Constrained predictive control of three-phase voltage source converters with explicit performance specifications

Three-phase voltage source converter is one of the underpinning technologies in a renewable energy system such as wind energy generator and PV arrays. This component is nonlinear and time-varying by nature. However, with the classical synchronous frame transformation, the nonlinear model is linearized to obtain a continuous-time state-space model. Based on the linearized model, in this paper, a continuous-time model predictive control system (Laguerre function based) for a grid connected three-phase voltage source converter is designed and implemented on a laboratory scaled test-bed that was built by the authors. In the proposed design, a method known as closed-loop paradigm is applied to provide a simple tuning parameter to achieve a prescribed degree of stability and damping ratio. Constrained control of the converter is demonstrated using the computationally efficient Hildreth quadratic programming to limit the modulation of switching functions.