derivation calculus meaning in English

求导演算

In digital relay , the percentage of noise will increase rapidly with the increase of sampling rate when derivation calculus is substituted by sampled difference term . to solve this problem , a new method using fragment function integrated with the least square algorithm is proposed in this paper . the influence of white noise is greatly reduced and the accuracy of the dead angle calculation is nicely improved after adopting the new method
在数字式保护中，如果用差分代替求导将导致噪声的百分比误差随着采样频率的提高而剧增，本文对此进行了分析并提出了用分段样条函数最小二乘法来计算电流波形的导数值，以便在提高采样率的同时降低噪声误差的影响，并将其应用于基于32位浮点dsp的新型变压器保护装置。