Manila Electric Co. · PSE:MER
Manila Electric — Technical Presentation (November 2017)
28 slides from Manila Electric's technical presentation, November 2017
Slide 1: Understanding Power Quality
Understanding Power Quality
Slide 2: Outline
Outline I. Power Quality (PQ) Definition II. Distribution Utility Parameters & Limits III. Types of PQ Problems IV. Solution to PQ Problems
Slide 3: Power Quality (PQ) Definition
Power Quality (PQ) Definition The quality of the voltage, including its frequency and the resulting current, that are measured in the Distribution System during normal conditions
Slide 4: Power Quality (PQ) Definition
Power Quality (PQ) Definition PQ is all about electromagnetic compatibility • Equipment operates within its environment without causing disturbance either to itself or other equipment, or back to utility source • End-use equipment (load) rating matches supply voltage rating and variations • Mismatch
Slide 5: Power Quality (PQ) Definition
Power Quality (PQ) Definition PQ is all about electromagnetic compatibility • Utility service standards must be considered before purchase of end-use equipment for compatibility of ratings • A mismatch is costly in terms of bridging incompatibility
Slide 6: Parameters and Limits
Parameters and Limits Power quality begins with knowing the characteristics of the distribution utility, its capabilities and limitations. Customers must take note of the following parameters in determining the appropriate equipment and system design for their facilities. Parameter Limit/s Frequency
Slide 7: Parameters and Limits
Parameters and Limits Effect of Utility Variations on Equipment Ratings Equipment must operate satisfactorily within the -10% to +10% voltage variation of the Distribution Utility's nominal service voltage Voltage Variation Lower Limit Upper Limit Nominal Service Voltage: 230 V 207 volts -10% 253 vo
Slide 8: PQ Problem Illustrated
PQ Problem Illustrated A Failure Normal Failure B C
Slide 9: PQ Problem Illustrated
PQ Problem Illustrated Fault/s anywhere in the network may result to power disturbances of varying magnitude and duration depending on the type and proximity of fault.
Slide 10: Voltage Unbalance
Types of PQ Problems Voltage Unbalance Maximum deviation from the average of the three-phase voltages divided by the average of the three-phase voltages, usually expressed in percent t •Unbalanced distribution of single phase loads •Unstable system neutral •One-phase out power supply
Slide 11: Total Harmonic Distortion (THD)
Types of PQ Problems Total Harmonic Distortion (THD) THD is the measure of the effective value of the harmonic components of a distorted waveform, that is, the potential heating value of the harmonics relative to the fundamental
Slide 12: Voltage Sag
Types of PQ Problems Voltage Sag A decrease in RMS voltage between 10% to 90% of the nominal value for duration from half cycle to 1 minute 1 minute or less • Starting of electric motors • Switching “on” of large loads • Fault on either distribution, transmission or generation systems
Slide 13: Voltage Sag
Types of PQ Problems Voltage Sag • Nominal Voltage: 460V • Magnitude: 88.41% • Duration: 4 cycles • Cause: Fault on the adjacent feeder
Slide 14: Voltage Transient
Types of PQ Problems Voltage Transient A sudden, non-power frequency change of voltage or current • Lightning • Load switching • Capacitor switching
Slide 15: Proper Grounding Practices
Types of PQ Problems Proper Grounding Practices From IEEE Emerald Book (Recommended Practice for Powering and Grounding Sensitive Equipment), 2005
Slide 16: AVR vs UPS
Solutions to PQ Problems AVR vs UPS Can handle "fluctuations" Can handle (between plus 10% to "fluctuations" and minus 10% of power interruptions nominal voltage) < 2 AC Cycles On line Can handle voltage Cannot handle sags and power voltage sags interruptions
Slide 17: UPS (Universal Power Supply)
Solutions to PQ Problems UPS (Universal Power Supply)
Slide 18: Sag Correctors
Solutions to PQ Problems Sag Correctors • Provides energy during voltage sag events • Small to large applications
Slide 19: Transient Voltage Surge Suppressor (TVSS)
Solutions to PQ Problems Transient Voltage Surge Suppressor (TVSS) • Provides protection from transient voltage
Slide 20: Maintenance Activities
Solutions to PQ Problems Maintenance Activities DESCRIPTION OF ACTIVITY CORRECTION OF OVERHEATING LINE COMPONENTS MISSING/CUT/DETACHED POLE GROUNDING CONDUCTOR (Correction) TREE PRUNING FOREIGN OBJECTS / KITE STRING REMOVAL REPLACEMENT OF PIN / CONTAMINATED INSULATORS INSTALLATION OF BIRD SPIKE
Slide 21: Pole Attachments
Solutions to PQ Problems Pole Attachments Bird spikes
Slide 22: Pole Attachments
Solutions to PQ Problems Pole Attachments Snake cones
Slide 23: Pole Attachments
Solutions to PQ Problems Pole Attachments Snake cones
Slide 24: Overhead Lines
Solutions to PQ Problems Overhead Lines FROM TO
Slide 25: MERALCO SUBSTATION
Solutions to PQ Problems MERALCO SUBSTATION • 83 MVA capacity • Equipped with On-load Tap Changer (OLTC)
Slide 26: Problem Evaluation
Solutions to PQ Problems Problem Evaluation • Problem Category Identification • Power Measurements & Data Collection • Solution Range Identification • Solution Evaluation • Optimum Solution
Slide 27: Solution Evaluation
Solution to PQ Problems Solution Evaluation LEAST COST APPROACH Equipment Specification Control Protection Over-all Protection Utility 1 Inside Plant Solution Controls 2 3 4 Motors Other Loads INCREASING COST
Slide 28: Thank You!
Even without buying PQ conditioning equipment we may already be paying for it from costs associated with current problems that our equipment are dealing with. Thank You!
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