Switch yard & Protection

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all technical data info in one slide including testing & protection of switch yard

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Switch yard & Protection

  1. 1. 1 BLA Power Pvt. Ltd
  2. 2. 2
  3. 3. DEFINATION • A switchyard is a part of an electrical Generation, Transmission, and Distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. • Switchyards generally have Breakers, Isolators , CTs ,PTs , Bus bars, protection and control equipments, transformers ,grounding wires and switches, disconnects and metering devices, etc. 3
  4. 4. 132 KV Switchyard • Constructional Overview • Testing • Operation & Maintenance • Protection • Conclusion 4
  5. 5. Constructional Overview • Two main Bus-1& 2 bars – ACSR TWIN MOOSE Conductor. Both are used to energize any abnormality with Bus-coupler for un interruption Operation. • Current rating 2000A,Fault Level 40KA for 3 Sec. • Bay Equipment to Equipment Connection-ACSR Moose Conductor. • CTs are connected in Series , PTs are connected across supply. • STG Generator Transformer Bay -01 No. • Start-up S.A.T. Bay -01 No. • 132 KV overhead line circuit Bay -02 No.s • 132 KV Transfer Bus coupler Bay - 01 No.s • Fully Equipped Bus PT Bay -02 No.s 5
  6. 6. 6 GEN. TRFO. BAY TRNSFER BUS COUPLER BAY BUS PT O/G OHL #1 BAY STN. TRFO. BAY O/G OHL # 2 BAY
  7. 7. • Total no. of Towers- 28 (A/B/C/D/E) • Total no. of SF6 CB- 5 • Total no. of PT-12 • Total no. of CT-12 • Total no. of LA-12 • Total no. of Wave Trap -2 • Total no. of Isolators- 22 • Total no. of CVT- 6 • Total no. of BPI- 18 • Total no. of EMPT -6 7 Constructional Overview
  8. 8. 8 GEN BAY SAT BAY
  9. 9. 9 B/C BAY Line# 1 & 2 BAY
  10. 10. 10 Bus Bar Protection Scheme
  11. 11. • Rated Voltage 145 KV • Rated Current 1250 A Frequency 50 Hz • Breaking Capacity 40 KA • Making Capacity 100 KVP • Short Time Rating 40 KA for 3 sec • Operating sequence O-0.3 sec - CO- 3 MIN- CO • Trip and Closing Coil Voltage 110V DC • Motor Supply 240 V 11 These are used to operate on the fault on line or X-mer depending upon where it is connected. This isolates the faulty line or equipments from the live portion of the sub station by opening automatically through protective relays; control cables etc. in definite time. Testing for SF6:- Applied Volt 5KV DC •IR Value > 20 GΩ CB ON [R(Y+B+E),Y(R+B+E),B(R+Y+E)] > 50 GΩ CB OFF [R-R’,Y-Y’,B-B’] •Applied current 100 A DC Contact Resistance test: R-ø ,Y-ø B-ø < 34 μΩ •SF6 Gas pressure setting 5.4 bar. •Breaker , Closing Time 72 ms Opening Time -29 ms Each Phase
  12. 12. 12 Make CGL Type Outdoor No of Core 2 Core Ratio 400-800/1-1A Class 0.25/0.25 Burden 30 VA ISF <= 5 Make CGL No of Core 2 Ratio 132KV/√3/110V/√3/110V/√3 Class 0.2/3P Burden 100 VA/100 VA a) Measurement of voltage b) Provide secondary voltage for protection. a) Measurement of current b) Protection current circuits when currents passed through protective relays like Distance protection, Backup protection.
