ADMM-Based Distributed Optimization of Hybrid MTDC-AC Grid for Determining Smooth Operation Point

Accompanied by the rising fashion of distributed energy resources requiring distributed optimization is becoming more prevalent among power system. However, research for distributed optimization to determine smooth operation point (SOP) has attracted less attention in hybrid multi-terminal high voltage direct current (MTDC) and thus, it is still a core issue. The proposed method mainly designed to deal with SOP, and this goal can be mainly achieved by taking minimal line losses and smoothness objectives (MLLSO), which is formulated as an MLLSO optimization model. Then, the MLLSO optimization is transformed to single-objective distributed optimization through weight normalization of both objective functions. A minimal line loss objective and smoothness objective-based optimal power flow (MLLOSOBOPF) model is built at first to effectively handle prevailing constraints for the power systems parameters. Then, the alternating direction method of multipliers (ADMM) is utilized to solve this model by breaking it into smaller pieces based on OPF, each of which is easier to handle. In addition, different sized power systems are integrated with the 14-bus and 30-bus hybrid MTDC-AC systems to increase the complexity of test systems. Finally, based on 14-bus and 30-bus hybrid MTDC-AC systems, the computational output and comparison of the proposed method with centralized optimization centralized MTDC show that the proposed method is feasible and effective for determining hybrid MTDC grid SOP.