The online economic operation calculation of power systems urgently needs a linearized dynamic optimal power flow model which can get the complete scheduling information quickly. Based on the system incidence matrix

the nodal power balance equations are decoupled into two parts

i. e. power flow and loss flow of lines. To obtain the linearized dynamic optimal power flow model

which can simultaneously get the voltage amplitude and the reactive power of the lines

the loss flow is firstly substituted with its equivalent and the trigonometric functions within the equations are eliminated

then the remaining nonlinear terms are linearized by the Taylor series method. The model is solved by the simplified dual interior point method. To further improve the accuracy of the proposed model

the datum point information required by the Taylor series method is constantly updated in the iterative process. The test results of IEEE 30-node

IEEE 118-node

IEEE 300-node power systems and the 117-node equivalent system of a city verify that the proposed model can obtain more complete scheduling information while keep high accuracy and computational efficiency.