On-load tap changer (OLTC) is the indispensable and frequently operated core component of transformer, which requires high mechanical reliability and stability. During its operation, any mechanical failure may cause serious electrical faults and consequences. As the main arc-extinguishing component of vacuum-type OLTC, the dynamic characteristics of vacuum interrupter (VI) determine whether OLTC can complete the switching. In the current work, the dynamic model of on-load tap changer is established, and experiments are designed to verify its accuracy. Then the dynamic characteristics of OLTC are explored, and especially the vacuum interrupter are focused. The obtained results shows that the VI dynamic characteristics are related to vacuum contact structure. The simulation results can provide valuable information for mechanical system design and optimization of vacuum-type OLTC.

On-load tap changer; multi-body dynamics; vacuum interupter; mechanical characteristics.