scholarly journals Thermal Analysis of Busbars from a High Current Power Supply System

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2288 ◽  
Author(s):  
Adrian Plesca
Keyword(s):  
Mathematical Model ◽  
Thermal Analysis ◽  
Thermal Behaviour ◽  
Power Supply ◽  
Power Distribution ◽  
Distribution Systems ◽  
Short Circuit ◽  
High Current ◽  
Power Circuit ◽  
Junction Points

Copper busbar technology is widely used with the aim to achieve electrical connections with power distribution systems because of their flexibility and compactness. The thermal analysis takes into account the heat conduction and convection of a copper busbar system used to supply a test bench with high currents in order to check the electro-thermal behaviour of power circuit breakers during overload and short circuit conditions. This paper proposes a mathematical model for busbars used within a high current power supply. The obtained thermal model can be used to analyse the thermal behaviour of busbars in steady-state conditions at different values of the electric current, cross-section and length of the busbar. Also, the mathematical model allows to calculate the temperature distribution along the busbar at different values of the contact resistances at junction points with other conductors. There is a good correlation between calculated, simulated and experimental results.

scholarly journals Digital technologies for monitoring and implementation of smart diagnostics of the isolation of power supply systems with isolated neutral in the operating mode

2021 ◽  
Vol 75 (2) ◽  
pp. 109-112
Author(s):  
N.P. Kondrateva ◽  
A.A. Shishov ◽  
R.G. Bolshin ◽  
M.G. Krasnolutskaya
Keyword(s):  
Power Supply ◽  
Power Distribution ◽  
Distribution Systems ◽  
Power Supply System ◽  
Single Phase ◽  
Short Circuit ◽  
Digital Technologies ◽  
Operating Mode ◽  
Supply System ◽  
Ground Faults

Nowadays, 75% of emergencies at power supply facilities are caused by single-phase ground faults. The currently used methods of thermal imaging and ultrasonic testing do not allow accurately identify the cause of accidents in electric power distribution systems. The current search generators, due to their low power, cannot cover the entire section of the diagnosed network. The article suggests the use of digital technologies for the intelligent diagnostics of the insulation of power supply system with insulated neutral in the operating mode, allowing on-line diagnostics of the network and analyzing the data obtained for the early prevention of emergency situations. In order to avoid disconnecting sections and diagnose the system in operating mode, it is proposed to check the system using a currentlimiting capacitor, which will be connected to the live parts of each phase under voltage and accurately determine the location of a single-phase short circuit for any number of feeders. The relevance of these studies is due to the fact that, for example, during two years at one of the manufactures 19 emergencies related to single-phase ground faults were recorded. Four of these cases led to a complete stop of the production. Therefore, the development of digital technologies for the implementation of smart diagnostics of the insulation of an energized power supply system with insulated neutral will be of interest to practitioners, scientists, researchers, graduate students and other specialists seeking to study the latest achievements in smart agribusiness for their subsequent application in the real world.

scholarly journals A DC-side fault-tolerant bidirectional AC/DC converter for power system in integration of low-voltage DC distribution systems

2021 ◽  
Author(s):  
Nikoo Kouchakipour
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Power Distribution ◽  
Distribution Systems ◽  
Low Voltage ◽  
Short Circuit ◽  
Power Converter ◽  
Software Environment ◽  
Medium Voltage ◽  
Dc Distribution

With the rising potential for the employment of low- and medium-voltage direct-current (dc) electric power distribution systems, most notably for a more efficient integration of plug-in electric vehicles and such other distributed energy resources as photovoltaic (PV) panels, there is a need for robust ac/dc electronic power converters that can interface such dc distribution systems with the legacy alternating current (ac) power system. Thus, this thesis proposes a new single-stage low-voltage three-phase ac-dc power converter that is simple structurally, en- ables a bidirectional power exchanges between the ac and dc distribution systems, and can handle short-circuit faults at its dc as well as ac sides. The proposed converter consists of three legs, corresponding to the three phases of the host ac grid, each of which hosting two full-bridge submodule (FBSM), in an architecture that can be regarded as a special case of the so-called modular multi-level converter (MMC). Thus, at the dc port each FBSM is connected in parallel with a corresponding capacitor, while the ac voltage of each phase is synthesized by the coordinated sinusoidal pulse-width modulation (SPWM) of the two corresponding FBSMs. This architecture allows the generation of low-distortion ac voltage while it also provides the converter with the very important dc fault current blocking capability since, upon the detection of a short circuit across the converter dc port, the switches of the FBSMs are turned off and disallow the flow of any dc current. The thesis also presents a mathematical model for the converter, for analysis and control design purposes. Thus, the control for the regulation of the overall dc-side voltage, as well as those for the regulation of the dc voltages of the FBSMs are devised based on the aforementioned mathematical model and presented with details. It is further shown that the voltage conversion ratio of the proposed converter is the same as that offered by a conventional voltage-sourced converter (VSC), whereas the VSC is vulnerable to dc- side shorts. The proposed converter can be extended to medium-voltage levels by multi- plying the number of FBSMs in each leg. The effectiveness of the proposed converter and its controls is demonstrated through time-domain simulation studies conducted on a topological model of the converter in PSCAD/EMTDC software environment.

scholarly journals A DC-side fault-tolerant bidirectional AC/DC converter for power system in integration of low-voltage DC distribution systems

2021 ◽  
Author(s):  
Nikoo Kouchakipour
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Power Distribution ◽  
Distribution Systems ◽  
Low Voltage ◽  
Short Circuit ◽  
Power Converter ◽  
Software Environment ◽  
Medium Voltage ◽  
Dc Distribution

