Objectives  Pulsed load has a considerable effect on the power quality and stability of a system. The solutions are different due to the different operation characteristics of pulsed load. To this end, the working characteristics of a diesel generating set under pulsed load in a survey ship are researched.

  Methods  Load which changes little in average power is the research object of this paper, and using the inherent mechanical energy storage of diesel generators to stabilize power fluctuation is proposed. Certain factors which influence the dynamic performance of a diesel generating set are analyzed and the stability of change and restoration of speed are attained. As such, the engineering summary of smooth power fluctuations in diesel generating sets is concluded. Based on the actual working conditions of a radar in a survey ship, the capacity and performance of diesel generating sets are calculated according to the formulas.

  Results  This research shows that in the worst working conditions in which the load suddenly increases and fluctuates, the speed characteristics and change of the designed generators can meet the requirements.

  Conclusions  The results of this research have guiding significance for the preliminary estimation of diesel generating sets under pulsed load.