Performance Comparés

In the “Moulin de Solignac” HPP, a gearbox and an asynchronous generator were replaced by a PMGA’s Permanent Magnet Generator (400 kW – 136 rpm). We were given by the owner of HPP recorded data from old and new configuration, for a same position of blades and wicket gates of the double regulated Kaplan turbine.

For a same position of the components responsible for governing Power (Blade/Wicket gates), we can observe a power capicity increase of 20 kW on all the range.

For high loads (400kW), the increase of 20 kW matches with a better efficiency of 5%.

For mid loads (200kW), the increase of 20 kW matches with a better efficiency of 10%.

For low loads (100kW), the increase of 20 kW matches with a better efficiency of 20%.

Efficiency comparison

In order to explain the numbers above, we use the efficiency curve of our generators (perfectly known and determined during conception) and we use efficiency curves of gearbox systems and asynchronous generator given by manufacturers.

The efficiency difference increases when load decreases :

  • In high loads area : a difference of 3 to 4 percentage points
  • in low loads area (25% to 50% of power) : the difference increases and can reach 10 percentage points.