A comparison of multirate digital compensators for a battery charger

In a regulation application, a power supply is typically tasked with maintaining a fixed voltage or current in the face of possible disturbances. In a tracking application, on the other hand, a controller works to cause an average output voltage or current to follow a desired reference waveform as a function of time or some other variable. This paper describes a large-signal linear, multirate digital controller for, among other possible applications, charging electric vehicle batteries. This controller permits the charger to track and deliver a desired current trajectory for a wide range of loads while providing a unity-power factor interface to the electric utility.