Measurement of phase angles of voltage and current harmonics Dr. Michael Schwenke, EM DG PRO D PA © Siemens AG 2016 siemens.com Measurement of phase angles of voltage and current harmonics 1. Harmonics: cause – impact – measurement - countermeasures 2. Related standards/measurement methods 1. IEC 61000-4-7: General guide on harmonics and interharmonics measurements and instrumentation 2. IEC 61000-4-30: only PQ measurement methods for harmonic/interharmonic magnitudes are defined Harmonic subgroup and Interharmonic centered subgroup acc. IEC 61000-4-7/IEC 61000-4-30 3. Goal of measurement and applications 1. Prevailing phase angle, variation factor and prevailing ratio PR 2. Sign of harmonic active power 3. Improved power measurement 4. Implementation in SICAM Q100 5. Example © Siemens AG 2016 Page 2 04/2016 Dr. Schwenke / EM DG PRO D PA Power Quality What to Do? - The ABC Approach • Ensure that the obtained energy is according to a defined quality. • Ensure that negative influences to the connected power supply network are within a certain limit. A Measure • Continuous measurement of relevant parameters at important points in the power supply network: • Point of coupling: In-feed from the utility • Transformer feeders • Point of coupling of specific production units/lines B Evaluate • Concentrate, analyze and evaluate recorded parameters: • Assigning data to the point where they are measured • Evaluate data according to necessary limits and criteria (e.g. EN 50160) • Big loads causing disturbances • Identification of trends, deviations and limit value violations together with the duration and value • Use of standardized measurement methods (Class A, Class S) • Assigning evaluation results to the related points C Optimize • Definition of proper mitigation measures: • Dedicated energy supply contract with a defined level of Power Quality • Filters, redundancies etc. • Process optimization • Use of less sensitive devices and equipment • Identification of possible originator of the disturbance © Siemens AG 2016 Page 3 04/2016 Dr. Schwenke / EM DG PRO D PA Harmonics What to Do? • Caused by: power electronic devices, UPS, converter drives, rectifier, fluorescent lamps, power supply for IT equipment, PV and wind power inverters • Impact: heating of motors, cables, transformers; malfunction of breakers, relays, PLC communication, resonances A Measure B Evaluate C Optimize • (Active) harmonic filter àreduce impact on neighborhood equipment • power factor correction à Improve energy efficiency U = 230 V I = 160 mA Total Harmonic Distortion THD U: 2 % THD I: 190 % © Siemens AG 2016 Page 4 04/2016 Dr. Schwenke / EM DG PRO D PA Applications of phase angle information Goal Analysis of harmonic power flow Analysis of prevailing phase angles Measurement “relative” phase angle: · measurement of phase angles between harmonic voltages and currents (same order number) · Evaluation of harmonic flows throughout the system · Assignment of responsibilities in the system through the identification of harmonic sources and harmonic sinks · Calculation of active, reactive and apparent powers “absolute” phase angle · phase angle in relation to the voltage fundamental Applications · · · · Assessment of harmonic current measurements in different points in the system Assessment of summation factors of harmonic currents from different disturbing loads when they are connected to the same node Modeling of disturbing loads and evaluation of their disturbing effect Design of countermeasures for disturbing loads © Siemens AG 2016 Page 5 04/2016 Dr. Schwenke / EM DG PRO D PA Prevailing phase angle, variation factor and prevailing ratio Prevailing phase angle: aggregation of phase angles over time (e.g. 10 min) Variation factor VF Prevailing ratio: PR = 1 - VF © Siemens AG 2016 Page 6 04/2016 Dr. Schwenke / EM DG PRO D PA Philips ML 100: High-pressure mercury tube in series with a tungsten filament Voltage/current of 100 pcs. © Siemens AG 2016 Page 7 04/2016 Dr. Schwenke / EM DG PRO D PA Example voltage/current characteristics and harmonics © Siemens AG 2016 Page 8 04/2016 Dr. Schwenke / EM DG PRO D PA Harmonic measurement: Magnitude, phase angle, Prevailing phase angle, Prevailing angle ratio Voltage phase A Current phase A © Siemens AG 2016 Page 9 04/2016 Dr. Schwenke / EM DG PRO D PA Example voltage/current charcteristics Harmonic direction detection: sign of harmonic active power © Siemens AG 2016 Page 10 04/2016 Dr. Schwenke / EM DG PRO D PA Improved power calculation Reactive power for phase p, quadrature phase shift formula Reactive power for phase p, Budeanu’s harmonic definition Qp = Qpquad 1 M -1 = × å (vpk - N / 4 ´ ipk ) M k=0 Qp = Qpharm = hmax åI i=1 i, p × Vi, p × sin(j i, p ) © Siemens AG 2016 Page 11 04/2016 Dr. Schwenke / EM DG PRO D PA Contact page Dr. Michael Schwenke Senior Key Expert Power Quality EM DG PRO D PA Wernerwerkdamm 5 13629 Berlin Phone: +49 30 38620136 Mobile: +49 162 1325063 E-mail: michael.schwenke@siemens.com siemens.com © Siemens AG 2016 Page 12 04/2016 Dr. Schwenke / EM DG PRO D PA