Voltage source converter MPC with optimized pulse patterns and minimization of integrated squared tracking error

Model predictive control schemes for power electronic applications are characterized by a great variety of problem formulations. In this paper, we consider a three phase voltage source converter with an arbitrary number of voltage levels and derive a model predictive control scheme involving a combination of optimized pulse patterns and the integral of squared predicted tracking error as a cost function. We obtain a nonlinear optimization problem with the switching times as optimization variables, and solve it using gradient projection algorithm. To obtain an easier optimization problem to be solved on-line, a linearization around nominal switching instants is performed bringing the problem to a quadratic programming form. Simulation results demonstrating the performance of the derived scheme are provided for the case of a grid-tied converter with LCL filter.