Dual Mode Control of a Three-Phase Inverter Using Minimum Variance Adaptive Architecture

This paper presents a system identification based minimum variance control architecture for three-phase voltage source inverters that work seamlessly in both grid connected and grid forming modes. The controller is adaptive as parameters in the control law are updated online based on an identified system that relate the inverter output to input. Main advantages of the proposed controller are 1) it can be used in both modes of inverter operation and 2) the controller adapts under varying operating conditions, thus capable of accommodating uncertain energy resources and yet maintaining the power quality. First, the design of the controller is presented and simulation results from test performed using MATLAB SimPowerSystems along with hardware-in-the-loop implementation are illustrated. Second, operation of the inverter controller in the context of micro grids is discussed. The results show that the proposed controller can be a better alternative to the existing cascaded PI based vector control for both grid connected and grid forming modes of operation.