Power engineers are electrical engineers who specialise in areas where high voltages of electricity are generated, transmitted, or used.
In Australia, power is generated for most customers at major coal-fired or hydro generating stations. There are also growing numbers of wind and solar generating installation.
The power engineers' roles in power generation can be to:
- determine the correct operating conditions for the power station
- monitor the performance of the generators and associated equipment
- design and implement a 20kW solar panel system for remote supply, or
- design the protection requirements to connect a 600kW wind turbine.
Major users of power - such as city office buildings, factories, long-haul railways, and mining drag lines - need reliable, cost-effective supplies of power. Power engineers work with these major users to design, implement, monitor, and protect their power supplies.
Specialist fields for power engineers in power applications include power electronics. This field uses high-power electronic devices and computer controls to enable energy from DC (direct current) sources, such as fuel cells or solar cells, to supply energy to the main power grid. Power electronics are also used to generate variable frequency voltages that will change the speed of large motors, such as those that drive electric locomotives.
Transmitting and distributing power
Electrical power leaves power stations at very high voltages of about 500 kilovolts (kV). This is transmitted over networks of lines to cities and towns. Within cities and towns, substations reduce the voltage in stages - 132 kV, 33kV, then 11 or 22kV, and finally to the 240 volts for use in homes and business.
Power engineers are employed in line design, line maintenance, incident investigations (eg. storm damage), and in developing design and maintenance standards and network management strategies. Working in transmission and distribution, power engineers also deal with the general public, local government, and state government agencies regarding the impact of lines on the environment, the selection of line routes, and managing the vegetation (trees) near power lines.
Major projects that power engineers are employed to design and construct include transmission lines, zone substations, communications and SCADA systems. It could also include a major refurbishment of existing plant. The work activities include design, construction and project management. Often, power engineers are engaged in several projects at one time, so good time-management and prioritising skills are necessary to deliver projects on time.
Operating power networks
Power engineers are responsible for the safe operation of power networks. Typical activities for power engineers include:
- day-to-day management of the network
- writing and authorising switching programs
- providing safe access to parts of the network for repair and maintenance teams
- managing outages (power losses)
- developing switching procedures
- developing network operational standards and manuals.
Engineers in network operations have daily contact with asset management staff, and provide design staff with valuable feedback on network improvements.
Planning and developing systems and networks
Power engineers are responsible for the system design of the network so that it has the capacity to deliver a high-quality supply of power to customers (as required by the National Electricity Code and Electricity Regulations). Here, power engineers are interested in supply quality parameters, such as voltage levels, and voltage fluctuations, reliability (i.e. duration and frequency of power failures).
Specialist investigations by power engineers will often be required to determine the stability of the network under specific power demand conditions, network configurations, and fault conditions. Power engineers can use sophisticated computer software to model the network and produce analyses of load flows and faults.
Substation design and maintenance
Substations are installations where electrical current is reduced in stages from the high voltage levels (up to 500kV) needed for transmission, down to a lower voltage (132kV and below) for distribution around towns and cities. Power engineers are employed to:
- design or maintain substations
- investigate incidents (lightning strikes), and
- develop the design and maintenance standards, and associated asset management strategies.
Power engineers working on substations also need people skills because they deal with the general public, local government, and state government agencies regarding the impact of substations on the environment and the general community. Power engineers will often develop the capital and maintenance works program, and the budgets and project business cases.
Test and commissioning power plants
Power engineers are responsible for ensuring that any electrical plant that is energised (switched on) is fit for the purpose, and safe. This involves testing the equipment before it is energised to ensure that it is fault free and operates correctly when required. In this field, power engineers work on all electrical equipment - from power transformers to sophisticated communications and protection equipment - and advise the design and asset management engineers of all field modifications carried out as a result of any testing and commissioning.
Design of power equipment
Power engineers can be engaged in the manufacture of transformers, generators or switchgear and oversight the process from design to testing. Other aspects where the power engineer has significant input, can be in the design of electricity meters or protection equipment.