The ongoing development of renewable energy and microgrid technologies has gradually transformed the conventional energy infrastructure into a modernized system with more distributed generation and localized energy storage options. Compared with power grids utilizing synchronous generation, inverter-based networks cannot physically provide large amounts of inertia. Therefore, more advanced, and extensive studies regarding stability considerations are required for such systems. Appropriate analytical methods are needed for the voltage stability analysis of renewable-dominated power systems, which incorporate many inverters and distributed energy sources. Microgrid voltage stability is being challenged as the power output of renewable energy generation is not as stable as the traditional generation used in the main grid. Therefore, the choice of voltage stability analysis techniques plays an important role in the stable operation of the microgrid. This thesis comprehensively studies static voltage stability analyses of islanded microgrids with high levels of renewable energy penetration. Firstly, a series of generalized evaluation schemes and improvement methods relating to the voltage stability of power systems integrated with various distributed energy resources are discussed. This study presents guidelines for voltage stability analysis and instability mitigation methods for modern renewable-rich power systems. Then, four dominant VSI techniques for microgrids are studied and compared in this paper. An islanded microgrid system is modelled based on the IEEE-14-bus system in PSCAD. The model evaluates the stability results analyzed by different voltage stability indices (VSIs). Four simulation scenarios are applied in this thesis, including changing the output power of distributed generations (DGs) and the connection position of the DGs. The advantages and disadvantages of each technique are discussed based on the simulation results. A ranking of bus voltage stability is obtained based on the simulation and the VSI calculation. Finally, a novel static voltage stability analysis technique is proposed.