25analizzatori di pq (power quality) e pmu (phasor measurement unit) basati su tecnologia ni per...

7/29/2019 25Analizzatori di PQ (Power Quality) e PMU (Phasor Measurement Unit) basati su tecnologia NI per monitoraggio e analisi di Smart Grid

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Dr. Daniel KaminskELCOM, a.s.

Division of Virtual Instrumentation

NI based PQ (Power Quality) Analyzers and PMUs (Phasor Measurement Units) for Smart Grids Monitoring and Analysis


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PresentationAgenda

Few facts about ELCOM What is Power Quality ELCOM Solutions for Power Quality Analyzers ELCOM Solutions PMUs Applications


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ELCOM Facts Sheet

Founded in 1990 Based in Czech Republic 150 employees Annual revenue 16mil Core business is electrical engineering

and test & measurement


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ELCOM Products & Services

Turnkey Solutions and Products

Functional TestersPower Quality Analyzers, PMUsLean Assembly Lines

Electrical DrivesSpecial Power SuppliesPower Filters and Compensators

Custom SolutionsLaboratory Automation

Test & Measurement Software DevelopmentSpecial Electronic and Mechanical Components


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17 years of PQ Analyzers development at ELCOM

From the very beginning till now theinstrument firmware is fully written inLabVIEW

From the very beginning till now the NIDAQ boards are used (ISA, PCI, USB)

From the very beginning till now weproduce PC-based PQ analyzers In 2005 we started to use cRIO and later

sb-RIO platform also


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History of PC based PQAs


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ENA510 Latest Model of Portable PQA/PMU

Portable analyzer with twothree-phase voltage/currentsystems and embeddedtouch screen

8 voltage inputs up to 600 VRMS; 8 current inputs usingcurrent clamps; 4,2kVisolation

16 digital inputs, externalGPS receiver

Uses two NI sbRIO-9612 andone industrial PC with display

Works as PQ meter and PMUtogether


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From PC-based PMU to sbRIO based PMU

ENA440

ENA450

ENA460


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ELCOM sbRIO based PQA ENA460

NI sbRIO 9612 based DIN rail mountable Sampling rate 12kS/s 4 voltage inputs

75/150/300/600V, 4.2kV

isolation, 600kOhm

4 current inputs 1A, 5A, 4.2kV isolation barrier

0.1% TVE precision

8 digital inputs

Up to 16 GB of CF data storage


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ENA450 HW

Basic configuration:9076 400MHz92259227

Full configuration:9023 Controller9114 8-slot chassis922592279422 DI


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ELCOM-made modules for cRIO

4x U 300Vrms, 4x I 1/5Arms, overcurrent 6/15A contin., 20/100A 1sec 4.2kV isolation barrier GPS / GLONASS receiver


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PQA SW Components

ENA-Node is the firmware of PQanalyzer.

ENA-Touch is the PQ analyzer userinterface.

ENA-Report is tool for off-line processingof stored data.


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ENA-Node = ENA450 firmware

Measurement service, which makes all dataacquisition, calculation, storing andcommunication.

Available functionality:FFT analyzer (full bundle)Vector analyzerPower Flow monitorFlickermeterEN50160 Voltage monitorPower Network Impedance analyzerHalf-period RMS monitor

Transient Recorder (9.6kS/sec stored) (full bundle)

Voltage Telegrams & Alarms (full bundle)Digital Inputs (full bundle)


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ENA450 SW Deployment


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ENA-Touch = ENA450 User Interface


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ENA-Report


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Electrical Power is a specific Product

Electricity is an unusual commodity because itis required as a continuous flow.

it cannot be easily stored in a ;quantityit cannot be subject to quality checks before it is used.

Electricityis generated far from the point of useis fed to the grid together with the output of many othergeneratorsarrives to the point of use via several transformers andmany kilometers of overhead lines and cabling.


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Power Quality

Electricity can be looked upon as a product,like any other convenience provided.

Therefore, electrical power has to complywith specific quality requirements:

230 Vrms (or different)AC sinusoidal

50Hz3 phasesPermanent availability


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PQ Issues Across the Power System

GenerationInteraction with close coupledloadsHarmonics from loads

Transmission and Sub-T

U Sags propagationCapacitor switching transientsLighting transientsExcessive current harmonics

U harmonicsFlickerUnbalance

Distribution FeedersSame like Transmiss. and Sub-TCourtesy of EPRI


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PQ Issues Across the Power System

End user Inrush currentsGroundingStray VoltageRESD technologiesElectromagneticInterference/Fields (EMI/F)Radio Frequency Interference(RFI)

Overarching IssuesPHEV and renewablesSmart GridEnergy Efficiency

Courtesy of EPRI


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Voltage Disturbances

Voltage on the generator

terminals is ideal Current causes voltage

drop on any impedance onthe way from generator tothe load

Voltage drop shapecorresponds to the currentshape

Resulting voltage U=E ZI Voltage disturbance is

caused by non-sinusoidal

currents

~

Load with high

current harmonics

I (current)

Other loads

Z(impedance

of

TS,

DS)

E

(generator)

U = E Z I

E


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Electrical Energy Transmission with PQ Monitoring


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Power Quality Problems

Whether or not the customer is likely tosuffer from power quality problems dependson:

The quality of voltage supplied by electricitysupplier

The types of loads in customer s installation The sensitivity of customers equipment tovarious kind of disturbances

There is not single, generic solution of PQproblems. An optimum solution needs to be

designed for each site, taking into accountthe above three factors.


