The high voltage alternating current/direct current (HVAC/DC) system has a complex structure and a wide variety of components

so the reliability assessment using traditional methods bears huge computational burden. To improve the efficiency of HVAC/DC system reliability assessment

a HVAC/DC system reliability evaluation method based on an improved point estimation method is proposed in this paper. The proposed method analyzes the structure of various components of a typical HVAC/DC system and leverages the Dirac function to smooth the involved discrete random variables

so that the discrete component status can be generally tackled in common with the load

wind power and other continuous random variables using the point estimation method. On top of that

a non-linear program of minimum load shedding is embedded into the point estimation method to efficiently summarize kinds of reliability indices via finite-time optimal power flow calculation. Finally

a modified HVAC/DC test system based on the IEEE 14 system is utilized to demonstrate the usability and limitations of the proposed method. The results show that the proposed method can effectively reduce the calculation amount of HVAC/DC system reliability evaluation under certain conditions

and has good accuracy and efficiency performance.