Testing of the Limiters in offline (i.e.When the Machine is at stand still). 1. Field Current Maximum Limiter : a. Preliminary in order to ensure that the value displayed in the microterminal for Ifac is correct, measure the milli-volt drop across the FB Shunt & compute the same for rated value in terms of percentage. This computed value should match the value displayed in micro-terminal for Ifac. In case the values are different then calibration for Ifac has to be done. b. Please note down the Following parameters c. With Generator Terminal voltage at rated value (Uref= 100 %), Note down all the parameters of DVR as per table. d. Gradually increase terminal voltage by varying the reference value from local panel to a higher value i.e. in Micro-terminal Uref= 105%. e. With Generator Terminal voltage at 105% of rated value ( Uref= 105 %) , Note down all the parameters of DVR as per following table. f. Bring back the terminal voltage to rated value i.e. Uref=100%. g. Note down Field current variation from the above reading at 100 & 105 %. In order to check the intervention/operation of limiter, field current value shall be adjusted within the above two values recorded. h. After adjusting limiter value (F400) to new value, give step input to Generator voltage from 100 % to 105 %. i. Check operation / intervention of Field current maximum limiter. j. With the help of dual channel recorder record the limiter intervention. Also check the operation of output relay at digital output Module. k. With limiter in operated condition, note down all the parameters as per table. l. Restore the limiter values to original as per factory test report or as per site requirement. Parameter U reference Uref Generator Voltage Ugen Field Current Ifac Generator Current Igac Power P Control Voltage Uc Before operation of Limiter After operation of Limiter Remarks . 1 e. note down all the parameters as per table.Reactive Power Q Parameters to be recorded from micro terminal.e. d. Note down all the parameters of DVR as per following table. Module: 50% 2. f. In order to check the intervention/operation of limiter. With Generator Terminal voltage at rated value ( Uref= 100 %) . Note down Generator stator current variation zone hence obtained from reading at 100 & 105 %. Note down all the parameters of DVR as per table. Uref=100%. i. j. g. Inductive stator current value shall be adjusted within the above two values recorded. Ref. Also check the operation of output relay at digital output Module. With limiter in operated condition. Gradually increase terminal voltage by varying the reference value from Micro-terminal. I. Bring back the terminal voltage to rated value i. Check operation / intervention of Inductive stator current limiter. Value Uref= 105%.e adjust ref. With Generator Terminal voltage at 105% of rated value (Uref= 105 %). With the help of dual channel recorder record the intervention. m. Restore the limiter values to original as per factory test report or as per site requirement. Parameter U reference Uref Generator Voltage Ugen Field Current Ifac Before operation of Limiter After operation of Limiter Remarks . Check and ensure that the value in micro-terminal for Igac and the generator current meter reading in the control desk display the same value. b. h. Generator Current Igac Control Voltage Uc Power P Reactive Power Q Power Factor Cos 2 . c. Inductive Stator Current Limiter: a. After adjusting limiter value (F430) to new value. give step input to Generator voltage from 100 % to 105 %. Also check the operation of output relay at digital output card. d. capacitive stator current value shall be adjusted within this zone. i. Note down all the parameters of DVR as per table. \ Parameter Before operation of Limiter After operation of Limiter Remarks U Reference Uref Generator Voltage Ugen Field Current Ifac Generator Current Igac Control Voltage Uc Power P Reactive Power Q Power Factor Cos F 460 Ind 3 . At limiter operated condition. With Generator Terminal voltage at rated value ( Uref= 100 %) . note down all the parameters as per table. f. Bring back the terminal voltage to rated value i. Note down Generator stator current variation zone hence obtained from reading at 100 & 90 %. Gradually reduce terminal voltage by varying the reference value from Micro-terminal. Uref=100%. j. g. After adjusting limiter value (F460) to new value. I. With Generator Terminal voltage at 105% of rated value ( Uref= 90 %) .( Voltages shall be varied as per system conditions) c.e. Note down all the parameters of DVR as per following table. Restore the limiter values to original as per factory test report. h.6. Value Uref= 90%. give step input to Generator voltage from 100 % to 90 %. e. Capacitive Stator Current Limiter a.e adjust ref. Hence to check the intervention/operation of limiter. b. With the help of dual channel recorder record the intervention. Check operation / intervention of Capacitive stator current limiter. MVAR lead) = Xe = (change in vol.( Dact) = deg. Ug/ Ugn) / (change in MVAR/ S) Where.( all measurements are taken from microterminal ) power factor= Lead." Xe= (change in vol. Xq (C4A4) = (164. refer to the DVR factory test report document.U. S= Rated MVA capacity of generator. Load Angle Limiter a. Please refer calculations details for " External Network Reactance Xe P. For this. a. Reactive power Q = %( MVAR lead ) Delta act.19%) = Pu Xe (C4A6) = Pu = pu Procedure for Calculations of Xe & Xd 1.( Dact) = deg. Ug = Generator terminal Voltage Ugn= rated generator terminal voltage. Ug/ Ugn) / (change in MVAR/ S) = = = 2 Xd and Xe Values.00 V AC ( PT volts) Reactive power Q = Delta act. Take machine to inductive zone and note down readings as. Calculations Change in Ug/ Ugn = (U lag .7. This sheet gives details about machine synchronous reactance (direct axis 4 .U lead)/ Ugn = Change in MVAR = (MVAR lag . Take machine to capacitive zone and note down readings as. For reference. the data of BPCL DVR is enclosed. Ug= 110.( all measurements are taken from microterminal) Power factor= Lag. Ug= V AC. The value of Xq & Xe has to be entered in DVR. page titled " synchronous machine data & specification of excitation equipment". Note down Generator stator current variation zone hence obtained from reading at 100 & 90 %. Uref=100%.u. h.g.e. With Generator Terminal voltage at rated value ( Uref= 100 %) . After adjusting limiter value (F4A0) to new value. Note down all the parameters of DVR as per following table. capacitive stator current value shall be adjusted within this zone. note down all the parameters as per table.unsaturated / quadrature axis).e adjust ref. b. With the help of dual channel recorder record the intervention. j. I. Hence to check the intervention/operation of limiter. f. With Generator Terminal voltage at 105% of rated value ( Uref= 90 %) . e. Parameter U reference Uref Generator Voltage Ugen Field Current Ifac Before operation of Limiter After operation of Limiter Remarks is enclosed Generator Current Igac Control Voltage Uc Power P Reactive Power Q Power Factor Cos 5 . k. Also check the operation of output relay at digital output card. c. Note down all the parameters of DVR as per table. i. In case the Quadrature axis reactance is not mentioned then the value as given for direct axis unsaturated in the generator data sheet or DVR test report for e.( Voltages shall be varied as per system conditions) d. Gradually reduce terminal voltage by varying the reference value from Microterminal. reduce terminal voltage gradually from 100 % to 90 %.26% (1. Check operation / intervention of load angle limiter at set value.) then this value of Xd can be assumed. Value Uref= 90%. 192. Bring back the terminal voltage to rated value i. Restore the limiter values to original as per factory test report. g. At limiter operated condition.92 p.
Report "Davr Final Report-kahalgaon Unit 5 500 Mw"