With the rapid development of power electronic power systems, the risk of cascading failures caused by voltage-sensitive problems of power electronic devices has become a problem to be solved. This type of cascading failure is generated by the change in voltage and differs markedly from the conventional form of cascading faults in power systems. In response to the problem, this paper analyzes the characteristics of cascading failures in power electronic-based power systems, introducing the concept of voltage-dominant cascading failures and defining transmission segments of voltage-dominant cascading failures as Voltage Response Events (VREs). By analyzing common features such as initiation conditions, action time, and consequences of VREs occurring in power electronic devices, a model for VREs under sustained voltage variations is established, and the state domain of VREs is determined. In addition, by analyzing the causal and temporal correlations among VREs in different devices, the causal and temporal correlations among VREs are quantified. Finally, a method for searching voltage-dominant cascading failure paths is proposed based on the interrelationships between VREs.