Analytical presentation of mechanical characteristics of main line pumps with frequency-regulated drives

In recent years frequency-regulated drives of main line pumps have been widely used on oil booster station. One of the problems faced by developers of regulated drives is absence of analytical expressions describing mechanical characteristic of pump in particular operating conditions. The paper deals with equations of mechanical characteristic workable range of booster station main line pumps when using frequency-regulated drive. To obtain this characteristic we study how mode of oil delivery through main pipelines influences the resisting moment of frequency-regulated main line pump. The paper presents expression for minimum permissible frequency of operating range of speed of main line pumps. We obtained analytical expressions for mechanical characteristic of main line pump in function of two variables: rotational speed and pipeline productivity, and in function of one variable - rotational speed.