An in-depth view of how automation plays a huge role in operation of small hydro power plants in India
The Indian subcontinent is bestowed with potential to generate hydro power. In India the ministry of new and renewable energy is responsible for developing Small Hydro Power (SHP) projects up to 25 MW station capacities. Most of the potential for hydro power generation lies in the Himalayan states for river based generation and in other states for canal based projects. Currently, India is exploring the limitless opportunities in hydro power generation with setting up of small hydro power plants up to 25-30 MW capacity being the preferred choice as compared to large hydro projects.
India’s focus on small hydro power plantsThe Ministry of New and Renewable Energy has introduced the Small Hydro Power (SHP) programme to promote power generation from renewable sources of energy. Small hydro has been identified as a critical source of energy which can help in resolving the crisis of energy which the country currently faces. With small hydro projects being developed by both public and private players the ministry’s aim for SHP’s installed capacity of 7,000 MW by the end of 12th Five-Year Plan doesn’t seem far enough.
Hydro power is the world’s most widely used form of renewable energy. It produces about 20 per cent of the world’s electric power and accounts for almost 90 per cent of electricity generated from renewable sources. It is clean, sustainable and emission-free. Commenting on potential of hydro power generation in India Ahmad Khan, VP, Power Generation – Automation, ABB says, “Among all the non-conventional and renewable energy sources, small hydro represents the ‘highest density’ resource and stands in the first place in generation of electricity. Small hydro power is one of the focus areas of power generation since it requires low investment and is one of the most appropriate renewable energy sources to meet increasing energy demands.”
While answering to a query on whether India is in the right direction in operating small hydro power plants, Pankaj Mishra, Industry Business Segment Head – Water and Waste Water, Schneider Electric India said, “Yes, India is on the right track as we have enough of water resources which can be used to generate power. But still lot of emphasis on standardisation is required on improvement, reliable technology, stock production and control for micro and small hydro plants.”
While talking on penetration of automation in this sector, Neeraj Kala, Assistant Manager (System Engineering), Flovel Energy Pvt Ltd opines, “In small hydro power plants the automation is only limited to powerhouse. They do not have efficient staff to operate the plants which results in generation loss.”
Experts feel there are many flaws which are hindering growth. According to Nagendra Sharma A, Manager – Proposal Engineering, BFL Hydro, “Still there is huge untapped potential available which is under the licence of influential people who are neither developing nor selling the licence of potential. The power purchase tariff is not changing as per market inflation. The process of approvals and financing is taking long time from concept to completion. All the equipment is designed with higher margins because of old regulations.”
Relevance of automation in small hydro plantsWith manual systems, the operators need to constantly monitor routine round the clock activities related to plant operation, equipment start-stops, handle disturbances and emergency situations, maintain logs and reports etc. which often lead to fatigue and loss of efficiency resulting in increased human errors. The plant load factor gets affected, leading to poor utilisation of installed capacity.
“To have optimum reliability and availability of the control system we need automation in place so that man-less operation can be done and increase power generation by efficiently controlling and man monitoring the whole system help us in maintaining the hydropower plant better,” remarks Mr Mishra.
Automation in small hydro plants can drastically enhance operator effectiveness and help take quick actions. According to Mr Sharma, “Automation can reduce man power and improves accuracy of operation. Preventive and scheduled maintenance will decrease the down time.”
Implementation of an automation system improves the productivity and operational efficiency of a hydro power plant. Automation is the best answer for eliminating the issues encountered in manually controlled units. All relevant information, alarms and events related to the process and control system hardware are made available at one place. Mr Khan says, “Centralised monitoring helps utility owners to effectively monitor the operation of multiple facilities from one place and enables them to take quick, well-informed decisions that have bearing on the overall productivity and profitability.” ABB has delivered the Symphony Plus system at the Ranganadi Hydro Electric plant in Arunachal Pradesh in India, a solution that improves operator efficiency in terms of greater awareness of plant behavior, faster decision and preventive maintenance actions due to the availability of alarm management, trip analysis details, trends etc. on Symphony Plus Operation HMI system.
Difference of automation between large and small hydro power plantsThere is a lot of difference between the automation used in large hydro plants as compared to small hydro plants. There is a structural difference between small and big hydropower the first is mainly decentralised the later is usually utilised by big structures, which have usually massive environmental impacts.
Speaking on the different ranges of systems involve in the hydro power plant automation Mr Sharma says, “Large hydro power plants participate the grid regulation and hence governing plays a major role for frequency regulation while, small hydro do not participate in grid regulation only load control and CAM control would be sufficient. Since most of small hydro projects are run off river the turbine required to operate at peak efficiency based on head and flow variation.”
