Transfer Characteristics of DC Voltage Divider and Its Influence on Traveling Wave Protection

Starting from the transfer characteristics of the DC voltage divider, an equivalent circuit model of each part of the DC voltage divider is constructed. The transfer function of the DC voltage divider is derived at first. Then, its step response dynamic performance is analyzed. Based on PSCAD/EMTDC platform, a UHVDC electromagnetic transient simulation model is constructed. Furthermore, the influence of the transmission characteristics of the DC voltage divider on voltage traveling wave protection is simulated. It shows that when an type I voltage divider is used, the amplitude of the traveling wave criterion of the secondary side of the voltage divider after a fault is reduced, but the protection can still operate correctly; When a type II voltage divider is used, the amplitude of the traveling wave criterion on the secondary side of the voltage divider increases after the fault, and the waveform distortion is severe. At the same time, traveling wave protection responds more faster than type I voltage divider.