Aiming at the questions encountered in various state estimation algorithms for AC/DC combination system

a new state estimation algorithm is proposed in this paper

which can make AC active power

reactive power and DC equations decoupled fast. In the process of state estimation

AC and DC equations are solved in turn

keeping all high order derivatives of Taylor series for the DC equation. Thus

the Jacobian matrix related to the DC equations can be constant in the iterative process

which decreases the computation burden. On the other hand

it also makes the proposed algorithm have good convergence performance. Basing on the IEEE 14-bus system

a multi-terminal DC/AC combination system is established and simulated. The simulation results show that the algorithm is effective and feasible.