Economical Secondary Control of DC Microgrids

This paper proposes a distributed secondary voltage and current control aiming at economic dispatch of DC micro-grids. The dispatch problem is solved with the Lagrange method resulting in the equal incremental costs criterion. The proposed secondary controller realizes this criterion by using an average data consensus algorithm. A distributed dynamic data corrector is also proposed which ensures that the generators' output currents are always kept within the allowable ranges and that the total generation cost is as optimum as possible. Both physical and control systems considering constant impedance-current loads are formulated and stability of the system is briefly discussed. To verify the effectiveness of the proposed scheme, a test microgrid system is simulated in MATLAB/Simulink environment.