Parameter-Dependent Relay Control: Application to PMSM

This brief presents a novel relay control design strategy for some classes of nonlinear systems. The main idea of this brief is to use a linear parameter-varying (LPV) modeling to design nonlinear switching surfaces. This modeling is motivated by the fact that numerical tools, such as linear matrix inequality (LMI), may be used by exploiting the quasi-linear structure of the system. Here, we propose an LMI formulation providing criteria for the design of switching surfaces. This design is seen as the synthesis of parameter-dependent relay. The second contribution of this brief is the implementation of this relay strategy for permanent magnet synchronous motors (PMSMs). Since the LPV framework can encompass the PMSM model, the obtained relay control depends on the motor speed variations. Experimental results on a PMSM are presented.