On the basis of the dynamical equivalent data of East China power system in big load mode in summer of 2013

a research model of AC/DC transmission system in East China is built in the electro-magnetic transient program. The multi-infeed DC transmission system identically based as the actual project is established

realizing the combination of NARI Group Corporation'

XJ Group Corporation' and ABB Group's various detailed technical route models of high-voltage direct current (HVDC) control and protection. The commutation failure prediction methods and the low voltage current limiting parameters of the six HVDC projects in East China are at present compared and analyzed and the parameter differences among them are given. The effects on preventing the commutation failure of different methods

such as optimizing commutation failure parameters

increasing the constant extinction area

increasing the rated extinction angle

etc.

are researched. Finally

according to research on the low voltage current limiting parameters and limits for the instantaneous current

the recovery strategy after HVDC commutation failure is presented. The research results are able to provide technical reference to the operation of the HVDC system. This work is supported by State Grid Corporation of China

Major Projects on Planning and Operation Control of Large Scale Grid (No. SGCC-MPLG001-2012).