Success Story: Commissioning Of Phasor Measurement Units (PMUs) For A Central Transmission Utility

The 2012 grid collapse in India resulting from excess power usage by some states prompted the authorities to conceptualise the idea of ‘One Nation One Grid’ by monitoring and analysing the real-time power usage data at the regional and national level.  

To achieve this, Synchrophasor technology is widely used across India for real-time data collection and analysis that aids in improving grid reliability and efficiency. Synchrophasors are time-synchronized values that represent the magnitude and phase angle of the sine waves found in electricity. These Synchrophasor values are measured with the help of high-speed monitors called ‘Phasor Measurement Units (PMUs)’ that take accurate measurements of the phase angles, voltage and frequency that is time stamped using high-precision clocks. PMU measurements play a pivotal role in offering actionable insights into network-level grid stability or stress issues.

In this post, we will cover how SCOPE’s services vertical – ISOSCELES Sales & Services Pvt. Ltd. (ISSPL), successfully commissioned over 1000 PMUs for India’s Central Transmission Utility (CTU).

ISSPL’s Mandate

ISSPL was roped in by a leading PMU OEM to flawlessly commission the PMUs for the Utility’s 70 Substations.

The primary task was to install PMUs at 70 Substations to seamlessly monitor over 1000 EHV Feeders in the CTU’s grid network. The installed PMUs had to be correctly configured and commissioned to accurately capture the inputs from Current Transformers (CTs) and Potential Transformers (PTs) and record the status of Circuit Breakers and trip signals of Protection Relays. All measurements had to be accurately time stamped by ensuring that the PMUs were time-synchronized with the GPS installed at each Substation.

 Challenges Faced

1. Cabling

At many locations, the cables were placed in the ceiling duct of the main control room that warranted additional civil work to be done. On the other hand, at a few locations, the space constraints in the existing cable trench posed a challenge in laying the extra cables.

2. Geo-location

The high-altitude of many Substations located in Himachal Pradesh posed health challenges to the ISSPL team. Each team member had to undergo various stringent pre-medical checkups to ensure that they were in optimal health to work in Himachal’s hostile environment. 

3. GPS Signal Quality

At a few locations, the ISSPL team had to install the PMUs at a depth of 300 ft. underground. At this depth, it was challenging to ensure reliable and strong GPS signal for time synchronization. However, this challenge was ably tackled with the ISSPL team’s engineering expertise that resulted in flawless GPS signal acquisition.

The Outcome

ISSPL team’s ingenious PMU execution has ensured that the Synchrophasor data from each of the 1000+ EHV Feeders is seamlessly and continuously transmitted from the 70 Substations to the CTU’s Regional HQ by utilising the Utility’s Wide Area Monitoring System (WAMS) based on IEEE C37.118 Synchrophasor measurement and communication protocol.

This in turn has helped the CTU’s Regional Load Dispatch Centre to receive and synchronize the data received from multiple PMUs into its Phasor Data Concentrator (PDC) software and produce a real-time analysis of grid stability.

The key driver in the successful execution of this project was ISSPL team’s engineering expertise and quick-learning abilities that ensured that all the PMUs were accurately configured and installed with minimal technical support from the PMU OEM. The invaluable experience gained from this project has further honed the team’s skills resulting in ISSPL providing technical maintenance and troubleshooting services to the CTU since the past 2 years.

To learn how ISSPL team’s engineering expertise can help your Utility, please visit https://www.scopetnm.com/substation-services or write to us at marketing@scopetnm.com.