Coordinated Power Management for the Integration of Active Distribution Networks with High PV Penetration into the Medium Voltage Grid

The power injected from large scale active distribution networks (ADN) with intermittent resources to the grid should be coordinated to support grid stability. The paper proposes power management strategies to counter-balance power fluctuations from ADN with high penetration level of photovoltaic (PV) and to supply ancillary services to the host medium voltage (MV) grid. This is achieved through two stages: offline optimization stage and coordinated control stage. In the first stage, the pattern of the power injected from the ADN to the grid was determined. In the second stage, a coordinated power management strategy was developed to support ancillary services to the hosting grid. The operation of the system was thoroughly investigated by designing the control loops for steady state and transient conditions. The effectiveness of the proposed strategy was validated under different scenarios. The dynamics of the control loops were investigated using the PSCAD/EMTDC software package. The results showed the effectiveness of the coordinated control in supporting ancillary services to the host grid and limiting the power fluctuations at the grid side.