Frequency Stabilisation in Multi Area System Using HVDC Link

When an AC power system is subjected to sudden load changes, system frequency will be considerably disturbed and becomes oscillatory. This is predominant in an interconnected power system. In this paper a new controller is designed to regulate the tie-line power regulation through HVDC link in parallel with the existing AC-AC link for stabilizing the frequency oscillation of AC System. The technique of overlapping decomposition and eigenvalue assignment are applied for the design of power modulation controller. The linear model of AC-DC link is developed and the system responses to various load changes are studied with the help of Mat-Lab simulation. The study shows that the proposed controller is not only effective in damping out the frequency oscillation but is also capable of eliminating the transient frequency swing caused by large load distribution.