Based on the timevarying Fourier coefficient series

a newly developed method—dynamic phasors method is presented and applied to model and analyze VSCHVDC (voltage source converter based HVDC). On the basis of the system switch function model

this approach makes the system simple by neglecting the unimportant higher order components and keeping only those significant components of the Fourier series corresponding to the state variables in the system dynamic equations

so the system dynamic phasors model and equation can be gained. The results show that the dynamic phasors method simulation corresponds to the envelop of the detailed time domain simulation and can reduce the system simulation time greatly. The dynamic phasors method can become the interface of the electromagnetic transient and electromechanical transient models and is applied to the hybrid simulation of power system.