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Electrical energy theft is a major concern for power distribution companies as it results in an increase in non-technical loss. This overloads the distribution network and also forces power Distribution Company to increase tariff on legal consumers to meet these losses. Direct hooking on distribution overhead line or tapping’s from underground cables remains perpetual issue which should be stringently annihilated. The objective of this research work is to design and develop online electrical energy theft detection and prevention scheme (E2TDPS) with the available infrastructure in field. Proposed E2TDPS collects online data from the digital energy meters connected in the premises of legal consumers and at distribution transformer. From this data, proposed algorithm determines the voltage regulation and non-technical loss in the distribution network. It identifies the pilferage section and estimates the power stolen by illegal consumers. It can send the date, time and locations of power theft on the cellular phone of utility engineers. Thereby, the utilities can arrange raids at theft locations to catch the miscreant. The prototype is tested in the laboratory, and the results demonstrate that the proposed E2TDPS works satisfactorily under diverse operating conditions.

In this modern era, the power system is stigmatized by a conglomeration of ultra-high voltage AC and DC, multi-terminal DC, and extra-high voltage AC transmission networks. It consists of a large distribution network beyond the country along with traditional generation having Ultra Mega Power Plants (UMPP) and growing ingress of Renewable Energy Sources (RES). The System Integrity and Protection Schemes (SIPS) play a crucial role in preserving a secure and reliable grid and facilitate efficient grid control during severe power system contingencies. In this paper, the operational experiences of three important SIPS in India are presented. Based on a thorough analysis, the drawbacks of these SIPS are identified and an algorithm is proposed to overcome the drawbacks using synchrophasor technology. The performance and capability of the proposed algorithm are evaluated by simulation studies on the 39-bus New England system embedded with HVDC link in MATLAB. Simulation results consummated confirm the effectiveness of the scheme in preserving system integrity. Results are validated using Electrical Transient Analyzer Program (ETAP), which is a very powerful design and analysis tool and has an extremely user-friendly interface.

Novel grid code allows heavy penetration of wind electric power into the grid which leads to new challenges of power quality like harmonic pollution in variable speed wind turbines with asynchronous generator. The article provides an analysis of the existing methods for identifying wind farm contribution to harmonic distortion at a point of common coupling. The considered methods do not allow correct and fair determining of the source of harmonic distortions, or they have limited application and difficulties in implementation. The paper proposes new methods for determining the source of high harmonics. A wind farm model is prepared using MATLAB software, and harmonic analysis is described for different wind velocities. Causes of harmonics generation in wind farm and harmonics pollution mitigation by DSTATCOM modeling with unbalanced grid disturbance of grid side wind mill inverter have been mentioned. The custom power device (CPD) is developed based on nature of harmonics and interface with grid-connected wind farm to enhance the power quality of wind farm. Results obtained from MATLAB-based harmonic analyses are compared with practical case study results that have been presented as per IEEE standard 519-1992, IEC 61000-2-2 and EN 50160 standard harmonic limits. Identified indirect current control scheme of custom power device can be supported to uncertainty analysis.

The dc microgrid consists of renewable energy sources, energy storage system, and loads. The power output of these RESs is intermittent in nature. This raises the problem of power sharing among the sources and bus voltage regulation. This article proposes a new fuzzy logic based control scheme to mitigate power sharing mismatch during the variation in available power of RESs. It exploits the nonlinear mapping between sources power sharing with variation in available power. The novel fuzzy logic controller improves the system bus voltage regulation under different operating conditions. It is simple in design and does not need knowledge about a complex mathematical model of the overall system. The experimental results are presented which shows the superiority of the proposed control under different operating conditions over the conventional control.

This article presents an integrated control scheme to improve power sharing for power management and voltage regulation in DC microgrids. The proposed scheme considers the available power and the stochastic nature of sources to achieve adequate power sharing among them. Therefore, it achieves effective utilization of each source. In addition, the effective use of energy storage systems (ESSs) is also achieved by reducing their charging/discharging cycles. The proposed control scheme improves voltage regulation under various operating conditions. It enhances the stability of microgrids and improves their dynamic response. The proposed control scheme is adaptive to changes in the source or load. It operates without historical/previous data, which reduces the computational burden. The proposed control scheme is experimentally validated under diverse operating conditions.

