Voltage Regulation Controller in DC Microgrid: Implementation Challenges and Solutions

This paper presents the challenges and solutions in implementing the voltage regulation loop of the distributed secondary controller for dc microgrid in a digital signal processor (DSP). Secondary controllers are generally used to keep the average dc microgrid voltage at the nominal value. However, some unforeseen issues may hamper the operation of the secondary controller. One of such issues is the saturation of controllers due to the lower resolution of the variables in DSP. This, in turn, results in the average terminal voltage deviating from the desired value. This work focuses on addressing this particular problem. Different variables related to the secondary controllers are observed from the DSP. The buildup of these variables is correlated with theory to arrive at a solution. Although there are multiple publications on secondary controllers, practical challenges and issues are not discussed in sufficient detail in the literature. The efficacy of the proposed solution is validated in a scaled-down DC microgrid prototype.