HVDC Breaker Test Bench Based on a Power Converter Using Cascaded H-bridge Cells

This paper presents a new type of test bench for HVDC breakers consisting of a power converter based on multiple cascaded H-bridge cells and a small-sized inductor which has the capability to achieve high current controllability by means of phase-shifted pulse-width-modulated (PSPWM) signal applied to the converter. As a result, the test bench can generate high current gradients to simulate fault conditions and the following current-limiting behavior of breakers. In addition, a spark-gap switch can be removed from the system resulting in higher reliability and longer lifetime. The validity of the test bench presented in this paper is verified by experiments using a down-scaled model based on nine cascaded H-bridge cells with an equivalent switching frequency of 92.5 kHz.