Digitalisation is playing a key role in the upgradation of conventional power plants, which will help meet the changing market requirements. A digital power plant offers efficient and cost-effective power generation, reduces maintenance expenses and enables quick load adjustment.
Several factors are driving digitalisation in the power generation industry. One of the key factors is large-scale renewable integration. This is characterised by a certain degree of variability and uncertainty as the availability of renewable sources depends on weather conditions, resulting in ducking of the load curve. This may also lower the plant load factor of TPPs. With the increasing renewable energy penetration, TPPs need to frequently ramp up and ramp down power generation. This leads to poor heat rate, high auxiliary consumption, increased forced outages, high operations and maintenance (O&M) requirement, and reduced equipment lifetime. The digitalisation of boilers, turbines and generators (BTGs) can help maintain operational efficiency under flexible power plant operations. Further, a fleet-wide digitalisation of O&M practices enables TPPs to meet these dynamic requirements. Another driver of digitalisation in the BTG space is the increasing cost of compliance with environmental norms. This increases operational complexity and puts a strain on operating margins. Digital solutions can support and facilitate this transition through asset optimisation strategies.
Digitalisation also aids enterprise management through real-time network monitoring and reporting. With customised dashboards, business intelligence tools, digital work processes and blockchain-enabled transactions, gencos can move towards analytics and data-driven decision-making.
Digital solutions for power plants
The digitalisation of BTG equipment entails the deployment of sensors, actuators, digital controllers and supervisory computers. Through feedback control loops, plant processes and performance can be monitored and appropriate control actions can be taken in case of system disturbances such as changes in coal quality and load demand. Machine learning and artificial intelligence (AI) can help derive meaningful insights from operational data and take corrective measures to maintain plant performance, reduce unplanned outages and downtime, and extend the operational lifetime of assets.
Remote monitoring and diagnostic systems can be deployed for monitoring TPP assets. These systems have an interactive display for improved operations and an advanced pattern recognition feature, which identifies anomalies in plant operations. Another digital solution for power plants is the digital twin. It is a digital replica of a plant asset. The digital twin uses algorithms and models of AI and machine learning to predict the future performance of the plant. It leverages big data for driving efficiency and generation. Another cost-effective digital solution used in the power generation segment is 3D printing, which helps in maintaining spare readiness. This minimises the lead time for spare part manufacturing. Apart from this, the blade vibration monitoring system (BVMS) prevents last-stage blade failure in turbines, which occurs as a result of electrical corrosion, corrosion fatigue, stress corrosion, water corrosion and equipment fatigue caused by material quality issues, load variation, etc. BVMS tracks the performance of turbines and helps in improving plant availability and reducing unplanned shutdowns. The acoustic steam leakage detection system helps track steam leakages in boilers with the use of sensors on a sonic tube. If the sound of the steam leak exceeds the preset limit, an alarm is set off and the registered contacts are alerted.
On the flexibilisation front, digitalisation is essential for bringing down the levellised cost of flexible power through forecasting and automatic generation control. Condensate throttling is a widely used digital solution to maintain plant performance in a quick response load change scenario. When the condensate water control valves close, the demand for low pressure heaters reduces and extraction steam has to pass through the last turbine stages, thus increasing the turbine power output. Some of the other digital solutions for flexible power plant operations are boiler auto-tune; advanced monitoring systems; online predictive tools for predicting failures, providing maintenance advisory and predicting cycling costs; lifetime assessment tools; and coal analysers.
The real-time tracking of power plant operations, coupled with flexibilisation, helps in maintaining the competitiveness of conventional power plants. It not only helps in improving the operational performance of TPPs at minimum expenditure, but also enables practical upgrades. In order to fully leverage the benefits of digitalisation, optimal and efficient use of plant performance data is important in order to predict future scenarios. This will help in minimising the unexpected downtime. A downside risk associated with digitalisation is that it makes TPPs more vulnerable to cybersecurity attacks. Thus, utilities need to proactively manage the risks associated with data and physical assets, and adopt best practices to keep systems secure and up to date. For the successful implementation of digital solutions at power plants, it is also essential to undertake change management, provide workforce training and conduct organisational reviews.