Choosing the Right Instruments for Power Quality Measurements - Prof. Paul E. Ortmann, Study notes of Electrical and Electronics Engineering

Download Choosing the Right Instruments for Power Quality Measurements - Prof. Paul E. Ortmann and more Study notes Electrical and Electronics Engineering in PDF only on Docsity! 1 ECE 528 – Understanding Power Quality Paul Ortmann portmann@uidaho.edu 208-733-7972 (voice) 208-736-3248 (fax) http://www.ece.uidaho.edu/ee/power/ECE528/ Lecture 42 1 Lecture 42 2 Today… • Power quality instruments and analyzers – Safety first – The basic tools 2 Lecture 42 3 Instruments and analyzers Safety First • Why is safety even more important in power quality work? – Maintenance and construction work is nearly always done with systems de-energized – lock-out/tag-out – Power quality work requires the equipment to be energized while measurements are made – Qualified Person (2008 NEC) One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. • Specific safety practices and requirements are outside the scope of this class Lecture 42 4 Safety First • The hazards – Electrical Shock • Results from contact allowing current flow through the body • May result in fibrillation – Burns • contact – current • Flash – radiant – Impact • Blast energy and shrapnel 5 Lecture 42 9 Basic instruments • DMM – Digital multimeter – Single-phase, single parameter instrument – Typically True RMS – May include built-in current clamp, or use external clamps – May measure other parameters • Frequency • Capacitance • Resistance • Crest Factor Lecture 42 10 The next step up Handheld power quality analyzers • Measures voltage and current simultaneously • Power factors, power values – Additional functions • Sags, swells • Transients • Inrush current • Harmonics – Voltage and current, THD, individual harmonic magnitudes, etc. • Basic oscilloscope functions – Some basic recording capabilities – Will save data for analysis and reporting 6 Lecture 42 11 Handheld power quality analyzers Some function examples Lecture 42 12 Handheld power quality analyzers Looking at the data with a computer 7 Lecture 42 13 Handheld power quality analyzers • Single-phase (2-channel) – (1 voltage and 1 current channel) • Three-phase (8-channel) – (4 voltage and 4 current channels) – Adds automatic calculation of three phase parameters • Voltage imbalance, three-phase power, etc. • Connections become important • On-screen connection diagrams are helpful Lecture 42 14 Sample setup diagram • A useful feature in three-phase instruments From Fluke Inc.