Electricity theft is a notable aspect of power distribution utilities due to advance in the non-technical loss. It results imbalance between power supply and demand. It consequence overload of the distribution network and extraneous tariff invoke on legally connected consumers. The advance metering infrastructure is useful for an energy audit of every distribution transformer due to a communication facility. However, direct hooking on distribution overhead line or tapping from underground cables remains an interminable issue which has to be rigorously decimated. The objective of this study is to present real-time electricity theft detection and prevention scheme (ETDPS) with the available infrastructure in the field. The proposed ETDPS is based on programmable logic control; it identifies the pilferage locations and estimates the power stolen by illegal consumers. The prototype is tested in the laboratory and the results demonstrate that the ETDPS works satisfactorily under diversified operating conditions. The proposed scheme is implemented as a part of their Smart City Pilot Project by Maharashtra State Electricity Distribution Company Limited, Nagpur (India) and the performance demonstrates its feasibility.

Measurement current transformers (MCTs) are an important component in the measurement of electric power. In this era of deregulation, every power distribution company strives for maximum revenue. It could be possible if the errors present in MCTs are reduced. Maharashtra State Electricity Distribution Company (MSEDCL) is one of the power distribution utility in India interested to resolve its problems regarding MCT error compensation. In this article, the MCT error compensation problem was tackled for various operating conditions. These conditions include metrological properties of core, transformation ratio, burden, remanent flux and nature and quantum of load connected on the primary side of MCT. The MCT secondary side waveform is analyzed for various operating conditions, and from these data, the artificial neural network (ANN) is trained. Implementation of the compensation system and data acquisition is done using dSPACE 1104 software. Experimentation is performed in MSEDCL laboratory, and test results demonstrate the effectiveness of the proposed system.

—Industrial Energy Measurement System (IEMS) used for measurement of electrical energy consumed by high-tension industrial consumers. It consists of three current transformers (CTs) and thr...

A modular structured 12-kW resonant converter with effective zero voltage switching (ZVS) is proposed to integrate renewable energy lower voltage source to the microgrid. In this study, duty cycle control is adopted until ZVS fails and thereafter, sequential and parallel adjustment of duty cycle and the switching frequency is proposed for effective output voltage regulation. The proposed control logic ensures ZVS and output voltage regulation over wide load range even at very light loads compared to conventional control methods. Further, it maintains very high system efficiency with narrow range of frequency operation. Hence, it is easy to implement using a conventional digital controller. To minimise ripple current, each of the four converters is provided with 90 ° phase delayed gate pulses under the proposed control scheme. This study presents an optimal design of the tank circuit elements assimilating high permeable powder cores to reduce magnetic loss and operation with IGBT switches at an optimum point to reduce conduction loss for enhanced system efficiency. A 12-kW, 400–1600 V developed prototype is tested and experimental results are discussed.

Electricity theft is a major concern for power distribution utilities. The increase in non-technical losses give rise to imbalance between electricity supply and demand resulting into overloading of existing distribution network, reduction in reliability and stability of supply and additional tariff posed on genuine consumers. Although, the smart metering systems has resolved meter related power theft problems, however, direct tapping on distribution line remains perpetual issue which should be stringently annihilated. Thus, this paper presents real-time electricity theft detection using energy consumption data of all legal consumers and outgoing distribution transformer energy meter data. In order to prevent the hook-line activity, a fuzzy inference based scheme is implemented in LabVIEW to operate electricity theft prevention system (ETPS). The ETPS develops unsuitable voltage across illegal consumer and hinders normal operation of their appliances. The consumer care unit (CCU) interlocked with ETPS maintains normal supply voltage at legal consumers end. The suitability, flexibility in operation and effectiveness of the proposed ETPS and CCU based theft prevention scheme is experimentally and practically demonstrated as case study under various voltage regulation and energy loss scenarios.

This paper proposes a new control algorithm for effective power management in the dc microgrid with renewable energy sources (RES) and energy storage system (ESS). This scheme overcomes the average power sharing and bus voltage regulation problems with maximum utilization of source power. In the source, the additional power available beyond its average rated value is treated as virtual generation. The new references are generated considering virtual generation. The novelty of the proposed algorithm is to bring the virtual generation effectively in operation. The virtual generation of the individual source is based on available power source. The proposed algorithm reduces the charging/discharging cycles of ESS and, hence, enhances the life span of ESS. It reduces the stress on interfaced converters, regulates the system bus voltage, reduces power fluctuations on the sources, and enhances stability. The proposed control algorithm is verified in MATLAB simulation and in real-time simulator.

