ENGN8831
Smart Grids 1

Paul Scott

Outline

Future Grid Challenges

• Managing infrastructure costs
• Integrating non-dispatchable generation
• Integrating distributed energy resources

Residential Bill Breakdown

AER. State of the energy market 2015. Technical report, Australian Energy Regulator, 2015.

Retail Prices

AER. State of the energy market 2015. Technical report, Australian Energy Regulator, 2015.

Total Demand

AER. State of the energy market 2015. Technical report, Australian Energy Regulator, 2015.

Peak Demand Ratio

AER. State of the energy market 2015. Technical report, Australian Energy Regulator, 2015.

Generation Source

AER. Generation capacity and output by fuel source, 31 March 2017. URL https://www.aer.gov.au/wholesale-markets/wholesale-statistics/generation-capacity-and-output-by-fuel-source. AER reference: D11/2285335[V2].

Distributed Generation

Australian PV Map

Electric Vehicles

Nissan Leaf 24 kWh, Tesla Model 3 up to 75 kWh

Home consumption around 16kWh per day

Smart Grid

An electricity network that uses advanced information and communications technologies to automate the production, delivery and consumption of electricity

Spectrum of Network "Intelligence"

Advantages

Helps to overcome future challenges plus...

• Creates new markets for participants
• Cheaper to operate and maintain
• Improved reliability

Sensors - Intelligence - Actuators

Technologies

Meters

Voltage/Current Transformers

• Measure AC voltage and current
• Can be used to activate protective equipment

Cheap Sensing

• Current
• Temperatures
• Sag

Technologies

Generators

• Governor set point for real power
• Exciter DC voltage to adjust reactive power

Transformers

• Tap ratio to maintain voltage
• On-load automatic or off-load manual tap changing
• Phase shifting transformers to control flows

Switchgear

• Breakers, reclosers, sectionalisers
• Interrupt and isolate faults
• Reconfigure network
• Automatic, remote or locally activated

FACTS Devices

• Source/sink reactive power
• Power electronics with capacitors/inductors
• Mechanically switched capacitors

Inverters

• Convert DC to AC for PV and batteries
• Power factor control

Batteries/Electric Vehicles

• Smooth out consumption and PV generation
• Electric vechicles to increase loads

Technologies

Dispatch Engine

• Decides how the wholesale market is cleared
• Used alongside contingency simulation,
• and FCAS markets

Dispatch Engine

Dispatch Engine

Distribution Management System

• SCADA
• State estimation
• Load flow studies

Energy Management Systems

• Communicate with smart devices
• Coordinates devices to reduce costs for house
• Responds to price signals or requests from network

Communication

• Power-line communication
• Mobile phone network
• Fibre optics (bundled with conductors)
• Wireless (ZigBee and WiFi)
• Consumer internet connections?

Dynamic Line Ratings

Can we push more power on our networks by safely operating closer to the network limits?

Motivation

• Better utilisation of infrastructure
• Reduce need to invest in upgrades

Description

• High flows heat lines causing sagging
• Wind, ambient temp, radiation have large impact
• Significant dynamics
• Idea: Real-time line rating based on a combination of direct measurements and modelling

Characteristics

Yi Yang; Harley, R.G.; Divan, D.; Habetler, T.G., "Thermal modeling and real time overload capacity prediction of overhead power lines," Diagnostics for Electric Machines, Power Electronics and Drives, 2009. SDEMPED 2009. IEEE International Symposium on , vol., no., pp.1,7, Aug. 31 20096-Sept. 3 2009

Usage

• Dynamic trip currents for circuit breakers
• Dynamic warnings for DMS system
• DMS to take preventative action

Self-Healing Grid

What if the grid could automatically reconfigure itself to isolate a fault and resupply power?

Motivation

Utilities pay the regulator huge fines for downtime, and blackouts have huge opportunity costs for those affected

Description

• Power supply restoration is the central problem
• Take corrective action in under a minute
• Remotely operable switches make this possible
• Crews still go out and physically fix equipment

Overview

Overview

Overview

Automation

We can turn this into an optimisation problem:

• Maximise number of loads served
• By switching lines and redispatching generation
• Subject to network constraints

Demo

DER Coordination

Can we coordinate millions of DERs to efficiently operate and support the network?

Bruny Island Problem

• Install PV-Battery systems in up to 40 island homes
• Offset expensive diesel generation used to relieve congestion and manage voltages

Technologies