Research on Voltage Balancing Strategy in UPFC Feedback Control Based on Tagging Model

During the operation of the Unified Power Flow Controller (UPFC), various data are generated and accumulated. In order to better meet the equipment management requirements, this paper designs a UPFC tagging model using equipment profiling techniques and proposes an enhanced K-means tagging technique. During UPFC operation, voltage imbalance in capacitors may occur, and conventional all-time access voltage controllers may cause harmonic reverse injection, polluting modulation waves. Accordingly, this paper first quantifies the imbalance of capacitor voltages using tagging model and proposes an optimization strategy for capacitor voltage balance based on feedback adjustment. Through clustering analysis of capacitor voltage imbalances and defining different tag ranges, this strategy selects the optimal time to connect voltage controllers when capacitor voltage imbalances are high. Furthermore, simulations conducted on PLECS validate the effectiveness of the proposed strategies.