The Impact of Uncertainty and Time Structure on Optimal Flexibility Scheduling in Active Distribution Networks

Abstract

The authors focus on a model for system operators that uses centralized scheduling of multiple flexibility assets and services to minimize the cost of managing problems with grid congestion, voltages, and losses. The model schedules flexibility assets using stochastic optimization for AC optimal power flow in an active distribution network. The novelty of the contribution lies in its focus on how the dynamic capabilities of the flexibility resources are defined with regard to how uncertainty is resolved in the model. The impact of uncertainty is studied by using well-known quality measures from stochastic programming, such as the value of the stochastic solution. Moreover, the authors introduce a new measure related to the impact of representing uncertainty and flexibility when considering reactive power. By changing the time attributes of flexibility assets, the authors show the impact of uncertainty and time structure on a scheduling problem. The uncertainties considered are price and load levels. The findings reveal that the quality of the scheduling of each flexibility resource depends on using a stochastic model with a rigorous consideration of time and uncertainty.INDEX TERMS Flexibility, active distribution networks, optimal power flow, scheduling, stochastic programming, uncertainty. NOMENCLATURE

Interoperability Testing for Explicit Demand Response in Buildings

“…On the other hand, although in [19], the topic of residential aggregation is examined, scheduling is the main focus, and testing the interaction among components is not addressed. The same goes for [16], where stochastic scheduling is proposed for flexibility. In [17], the interactions of assets are examined along with their scheduling under specific constraints but testing the smooth interaction between assets and the aggregator or DSO is not examined.…”

“…On the other hand, efficient energy management is the objective in [15], where a mutual optimal solution was proposed both for utilities and customers. Flexibility scheduling is also examined in [16], where price and load levels are taken into consideration as the uncertainties for the stochastic scheduling program. In [17], the coordination of multiple residential assets on behalf of a flexibility service provider is proposed, taking into consideration the constraint of having a maximum of 10 connection points providing flexibility control within a radius of 100 m. The scheduling of appliances within the house is also the research objective in [18], where the authors propose an algorithm for optimal appliance scheduling for the residential sector.…”

Adaptive Grid Partitioning Considering Power Supply and Load Distribution

“…The total capacity of the unit is 5000 MW, and the total capacity of the renewable energy unit is 700 MW. Access fluctuating loads at nodes 2,6,11,14,17,19,22,36,38. Except for nodes connected to renewable energy units and fluctuating loads, the power supply and loads of other nodes are fixed.…”

“…According to the North American Power Reliability Association, system flexibility is the ability to respond to uncertainties in the system by mobilizing resources at your disposal. The [11] evaluates power system flexibility from a net load demand perspective. The [12] evaluated the flexibility of the power system by using power climbing rate as an indicator.…”