Scheme to reconstruct phase current information of inverter fed AC drives

In modern inverter fed AC drives the current control loop is usually realised by applying two current sensors in the phases of the machine. Different schemes have been presented in the past which enable a current control loop with a single current sensor in the DC link. At low fundamental frequencies they all need to modify the standard pulse-width modulation (PWM) scheme periodically in order to update the phase current values. Here, an advanced method is presented which improves the accuracy of the phase current reconstruction, thus reducing the necessary modification of the PWM.