MCAT algorithm for coordinated voltage instability preventive control in smart grids

The necessity for coordinated Voltage Instability Preventive Control (VIPC) is crucial for modern power networks hosting large-scale Renewable Energy Sources (RESs). The RESs can create voltage instability due to their output power fluctuation, their rapid-response devices, as well as the operational conflicts with conventional Preventive Controls (PCs). This work proposes a novel Multi-Criteria Accumulating and Testing algorithm, namely MCAT, for coordinated VIPC in smart grids. The algorithm mainly involves five modules: Voltage Stability Assessment (VSA), Impact Factor (IF), Control Ranking Index (CRI), Accumulation Strategy (AS), and Testing Strategy (TS) modules. First, system Voltage Stability Margin (VSM) is estimated using VSA module. The IF module is then used to reflect the dependencies between PCs and bus VSMs. The CRI module is used to rank the PCs according to a set of operational and economic criteria. The CRI module is mainly based on a Multi-Criteria Decision-Making (MCDM) strategy. The CRI results are implemented into AS module to sequentially identify the global group of control variables to simultaneously eliminate the impact of all system contingencies. Finally, the AS results are tested using TS module to remove any useless PCs. The proposed algorithm was tested and validated on the IEEE 118-bus system. The results show that MCAT algorithm was able to select only the most effective and the cheapest PCs for VIPC with an objective to eliminate all system contingencies with no useless controls.