  13. 13. Common Testing's Required for CT & PT:- •IR Test : Applied Volt 5KV DC > 10 GΩ [Prim – Earth, Prim – Core] Applied Volt 1KV DC > 500 MΩ [Core-Earth] •Winding Resistance Test: < 5-6 Ω [Ex: R-ø ,1s1-1s2,1s1-1s3] •Ratio Test : [Prim current 400-800]/ [Sec. current 1-1A] [Ex: R-ø ,1s1-1s2,2s1-2s2] •Polarity Test : [Ex: R-ø ,1s1-1s2,2s1-2s2] •Knee voltage Test: [Only For Protection Class CT ] is significance of saturation level of a current transformer core mainly used for protection purposes. The sinusoidal voltage of rated frequency is applied to the secondary terminals of CT, with other winding being open circuited which increased by10%, cause the exiting current to increase by 50%. NEXT Press
  14. 14. 14 P1 P2 S1 S2 Battery 9V Press Back •Polarity Test :
  15. 15. Make OBLUM ELECTRICAL Type METAL OXIDE LD DISCHARGE CLASS Class-3 Rated Voltage 60 KV Rated Frequency 48-62 HZ Maximum continuous Operating Voltage 102 KV Nominal Discharge Current 10 KA MFD 2010 Make OBLUM ELECTRICAL  Wave trap is an instrument of Low pass filter, when power frequency currents are passed to switchyard & high freq. signals are blocked. Line trap also is known as Wave trap.  Shapes like a DRUM. Use for Carrier Communication (PLCC) systems for communication among various substations without dependence on the telecom company network located in substation control room (through coupling capacitor and LMU). To discharge the switching & lighting voltage surges to earth to protect instrument in the station. These are high pass filters (50 KHZ to 500 KHZ) pass carrier. 15
  16. 16. 16 Make CGL No of Core 3 Ratio 132KV/√3/110V/√3/110V/√3/110V Class 0.2/3P/3P Burden 100 VA/100 VA/100VA > CVT is a transformer used to step down extra high volt. Signals & provide low volt. Signals either for measurement or to operate protective relays. CVTs are typically 1-ø devices where stack of capacitors are connected in series result voltage drop. Make S & S POWER SWITCHGEAR EQUIPMENT LTD. Type Drive Motor/Manual,415 v,3ø Rated Voltage 145 kv Rated Current 1250 A Frequency 50 Hz Short Time Rating 100 KA for 3 sec Lightning Impulse with stand Across voltage 650 kv > Isolators are used to isolate the high Volt. from flow through the line into the Bus. It allows only needed voltage and rest is earthed by itself if required. Bushing
  17. 17. 17 •Bus: is a line in which the incoming feeder come into & get into the instruments for further step up or step down. •Double line in the bus so that if any fault occurs in one the other can still have the current and the supply will not stop. •Two lines are separated by a little distance by a conductor [spacer] having a connector between them . Spacer Clamp Tension Suspension
