The smart grid will be at the heart of tomorrow’s connected world underlining the ‘Quality’ of life for each one of us, hence conscious planning and implementation of the smart grid with attention to good power quality environment is the only way forward.
Today, the electricity distribution industry is grappling with an unprecedented array of challenges, ranging from a supply-demand gap to rising costs. The distribution network today has become vulnerable and is increasingly governed by bi-directional power flows and fluctuating voltages determined by customer load & generation. Left with an ageing infrastructure, the conventional distribution network needs an upgrade and the smart grid phenomenon seems to be the way forward.
While the understanding of smart grid is different for different stakeholders, like five blind men deciphering an elephant in the room, however the fact is that we are in the midst of a revolution that can transform our conventional grid into an efficient and intelligent one. For most utilities, smart grid is about installing smart meters and establishing an outage management system, whereas for consumers and industries, the smarter grid would be of little value unless marked with highly reliable supply and resulting in optimized monthly electricity bills.
Effective implementation of the smart grid involves advanced distribution network automation integrating the power network with ICT technologies and electronic devices. Such automation demands adequate power quality to guarantee the necessary compatibility between all equipment connected to the smart grid. Power quality, therefore, is an important issue for the successful and efficient operation of existing as well as future grids. In addition, the use of sophisticated equipment (particularly DC) by consumers is also putting an additional responsibility on the network operator to maintain quality of supply as per the set standards.
Thus, this article attempts to discuss the importance of addressing the quality of supply requirements while implementing smart grid projects and leveraging these projects as an opportunity to improve and efficiently manage power quality.
How Quality of Supply (Qos) affects smart grid implementation
Effective realisation of smart grid requires advanced distribution network automation, which includes Substation automation, advanced metering infrastructure (AMI), outage management system, distribution management functions like voltage control or reactive power (VAR) control, harmonics detection and analysis, etc.
Such automation involves the use of power electronic devices and converters, which are highly sensitive to both voltage quality as well as harmonic distortion. The use of power electronic interfaced, often to achieve energy efficiency objectives, loads has considerably increased with the proliferation of personal computers, TV sets, adjustable speed motor drives for pumps or air conditioning appliances, etc. When these loads are connected to the grid, harmonics produced by these nonlinear loads are injected back into the supply systems. These currents interact adversely with a wide range of power system equipment thereby causing additional losses, overheating and overloading. Harmonics, one of the fastest growing PQ issues, are caused by the non-linearity of customer loads. Harmonics is a form of disturbance in electrical network, which influences and affects the operations of assets like transformers, feeders, etc. These harmonics also cause interference with telecommunication lines and errors in power metering, malfunction of data processing equipment, nuisance tripping of protective devices, etc. The smart grids equipment like communication devices, routers, relays, switches, capacitors, smart-meters, servers, sensors, etc. are very much vulnerable to harmonics and voltage, and hence maintaining the quality of supply plays an important role in implementation of smart grid.
Smart Grid initiatives in India and developed nations
Worldwide, national governments are encouraging smart grid initiatives as a cost effective way to modernise their power distribution infrastructure. India ranks third among the top ten countries in smart grid investments and has announced substantial smart meter rollout projects with a plan for more than 130 million smart meters by 2020 with an investment of $1billion. However, the existing policy and regulatory framework are typically designed to deal with the existing network. With the move towards the smart grid, these policies must evolve in order to encourage incentives for investments. Policy makers need to take some immediate action in certain critical areas like standards and regulations for its effective implementation. The Government of India (GoI) has appointed India Smart Grid Task Force (ISGTF) and India Smart Grid Forum (ISGF) with the prime objective of accelerating development of smart grid technologies in the Indian power sector by bringing together all the key stakeholders and enabling technologies.
Along with policies on smart grid, it is essential and important to focus on improvement in quality of supply. Government and various state regulatory bodies in India measures reliability supply indices such as SAIFI, SAIDI, CAIDI and monitor the interruptions on a regular basis, however there are no or only few occasions where Regulator has incentivised or penalised discoms for non-compliance on these parameters. Even reporting of such reliability indices are of doubtful integrity at times. Utilities that consider installing smart meters need to also focus more holistically on the overall quality of supply of smart grids than merely installing smart meters.
The table above shows the Smart Grid initiatives by some of the developed nations, thereby helping them improve quality of supply.
The new technology associated with smart grid offers the opportunity to improve the quality and reliability as experienced by the customers. This new energy infrastructure shall be greener, dynamic, flexible, reliable, secure, and resilient. However, an issue of voltage quality regulation, especially in integrated, multi-function and multi-communication platform like smart grid is considerably high. Improving power quality for implementation of smart grids will require new developments from all stakeholders involved. If appropriate and immediate attention is not given, it may lead to financial losses, equipment damage, etc. The smart grid will be at the heart of tomorrow’s connected world underlining the ‘Quality’ of life for each one of us, hence conscious planning and implementation of the smart grid with attention to good power quality environment is the only way forward. In fact, total power quality will enhance the benefits of the users as well as nation in a great way by reducing the loading of the Grid with unwanted PQ issues.
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5. Smart Grid Bulletin, April 2014
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Manas Kundu, APQI India (www.apqi.org), Coordinator
Kunjan Bagdia – APQI NSN Partner, pManifold Business Solutions