Established in 1960, Central Power Research Institute, popularly known as CPRI, has been India’s backbone when it comes to testing of electrical equipment. Over the years, CPRI has contributed immensely to meeting India’s requirements for testing of electrical equipment; it has also served overseas clients. In this exclusive interaction with T&D India, V.S. Nandakumar, Director-General, CPRI, discusses how the institute is gearing up to meet the upcoming needs of the power sector that is not only growing in terms of capacity but is also getting technologically complex. An interview by Venugopal Pillai.
Please tell us in brief about CPRI’s current infrastructure in terms of testing of high-voltage equipment.
Central Power Research Institute (CPRI) is an autonomous body established by Ministry of Power, Government of India, to strive for carrying out applied research in electrical power, acting as a third party independent laboratory for evaluation of electrical equipment, offering field testing as well as consultancy services and conducting training programs. The institute has expertise to offer single roof services in a wide ranging spectrum of electricity generation, transmission and distribution.
CPRI houses unique facilities for evaluation of EHV/UHV equipment going into the 800kV/1200kV system. Test facilities have been created for short circuit testing of transformers/switchgear; transmission line towers & accessories; power cables; capacitors; material characterization including CRGO; insulators and lightning arresters; conductor vibration studies; transformer oil; relays, energy meters and smart meters; refrigerators and air conditioners; domestic appliances including LED and solar photovoltaic lighting systems.
Special services are offered for seismic qualification of electrical equipment, real time digital simulator for power systems studies and communication protocol for power system automation.
We note with appreciation that CPRI has also conducted tests on 1,200kV equipment for the Bina UHVAC line. Please tell us more on the achievement.
CPRI is a member of the Steering Committee for PGCIL’s most recent project on development of the 1,200kV National Test Station. CPRI’s UHV Research Laboratory at Hyderabad has successfully completed consultancy work with respect to 1200kV UHVAC system and tested many 1,200kV lines and substation equipment which are in operation at 1200kV National Test Station at Bina, Madhya Pradesh.
To name a few assignments:
- Study of corona performance of octagonal conductor bundle in a corona cage. Here, the sub-conductor spacing for 1200kV octagonal bundle conductor was optimized based on the corona performance in a corona cage.
- Air insulation studies for 1200kV UHVAC transmission line: A study on optimization of conductor to tower air insulation clearances for adoption in 1200kV AC transmission lines using eight BERSIMIS conductor bundle was successfully conducted.
- Voltage distribution studies on 1,200kV single ‘V’ insulator string: Optimization of grading ring size was successfully completed on 1,200kV single ‘V’ string consisting of 46 numbers of 420kN disc insulators with nine different grading rings by measuring voltage distribution across insulator discs.
To enhance the testing capacity, CPRI shall be installing two more 2500MVA short circuit generators within a timeframe of 2-3 years.
What new facilities are being planned for high-voltage and extra high-voltage equipment?
CPRI has been augmenting and setting up new facilities as per the requirement of the power sector. Gaps have been identified in high voltage and ultra high voltage test facilities, which would further enhance utilization of CPRI facilities by Indian manufacturers. Following important facilities are being established/upgraded in Bangalore, Bhopal and Hyderabad:
- Augmentation of high power short circuit test facilities by installation of two additional 2500 MVA generators with associated equipment at High Power Lab, Bangalore
- Establishment of 40kA temperature rise test at HPL, Bangalore
- Establishment of 350 MVA online short circuit test station at UHVRL, Hyderabad and Nashik
- Augmentation of test facilities at STDS, Bhopal
- Upgradation of HV/UHV test facilities at Bangalore
- Establishment of short circuit testing transformer, excitation system for existing generator at Bangalore
- Augmentation of pre-qualification test facilities at Bangalore
UHVRL, Hyderabad is coming up with an indoor laboratory. Partial discharge tests on HV/EHV equipment up to 800kV rating, accuracy tests on instrument transformers up to 800kV rating, RIV test and wet tests on all HV and EHV equipment can be conducted in this new laboratory. The laboratory has also established +1200kV, 200mA HVDC test system.
Despite having a sound base for testing of high-voltage equipment, India is still reliant on foreign laboratories like CESI, KEMA, etc. What is your view?
As per our knowledge, CPRI caters to requirements of almost all tests required by manufacturers. We are given to understand that acceptability of certificates issued by Indian laboratories for export market is an issue, which is being addressed through industry association IEEMA.
To enhance the testing capacity, CPRI shall be installing two more 2500MVA short circuit generators within a timeframe of 2-3 years. The capability level for short circuit testing shall be enhanced to threefold, which will be more than sufficient to meet the international requirements ahead of the expected power sector growth in different countries.
CPRI facilities have been utilized by Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, Sri Lanka, Korea, Japan, Europe etc.
CPRI is amongst the co-promoters of National High Power Test Laboratory Pvt Ltd (NHPTL). How do you think would NHPTL alter the EHV testing landscape in India?
Earlier, high voltage testing of EHV equipment and short circuit testing of transformers only up to 84 MVA, 400kV class was feasible in the country. For higher rating of transformers, manufacturers and utilities had to depend upon the short circuit test facilities of KEMA Laboratory in Europe.
