Power System Operation System

Damian Flynn is introducing his group of Power System Operation System

challenges in operating future power systems incorporating variable and/or uncertain renewable energy sources

Flexibility needs of the power system

Ability of individual components to contribute towards system support services

generation, loads and storage

load following, spinning reserve, inertial support

System impacts

User comfort for discretionary loads, thermal plant ramping requirements, state of charge of electric vehicles


Eamonn Lannoye : Power System Flexibility


FLEXIBILITY

is the ability of a power system to use its resources to meet changes in net load

   
Measure Flexibility


Generation planning including flexibility

Decision variables to build units in unit commitment

Include needs for ramping and sub hourly intervals

Insufficient Ramp Resource Expectation

Analysis of system dispatches

Include operational issues at planning stage

Simplified Flexibility Assessment

Conclusion

Flexibility of increasing importance in power systems

The inclusion of flexibility at the long-term planning stage may ensure real time operability

A number of values are required in order to fully characterise the flexibility of a system

Dr. M. Reza Bank Tavakoli : System Stability: Load Inertia Estimation

Major increase in renewable power penetration

Simulation studies assess future system security

Network loading

Fault levels 

Voltage control and stability requirements

System flexibility requirements

   Dynamic, transient and small signal stability

 System wide dynamic inertia including load

   
Load inertia is really important in our system. 

What is inertia?

System dynamic inertia

Rotating mass stored energy

Limits to rate of change of frequency (ROCOF)

Load inertia

Part of system dynamic inertia

Frequency sensitive loads 

Distributed across the system

Varies with time of day/week/year

Conclusion:

Event-based methodology can be deployed for system-wide inertia estimation

Load inertia varies significantly with time of day, week and year

More HVDC connections → reduction in system inertia 

Future changes in load type(s) requires ongoing estimation of load inertia

Need for a real-time system wide inertia estimator based on on-line measurement quantities (future work)


Lisa Ruttledge Wind Generation Flexibility


Conclusion:

Wind generation can provide flexibility

Differs from conventional generation

Geographical distribution

ROCOF protection/generation issues

Tuning of active controls

Over frequency events


Eamon Keane: Power System Services From EVs
Ancillary services are “those services, aside from energy, which are necessary for the secure operation of the power system


Categories:

Frequency regulation

Contingency reserve

Spinning vs. non-spinning

Flexible ramping reserve

Conclusion:
EV availability for contingency reserve depends on time of day/week/year and range anxiety of users
Network restrictions at higher EV penetrations
Benefits if charged in sympathy with system ramping needs
System ramping periods less predictable going forward
Tariffs/real-time pricing to incentivize behaviour

Energy Network

Dr Andrew Kean are introducing is group. They focus their research on Smart Grid.
"How do we address the changes on the grid? We are really focus on infrastructure and to maintain the supply demand reliable and consistent."
The distribution systems generation weren't designed originally so we are to implement the structure to support it.  They work to flexible demand and EV Vehicles and how to optimise the resources.

Jerry O’Sullivan present Peter Richardson Integration of Distributed Energy Resources in Low Voltage Electricity Networks

Existing network not designed to accommodate flexible load and EV o microCHP

Impact Assessment to investigate the impact of increasing penetration of DER units.
Test residential network and use deterministic analysis to assessed network limits.

Controlling charge for high penetration of EV utilise network sensitivities to determine optimal charging rates.

Voltage drop against the uncontrolled charge of EV vs controlled charge.

Controlled Charge:

Larger number of EVs allowed to charge compared to uncontrolled case

More efficient use of network capacity increases total energy delivered

Defer costly upgrading of network infrastructure

Do we need a centralised controlled?

