Frequency-Constrained Economic Dispatch Considering Demand-Side Resource Aggregation

The integration of a high proportion of renewable energies into the power grid significantly reduces the inertia level of the power system and brings foreseeable frequency security risks. In order to deal with this problem, it is necessary to explore the regulation potential of flexible resources on the demand side and work with traditional frequency regulation units to ensure the frequency stability of the system. This paper proposes a frequency-constrained economic dispatch (FCED) model. First, considering that incorporating demand-side load resources into frequency regulation will significantly increase the complexity of frequency dynamics, different types of frequency response resources are modeled and aggregated. Then, the frequency dynamic process in different time intervals is depicted, and the frequency security constraints corresponding to each time interval are derived. Finally, the traditional security-constrained economic dispatch (SCED) is combined with frequency security constraints to obtain a novel FCED model. The results of the case studies based on the IEEE 30-Bus system show that the FCED model proposed in this paper can schedule load resources to maintain the frequency security of the system after contingencies occur and ensure the economic and stable operation of the system.

I. Introduction

With the rapid development of new power systems, the power grid is transitioning towards a high proportion of renewable energies and power electronic devices [1]. However, this shift has impacted the inertia of the power system, previously dominated by traditional generators, and further affected the frequency stability of the system, bringing operational risks to the system [2].