The power transmission system, in this age, is characterized by ultra- and extra-high voltage AC, and multi-terminal high voltage DC networks. It has a wide-area power network across the nation. It incorporates conventional and ultra-mega-power plants (UMPPs). It also has a submission of increasing penetration due to Renewable Energy Sources (RES). A crucial role is delivered by the system integrity and protection schemes (SIPS) in sustaining guaranteed and safe grid operation. A SIPS also assists efficient grid management during serious power system emergencies. In this article, thorough investigation of the performable capabilities of three influential SIPS in India is made. The shortcomings in ongoing SIPSs got revealed. A proposed methodology eliminates these obstacles. Apperception and vitality of the recommended technique get decided by simulation exercise on an IEEE 10 generators 39-bus test system ingrained with HVDC link in MATLAB. Simulation outcomes accomplished the credibility of the method in defending system integrity. Electrical Transient Analyzer Program (ETAP) is used for the validation of MATLAB results. ETAP has an organizing/investigation mechanism and it is a remarkably convenient interface.

An optimized resonant converter with zero-voltage switching over an extensive range of loading is proposed to integrate renewable energy sources to an onboard charger. In conventional resonant circuit, high-frequency transformer (HF) parasitic components are used as tank circuit, this degrades the performance due to non-optimal magnetic components. Here, the HF transformer is fabricated with optimized resonant tank circuit shunt branch inductance ( $L_p$ ) as magnetizing inductance, hence eliminating the need for shunt branch inductance. The proposed resonant converter circuit design is optimized for minimum kilovoltampere rating and better voltage regulation with both duty cycle and frequency control (mixed control method). Furthermore, the performance of the converter at a very light load is improved using the proposed control method. Incorporating a low- $R_{\text{DS}}(\text{ON})$ silicon carbide mosfet and softly turning off the switches for a wide load variation minimizes conduction and switching losses and improves efficiency. Using powder core for the design of the tank circuit reduces magnetic losses. A 3-kW prototype of the converter is built to verify the performance from no load to full load. The highest efficiency of the proposed converter is 98.6%, attained at 50% full load.

Current transformers (CTs) are extensively used for the measurement of electrical energy, and hence they play a crucial role in the revenue generation for power distribution utilities. The novelty of this paper is that it presents artificial neural network (ANN) application for the ratio and phase angle error corrections of CTs in the presence of harmonic distortions. In this paper, the behaviors of silicon iron alloy and nanocrystalline alloy CTs are examined by the means of a number of experimental tests under the sinusoidal and distorted waveform conditions. The relation between the nature of CTs secondary current waveforms (CTSwf) with their metrological properties, connected burdens, and nature of load currents (linear or nonlinear) is established. The training data are obtained by the nature of CTSwf in terms of amplitude errors, time shifts, and deviations caused by different harmonic contents between input and output quantities. The ANN is trained for various operating conditions. The implementation of the error correction system and data acquisition is done using dSPACE 1104 software. The experimental results illustrate that the proposed technique can be used for error compensation in case of sinusoidal and the distorted waveform composed of fundamental and many harmonics.

Power Quality (PQ) is a major factor for utilities to consider when meeting customer demands. Poor PQ can damage sensitive equipment and lead to costly repairs, resulting in lost time, corrupt data, and lower productivity. It also increases losses, raises electricity bills, and reduces the life expectancy of electrical equipment. In this article, a fuzzy system is used to determine PQ for various operating conditions and study its effect on the performance of distribution transformers (DTs). Experiments are performed on a three-phase, 15-kVA, 400/400-V DT. The input supply voltage to the DT is intentionally disturbed by means of a motor-alternator-variacs-triacs assembly to obtain different PQ conditions. A fuzzy system is developed with offline and online approaches. This system has five measurable inputs-supply voltage, load current, frequency, harmonics distortion, and winding temperature-and one output variable, PQ. Offline and online experimental results are compared. Results show that the efficiency of a DT decreases with PQ degradation, and the proposed fuzzy system is able to make accurate diagnoses.

