Research and Optimization of CPU Calculation Time Test for Safety Control System of CPR1000 Unit in Nuclear Power Plant

System CPU calculation time is an important index of CPU operation in safety control system of nuclear power plant. Once the CPU runs abnormally, the reactor protection function and special safety function of nuclear power plant will not be implemented normally, which will lead to shutdown and misoperation of equipment in severe cases. Therefore, it is particularly important to study CPU calculation time of CPR1000 unit system of nuclear power plant. Due to the complex operating environment of nuclear power plant, in order to accurately collect the CPU calculation time of the system and analyze it, it is necessary to eliminate the electromagnetic interference and other noises on site to ensure that the collected signals can truly reflect their own characteristics. In this paper, wavelet analysis method is introduced into the system CPU calculation time denoising process, and the calculation time denoising technology is improved by improving threshold function. The comparison of the experimental results of the system CPU calculation time denoising with hard threshold function and soft threshold function shows that the system CPU calculation time data collected after the introduction of wavelet analysis method can not only effectively eliminate noise, but also truly reflect the characteristics of the data itself, providing a new method for the CPU calculation time testing of the safety control system of CPR1000 unit in nuclear power plant.