620693379-Distribution-Line-Protection-1.pptx

Distribution line protection

1. Distribution Line Protection and Maintenance Presented By MD GOLAM MOWLA Executive Engineer( Grid, System Protection and Energy Audit)

2. Session-1 Mechanical Protection Push Pole Guy wire H-Pole B . Electrical Protection DOFC FUSE MCB ACR/OCR LA CAPACITORBANK Automatic Voltage Regulator

3. Session-2 Over Current and earth fault Protection connection diagram of O/C & E/F Relay ( 3PO/C+EF) , ( 2P O/C+EF) Under and over voltage protection Directional protection protection of radial Feeder Parallel feeder Ring main system Time graded Over current and earth fault protection Characteristic curve plug setting multiplier time setting multiplier Relay co-ordination 'distribution

4. Session-3 Transformer Grounding Pole Grounding Equipment Grounding Types of Faults Remedy of Fault Fault current Calculation Fault Clearing time and safety Margin

5. Session-4 A. Maintenance Procedure Schedule Maintenance Preventive Maintenance . Breakdown or Emergency Maintenance B . Right of way

6. Session-5 Necessary Testing and Maintenance tools for Line Maintenance Megger (High Insulation Tester ) Earth Tester Clip on Meter Multi meter Chain Block 2 ton Ratchet I ton Conductor cutter Hot Stick Wrench set Insulated pliers Allen key set Tree Trimming Saw Safety belt, Helmet o Safety Gloves etc.

7. Mechanical Protection of Distribution line Push Pole

8. Mechanical Protection of Distribution line Guy Wire

9. Mechanical Protection of Distribution line H-Pole

10. Mechanical Protection of Distribution line H-Pole

11. B. Electrical Protection of Distribution line ACR/OCR In  electric power distribution ,  automatic circuit reclosers  ( ACRs ) are a class of  switchgear  which is designed for use on overhead electricity distribution networks to detect and interrupt momentary  faults . Also known as  reclosers  or  autoreclosers , ACRs are essentially  high voltage  rated  circuit breakers  with integrated current and voltage sensors and a  protection relay , optimized for use as an overhead network distribution protection asset. Commercial ACRs are governed by the ANSI/IEEE C37.60, IEC 62271-111 and IEC 62271-200 standards. The three major classes of operating voltage are 15.5 kV, 27 kV and 38 kV.

12. B. Electrical Protection of Distribution line ACR/OCR

13. B. Electrical Protection of Distribution line ACR/OCR

14. B. Electrical Protection of Distribution line ACR/OCR Recloser interrupting mediums Oil interrupters Reclosers using oil for current interruption use the same oil for basic insulation. Some reclosers with hydraulic control also utilize the same oil for timing and counting functions Vacuum interrupters Vacuum interrupters provide fast, low-energy arc interruption with long contact and interrupter life, low mechanical stress, and maximum operating safety. With arc interruption taking place in a vacuum, contact and interrupter life far exceeds other interrupting media. Depending on type, a vacuum recloser may use oil, air, or epoxy as the insulating medium.

15. Single-phase reclosers  are used to protect single-phase lines such as branches or taps of a three-phase feeder. They can also be used on three-phase circuits where the load is predominantly single-phase. When a permanent phase-to-ground fault occurs, one phase can be locked-out while service is maintained to the remaining two-thirds of the system.  Due to the lighter weight of the single-phase recloser compared to larger three-phase reclosers , single-phase reclosers are typically mounted directly to the pole or substation steel structure individually by the built-in mounting hanger bracket which eliminates the need for an additional mounting frame. Single-phase reclosers can be controlled with a hydraulic control (integrated within the recloser tank), or an electronic control (housed in a separate enclosure) based upon the recloser design.

16. Automatic Voltage Regulator

17. Under Voltage Protection(27) Over Voltage Protection(59) What causes over voltages? Power system surges. Due to poor regulation of the power source or power utility company, voltage fluctuations either over or under may occur. ... Insulation Failure. ... Arcing Ground. ... Resonance. ... External causes . Over voltage protection  is a power supply feature which shuts down the supply, or clamps the output, when the voltage exceeds a preset level. Most power supplies use an  over-voltage protection  circuit to prevent damage to the electronic components.

18. What is Over Voltage Protection(59) Over voltage protection  is a power supply feature which shuts down the supply, or clamps the output, when the voltage exceeds a preset level. Most power supplies use an  over-voltage protection  circuit to prevent damage to the electronic components. What Is  Under voltage ?   Under voltage  conditions are usually be caused by undersized or overloaded utility and facility transformers. During peak demand periods and/or when the utility is experiencing problems, the demand for power exceeds the capability of the transformer and as a result the  voltage  drops .

19. Under Voltage Protection(27) Over Voltage Protection(59) Under voltage protection  is commonly used to.  protect  motors from damage during abnormal conditions and to prevent breaker-fed motors from re-accelerating after a restoration of bus  voltage Example :-Under Voltage Protection settings Characteristics-Definite time Operation Mode-1/3,2/3,3/3 U1<90% of 11 KVolt T1-5 sec-Alarm U1<85% of 11KV T2=1 sec

20. Example-Over Voltage Protection(59) Parameter settings of over voltage Characteristics-Definite time Operation Mode-1/3,2/3,3/3 U1>110% of 11 KVolt T1-5 sec-Alarm U1<120 % of 11KV T2=1 sec

21. Over current and earth fault protection 10/28/2019 56 50/51 I R IY IB IN 50N/51N 50/5 1 IR IY IB IN 50 N /51N

22. Protection Metering Differential Protection Main Bus Protection Reserve Bus Protection 1S1 1S3 1S2 2S2 2 S1 3 S1 2 S3 3S3 3S2 4S2 4 S1 5 S1 4S3 5S3 5 S2

23. ANSI TYPE OF PROTECTION APPLICATION VOLTAGE LEVEL 51P OVER CURRENT Line and Transformer(1p,2p,3P),IDMT ALL 51N Earth fault Line and Transformer(1P-E,,PP-E,3P-E)IDMT 50/50N High speed OC/EF Line and Transformer(all O/C and E/F)-DMT 67P/67N Directional OC/EF Line and Transformer(all O/C and E/F 87T Trans.DIFF Transformer(HV-LV,ALL,2 ND Harmonic,5 th harmonic,cross - blocking,over -excitation)DMT 87L Line DIff UG CABLE, Short Dist,Line charging current, 87N REF Star side of TR 87B Bus Differential 25 Synch Check Parallel line & TR 27 Under Voltage Line 59 Over Voltage Line and Transformer 49 Thermal Over Load Line

24. 21 Distance( Zone of protection-z1 to z4,load encroachment, phase selection, Power swing blocking,PUT,POT,DTT,EFCOM,ZCOM,1P-ARC,3P-ARC,67,67N) 79