Current Gain Scheduling

DC power voltage can vary significantly during operation. For example, it decreases at high current due to the power supply output impedance and increases upon braking when the motor acts as a generator. These variations can result in performance inefficiencies, excess motor wear and other problems.

Elmo provides automatic current gain scheduling to compensate for variations in the DC bus power supply.  The compensation algorithm updates the current controller in order to keep loop performance stable, even when bus voltage is changing rapidly.

Before Current Gain Scheduling Function:

After Current Gain Scheduling Function:

Design Features

• DC bus voltage is filtered to avoid excessively rapid changes in current loop parameters.
• Uses a simple low-pass filter with configurable bandwidth.