Identification of observables for future grids - The framework developed in the ELECTRA project

Abstract

Abstract-The main subject of this paper is the classification and identification of observables for present and future grids. In order to make an inventory of present and potentially new observables, a systematic classification and identification of observables for future grids is conducted. After first introducing some fundamental definitions for observables, observables are further classified by the characteristic time scale where they are used in the physical power system. For actual use in control loops, observables must be part of so-called "Control Triples" consisting of control aim, observable, and system input signal. A survey of existing and potential Control Triples was conducted among partners in the European ELECTRA project, resulting in a spreadsheet inventory. The main findings are presented and a few major observability needs for realising the so-called "vertical integration" of control schemes reinforced by "horizontal integration" of distributed control schemes in the future grid.

Aggregation of single-phase electric vehicles for frequency control provision based on unidirectional charging

“…The modelled grid is called the Pan-European grid and is used for research purposes in the European project ELECTRA IRP [11], [12]. The grid is built up to resemble the European transmission grid with its transmission voltages and a grid frequency of 50 Hz.…”

Validating a centralized approach to primary frequency control with series-produced electric vehicles

“…A noticeable amount of research efforts is put nowadays to investigate all different aspects needed to shift from the traditional power system, where frequency and voltages are controlled by a relatively small set of large units, into a futuristic system, where potentially all power devices can be involved in the controlling actions. For instance, in the ELECTRA project, innovative control schemes are being investigated in order to assess whether conventional frequency and voltage controlling approaches are still suitable, or which aspects need to be revised for scenarios with massive amounts of small distributed energy resources [1,2]. It is argued that TSOs alone will not be able to effectively manage the overall system balance and will have to partially delegate frequency control responsibility to DSOs as already happens today for congestions management and volt-reactive power provision [3][4][5][6][7][8][9][10].…”

A decision support tool for transient stability preventive control

“…the control room operator is not provided with the needed information [5][6][7]. Therefore, appropriate monitoring, visualization and decision support tools have to be developed to support the decision making process and to prevent or properly respond to electrical incidents in order to maintain power system 10 stability [8,9]. Dedicated decision support tools are needed to facilitate the incorporation of high shares of renewable energy sources (RES) while keeping the power system operative and stable [10].…”