Presentation Transcript

1. RESEARCH SEMINAR ON POWER QUALITY ISSUES

   Dr.V.V.Karthikeyan
2. Presentation Overview Introduction Power Quality Issues Possible Solutions for Power Quality Problems
3. Introduction A perfect power supply, that is available within voltage and frequency tolerances, has a sinusoidal wave shape. With proliferation of non-linear loads such as diode/thyristorrectifiers, non-sinusoidal currents degrade the power quality in power transmission/distribution systems. The power quality, that is actually the voltage quality, is being addressed in most cases.
4. Introduction continued.. Interest in Power Quality has increased significantly over the last decade. The main reason for the awareness of the power quality problems is the load equipment which is more sensitive to power quality variations. Modern load devices contain microprocessor based controls and power electronic devices that are sensitive to power disturbances. The term “poor power quality” means that there is a sufficient deviation from standards that can cause equipment failure. Such deviations are due to non- linear loads in the system.
5. Power Quality Issues Sources of Harmonics Static Power Converters Arc furnaces, mine hoists loads Switched Mode Power Supplies (SMPS) PWM Drive Utility Interface with Distributed Energy Sources Problems due to Harmonics Problems on the customer side Problems on the utility side Consequences of harmonic distortion on equipments Power quality standards Possible solutions to power quality problems
6. Contents Effects of power quality Power Quality definitions revisited What is needed for PQ monitoring ? GE Multilin’s solution PQMII EPM9000 series Summary Monitor and Analyze Power Disturbances, Disruptions & Harmonics
7. PQ is a Business Problem Power Quality issues cause business problems such as: Lost productivity, idle people and equipment Lost orders, good will, customers and profits Lost transactions and orders not being processed Revenue and accounting problems Customer and/or management dissatisfaction Overtime required to make up for lost work time According to Electric Light and Power Magazine, 30 to 40 Percent of All Business Downtime Is Related to Power Quality Problems.
8. Is Power Quality Such a Big Problem?
9. Why PQ is such a Big Problem? The sensitivity of today’s electronic equipment makes it susceptible to power disturbances For some devices, a momentary disturbance can cause scrambled data interrupted communications a frozen mouse system crashes and equipment failure
10. PQ Problems are Expensive Berkeley Lab Study Estimates $80 Billion Annual Cost of Power Interruptions … Research News, Berkeley Lab, February 2, 2005 $50 billon per year in the USA is lost as a results of power quality breakdowns …. Bank of America Report A manufacturing company lost more than $3 million one day last summer in Silicon Valley when the “lights went out.” … New York Times January 2000 “A voltage sag in a paper mill can waste a whole day of production - $250,000 loss” … Business Week, June 17,, 1996 Half of all computer problems and one-third of all data loss can be traced back to the power line … Contingency Planning Research, LAN Times
11. Who is Affected? High Cost Facilities Semiconductor plants Pharmaceuticals Data centers Lost production Scrap Costs to restart Labor costs Equipment damage and repair Other costs MediumCost Facilities Automotive manufacturing Glass plants Plastics & Chemicals Textiles
12. PQ Definitions Revisited
13. PQ Definitions Revisited
14. PQ Definitions Revisited
15. PQ Definitions Revisited
16. PQ Definitions Revisited
17. PQ Definitions Revisited For Electric Utilities Control of Voltage and Prevention of Outages is Power Quality
18. Sources of PQ Problems Internal Sources Individual Loads –Lighting, Elevators, Coolers, HVAC Uninterruptible Power Supplies Variable Frequency Drives Battery Chargers Large Motors During Startup Electronic Dimming Systems Lighting Ballasts (esp. Electronic) Arc Welders, and Other Arc Devices Medical Equipment, e.g. MRIs and X-Ray Machines Office Equipment and Computers Wiring Utility Sources Lightning PF Correction Equipment Faults Switching
19. PQ Problems and Possible Causes
20. PQ Problems and Possible Causes
21. PQ Problems and Possible Causes
22. PQ Problems and Possible Causes
23. PQ Problems and Possible Causes
24. Outages, 6% Spikes, 7% Swells, Sags, 56% 31% Source: EPRI, 1994 Major PQ Problems Swells System fault conditions Switching on a large capacitor bank Switching off a large load Sags (Dips) Associated with system faults Switching of heavy loads Starting of large motors
25. Textile Industry Plastics Industry Glass Industry Process Industry Semiconductors $1k $10k $100k $1M $10M Source: EPRI “The Economics of Custom Power”, IEEE T&D Show 2003 Losses per Voltage Sag Event Cost of Voltage Sags
26. Momentary Outages create problems when computers and clocks reset, equipment stalls, and work stops. Cost of Momentary Outages
27. It provides data to see, diagnose and avert looming problems – “like squeaky brakes on a car” Trends can be detected JIT equipment maintenance programs can be established It acts like a “Black Box” on an airplane to tell you what, when, and where a Power Quality event occurred … to prevent it from reoccurring Benefits of Continuous PQ Monitoring Power Quality monitoring provides a continuous “Health Check” of a facility’s power system … for example: Harmonic interaction between loads and power conditioning equipment spotted High Inrush currents from equipment startup detected Transients from load switching are seen ContinuousPQ Monitoring Detects, Records, and Leads to the Prevention of PQ Problems
28. What is needed for PQ Monitoring? Plus they must … Be easy to use Be Suitable for continuously monitoring indoors and outdoors Interface with standard PQ analysis Software…PQDif format Be fast enough to capture high speed events that produce equipment problems Have enough storage to save the waveforms you need Have PQ analysis tools that produce usable, actionable recommendations PQ Monitors must detect and record the 7 types of PQ problems Transients Interruptions Sag/Under Voltage Swell/Over Voltage Waveform Distortion Voltage Fluctuations Frequency Variations These include Flicker and Compliance to ITI(CBEMA), IEEE and ISO Standards ITI: Information Technology Industry Council (Computer & Business Equipment Manufacturer’s Association)
29. Real Time Field Recorded Events Source: AGA Brazil Meter: EPM9650 Period: Jan 2005 – Dec 2005 Continuous Monitoring of the Station for PQ Problems
30. Finally… If You Can’t Measure it You Can’t Manage it If You Can Measure it You Can Manage it Thank you ….