Faculty Publications
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Item Performance enhancement of electrical distribution systems with multiple distributed generation sources(2010) Krishnamurthy, M.; Vittal, K.P.The recent trends in electrical power distribution system operation and management are aimed at improving system conditions in order to render good service to the customer. Reforms in the distribution sector have given major scope for employment of distributed generation (DG) resources which will boost system performance. This article proposes a heuristic technique for allocation of multiple distribution generation sources in a distribution system. The allocation is determined based on overall improvement in network performance parameters like reduction in system losses, improvement in voltage stability, improvement in voltage profile. The hybrid of Genetic Algorithm with the proposed Network Performance Enhancement Index (NPEI) along with the heuristic rules facilitates determination of feasible location for insertion of DG sources. A priority list is prepared with decreasing values of NPEI so that the designer can select most feasible locations. The developed approach is tested with different test systems to ascertain its effectiveness.Item Investigation on electromagnetic transients of distributed generation systems in the microgrid(2010) Gaonkar, D.N.The increasing interconnection of distributed generation sources of diverse technologies to low-voltage grids introduces considerable complexity in its operation and control. The concept of the microgrid is emerging as a solution to this and also to take full advantage of the potential offered by distributed generation. In this article, the performance of a typical microgrid with multiple distributed generation systems in grid-connected and autonomous modes of operation has been investigated through simulation. The developed model of the microgrid consists of a converter-interfaced microturbine generation system, a synchronous-generator-based distributed generation system, and a wind power generation system with an asynchronous generator. Investigation has been carried out to study the typical electromagnetic transients of a microgrid, due to preplanned and unplanned switching events. The performance of the bidirectional grid interface topology for a microturbine generation system in a microgrid is evaluated in this work. It has been observed from the simulation results that the motoring mode operation of the microturbine generation system during starting does not cause any disturbances in the microgrid. The study also indicates that the microgrid can maintain the desired power quality at the point of common coupling. Copyright © Taylor & Francis Group, LLC.Item Coordinated voltage regulation of distribution network with distributed generators and multiple voltage-control devices(2012) Shivarudraswamy, R.; Gaonkar, D.N.In recent years, there has been a considerable increase in the number of generators connected to distribution networks. While offering a number of benefits and opportunities, increasing penetration of distributed generation systems can cause several technical concerns. One major concern is the rise in steady-state voltage level of a distribution system. This is very important, as distribution networks are traditionally designed to maintain customer voltage constant, within tolerance limit as dictated by statute. The present practice of limiting generation capacity cannot be a solution, as it leads to under-utilization of distributed generation sources. In this article, coordinated voltage regulation of distribution system with distributed generators is presented. The developed method uses the genetic algorithm to determine the optimal operating point for multiple voltage-control devices. The simulated results using the developed method are presented in this article, considering the time-varying load profile. The fuzzy-clustering technique is also employed to obtain the load pattern for the simulation. The reported results show that the method presented is capable of providing the voltage profile within the statute limits. © 2012 Taylor and Francis Group, LLC.Item Operation of the Microgrid with Improved Droop Control Strategy and an Effective Islanding Detection Technique for Automatic Mode Switching(Taylor and Francis Ltd., 2021) Kulkarni, S.V.; Gaonkar, D.N.; Guerrero, J.M.This paper presents the islanding detection and automatic mode switching for inverter-based distributed generation sources (DGs) in the microgrid with an improved droop controlled scheme. The modification in the conventional droop among the DGs is contrived to share the load proportionate to their power capacity. And to reduce the circulating currents and to improve reactive power-sharing the virtual impedance is implemented for the microgrid in the stand-alone mode operation. Also, the modified Park synchronous reference frame based phase-locked loop (PSRF-PLL) is implemented for the operation of the microgrid in the grid-connected mode. The islanding detection and automatic mode switching depend on the PSRF-PLL, which uses the input obtained from the stationary reference frame. The proposed PLL implemented in this work is simple in construction and keeps the phase locking error to near zero, thus leading to proper locking with reduced complexity. The control scheme's performance in the microgrid is validated using the real time hardware in the loop platform. The performance of PSRF-PLL based islanding detection scheme is analyzed considering the various grid disturbances, and the comparative study with the other PLL based scheme is also presented in this paper to show the improved performance of the proposed PSRF-PLL scheme. © 2021 Taylor & Francis Group, LLC.Item A Novel Islanding Detection Technique Based on Piezoelectric Sensors for Grid-Integrated DG Systems(Taylor and Francis Ltd., 2023) Kulkarni, S.V.; Hegde, V.; Gaonkar, D.N.This paper presents the novel islanding detection technique that depends on the piezoelectric sensors for distributed generation sources (DGs) in the grid-integrated operation mode. The islanding detection method employs a piezoelectric sensor for the detection of the frequency variations during grid disruptions. The designed diaphragm-based sensor has a natural frequency as that of the fundamental frequency of the system frequency signal. Any further deviations from the natural frequency due to the disturbances will be sensed by the sensor and a control signal is being sent to the associated circuit breaker for suitable action. The sensor structure is modeled using the finite element method and implemented in the Phase-Locked Loop (PLL) of the grid-integrated DGs. The proposed circular diaphragm-based sensor structure will have the bandwidth in the range of natural frequency with the tolerance rate of ±1% and uses the input signal received from the PLL controller outer loop. The proposed islanding detection technique’s performance and reliability for grid-integrated DG are validated using the real-time hardware in the loop test-bed platform. The HIL virtual simulated responses show that the method can be proposed effectively for islanding detection in the event of frequency variations in the grid-integrated DG systems. © 2023 IETE.