An efficient method of simulating the detailed electromechanical response of industrial power systems

A new method is presented for simulating the large-disturbance, electromechanical response of mine and other industrial power systems. With this method, detailed waveforms that include the transient components of machine currents and bus voltages can be obtained rapidly. This approach may be a useful supplement to traditional steady-state analysis techniques when considering circuit breaker requirements in light of a variety of system transients including the following: starting of large motors or groups of motors, reclosure of motors following temporary isolation or during bus transfers, and rapid changes in the mechanical loading of motors. The short simulation times associated with this method are achieved by modeling the power system with line charging capacitance neglected. This eliminates high frequency modes, which often lead to long computation times in other detailed simulations, but retains the machine stator transients that affect significantly the instantaneous currents and voltages throughout the system. With shunt capacitance neglected, however, the system model is represented by a set of differential-algebraic equations (DAEs). The crux of the new method is a systematic procedure for establishing a readily simulated state-space model from these DAEs.