BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

4. Generator and Ancillary Equipment4.1 Generator4.1.1 General RequirementsThe generator shall be designed and manufactured in accordance withInternational Electro-technical Commission Publication IEC 34.The generator shall be cooled by air, which in turn shall be cooled by water andair to water heat exchanger having independent closed circuit cooling watersystem [TEWAC type only].The MVAR leading capability shall not be less than 30 % of the MVA rating of thegenerator at 0.8 leading power factor. The generator in conjunction with itsexciters shall be designed to operate stably at all loads up to the maximumcontinuous rating.The generator shall be capable of operating continuously under unbalance loadingconditions when the negative phase sequence current component is less than 8%of the rated current.The generator shall be so designed as to minimise the effect of torsional rotoroscillation due to system disturbances and rapid load change. The generator shallwithstand continuous over-speed of 1.2 times of the rated speed without damage.The generator shall withstand 120% of rated current for more than 15 seconds.4.1.2 Generator Ratinga. Capacity at Site : To match gas turbine peak output at anyambient temperature.b. Power factor : 0.80 (lagging) to 0.95 lead.c. Frequency : 50 Hzd. Rated rotating speed : 3000 rpme. Rated voltage : 11 kV4.1.3 Voltage and Short Circuit RatioThe generator shall be capable of supplying the rated output at rated speed andat rated power factor with a voltage variation between 90% and 110% of therated voltage.The generator shall be designed to guarantee that a nominal short circuit ratio isnot less then 0.55 according to IEC 34.1.The generator shall withstand the electro magnetic and thermal stresses causingfrom short circuit fault at generator terminal without damage.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)33