Frequency Control in Competitive Electricity Market Dispatch

Abstract

The dynamic and inertial characteristics of electricity systems are evolving with consequences for system frequency control. This issue is particularly important for smaller, more isolated electricity systems, where simple heuristic reserve targets may no longer be sufficient to ensure the security of the system. In a market environment, this issue needs to be dealt with in a systematic way that is compatible with the method of market dispatch to ensure least-cost operation of the system. This paper describes how frequency control constraints can be derived and included into a market dispatch algorithm. Comparisons are made with a conventional reserve target dispatch approach for a real isolated power system. The impact on market prices, cost, and the number and size of problem contingencies is assessed. The effect of increasing amounts of wind capacity is also examined.Index Terms-Frequency control, linear programming (LP), power generation dispatch, power system security.

Accommodating Variability in Generation Planning

“…For example, the commitment implied by a given dispatch can be determined and the relevant start costs and average production costs applied after. The cost of the schedule will be more accurate but the schedule will tend to be sub-optimal as the cost of starting and part-load inefficiencies will be not endogenous [23]. This alternative models have not been analyzed here.…”

An Assessment of the Impact of Wind Generation on System Frequency Control

“…The minimum operating point of generators requires that discrete decisions be made about the on or off status of the units. This problem was overcome using a two-stage rounded linear relaxation technique as detailed in [10]. Unit operating points and reserve levels are co-optimized to find a least cost solution on an hourly basis.…”

“…A detailed single bus-bar model of the Irish power system was developed, validated, and used in a number of studies [8], [10], [11], to model the response of the Irish system frequency to supply/demand imbalances. Each generator on the system, including wind generators, was represented by a dynamic model with system frequency as an input, as shown in Fig.…”

PLC based Structure for Management and Control of Distributed Energy Production Units

“…Due to environmental, economical and geopolitical reasons there will be a shift in the production of energy. More and more distributed generation will be integrated in the system, some of which have significantly different characteristics when compared to the existing large synchronous generators (Doherty et al, 2005). There should always be a balance between the supply and the demand of electricity.…”