AbstractVoltage stability analysis always involves a large number of devices with various dynamic characteristics in power system. For properly capturing static and dynamic behaviors providing insights into characteristics of the voltage stability of the system, different system models are established for different time‐scale studies. In this paper, relevant system models are discussed taking into account load characteristics. Based on these models, different approaches such as static analysis, time‐domain simulation and quasi‐steady state (QSS) approximation are implemented into a simulation program, which is used as a comprehensive tool for analyzing voltage stability. By complementary use of these approaches with the simulation program, voltage collapse stresses of the system under a critical operating condition can be analysed in steady state, and impacts of special events on the voltage stability can also be simulated with time‐domain simulations. For time‐domain simulations, a full system model and a QSS approximation can be adopted for capturing different forms of instability mechanisms. A test system is used to demonstrate the feasibility and effectiveness of the approaches implemented. Copyright © 2006 John Wiley & Sons, Ltd.