IEEE and IEC Harmonic Limits

Sezione di Roma

SEMINARI SULLA QUALITA’ E SULLA SICUREZZA ELETTRICA

IEEE and IEC Harmonic Limits

Il Dipartimento di Ingegneria Elettrica dell’Università di Roma “La Sapienza”, nell’ambito del corso di Distribuzione ed Utilizzazione dell’Energia Elettrica, l’AEIT – Sezione di Roma, la Commissione Elettrica dell’Ordine degli Ingegneri di Roma e l’IEEE-IAS Chapter del Centro-Sud Italia hanno organizzato presso l’Aula 40 della Sapienza – Università di Roma Dipartimento di Ingegneria Elettrica, Facoltà di Ingegneria, il seminario

Mark Halpin Auburn University 21 May 2007

Harmonics in electrical power systems Prof. Ing. Mark Halpin, professore di Electrical Power Systems dell’Auburn University - Alabama USA presidente dell’IEEE/IAS, fellow IEEE

Coordinatore : Prof. Ing. Giuseppe Parise

Limits on Harmonics in Power Systems • IEEE Standard 519 “Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems” suggests limitations for voltage and current harmonic contamination – individual harmonic limits – total harmonic distortion limits

• Other standards are different and should be consulted for systems and equipment manufactured or applied outside the U.S. – IEC 61000-3-2, 3-12 (and others): LV equipment standards – IEC 61000-3-6: MV/HV/EHV “system” standard – IEC 61000-4-7 and 4-30: Harmonic measurement standards

• IEEE 519 and IEC 61000-3-6 have the same goal but utilize different conceptual approaches

519 Limits on Harmonics in Power Systems • IEEE 519 considers the “point of common coupling” (PCC) as the customer-utility interface point – Harmonic current limitations for end-users apply at this point – Harmonic voltage limits apply throughout the utility network and are suggested at the PCC to insure quality in the voltage supplied

• “Shared Responsibility” requires compromise from owner/operators and users – Voltage limits set to avoid problems – Current limits chosen based on equity between • Owners/operators and users • Users and users

IEEE vs. IEC Harmonic Standards • IEEE does not have equipment standards • Fundamental IEEE philosophy is “shared responsibility” – Limit users to an equitable current emission level • Users may not create undesirable resonance conditions

– Utility companies must control system resonances to limit voltage distortion • Fundamental IEC philosophy is “voltage quality maintenance” – Users may not inject harmonic currents that lead to excessive voltage harmonic production – Utility (supply) system characteristics are defined by system requirements and are not manipulated to allow greater user harmonic currents

IEEE 519: Limits on Voltage Harmonics • Voltage harmonic limits are suggested for both individual harmonics and total harmonic distortion. Different limits apply for different voltage levels Voltage Harmonics Voltage at PCC 161 kV

Individual Limit 3.0 1.5 1.0

THD 5.0 2.5 1.5

IEEE 519: Limits on Current Harmonics • Limits are provided for individual harmonics and THD (TDD) for general distribution systems. All values are in percent and based on a 15 or 30 minute demand interval

IEEE 519: Limits on Current Harmonics • For higher voltage levels, lower percentages of harmonic contamination are permitted Harmonic Current Limits: 69-161 kV Systems

Harmonic Current Limits: 120-69000 V Systems Current Ratio 1000

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