Abstract
<jats:p>This paper considers forming the daily power load profile of an irrigation pumping station with a variable frequency drive (VFD) using a prescribed water-demand profile. The required network head is defined by an engineering system curve that accounts for the static component and hydraulic losses, and a minimum head constraint at the consumer is imposed. The pump head curve and efficiency at nominal speed are specified in tabular form from passport data and converted to variable-speed operation using similarity laws for rotodynamic pumps. For each time step, the set of admissible drive speeds that satisfies the required flow rate and the head constraint is determined. The operating speed is selected by minimizing power over the admissible set. The power profile is calculated from hydraulic power with efficiency and is compared with constant-speed operation. The method is evaluated by daily energy, specific energy per delivered volume, and peak power at the same daily delivered volume. For a representative two-peak daily irrigation profile, daily energy decreases from 927.44 to 668.63 kWh and specific energy decreases from 0.26727 to 0.19269 kWh/m³ at an unchanged delivered volume of 3470 m³. Peak power decreases from 65.754 to 53.24 kW. The reductions are 27.91% for daily and specific energy and 19.03% for peak power. The approach is recommended for load-profile generation and VFD regime justification for agricultural irrigation pumping stations.</jats:p>