IEC medium-voltage circuit-breaker interrupting ratings-unstated short-circuit considerations

2000 ◽  
Vol 36 (3) ◽  
pp. 884-892 ◽  
Author(s):  
R.E. Cosse ◽  
T.G. Hazel ◽  
G. Thomasset
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Medium Voltage

scholarly journals Circuit Breakers in Low- and Medium-Voltage DC Microgrids for Protection against Short-Circuit Electrical Faults: Evolution and Future Challenges

2021 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Bayron Perea-Mena ◽  
Jaime A. Valencia-Velasquez ◽  
Jesús M. López-Lezama ◽  
Juan B. Cano-Quintero ◽  
Nicolás Muñoz-Galeano
Keyword(s):  
Low Voltage ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Circuit Breakers ◽  
Medium Voltage ◽  
Advantages And Disadvantages ◽  
General Terms ◽  
Future Challenges ◽  
Electrical Faults ◽  
Medium Voltage Dc

This paper deals with circuit breakers (CBs) used in direct current microgrids (DCMGs) for protection against electrical faults, focusing on their evolution and future challenges in low voltage (<1.5 kV) and medium voltage (between 1.5 kV and 20 kV). In recent years, proposals for new circuit-breaker features have grown. Therefore, a review on the evolution of circuit breakers for DCMGs is of utmost importance. In general terms, this paper presents a review concerning the evolution of circuit breakers used in DCMGs, focusing on fuses, mechanical circuit breakers (MCBs), solid-state circuit breakers (SSCBs), and hybrid circuit breakers (HCBs). Their evolution is presented highlighting the advantages and disadvantages of each device. It was found that although modern circuit breakers have begun to be commercially available, many of them are still under development; consequently, some traditional fuses and MCBs are still common in DCMGs, but under certain restrictions or limitations. Future challenges that would allow a successful and adequate implementation of circuit breakers in DCMGs are also presented.

scholarly journals Modeling Operation of Liquid Metal Fuses When Breaking Overcurrents

2020 ◽  
Vol 178 ◽  
pp. 01060
Author(s):  
A V Kuznetsov ◽  
D S Aleksandrov ◽  
Y P Yurenkov
Keyword(s):  
Liquid Metal ◽  
Short Circuit ◽  
Time Moment ◽  
Circuit Breaker ◽  
Reference Points ◽  
Joint Operation ◽  
Pilot Studies ◽  
In Series ◽  
Current Limiter ◽  
Temperature Melting

This paper shows that successful switching of extremely high short-circuit currents I> 50 kA can be achieved by joint operation of a liquid-metal self-resetting current limiter and a circuit breaker connected in series. The type NFU-225 device from Mitsubishi was taken as an example. The time-current characteristic of joint operation of a liquid-metal self-resetting current-limiting device and a circuit breaker was compiled. However, further in the article physical processes occurring in a liquid-metal self-resetting current limiter with a complete transformation of fusible unit are considered. The result of work is modelling of operation of liquid-metal fuses when overcurrents are switched off based on the pilot studies obtained by the Japanese scientists. It is proposed to simulate the break process not at every time moment, but at specific time moments (reference points). At other time moments, current and voltage should be considered as approximately linearly changing characteristics. The work of current limiter can be represented by three stages: the pre-arc, the main arc and the final arc. If the current density is less than 1000 A/mm2, then the pre-arc operation stage of the current limiter includes the following sections for heating the fusible unit: primary heating to the melting temperature; melting and its transition to liquid state; secondary heating to evaporation temperature; evaporation of fusible unit.

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.

Research of Large-Scale Offshore Wind Farm Collection System Short Circuit Equivalent Network

2013 ◽  
Vol 448-453 ◽  
pp. 1732-1737
Author(s):  
Liu Bin ◽  
Hong Wei Cui ◽  
Li Xu ◽  
Kun Wang ◽  
Zhu Zhan ◽  
...  
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Short Circuit ◽  
Short Circuit Current ◽  
System Optimization ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Collection System ◽  
Medium Voltage ◽  
The Impact

This paper analyses the characteristics of large-scale offshore wind farm collection network and the impact of the medium voltage collection system optimization,while from the electrical technology point,it proposes the short circuit current of the collection network computational model and algorithms,based on the principle of equivalent circuit.Taking a wind power coolection system planned for a certain offshore wind farm planning for example, the validity of the model and algorithm is verified.

Dependence of Short Circuit Breaking Current on its Minimum Arcing Times of a Fast Vacuum Circuit Breaker

2021 ◽  
Author(s):  
Chen Guan ◽  
Xiaofei Yao ◽  
Weidong Wang ◽  
Ran Zhang ◽  
Luyang Zhang ◽  
...  
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Vacuum Circuit Breaker

Protection Coordination of 33/11 kV Power Distribution Substation in Iraq

2021 ◽  
Vol 39 (5A) ◽  
pp. 723-737
Author(s):  
Yamur M. Obied ◽  
Thamir M. Abdul Wahhab
Keyword(s):  
Time Delay ◽  
Power System ◽  
Power Distribution ◽  
Software Package ◽  
Short Circuit ◽  
Distribution Network ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Earth Fault ◽  
Current Characteristics

The coordination between protective devices is the process of determining the most appropriate timing of power interruption during abnormal conditions in the power system. The aim of this work is to coordinate the protection of the 33/11 kV power distribution substation in Iraq using the CYME 7.1 software package. In this paper overcurrent and earth fault relays are simulated in two cases, with time delay setting and instantaneous setting, to obtain the Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay of Al-Karama substation (2×31.5 MVA, 33/11 kV) in Babil distribution network. The short circuit current at each CB is calculated and accordingly, the protection coordination for Al-Karama substation has been simulated. The TCC curves have been obtained in two cases for overcurrent and earth fault relays; in a case with time delay setting and in the case with the instantaneous setting. The setting takes into consideration the short circuit current at the furthest point of the longest outgoing feeder and the shortest outgoing feeder.

Sign in / Sign up

Export Citation Format

Share Document