The paper presents a method of the power management in a DC microgrid supported by supercapacitor as an energy storage. Power management method is presented in an example system consisting of a variable speed power generation system with a permanent magnet generator PMG, power electronics converter between PMG and DC link, and additional converter between DC link and energy storage. The system is loaded on the DC side by resistor, which represents the inverter used for the load supply. The power management method allow to obtain required functionalities like DC link voltage stabilization and overvoltage protection, supercapacitor overcharging protection and the protection against too deep discharge of the energy storage. Simulation results and laboratory tests are presented in the paper.