Day-ahead Scheduling of AC/DC Hybrid Power Systems Considering the Optimization of LCCHVDC System Operations With Online Power Reversal

With the increasing installed capacity of new energy generation and the advancement of High-voltage direct current (HVDC) technology, the development of Online Power Reversal of Line-commutated Converter High Voltage Direct Current (LCCHVDC)technology has become essential to improve the utilization of existing resources and meet the need for flexible power regulation. However, research on the optimal dispatch of power systems embedded with power reversal of LCC-HVDC modes remains limited. To explore the flexibility of LCC-HVDC, a modeling method for integrating power reversal of LCC-HVDC into the day-ahead generation scheduling of AC/DC hybrid power grids is proposed. This paper first constructs an optimization model for online power reversal in LCC-HVDC systems using the equivalent virtual machine approach. The model comprehensively considers the power adjustment requirements during the operation of online power reversal, including constraints on the direction, frequency of power regulation, and power flipping control. Through reasonable constraint settings, the model effectively avoids the potential reduction in equipment lifespan due to frequent operations. Secondly, based on the proposed LCCHVDC online power reversal model, a day-ahead power generation and transmission scheduling model that incorporates its flexibility is developed, and the detailed transformation and solution methods for this model are elaborated. Finally, the effectiveness of integrating the proposed LCC-HVDC model into the Security-Constrained Unit Commitment (SCUC) problem for joint optimization is demonstrated through validation on a modified IEEE 14-bus system.