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Center for Nonlinear Studies |
On the distribution side of a power system, there exist many distributed energy resources (DERs) that can be potentially used to provide ancillary services to the grid they are connected to. An example is the utilization of power electronics grid interfaces commonly used in distributed generation to provide reactive power support. While the primary function of these power electronics-based systems is to control active power flow, when properly controlled, they can also be used to provide reactive power support. Another example is the utilization of plug-in-hybrid vehicles (PHEV) for providing active power for up and down regulation. For instance, such resources could be utilized for energy peak-shaving during peak hours and load-leveling at night. Proper coordination and control of DERs is key for enabling their utilization for ancillary services provision. One solution to this problem can be achieved through a centralized control strategy where each DER is commanded from a central controller located, for example, at the substation that interconnects the distribution network and the transmission/subtransmission network. In this talk, we propose an alternative approach to this centralized control. The alternative approach rely on a distributed control strategy where each DER can exchange in- formation with a number of other “close-by” DERs, and subsequently make a local control decision based on this available information. Collectively, the local control decisions made by the DERs should have the same effect as the centralized control strategy. Such a solution could rely on inexpensive and simple communication protocols, e.g., ZigBee technology, that would provide the required local exchange of information for the distributed control approach to work. We provide algorithms that solve this coordination/cooperation problem when i) there is no limit on the amount of active or reactive power that each DER can provide (though some notion of fair distribution of the contribution of active or reactive power among DERs might be imposed); and ii) the maximum amount of active or reactive power each DER can provide is limited, which is a more realistic case. We will provide a careful analysis of the applicability capabilities and limitations of each of these strategies.
Host: Misha Chertkov, chertkov@lanl.gov, 665-8119