Measurement current transformers (CTs) are extensively used for measurement of energy by power distribution utilities. In this paper, current transformer error compensation unit (CTECU) is developed which is specially intended for providing compensation to all types of measurement CTs. The proposed CTECU is based on determination and application of correction coefficients, which are computed by the ratio and phase angle errors data. Analytical foundation is effectively expressed along with the development of CT error compensation algorithm. CTECU is implemented online in laboratory on 1.0 class and 0.5 class of CTs. The experimental performance is found satisfactory under various operating conditions. The novelty of the proposed algorithm is that it is possible to make conversion of CTs from one class to another class.

This article describes the development of an error compensation algorithm for a measurement current transformer (CT). The flux-magnetising current loops are derived in the proposed algorithm to minimise the number of required loops for computation. At every sampling interval, the exciting current is obtained from these loops and then it is added to the measured secondary current to gain the corrected primary current. The performance is tested using MATLAB program and later, the same code is executed in LabVIEW environment. Performance analysis indicates that the proposed algorithm improved the accuracy of the measurement CT notably even with minimum loops. The experimental test results demonstrate that the compensator is capable to correct the accuracy of the measurement CT in remarkable manner.

Nowadays, DC microgrid is getting much more attention due to its simplicity and cost-effective behavior. On the other hand, DC microgrid is facing protection issues due to lack of effective protection schemes. Therefore, protection has become a more crucial aspect in DC microgrid. In DC Microgrid, there are two types of fault, one is low impedance fault (LIF) and the latter one is high impedance fault (HIF). In this article, a high impedance fault has detected by using the Least Square estimation technique. And also, the fault location and fault resistance have been estimated. For the fault analysis, a five bus ring-type DC microgrid has been considered, and it has simulated using MATLAB/Simulink environment. The novelty of the proposed protection scheme is that it does not require any communication link to detect the fault.

AC protection schemes are well understood and mature. On the other hand in the DC system, the development of protection schemes is the main challenge for the researcher because of additional power electronic devices. Some protection schemes are developed on the principle of the rate of change of current but it may mall operate for the noisy system. In this article, a protection scheme is developed based on the numerical computational method(Trapezoidal method) to fast detection of the fault and also to avoid the effect of the noise. The proposed protection scheme is validated on the ring type DC microgrid for different fault conditions and tested through MATLAB/Simulink Simulator.

In modern power distribution system, standalone direct current (DC) microgrids are progressively explored. Important issues in DC microgrid operation are to ensure voltage regulation and proportional power sharing among sources. To solve these problems, comprehensive control scheme is presented for proportionate power sharing and better voltage regulation. A pivot element of this approach is formation of different power pools based on the accessible power from every renewable energy sources (RESs). In addition, it executes the coordinated operation of all power pools for effective power management. It is possible to make effective use of the energy storage systems (ESSs) by reducing their charging/discharging. Experimental studies prove the capabilities of the proposed scheme.

This paper deals with standalone coordinated operation of multiple electric vehicle charging stations (EVCS). A hierarchical control scheme is proposed to achieve power management among multiple EVCS. Each EVCS includes renewable energy source (RES), energy storage system (ESS), and controllable charging slots. The proposed control method maintains constant load demand on sources by compensating EVCS dynamic locally. Therefore, the sources are free from transient in EVCS. This improves the stability of system. The proposed control also improves the voltage regulation at each bus in the system under various operating conditions. The combined operation of sources and local controller in each EVCS achieves effective power management in the system. In absence of sources, the EVCS operates as voltage source and its smooth transition of EVCS is possible with proposed control scheme. The proposed control technique is tested under different operating condition in real time simulator.

In the past few years, the DC microgrid has become popular and preferable due to the advancement in controlled operation of converters and DC loads. This leads to multiple DC microgrids and their combined operation. In this paper, a hierarchical control method is proposed to achieve effective power management among multiple DC microgrids. It also improves the bus voltage regulation of the system. Every microgrid consists of renewable energy sources (RESs), energy storage system (ESS) and loads. The proposed control scheme operates in coordination with local controller of individual microgrid. It achieves power sharing among various microgrids based on power availability and local load demand. The local controller for microgrid mitigates the disturbance locally. The combined operation along with communicated signals achieves the effective power management. The proposed control technique is tested under diversified operating condition in real time simulator.

