Power Supply and Distribution in Mines

1
Power Supply and Distribution in Mines

• By Rob Polito 9805068J

2
Topics

• Introduction.
• Power Supply
• Design
• Power Distribution Equipment.
• Metal-clad Switchgear.
• Distribution.
• Basic Distribution Arrangements.
• Conclusions.

3
Introduction

• Electricity is vital for a mine to function.
• Supply must be reliable and efficient.
• Two main types of distribution are used
• Radial,
• Secondary-selective.

4
Design

• Reliable, efficient, safe, and at the cheapest
  cost.
• Future expansion plans of the mine and the type
  of equipment must be considered.
• Will a utility be available or does the mine have
  to generate its own power?

5
Power Distribution Equipment

• Generation facility.
• Portable and unit substations.
• Main substations.
• Switch-houses.
• Mine power centres.
• Distribution (conductors connectors).

6
Utilities

• Often the main supply.
• Transformer steps up the voltage for
  transmission.
• Transmission voltage may go straight to a machine
  or to a distribution transformer.

• Load variations can effect other equipment
  ie.electric excavator.
• Remote site may need to generate its own supply.
• Emergency supply for ventilation fans and other
  essential equipment.

7
Substations

• Reduce incoming voltage for distribution.
• Some mines may require more than one.

8
Substation Components
9
(No Transcript)
10
Metal-clad Switchgear

• Has a number of components
• Switches,
• Circuit breakers,
• Relays etc.
• Enclosed in sturdy metal box.

11
Mine Power Centres

• Converts the distribution voltage to one that can
  be used by machinery.
• Underground units protected by steel cabinet.
• Surface unit usually on trailer and fenced off.

12
Distribution

• Distribution Equipment
• Cables and couplers,
• Trolley lines,
• Overhead powerlines.
• Radial and secondary-selective are the most
  common arrangements.

13
Radial Distribution

• Cheap to install.
• No duplication of equipment.
• Easily expanded.
• If primary component fails, entire system stops.
• Popular in strip mining operations.

14
Radial Distribution
15
Secondary-Selective Distribution

• Essentially two radial systems joined together.
• More reliable and flexible than radial.
• If component fails, bad part of circuit can be
  shut off.
• Maintenance can be carried out, but non-essential
  loads must be removed due to reduction in
  operational capacity.

16
Secondary-Selective Distribution
17
Conclusions

• Power system must be reliable, efficient, safe,
  and at the cheapest cost.
• Design must take future expansion and equipment
  selection into account.
• Utility capacity must be considered.
• Two most common distribution systems in mines are
  radial and secondary-selective.