Operation and control of island systems-the Crete case

Abstract

In this paper, an advanced control system for the opt1 mal operation and nianagenient of isolated power svstenis with increased renewable power integration is presented The control system minimises the production costs through on-line optimal scheduling of the power units, taking into account short-term forecasts of the load and the renwable resources. The power system security is supervised via on-line security assessment modules, which emulate the power system frequency changes caused by preselected disturbances. For each of the above functions, a nuinber of techniques has been applied both conventional and AI based. The system has been installed in the Dispatch Center of Crete since June 1999, and is currently under e\Valuation.

Quantifying the Total Net Benefits of Grid Integrated Wind

“…Thus, for each hour, the commitment decisions are made 6 hours ahead of that hour and the dispatch decisions are made virtually at real time. This two stage approach, with commitment and dispatch taking account of wind power forecasts, has also been adopted in the Siemens PROMOD software, used in [8], and the two stage methodology is also employed in the MORE CARE control software, which is described in detail for an island system in [5], [9]. An alternative economic dispatch model which includes network constraints using genetic algorithms to dispatch an island system with wind is described in [45].…”

“…This increase in the required reserve is a cost to the system imposed by the wind generation [7]. In addition, an increase in variable generation on an electricity system may require the system operator to alter how conventional generation is dispatched [8] [9]. Conventional This work has been conducted in the Electricity Research Centre, University College Dublin which is supported by Electricity Supply Board (ESB) Networks, ESB Power Generation, ESB National Grid, Commission for Energy Regulation, Cylon, Airtricity and Enterprise Ireland. E. Denny generation may be obliged to operate at lower operating levels in order to be available to ramp up or down to accommodate the inherent variability of the wind generation.…”

Online preventive dynamic security of isolated power systems using decision trees

“…1. The economic dispatch and dynamic security functions are performed successively as part of an inner loop, also including load and renewable forecasting and unit commitment functions [17]- [19]. Following extensive tests on Crete, the iteration step of this inner loop has been set to 20 min with an 8-h optimization horizon.…”

“…The load shedding or unsupplied energy cost (UEC) and the additional production cost (APC) incurred by the corrective redispatch are shown in Table VI. The total net cost of the security provided is 5939.25 , which amounts to 19.2% of the total extra system operation cost of 30 935.41 . It should be noted that in Cases 4 and 5, the UEC is lower than the extra generation cost.…”

“…Online DSA functions based on DTs, as well as artificial neural networks (ANNs), and kernel regression trees (KRTs) [13]- [16] have been developed and integrated within an advanced control system tailored for the needs of isolated power systems with increased renewable power penetration within the framework of the CARE European R&D project [17]- [19]. The control system has been installed on Crete, the largest Greek island, and is currently used to assist its operators by proposing optimal operating setpoints for the various power units, both conventional and renewable.…”