Faculty Publications
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Item Fuzzy logic based coordinated voltage regulation method for distribution system with multiple synchronous generators(2010) Gaonkar, D.N.; Pillai, G.N.The continued interest in the distributed generation (DG) sources in recent years is leading to the growth of a number of generators connected to distribution networks. The steady-state voltage rise resulting from the connection of these generators can be a major obstacle at the lower voltage levels. Present network design practice is to limit the generator capacity to a level at which the upper voltage limit is not exceeded. This reduces the efficiency of DG system. This paper proposes a coordinated voltage control scheme using fuzzy logic based power factor controller, for distribution network with multiple Distributed generation systems. In the proposed scheme individual generators participate in voltage regulation of the distribution system, based on their participation factor determined using sensitivity analysis. The simulation results presented in the paper show the effectiveness of the method. © 2010 IEEE.Item Fuzzy logic based coordinated voltage regulation method for distribution system with multiple synchronous generators(2010) Gaonkar, D.N.; Pillai, G.N.The continued interest in the distributed generation (DG) sources in recent years is leading to the growth of a number of generators connected to distribution network. One of the major concern due to connection of these generators is the rise in steady state voltage level of distribution system. Present network design practice is to limit the generator capacity to a level at which the upper voltage limit is not exceeded. This reduces the efficiency of DG system. This paper proposes a coordinated voltage control scheme using fuzzy logic based power factor controller, for distribution network with multiple synchronous generators. In the proposed scheme individual generators participate in voltage regulation of the distribution system, based on their participation factor determined using sensitivity analysis. The simulation results presented in the paper show the effectiveness of the method. © 2010 IEEE.Item Voltage estimation in smart distribution networks with multiple DG systems(Institute of Electrical and Electronics Engineers Inc., 2016) Raghavendra, P.; Gaonkar, D.N.Steady state voltage rise problem resulting from the integration of DGs at lower voltage levels can be a major impediment to the growth of distributed generation capacity. With the steady implementation of the smart grid technologies throughout the existing distribution networks, the online voltage control can be achieved. The voltage profile has to be estimated first along the distribution networks for the online voltage control. In this article, a technique to estimate the voltage profile of a radial distribution network with multiple DG systems having different line section impedances with/without laterals is presented. The presented technique is based on estimation of voltages by remote terminal units (RTUs) placed at each DG and at each line capacitor. The presented technique tested on two radial rural distribution systems with/without laterals. Comparative results for different methodologies in estimating the voltage profile are presented. The simulated results using the above method are presented in this paper, considering the multiple DG systems with/without laterals. The reported results show that the method presented is capable of estimating the voltage profile along the distribution network with DGs for online voltage control. © 2015 IEEE.Item Online volt/var control in a smart grid with multiple distributed generation systems(Institute of Electrical and Electronics Engineers Inc., 2017) Raghavendra, P.; Gaonkar, D.N.The higher shares of distributed generation (DG) sources lead to unpredictable rise in voltage level due to intermittent and stochastic characteristics of DGs. This paper intends to report the online Volt/Var control in a smart grid with multiple DG systems. The objective of Volt/Var control is to recover the network voltages within the admissible limits by coordinating the operation of the DG and the OLTC transformer. Firstly, voltage profile of the system is estimated by remote terminal units (RTUs) placed only at DG node. Next, a direct voltage sensitivity based method is developed to choose best DG for reactive power injection in multiple DG environments. Finally, OLTC transformer is employed in voltage regulation process when DGs reactive power is insufficient for maintaining the voltages within predefined limits. The reported method tested on 12-bus radial distribution network to validate the theory. The reported simulation results show that the presented method effectively maintains network voltages within admissible limits. © 2016 IEEE.Item Dynamic performance of microturbine generation system connected to a grid(2008) Gaonkar, D.N.; Pillai, G.N.; Patel, R.N.The interconnection of distribution generation systems into distribution networks has great impact on real-time system operation, control, and planning. It is widely accepted that microturbine generation (MTG) systems are currently attracting a lot of attention to meet customers' needs in the distributed power generation market. In order to investigate the performance of MTG systems, their efficient modeling is required. This article presents the dynamic model of an MTG system, suitable for grid connection to study the performance of the MTG system. The presented model uses back-to-back power electronic converter topology for grid connection, which allows the bidirectional power flow between the grid and MTG system. Thus, the need of separate starting arrangements during launching of the microturbine is avoided. The components of the system are built from the dynamics of each part with their interconnections. The dynamics of the model have been studied under various grid disturbance conditions. The converter control strategies for MTG system operation in grid-connected mode are presented in this article. This article also compares the various grid connection topologies suitable for MTG system interconnection. The simulation results show that the developed model performance is not affected by the grid disturbances considered in the study, and that it has the ability to adjust the supply as per the power requirements of the load within the MTG system rating.Item Seamless transfer of microturbine generation system operation between grid-connected and islanding modes(2009) Gaonkar, D.N.; Pillai, G.N.; Patel, R.N.The intentional islanding operation of grid-connected distributed generation systems can greatly improve the reliability and quality of the power supply. The existing control techniques for distributed generation systems are designed to operate either in the grid-connected or islanding modes of operation, thus, not allowing for both modes to be implemented and transitioned between. In this article, a novel scheme for automatic mode switching of a microturbine-based distributed generation system between the grid-connected and islanding modes of operation is proposed. The presented scheme is based on the phase angle estimated by the phase-locked loop. The developed phase-locked loop provides an accurate estimation of the phase angle even under unbalanced conditions. The presented scheme does not negatively affect the distributed generation system or utility operations and can work even under matching distributed generation and load power ratings. In this work, back-to-back converters are used to interface the microturbine-based distributed generation system to the grid. Converter control strategies developed for both modes of distributed generation operation is also presented. The simulation results show good accuracy of the proposed scheme.Item Multiple inverters operated in parallel for proportional load sharing in microgrid(Institute of Advanced Engineering and Science info@iaesjournal.com, 2017) Chethan Raj, D.; Gaonkar, D.N.The new energy source utilization and development, gradual rise of distributed power grid miniaturization, intelligence, control has become a trend. In order to make microgrid reliable and efficiently run, control technology of microgrid has become a top priority and an inverter as microgrid basic unit, its control has become the most important part in microgrid. In this paper, three inverters are operated in parallel using an P-V/Q-F droop control is investigated. Mathematical model of three phase inverter with LC filter is derived, which is based on the voltage and current dual control loop. Parallel control strategy based on P-V/Q-F droop control, does not require a real time communications between the inverters and more suitable for microgrid applications. To verify the feasibility and validity of the droop control scheme, simulation is done in Matlab/Simulink and results indicate droop control has significant effect on power sharing and balancing the voltage magnitude, frequency. © 2017 Institute of Advanced Engineering and Science. All rights reserved.