Experimentally validated resonance instabilities in distribution grids with high inverter shares

IEEE PES Innovative Smart Grid Technologies Europe, pp. 1–5

Abstract

Dynamic instabilities are increasingly being observed on different voltage levels in electric power systems with a high penetration of power electronic components. This phenomenon can be attributed to the increasing control speeds of such components. Various criteria and methods are being researched and tested to analyze this converter-driven or harmonic stability. One such criterion is the impedance-based stability criterion. It divides the analyzed system of interest into two different subsystems, each consisting of an individual frequency-dependent impedance. While such models already exist in literature, larger systemic stability investigations in low-voltage grids are still lacking. Meanwhile, power electronic components, such as EV chargers, PV inverters, etc., are increasingly being integrated in low-voltage grids in particular. In this paper, a systemic stability investigation for low-voltage grids is performed using impedances determined by laboratory measurements of real grid components. The results show that instabilities are unlikely in classical low-voltage grids with a strong connection to higher voltage levels. However, in grids operated solely by grid-forming inverters, e.g. in small island grids or solid-state transformer coupled grids, instabilities may occur. As a key result, a harmonic instability is predicted using the impedance-based stability criterion and then lab-validated.

Authors 3

1. Sandor Simon Aachen Institute for High Voltage Equipment and Grids

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW),Aachen,Germany

   Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW), RWTH Aachen University, Aachen, Germany

2. Markus Stroot Aachen Institute for High Voltage Equipment and Grids

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW),Aachen,Germany

   Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW), RWTH Aachen University, Aachen, Germany

3. Andreas Ulbig Aachen Institute for High Voltage Equipment and Grids

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW),Aachen,Germany

   Institute for High Voltage Equipment and Grids, Digitalization and Energy Economics (IAEW), RWTH Aachen University, Aachen, Germany