Overview
This research addresses the economic dispatch (ED) problem in large-scale microgrids, which are typically composed of several cross-regional subgrids aggregated by a virtual power plant (VPP). The study proposes a distributed cluster consensus control scheme that utilizes communication weights to achieve differential demand features between subgrids, a capability not guaranteed by current consensus-based methods.
Research Context
Large-scale microgrids, characterized by their aggregation of cross-regional subgrids under a VPP, present challenges for effective power dispatch. Existing consensus-based schemes often fail to accommodate the distinct demand profiles of individual subgrids. The objective of this work is to overcome this limitation by developing a distributed control approach that can generate specific cluster formations and distribute power efficiently while maintaining supply-demand balance.
Approach
The core of the approach involves a distributed cluster consensus control strategy induced by communication weights. This strategy is designed to solve the ED problem for large-scale microgrids. A key component is the design of a communication weight matrix for directed and connected graphs, which is developed using eigenvector centrality. This design ensures that the adjacency matrix of the communication network possesses a pre-defined leading eigenvector, and that agents within each cluster share the same eigenvector center value.
Based on this foundation, a distributed cluster ED scheme is formulated. This scheme operates as a leader-follower cluster consensus controller. Its function is to drive the marginal cost (MC) of the distributed generators (DGs) to achieve multi-consensus. This multi-consensus then facilitates the appropriate allocation of power among the DGs.
Additionally, the scheme incorporates a mechanism for managing power deficits. Power deficits collected by the VPP from each subgrid can be allocated to utility grids according to pre-established ratios. This allocation mechanism aims to maintain the power supply-demand balance within each subgrid.
The proposed scheme operates within a specific network topology: the weighted network utilized is directed and connected. A further condition is that leader information is accessible only to a limited number of clusters. To substantiate the efficacy of the developed scheme, relevant simulations were conducted and appended to the paper.
Findings
- A distributed cluster consensus control method was investigated utilizing communication weights to address the economic dispatch problem in large-scale microgrids.
- The scheme enables the achievement of an expected cluster structure through well-designed communication weights, differentiating it from current consensus schemes that cannot guarantee differential demand features between subgrids.
- A communication weight matrix design method was developed for directed and connected graphs based on eigenvector centrality. This method allows the adjacency matrix of the communication network to have a given leading eigenvector and ensures agents in each cluster possess the same eigenvector center value.
- A distributed cluster economic dispatch scheme, implemented as a leader-follower cluster consensus controller, was designed to drive marginal costs to achieve multi-consensus, thereby allocating power among distributed generators.
- The scheme allows power deficits of each subgrid, collected by a virtual power plant, to be allocated to utility grids based on predetermined ratios, thus maintaining power supply-demand balance in each subgrid.
- The scheme operates under the conditions of a directed and connected weighted network, with leader information accessible only to a few clusters.
- Simulations were provided to verify the effectiveness of the designed scheme.
Why This Matters
The ability to address the economic dispatch problem while ensuring differential demand features between subgrids in large-scale microgrids can lead to more efficient power distribution. By enabling the allocation of power deficits to utility grids based on predetermined ratios, the scheme offers a mechanism for maintaining supply-demand balance within individual subgrids, which is critical for system stability.