Stability analysis and control design of multi-converter systems: Literature Review

Abstract

Recently, the number of applications of power-electronics converters has increased a lot as they reduce the cost, size, power quality, reliability, flexibility, and energy efficiency. Particularly, there has been more interest in multi-converter power-electronics systems that can be applied in numerous applications such as, advanced automotive power system, Electric Vehicles, telecommunications, modern industrial electrical schemes, space station, modern aircraft, submarine, spacecraft and electric ship. Multi-converter systems exhibit interaction issues when multiple single converters are connected even though each converter is standalone stable. These interactions can even make the system unstable. In this thesis different small-signal and large-signal stability analysis methods have been discussed to analyse the stability issues. Minor loop gain based stability criteria such as Middlebrook criterion, Gain Margin and Phase Margin (GMPM) criterion, Energy Source Analysis Consortium (ESAC) criterion, and passivity-based stability criterion (PBSC) are reviewed. The thesis also reviews several control methods that can be applied in multi-converter systems. One of the recently proposed method is the positive-feedforward (PFF) control technique. Impedance-measurements of multi-converter systems can be efficiently used to control and analyse the multi-converter systems. This thesis reviews several wideband techniques that can be used for real-time stability assessment and adaptive control of multi-converter systems.