Simulation with controlled Fourier spectrum shifting for efficient computation of power system transients

Simulators of the electromagnetic transients program (EMTP) are widely used for the accurate simulation of transients in electric power networks. EMTP simulations are inefficient in representing low-frequency transients whose Fourier spectrum is concentrated on a narrow bandwidth around the carrier frequency of either 50 Hz or 60 Hz as typically found in AC electric power networks. This is because the carrier frequency component is always tracked even if the main interest is concerned with envelope information. Recently it was proposed to modify the EMTP formulation through the introduction of analytic signals and the shift frequency as a novel simulation parameter such that efficient simulation of both high-frequency and low-frequency transients is made possible. The shift frequency allows one to specify by how much the Fourier spectrum associated with the analytic signal is shifted. In the case study presented in this paper, the added value of this technique is illustrated through the simulation of network energization, transitional steady state, and deenergization