Design and Implementation of Hybrid Active Power Filter (Hapf) for UPS System Mahendar Kumar1*, Zubair .A Memon1, M .Aslam Uqaili1-1Institute of Information & Communication Technologies (IICT) Mehran University of Engineering & Technology (MUET), Jamshoro Sindh, 76090, PAKISTAN

Design and Implementation of Hybrid Active Power Filter (Hapf) for UPS System Mahendar Kumar*, Zubair .A Memon, M .Aslam Uqaili 

Abstract: 

Hybrid Active Power Filter (HAPF) is designed and applied for Uninterrupted Power Supply (UPS) System to mitigate harmonic currents in UPS during the power conversion from rectifiers to inverters (AC-DC-AC Converters). Various UPS types and topologies are used for continuous power supply without delay and protection to connected loads. In spite of the fact that UPS is one of the power quality apparatus but it has also drawback of disturbing the power system quality of system by current harmonics and voltage distortion during conversion of power. Passive and EMI Filters could not eliminate harmonics effectively from UPS system therefore it requires modern, rapid filtering method as well combination of Active and Passive Filters. Proposed model of HAPF for UPS System could mitigate current harmonics for optimal power transfer and minimize losses, increase overall efficiency, reliability and life span of equipment. Higher harmonic current and higher voltage distortion leads to greater power loss. In this paper the (d-q) theorem is applied for the identification of harmonic currents. The d-q theorem and calculation creates the signal of reference compensation current and this produced signal of current is tracked by the yield current of the voltage source converter.. Hysteresis based controller for HAPF is applied to create the switching signals to regulate and maintain the voltage source converter output currents. Harmonics and efficiencies are analyzed at different loads and on charging and discharging of batteries of various UPS System in different industries and sectors on the basis of experimental investigation then HAPF is designed and implemented. In simulation results, it is observed that THD reduced from 46 to 10%, the harmonic currents were compensated and eliminated effectively which improved power quality of UPS System. Furthermore, addition of proposed HAPF could save the power up to 15 % which lost due to poor power quality of UPS System.

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https://publisher.uthm.edu.my/ojs/index.php/ijie/article/download/6727/3715/

Pulse Circuits by V.T. Frolkin; L.N. Popov

 

Pulse Circuits by V.T. Frolkin; L.N. Popov 

 This book explains the analysis and operation of all the most frequently used pulse circuits. It covers solid-state circuits, including their IC forms. The text contains a large number of problems and review questions that will help the reader to get better insight into the subject-matter. The authors start with pulse waveforms, move through RS-networks, to diode and transistor switching, logic gates, various forms of multivibrators, and flipflops as building blocks for the more complex networks. The material also covers sawtooth voltage and current generators, relaxation oscillators, and their applications.

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https://archive.org/details/v.-t.-frolkin-l.-n.-popov-pulse-circuits-mir-1982

IET Renewable Power Generation Research - Optimal sizing of a wind/solar/battery hybrid grid-connected microgrid system-José Luis Monroy-Morales, Rafael Peña-Alzola2,Rafael Sebastián-Fernández, David Campos-Gaona,Jerónimo Quesada Castellano, José L. Guardado

 Frequency control in an isolated wind-diesel hybrid system with energy storage and an irrigation water supply system José Luis Monroy-Morales1 Rafael Peña-Alzola2 Rafael Sebastián-Fernández3 David Campos-Gaona2 Jerónimo Quesada Castellano4 José L. Guardado 1Electrical Engineering, TecNM/Instituto Tecnológico de Morelia, Morelia, Mexico 2Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK 3Department of Electrical, Electronic and Control Engineering, UNED, Madrid, Spain 4Electronic Technology, University of the Basque Country, Vitoria, Spain

