Placement of supplementary controllers for multiple HVDC systems

With the development of multiple HVDC system, the design of supplementary controllers for HVDC systems used to damp low frequency oscillation become more flexible and complex. The controller´s performance is bound up with the location of supplementary controller in multiple HVDC systems. Based on TLS-ESPRIT identification algorithm, MHCF (Multiple HVDC Control Factor) is proposed to access the controllability of each HVDC systems on the main oscillation mode in this paper. HVDC systems with high value of MHCF have better performance in damping the oscillation. Sichuan Power Grid is taken as example to illustrate the veracity of the method using MHCF to select the optimal location of HVDC supplementary controller in multiple HVDC systems.