Wind farm optimum efficiency by voltage control

The basic idea of improving both the power factor and the efficiency of induction motors at partial or light load reducing the supply voltage was patented by F. Nola, in the late 70's of the last century. This energy saving and power factor improvement strategy work better with small power (less efficient) motor and long periods of time with partial or light load under 25-30% of the rated power. These improvements can be applied to the induction generators (induction machines performing as generators), were long periods of low wind speed and low level of generated power are very common. In fact, this technique is more suitable for induction generators than for motors. The soft-starter used to soften the connection transients can be used to supply the wind farm induction generators at reduced voltage during low wind speed periods. This way, more power and reactive power will be available to be injected in the transmission and distribution network at no additional cost.