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Examples of Financial Loss due to PQ

(*) European Copper Institute, European Power Quality Survey, 2002


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Power Quality Phenomenas

Voltage dips

Voltage interruptionsVoltage swellsVoltage transients

Voltage fluctuationHarmonics + interh.Voltage unbalance

FlickerSignaling voltagesFrequency fluctuation

electromagneticreactions


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Voltage events categories

Voltage sag/dipU bellow 90% of Un, but not bellow interr.

Voltage interruptionU bellow 1% - 15% of Un

Voltage swellU above 110% Voltage transient (switching overvoltage)

On much higher than fundamental frequency


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Voltage dips

Voltage dip is a sudden

reduction of the voltage,followed by voltagerecovery after a short

period of time. Characterized by: Time of startDepth or residual voltageDuration

Duration from one periodof fundamental


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Voltage swells

They occur at power frequency 50Hz

They have various origins Earth fault in isolated neutral system orimpedance earthed neutral system voltage of the healthy phases can reach the phase tophase voltage

Ferroresonance in circuits containing acapacitance and saturable inductance

Break of neutral conductor Overcompensation Faults on alternator regulators or tap changer

transformer


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Rapid voltage changes

Amplitude changes within range Un 10% RVCH causes flicker.


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Harmonics and inter-H

Harmonics are mainly

produced by non-linearloads PQA calculates each Tw the

FFT for U signals

Frequency domain step: Harmonics 50Hz Interharmonics 25Hz

Each particular harm. orinterharm. has definedcertain limit in % referencedto Un (not to thefundamental harmonic)

~

Load with high

current harmonics

I (current)

Other loads

Z

U = E Z I

E

f

f

U

U


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Harmonic Distortion

Total HarmonicDistortion is ratio of sumof all harmonics RMSvalues to RMS value of

fundamental wave(50Hz)

In standards the THDhas defined compatiblelimit in %

1

2

2

U

U

THDu

N

==


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Voltage unbalance

A 3-phasesystem isunbalanced if:

the rms values of the phasevoltages are notequal

the phase anglesbetween phasesare not equal

both of them


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Flicker

Definition: Impression of unsteadiness of

visual sensation induced by a light stimuluswhose luminance or spectral distributionfluctuates with time.

-400

-300

-200

-100

0

100

200

300

400


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Flicker Pst, Plt

Chain: lamp eye brain = flickermeter IEC61000-4-15Depends on:

frequency of voltage changes

depth of voltage changestype of lamp: incandescent lamp, energy saving lamp, LEDsFlicker is represented by:

Pst...short term (10 min)

Plt...long term (2hours)

A flicker severity level of 1 corresponds to a flicker level that irritates 50 % of the test persons and is defined as the threshold of irritability.


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Signaling Voltages

Sometimes called ripple signal Signal voltages are superimposed on thefundamental frequency by DSO The reason is remote control of big loads etc. over

power network in some countries. Allowed amplitude depends on the frequency

according to the defined curve


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Frequency of the power system

Frequency of the power system will vary as loadand generation change.

In the whole interconnected grid has to bebalance between electricity generation andconsumption


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Frequency limits in EU

10sec-mean values are evaluated 95% measured values over a week should be 50Hz 1%

stand alone power network: 50Hz 2% 100% measured values over a week should be 50Hz +4%/-6%

stand alone power network: 50Hz 15%


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Agregation time intervals

3 seconds:Signalling voltages

10 seconds:Power Frequency

10 minutes

Urms,Harmonic+interharmonic voltagesVoltage unbalanceFlicker Pst

2 hoursFlicker Plt

Basic observation interval for measurement evaluation according toEN50160 is one week


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IEC61000-4-30 Ed.2 (2008)

Defines the methods for measurement andinterpretation of results for power quality parameters in50/60Hz AC power supply systems.

Measurement methods are described for each relevanttype of parameter in terms that will make it possible toobtain reliable, repeatable and comparable results

regardless of the compliant instrument being used andregardless of its environmental conditions.


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IEC61000-4-30 Ed.2 (2008)

IEC61000-4-30

is a performance specification, not a designspecification.gives measurement methods but does not set

thresholds. The effects of transducers (VT, CT) being inserted

between the power system and the PQA are

acknowledged but not addressed in detail in thisstandard.


