Dear all,

I want to design a photovoltaic water pumping system with PV nominal power of 4000 W. I want to evaluate my code with Grundfos 25 SQF-7 pump. This pump has maximum nominal power of 1.4 kW, so the system needs three of them connected in parallel. The H-Q-P curves of this pump is available by the manufacturer (attached).

1- At constant head of H=50m, each pump needs 330 W to run, so none of them would work at 8 AM , is it correct? What strategy would you take to make use of power at early morning (low irradiations) or late afternoon? Would be possible to use a control system to direct the whole power at 8 AM (900 W) for only one pump to make one pump work? And to divide power equally to the other three pumps at higher irradiations? Can you suggest any optimization technique?

2- At constant head of H=50m, each pump needs 330 W to run, so none of them would work at 8 AM (with 900 W available power) , is it correct? What strategy would you take to make use of low powers at early morning (low irradiations) or late afternoon? Would it be possible to use a control system to direct the whole power at 8 AM (900 W) for only one pump to make at least one pump work? And to divide power equally to the other two pumps at higher irradiations (at noon, for example)? Is there any optimization technique for how to control the produced power and how to divide them between the pumps?

Best,

Misagh