Power coordination in variable speed drives using model predictive control

Abstract

Variable speed drives (VSDs) are used to convert power between electricity grids and electric machines. Typically, they are AC-DC-AC power converters consisting of a rectifier, a storage capacitor and an inverter. In this paper, we use model predictive control (MPC) to coordinate the power flow through a VSD in order to keep the stored DC energy within tight bounds, exceeding the capabilities of conventional proportional-integral (PI) control techniques. The use of MPC enables for drives with smaller storage capacity that operate close to their physical capabilities. We design an MPC procedure that is tailored to VSDs and that accounts for real-time operation aspects.