  18. 18. OPERATIONAL MODES • Normal Operation : Synchronization Start Up / Import • Inter -Transfer Mode Operation: Inter Transfer Mode By Pass change over Scheme: 18 Press Press Move Next Press Press
  19. 19. G 19 DS-1 DS-2 CB CB DS-4 DS-3 DS-2 CB DS-4 DS-3DS-1 DS-2 CB DS-3 DS-4 DS-1 DS-2 CB DS-4 DS-1 DS-3 OUTGOING OHL #2 BAYOUTGOING OHL #1 BAY BUS COUPLER CUM TRNSFER BREAKER MAIN -1 BUS MAIN -2 CUM TRANSFER BUS <--- GT BAY  <--- STN. TRFO BAY  GENERATOR G. TRFO STN. TRFO DS-5 DS-5 U.A.TRFO DS-1 DS-2 Gen CB LOAD
  20. 20. G 20 DS-1 DS-2 CB CB DS-4 DS-3 DS-2 CB DS-4 DS-3DS-1 DS-2 CB DS-3 DS-4 DS-1 DS-2 CB DS-4 DS-1 DS-3 OUTGOING OHL #2 BAYOUTGOING OHL #1 BAY BUS COUPLER CUM TRNSFER BREAKER MAIN -1 BUS MAIN -2 CUM TRANSFER BUS <--- GT BAY  <--- STN. TRFO BAY  GENERATOR G. TRFO STN. TRFO DS-5 DS-5 U.A.TRFO DS-1 DS-2 LOADLOAD Press Back
  21. 21. G 21 DS-1 DS-2 CB CB DS-4 DS-3 DS-2 CB DS-4 DS-3DS-1 DS-2 CB DS-3 DS-4 DS-1 DS-2 CB DS-4 DS-1 DS-3 OUTGOING OHL #2 BAYOUTGOING OHL #1 BAY BUS COUPLER CUM TRNSFER BREAKER MAIN -1 BUS MAIN -2 CUM TRANSFER BUS <--- GT BAY  <--- STN. TRFO BAY  GENERATOR G. TRFO STN. TRFO DS-5 DS-5 U.A.TRFO DS-1 DS-2 LOADLOAD Press Back
  22. 22. 22 CB DS-2 CB DS-4 DS-3DS-1 BUS COUPLER CUM TRNSFER BREAKERS MAIN -1 BUS MAIN -2 CUM TRANSFER BUS DS-1 DS-2 Tripping Prt. OUTGOING OHL #1 BAY 1. Close DS-3 2. Open DS-3 & DS4 Close DS-3 Tripping Prt.
  23. 23. 23 CB DS-2 CB DS-4 DS-3 DS-1 BUS COUPLER CUM TRNSFER BREAKER MAIN -1 BUS MAIN -2 CUM TRANSFER BUS DS-1 DS-2 Press Back Tripping Prt. OUTGOING OHL #1 BAY
  24. 24. 24 CB DS-2 CB DS-4 DS-3DS-1 BUS COUPLER CUM TRNSFER BREAKERS MAIN -1 BUS MAIN -2 CUM TRANSFER BUS DS-1 DS-2 Tripping Prt. OUTGOING OHL #1 BAY 1. Open DS-1 2. Close DS-1 Tripping Prt. Protection Tripping fuse Out Press Back
  25. 25. Maintenance • CTs, PTs ,all auxiliaries terminal tightness. • SF6 Breaker Gas pressure monitoring & maintain. • Stone,metnal layer maintain across the area. • Monitoring & diagnosis using Hotspot detector or temperature scanner . • Isolator & contact cleaning on scheduled. 25
  26. 26. Thermal Sensor / Hot Spot Detector 26
  27. 27. 27
  28. 28. Protection 28
  29. 29. 29
  30. 30. 30
  31. 31. Protection System • A series of devices whose main purpose is to protect persons and primary electric power equipment from the effects of faults.
  32. 32. Why A System Needs Protection? • There is no ‘fault free’ system. • It is neither practical nor economical to build a ‘fault free’ system. • Electrical system shall tolerate certain degree of faults. • Usually faults are caused by breakdown of insulation due to various reasons: Short Circuit, High Voltage, system aging, lighting, etc.
