Power System Black-Start and Restoration with High Share of Power-Electronic Converters

Abstract

In this paper, a systemic approach for Restoration and Black-Start capability of a large-scale interconnected Power System model is investigated. In the developed model for Electro-Magnetic Transients (EMT) simulations, there are three areas with different devices interfaced to transmission network via voltage-source converters (VSC), including seventeen wind power plants (WPP), seven battery-energy storage systems (BESS), and two HVDC transmission links. Of the total energy produced in this model, 90% is generated by the WPP and the other 10% by conventional generation units (CGU). The control systems that regulate the WPP and the HVDC Systems were upgraded with Grid-Forming capability. Therefore, the power system model is suitable for simulations during both steady-state and transient operational scenarios. If the latter case may derive in a Blackout, it allows simulating black-start and restoration. The Model was designed in DIgSILENT PowerFactory 2018 and its proposed grid-forming and black-start capabilities were tested with several EMT simulations reproducing severe short-circuit faults, deriving in a full blackout in one of the areas of the power system. The model also was upgraded with five protection relays with a restoration algorithm that determines the best re-energization path for the fastest possible restoration strategy. The simulation results endorse that a power system with high penetration of converter based-generation and transmission is completely capable of manage a grid during all circumstances if its control systems are designed to do so.