Newcastle division

Engineering studies

Personal & Public Transport 1 June 2015

Power generation/ distribution

• The electricity power system: – Generation – Transmission – Distribution

330 kV or 132 kV

33 kV to 110 kV

6.6 kV to 22 kV

230 V & 400 V

Power generation/ distribution

Generation 23 kV AC

Transmission 330 or 500

kV AC

Transmission Substation 132 kV AC

Distribution 132 kV AC

Distribution Substation

33 kV Distribution

33 kV AC

Zone Substation 11 kV AC

Customers

500/ 330 kV 132 kV 33 kV 11 kV - Aluminium smelters

- Distribution companies - Major users such as steel plants

- Medium sized industry - RailCorp

- Small sized industry - Homes (via 11 kV/ 415 V transformers

Power generation/ distribution • Generation:

– Thermal: • Usually achieved by a fuel heating water to

produce steam to drive a turbogenerator • Fuel can include:

– Solar * – Geothermal * – Nuclear – Biogas (agricultural waste, manure, municipal

waste, plant material, sewage, green waste or food waste) *

– Natural gas or coal seam gas – Coal (black or brown)

* Renewable

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Power generation/ distribution

Coal-fired Power Station

Power generation/ distribution

Eraring Power Station

Power generation/ distribution

Nuclear Power Station

Power generation/ distribution

• Generation: – Sustainable:

• Solar thermal • Solar voltaic • Wind turbines • Tidal turbines

Power generation/ distribution

Solar Power Station

CSIRO Newcastle

Power generation/ distribution

Wind Power Station

Power generation/ distribution

Tidal Power Station

Power generation/ distribution • Transmission:

– Voltage transformed to extra high and ultra high voltages for transmission across long distances

– Transmission energy losses are lower at higher voltages (P = I2R)

– Extra High Voltage (EHV) > 300 kV – Ultra High Voltage (UHV) > 800 kV – Energy is transmitted as AC or DC:

• AC for distances up to around 500 km • DC for distances greater than 500 km (usually greater

than 1000 km) or for submarine cable transmission or asynchronous connections

Power generation/ distribution • Transmission:

– Large power generators feed into the transmission system (330 and 500 kV in NSW and Victoria)

– Energy is transmitted over transmission lines – Voltage is transformed down to sub-transmission

and distribution voltages for local distribution (132 kV in NSW) at transmission substations

Power generation/ distribution

NSW Transmission System (2011)

Power generation/ distribution

Generation Step-up Transformer (Eraring Power Station)

Power generation/ distribution

EHV Transmission Lines (500 kV Victoria)

Power generation/ distribution

Transmission Tower

Power generation/ distribution

• Transmission tower components: – Insulators and insulator strings

Ceramic

Glass

Power generation/ distribution

• Transmission tower components: – Insulators and insulator strings

Insulator String

Modern Long-rod Insulator

Power generation/ distribution • Transmission tower

components: – Conductors & conductor bundles

Aluminium Conductor Steel-Reinforced (ACSR)

All Aluminium Conductor (AAC)

500 kV Conductor Bundle

Power generation/ distribution • Transmission substation:

Power generation/ distribution • Transmission substation:

330 kV Feeders

Circuit Breakers

330/ 132 kV Transformers

330 kV Busbar 132 kV Busbar

132 kV Feeders

Power generation/ distribution • Distribution:

Power generation/ distribution • Distribution:

Power generation/ distribution • Distribution:

Power generation/ distribution • Protection systems:

– Billions of dollars of plant in the NSW power systems

– Assets must be protected against damage from: • Environmental stresses such as lightning, wind, trees,

fire, snow • Component failure • Man induced failures such as diggers, crains

Power generation/ distribution • Protection systems:

– Lightning Protection

Power generation/ distribution • Protection systems:

– Surge Arrestors

Power generation/ distribution • Protection systems:

– The simplest protection against overload or over current is the fuse

– Fuses are used in distribution systems, domestic premises and appliances

– They are also used to protect high voltage equipment such as transformers and motors

Power generation/ distribution • Protection systems:

– Fuse time-current characteristics

Power generation/ distribution • Protection systems:

– Earth leakage (such as a residual current device, RCD)

– Earth fault – Overload – Inverse time overcurrent – Instantaneous overcurrent

– These protection schemes normally operate a

circuit breaker

Power generation/ distribution • The future power system?

– Energy technology? – Role of the power system