Voltage Deviation Suppression Strategy for Hybrid AC/DC Distribution Networks with Multiple Power Electronic Transformers

The volatility and intermittency of distributed energy sources, such as wind turbines and photovoltaics, can disrupt the coordination between their power outputs and the control variables of power electronic transformers (PETs) in hybrid AC/DC distribution networks. This often results in voltage deviations or limit violations, compromising system stability. This paper introduces a strategy leveraging the flexible control capabilities of PETs to mitigate voltage deviations. A two-layer optimization model is proposed, and it is solved using an enhanced whale optimization algorithm with improved sample generation. Case studies on an improved IEEE 33-node hybrid AC/DC distribution network demonstrate the strategy's effectiveness by comparing voltage profiles and control variable adjustments before and after optimization.