Layered control structure for high-frequency control in drive applications

Switching frequency of a drive control system is often determined by the characteristics of the switching components. With new fast switching wide band-gap semiconductors, the bottleneck will no longer be the switching component, but the computing power to process the control algorithm. This paper presents a broad overview of considerations on the high frequency control of drives and deduces simple rules of thumb for design of feedback control systems. Requirements for a control system to cope with the new balance between switching frequency, control bandwidth and computing power are deduced. A layered control structure is proposed, with different control bandwidths per layer.