scholarly journals Transformer for Single-phase Line Break Fault in Low Voltage Three-phase Distribution System

Author(s):  
Cheng Guo ◽  
Zhiyuan Chen ◽  
Fulin Zhou
Author(s):  
Kartik Prasad Basu ◽  
Moley Kutty George

Most faults in medium voltage (MV) distribution lines are temporary line to ground (LG) faults. Three-phase auto reclosing (TPAR) is commonly used to remove this fault with temporary disconnection of all the phases. Multi-shot single-phase auto reclosing (SPAR) may also be used to remove the LG fault. But it produces highly unbalanced and low voltage across the load during the reclosure dead time. It is proposed to connect a zigzag winding grounding transformer at the load bus to maintain the 3-phase load voltage when one phase opens during the SPAR. With low value of grounding resistance the 3-phase voltage during the SPAR dead time becomes approximately balanced. Directional over current relays may be used for the protection. Analysis of a MV radial distribution system having a zigzag transformer connected to the remotest load bus is presented with the computation of voltages during the dead time of SPAR.


2021 ◽  
Author(s):  
Heiner Früh ◽  
Krzysztof Rudion ◽  
Alix von Haken ◽  
Daniel Groß ◽  
Bartholomäus Wasowicz

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yongheng Yang ◽  
Frede Blaabjerg

The progressive growing of single-phase photovoltaic (PV) systems makes the Distribution System Operators (DSOs) update or revise the existing grid codes in order to guarantee the availability, quality, and reliability of the electrical system. It is expected that the future PV systems connected to the low-voltage grid will be more active with functionalities of low-voltage ride-through (LVRT) and the grid support capability, which is not the case today. In this paper, the operation principle is demonstrated for a single-phase grid-connected PV system in a low-voltage ride-through operation in order to map future challenges. The system is verified by simulations and experiments. Test results show that the proposed power control method is effective and the single-phase PV inverters connected to low-voltage networks are ready to provide grid support and ride-through voltage fault capability with a satisfactory performance based on the grid requirements for three-phase renewable energy systems.


Author(s):  
Shuchi Vishnoi ◽  

This paper is intended to simulate a power quality conditioning device, Unified Power Quality Conditioner (UPQC), in countryside areas for non-linear loading. From past decades there is much increase in the requirement of the good quality electrical power in single phase distribution grids established in these locations. Due to technical advancement, three-phase loads are practiced more than single phase loads so that the demand for three phase distribution grids is growing. But the installation process of three-phase grids, at countryside areas, is not an economic option and to get access to these systems is a very challenging task. So a neighbouring three-phase distribution system is required to be established at the location, where single-phase to three-phase UPQC with single wire earth return is appropriate for the end user due to economic considerations. A dual compensation strategy is implemented to obtain the reference quantities for controlling the converters. The proposed idea is accomplished to eliminate voltage harmonics and mitigate further instabilities and power quality problems. This system allows the balanced and regulated voltage with lower harmonic content. Synchronous Reference Frame (SRF) based controllers are considered to organize the input grid current and the load voltages of the UPQC. The present prototype under consideration analyses and validates the compensation and controlling techniques using PI controller. The control strategies are simulated using MATLAB/SIMULINK.


2015 ◽  
Vol 135 (3) ◽  
pp. 168-180 ◽  
Author(s):  
Ryota Mizutani ◽  
Hirotaka Koizumi ◽  
Kentaro Hirose ◽  
Kazunari Ishibashi

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