Smart Distribution Grids: Beyond AMI
Past few years have been awakening for the industry in terms of realization of aging infrastructure and need for innovation with advancement in technology both on Information Technology as well as Digital Electronics for equipments and Measurement & Sensing. Smart Grid in a sense is revolutionizing the industry and unlike any other revolution here the challenge is that we do not know where we will land when the Smart Grids are reality. Initial years of the smart grid investments, have been focused (and still focused) on the Smart Meter deployments and AMI communication. The need is to realize the real benefits of the AMI deployments. Is the investment worth for the purpose of providing transparency in to the electricity bills to the customers (at least that's what most of the AMI implementations and Smart Grid solutions by IT majors claim)? The focus now needs to shift beyond AMI from the actual Transmission & Distribution Grid's perspective. The real benefit or return on investments on AMI infrastructure will be realized when the Distribution Grids become smarter. The key goals (there are many more) of Smart Grids are as follows:
- Customer Enablement (Energy Bill transparency, direct customer participation etc.)
These objectives are said to be achieved by having two way communications between the distribution control center and the customer premises. All is achievable with the latest technology. The effectiveness and acceptance by the end customers may be questionable. But as said earlier it's a revolution and with any revolution there are apprehensions as it promises big changes the way (in this case) one looks at electrical transmission & distribution systems at present. For the some it's a new Smart Meter and smart thermostats and for some roof-top solar generation, so how it's going to benefit them?
Unless the distribution control center becomes smart enough to show the benefit of the smart grids, the benefits from investment as well as customer perspective cannot be realized or proved.
For utilities, making the best use of the smart grid involves significant planning, preparation and focus. Utilities have started to invest in the new technologies and ideas, but proper planning is required so that they can be prepared to leverage new enabling technologies, standards-based interoperability, cutting edge communication technologies and intelligent field equipments to deliver increased reliability, operational efficiency & customer satisfaction.
The enablers are going to be the smarter distribution grids. This will be possible by implementing real-time monitoring and remote control of subsystems like, substations, intelligent devices, distribution lines, capacitor banks, feeder switches, fault analyzers and other physical facilities. Smart Distribution Operations will be realized with smarter distribution automation systems which enable two-way communication with these subsystems and provide framework for self-healing grids by facilitating ways to identify and isolate faults, and automate the intelligence to restore service.
It's not that Distribution Operation Centers are not presently using distribution automation to achieve the same goals of reliability and operational efficiency and some examples of such applications are as follows:
- Substation SCADA
But if we look at typical distribution operation center these functions are done in isolation, though there is co-ordination (mostly manual) for the successful grid operations. With new technologies and solutions available there is a need to change the Distribution Operations in such a way that the goal of smart distribution grid can be achieved by having features such as,
- A unified customer to network connectivity model to maximize the grid asset utilization by optimized system loading, situational awareness and system planning
- Single-window view for all distribution grid with localized automation & control
To achieve the aforementioned objective and goals utilities have to plan and prepared to face many technical and economic challenges. There won't be a single application, product or solution called "Smart Distribution Grid", but it will be an ecosystem of heterogeneous applications working in tandem to make the distribution operation smart. Even though from operational objective perspective all the utilities are same but applicability of distribution applications within a distribution grid depends on various factors such as % distribution of customers by customer segment, geographical location, present state of the system, operational goals (i.e. reliability v/s efficiency or reliability & efficiency) e.g. a substation catering to customers with large number of Industrial customer will get benefitted by implementation of Volt/VAR control but similar may not be true in the distribution area where number of residential customers is more prevailing.
Another related challenge is that not a single vendor can cater to all the needs of Smart Distribution Grids as it involves not only T&D system applications but also new age IT solutions, field equipments and communications infrastructures. Hence Integration & Data Management will become a big challenge between these applications and equipments.
Benefits of Smart Distribution Grids are generally categorized as follows:
- Customer Benefits
Aforementioned benefits though categorized separately, are dependent on each other and influence each other. In the simplistic term, if the objective function of one DA application is to reduce the cost of operation for utility, may in turn reduce the energy cost to the customer hence provide socio-economic benefits.
Clearly, there is a need of smart distribution operations which justify the investment in AMI i.e. Smart Meters, 2 Way Fixed Network Communication Systems. These investments are perceived as a major move toward increased grid stability and reduction in outages or blackouts which is the prime goal of the Smart Grid.
Following business drivers need to be considered for the investments in the Smart Distribution grids beyond AMI or to use AMI:
- DER Integration to reduce the dependency on the transmission grids and large power plants to meet the local demand.
Hence, the focus now needs to shift beyond AMI in the context of Smart Grid and look in to the Smarter Distribution Operations to realize the benefits of investments in the AMI and grid infrastructure upgrades.