Smart Grid – A Prognostic Approach
Authored by: Mr. Niranjan Panda, Student NPTI MBA ( Power Management)
Albert Einstein had said,” We can’t solve problems using the kind of thinking that we used while creating them.” We have to be smarter while thinking of any solution to any problem.
In the history of electricity there exist no single defining moment. It is a result of 300 years of research and development. With the advent of electricity, not only was the workload on people drastically reduced but also it led to changes in the basic fabric of the society. In India, in a mere span of few decades electricity changed from a luxury to an utter necessity. This has vastly changed the way electricity is produced, distributed and used. The generation capacity has increased many folds and as of 30th October 2011 it stands at 182344.62 MW. Such large generating capacity needs equivalent evacuation and distribution infrastructure. Today’s grid is an engineering marvel. However, with all this advances the problems associated with having a integrated system in place have also surfaced. The strain on resources, fuel, sitting and building infrastructure are overwhelming. Electricity having been a part of life itself, any kind of disturbance in supply affects everyday life of all persons. So it is very important that electricity is available to all at reasonable cost, improved efficiency and proper asset utilization. There are solutions to these problems in the form of generation from renewable sources, flexible generation, distributed generation and energy storage systems. However, inclusion of all these in a already complex system throws up a tremendous challenge.
So it is now the time to update the way we get our electricity by starting to build a new smart grid that will save us money, protect our source from threat of blackouts and can deliver clean and alternate form of energy from every corner of our country. Smart Grid in the most simplistic point of view is the marriage of two infrastructure i.e. the electrical infrastructure and the information infrastructure. The availability of information regarding the functioning of the system will optimize the overall performance of the system. Few expected results of this marriage are as follows.
- The information about the consumption pattern will help in managing the peak via control of power consumption leading to demand optimization.
- The knowledge about the existing losses in the system and the points of pilferages will help reduce the overall losses in distribution system thereby optimizing delivery and giving higher profit margins.
- Proper monitoring of assets will lead to have a prognostic approach in proactive equipment maintenance which will reduce outages and asset optimizing.
- Through wide area protection and control the grid can be monitored for congestion and other anomalies which will lead to better network performance and reliability.
- And real time forecasting and smoothing of renewable generation sources will compensate for the production variability and distributed generation can be easily included in the network.
So smart grid in all can be divided in to three parts:
- Demand optimization – consumer participation.
- Advance Power Distribution.
- Advance Power Transmission.
Demand Optimization – Value to consumer
The first step in the implementation of smart grid is the metering infrastructure. And for this the work needs to be started right from the consumer premises by installation of smart meters. Smart meter is a digital device that records electricity consumption during a predefined time interval and provides a two way communication path from the consumer premises to the utility. They are also used in providing price schedules and demand response signals.
This helps is consumer participation in utility demand side management program and use of smart lighting and appliances. As the appliances can be given price signals so the energy consuming activities of these appliances can be delayed and so the load can be shifted for peak time to off pick time.
Advance Power Distribution
This part of smart grid implementation mainly deals with delivery optimization and asset optimization. Delivery optimization means the reduction of the losses that may occur either due to reactive power deficiencies or due to some physical faults or pilferages. For reactive power deficiency problem phasor measurement units are connected. They provide Integrated Volt/VAR Control (IVVC). They coordinate control of the substation tab-changer, feeder voltage regulators and capacitor banks to maintain proper VAR and voltage profile. This leads to reduction in distribution and system losses.
The SCADA and GIS have very important roles. The main role of SCADA is to collect data and automatic fault detection and correction. GIS act as a human interface so as to identify the fault location properly as it gives a pictorial replication of the system. When fault occurs the smart meter gives a signal of power outage at the premises. Through load flow analysis best adjacent circuit to pick up the load is identified. Then crew investigates repairs and restores the system back to original condition.
Having achieved deliver optimization, the optimal utilization of assets must be carried out. It helps in reducing capital expenditure, increasing asset life and reduces the chance of catastrophic failure. Online monitoring and diagnosis allows the utility to have condition based monitoring and maintenance which not only reduces cost of inspection and maintenance but also allows early detection of faults which can thwart any chances of blackout and thus any loss in revenue.
Advance Power Transmission
Advance power Transmission primarily aim at improving the reliability and efficiency of transmission system while implementing means of mitigating transmission congestion. There are two main part of it Wide Area Measurement and Control (WAMC) and inclusion of distributed generation facilities in the network. WAMC mainly increases the situational awareness of the system operator with immediate detection and representation of the MW/MVAR oscillation in the system. This can fasten up decision making process such as the under voltage load shedding decision which proactively eliminates the probability of black out. WAMC primarily measures, detects and help system operator to take appropriate action.
When power is being generated through conventional ways then due to economies of scales bigger plants are preferred but under such scenario the evacuation of power can be a issue. This often leads to transmission congestion which puts unnecessary stress on the system. Such a situation can be avoided and that too continuing to optimally satisfying the demands of the load. This is achieved through the inclusion of distributed generation. These are normally non-conventional source of energy which are not so predictable, that is why their inclusion is an issue. As they are often not equipped with a load-frequency control, they will free ride on the efforts of the transmission grid operator or the regulatory body to maintain system frequency. However, with real time forecasting and smoothing they can be included in the system more easily.
In India, the power sector is going through a tough time as the revenue generating link of the value chain that constitute the power sector is under the burden of tremendous losses. The losses of the discoms have reached to level of 70000 Crores and despite many efforts the AT&C losses continue to hover around 30%. The implementation of Smart Grid in India will lead to complete check of the existing pilferages. The transparency that will come in with it will help reduce losses and thus improve financial condition of the discoms. As the existing problems couldn’t be solve by a diagnostic way of thinking lets try the prognostic manner once!