Irrigation system

Farmers irrigate their fields during periods of dry weather to ensure normal growth. As the irrigators are driven by the water flow, constant pressure is essential for even water distribution over the fields.
The irrigation system contains a frequency converter and eight parallel submersible pumps. The submersible pumps feed water to the irrigators, which are mounted on lightweight carriages. The carriages are first pulled across a field, then slowly dragged back by the water supply hoses rewinding onto large reels. As the reels are powered by flowing water, the pressure has to be constant to ensure an even water distribution.


Irrigation system

The speed of one pump motor is controlled by an AC drive, which also switches on the fixed-speed pumps as required. Another fixed-speed pump is started and the speed of the frequency converter driven pump is correspondingly reduced when the pressure in the pipeline falls below a preset limit. Conversely, the pumps are stopped sequentally when the pressure exceeds an upper limit.

Problems Solved

• Pressure surges that stress the equipment mechanically
  
• High labour cost
  
• Uneven water distribution

• Motors: 7x55 kW, 75 kW, 2500 to 3200 rpm, 380 V
  
• Frequency Converter: 133 kVA, 380 V
  
• Pressure regulation
  
• Automatic pump control

• Even water distribution due to accurate flow control
  
• Reduced energy consumption through optimum flow control
  
• Lower maintenance costs as pressure schocks are eliminated
  
• Lower labour costs due to automatic control