With the rising potential for the employment of low- and medium-voltage direct-current (dc) electric power distribution systems, most notably for a more efficient integration of plug-in electric vehicles and such other distributed energy resources as photovoltaic (PV) panels, there is a need for robust ac/dc electronic power converters that can interface such dc distribution systems with the legacy alternating current (ac) power system. Thus, this thesis proposes a new single-stage low-voltage three-phase ac-dc power converter that is simple structurally, en- ables a bidirectional power exchanges between the ac and dc distribution systems, and can handle short-circuit faults at its dc as well as ac sides. The proposed converter consists of three legs, corresponding to the three phases of the host ac grid, each of which hosting two full-bridge submodule (FBSM), in an architecture that can be regarded as a special case of the so-called modular multi-level converter (MMC). Thus, at the dc port each FBSM is connected in parallel with a corresponding capacitor, while the ac voltage of each phase is synthesized by the coordinated sinusoidal pulse-width modulation (SPWM) of the two corresponding FBSMs. This architecture allows the generation of low-distortion ac voltage while it also provides the converter with the very important dc fault current blocking capability since, upon the detection of a short circuit across the converter dc port, the switches of the FBSMs are turned off and disallow the flow of any dc current. The thesis also presents a mathematical model for the converter, for analysis and control design purposes. Thus, the control for the regulation of the overall dc-side voltage, as well as those for the regulation of the dc voltages of the FBSMs are devised based on the aforementioned mathematical model and presented with details. It is further shown that the voltage conversion ratio of the proposed converter is the same as that offered by a conventional voltage-sourced converter (VSC), whereas the VSC is vulnerable to dc- side shorts. The proposed converter can be extended to medium-voltage levels by multi- plying the number of FBSMs in each leg. The effectiveness of the proposed converter and its controls is demonstrated through time-domain simulation studies conducted on a topological model of the converter in PSCAD/EMTDC software environment.

Influence of distributed power supply in distributed power distribution network

2021 ◽  
pp. 1-8
Author(s):  
Xin Shen ◽  
Hongchun Shu ◽  
Min Cao ◽  
Nan Pan ◽  
Junbin Qian
Keyword(s):  
Power Supply ◽  
Power Distribution ◽  
Short Circuit ◽  
Power Grid ◽  
Distribution Network ◽  
Distribution Networks ◽  
Power Supplies ◽  
Power Distribution Network ◽  
Power Sources ◽  
Distributed Power

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.

scholarly journals Active Reduction of Short-Circuit Current in Power Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Power Converter ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
In Series

In this paper, a new concept of short-circuit current (SCC) reduction for power distribution systems is presented and analyzed. Conventional fault current limiters (FCLs) are connected in series with a circuit breaker (CB) that is required to limit the short-circuit current. Instead, the proposed scheme consisted of the parallel connection of a current-controlled power converter to the same bus intended to reduce the amplitude of the short-circuit current. This power converter was controlled to absorb a percentage of the short-circuit current from the bus to reduce the amplitude of the short-circuit current. The proposed active short-circuit current reduction scheme was implemented with a cascaded H-bridge power converter and tested by simulation in a 13.2 kV industrial power distribution system for three-phase faults, showing the effectiveness of the short-circuit current attenuation in reducing the maximum current requirement in all circuit breakers connected to the same bus. The paper also presents the design characteristics of the power converter and its associated control scheme.

A Novel 4H-SiC Fault Isolation Device with Improved Trade-Off between On-State Voltage Drop and Short Circuit SOA

2012 ◽  
Vol 717-720 ◽  
pp. 1045-1048 ◽  
Author(s):  
Woong Je Sung ◽  
B.J. Baliga ◽  
Alex Q. Huang
Keyword(s):  
Power Distribution ◽  
Distribution Systems ◽  
Voltage Drop ◽  
Short Circuit ◽  
Fault Isolation ◽  
Power Distribution Systems ◽  
Trade Off ◽  
Forward Voltage Drop ◽  
Isolation Device ◽  
Safe Operating

This paper aims to introduce a solid-state fault isolation device (FID) for the short circuit protection application in the power distribution systems. The key performance of a FID is to have a low on-state loss and a strong short circuit safe operating area (SCSOA). As a FID, a novel 15kV 4H-SiC field controlled diode (FCD) with a p+buried layer is proposed to provide an improved trade-off between the on-state forward voltage drop and the saturation current. Dynamic response to the fault and the application example of the proposed FCD are described in this paper.

scholarly journals Probability-Based Customizable Modeling and Simulation of Protective Devices in Power Distribution Systems

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 199
Author(s):  
Chengwei Lei ◽  
Weisong Tian
Keyword(s):  
Power Systems ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Current Data ◽  
System Level ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Protective Devices

Fused contactors and thermal magnetic circuit breakers are commonly applied protective devices in power distribution systems to protect the circuits when short-circuit faults occur. A power distribution system may contain various makes and models of protective devices, as a result, customizable simulation models for protective devices are demanded to effectively conduct system-level reliable analyses. To build the models, thermal energy-based data analysis methodologies are first applied to the protective devices’ physical properties, based on the manufacturer’s time/current data sheet. The models are further enhanced by integrating probability tools to simulate uncertainties in real-world application facts, for example, fortuity, variance, and failure rate. The customizable models are expected to aid the system-level reliability analysis, especially for the microgrid power systems.

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