Derivation of a Stationary-Frame Single-Loop Controller for Three-Phase Standalone Inverter Supplying Nonlinear Loads

In this paper, a stationary-frame, single-loop controller for three-phase standalone inverter supplying nonlinear loads has been derived from synchronous reference frame proportional-integral multiloop controller. In this method, load voltage harmonics are eliminated by a single loop and only one control variable. The proposed method has several advantages such as lack of Park transformation and requires tuning only one control parameter. It can also be implemented with less computational burden, less complexity, and easier tuning, compared to conventional proportional-integral multiloop controller. Experimental results with laboratory prototype under linear and nonlinear load conditions validate the proposed method.