Loss sampling data processing method based on third-order spline interpolation method

The invention discloses a loss sampling data processing method based on the third-order spline interpolation method, which comprises the following steps: the communication situation of a digital protective device is detected in real time, if the frame loss or frame error occurs, the status bit of the corresponding loss sampling data is marked invalid; after the communication state recovers, if thenumber of lost sampling points is not more than the number of the already set preset lost sampling points which is allowed to be evaluated, the waveform fitting is carried out by using a third-orderspline function on the basis of at least three effective sampling data before a loss data segment and at least three effective sampling data after the loss data segment, then the approximate value ofthe loss sampling data is evaluated in the interpolation method, and the corresponding state of the loss sampling data is marked estimated; if the number of lost sampling points is more than the number of the already set lost s