Operation Analysis and Improvement of Impulse Current Test on High-Power DC Test Platform With SVC System

The international thermonuclear experimental reactor poloidal field converter unit is comprised of four converter bridges, dc reactors, dc switches, etc., and most are nonstandard. To evaluate the performance of these equipments, a high-power dc test platform has been built to carry out the steady-state current test and impulse current test. The latter is significant to verify the fault suppression capability of products. The dc test platform can output the rated 400-kA impulse current. The principle design and structure of the dc test platform is introduced in this paper. The transient large current in impulse current test could cause huge impact reactive power and grid voltage sag. The impact is analyzed by theoretical calculation and simulation. A static var compensator system is added to suppress the transient effects of the reactive power. A predictive reactive power control strategy is proposed to improve the dynamic response. The comparisons with the traditional control demonstrate that the proposed control is effective in compensating impact reactive power and it also performs well on inhibiting the grid voltage sag.