Primary and Secondary Control in Lossy Inverter-Based Microgrids

In this paper, we discuss the primary and secondary control of inverter-based microgrids. In contrast to common approaches, we neither neglect losses nor restrict the structure of primary control in order to achieve secondary control objectives. Instead, we use all degrees of freedom of primary control to accomplish frequency and voltage stability as well as approximate power sharing. We then pursue stationary accuracy of frequency regulation and power sharing by secondary control. To this end, we propose a secondary controller based on load estimation and output regulation. We illustrate the effectiveness of our approach in simulations and compare it to a consensus-based approach.