MP085A Synchronisation of smart meter voltage measurement periods

The expectation of Electricity Network Parties during the development of the smart meter technical specification was that the average Root Mean Square (RMS) voltage readings from smart meters would be measured across a consistent period. For example with the default being for an average to be made across a 30 minute period starting on the hour and again on the half hour. This is not an explicit requirement codified in Smart Metering Equipment Technical Specifications (SMETS) or Great Britain Companion Specification (GBCS).

Without voltage measurements being made in a consistent way, Electricity Network Parties must either:
i) make conservative, less efficient analysis assumptions to account for the lack of data alignment, or
ii) recreate synchronised data by downloading high granularity (for example minute resolution) data and calculating the required data.

Investigations during the Refinement Process found the issue affecting existing installed meters more complex than initially envisaged. This could result in a lengthy lead time for implementation where meter Manufacturers could potentially still produce Devices that do not commence average RMS voltage readings on the hour. Therefore, it has been agreed that there should be two separate solutions to address the issue;
• MP085A (this modification) – a Technical Specifications document change for meter Manufacturers to ensure a predictable approach for when newly manufactured Devices commence average RMS Voltage Measurement Period readings; and
• MP085B – a solution for meters that are already installed if SEC Parties request that already installed Devices adopt the desired functionality by a set date.

The Proposed Solution is to amend SMETS to provide a consistent approach for all Electricity Smart Metering Equipment (ESME). The solution is to ensure that the Average RMS Voltage Measurement Period starts or resumes from a predictable point in time, allowing automatic realignment of a Device’s measurement periods with those of other ESMEs. This will allow DNOs to make full use of the Average RMS Voltage Profile Data Logs for remote comparison across all of their ESMEs.

Electricity Network Parties
Meter Manufacturers

SEC Schedule 9 'Smart Metering Equipment Technical Specifications'