A new protection scheme for hybrid cascaded HVDC transmission lines based on cosine similarity algorithm
In order to improve the speed and reliability of DC transmission line protection in hy-brid cascade DC transmission system,a hybrid cascade DC transmission line protection principle based on cosine similarity algorithm was proposed.When the line fault of the hybrid cascade DC transmission system was made,the current and voltage would change,so the voltage and current transient components at the first and last end of the transmission line were used to compare the differences of current and voltage fault components through data standardization and cosine simi-larity algorithm,so as to complete the accurate identification of faults inside and outside the area.PSCAD/EMTDC software was used to build the simulation model of UHV hybrid cascaded DC transmission system,and the feasibility of the protection strategy was verified by Matlab.The simulation results show that when a fault occurs inside and outside the area,the protection prin-ciple can complete the fault identification within 3 ms,and the protection scheme is reliable and fast-moving.When different transition resistors are set in the area,the fault can still be accurate-ly identified,and the protection scheme has a strong ability to withstand the transition resist-ance.
hybrid cascade DC systemcosine similarityfault componentline protectionfail-ure recognition
国家科技期刊平台
NSTL
万方数据
维普
