Potential of dynamic rating in Sweden

Power system owners are facing major challenges, for example with changed electricity consumption and production patterns; more distributed generation and increased demand of cost efficiency while maintaining high reliability. The concept of dynamic rating can act as a part solution and implies that the capacity of a component is dynamically varying as a function of external parameters such as weather and load history. This hence implies that a component can be better utilized. This can have both direct economic benefits for the utility, but also benefits for the society and the environment by lower tariff levels, faster and cheaper connection of local environmentally friendly electricity production and less climate impact associated with component production and installation. This paper gives a brief introduction to the concept of dynamic rating applied to power systems. Furthermore, results and conclusions from two workshops during 2013 are summarized, where representatives from Vattenfall and Fortum (distribution system operators), ABB (producer and developer that work with dynamic rating solutions), Swedish national grid and several persons from the academia contributed. This was complemented by interviews with the involved companies. The result is a mapping of knowledge, research, development interests, current situation and future visions. All parties show a great interest and see potential, but there are also challenges to be solved.

I. Introduction

Power system owners are facing major challenges with changed electricity consumption and production patterns; more distributed generation and increased demand of cost efficiency while maintaining high reliability. Structural refurbishments are hence needed to be increased in power systems to meet future requirements. Today, the capacity of power components often is set with static limits based on simulations of worst case scenarios. This leads to a discrepancy between the actually-available capacity and the rating itself which unfortunately is left unused. [1] In order to use this unused capacity, it is important to formulate ratings on statically-set thermal limits and sags.