McMillen Jacobs Associates
is a highly technical frm
engineering, and construction
services to the hydropower,
heavy civil industries.
Proud NHA Member
In addition, at the time of erection the original equipment manufacturer used an aluminum and copper link assembly with bi-metallic
strip for the transformer low voltage side bushing connection. In this
arrangement, the bi-metallic strips were found in overheated/burnt
condition during inspection. A modifcation was made by removing
the bi-metallic strips and using a single fexible copper link. Tis
eliminated hot spots due to the aluminum–copper joint and resulted
in more reliability of the transformers.
Te performance of a hydropower plant is judged by the fnancial (proft
earned) and operational results, i.e. annual electricity generated and
annual Plant Availability Factor (PAF) achieved against the normative
PAF fxed by the electricity regulator (CERC in India) for each type
of hydro plant under its jurisdiction. Te plant is to generate as per
the generation schedule fnalized by CERC on a daily basis.
Te operational performance mostly depends on the high standards
of maintenance done (preventive maintenance and maintenance as per
the maintenance schedules formulated by the power station).
Te preventive maintenance and innovative modifcations discussed
above signifcantly improved performance of the Chamera III plant. As
Figure 1 (see page 6) shows, forced shutdown hours dropped from 251.07
in 2012 to 2013 to 4:14 in 2016 to 2017. PAF increased from 71.51% in
2012 to 2013 to 95.8% in 2016 to 2017. (Generation was lower in 2016
to 2017 due to a planned outage for repairs in February and March.)
Te power station will receive annual fxed charges of INR4 billion if
a PAF of 85% is achieved, with greater benefts if PAF exceeds 85%. ■
Kaul, Prashant, “Maintenance/Repair – 231MW NHPC Chamera-III Hydroelectric Power
Station,” Proceedings of HydroVision International 2017, Penn Well, Tulsa, Okla., 2017.
Jain, CK, Arnaud Legrand and Prashant Kaul, “Commissioning a Himalayan Medium-Head
Hydropower Project: The Chamera III Experience,” HRW-Hydro Review Worldwide,
Volume 22, No. 5, October 2014.
Prashant Kaul is general manager of the Chamera III plant for NHPC Limited.
Proper attention to maintenance activities has significantly reduced
needed work at the Chamera III powerhouse.