Harmonic mitigating transformer
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This document discusses harmonic mitigating transformers (HMTs) and their use in reducing harmonic distortion in electrical systems. It begins with an introduction describing how increased use of electronic equipment has led to higher levels of harmonic distortion, which can negatively impact system reliability. It then provides details on common harmonic sources, the symptoms caused by harmonics, and how HMTs work to phase-shift and cancel harmonic currents. The document explains the construction, benefits, and appropriate markets for HMTs, concluding that they provide an effective and cost-efficient means of reducing harmonics and improving system reliability.
Harmonic mitigating transformer
- 1. ON BY: Mr. Sidharth Goutam Dash Electrical Engineering Regd. No.: 0901106181 Submitted To: Prof. Dr. A. Mohapatra Prof. Dr. R.K. Jena
- 2. INTRODUCTION As our world becomes even more dependent on electrical and electronic equipment, there is an increased likelihood that operations will experience the negative effects of harmonic distortion. The productivity and efficiency gains achieved from increasingly sophisticated pieces of equipment have a drawback: increased harmonic distortion in the electrical distribution system. Harmonic mitigating transformers (HMTs) are a leading solution to eliminate these harmful harmonics and improve your system reliability.
- 5. Sources of Harmonics General sources of harmonics • Power electronic equipment (drives, rectifiers, computers, etc.) • Arcing devices (welders, arc furnaces, florescent lights, etc.) • Iron saturating devices (transformers) • Rotating machines (generators) Most prevalent and growing harmonic sources: • Adjustable frequency drives (AFD) • Switch-mode power supplies (computers) • Fluorescent lightning
- 6. Symptoms of harmonics •Over-loaded neutral conductors •Over heated motors and transformers •Blown fuses or breakers tripping repeatedly •Failure of power factor correction capacitors Timing errors in sensitive electronic equipment
- 8. What do HMTs do? HMTs are an economical solution in the battle against the harmful effects of harmonics. HMTs are highly reliable devices; they don’t have any moving parts and they are typically energized 24/7, 365 days a year. This means that they are always “on the job” treating harmonics, regardless of the level of load they are serving at a given point in time. Whenever the HMT is energized, it will provide harmonic treatment.
- 10. A typical HMT
- 11. Principle of HMT Harmonic mitigating transformers use phase-shifting , electromagnetic flux cancellation, and source impedance to reduce harmonic currents in electrical distribution systems. By reducing the amount of heat that harmonics generate, these devices enable transformers to operate at lower temperatures. The result is lower cooling costs as well as longer device life and reduced maintenance. Harmonic mitigating transformers also enable the use of a transformer’s full capacity and ensure compliance with harmonic limits defined by the Institute of Electric and Electronic Engineers and other organizations.
- 13. Parts of a HMT Usually a HMT consists of five parts Core & Coil Assemblies Taps Electrostatic Sheilding Wiring/ Terminations Enclosures
- 15. Infrared heat scans of transformers when feeding the same non-linear, computer load.
- 16. Benefits: •Reduces the K-Factor Ratio of the loads. •Saves energy. •Prevents distribution system apparatus from overheating. •Saves money. •Balances phase currents and voltages on primary. •Reduces voltage distortion. •Increases system capacity and reliability. •Reduces apparatus vibration and noise. •Prevents electronic circuit breaker malfunctions. •Provides a healthier environment for the loads.
- 17. . MARKETS FOR HMT: 1 .EDUCATIONAL FACILITIESSchools and colleges have laboratories that contain an ever-increasing number of electronic devices which give rise to Harmonics. In educational institutes HMTs can be installed. 2. COMMERCIAL FACILITIESIn commercial office-buildings, customer service call-centers, insurance companies, government offices, presence of computers, printers and copying machines create an environment that is full of Harmonics. Installing HMTs can prevent losses. 3 .RETAIL FACILITIESElectronics and appliance stores as well as plaza and malls and grocery stores typically make use of electronic devices. HMTs can be used in these places to avoid harmonics.
- 18. 4 .MEDICAL FACILITIESThese are the ideal locations for HMTs. Most modern diagnostic and analysis equipments are electronic. Excessive harmonics may cause personal records or medical test data to be corrupted or destroyed. 5.GAMNG INDUSTRYHMTs can be beneficial in casinos, racetracks and offtrack-gaming parlors.
- 19. HMTs are a cost effective means of treating harmful harmonics . Reducing harmonic content in electrical systems can result in a more reliable electrical system , lower maintenance cost ,less equipment malfunction and lower cooling capacity. In short , taking HARM out of HARMONICS was never this easy .