DC vacuum arc in a nonuniform axisymmetric magnetic field

Abstract

An experimental investigation is performed of the characteristics of DC vacuum arc during the opening of contacts in an axisymmetric magnetic field with different ratios between the axial and radial components of magnetic field induction. A study is made of the main features of the dynamics of plasma glow in the contact gap during the stable and unstable stages of arcing until the arc extinction in the current range of 50 to 150 A with the voltage limited at the instant of breaking of current to a level of 8 kV. Possible mechanisms of disturbance of the vacuum arc stability in an axisymmetric magnetic field are discussed.

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

“…t N 0 , t N 1 , and t N 2 all increase linearly with N , which is consistent with the rule shown in Formula (9). t N 2 − t N 0 increases linearly with N , and t N 1 − t N 0 remains basically unchanged with N , which is consistent with the rule shown in Formula (15). From the curves of t N 2 − t N 0 and t N 1 − t N 0 under different N , it can be seen that the effect of added resistance on the duration of vacuum arc commutation increases linearly with N , and the effect of added inductance on the duration of the vacuum arc commutation is independent of N .…”

“…and A 0 = A when R a = 0, and according to Formula (9), the following relation can be obtained for Formula (15):…”

“…As shown in Formula (15), the increased duration of vacuum arc commutation due to adding resistance can be divided into three parts. (NL m + L e )(A − A 0 ) is the increased duration of vacuum arc commutation due to adding resistance, and it is obvious that it increases linearly with N .…”

“…Due to fewer vacuum arc voltage changes during vacuum arc commutation , facilitation of the theoretical calculation of the arc voltage is simplified to a constant value during the entire vacuum arc commutation. For example, as shown in Fig.…”

Research on Vacuum Arc Commutation Characteristics of a Natural-Commutate Hybrid DC Circuit Breaker

“…R represents the approximate on-state resistance of the FPEDs. Us0 represents the approximate on-state voltage of the SS when the Is is zero: As shown in Figure 3, because the change in the vacuum arc voltage is relatively small during the vacuum arc commutation [24], U arc-avg can be taken as the vacuum arc voltage value, and U arc-avg is the average value of the maximum value U arc-max and the minimum value U arc-min of the vacuum arc voltage. According to Formula (5), the model shown in Figure 4a can be rewritten as shown in Figure 4b.…”