NAILA

BRANCH:EEE

OVERVIEW• The Indian Grid is characterized

by widely dispersed generation and load points. Because of this there is large amount of power flow in the inter-regional grid in the east-west, east-north and the north-west corridors. Growth of Independent Power Producers is changing nature of these power flows.

• State, Regional and National Load Despatch Centers as mandated by the Electricity Act 2003 carry out the supervision and control of Indian electricity grid and its complexity is increasing day by day.

A WAMS can be defined as a system that takes measurements in the power grid at a high granularity, over a wide area, and across traditional control boundaries and then uses those measurements to improve grid stability through wide area situational awareness and advanced analysis.

To be able to monitor, operate and control power systems in wide geographical area, WAMS combines the functions of metering devices with the abilities of communication systems

A WAMS process includes three different interconnected sub-processes :

Data Acquisition

Data Transmitting

Data Processing

Measurement systems and communication systems together with energy management systems perform these sub-processes, respectively.

Measurements in WAMS systems are implemented by special-purpose equipment – PMU which determines phase angles and amplitudes of currents and voltages, frequency, power etc. in various parts of a power supply system. All measurements are synchronized by means of GPS accurate within 1 micro second.

Data from PMU with time stamps are transferred to WAMS systems server on which the special software is installed, which provides data acquisition from all PMU`s in system and makes their processing, calculations, storage, and also, displays in real-time power system state parameters and delivery of messages and signals.

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GPS

Ethernet

PMU

PMU

PMU

hp Workstation i2000

hp Workstation i2000

Phasor Data

Concentrator

EMS

Database

ApplicationsCommunication Standards

IEEE C37.118.2

IEC 61850-90-5

ICCP

The Phasor Measurement Unit (PMU) is a microprocessor based device that uses the ability of digital signal processors in order to measure 50/60Hz AC waveforms (voltages and currents) at a typical rate of 48 samples per cycle (2400/2880 samples per second).

A PMU by our convention measures bus voltage (phase or sequence) and all 3-phase line currents on all branches (transmission lines and transformers) emanating from the substation along with the phasor angles

PDC is designed to process streaming time-series data in real-time and Measure the data gathered with GPS-time from many hundreds of input sources and then time-sorted.

The main functions of a PDC are: to gather data from several PMUs, to reject bad data, to align the time stamps, and to create a coherent record of simultaneously recorded data. As a consequence, a snap-shot of phasors of the measured area can be obtained

High bandwidth communications guarantee that all phasor data can be transmitted to PDCs without any

packet drops.

GPS SYNCHRONIZATIONPMUs rely on a GPS time signal for extremely accurate time-stamping of the power system information where power system reliability is important!

Being the new evolving technology, Synchrophasors initiative in India was taken up by Power System Operation Corporation Ltd. (POSOCO) in pilot manner in the year 2010 by installing 4 PMUs in Northern Region.

Subsequently all these pilot projects have been integrated and formed into a national level synchrophasors project which is

under operation with data availability from about 60 PMUs. The PMUs installed in all the five regions of the Indian grid were at

strategically selected locations like generating stations, load centre substation and interconnecting substations

Currently, the PMUs are installed on the pilot/ demo basis. The pilot/demo projects have been extremely beneficial in obtaining the knowledge of difficulties involved in installation and communication of PMUs.

With this platform, India is now fairly ready for large scale deployment of PMUs across the country to attain maximum benefits using synchrophasor data.

Thank You !!!

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