Schneider Electric PM5300 manual Power quality, Harmonics overview, Harmonic content calculations

Page 89

PowerLogic™ PM5300 series user guide

Chapter 11—Power quality

 

 

Chapter 11—Power quality

This section describes the meter’s power quality features and how to access power quality data.

The meter measures voltage and current harmonics up to the 31st harmonic, and calculates Total Harmonic Distortion (THD) and Total Demand Distortion (TDD and tdd).

Harmonics overview

Harmonics are integer multiples of the fundamental frequency of the power system. Harmonics information is valuable for power quality analysis, determining properly rated transformers, maintenance and troubleshooting.

Harmonics measurements include per-phase magnitudes and angles for the fundamental and higher harmonics relative to the fundamental frequency. The meter’s power system setting defines which phases are present and determines how line-to-line or line-to-neutral voltage harmonics and current harmonics are calculated.

Harmonics data provide information to determine how non-linear loads affect the power system. For example, power system harmonics can cause current flow on the neutral conductor, increase heating in electric motors, and eventually damage connected equipment. Power conditioners or harmonic filters can be used to minimize unwanted harmonics.

Total Harmonic Distortion and Total Demand Distortion

Total Harmonic Distortion (THD) is a measure of the total per-phase voltage or current harmonic distortion present in the power system. It provides a general indication of the quality of a waveform. THD is calculated for each phase of both voltage and current.

Total Demand Distortion (TDD) is the per-phase harmonic current distortion against the full load demand of the electrical system. TDD indicates the impact of harmonic distortion in the system. For example, if your system is showing high THD values but a low demand, the impact of harmonic distortion on your system might be insignificant. However at full load, the THD value for the current harmonics is equal to TDD, so this could negatively impact your system.

The meter uses the following series of equations to calculate THD and TDD.

Harmonic content calculations

1. Calculate harmonic content (HC).

HC = (H2)2 + (H3)2 + (H4)2…

HC (harmonic content) is equal to the RMS value of all the non-fundamental harmonic components in one phase of the power system.

2. Calculate the harmonic content for current (HCI).

HCI = (HI2)2 + (HI3)2 + (HI4)2…

HCI (harmonic content current) is equal to the RMS value of all the non-fundamental current harmonic components (HI2…HIn) in one phase of the power system.

