Flexibility-constrained operation scheduling of active distribution networks

Regarding the variability of renewable energy sources (RESs), especially in the operation time periods, their high penetration faces the net load pattern of the power system with a major ramp rate challenge. Although employing a market-based mechanism by the independent system operator (ISO) can address this challenge, it may not be possible to handle this challenge in all networks. In such networks, the required flexibility can be supplied through decreasing the ramp rate of the purchased power of distribution companies (Discos) from the market since their net load has an important impact on the system's net load. Therefore, a flexibility-constrained operation problem for the distribution networks with distributed energy resources (DERs) and microgrids (MGs) is proposed in this paper to decrease the ramp-rate of the Disco's purchased power from the market. This problem is formulated using a bi-level two-stage stochastic model where the problem of the Disco and the MGs are modeled as the upper-level and lower-level problems, respectively. The proposed model is applied to the IEEE 33-bus standard test network with three MGs. The results show the effectiveness of the proposed model to decrease the ramp-rate of the Disco's purchased power from the market.

Automated summary

This study proposes a solution to the flexibility-constrained operation problem in distribution networks by reducing the ramp-rate of purchased power from the market by distribution companies, which enhances system stability and reliability. The effectiveness of the proposed model is demonstrated in a test network with three microgrids, showing a successful decrease in the ramp-rate of purchased power.