Harmonic and transient state assessment in the time-domain

Power quality simulation is required to provide an evaluation of the adverse phenomena such as transients, harmonics, and voltage sags in a power system, among others. This paper details a methodology to assess adverse power quality effects. In this methodology, the power system is modeled in the continuous-time by an ordinary differential equations set. The equations set are solved through a numerical integration procedure. The methodology is applied to the modified New Zealand test power system including linear and nonlinear loads. The results are validated through a direct comparison of the state response against the actual response obtained from the time-domain power system simulation performed using the SimPowerSystems toolbox of Simulink®. The obtained results indicate that the methodology accurately estimates power quality harmonic and transient state, respectively.