Converter induced resonances in microgrids due to high harmonic distortion

Abstract

This paper describes the resonance introduced by harmonics amplification and adverse interaction of electronic converters. An observation of undamped oscillation leading to instability in a microgrid is described. The term "converter induced resonances" is proposed to describe this phenomenon. The amount of distributed generation, active loads, FACTS and battery energy storage systems are expected to increase in future Smart Grids. All these resources will be interfaced with electronic converters. The potential impact of converter induced resonances in such grids is described. A coordinated design of the control systems of all converters is in practice not feasible. Each device will be independently tested to fulfil grid codes and have its own converter control implemented that can include functionality to modify voltage and /or current waveform.