Arc Parameters and Fault Impedance effect on the Gradient of Arc Current and Rate of Rise of Recovery Voltage in HVDC Circuit Breaker Using Mayr Arc Model.

The gradient of Arc Current (di/dt) and rate of rise of recovery voltage (RRRV) are used to study the capability of circuit breaker (CB) to interrupt different faults. The current interruption mechanism in high voltage direct current (HVDC) CB is complicated and needs an auxiliary circuit to generate current zero crossing. Mayr Arc Model is used to simulate the arc current interruption process. The effects of arc model parameters, arc time constant (τ) and cooling power (P), on di/dt and RRRV are presented in this work. It is found that the lower di/dt will appear at higher Arc time constant and lower cooling power values, but with limits. Contrary to di/dt, RRRV has lower values at low arc time constant values and high cooling power values, but Mayr arc model parameters have greater effect on di/dt than RRRV. This paper also addresses the effect of three types of fault impedance (resistive, inductive and capacitive) on di/dt and RRRV. A comparison is carried out for these fault impedances and shows good performance for capacitive impedance.