Power system transient and harmonic studies using wavelet transform

This paper presents the application of wavelet transforms in power system transient and harmonic analyses. Based on the discrete time domain approximation, the system components such as resistors, inductors and capacitor are modeled respectively in the discrete wavelet domain for the purpose of transient and steady state analyses. Since the power system is described by a set of ordinary differential equations, an initial value of the state variable is considered for the transient analysis, while a periodic condition is applied to the state variable for the steady state analysis. The wavelet domain impedance is set up, and the equivalent circuit is thus built for system simulation. This method can be implemented by any kind of orthogonal wavelet transform. Numerical results from an arc furnace system are also presented for the transient, harmonic and time-frequency analyses