Back-to-back Starting of Large-capacity Condenser with Virtual Synchronous Generator

This paper presents a modified back-to-back starting (M-BBS) method with virtual synchronous generator (VSG) technology for starting a large-capacity synchronous condenser (SC). An M-BBS system is built first, including the cascaded H-bridge converter (CHB) controlled as a VSG, and an SC. The control structure containing a VSG model, a speed controller, and a current feed-forward controller, is then established to access of the influence of critical factors, such as the field excitation and the initial relative angle between the machines, on the starting process. Also, a principle how to start a large-capacity SC by regulating the mechanical torque and the damping torque is proposed. Finally, the simulation results are presented validating the theoretical analyses.