Thyristor switched capacitor PPT
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The document discusses various methods and technologies for reactive power compensation in electrical systems, including thyristor-based devices such as Thyristor Switched Capacitors (TSC) and Thyristor Controlled Reactors (TCR). It highlights the benefits of these systems in improving voltage regulation, enhancing system stability, and reducing losses. Additionally, it references multiple academic sources and publications related to power distribution and control.
Thyristor switched capacitor PPT
- 2. kW: what we can use.. kVAr: loss.. kVA: the total capacity available
- 3. 1. The voltage regulation. 2. Increased system stability. 3. Better utilization of machines connected to the system. 4. Reducing losses associated with the system; and 5. To prevent voltage collapse as well as voltage sag.
- 4. 1. Thyristors switched capacitors (TSCs) 2. Thyristor controlled reactor (TCRs) 3. Combined TSC and TCR 4. Thyristor controlled series capacitor (TCSC) 1 3 2
- 5. 1. Capacitor bank 2. TSC reactor 3. Thyristor valve
- 6. 1 2
- 7. When the TSC is turned on….
- 9. a. TSC generates no harmonics. b. No filtering is required. c. SVCs have been built with only TSCs . d. relatively cost-effective. a) reactive power output can only be varied in steps. b) For continuously variable reactive power output, a TCR is required.
- 10. TCS can balance the voltage and current to normal levels, as we know that there is reactive power due to capacitive and inductive elements in the grid which can make the current and voltage phase difference, due to which the real power in the system reduces from the ideal level, but after we introduce the compensation device, the current and voltage waveforms have same phase, and due to this compensation effect, power in the system achieves to the desired value with stable voltage.
- 11. 1. Transmission system reactive power compensation , B. F. Wollenberg Minnesota Univ., Duluth, MN, USA, Date of Conference: 2002 Page(s): 507 - 508 vol.1 Print ISBN:0-7803-7322-7, INSPEC Accession Number: 7386352, DOI:10.1109/PESW.2002.985054 , Publisher: IEEE 2. T.J.E Miller, Reactive Power Control In Electrical Systems, John Willey & Sons, 1982 3. De Kock, Jan; Strauss, Cobus (2004). Practical Power Distribution for Industry. Elsevier. pp. 74–75. ISBN 9780750663960. 4. Deb, Anjan K. Power Line Ampacity System. CRC Press. pp. 169–171. ISBN 9780849313066. 5. Song, Y.H., Johns, A.T. Flexible ac transmission systems. IEE. ISBN 0852967713 6. Hingorani, N.G. & Gyugyi, L. Understanding FACTS Concepts and Technology of Flexible AC Transmission Systems. IEEE. ISBN 0780334558. 7. Ryan, H.M. (2001). High Voltage Engineering and Testing. IEE. pp. 160–161. ISBN 9780852967751. 8. Arrillaga,, J.; Watson, N. R. Power System Harmonics. Wiley. p. 126. ISBN 9780470851296.
Editor's Notes
- #8: When the TSC is turned on ("deblocked") again, care must be taken to choose the correct instant in order to avoid creating very large oscillatory currents. Since the TSC is a resonant circuit, any sudden shock excitation will produce a high frequency ringing effect which could damage the thyristor valve. The optimum time to turn on a TSC is when the capacitor is still charged to its normal peak value and the turnon command is sent at the minimum of valve voltage. If the TSC is deblocked at this point, the transition back into the conducting state will be smooth.
- #9: When the TSC is switched off, or ‘’blocked’’, no current flows and the voltage is supported by the thyristor valve. After the TSC has been switched off for a long time (hours) the capacitor will be fully discharged, and the thyristor valve will experience only the AC voltage of the SVC busbar. However, when the TSC turns off, it does so at zero current, corresponding to peak capacitor voltage. The capacitor only discharges very slowly, so the voltage experienced by the thyristor valve will reach a peak of more than twice the peak AC voltage, about half a cycle after blocking. The thyristor valve needs to contain enough thyristors in series to withstand this voltage safely.
- #10: disadvantage is that the reactive power output can only be varied in steps. Continuously variable reactive power output is only possible where the SVC contains a TCR or another variable element such as a STATCOM