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Classes of measurement methods

According to IEC61000-4-30 Ed.2 Class AUsed where precise measurement are necessary. E.g. forcontractual application to resolve disputes.

Class SProcessing requirements and price of the instrument are lower.

Class B

Obsolete. The weakest requirements. Not recommended fornew designs.


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Other standards for PQA

IEC61000-4-30 Ed.2 contains two links to anotherstandards:

IEC61000-4-7 in connection with voltage harmonicsmeasurementIEC61000-4-15 in connection with Flickermeasurement


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IEC61000-4-15 Ed.2 (2010)

Flickermeter functional and design specifications

IEEE 1453: Recommended PracticeAdoption of IEC 61000-4-15:2010


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EN 50160

EN 50160 is not IEC, but CENELEC standard

EN50160 function is to give values for the main voltagecharacteristics of electricity supplied by publicnetworks.

Defines the electrical product for HV, MV and LV

system giving the voltage characteristics which can beexpected at the supply terminals.


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EN 50160


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IEEE 1159Recommended Practice for Monitoring Electric Power Quality

Working Group for Power Quality Monitoring formedin nearly 20 years ago in response to a need forstandardizing power quality monitoringmanufacturing industry and the use of these

monitors in the field by utilities and end-users.

IEEE 1159 contains:

Consistent terminologyDefinitionsApplications

Data interpretation


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1599 x 61000 Differences

IEEE 1599

Not enforced, justinformative,tutorial, instructive

Developed byvolunteers

Approved byconsensus

IEC 61000 series

Adopted and enforcedas national standards force of law. Very

careful drafting Developed by

assigned nationalexperts

Approved by nationalvoting

Courtesy of PowerStandards.com


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Biggest ENA Installation

CEZ - Distribution Network Operator45 multi-system PQAs, 146 monitored 3~ systems42 single-system PQAs

E.ON Czech Republic34 single-system PQAs

CEPS - Czech Transmission Network Operator35 PMUs

SEPS - Slovak Transmission Network Operator36 single and multi system PQAs, 54 monitored 3~ systems2 portable PMUs, 8 PMUs for fixed installation


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Synchronous Phase Measurements


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What Is Phasor Measurement

Grid stability becomes more fragile/important as distributedgeneration increases as well as cross-border energy transfers

Grid operator uses phase angle and amplitude (phasor) acquiredat various points of the grid AT THE SAME TIME to determine gridstability

Based on phasor values operator can take action to preventunstable operation or even blackout

Instrument to measure phasors is called Phasor MeasurementUnit, sometimes is coupled with protection relays

IEEE C37.118 defines requirements to be met by phasormeasurement units


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Why to Measure Synchronous Phase

The phase position of AC voltages and currents in

different parts of an electric power system determinesthe stability and the dynamic performance of thesystem .

PMUs are used for Wide Area Monitoring Systems(WAMS). The WAMS supports utilities in makingoptimal usage of the transmission grid capacitywith regard to active power flow and voltage profile.

Real-time information from WAMS gives earlywarning of power system disturbances that, if leftunattended, could cascade into system wideblackouts


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PMU Standardization

PMU must meet IEEE Std C37.1182005

This standard covers synchronized phasor measurement inelectric power systems, defines steady state performanceand data transmission format for real-time reporting

New released standards:C37.118.1 definition of 2 types of PMU classes: P protection andM measurement/monitoring with regard to reporting latencyincluded definition of dynamic behavior requirements

C37.118.2 description of communication protocol Testing, calibration, installation guides IEEE PC37.242


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WAMS Customer

- Czech TSOHV Lines Length:

400 kV 2 979 km220 kV 1 371 km

Domestic production approx. 10 GW consisting of:

57%

32%

5%3%2%

1%

Solid FuelsNuclearGas

WaterPhotovoltaicWind


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Project Description

Wide Area Monitoring System installationand commissioning

Number of PMUs: 39

Reporting Rate: 50 Hz WAMS Central Server located in Prague

Only part of the grid covered


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Grid Areas Covered by WAMS


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Wide Area Monitoring System

WAMS Operator Interface

Psymetrix PhasorPoint Client

WAMS Central ServerHW: DELL PowerEdge PE720XDSW: Psymetrix PhasorPoint Server Application

Phasor Data Concentrators (PDCs)HW: iEi ECW, OS Linux DEBIANSW: Psymetrix PhasorPoint PDC

Phasor Measurement Units (PMUs)ELCOM ENA460 PMU


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Thank you for your attention !

Questions?

www.elcom.cz/en/www.power-quality.eu/

www.elcom.cz/en/virtual-instrumentation/
http://www.elcom.cz/en/http://www.power-quality.eu/http://www.elcom.cz/en/virtual-instrumentation/http://www.elcom.cz/en/virtual-instrumentation/http://www.power-quality.eu/http://www.elcom.cz/en/

25analizzatori di pq (power quality) e pmu (phasor measurement unit) basati su tecnologia ni per...

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