The smart grid concept is introduced to accelerate the operational efficiency and enhance the reliability and sustainability of power supply by operating in self-control mode to find and resolve the problems developed in time. In smart grid, the use of digital technology facilitates the grid with an enhanced data transportation facility using smart sensors known as smart meters. Using these smart meters, various operational functionalities of smart grid can be enhanced, such as generation scheduling, real-time pricing, load management, power quality enhancement, security analysis and enhancement of the system, fault prediction, frequency and voltage monitoring, load forecasting, etc. From the bulk data generated in a smart grid architecture, precise load can be predicted before time to support the energy market. This supports the grid operation to maintain the balance between demand and generation, thus preventing system imbalance and power outages. This study presents a detailed review on load forecasting category, calculation of performance indicators, the data analyzing process for load forecasting, load forecasting using conventional meter information, and the technology used to conduct the task and its challenges. Next, the importance of smart meter-based load forecasting is discussed along with the available approaches. Additionally, the merits of load forecasting conducted using a smart meter over a conventional meter are articulated in this paper.

A differential protection scheme, based on real time analysis of a time-frequency based technique, is proposed for transmission line with mid-point connected static synchronous compensator (STATCOM). The first intrinsic mode function obtained from the decomposition of current signals from both ends of the transmission system, processed through Ensemble Empirical Mode Decomposition technique, is used to estimate the Discrete Teager Energy (DTE) through online Hilbert-Huang transformation. The differential DTE from both ends of the line is used to detect the exact faulty phase. For analysis, a mid-point STATCOM compensated transmission line model is considered and simulated using EMTDC/PSCAD. Test cases, such as high fault resistance, fault inception angle, reverse power flow, current transformer saturation and variation in source impedance are generated for different operating modes of the STATCOM. The method is also tested for cross-country fault in double circuit transmission system. Comparative assessment reports with other conventional approaches verify the reliability, speed and feasibility of the proposed method.

In this paper, transient response of the microgrid caused due to unintended switching events and faults have been investigated in distributed generation (DG) system. The proposed technique is based on two new criteria; i) transient index value (TIV) and ii) positive sequence superimposed current angle at PCC. The proposed method utilizes three phase voltage signals at DG end to compute the TIV. The performance of the proposed integrated approach has been evaluated on a sample test system and a practical distribution network consisting of combined heat and power plant, wind turbine generators, and photovoltaic system. The simulation results demonstrate that the proposed technique exhibits high reliability and leads to faster detection of islanding condition as compared to the existing passive islanding detection methods not only for zero active and reactive power mismatch conditions, but also for transient events caused due to nonlinear loads.

In this paper, a directional relaying algorithm for the protection of double circuit line with series capacitor is presented. The method uses four classifiers based on positive and negative sequence components which are combined with a voting technique to derive the direction of fault. The technique is evaluated using data simulated with electromagnetic transients including DC/power system computer added design (EMTDC/PSCAD) for a series compensated double circuit line. Results for voltage inversion, current inversion, high resistance far end fault, single pole tripping and cross country fault are presented. The proposed technique is found to be accurate.

Majority of the high impedance faults (HIFs) occur through the ground and, due to the nonlinear variation in the fault signal, false detection rate is high. HIFs are accompanied with high frequency components and signal decomposition techniques are best suited to detect such faults. In an active distribution system, detection of HIF and its discrimination from capacitor switching, nonlinear switching and transformer energization is a challenging task. Also, the presence of noise in the signal complicates the detection task. A major gap in the detection process exists in the treatment of the negative impact of inverter based distributed generator. Taking the configurational and operational constraints into account, an Intrinsic Time Decomposition and Teager Kaiser Energy Operator (TKEO) based HIF detection approach is developed for distribution system. The first intrinsic mode function that contains the highest frequency component is extracted and applied to estimate the TKEO. The energy operator always surpasses the threshold range during HIF. The main advantages of this technique are that it has high immunity to noise, system unbalances and presence of harmonics and it does not rely on high current magnitude to detect the fault. Performance of the method is tested on several test cases.

This study presents a transmission line fault classification algorithm using integrated moving sum (IMSUM) technique. The method is based on current signal only. In this method, the decision of moving sum approach‐based fault detection unit is used in integration with the proposed method to obtain accurate fault class. Rules are set for all ten types of fault. Considering half cycle computed data from the instant of fault inception classification is possible. High‐resistance far‐end fault, close‐in fault, fault at different inception angle and fault considering variable prefault loading conditions can be easily classified using IMSUM technique. Severe current transformer saturation and weak infeed conditions are also discussed. The method can also be applied to a series compensated line. Any variation in fault and system condition will not alter the decision period of IMSUM technique which is an exceptional attribute for a protective function.