Calculation methodology for determining the number of simultaneous self-starting pumping units

The paper considers the methodology of calculating the number of self-starting pump units depending on the network voltage landing and the basic calculation dependencies of the process of selfstarting of electric motors supplied from three-phase three-winding transformer; the substitution scheme for one phase of the circuit is made. Technical solutions for upgrading pump units, which allow applying the selfstart mode at ameliorative pumping stations, are proposed.