Time-domain simulation investigates voltage collapse

Fast and slow power system dynamic performance is illustrated with two examples from actual electric utility systems. These examples were chosen to characterize a local reactive power shortage and radial system performance, respectively. In both cases, a critical disturbance is examined. These disturbances result in a load flow that cannot be solved. Studies were performed with the Extended Term Dynamics module of PTI's Power System Simulation (PSS/E) program.<<ETX>>