Modeling and control of inverter-based microgrids⁎

Assuming the most common control structure for zero and primary control of inverter-based microgrids, i.e. three cascades with the highest one being droop control, the potential benefit of optimizing the control parameters is investigated. A detailed nonlinear plant model is derived that compactly describes the dynamics in local dq-coordinates. Then, the design of the decentralized, cascaded controllers is converted into the problem of designing one centralized static controller with structural restrictions. To tune the controller parameters, a direct method for pole-assignment is used. The simulations show that the oscillations in the transient response can be reduced greatly by choosing appropriate control parameters, while the speed of the system is restricted due to the low-pass filtering of the power for primary control.