Discrete-Time Current Control of Salient Machines With a Simplified Model

The discrete-time model for salient machines with accurate discretization is quite complicated due to different dq -axes inductances. This article proposes an approximation for the discrete-time model with high accuracy and efficient calculation. Various patterns of pulsewidth modulation updating and current sampling that result in one-sample or a-half-sample computational delay are studied, and corresponding current controllers are directly designed in the discrete-time domain with the simplified model. Decoupled responses between dq -axes are realized in reference tracking. Active resistance is also employed to improve the disturbance rejection. The experimental verification is performed on an interior permanent magnet synchronous machine.