Digital metering, PMU applications and protocol enhancements with real-time IEC

Sampled values (SV) from non-conventional instrument transformers – or Low Power Instrument Transformers (LPIT) – offer the potential for new industry applications. These applications exploit digital real-time IEC 61850 communication on metering, grid control and the efficiency of the IEC 61850-SV protocol & are currently being investigated as follows.

Coordinator: Enrico Mohns

 

Metering

Non-conventional digital LPITs can be used for metering purposes. However, the effects of this digital approach on the metering chain needs to be understood, including the impact of the digital time-stamped representation of signals, the algorithms for power calculation, the various Analogue-to-Digital (A/D) converters (e.g. delta/sigma, SAR, etc.), and the different types of sampling clocks. Finally, metering products that use the SV protocol are already on the market, but there is a need to independently evaluate their performance to fully support their successful market introduction. Project research will address these industry needs.

Grid control

Modern monitoring of the state and dynamics of transmission systems is presently realised through Phasor Measurement Units (PMUs). However, time and measurement integrity must be assured. These instruments typically use analogue inputs, but the availability of IEC 61850‑9-2 compatible digital inputs offers significant advantages, simplifying PMU design and sharing inputs with other applications. Nevertheless, using digital inputs can also further complicate the measurement uncertainty, as well as affecting latency, both being critical barriers for many proposed real-time PMU applications to be adopted across the industry.

The project will therefore take a look at how suitable present standards for all-digital PMUs are represented by voltages and currents, and researchers also aim to quantity the impact of this approach on PMU measurement uncertainty and latency. Guidance future standards and validation methods will additionally be provided.

Efficient digital substation measurement data management

There is potential to develop new methods for effective data reduction that have no impact on measurement uncertainty. These methods could significantly reduce the communications bandwidth and system-wide latency of digital substations, in turn improving overall efficiency and supporting new real-time applications. Moreover, the use of these data reduction methods could lead to additional functionality for measuring PQ parameters. As an example, if it is possible to compute the voltage and current emissions in the frequency range of 2 - 150 kHz directly inside the SAMU, the processed and compressed data could then be transmitted via the same communication bus as for the SV data. This would ensure the same performance as conventional PQ measuring devices, without needing very high sampling rates (300 kHz or higher) and data transmission rates.

For more information, see the project webpage >>

 

Parent project
Short Name:FutureGrid II,Project Number:17IND06

Participating Euramet NMIs and DIs

INRIM (Italy)

METAS (Switzerland)

MIKES (Finland)

PTB (Germany)

UME (Türkiye)

VSL (Netherlands)

Other participants

Alma mater studiorum Università di Bologna (Italy)
ComSensus, komunikacije in senzorika, d.o.o. (Slovenia)
Fundacion Circe Centro de investigacion de recursos y consumos energeticos (Spain)
Ricerca sul Sistema Energetico – RSE S.p.A. (Italy)
Synaptec Ltd (United Kingdom)
Università degli studi della Campania Luigi Vanvitelli (Italy)
University of Strathclyde (United Kingdom)

Information
Type
EMPIR
Field
Industry
Project type
Joint Research Project
Status
completed
Call
2017
Duration
2018-2021