A Method for Correcting Frequency Estimates for Synthetic Inertia Control

Evaluating Methods for Measuring Grid Frequency in Low-Inertia Power Systems

“…The standard DFT algorithm was based on the example in IEEE 60255-118-1 [9], with a slight modification in the antialiasing filter. The code was provided by Wilches-Bernal [2].…”

“…One solution proposed by NERC to avoid false tripping was to increase the time delay before inverter trip. However, this solution would not work for other purposes as near-instantaneous controls are needed in grids with high penetrations of renewables [2], [3]. As IBR use increases, we must develop fast frequency measurement algorithms that can handle large frequency and ROCOF deviations [4].…”

“…Accordingly, many research efforts focused on rejecting frequency spikes by detecting phase steps: one author proposed a DFT-based method with a phase-step detector which freezes the frequency measurement during the phase step [6], [7]. Another author modified the extended Kalman filter (EKF), quadrature PLL (QPLL), and adaptive notch filter (ANF) methods with a corrector which freezes frequency measurement during a transient then ramps back to real-time measurement [2]. A PMU-based method employed an estimator block, which replaced realtime phasor data when a phase step was detected [5].…”

On the Tuning of Fractional Order Resonant Controllers for a Voltage Source Converter in a Weak AC Grid Context

“…Being superscript OL the open-loop transfer function and superscript CL the closed-loop transfer function in (4). The derived closed-loop transfer functions from the openloop PR control structures are compared in terms of their frequency behaviour in Fig.…”

“…Digital models for dynamic and transient simulation of energy conversion systems are becoming the cornerstone of research in multi-port advanced conversion systems in order to predict their behaviour in unexpected but ever more and more frequent circumstances. In this vein, the weakening of AC grids due to dynamic impact of nearby grids with high content of power electronic-based RES [3] or challenges for inertial response [4] are scenarios that may command a new design of control schemes or new parameterisations. Therefore, simulations are a powerful tool to study such scenarios and redesign control schemes, as they allow to work with simplified representations of multi-port energy conversion systems for large system studies [5].…”