 Abstract 

Wind-Diesel Hybrid Systems (WDHSs) integrate wind turbines into diesel power systems, reducing costs and emissions in isolated grids. Due to the no-load consumption of the Diesel Generators (DGs), fuel savings are only possible when the DGs are shut down. This requires a proper implementation of the frequency control to avoid perturbations because of the wind speed variations. During wind-only (WO) operation, the Synchronous Machine (SM) generates the isolated grid voltage and the frequency controller varies the energy stored/supplied by an Energy Storage System and consumed by the controllable loads to balance the power. In this paper, a Battery-based Energy Storage System (BESS) uses Li-Ion batteries with a Dual Active Bridge (DAB) and a grid-tie inverter connected to the isolated network. The controllable load is an Irrigation Water Supply System (IWSS), consisting of a pump supplying water to a reservoir tank. The pump is driven by a variable speed drive that uses a Permanent Magnet Synchronous Motor (PMSM). The coordinated control of BESS and IWSS gives full priority to the BESS for harnessing the wind potential whereas the IWSS consumes the excess of wind power. The full Wind Diesel Power System (WDPS) is modelled and simulated to validate the proposed system for different case scenarios.

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https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/rpg2.12950

Optimal sizing of a wind/solar/battery hybridgrid-connected microgrid system-BY-Umer Akram, Muhammad Khalid, Saifullah Shafiq, Department of Electrical Engineering, King Fahd University of Petroleum & Minerals (KFUPM), Dhahran 31261, Saudi Arabia

 IET Renewable Power GenerationResearch ArticleOptimal sizing of a wind/solar/battery hybridgrid-connected microgrid system Umer Akram1 , Muhammad Khalid1, Saifullah Shafiq1 1Department of Electrical Engineering, King Fahd University of Petroleum & Minerals (KFUPM), Dhahran 31261, Saudi Arabia E-mail: g201512930@kfupm.edu.sa

 Abstract: Higher cost and stochastic nature of intermittent renewable energy (RE) resources complicate their planning,integration and operation of electric power system. Therefore, it is critical to determine the appropriate sizes of RE sources andassociated energy storage for efficient, economic and reliable operation of electric power system. In this study, two constraint-based iterative search algorithms are proposed for optimal sizing of the wind turbine (WT), solar photovoltaic (PV) and thebattery energy storage system (BESS) in the grid-connected configuration of a microgrid. The first algorithm, named as sourcessizing algorithm, determines the optimal sizes of RE sources while the second algorithm, called as battery sizing algorithm,determines the optimal capacity of BESS. These algorithms are mainly based upon two key essentials, i.e. maximum reliabilityand minimum cost. The proposed methodology aims to avoid over- and under-sizing by searching every possible solution in thegiven search space. Moreover, it considers the forced outage rates of PV, WT and utilisation factor of BESS which makes itmore realistic. Simulation results depict the effectiveness of the proposed approach.

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A Unified Control and Power Management Scheme for PV-Battery-Based Hybrid Microgrids for Both Grid-Connected and Islanded Modes Zhehan Yi, Student Member, IEEE, Wanxin Dong, and Amir H. Etemadi, Member, IEEE

 A Unified Control and Power Management Scheme for PV-Battery-Based Hybrid Microgrids for Both Grid-Connected and Islanded Modes 

Zhehan Yi, Student Member, IEEE, Wanxin Dong, and Amir H. Etemadi, Member, IEEE 

 Abstract 

 Battery storage is usually employed in Photovoltaic (PV) system to mitigate the power fluctuations due to the characteristics of PV panels and solar irradiance. Control schemes for PV-battery systems must be able to stabilize the bus voltages as well as to control the power flows flexibly. This paper proposes a comprehensive control and power management system (CAPMS) for PV-battery-based hybrid microgrids with both AC and DC buses, for both grid-connected and islanded modes. The proposed CAPMS is successful in regulating the DC and AC bus voltages and frequency stably, controlling the voltage and power of each unit flexibly, and balancing the power flows in the systems automatically under different operating circumstances, regardless of disturbances from switching operating modes, fluctuations of irradiance and temperature, and change of loads. Both simulation and experimental case studies are carried out to verify the performance of the proposed method.

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https://www.researchgate.net/publication/316655655_A_Unified_Control_and_Power_Management_Scheme_for_PV-Battery-Based_Hybrid_Microgrids_for_Both_Grid-Connected_and_Islanded_Modes