DC microgrid cluster plays an important role for efficient operation and coordinated power sharing between multiple DC microgrids. A non-isolated DC-DC bidirectional cluster converter is introduced for interconnecting DC microgrids. The proposed system architecture and control scheme is used for power sharing amongst three microgrids of different voltage level. The proposed power control algorithm identifies excess and deficiency of power in each microgrid and accordingly provides control signal to cluster converter. The cluster converter provides a coordinated control to maintain voltage level of microgrids while sharing the power between them. The operation of proposed cluster converter is verified in MATLAB under various operating conditions.

DC microgrid has unique characteristics which attracted more attention of researcher, but the identification and isolation of short circuit fault in DC microgrid is challenging task. Hence for assuring the normal work of microgrid the isolation methods and dc circuit breaker plays an important role. In this article, scheme is proposed to avoid the tripping of converter used in dc microgrid(DCMG) by implementing a algorithm to increase tripping time of converter under fault condition. First, this article makes a comprehensive analysis of the various working stages of the circuit when the fault occurs in the system. Then, the components for the increasing the tripping time through the calculation and analysis of the circuit is given in this paper. Finally, the performance of the novel algorithm is verified by experiment using MATLAB/Simulink environment for 96V DCMG having ring configuration which operated in islanded mode.

Digital simulation of an induction motor is beneficial for getting an insight into its dynamic performance and electro-mechanical interaction. A convenient model aids the simulation of faults. It also helps to predict the deviation in concerned parameters without conducting the actual experimentation. This paper presents dq, 2 axis model of three-phase induction motor with the stator winding inter-turn faults using stationary reference transformation, when the d and q axes do not rotate. The mathematical model and a MATLAB/Simulink based virtual model are developed for healthy and stator inter-turn fault conditions. The pulsations in speed and torque characteristics of the induction motor and increase in the stator winding current of faulty phase furnish the impact of the inter-turn fault on the particular phase of the stator winding. Simulated results analysis incorporates to mark the presence of inter-turn fault in the motor.

Distribution transformers (DTs) are an equipment of potential importance in the distributed grid. Distribution Transformer (DT) is the major component in the integrated architecture of power system. Power transformer and distribution transformer are critical component for generation, transmission and distribution utility. Its failure monitoring and diagnosis are important for a reliable power system since it is the connecting link between consumer and utility. The distribution transformers are installed at different locations in a power system. They are important in the electricity supply system as they feed power supply to the end users. Because large number of transformers are distributed over a wide area in power system network, the data acquisition and condition monitoring (CM) is an important issue. A transformer failure results in considerable losses for the energy supplier and society. Thus, transformer conditioning monitoring is becoming popular. Monitoring the condition of the transformer helps to extend service life, reduce the risk of failure of expensive devices and increase reliability to a high level. The various condition monitoring methods described in this document are useful for power transformers and distribution transformers.

The grid connected solar photovoltaic (PV) are widely utilized. However, in absence of grid, the available power in solar PV remains unutilized. This article suggests control scheme for off grid photovoltaic system, which consists of multiple sources. A centralized control scheme is proposed to achieve better voltage regulation of the system under dynamic conditions. The proposed control technique ensures minimum burden on voltage source. The maximum utilization of sources is achieved using proposed control scheme. The proposed controller allows transient free transition from on grid to off grid. The modified voltage control in standalone mode allows better voltage regulation and transient free operation on changes in the load demands. The modified proposed control scheme in off grid mode ensures minimal burden on the voltage source. A complimentary revised control method is proposed to ensure active power injection based on the availability of source power and the reactive power is supplied as required by the local loads.

In the past few years, the Direct Current Microgrid (DCMG) has become popular and preferable due to the advancement in converters and DC loads. However, the protection challenges and standardization issues of the microgrid have created obstacles to the widespread adoption of DCMG. This article is a summary of recent research conducted in the field of microgrid protection. Along this line, the voltage levels, topologies, and methods of grounding are reviewed first. Afterwards, the challenges in DC microgrid are discussed in brief. This study also analyzes and briefly outlines the latest developments for fault detection, location, and isolation in DC microgrid protection. Additionally, the protective devices for DC microgrid are also discussed. It is hoped that the proposed work will help researchers to find relevant references in the field of DC microgrid protection.

