Determination of DC Short-Circuit Currents of MMC-HVDC Converters for DC Circuit Breaker Dimensioning

2015 ◽  
Author(s):  
A. Wasserrab ◽  
G. Balzer
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Dc Circuit Breaker ◽  
Short Circuit Currents

scholarly journals Capacitor Commutation Method for MVDC Hybrid Circuit Breakers

Designs ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 28
Author(s):  
Hyosung Kim
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Reverse Current ◽  
Resonant Circuit ◽  
Power Circuit ◽  
Power Sources ◽  
Semiconductor Switch ◽  
Current Commutation ◽  
Dc Circuit Breaker ◽  
Hybrid Circuit

The medium voltage DC (MVDC) type system can connect multiple terminals to a common MVDC bus, so it is possible to connect several renewable DC power sources to the common MVDC bus, but a DC circuit breaker is needed to isolate short circuit accidents that may occur in the MVDC bus. For this purpose, the concept of a hybrid DC circuit breaker that takes advantage of a low conduction loss contact type switch and an arcless-breaking semiconductor switch has been proposed. During break the hybrid switch, a dedicated current commutation device is required to temporarily bypass the load current flowing through the main switch into a semiconductor switch branch. Existing current commutation methods include a proactive method and a reverse current injection method by a LC (Inductor-capacitor) resonant circuit. This paper proposes a power circuit of a new MVDC hybrid circuit breaker using a low withstanding voltage capacitor branch for commutation and a sequence controller according to it, and verifies its operation through an experiment.

scholarly journals Development of a Method and Algorithm for Inhibiting an Automatic Transfer Switch of the Circuit Breaker for a Sustained Short-Circuit

2020 ◽  
Vol 220 ◽  
pp. 01011
Author(s):  
Igor Nikolaevich Fomin ◽  
Roman Pavlovich Belikov ◽  
Tatyana Anatolyevna Kudinova ◽  
Nailya Kamilevna Miftakhova
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Electrical Equipment ◽  
Ring Network ◽  
Circuit Breakers ◽  
Emergency Situations ◽  
Short Circuit Currents

Circuit breakers with automatic transfer switches (ATS) are designed in such a way that when the voltage disappears during a short-circuit (SC) in the ring network line, the ATS device is triggered. At the same time, its switch is turned on at short-circuit, then it is turned off with acceleration. Even a shortterm switching on of the automatic transfer switch for a sustained short-circuit leads to emergency situations [1,2]. The electrical equipment of the ring network spare line is exposed to high emergency short-circuit currents, and the consumers powered by the spare transformer are turned off. It is possible to minimize and eliminate the damages caused by the above mentioned cases by inhibiting the switching on of the circuitbreaker of the automatic transfer switch.

SWITCHING AND LIGHTNING OVERVOLTAGES AND THE REQUIRED WITHSTAND VOLTAGE BETWEEEN THE OPEN CONTACTS OF 245 KV CIRCUIT BREAKERS

2016 ◽  
Vol 63 (0) ◽  
pp. 43-60 ◽  
Author(s):  
Janusz BANDEL ◽  
Artur HEJDUK ◽  
Andrzej DZIERŻYŃSKI ◽  
Piotr KORYCKI ◽  
Henryk SIBILSKI
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Dielectric Strength ◽  
Electrical Insulation ◽  
Power Engineering ◽  
Circuit Breakers ◽  
Short Circuit Currents ◽  
Very High ◽  
Single Break

This paper deals with the surges generated in the network during switching operations and lightning surges. The level of both kinds of surge was compared with the required dielectric strength between the open contacts of 245 kV circuit breakers. Overvoltages greater than the electrical withstand voltage of the circuit breaker can cause arc ignition between the circuit breaker’s open contacts and power engineering service s have reported such cases. The results of such failures can be very serious. This is a problem especially for single-break circuit breakers, in which the stresses on the electrical insulation between the open contacts of the breaker are very high. A method for selecting lightning arresters to lower the overvoltages is proposed. The switching of short-circuit currents by a circuit breaker may cause a weakening of the circuit breaker chamber’s insulation and reduce its electrical withstand and durability.

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