Metering the accurate value of energy exchange is one of the vital issues in power system operation and planning, and also power market billing. The main responsibility of the electrical energy metering bureau is planning, managing and supervising the operation of the energy metering systems in Iran power system. The main components of energy metering system can be classified as follows.

Energy measuring equipment:

The digital energy measuring equipment which are classified as grid type meters with 0.2% accuracy class are provided, installed and operated with the aim of equipping different energy exchange points of the national grid such as power plants, cross-border electrical energy import/export, and electrical energy consumption. A typical overview of metering points in Iran national grid is shown in figure 2.

Data gathering and processing systems:

In order to provide the energy reports for different energy exchange points, it is necessary for all measured data to be processed, validated, and stored by the energy metering systems. All of the required processes are performed in several subsystems as follows:

• Data gathering subsystem

  This subsystem collects the measured data from various metering points by taking advantage of the world's latest software and stores it in the Iran national energy metering database. Among the features of this system is managing more than 50000 electric meters, supporting DLMS standard protocol, and establishing the connections to digital meters through different communication media such as fiber optic, ADSL, and GPRS.

• Data process and validation subsystem:

  This subsystem is in charge of evaluating the data accuracy by performing some crosscheck rules and preparing the validated data to be used in form of energy reports.

• Data storage subsystem:

  The data storage subsystem through required hardware resources provides the necessary capacity to store the data for the period of 10 years.

• Data reporting subsystem:

  This subsystem is designed in order to provide different reporting services for metering system users in the form of hourly, periodic, managerial, and web service reports. In this subsystem despite appropriate flexibility in regard to user’s accessibility, data confidentiality is fully protected.

Communication infrastructure of energy metering network:

The first priority of energy metering network communication infrastructure is using of power industry fiber optic. In areas where fiber optic infrastructure is unavailable, other communication media such as ADSL, GPRS, PSTN, and GSM are utilized.