National metering system for electricity wholesale market

Short description:

The electricity metering management system goal is to make acquisition of electricity metering in the exchange points defined through Electricity Metering Code, periodic transmission, their processing and displaying at central level - MMS (Metering Management System). At central system level, through specialized calculation equipment, all information is acknowledged, sorted, analyzed and reported. At local level electricity metering and index transmission in binary format are performed via active & reactive electricity meters whose information is taken over, concentrated & sent to MMS using appropriate date concentrators and GSM/mW/F0 support modems according to the communication network available at the location level. During 2003-2004, ISPE prepared the performance of local metering sub-systems in electric substations where accurate metering of electricity transmitted is required.
Metering for settlement of accounts:

between power generator and power "transmitter";
between power "transmitter" and power "distributor";
between power "distributor" and eligible consumers.

The system is performed by means of independent Landis + Gyr sub-system with technical features in compliance with ANRE Code for electricity metering. For Transelectrica substations, the designed work included: replacement / completion of metering units (current & voltage transformers, metallic supports & foundations included) decentralized meters installation (electric, withdrawable) in specially conceived panels, installation of data concentrators and local serial communication network. Within power substations of Termoelectrica & Hidroelectrica the designed work only included implementation of local metering sub systems. For the civil work part of this project, in order to reuse existing elements, it was required to find special solutions to adapt/reinforce existing foundations for the erection of the new latticed metallic supports and where the specialty technical survey recommended, special solutions to adapt/reinforce existing centrifuged reinforced concrete supports. For each situation, it was demonstrated the appropriate behavior of the foundation - support - apparatus assembly at all stress categories. For the primary equipment erection part solutions were found to minimize outage and material costs.
For the secondary circuits’ part, considering the project object - accurate metering - calculation applications were developed to evaluate operation conditions, possible adjacent correction measures.

Services offered:

The project developed in four stages:

stage 1 - investigation on site, construction parts survey and existing installations surveying finalized with a report approved by the Final Client CN Transelectrica;
stage 2 - basic design, technical requirements;
book for execution and lists with work quantities for each location;
stage 3 - detail design for equipment implementation in each power substation in this project;
stage 4 - "as-built" documentation for construction book.

Other services:

preparation of manufacturing documentation for locally delivered panels
client technical assistance during project running.

Main technical features:

Metering sub-systems are provided in about 110 locations, including some 650 metering points, in the area of Transelectrica at all voltage levels (low, medium, high and very high voltage).
The meters are connected in diagrams with 2 or 3 currents & 3 voltages (4 wires) and meter active / reactive powers received / delivered and calculation of loss where such is the case
The metering transformers provided (current, voltage or combined current-voltage) have an additional second for accurate metering.

Estimated economic efficiency:

The metering system implementation provides necessary information regarding electricity quantities passing through exchange points as well as on interconnections with neighboring power systems. Information is useful for the following entities: Commercial operator - electricity market manager, Transmission operator. The metering system has the following important advantages:

allows effective electricity market operation;
allows more accurate short, medium and long term consumption forecasts;
allows optimization of performance and operation of transmission, distribution and NPS networks based on technical & commercial criteria.

Country and location:

All over Bucharest, Romania.

Start date / commissioning date/ implementation stage :

March, 2003 - stage 1 - April, 2004
- stage 2 - March, 2005

Client:

Romenergo SA
Final client: SN Transelectrica SA.

Implementation stage:

all meters transmit data to central system (MMS)
90% of primary equipment are erected and comissioned.

Associated companies:

DADA SRL for expert appraisement of existing construction elements

ISPE