Combined ZVS–ZCS topology for high-current direct current hybrid switches: design aspects and first measurements

Abstract

Power electronic switches have been considered for load switching ever since their invention. This is because semiconductor switches enable fast, arc-less, reliable and maintenancefree switching. The main disadvantages in relation to conventional switches (i.e. circuit breakers), however, are their sensitivity to transients, high on-state losses and the presence of leakage current. The advantages of both types of switches can be exploited by combining the semiconductor and the mechanical switch and thereby their disadvantages, arc formation and regular maintenance, can also be eliminated. For hybrid switches (HSs), both zero voltage switching (ZVS) and zero current switching (ZCS) are frequently used. A new hybrid switching topology has been developed where both ZVS and ZCS techniques are applied to the mechanical switch. The 'symbiosis' between these solid-state switching techniques and a mechanical switch eliminates several of the disadvantages, resulting in a more reliable direct current (DC) HS that requires less maintenance. The first turn-off measurement (up to 5 kA) from a prototype that has been developed for a 3-kV DC grid is presented.

Investigation of DC hybrid circuit breaker based on high-speed switch and arc generator

“…Thereby, the fault current can be broken by DC hybrid circuit breaker long before it reaches the expected maximum level, enhancing the safety and stability of electrical networks. 4,5 Generally, HSS is designed based on the electromagnetic repulsion mechanism with huge forces exerting in extremely short time. 6,7 During the past decades, great efforts have been made to improve the moving speed of the contacts of HSS in order to maintain insulation and withstand the breaking over voltage as fast as possible after the current is commutated.…”

Effect of adding impedance for current balancing on the vacuum arc commutation characteristics of DC microgrid hybrid circuit breakers

“…Therefore, it is necessary to explore the effect of increasing the vacuum arc voltage on the duration of vacuum arc commutation in the case of adding impedance. It can be known from Formula (10) that increasing the vacuum arc voltage is equivalent to increasing the parameter k , and Formula (10) is rewritten as shown in Formula (12), where U arc is the vacuum arc voltage after increasing the voltage and x U is the increasing multiple of the parameter k :…”

Drive circuits for ultra-fast and reliable actuation of Thomson coil actuators used in hybrid AC and DC circuit breakers

“…2). Both simulations and experiments indicate that a capacitor bank charged to a higher voltage drives the moving mass to a higher speed [9][10][11][12][13][14][15][16][17]. However, this is only a reflection of systems starting with more stored energy.…”

“…Most implementations of Thomson coil based FMS [9][10][11][12][13][14][15][16][18][19][20], employ a single pulse circuit, perhaps because of simplicity. Its variations include Circuit 1, 2 and 3 as shown in Fig.…”