Protecting & Ice Melting Westman’s Distribution Lines

1. Protecting & Ice Melting Westman’s Distribution Lines Speaker Scott Whaley - EIT

2. Western Distribution Region • The western distribution’s head office is located in Brandon • There is currently five engineers helping maintain and develop the western distribution area • Distribution system consists of: • 4 kV (kilo volts) , 8kV, 12kV and 25kV power lines • Sub-transmission system consists of: • 33kV and 66kV power lines

3. Distribution Infrastructure • Hydro has approximately 150 stations in Western Manitoba • Standard metal and wood sub stations • New DSC stations • There are over 500 feeders in Western Manitoba to protect • Length of feeders vary to being very short in urban areas and can be quite long (20 miles) in rural locations

4. Distribution Infrastructure • Distribution protection starts at the high side fuse/breaker at the station transformer and includes all distribution power lines up to the customer service transformer Station Transformer Distribution Power Lines Customer Service

5. Protective Equipment • Reclosers (ACR) • Automatic circuit recloser • Use electronic & hydraulic • Sectionalizers • Detect current pulses to trip • Fuses • Expulsion fuses and current limiting fuses • Circuit Breakers • Mechanical circuit breakers

6. Protective Equipment • FAULTED CIRCUIT INDICATERS (FCI)are installed on distribution lines where standard protective device such as an ACR, fuse or sectionalizer can not be installed • FCIs are installed to eliminate the need to repeatedly test and energize U/G cables when there is a fault. This prevents permanent damage to the cable • Aid In troubleshooting

7. Equipment Coordination • Protective equipment must be properly set to allow for feeder coordination • Protective equipment provides safety and reliability to both the customer and employees and helps locate line faults • We install protective devices to prevent equipment damage

8. Protecting Distribution Lines Station Recloser Down line Recloser Regulator Fuses

9. Protecting Distribution Lines EXAMPLE

10. Protecting Distribution Lines EXAMPLE

11. Protecting Distribution Lines EXAMPLE • Fault current of 400 amps • 50 amps ACR – 2A+2B • Time for fast trip = 0.05 secs. • Time for slow trip = 0.32 secs. • Fault current of 400 amps • Station ACR – MT= 240 amps, 2N+2E • Time for fast trip = 0.22 secs. • Time for slow trip = 4.30 secs.

12. Protecting Distribution Lines • If we issue protection coordination setting correctly we can prevent damage to equipment • MB Hydro has implemented standards for installing, protecting and rating equipment. These standards prevent damage to our infrastructure and reduce customer outages

13. Standards Drawing of a 1Ø Transformer

14. Ice Melting • Ice melting is done by purposely placing a fault on a feeder. The line fault creates tremendous heat which melts the bonded ice. • Each ice melt done on a distribution line must be calculated differently because line impedance predetermines the fault current values • Length, conductor size, temperature and time must all be taken into account when melting

15. Ice Rolling • Manually using ice rollers to remove built up ice on the power lines. The process is slow and time consuming and takes at least ½ hour to do 1 mile.

16. Ice Prone Areas • Ice melting is • incorporated into • Hydro’s standards

17. Ice Detection System • The system is built using an infrared camera to capture images of the conductor. It calculates and notifies staff if there is ice build up on the line • The ice vision system uses an embedded computer with custom designed software to perform the ice monitoring calculations • A web based application displays information which includes: • Ice build up (thickness) on the conductor • Temperature • Wind Speed

18. Ice Detection Camera • Every second represents 30 minutes

19. Thank You Questions and Comments For career opportunities visit: http://www.hydro.mb.ca/careers