Aspect of voltage stability and reactive power support in active distribution

In this study, the aspects of voltage stability related to voltage control and reactive power support in an active distribution grid are analysed, considering both static and dynamic system constrains. The analysis is carried out based on different international and local utility standards for voltage source converters (VSCs) and distribution. The ability of VSCs to provide reactive power support is explored in a structural way to improve voltage stability as well as power quality. The functional requirements of the VSCs are identified for this purpose in a generalised platform with the assumption of extension of the network automation till the distributed resources level. The step-by-step formulation of voltage stability and reactive power support requirements from system level are translated to VSC level for both static and dynamic system operation, aiming for a better system performance and new energy market scenario. The opportunity of tariff benefit would attract the DG operators as well as the customer for participating in system security through reactive power support and voltage profiling. The main contribution of the study lies in providing a comprehensive guideline for voltage control and reactive support of VSC interfaced DGs in active distribution combining the static and dynamic limitations.