  33. 33. Protection System Elements • Protective relays • Circuit breakers • Current and voltage transducers • Communications channels • DC supply system • Control cables
  34. 34. Three-Phase Diagram of the Protection scheme CTs VTs Relay CB Control Protected Equipment
  35. 35. How Do Relays Detect Faults? • When a fault takes place, the current, voltage, frequency, and other electrical variables behave in a peculiar way. For example: – Current suddenly increases – Voltage suddenly decreases • Relays can measure the currents and the voltages and detect that there is an overcurrent, or an undervoltage, or a combination of both • Many other detection principles determine the design of protective relays
  36. 36. Main Protection Requirements • Reliability • Selectivity • Speed • Sensitivity
  37. 37. Typical Short-Circuit Type Distribution Single-Phase-Ground: 70–80% Phase-Phase-Ground: 17–10% Phase-Phase: 10–08% Three-Phase: 03–02%
  38. 38. Following type of Protection Curve used in our plant 1. INSTANTANEOUS/High Speed 2. DMT: (Definite Mean Time-I>>/high set) 3. IDMT: (Inverse Definite Minimum Time) a. SI - Standard Inverse (I>) b. VI - Very Inverse c. EI - Extreme Inverse d. LTI - Long Time Inverse
  39. 39. Formula for Relay Operating Time calculation Operating Time: = A X TMS Ir C - 1 o A=0.14 & C=0.02 for SI o A=0.13.5 & C=1.0 for VI o A= 80 & C= 2.0 for EI o A=120 & C=1.0 for LTI o Ir= I(multiple of fault current) / Iset
  40. 40. Example: • If FLC=100A, % setting =105, • Operate time = 10sec Then TMS=? If CTR =150/1A, In=150, Isec=1A As per CTR % set= 0.7*In. Relay Iset= 700mA, Ir=1.05/1.0=1.05 =>TMS will be 0.136
  41. 41. IDMT:SI
  42. 42. IDMT:
  43. 43. Basic Requirement for Relay Setting • Equipment Full Rating(V, Amp, Z) • CT/PT Ratio installed on that feeder • Identification of CT/PT for Particular protection. • Breaker opening & tripping time. • Equipments Factory Test report/Curve
  44. 44. Relay Setting Adopted for our system: 1. OC: 105% to 120% - SI, 2. EF: 10% to 30%. - SI 3. OV: 110%, U/V: 80% - DMT 4. SEF: more than EF and time >0.8to1.0sc. 5. REF/Diff : 08 to12% -Inst. 6. DPR (Z1-inst. Z2-300ms, Z-800ms)
  45. 45. Protection used for different System • For Transmission Line : a. Distance Protection b. Backup Direction OC/EF c. Lightning Protection • For Transformer: a. Differential Protection b. Overfluxing c. O/C & E/F d. Restricted E/F
  46. 46. e.Sensitive or standby E/F f. Buchholz g. Pressure Release Valve h. Winding/ oil Temperature & LA • For LT Motor (up to 35KW) a. Thermal Overload b. Fuse • For LT Motor (Above 35KW) a. Thermal Over Laod b. O/C & E/F
  47. 47. • For HT Motors: a. Thermal Over Load b. O/C & E/F c. Locked Rotor d. Negative Phase Sequence e. Start supervision f. Restart Inhabit • For Generator : a. Differential Protection b. Stator Earth Fault (100% & 90 %)
  48. 48. c. Rotor E/F d. NPS e. Backup Impedance f. Backup O/C & E/F g. Loss of field h. Reverse Power (Short Time /Long time) i. Thermal Overload Alarm j. Dead Machine k. Winding temperature l. O/V & U/V
  49. 49. .
  50. 50. SUMMARY • The Operative Direction for Directional OC Relays are as follows: – GT bay relay is having operative direction towards GT. – Line bay relay is having operative direction towards Line. – Station Transformer. Relay is having operative direction towards Station Transformer. • Grading margin of 0.3 seconds has been considered between different levels of protective devices. • In case of a fault on Line, Distance relay will operate instantaneously. If it fails to Operate than Directional OC relay will operate as backup. • If the fault is still found persisting than GT bay and other line bay relay will give further backup and will trip their respective breakers to clear the fault. • In case of a fault on Bus, Bus differential relay will operate instantaneously. If this relay fails to clear the fault , all other feeders including two line bays and GT bay relays will trip their respective breakers to clear the fault . • In case of a fault in Generator Transformer (GT),Differential protection for GT will operate instantaneously. And Directional relay looking towards GT will give backup to it. If the fault is still found persisting than all other feeders including two line bays will trip their respective breaker to clear the fault.
  51. 51. Forward Path • For Trouble Free Operation. • Longevity of System. • 2 No.s Upcoming Bays for Unit-II 51
  52. 52. Special Thanks • for Guidance Mr. U.P. Sharma Sr. Manager [ Dept. Of Electrical ] • for Co-ordination Mr. Nilesh Malviya Mr. Dhanajya Ray Engineer [ Dept. Of Electrical ] 52

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