Small hydro plants are mostly located in remote areas with difficult access, in such case the automation system should be easy to operate and maintain by the staff which may not be very skilled. “A simple, rugged and maintenance free Symphony Plus total plant automation system with remote control features will be highly desirable in the case of these small size plants,” assures Mr Khan.
He adds, “In case of large plants, the cost of automation systems could be a small fraction of the total investment, whereas in the case of small hydro plants, this could be significant. Therefore a more economical solution optimally meeting the automation requirement will be necessary. There is also a tendency to club sequencer, governor, and protection and excitation system in a single panel, where as in large hydro plants these are conventionally separate systems.”
The basic difference is when designing small and micro hydropower plant all the production and electrical control are designed within the single UCB and there are not as many panels as compared to larger power plants. “Basically in NCC, in production panels and in panels for auxiliary controls there are metering and other breakup panels for which we have large number of cuticles for that larger power plant but in a micro power plant everything can be controlled within a single panel. In small power plant you may do it with two or three electrical panels,” explains Mr Mishra.
Advancement of protection systemsControl and protection systems in small hydropower plants have seen considerable advancements in the recent years. The latest state-of-the-art easy to use PC-based HMI (human machine interface) systems offer many benefits to hydro power plants. Microprocessor-based digital control system with the associated high performance controllers and high density Input/output hardware has drastically reduced the space required for installation of the automation system. “The control hardware is rugged, reliable and is easy to maintain with online replacement feature. The old hardwired systems have given way to software configurable DCS systems utilising powerful function control blocks and libraries,” says Mr Khan.
Now monitoring of protection relays (IEDs) can be done. The latest numerical protection relays combine multiple functions into a single unit. These relays communicate over IEC 61850 protocols. The relays support self-calibration and advanced self-diagnostics. Old electromechanical or electronic relays are being now progressively replaced with latest intelligent electrical devices (IED’s) and modular platform hardware which are easily monitored and diagnosed remotely from HMI.
When we say Programmable Logic Controller (PLC), we can put the manual control combined into a smart controller so that all the decisions are made by the central CPU and on the backend of it there is a program that can be written and designed as per the required logic so it’s a smart interface that does all the jobs and takes care of all the control points and on front end of the control panel there is SCADA where we can see what is happening on the backend. All operations like turbine and generator control, synchronisation, auxiliary control, gird control, protection and level monitoring all is integrated into single PLC.
“We don’t need an additional controller for the individual control which in-turn helps in reducing the size of UCB and also we can have a multiple user SCADA which can give interface to so many users,” says Mr Mishra. This system is not available in manual system or with PLC in which we can have better control.
Automation products/solutionsAccording to ministry of new and renewable energy there are about 27 equipment manufacturers of small hydro power turbine who fabricate almost the entire range and type of SHP equipment listed in MNRE. Manufacturers’ capacity is estimated at about 400 MW per year.Schneider Electric produces hydro turbine governors, Programmable Logic Controller (PLC) based automated grid control integrated with level and SCADA based remote monitoring and control for multiple hydro power plants to serve the hydro power sector in India.
While ABB’s product portfolio covers the entire automation needs of a hydro power plant, including control, instrumentation and electrical systems solutions. ABB’s latest and state-of-the art Symphony Plus Control System is a rugged, low maintenance automation system with extensive features specifically for Hydro solutions. Profibus, HART, IEC- 61850, IEC-60870-5 and Modbus TCP communication protocol. Symphony Plus HMI system is designed for high performance human machine interface, integrated operations, seamless life cycle management, and information management, alarm management, security, process optimisation, flexible, scalable and fault tolerant design.______________________________________…a more economical solution optimally meeting the automation requirement will be necessary.
Ahmad Khan, VP, Power Generation – Automation, ABB______________________________________
Automation can reduce man power and improves accuracy of operation.
Nagendra Sharma. A, Manager – Proposal Engineering, BFL Hydro______________________________________________________________
In small hydro power plants the automation is only limited to powerhouse.
Neeraj Kala, Assistant Manager ( System Engineering), Flovel Energy Pvt Limited____________________________________________________
India is on the right track as we have enough of water resources which can be used to generate power.
Pankaj Mishra, Industry Business Segment Head – Water and Waste Water, Schneider Electric India _________________________________________________
An in-depth view of how automation plays a huge role in operation of small hydro power plants in India