Decentralized Fast Delayed Signal Cancelation Secondary Control for Low Voltage Ride-Through Application in Grid Supporting Grid Feeding Microgrid

Abstract

In this study, a distributed secondary control is proposed alongside the conventional primary control to form a hierarchical control scheme for the Low Voltage Ride-Through (LVRT) control and applications in the inverter-based microgrid. The secondary control utilizes a fast Delayed Signal Cancelation (DSC) algorithm for the secondary control loop to control the reactive and active power reference by controlling the sequences generated. The microgrid consists of four Distributed Energy Resources (DER) sources interfaced to the grid through interfacing inverters coordinated by droop for effective power-sharing according to capacities. The droop also allows for grid supporting application for microgrid’s participation in frequency and voltage regulation in the main grid. The proposed decentralized fast DSC performance is evaluated with centralized secondary and traditional primary control using OPAL-RT Lab computation and MATLAB/SIMULINK graphical user interface for offline simulations and real-time digital simulator verification. This study presents and discusses the results.

Modeling of Double Stage Photovoltaic Inverter System with Fast Delayed Signal Cancellation for Fault Ride-Through Control Application in Microgrids

“…Consequently, the required reactive current injection under fault in the AC grid is guided by the given expression. Once the PCC voltage sequence components are obtained in direct-quadrature coordinates when grid failure occurs using Equation (18), broken down into Equations ( 19) and ( 20), the two PCC voltage-independent control systems restore normal sequence references. Positive sequence control aims to bring the PCC voltage's positive sequence level back to its rated value.…”

“…Aside from FRT, future inverter-based microgrid systems are expected to integrate grid support, grid fault resistance, dynamic power regulation, and smart ancillary service supply at the PCC [17,18]. Additionally, as soon as the grid voltage recovers or the fault is cleared, the PV system is required to function at its maximum active power point for a set time at a power factor of unity.…”

Modelling of a Photovoltaic-Based Grid Supporting Microgrid and Fault Ride-Through Control Application

“…The Pω droop control adjusts the active power output of the inverter based on the deviation between the actual grid frequency (ω) and the reference frequency. By incorporating this droop control, the inverter actively contributes to regulating the grid frequency, maintaining it within the desired range [18].…”