Voltage stability studies in multimachine power systems

In this paper the dynamic voltage stability of multimachine power system is discussed. A new power-flow method, which has no convergence problem near the point of loadability limit is developed and used to trace P-V curves. From the P-V curves the weakest bus of the system is identified and then the multimachine power system is reduced to an equivalent single-machine-load-bus (SMLB) system. Using the equivalent system a method of designing the reactive power compensation and the critical time before which the compensation has to be applied is presented.