Power System Computation Conference location:Wroclaw date:August 18-22 2014
When the design of future electricity infrastructure is studied on a decadal scale, it is usually first assessed using a set of generation mix assumptions, with the network represented as transport model that does not obey Kirchoff’s laws. Rough flow requirements are obtained, but because regions or countries are represented by a single node, further analysis is required to obtain network design requirements. This paper proposes metrics for assessing the transit properties and flexibility of a transmission network based on the simplest circuit representation capable of describing components of flow in a planar network. By analyzing the spherical power injection space of a specific four node equivalent network, both large signal aspects such as line flow constraints and small-signal aspects such as Kirchoff’s laws are accounted for. As an example, these metrics are applied to selected European countries to compare the properties called for by European energy policy against the basic properties of existing high voltage networks.
The injections admitted by an impedance and flow constrained network comprise a volume in the power injection space. This paper introduces characteristic cross-sections of the power injection space that can be used to “measure” the network’s capability. These measures can be combined to produce geographically oriented maps indicating the directional flow, curl, and source/sink capability of AC and DC transmission systems. The full paper will present a method to analyze future grid capabilities, particularly the flexibility brought by adding controllable devices (HVDC, FACTS). The analysis methods can be used by grid planners to analyze grid investment requirements and the effect of possible investments.