inertia estimation methodologies vs measurement methodology: … · 2019. 5. 14. · inertia...

Inertia Estimation Methodologies vs Measurement Methodology: Impact on System Stability

CONFIDENTIAL - All Rights Reserved © 2019. Reactive Technologies Limited/Finland OY.

Chris Kimmett

Commercial Director Networks

[email protected]


About Reactive

• Reactive Technologies is a UK & Finland based energy tech company leading the transition to a lower carbon energy future with its unique telecommunications technologies.

• With 140+ patents granted, an R&D team comprised of ex Nokia experts and two technological world firsts achieved, Reactive’s innovations are disrupting the status quo.

• Key Technology offerings:Ø World First Inertia Measurement Service - GridMetrixØ PPA, Flexibility and Optimisation Services

• Investors:

Overview of Reactive Technologies

Locations

The Risks of Not Measuring Inertia

• Managing Risk & Better System SecurityØ Understanding regional inertia and the risk of the

electricity system ‘islanding’.Ø Volatile frequency can lead to loss of embedded

generation and large generation, understanding leads to better services to cope with this frequency.Example: South Australia blackout in 2016

• Balancing & Capital Cost. To manage risk of low inertia, grids can purchase new balancing services (e.g. fast frequency response) or invest in capital (e.g. synchronous condensers), costs which can be optimized through better measurement.Example: National Grid spend >£100m p.a. managing inertia

• Integration of renewables. Ultimately the re-positioning of units to resolve constraints or to increase levels of inertia will lead to a reduction in the level of renewables on the system which is becoming politically unacceptable. South Australia blackout in 2016 & National Grid ESO escalating inertia cost

For island grids, inertia is critical for managing frequency and for highly interconnected grids an understanding of regional inertia is important for managing the risk of islanding and grid-wide oscillations

£30.2m £30.7m

£59.2m

£100.0m

£0.0m

£20.0m

£40.0m

£60.0m

£80.0m

£100.0m

£120.0m

2015/16 2016/17 2017/18 2018/19

UK Cost to Manage Inertia


Inertia Measurement – UK Case Study

First power system inertia measurement demonstration project.

• In July 2017, National Grid ESO and Reactive Technologies successfully demonstrated that the latter’s critical data measurement and analytics service (GridMetrix®) was able to accurately measure power system inertia for the first time.

• Five 600kW fully resistive load banks (red pins) and 30 measurement units (yellow pins) were installed across GB in about a month, including commissioning and integration.

• The controllable load banks were used to modulate the signal to a minute degree which were then measured by Reactive’s measurement units and analysed by the GridMetrix cloud platform who produced inertia measurements.


Inertia Measurement – UK Case Study Findings

Using Reactive Technologies’ signalling and measurement technology in a blind test, inertia was directly measured on the GB grid.


Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7

Measured inertia (proposed method)

Inertia from synchronous generators only

Inertia estimate using demand scaling factor

• Total modulator size ~3 MWØ 20-60 GW systemØ i.e. 0.01% - 0.005%

• More accurate at lower inertia times

• Bank holiday shown on Day 6Ø Green area

highlights potential cost saving

Ø Red area highlights risk areas

• In March 2019, Reactive Technologies completed a 1.5 month project with a TEPCO to demonstrate GridMetrix on a small, controlled island network.

• A load bank was used to create periodic, small power disturbances in the grid. This modulation signal created a small frequency movement in the power system which was recorded by 14 of Reactive’sextensible measurement units (XMUs) installed across the network which then reported the data to the GridMetrix® cloud via a secure internet connection.

• Blind trials were carried out between Reactive’smeasurements and the utility’s estimates of known generators.

Inertia Measurement – Japan Case Study

To the rest of the power system

Load bank

Diesel generators

Power meter XMU


Inertia Measurement – TEPCO Case Study Findings


GeneratorUtility-supplied Inertia (MWs)

RTL measured Inertia (MWs) Difference %

1 0%

2 0%

3 -20%

4 -6%

5 0%

TOTALS -4%

• Total modulator size ~0.3% - 0.15% of total system

demand

• Accuracy verified against specific generators (table below)

Ø Showed two generators’ H-values to have been

recorded as too low in models

Ø Utility models are optimistic in this case!

Inertia based on H summation Measured inertia

Conf

iden

tial

Conf

iden

tial

Inertia Estimates vs Measurement – Approach Overview

Method

Continuousresults

TransmissionInertia

Distributioninertia

Accurate Power

Measurement

Enough data to

understand inertia

patterns

Accurate RoCoF

Measurement

Summing inertia across all synchronous generators

✓ ✓ O N/A O N/A

Calculating RoCoF during large frequency excursions

O ✓ ✓ O O O

Estimation based on power events throughout the day

✓ ✓ ✓ O O ✓Reactive’s real-time inertia measurement ✓ ✓ ✓ ✓ ✓ ✓

Reactive Technologies’ patented method


[MWs]

Based on the Swing equation

GridMetrix – Benefits Summary

GridMetrix empowers TSOs with the inertia visibility they need to continue to operate their systems safely and cost-effectively within the new, more volatile energy mix.

• Increased Renewables Integration: Having an accurate view of inertia will allow TSOs to decrease their need to curtail intermittent generation in lieu of fossil fuels and ultimately accommodate more renewables.

• Decrease or Deferred spend: By better understanding their grids, TSOs will be able to make more informed procurement decisions on balancing services and long term reinforcement.

• Maintain Security of Supply: Having real time visibility of events propagating through their networks will allow TSOs to take optimal mitigation/recovery steps and continue to keep the lights on.

The expected return on investment for GridMetrix is 1 year.



Thank youIf you would like to learn more, please get in touch:Chris KimmettCommercial Director [email protected]

inertia estimation methodologies vs measurement methodology: … · 2019. 5. 14. · inertia...

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