Inverters which are driving variable torque applications such as fan or pump are very often running at partial load. From the drive system point of view this leads to less efficiency operation of the motor due to increased ratio of so called excitation current that the inverter is generating.
Mitsubishi Electric inverters have a unique control algorithm that allows the inverter to continuously adjusts the excitation current in an intelligent way to achieve an optimum level.
This provides the highest possible motor efficiency. With a small load torque, a substantial energy saving can be achieved.
For example, at 4% motor load torque for a general-purpose motor, the motor efficiency under Optimum excitation control is about 30% higher than the motor efficiency under standard, default V/F control*.
*Depicted in the image to the left
