Time-domain steady-state method of a closed-loop voltage source converter

A voltage source converter (VSC) is one of the most widely used power converter in the power system. In this paper, a time-domain based accelerated steady-state method is proposed to solve for a closed-loop pulse-width modulated (PWM) VSC with dq-frame controllers and is able to account for harmonic interactions between the converter and the rest of the power network, between the ac and dc sides of a VSC, and between converter and its controllers. The proposed time-domain method is based on the modified time-domain shooting methods, where the Jacobian matrix is updated by Quasi-Newton method. This will drastically increase the computation efficiency as it avoids re-evaluating and inverting the Jacobian matrix, whose size is usually very large for a PWM-VSC due to high number of switching times. All the results are shown to be consistent with those obtained by a PSCAD/EMTDC model.