Abstract：As the result of low voltage, small capacity and widely use of electronic-interfaced micro-sources, the power transmission characteristics of LV microgrids are very different from those of HV grids. In this paper, these differences are compared and analyzed, and the analytical expressions of the active power P and reactive power Q in terms of the amplitudes and power angle between two micro-sources are obtained. The results show that, due to the different characteristics of transmission lines, the natural power distribution in two kinds of grids is very different; and quantitative analytic results are given through simulation. Then the inverter output characteristics required by micro-sources interconnecting in microgrid are discussed. Simulation results of the inverter output voltage amplitude, phase and frequency control are given. At the end, aiming for the smallest line power loss, active power optimization among the micro-sources in the microgrid is simulated.
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2010, Vol. 25 
