Study on Air Arc Simulation of Molded Case Circuit Breaker Using Circuit Model

A molded case circuit breaker (MCCB) is a critical low-voltage switching device widely used to protect electrical circuits from fault currents by interrupting the flow of excessive current. During the switching operation of an MCCB, the movement of the electrode initiates the formation of an electrical arc. This arc is a plasma that is driven into the arc chamber, where its behavior plays a pivotal role in determining the overall effectiveness of the current interruption process. The process of extinguishing the arc, which is crucial for reducing the current to zero, involves increasing the voltage across the arc plasma. As a result, the shape and behavior of the arc become key factors in defining the electrical characteristics of the MCCB during its switching operation. In this study, a detailed simulation approach is employed to model the arc plasma phenomenon within the MCCB. By simulating the arc's behavior, including its shape and movement, the study aims to predict the resulting arc voltage. This prediction is essential for understanding and improving the switching performance of the MCCB, as the arc voltage directly influences the device's ability to effectively interrupt the fault current. To further enhance the accuracy of the simulation, a circuit model is integrated into the analysis. This combined approach allows for the observation of the current limiting effect, which is a crucial performance characteristic of MCCB. The results of the simulation are then validated by comparing them with experimental data obtained from controlled tests. This comparison demonstrates a strong agreement between the simulated and experimental results, confirming the reliability of the simulation model in predicting the behavior of arc plasma and the associated voltage during the switching operation of the MCCB. The findings of this study contribute valuable insights into the optimization of MCCB design and performance, providing a foundation for further improvements in the safety and reliability of low-voltage electrical systems. By accurately predicting the arc behavior and voltage, this research supports the development of MCCB with enhanced current-limiting capabilities, ultimately leading to more robust and efficient protection devices for electrical circuits.