Exhaustive Modal Analysis of Large-Scale Interconnected Power Systems With High Power Electronics Penetration

Abstract

Eigencalculation is a challenging task in large-scale power systems with high power electronics penetration for at least two reasons. First, the well-known inter-area modes are no longer the only coupling modes as such couplings may involve also power converters. Next, it is difficult to find all coupling modes without a priori knowledge about them (frequency or path of oscillation). In this paper we propose a new method to overcome these difficulties. It is fully analytic, i.e., does not need operator manipulations like dynamic simulations, and it is exhaustive in the sense that makes a full scan of the system for coupling modes. The approach involves concepts from matrix computation and dynamic systems analysis which hold in largescale and need no hypothesis (like the one about large inertia generators usually associated to inter-area modes) or knowledge about the structure of the power system. Validations on several models are presented, including realistic large-scale model (more than 1000 generators/dynamic devices) of the European power system.

Exhaustive Modal Analysis of Interconnected European Power System

“…In fact, an exhaustive analysis should be able to determine all oscillatory modes, not only the inter-area modes, but also the electrical modes (modes related to the electrical parts of distant classic generators and the ones related to the PPMs). For example, In [1], [2], [6] and [7] coupling modes associated to electrical part of the distant calssic synchrounous generators are highlighted but not of inter-area nature. In [8], and [7] oscillatory modes associated to converters of distant HVDCs, PVs and winds were also highlighted and analysed.…”

“…For example, In [1], [2], [6] and [7] coupling modes associated to electrical part of the distant calssic synchrounous generators are highlighted but not of inter-area nature. In [8], and [7] oscillatory modes associated to converters of distant HVDCs, PVs and winds were also highlighted and analysed. Therefore, all these oscillatory modes will be called coupling modes in the sequel.…”

“…This supposes that some knowledge about the system is available which is not always the case. To overcome these difficulties, two exhaustive methodologies were discussed and developed in our previous works [6], [7]. In fact, they provide a way to systematically excite and put into evidence all the coupling modes of a given power system.…”

“…To put into evidence all the European power system modes, the method proposed in [7] is used here with some modifications for large-scale use. Importantly, the analysis of the European power system or of a system of comparable size and complexity in exhaustive way is a novelty in modal analysis and has never been addressed before.…”

“…As well, aggregating the dynamic devices according to the nature of the coupling modes or according to the oscillation frequencies it is also possible. Preliminary modal analysis results of the European power sysem were presented in [7]. The analysis is carried out on the Dynamic Reference Model (DRM), which was developed for the IPS/UPS EC study and next maintained [11].…”