Automation has become an integral part in power sector to meet the growing demand of enhancing plant performance through dependable and predictable operations to generate the highest economic returns. Today’s advanced computer hardware and software technologies enable optimising all the elements of a power plant and operating the whole plant as a single unit with the objective of maximising the value of the plant’s assets. Thus, with the advent of automation, monitoring and controlling of a power has become more integrated and just a mouse click away!
Talking about the role of automation in optimising power plant performance, RK Chugh, President Elect, Indian Electrical & Electronics Manufacturers’ Association (IEEMA), said, “We all know that energy systems are changing – fundamentally and fast. Power generation is becoming more and more decentralised making grid management increasingly complex. Electrical consumption continues to steadily rise all over the world. Meeting these challenges requires advanced automation and digital solutions covering the entire energy value chain.” IEEMA is the apex association of the Indian electrical equipment manufacturing industry.
In the recent years, automation systems for power plants have become more integrated and comprehensive with help of advances in hardware and software technology. In addition to providing a greater degree of plant automation, these advances have also provided the ability to more closely control all the processes of a power plant. This means that plant operations can be optimised against a variety of parameters to provide higher efficiency or greater flexibility depending upon the demands of the operator.
However, in Mr Chugh’s opinion, optimising processes in the power plant can also be a demanding task. “Especially if it is to be achieved without costly mechanical modifications such as major conversions to a steam generator and turbine,” he adds.
According to Mr Chugh, automation systems are enabling data analytical capabilities such as Predictive Analytics, Machine Learning, Artificial Intelligence etc. to increase system transparency and make informed decisions with help of actionable insights. For example, scenario planning, to get visibility into the impact of renewables on daily load profile of the power plant.
Automation enables process optimisation
Automation also provides control concepts form the basis for process optimisation solutions:
- Model-based, predictive feed forward structures
- Decoupling of highly intermeshed sub processes
- State space control
- Neuronal networks and fuzzy logic.
For example, formation of set points for main steam pressure, temperatures and firing rate, making maximum use of permitted thermal stresses for thick-walled components of boiler and turbine.
Use of robust state space controller for unit control and use of high pressure (HP) feed water heaters, adjustment of grinding pressure, etc. to accelerate unit dynamics.
This makes it possible to achieve extremely stable, reproducible and flexible operating behaviour with higher efficiency, better availability and lower emissions, opines Mr Chugh.
Additionally, sensors and communication devices are becoming more readily available and cost-effective, enabling asset connectivity. Citing an example, Mr Chugh said, a central data center can be created to manage entire fleet for integrated asset performance monitoring and advanced pattern recognition systems, that help in informed decision making, based on a robust and reliable analytical foundation integrated with deep domain knowledge.
Power generation is becoming more and more decentralised making grid management increasingly complex. Electrical consumption continues to steadily rise all over the world. Meeting these challenges requires advanced automation and digital solutions covering the entire energy value chain. RK Chugh, President Elect, IEEMA
Computer power & software are at the core
Computer power and software are at the core of new wave of automation systems. Without the advances in both computer hardware and communications, such systems could not be built. However, other factors are also important. Mr Chugh explains: “Advances in sensor and measurement technology have enabled many more power plant operating parameters to be measured and monitored than was possible in the past, providing a much more transparency about state of assets in real time. Modern distributed control systems (DCS) provide the ability to operate the operations of the plant more precisely than before. It is the integration of all these elements that have allowed power plant optimisation technology to evolve digitally to the level it has today.”
Automation & Power Plant Economics
In the competitive power generation market, power utilities are focused on optimising performance while minimising operational costs to deliver low-cost, high quality energy to their customers. However, experts believe, there needs to be a balance in the trade-offs between performance, operational costs and risks.
When it comes to fossil generation, performance optimisation is directly attributed to greater flexibility, higher efficiency, better availability and lower emissions.
Explaining how automation can change the overall economics of a power plant operation, Mr Chugh said, “Using the data from the DCS for advanced control concepts without major changes to mechanical equipment is one of the options to increase plants profitability.”
He further outlines how automation systems can drive economic benefits for power plants:
- High Flexibility: Enables plants to optimally react to changing power demands. The basis for simultaneously flexible and stable operation is enabled by advanced control concepts. For example: Coupled with Fast Start (start-up time reduced by 25 per cent), Fast Ramp Rate (over 2 per cent) and Frequency Control a 500 MW coal fired plant can generate additional value of approximately Rs 7 crore per annum.
- High Efficiency: Achieving optimised control is well proven strategy in power plants of all types across the world. For example, by reducing throttling losses and optimising the combustion air, the steam temperatures or the circulating water temperature, plants achieve higher performance. For example, with boiler combustion optimisation a 500 MW hard coal fired plant can generate additional value of around Rs 4 crore per annum.
- High Availability: Through less stress, with help of predictive feed-forward control and mobilisation of stored energy, advanced controls enable stable and precise load changes with minimum fuel overshoot. This minimises wear and tear on the plant components. With help of this outages are reduced and impacting the availability of the plant by more than 0.5 per cent.
- Low Emissions: Low emissions are achieved through an increase in efficiency which yields a simultaneous reduction in CO2 emissions. For example, for a 500 MW coal-fired plant, reduction of ash for disposal can be optimised by 20 per cent, average loss on ignition can be reduced from 5 per cent to 4 per cent, and overall efficiency can be increased by over 0.3 per cent.
The energy industry is currently undergoing transformation which brings with it vast opportunities and additional challenges forcing the industry to change. The challenges include incorporating renewables and distributed generation, regulatory and policy uncertainty, cost pressures etc. While these challenges aren’t new, technology
has evolved enough to allow us to address them with the use of automation and data-driven approaches that will propel the energy industry into the future, concludes Mr Chugh.
By Subhajit Roy, Group Editor