Contact Pressure Calculation Based on Vacuum Contact Materials and Operating Conditions

Pressure of vacuum circuit breaker contacts should meet the requirements of contact resistance, and inhibit contact bounce when short-circuit current is flowing. However, the value of contact pressure is often obtained empirically. This paper analyzes the worst electrical contact conditions based on the contact resistance of the electrical contact surfaces, and propose a method to calculate the contact pressure based on contact material, radius and short-time current withstand, which is based on the melting of the conductive spots. Finally, hrough the comparison of several sets of working conditions, it is verified that the calculation method is effective.