Placement of variable-speed wind power generators in power systems considering steady-state voltage stability

Abstract

This paper investigates the most suitable location to place variable-speed wind generator based wind farms in a power system considering the steady-state voltage stability. The doubly-fed induction generator (DFIG) and the full-converter wind generator (FCWG) based wind generation is considered and the inherent reactive power capability of these generators are accurately represented in the study. Steady-state voltage stability is analysed using QV modal analysis and QV curves. QV modal analysis is used to identify the weak and strong busbars in the test system. Wind power generators with different power outputs are integrated to the power system from weak and strong busbars and the impact of voltage stability is compared using QV stability margins of the busbars. The results demonstrate that adding wind generation from the weak busbars significantly increases the QV stability margin of the weak busbars. However, adding wind generation from strong busbars slightly improve the stability margin of the weak busbars. Therefore, placing wind farms in the weak busbars in a power system is favorable for the overall voltage stability. Furthermore, the results of DFIG and FCWG based wind generation are compared and the higher reactive power capability of the FCWG based wind generation to support the voltage stability is demonstrated.