In allusion to the high content of 5-, 7-, 11- and 13-order harmonics in the AC system of VSC-HVDC. A kind of control method is adopted by using series connection of modified repetitive controller and PI regulator, which has only half of the control period in traditional repetitive controller. Besides, it has smaller steady state errors and can achieve the function of eliminating the odd harmonics largely. A VSC-HVDC system of two terminals was built in PSCAD/EMTDC, through the simulation and analyses to the harmonic contents of the AC current in the side of converter 1 and 2 without repetitive control added, with traditional repetitive control added and the modified one respectively. The result validates that the modified repetitive control has a better function of suppressing the harmonics.
