated EM fieldOB not subject to direct strike, unattenuated EM fieldProtection ZonePZ1 subject to partial strike, conducted impulse reducedcompared to O zones.PZ2 remnants of impulse reduced compared to PZ1PZ3 surges caused by oscillation effects, magnetic field couplings, internal switching.Ir. H.P. Looi ([email protected] presentation

46Lightning IEEE 62.41PQ-SPD, V1; February 2015

Zone of Protection IEEE 62.41

Category ACategory BCategory COutlets and long branch circuits.All outlets at more than 10m (30ft) from Category BAll outlets at more than 20m (60ft) from Category CFeeder and short branch circuits.Distribution panel devices.Bus and feeder industrial plants.Heavy appliance outlets with short connections to service entrance.Lightning systems in large buildings.Outside and service entrance.Service drop from pole to building.Run between meter and panel.Overhead line to detached building.Underground line to well pump.

Ir. H.P. Looi ([email protected] zone specified by IEEE 62.41 is similar to IEC standard.

47Design Criteria IEC 61643-12PQ-SPD, V1; February 2015Selection of SPD

6.2.2 Protective distance6.2.1 Select Uc, UT, In/ IImp/ UDCLocation of SPD6.2.3 Prospective life & failure modeAcceptable ?6.2.4 Interaction of SPD with other devices6 Steps Design Criteria IEC61643-12Continue next pageIr. H.P. Looi ([email protected] are selected after design criteria based on six steps.

PQ-SPD, V1; February 201548Design Criteria IEC 61643-12Selection of SPD

6.2.4 Interaction of SPD with other devicesNormal ConditionsChoice of voltage protection levelIC shall be safe!Fault ConditionsSurge coordin-ation between SPD & O/CCoordination with other SPDSPD shall not intefere with RCD or CBCheck In for O/C operation.Take into account:Surge withstand of equipmentNominal voltage of systemWhen two SPDs are used on the same conductorFrom previous pageIr. H.P. Looi ([email protected] You for Your Attention

Planning An Urban Transition Sustainability Benchmarks

Ir. Dahari Mat Siran ([email protected])B.Eng (Hons), Power Quality WorkshopModule PQ Transient & Surge Protection


power quality and surge

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