Comparative Study of the Traditional, Arctan and Robust Droop Control Techniques in an Islanded Micro-grid

The micro-grid can operate either in grid-connected or islanded mode. An islanded mode operation needs a controller to ensure voltage and frequency stability and proper power-sharing amongst distributed generation (DG) units. Droop controller has recently gained popularity among the other techniques because it does not require a communication path and is relatively inexpensive. Therefore, this paper aims to offer a comparative study of three droop control techniques, namely, the traditional droop control (TDC), arctan droop control (ADC), and robust droop control (RDC). This is accomplished by assessing each technique’s capabilities in providing accurate load power-sharing amongst DG units while also providing better voltage and frequency regulation. Utilizing MATLAB/SIMULINK software, a simple micro-grid made of two parallel-connected inverters with resistive-inductive load is used to compare the performance of these three methods. Results showed that the ADC technique provides the best frequency regulation relative to the RDC and TDC techniques. In contrast, the RDC technique gives the best voltage regulation compared to the ADC and TDC techniques. Furthermore, the RDC strategy presented lower errors compare to the ADC and TDC strategies when DG units supply the loads regarding the real and reactive power-sharing errors.