Transient sinusoidal signal sequence component access method of electric power system

The invention relates to a transient sinusoidal signal sequence component access method of an electric power system, which comprises the following steps: inputting an acquired input signal into a sine approximation processor to approximate, calculating the cosine function of the input signal according to a function after approximation, and then calculating the positive sequence component, the negative sequence component and the zero sequence component of a sinusoidal signal according to the acquired input signal and the calculated cosine function of the input signal. The method obtains the sequence components of the transient sinusoidal signal by adopting the sine approximation processor to work out the cosine function of the transient sinusoidal signal, meets the nature of the amplitude and the initial phase of the transient sinusoidal signal of changing with the time, can accurately acquire the sequence components of the rapidly changed transient sinusoidal signal and lays accurate, timely and reliable foundation for electric power engineering based on the transient sequence components.