Measurement tools for Smart Grid stability and quality

Short Name: SmartGrid II, Project Number: ENG52
Wind turbine and power station

Stabilising electricity grids: Providing measurement tools for Smart Grids


To help meet European emission reduction goals, vastly increased renewable power generation capacity will be needed, necessitating considerable changes to electricity supply network instrumentation and control systems. Much of this generation will be intermittent, bi-directional and will require ‘smart’ management of supply and demand to maintain grid stability, and avoid blackouts due to poor power quality (PQ) issues. Phasor measurement units (PMUs) are a technology designed to monitor energy flows related to power demand and generation and enable improved grid management. However, improved calibration and traceability of PMUs will be needed for network operators to be confident that these complex instruments perform reliably.

 

This project developed technologies and standards to monitor the stability and quality of electricity supplies. Building on outcomes from the EMRP project Metrology for smart electrical grids, SmartGrid II delivered a new understanding on how PQ issues spread across a working electricity network.

 

The Project:

  • Developed and implemented a prototype PQ location method using new PMU algorithms in a transmission grid, that determined the source of large disturbances in PQ.
  • Designed and implemented a fully operational, standards-compliant, automated PMU calibrator, with uncertainties 10 times lower than existing commercial products.
  • Characterised the voltage transformers used by PMUs and PQ instruments using a new technique for on-site measurement of voltage transformers, that reduced measurement uncertainty by two orders of magnitude.
  • Developed three new ways to measure grid impedance, a metric important for Smart Grid state estimation models and PQ relating to high-frequency interference on grids.

 

Delivering impact
On a renewable-rich smart grid on Bornholm Island, Denmark, measurements were made using six installed bespoke PMUs with PQ capabilities, applying new algorithms, that located issues for network operator Østkraft. Data was presented on network operating conditions, that combined with weather data, was able to
estimate renewable generation levels.

 

A method for calibrating PMU reporting signal delay, important for power system protection and control was enhanced after the end of the project by Strathclyde University, enabling passive real-time operation, with any PMU, and without changes to PMU hardware or software. This method offers very high accuracy while requiring only low-cost additional hardware and open-source software.

 

The new methods for measuring grid stability and power represent breakthroughs for removing causes of power loss, grid control malfunctions, interference, shortened asset life and malfunctions of connected products. The measurement infrastructure now exists for incorporating reliable and accurate PMUs, capable of advancing the development of Smart Grids, and helping to meet carbon emission reduction targets.

 

The EMPIR project, Standard tests and requirements for rate of change of frequency measurements in smart grids addresses the need for greater standardisation in these measurements for power quality in electrical grids.

Project website
Publications
Accurate Numerical Modelling of MV and HV Resistive Dividers
2017

IEEE Transactions on Power Delivery

Asynchronous Phase Comparator for Characterization of Devices for PMUs Calibrator
2017

IEEE Transactions on Instrumentation and Measurement

Frequency calibration of MV voltage transformer under actual waveforms
2016

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Smart grid power quality and stability measurements in Europe
2016

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Accurate Phase Calibration of PMUs and PMU Calibrators
2016

Proceedings of the Conference on Precision Electromagnetic Measurements 2016

Real-time compression of IEC 61869-9 sampled value data
2016

2016 IEEE International Workshop on Applied Measurements for Power Systems (AMPS)

Power quality propagation measurements in smart grids
2016

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Dynamic algorithms for PMUs — Methods for improving the signal processing effectiveness
2016

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

The calibration of static and dynamic performances of PMUs
2016

Proceedings of the International Congress of Metrology

Application of PMUs for monitoring a 50 kV distribution grid
2015

Proceedings of the 23rd International Conference and Exhibition on Electricity Distribution (CIRED) 2015

Measurement Infrastructure to Support the Reliable Operation of Smart Electrical Grids
2015

IEEE transactions on instrumentation and measurement

Frequency calibration of voltage transformers by digital capacitance bridge
2015

2015 IEEE International Workshop on Applied Measurements for Power Systems (AMPS)

Analysis of the propagation of Power Quality phenomena using wide-area measurements
2015

Proceedings of the 23rd International Conference and Exhibition on Electricity Distribution

The calibration of static and dynamic performances of PMUs
2015

17th International Congress of Metrology