All industries requires active as well as reactive power for their motive load. For optimum utilization of the generator, reactive power requirement is to be fulfill at the load center. To encourage the industrial consumers previously there was a provision of incentive / penalty for PF in the billing system in Maharashtra. Now as per MERC new tariff order, from April 20, KVAH billing has been implemented. In which reactive power (Lag+Lead) is considered for the kVAH calculation and penalty has been withdrawn. Since March 20, due to COIVID-19, Lockdown has been implemented in all over India and all industries were running on No load condition. In such situation the industries those having power cable on high voltage level for extending the supply from metering system to distribution transformer, they have to bear additional kVAH billing due to RkVAH used due to power cable. This may introduced high voltage problem also. Two case studies has been presented here and suggested that, Shunt reactor can be used for compensation of the cable reactance. This will reduce the loss level in distribution network as well as burden on the industries in terms of revenue due to consumption of reactive power in power cable.

The power system oscillations in the grid are an issue of concern to the system operator. They may transform a stable system into an unstable system when the system is operating on the edge and contingency occurs. The oscillations developed in the system may grow and spread across the power grid if no timely, corrective action is taken to mitigate them. The paper presents the ultra-mega power plant generation complex related blackout analysis. The case study presented in this paper demonstrates the utilization of synchrophasor data to have a better realization about the grid disturbance. It covers some of the important dynamic simulation studies considered representative of various scenarios during this. The paper illustrates utilization of Prony analysis using multiple signals and Fast Fourier Transform methods in conjunction with frequency data obtained in real-time from PMUs installed in the western regional grid of India to determine the frequency of oscillations, its magnitude, and related damping during this disturbance. The focus of this study involves the application of these techniques to gain insight into the oscillatory behavior of the system during this disturbance associated with ultra-mega power plant having generation capacity greater than or equal to 4000 MW from the western part of Indian grid. Based on this, distinct categorization of oscillations into “local mode” and “inter-area mode” of oscillations was done for enhanced understanding about the type of oscillations getting excited during this disturbance.

The advances in Wide Area Measurement Systems (WAMS) and deployment of a huge number of phasor measurement units (PMUs) in the grid are generating big data volume. This data can be used for a variety of applications related to grid monitoring, management, operation, protection, and control. With the increase in this data size, the respective storage capacity needs to be enhanced. Also, communication infrastructure readiness remains bottleneck to transfer this big data. One of the probable solutions could be transmitting compressed data. This paper presents techniques for data compression in the smart transmission system using singular values decomposition (SVD) and the eigenvalues decomposition (EVD). The SVD and EVD based principal component analysis (PCA) techniques are applied to the real-time PMU data collected from extra-high voltage (EHV) substations of transmission utility in the western regional grid of India. Adequacy of data is checked by Kaiser-Meyer-Olkin (KMO) test in order to have the satisfactory performance of these techniques towards achieving the objective of efficient data compression. Results are found satisfactory gives compression more than 80% using real time data.

This article proposes a protection scheme/method based on oscillation frequencies of current in ring type DC microgrid (DCMG). The proposed method modifies the differential current algorithm in presence of high di/dt, high fault resistance and during light load condition, etc. A differential protection scheme which is based on the differences between current component of respective oscillation frequency measured at both the end of line section, is proposed to detect and isolate the faults. The 96V DCMG having ring configuration and its proposed protection scheme is implemented and simulated using MATLAB/Simulink environment, modelled to operate in an islanded mode.

An isolated four channel dc/dc converter with zero voltage switching is proposed as the front-end of multiple inverter structures to integrate renewable and other low voltage energy sources to micro grids. The interleaving technique is adopted to connect each module of proposed converter to a common dc source. This dc source can be a fuel cell stack, PV panels, battery, or any other low voltage dc source. All four channels are interleaved and a phase shift of $90^{\circ }$ is provided between the gate signals of each channels, which reduces the input current ripple. The output port of the proposed converter provide four isolated and regulated dc voltages. These isolated dc sources can be connected in series or parallel or series-parallel manner to obtain required dc-link voltage of various inverter structure. Issues like capacitor voltage balancing of diode clamped multilevel inverters can overcome through the proposed converter. By incorporating a coupled inductor for isolation and energy storage along with voltage multiplier circuit, the proposed converter can achieve higher voltage step up with lower turns ratio and lower voltage stress at moderate duty ratio. Hence, mosfet s of low voltage rating (low $R_{DS}(\text{ON})$ ) can be utilized to reduce conduction loss. A 2 kW prototype of the proposed interleaved dc/dc converter is developed and tested with diode clamped three-level inverter, five-level inverter, and three-phase two-level inverter to verify the design.

