Aggregation Feasible Region of Full Power Spectrum Electric Vehicles Based on Polyhedron Projection

The aggregation of electric vehicles (EVs) can take full advantage of the power flexibility of EV clusters, based on the aggregation feasible region (AFR) of EVs. However, existing aggregation techniques of conventional distributed energy resources (DERs), exhibit significant inaccuracies or require excessive computational efforts when applied to EVs with high power and small capacity. To solve this problem, an iterative method based on the high dimensional polyhedron projection principle is proposed to derive the exact AFR formula for the full power spectrum of EVs, and the limitations of the existing analytical AFR are revealed. The results reveal that the exact AFR is a set of linear inequalities, whose coefficients can be represented in binary code, and the complexity of the right side is linear with the number of EVs, making it highly conducive to programming calculations. Moreover, this paper proposes a simplified practical AFR based on the exact AFR, which reduces computational complexity. Numerical simulation cases demonstrate that the accuracy of this simplified approach is still higher than that of existing methods.