Customer Case
Vindhyachal Thermal Power Station
I/O upgrade of demineralized water treatment plant with minimum downtime (India)
Customer Profile
The Vindhyachal Thermal Power Station, located in the Singrauli District in the state of Madhya Pradesh, is owned and
operated by National Thermal Power Corporation (NTPC), India’s largest power company. Vindhyachal is one of the
largest power stations in the country, with an installed capacity of 3,760 MW.
Customer objectives
The Challenge:
NTPC sought to upgrade the existing operating system because of the obsolescence of its existing L&T I/O cards and the
lack of support. An upgrade was essential because a failure could impact the entire power plant which continuously feeds
four units of 500 MW each. The major challenge was to complete the entire upgrade in 72 hours.
Customer benefits
Smooth operation of the plant after removal of the legacy L&T cards
> Improved services due to the homogeneity of the system
> Extended warranty and enhanced life span from Schneider Electric
> Ease of maintenance and spare parts inventory
> One point of contact for all support
This project was the first of its kind, initiated by Net Cascade with guidance from Schneider Electric, in a super critical
situation. The original supplier of the PLC system, was unable to commit to executing the project in the allotted time frame
of 72 hours.
In the end, the project was completed and handed over in only 52 hours and subsequently ran for 15 days on a trial basis
without any deterioration in the plant’s performance.
The success of this project will pave the way for Schneider to carry out such jobs at various other NTPC Locations.
Schneider
Solution overview
The Solution
NTPC engaged Schneider Electric partner Net Cascade Automation Pvt. Ltd. to implement a solution. The existing L&T
I/Os were replaced with Quantum
I/Os after assuring a mechanical fit in the existing panel as well as:
> Mapping of over 1000 I/Os with the existing Quantum CPUs done with new addresses
> Corresponding addressing modified in SCADA
> Supplied I/Os were pre-wired at I/O end using multi-core cables
Onsite alterations included:
Cabling both power & control: Old cables were removed and replaced with 20 core armoured cables for I/Os and coaxial
cables for control on S908 protocol
HMI screens: Modifications to the screens according to the new address references
Control loops: The control loops were reconfigured to make redundant architecture and communication with the SCADA
stations.
Redundancy: Redundant configuration was achieved with new I/O family
The Quantum Concept Series CPUs -140CPU113 03 communicated with Schneider Electric’s I/Os over S908 protocol with
the help of the coaxial cables, taps, splitters and line terminator while the L&T I/Os were dismantled and the new wiring
pattern was implemented from the cards to particular TBs/relays without changing the field wires.
Address references were cross checked and the Logic and SCADA were remapped wherever needed.
Products & Systems
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