Abstract
High-speed circuit breakers (HSCB) used in DC circuits are one of the basic elements of overload, short-circuit and electric shock protection. Such breakers are used in transport (trams, trolleybuses, subways and railways) in electric power supply facilities and in vehicles. The performance and capability of limiting the current depend on the HSCB design and solutions applied in it. The circuit parameters, particularly its inductance also affect the performance. Additionally, each DC breaking in the RL circuit is accompanied by overvoltages whose level depends on the circuit parameters and breaker design. The paper discussed the process of direct current breaking by magnetic blowout high-speed circuit breakers and factors that affect the HSCB performance, i. e. opening time and arcing time. The influence of the circuit parameters and HSCB design on the value of arc voltage is outlined. The results of laboratory tests of 4 types of high-speed circuit breakers produced in Europe are presented. The test results were used to analyze the effect of current changes in the short circuit on the time of current breaking and the value of switching overvoltages – arc voltage. The results of simulation of the short-circuit breaking in the RL DC circuit made at the rate-of-rise of current in the circuit are presented. Based on the tests and simulations, the current breaking times, values of arc voltage generated in this process and arc energy that is acquired and dissipated by the arc chamber are determined. The objective of the tests and simulations was to answer the question whether it is possible to turn off direct current quickly without generating high arc voltage values – overvoltages in the circuit and how di/dt changes should be formed by a high-speed circuit breaker to achieve the shortest possible time with the lowest possible arc voltage and its lowest energy
Highlights
High-speed circuit breakers (HSCB) used in DC circuits are one of the basic elements of overload, short-circuit and electric shock protection. They appear in transport, in electric power supply facilities and in vehicles. They are used in energy storage, industrial processes and wherever there is a necessity to switch off large DC current values and/or a voltage higher than 1 kV DC is used
High-speed circuit breakers are installed in traction substations and field coupling as fixed breakers as well as tramways, traction vehicles, locomotives and metro carriages as vehicle breakers
Analyzing the results of the laboratory tests – Fig. 6, 7 and data from Table 1, it can be concluded that circuit breakers A and B breaking time was similar
Summary
High-speed circuit breakers (HSCB) used in DC circuits are one of the basic elements of overload, short-circuit and electric shock protection. They appear in transport (trams, trolleybuses, subways and railways), in electric power supply facilities and in vehicles. High-speed circuit breakers are installed in traction substations and field coupling as fixed breakers as well as tramways, traction vehicles, locomotives and metro carriages as vehicle breakers They intentionally break operating currents, while they automatically break overload and short-circuit currents. Due to the constant growth in the power of installed traction devices and the necessity to increase the stiffness of power supplies, the short-circuit current values increase. Each short circuit in the DC system affects the power system [3], which is an additional reason for the necessity of swift short-circuit current breaking
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