CONCLUSION

High penetrations of uncontrolled DER may cause operational issues on existing LV networks

Centralised control of DER units

More efficient use of existing network capacity

Allows for higher penetration of DER devices

Local control method

Requires only local network information

Less communications infrastructure

Mario Džamarija : Optimal Operation of Distributed Wind Generation


Objective:

Medium scale -> medium voltage network, 38 kV

Non-firm generation -> curtailment

Planning

Operation

Distributed generation (DG) reactive power (Q) resource


Operation

AC Optimal Power Flow tool (AC OPF)

Nonlinear Programming

Planning AC OPF model

Operation AC OPF model

Conclusion:

59% increase in energy harvesting from non-firm DWG

92% extra cap. (27 MW) utilized, 96.7% wind energy exported

REQUIREMENTS: Q absorption of WF’s to deal with V rise

SIDE-EFFECT: High wind power triggers simultaneous binding V and I constraint

hinders from using full Q capability

Paul Cuffe: Reactive Support from Distributed Resources

Transmission reactive planning considers siting and sizing resources

Reactive power in distribution studies used to avoid constraints and minimise losses

What reactive capability can DG provide at the transmission level?

What capability is required by transmission system as conventional plant is displaced?

Conclusion:

Distributed reactive power capability
- Comes “free” with many renewable generators – need to harness it
- Contingent on distribution system conditions
- Needs to be included in transmission system planning
- Effective characterisation identifies potential voltage problems

Future work

-System unit commitment including regional reactive power constraints

-Enhanced passive voltage control settings for DG

Dr Eknath Vitta: Transient Stability Impacts from Distribution Connected Wind Farms

Ireland has approximately 50% of wind generation in the distribution system

What are the stability impacts of the distribution connected wind?

How can the wind be controlled to improve the stability of the transmission system?

the objective:

As the reactive power control strategy of the wind farms changes:

How is the stability of the conventional synchronous units impacted?

How does the system response to a fault change?

Overall, the goal is to assess the dynamic impact of voltage control at the distribution level and how that impacts the stability of the system at the transmission level

Conclusion:

Distribution connected wind with power electronics can be beneficial to system performance

The unique characteristics of the network help damp voltage drops

Improving the system voltage directly impacts the rotor angle stability of conventional synchronous units in the system

Transmission connected wind needs to provide control otherwise system security decreases

Energy Economics

Claudia Aravena highlight the the importance of economy in the energy system some issues are:

¨     Energy Policy

¨     Climate Policy

¨     Aspects of electricity market design

¨     Renewable energy technologies

¨     Renewable integration

¨     Interconnection

¨     Behavioural aspects of energy demand

¨     Electric vehicles

¨     Energy Efficiency

¨     Policy instruments (e.g. subsidies, taxes, incentives)

Claudia is introducing Muireann Lynch:

Optimal interconnection and renewable targets in North-West Europe

Interconnection it is really important to increase the capacity factors and diversify supply and increase the renewable penetration and arbitrage opportunities

from an EU prospective we can increase investment in less-favourable areas

Research Questions:

Where should we build interconnection?

How do renewable targets change the story?

How to get best value from assets?

We set Objective function and constraints. Assume new interconnection have a capacity of 1 GW.

Iterative Approach to find the optimal connection.

We run different Scanarios to find the optimal interconnection

Results:

Conclusion

Interconnection has value primarily as facilitator of variable renewables.

Design of targets has an impact on the value of interconnection – and indeed renewables

Amy O’Mahoney: The Merit Order Effect of Wind

This paper considers the cost savings arising from wind generation through the meritorder effect in gross pool electricity markets

She is explain the Merit Order Effect on the electricity Market. The Case Study is Ireland.


The aim is quantify the cost savings arising from wind generation through the merit order effect in gross pool electricity markets


Results:

◦Estimated savings €141 million

◦Total market dispatch  €1,484 million

◦Without wind, prices would have been 12% higher

System Group lead by Prof Mark O'Malley

Paddy Teahon is introducing the system group lead by Prof Mark O'Malley

Dr Niamh Troy is presenting: Wind Penetration and Power Cycling

Cycling is really important because wind energy has a not deterministic production and also for the market competition.  She modelled a multi-mode operation of combined-cycle Gas turbine.

She use the Wilmar model to allow a multimode function implementing a virtual capacity factor by this combined mode. Then she integrated the increasing wind production.Then she compared the multimode operation with the normal operations of the power plants.

Cycling affect in a positive way the overall performance of the power plants.
These are the result found after three years of test of power plants, we can reach the 30% of saving.

