Smart Transformer-Assisted Frequency Control Mechanism for RES Penetrated Power Systems Considering Metaheuristic-Based Secondary Controller

Abstract

The gradual replacement of conventional generators with variable renewable energy sources (RES) will reduce their online frequency regulation (FR) resources and degrade their overall frequency control capabilities. Although various inertia emulation methods exist, shaping load consumption is considered a more effective strategy during emergency conditions than under-frequency load shedding. Managing loads following frequency excursions can support grid stability owing to rapid power response. In this context, a Smart Transformer (ST)-based FR framework for a RES-penetrated power system is studied in this paper. The ST, with its distinctive features, effectively shapes the load profile through online load sensitivity identification-based control, aiding in the stabilization of grid frequency. This paper also proposes a tilt integral second-order double derivative (TIDD2) controller for a secondary loop whose parameters are optimized using the Learner Performance-based Behavior (LPB) algorithm. A thorough investigation reveals that the response from ST controlling the voltage-dependent load in the presence of TIDD2 controllers can greatly enhance system performance by damping oscillations and peak deviations. In addition, the performance of Proportional–Integral–Derivative and TIDD2 considering ST in the primary loop is compared to delineate the robustness of the LPB-based TIDD2 controller. It is found that the proposed control scheme offers greater controllability and flexibility, enhancing the system’s dynamic performance.

Keywords

• load frequency control
• frequency regulation
• smart transformer
• voltage-dependent load
• learning performance behavior-based optimization