High frequency eigenanalysis of HVDC and FACTS assisted power systems

Conventional transient stability or eigenvalue programs can not be used for investigating high frequency control interaction phenomena on HVDC and/or FACTS assisted power systems. In these programs the network is modeled by algebraic equations and therefore only the fundamental frequency phasor behavior of the system is represented. Higher frequency interactions are not captured by this type of analysis and completely fail to help engineers to correctly design power electronics based controllers to avoid high frequency unstable situations. This paper presents a comprehensive approach for investigating the high frequency dynamic response of both HVDC and FACTS controllers. The adopted method is bared on the application of generalized switching functions. The second harmonic instability problem in HVDC systems is investigated using the proposed methodology.