Conclusion:

Increasing wind penetrations shown to increase generator cycling :CCGTs identified in many wind integration studies as being forced out of merit

Modelling various configurations of CCGT benefits the CCGT by allowing a new opportunity to be dispatched and benefits the system through increased flexibility and availability of replacement reserve.

Modelling cycling costs dynamically allows depreciation over time to be represented.

Explicit modelling of cycling costs is shown to reduce cycling operation, thereby reducing cycling costs

Results from test system show modelling dynamic cycling costs alters merit order over time.




Colm Lowery: Uncertainty & Forecast Error Statistics

Schedule Available plant to meet forecasted demand lowest cost/highest reliabilityWind Power adds another stochastic element

It is important to have a scheduling model to:

Optimization model – minimises expected costs (fuel, carbon, startup) subject to load and constraints

It is possible to identify the shape of errors in scheduling through a moment matching.
Setting an Objective Function and some Costraints.

Modelled variance as percentage of true variance

Conclusion:

System behaviour changes with known error information

The type and the accuracy of provided information matters

Forecast error knowledge changes the utilization of different generator categories

Different utilization patterns impacts System Planning

Aonghus Shortt: The Future Grid: Quantifying & Responding to Variability


It is difficult to model the scheduling with the increase on Wind penetration

In the real world the modelling could take from 20 minutes to 1 second with the alghorithm developed  we could reache the throshold of 20 millisenconds.


Quantifying the impact of Wind and compare with the benefit of wind. Negative impact of Wind are the start costs and it doesn't coincide with the demand.
Higher level of wind the plants will not start and so we have to evaluate the 

System benefit Ratio= reduction in total generation cost : increase in total capital costs

With this Ratio we can evaluate the benefit of increasing wind penetration in each country depending also from the correlation between the wind blowing and the actual energy demand.


Evaluation of Electric vehicle impact on the point of view of benefit and costs.


Current Work on Design Long Term Generator Plan: we want to encourage unit with less capital cost.


so what are Compensation Mechanism


Conclusion:

Net value of wind - Variability mitigation through EV -Reform of compensation mechanism

ERC Research Seminar

9:05 - The seminar just started and Michael Tutty introduced the Minister for Communications, Energy and Natural Resources - Pat Rabbit
09:10 - ERC should expand with the support of industries. ERC is involved in one of the most important work for our future: energy and smart grid. This is important not only for our country Ireland but also for all the world. Research and especially Energy Research is fundamental. Here the work is really supported by industries and company and this is an indicator of the quality of the work. He was fascinated that last christmas the 42% of the energy was produced by renewable energies.
ERC work will influence the EU energy policies and the government will focus on the energy research on  grids and smart grids. We cannot live in a fuel paradise for too long. There are talents here that can lead the world in the good direction.
09:20 - Prof O'Malley Mark - there are 50 people online and welcome all.  We are here to focus on the work of the students. There are several companies international that follow our group.


NEW FEATURES:
Electricity and data  the word is going to integrate energy. System integration is the key of the research for the next future!

There are different groups at the ERC  the first group will present will be the

System Group

"Shaping the Grid" is setting the begin.

This is a special day, the day when this adventure through energy and a sustainable future begin.

It is not a random day, today is the 22th of May when the ERC  (Electricity Research Center) will present the research symposium : "Shaping the Grid".

In this symposium will be highlighted how our research is important worldwide for the future of the energy. It is not important because we are the most brilliant researchers on the earth but because in what we do we put all our effort and we try to be over the top.

Well my role in this group is just to let you know what is going on and what are the results we and the worldwide colleagues are achieving.

We will talk about energy inventions and cool gadgets you can find on Internet . We also will give the opportunity to our readers to comment and submit their ideas.

During the symposium I will highlight interesting comments and interventions and I will upload some videos on our green video bar.

I know this is just a begin so there will be not so many readers but believe me, step by step, day by day the blog will be more interesting and you will be excited to receive the last news straight from science.

So are you ready to follow?

For the one interested I have set up different automatic ways:

1) you can submit you email

2) RSS feed

3) just come to our website weekly to see what is going on.

Now before starting with the event I would like to write a post about me, just few lines to not bored anyone.

Welcome all to the Next Energy.