A blackbox large signal Lyapunov-based stability analysis method for power converter-based systems

During the last few decades power converter-based systems have become a very interesting solution for electric power distribution in many applications. They have been successfully implemented in ships and “more electric aircrafts”, replacing some of the mechanical and hydraulic systems for power converters in order to optimize the efficiency and reliability of the vehicles. They have been also applied to UPS (Uninterruptible Power Systems) for applications where the efficiency or the security of supply is mandatory as in hospitals and data centers. More recently, these architectures have been proposed for Smart Grids. An important advantage of using power converters is the possibility of dynamical independence between different parts of the system. Therefore these different parts can be studied individually, drastically simplifying the analysis of large systems. However, the analysis of these parts is not straightforward, since the interconnection of power converters produces interaction between them, which can lead to dynamical degradation or even instability. This analysis is often performed by system designers, who usually do not have information about the internal architecture of the converters. Besides, the power converters behavior is operating point dependent, so in many cases small-signal techniques are not enough for these applications. Therefore, in order to cope with these issues, this paper proposes a blackbox large signal stability analysis based on the Lyapunov method.