After the commercial operations of NHPTL in Bina that began in July 2017, all the power transformers rated up to 400kV class, 500 MVA and 765kV class, 315 MVA can be tested within India. From July 2017 till date, in NHPTL there were nine EHV transformers of various category of utilization viz generator transformers, station transformers with dual secondaries and auto transformer with tertiary that have been tested out of which one transformer rating was single phase 765kV, 85 MVA and the other transformers are of 400kV class whose power rating, ranging from 120 MVA to 315 MVA, and single phase 270 MVA, 400kV/27kV. Earlier, testing of such transformers was not possible and it was a great challenge as enormous test source was required.
With this new test facility in Bina, the hardship of sending large EHV power transformers to overseas test laboratory is mitigated. Further, NHPTL test facilities will enhance design improvement and pave way for better development of EHV transformers being manufactured by various Indian manufacturers. NHPTL test facility is boon for testing of number of EHV large power transformers of different rating being put into service by Power Grid Corporation of India, NTPC and other utilities in India. Testing in NHPTL labs will help end users to get quality EHV equipment.
We understand that CPRI also caters to testing requirements of foreign clients. Tell us more.
CPRI has expanded its clientele during the last decade. CPRI is a Short Circuit Testing Liaison (STL) member, accredited by ISO/IEC 17025, Intertek, INMETRO, Brazil and many other national/international bodies.
The services offered to the Indian power sector are also being sought extensively by overseas manufacturers. CPRI facilities have been utilized by Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, Sri Lanka, Korea, Japan, Europe etc.
Besides certification, consultancy and training services are also utilized by utilities and industries of countries in Middle East, South East Asia, Far East Asia and Africa. Today, CPRI services are being sought by countries like USA, Australia, New Zealand and many other countries.
What collaborative role have foreign labs like CESI and KEMA played in enhancing the testing infrastructure of CPRI, for HV equipment?
CPRI earlier had collaborations with laboratories like CESI, Italy EDF, France and EPRI, USA for R&D cooperation and information exchange programmes in the early 1980s.
Presently, CPRI is interacting with CESI, Italy as they have been appointed as technical consultant for executing the following projects by CPRI:
- Augmentation of high power short circuit test facilities by installation of two additional 2500 MVA generators and establishment of 40kA temperature rise test at Bangalore
- Establishment of 350 MVA online short circuit test station at Hyderabad
The equipment identified to be procured under the above projects and the specifications will be finalized in consultation with CESI, Italy.
Conversely, please discuss how other entities are benefiting from consultancy services being rendered by CPRI, in the field of testing of power equipment.
Consultancy is one of the important activity through which the expertise and facilities in the Institute are applied for explicit studies, analysis, design etc.
CPRI has been offering consultancy in the areas of diagnostic & condition monitoring of HV substation and power plant electrical equipment, site testing of transformer oil, power system studies, real time simulation of power system controls, protection audit, RLA and R&M of thermal and hydro power plants, energy audit, power system automation/distribution automation, smart grid, pollution mapping studies etc.
As part of consultancy assignments, this year training and plant optimization program has been offered by a team of CPRI engineers at Hwange Thermal Power Station (4×120 mw + 2×22 0mw) in Zimbabwe.
Many consultancy assignments executed are related to problem solving and product development for power utilities and industry. The expertise has resulted in improving the reliability and safety of the power system network.
What is your view on the availability of skilled manpower when it comes to a sophisticated field like research and testing?
The power sector is at a fast-growing pace and the capacity of generation is increasing day-by-day to meet the growing demand. It is not only anticipating additional capacity, but also expecting more competitive technologies both in terms of lower operating cost as well as lesser environmental pollution. In order to comply with the growth rate, it needs both skilled manpower for operating those plants as well as highly qualified research personnel to sustain a steady growth in technology development. The manpower requirement for research centers are very specialized as fundamental research calls for a lot of dedication, clarity of concept, innovation and patience.
With the continuous guidance and support of the Ministry of Power, Government of India, CPRI has drawn its plan of action for create and upgrade testing facilities in consultation with utilities and IEEMA.
India’s power transmission infrastructure is growing substantially, and that too with emphasis on high and extra-high voltages. In such a scenario, how do you see prospects for CPRI in the coming years?
The power sector in the country has been witnessing rapid growth with massive capacity addition to generation. This will create added supply and demand. As a result, CPRI will continue to focus more on its key areas of activities such as routine and type testing, R&D on complex and diverse problems faced by the electrical power industry, consultancy projects, third-party witnessing services for the equipment procured by utilities, and training programs for the enhancement of skilled manpower in materials, high power, high voltage, thermal engineering, energy efficiency and new & renewable power-related activities.
With the continuous guidance and support of the Ministry of Power, Government of India, CPRI has drawn its plan of action for create and upgrade testing facilities in consultation with utilities and IEEMA. The vision of CPRI is to emerge as the single largest service provider under an umbrella of laboratories, globally. By regularly addressing the increasing needs of the power sector, upgradation of technical manpower skills and focusing on customer satisfaction, CPRI will strive towards efficiency improvement and achieving goals of future demands in India and abroad.