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Contents PowerLogic PM5300 Series Power and Energy Meter Page Please note Important InformationPage Hardware Refer Introduction Chapter Safety Precau TionsEnce Chapter Multi-tariff feature Chapter AlarmsChapter Power quality Chapter Input / OutputChapter Maintenance Chapter Meter resetsUpgrades Chapter Verifying accuraPowerLogic PM5300 series user guide Parts and Accessories Power and Energy Meter HardwareBox Contents IntroductionPowerLogic PM5300 user guide Before You Begin Safety PrecautionsPowerLogic PM5300 series user guide Functions and Characteristics Models, Features and OptionsPM5300 Series Models, Features and Options Functions and CharacteristicsEnergy Values Power Quality MeasurementsDemand Values Other MeasurementsElectrical Characteristics Technical SpecificationsEnvironmental Characteristics Mechanical CharacteristicsSafety Electromagnetic CompatibilityHuman Machine Interface Safety precautionsDimension Mounting the PM5300 Meter mountingMeter wiring Screw driver type M3 Serial No Description SpecificationMake Part code Description Recommended cablesWiring Diagrams Symbol Description Power systemCurrent Transformer Voltage disconnect switch Direct connect voltage limitsSymbol Power system setup parameters Power system descriptionMeter setting Voltage input protection Voltage and current input wiringCurrent input protection Direct connect maximumCommunications Control power wiringBalanced system considerations Serial communicationsRS-485 network configuration RS-485 wiringRS-485 cable RS-485 maximum cable lengthEthernet wiring EthernetETHERNET SwitchSWITCH/ hub/ HUB Ethernet configurationDigital outputs Ethernet communicationsRelay outputs Status inputsDigital output connections Status input connectionsRelay output connections LED indicators Front panel display and meter setupAlarm / energy pulsing LED modes Heartbeat / communications LEDRelated topics Notification iconsMeter screen menus PM5300 display screen menus Menu treeMeter setup screen navigation Front panel meter setupConfiguring the basic setup parameters Basic setup screenParameter Values Description Basic setup menu treeBasic setup parameters Setting up serial communications Communications setupSerial communications setup menu tree Communication portsEthernet communications setup menu tree Setting up Ethernet communicationsCommunications setup parameters Setting up the display HMI settingsEthernet port settings Display setup menu treeSetting up regional settings Setting up the screen passwordsDisplay setup parameters Regional settings menu treePassword setup parameters Lost passwordPassword setup menu tree Clock setup menu tree Setting the clock Advanced setupClock setup parameters Advanced setup menu treeAdvanced setup parameters Setting up the alarm / energy pulsing LEDAlarm / energy pulsing LED settings menu tree LED setup parameterPower or current demand setup parameters Input / output setup Demand setupDemand setup menu tree Remote Meter Setup Multi-tariff setupAlarms setup Viewing meter data from the front panel Viewing Meter DataMeter data display screens Displaying data screensVolts U-V Power PQSHarm Energy EHz F AlarmUnbal MnMxUsing software to view meter data Using ION Setup to view or modify configuration dataTimer MaintStatus Input, Digital Output Ports and Relay Output Ports Input / OutputStatus input applications Configuring status inputs using ION Setup Status input setupNavigate to I/O configuration I/O Setup Status input setup parameters available through ION SetupStatus input setup menu tree Configuring status inputs using the front panelDigital output wiring example Digital output setupDigital output applications Digital output application exampleDigital output setup parameters available through ION Setup Configuring digital outputs using ION SetupDigital output setup menu tree Configuring digital outputs using the front panelOn Time s This defines the pulse width on time in seconds Parameter Values Description Configuring relay outputs using ION Setup Relay output setupRelay output setup parameters available through ION Setup Relay output applicationsSet to External or Alarm. The relay output Relay output setup menu tree Configuring relay outputs using the front panelAlarm / energy pulsing LED setup Navigate to I/O configuration Energy Pulsing Disabled turns off the LED completely Second Alarms AlarmsAbout Alarms Alarm List of Standard 1-Second Over/Under AlarmsHow the power meter handles setpoint-driven alarms Digital AlarmsUnary Alarms Alarm SetupAlarm Priorities Using an Alarm to Control a Relay and Digital OutputSetting Up 1-Second Alarms Setting Up 1-Second Alarms Setting Up Unary Alarms Setting Up Digital Alarms Setting Up Digital Alarms Viewing Active Alarms and Alarm Counters Viewing Alarm Activity and HistoryViewing Unacknowledged Alarms and the Alarm History Log PowerLogic PM5300 series user guide Alarms Description Number of Registers Data Type Register Number Data LogsData Logs Memory Allocation for Log Files Alarm LogAlarm Log Storage Measurements and calculations Power factorReal-time readings EnergyPower factor sign convention Power factor min/max conventionIEC mode Power factor minimum and maximumIeee mode Power demand calculation methodsDemand Block interval demandBlock interval demand example Synchronized demandPredicted demand Current demandThermal demand Thermal demand examplePredicted demand example Peak demandMulti-tariff feature overview Multi-tariff featureMulti-tariff feature example Time of day mode overview Command mode overviewTime format Front panel date and time formatConfiguration 1 four tariffs with weekdays and weekends Example tariff configurations for a four-tariff systemTariff creation method Tariff Type Start date End date Start time End timeConfiguration 1 2 tariff assignment using 2 digital inputs1 Input mode overviewConfiguration 2 2 tariff assignment using 2 digital inputs Digital input requirements for required number of tariffsConfiguring time of day mode tariffs using the front panel Configuring tariffs using the front panelTariff setup menu tree Time of day mode tariff setupConfiguring input mode tariffs using the front panel Harmonic content calculations Power qualityHarmonics overview Total Harmonic Distortion and Total Demand DistortionDisplaying harmonics data Viewing harmonics using the front panelTHD and thd calculations TDD calculationPower Quality display screen Viewing THD/thd using the front panelViewing TDD Example 13th to 21st harmonics for line-to-neutral voltageRelated topics Accuracy test requirements Testing overviewVerifying accuracy Energy pulsing Reference device or energy standardLocation of energy pulsing LED PM5300Verifying accuracy test Calculating the number of required pulses Calculating total powerPercent error calculation Total power limit for digital output Total power limit for alarm / energy LEDEnergy pulsing considerations VT and CT considerationsTest points Typical sources of test errorsWatt-hour test points example Var-hour test points exampleFront panel meter reset screens Meter resetsGlobal resets Reset menu treeSingle reset options Single resetsAlarm counter options Alarm counter Option DescriptionPowerLogic PM5300 series user guideChapter 13-Meter resets 102 Password Recovery Maintenance and UpgradesPower Meter Memory Identifying the Firmware Version, Model, and Serial NumberAdditional Meter Status Information Control PowerDownloading Firmware Meter105 TroubleshootingHeartbeat/Comms LED Potential Problem Possible Cause Possible Solution TroubleshootingGetting Technical Support Register List 106MID Compliance Specifications relevant to MIDMID overview MID compliance for the meterMID Compliance Installation and wiringPM5331/PM5341 default screen Installing the terminal coversDefault PM5331/PM5341 display screen Location of terminal coversLock-protected setup parameters MID-protected setup parametersLock-protected setup parameters Meter firmware versionInitializing the meter Setting up the PM5331/PM5341Locking or unlocking the meter Setting up lock passwordNavigate to Maint Setup Meter Lock 113 GlossaryTerms 114 115 Abbreviations116 117 118 Page Schneider Electric 35, rue Joseph Monier CS
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