Indian power system is characterized by cluster of Extra High Voltage Alternating Current (EHVAC), High Voltage Direct Current (HVDC), Ultra High Voltage Direct Current(UHVDC), Multi-Terminal HVDC (MTDC-HVDC) transmission network, large distribution network across the country along with conventional generation having Ultra Mega Power Plants (UMPP) and increasing penetration of Renewable Energy Sources (RES). In such a scenario, the System Integrity and Protection Schemes (SIPS) plays important role in maintaining a secure, reliable grid and assists in effective grid management in India during conditions severe than (N-1) contingencies, disturbances/occurrences. This paper discusses the operational experience of implementing SIPS schemes in India. The operational experience of two prime SIPS schemes, one in the Northern Regional (NR) part of India and another in the Western Regional (WR) part of India are presented in this paper. Utilization of synchrophasor/Wide Area Measurement Systems (WAMS) in understanding the behaviour of the grid during major contingencies in these regions and subsequent operation of SIPS to tackle them is also explained in brief. In order to assess quantitatively the reliability of SIPS, there has to be a set of performance indices. This paper proposes a procedure for evaluating the performance of SIPS. It highlights the method for calculating Dependability index (D), Security index (S) and Reliability index (R) for SIPS based on the actual operational field data of SIPS in the Indian context.

This study presents a method to establish the harmonic injection responsibility of either utility or consumer or both at the energy metering point. The method involves voltage and current harmonic components extraction using fast discrete stockwell transform (FDST). FDST overcomes the limitations of fast Fourier transform (FFT) and thus gives more accurate magnitude and phase angle information of harmonic components irrespective of noise effect. These harmonic components are utilised in phasor analysis to derive harmonic indices which arbitrates the responsible source for harmonic injection at the metering point. Energy billing is proposed based on evaluation of percentage harmonic injection responsibility which eradicates the drawback of conventional billing method. Several experimental cases are presented in order to validate the reliability, accuracy and effectiveness of the proposed technique for different supply and loading conditions. The proposed method is implemented over LabVIEW to show its feasibility in real-time scenario. The proposed energy billing scheme can be implemented in the existing energy meters and harmonic contribution share is easily attainable without any prior knowledge of network parameters.

The Power Quality (PQ) gets affected not only because of the load but also because of the source as power electronics devices applications are widely spread in both sides. The renewable energy sources used power electronics converters and the nonlinear loads connected at consumer premises are the main causes of PQ distortions. This hampered PQ supply, when fed to equipments (or loads), affect the performance of them by increasing the energy lose, increasing the electricity bill and reducing their life expectancy. This article proposed a model for the analysis of different PQ events by means of Wavelet Transforms (WT) and Artificial Neural Network (ANN) composition. The different types of PQ events are generated in the laboratory under the source and load distortion conditions. The supply side voltage waveforms under linear load condition and load side current waveforms under normal supply conditions are considered for analysis. These waveforms are processed by WT and the scaling coefficients are determined for various PQ events. These coefficients are used to train ANNs for decision making. The proposed model is developed in MATLAB for offline and online applications. The results obtained by both the methods are compared and found satisfactory. At the end, the losses incurred in the transformer considered for performance, its efficiency and life expectancy are presented for different PQ conditions.

This paper presents the hybrid control of a dc–dc resonant converter for a dc micro-grid. The hybrid control is the simultaneous variation of the frequency and the duty ratio, which can provide excellent voltage regulation and maintain zero-voltage switching (ZVS) over a wide load range. Hence, excellent conversion efficiency is also maintained over the wide load range using hybrid control. However, the conventional control methods for a dc–dc resonant converter using either variable switching frequency or duty ratio have their own limitations. The frequency control requires wide variation in switching frequency for output voltage regulation, which leads to higher switching losses at turn-off of switches and lower efficiency particularly at light loads. The duty ratio control has a limitation of loosing of ZVS at light loads. The simulation and experimental results of hybrid control of resonant converter operating above 100 kHz with maximum duty ratio of 0.48 for 3 kW are presented from full load to no load. The maximum efficiency of the resonant converter is found to be 98%, which was achieved at 75% of the full load.