Design of Digital Controllers for Grid- Connected Voltage Source Converter Operating as Voltage or Current Source

Digital controllers for grid-connected voltage source converters GC-VSC offer a noteworthy alternative to traditional continuous- time control systems. A power grid often comprises inverters, grid- forming and grid- following converters, renewable energy source units, and various local loads. Currently, the design of GC-VSC controllers is subject to restrictions and additional considerations following standards and technical recommendations for their control when operating connected or disconnected from a power grid, mainly to maintain the stability of the control system. In this context, this paper presents the design of the GC-VSC digital controllers, using mainly the concepts of dead- beat control. Thus, the main result of this project is to improve the modeling and control of the single- phase GC-VSC using the digital control method. The relative RMS errors of the GC-VSC current and load voltage are \(\epsilon _{i_{f}}\)  = 3.67 % and \(\epsilon _{v_{o}}\)  = 0.01 %, respectively, i.e., the controller showed tracking accuracy. Simulation results using MATLAB/SIMULINK are presented to validate the proposed controllers.