Valmet’s automation system controls hydropower generation in the Himalayas

The river Sewa originates from glacier waters at an altitude of 4200 meters in the Himalayas. The 53-meter-high concrete gravity dam lies in the beautiful natural valley of the Sarthal hills. From the dam site, water flows through a long horseshoe-shaped tunnel of over 10 kilometers to the power plant located near the junction of the Sewa and Ravi rivers.

The annual total electricity generation capacity of the plant is 533.52 GWh. The state of Jammu and Kashmir (J&K) is entitled to get 13% of the total generated electricity free of charge. J&K is rich in hydropower potential, the majority of which is as yet unharnessed. Below the power plant, the Sewa joins the Ravi at an altitude of 578 m. The area, known as mini-Switzerland, is also popular with tourists; close to the site is the beautiful Lake Khajjiar.

Installed technology

The main subcontractor and power generation technology provider for NHPC is Bharat Heavy Electricals Limited (BHEL), one of India’s leading companies in power generation technology. The power plant comprises three 40 MW vertical Pelton turbines with a rated net head of 560 meters. To control the hydropower generation process, BHEL uses Valmet Automation’s DCS technology.

Process control system

Process control is implemented using Valmet’s system hardware and software. It features automatic start-up and shutdown of the turbine and generator, initiation of necessary measures in case of a fault, and interlocks for operation and plant devices. In addition, the system includes process signals, alarms and events for display on the HMI system (Human Machine Interface). The HMI system provides the necessary controls at each control location to enable reliable operation of the installed technology.

The automatic start-stop control is configured as a sequential control system. Following the selection of an operating target, the system transmits commands to the process step-by-step in accordance with a program and supervises their correct execution. With regard to system reliability, Petri Tiihonen, Manager, Strategic Accounts at Valmet Automation, points out that “When designing Valmet’s DCS systems for hydropower plants, we take into special consideration the most essential factors, namely reliable operation and a minimized number of shutdowns.”

Strong foothold in India

Valmet Corporation is a well-established company in India, with close to 1000 employees in total. In the process automation sector, the power generation industry forms the most important customer group for Valmet Automation. So far, Valmet’s DCS control systems have been installed for power generation of over 120.000 MW worldwide. Furthermore, Mr. Tiihonen explains that Valmet’s DCS technology has achieved a market share of over 65% in the Indian power generation industry and the latest development, Valmet DNA, is growing its share in new installations. Being selected as a process control provider for the Sewa II project is an indication of the trust in Valmet Automation’s process knowledge and high profile in the Indian market.

For more information please contact:

Petri Tiihonen, petri.tiihonen at valmet.com