Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Voltage sag"”.
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Analyzing voltage sag direction using protective relays and deep-learning methods
… to study methods of identifying the direction of voltage sags in the distribution circuits. Voltage sags arise from the presence of short-circuit faults involving single, double, and three phase-to-ground conditions. The direction of the fault is based on the direction of power flow before the …
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Modeling of industrial power distribution circuits for voltage sag and fault analysis
… to simulate sensitive electrical loads during voltage sags. The study begins by discussing the modeling procedure for induction motors based on manufacturer datasheets. It then investigates and develops a 24-pulse variable frequency drive (VFD) model in EMTP. The functionality of the VFD model …
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Study on 6, 12 and 24 pulses D-STATCOM for voltage SAG mitigation
… technical problems occur at distribution system. Voltage sag is one of major problems. In the distribution system, voltage sag can occur in any point at any time. This issue always brought up for discussion by Electrical power committee all around the world. There are many causes of voltage sag …
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Development of D-Statcom in hardware in the loop system for voltage SAG mitigation
… most common types of power quality problems are voltage drops. The main causes of the voltage drop are due to a short circuit in the system, a switching operation, the starting of the large motor, a sudden increase in line loads, electrical fault on utility power lines caused by an animal, trees …
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Mathematical Modelling of Grid Connected Fixed- Pitch Variable-Speed Permanent Magnet Synchronous Generators for Wind Turbines
… (SVPWM) inverter, and a model of the power grid voltage sag detection for low voltage ride through (LVRT). The rectifier is a 3-phase uncontrolled diode full-bridge circuit. The boost chopper circuit offers a direct current (DC) power supply with constant voltage for the inverter. Sampled signals …
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A voltage-only method for estimating the location of transmission faults
… and illustrates with actual data, a new voltage-only based fault location procedure that incorporates the system impedance matrices into the problem so that as few as three or four voltage recording devices can estimate the fault location over a wide area. This procedure can quickly help …
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Modelling a hybrid system pv/wind grid connected with static synchronous compensator (STATCOM)
… at the grid side after many disturbances via Voltage Sag, load changes, Distortion etc. This thesis contain modelling of Photovoltaic renewable energy system to produces maximum 5 KW/h. Moreover, the study contains modelling of wind energy system to produces 1.5 KW/h. reducing the effect of …
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Modeling of doubly-fed induction generators connected to distribution system based on eMEGASim® real-time digital simulator
… studies such as three-phase to ground fault and voltage sag have been made to test the response of the model.
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Adaptive underfrequency load shedding based on real time simulation
… research discussed utilizing synchrophasor messages to implement adaptive UFLS but these studies have been using virtual PMUs. Of late, hardware implementations for adaptive UFLS scheme using actual Phasor Measurement Units (PMUs) are reported but also these studies are based on small power …
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Modeling and Analysis of a Dynamic Voltage Regulator
… often highly variable, resulting in undesirable voltage disruptions that are harmful to sensitive loads. In addition to the energy variability of renewable energy sources, random voltage sags, swells and disruptions are already a major issue in power systems. Recent advances in power electronic …
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Battery Pack Design and Transient Performance Modeling for High-Power Legged Robots
… battery model that captures transient voltage sag and time-dependent internal battery state, enabling more accurate prediction of feasible power delivery. Additionally, a custom high-power battery pack was designed to meet the power demands of the MIT Humanoid, emphasizing power …
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Specification, Placement, and Control of Fault Current Limiters In Power Systems
… systems is enhanced and the allowable range of voltage-angle differences is expanded during synchronization. The optimal placement of FCLs in a power system with a ring structure is also proposed. With this optimal placement, fault currents in any location can be limited, while the maximum …
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High-Frequency Transformer Design for Solid-State Transformers in Electric Power Distribution Systems
… active power flow control, harmonic suppression, voltage regulation, voltage sag compensation, and reduced size and volume.</p> <p>In this thesis, SST topologies are evaluated in order to determine their impact upon the transformer design. In addition, design considerations for core and wire …
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Second-generation high-temperature superconducting coils and their applications for energy storage
… SMES system dynamically and robustly. During a voltage sag compensation experiment, this SMES prototype monitored the power system and successfully compensated the voltage sag when required. By investigating the process of building a complete system from the initial design to the final …
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Ultracapacitor character analysis and its application in unified power quality conditioner as energy storage system
… is Paper II. A UPQC is to compensate both source voltage sag and load current imperfections in power distribution system. With the UCAP based Energy Storage System, the UPQC has an optimized power flow between UPQC and system during the transit state, also the UPQC's serial and shunt part has an …
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Detection and Classification of Disturbances in Islanded Micro-grid
Micro-grids are envisaged as single plug-and-play electrical systems that can operate either in grid-connected or islanded modes. Their main sources of power are renewable and are usually integrated through power electronic devices. These present new challenges to reliable operation of the system …
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Effect of dopamine on synchronous neuronal oscillations in the globus pallidus-subthalamic nucleus network
… activity can be sustained in vitro a 20o parasagittal slice of mouse midbrain was developed which preserved functional connectivity between the STN and GP. Mouse STN and GP cells were characterised electrophysiologically by the presence or absence of a voltage sag in response to …
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Reliability Studies of Distribution Systems Integrated with Energy Storage
… of these equipment because of short duration (voltage sag and momentary interruption) and long duration (sustained interruption) reliability events could be substantial. It is, therefore, necessary to consider these short duration reliability events in the reliability studies. This thesis …
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Low Voltage Ride-Through for Indirect Matrix Converter Based Open-End Winding Drives
… a niche product. High frequency common mode voltage (CMV) switching is a by-product of the ASDs operating at medium to high frequencies and cause bearing currents to flow, which damage the machine and reduce their lifetime. Elimination or reduction of common mode voltage is a well-researched …
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On-line Dynamic Security Assessment in Power Systems.
… in synchronism, it is also required that the bus voltages remain within acceptable limits. A transient disturbance and the following angular divergence of a group of generators can cause critical voltage sags at certain buses in the system. In this thesis assessment of such voltage sags is …
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