V. S. K. Murthy Balijepalli’s research while affiliated with Indian Institute of Technology Bombay and other places

An effective demand response (DR) model framework for DR management systems in a residential premise is proposed. The proposed model consists of dynamic price signals from load serving entity (LSE), benefit function, and loss of consumer comfort. The conventional approaches generally consider these factors as independent in their formulation. Since these factors have functional relationship, the proposed model points to a holistic approach to capture the relationship. The scheduling model can be integrated with the home energy scheduler coupled to the smart meter, which facilitates the flow of dynamic price and energy consumption information to and from the household premise. The objective is to maximize net consumer surplus, which is formulated as a function of all aforementioned factors. A method for developing a practical and dynamic consumer benefit model for matured DR programs is proposed in this paper. For the purpose of showing the effectiveness of dynamic benefit function, a set of analytically formulated benefit functions is also considered. The suitability of the dynamic benefit function, as compared with other alternatives, is illustrated with an example. This paper also reports the dynamic price design from the view point of LSE, in order to cover the risks of wholesale price volatility.

Future grid evolutions promise to promote the interoperability in the consumer domain. CIM (mainly IEC61970 and IEC61968) is an established standard in the industry to enable the interoperable data exchanges at the upstream levels like generation, transmission and distribution, while the Green Button standards (OpenADE, NAESB ESPI, NIST SGIP-PAP 20, PAP10) are the emerging smart grid standards to standardize the information on energy usage, interfaces at the downstream end-consumer level. This paper presents the various modeling issues, and techniques to move toward integrating these standards to enable the interoperable services at the consumer levels. The challenging task is to identify the options to promote the interoperability between the end-consumer and upstream levels for future grid evolutions. This paper begins to address this issue by identifying the requirements like integrating the external services data from the end-consumer oriented third party tools to EMS/DMS, hierarchical tagging of consumers, combined semantics for third party applications, inter-utility migration of consumers/prosumers, and dynamic consumer/prosumer open access interactions. However, this involves extensions and mappings between the existing CIM, and the green button standards. Without affecting much the base packages, it should be either incorporated in the CIM or Green Button standards at the domain modeling as a separate package. A set of new classes and attributes to the existing CIM and the corresponding XML tags for Green Button standards to realize the integration is proposed. The authors' contributions also strengthen the arguments for creating a separate green button profile for the existing upstream standards.

Establishment of the interoperable applications at the electricity generation, transmission, distribution, and market domains is almost accomplished through various standardization activities. At this juncture, advent of the smart grids has opened the new avenues like the consumer domain for the standardization activities, and down the time-line the future grid may evolve for the consumer oriented interoperable systems. This paper attempts to presents an overview of Smart Grid pilots in India along with further scope of standardization. A description of the consumer domain standards is presented to identify the gaps in moving towards realizing the smarter grids. Standardization of the energy usage information is a foundation block to promote such systems. Recently released Green Button standards cater to this purpose. In this context, paper recommends the standardization of energy usage information provided to the consumers in the ongoing smart grid pilots and presented the implementation experiences of these standards at MSEDCL, Maharashtra. An introduction to “GREEN BUTTON — CIM Tool (GamBIT)”, first of its kind tool available in public domain to educate entities/stakeholders of Electric Power Systems in India on power system and smart grid standards.

For the assessment of voltage instability which comprises the detection of voltage instability and identification of critical buses, two indices namely, system wide Qtax, and bus-specific qtax, are proposed. The Qtax, based on the sensitivity of the reactive power injections to the loading in the system provides early detection of impending voltage instability. The computed qtax indices identify the critcal buses among the load buses in the system. The identified critical buses provided optimal lacations for the corrective control actions for averting voltage instability. Additionally, for voltage stability monitoring, determining the poing of exhaustion of the reactive reserves in system is also crucial. This is addressed by proposed Q-Monitoring Index (QMI), which is the ratio of the reactive component of the source current to the sink current that flows through the adjacent transmission line. These proposed indices together can provide early indication to impending voltage instability. This has been illustrated on IEEE-39 bus system. The reactive support on identified critical buses results in maximum increase in the loadability of the system.

This technical article presents the concepts for improving the electricity price forecasting which were patented (application no. IN236/MUM/2011). A novel system and method for electricity price forecasting are also disclosed to set the context for explaining the technicalities involved in the invention. The invention relates to forecasting, and particularly to price forecasting by employing error correction techniques external to the algorithm chosen to solve the forecasting problem. Existing mechanisms do not offer effective error correction mechanisms external to the forecasting engine. The proposed technique uses the stochastic formulations and golden search methods to improve the final forecast. The method initially employs a forecasting module which consists of SVM, robust regressions, and neural network based mechanisms to determine the initial forecasts. In case there is an error, it determines if the error is within the permissible values through various probability checks. Further, if the error is outside the permissible values then a correction factor is applied to the computed values and prediction is updated. The correction factor is determined using the golden search technique. The framework for the proposed approach has been tested on the Indian and Australian electricity market data to prove its efficacy.

Common Information Model (CIM) has been identified as the information exchange platform for Distribution Management. Distribution utilities in India perform multiple functions of varied nature to meet equivalently myriad challenges, in many ways unique to them. This paper discusses two of them, namely, load shedding & restoration and power purchase with scheduling. Significance of load shedding & restoration activity is apparent since India is a power deficient state. Power purchase with scheduling activity gains prominence since it involves all the three modes of fixing rate of energy namely pre-fixed, negotiable and price discovery in market. Modeling of these two use cases of Indian distribution system in CIM is presented in this paper. The essential extensions required can be derived from IEC 61970, IEC 61968 and IEC 62325. The new extensions are described. These models can be used as guideline for building CIM based software applications for them.

Demand response (DR) has an important role to play in the electricity market for maintaining the balance between supply and demand by introducing load flexibility instead of only adjusting generation levels, at almost all operational time scales. There are many players in the market who benefit from DR, like the TSO, DSOs, retailers and end-customers themselves. The recent advent of smart grid technologies advanced the integration of DR by providing the needed information and communication infrastructure to the existing grid. Available literature on DR talks about the concept and definitions of DR, possible DR models for various region-specific market structures along with few DR implementation experiences in a system with ever increasing levels of loads along with evolution of innovative technologies like renewables, micro-grids, PEVs, etc. In this paper, the available literature on DR is categorized into general concept papers and papers on DR models applicable to the wholesale or retail markets, and are presented in a precise manner.