Online and Look-Ahead Determination of the Renewable Admissible Region for Managing the Uncertainty of Renewables: Theory and Some Applications

An online Admissible Region for Renewable Power Injection (ADMIRE) is proposed and completely characterized. The concept of the ADMIRE seeks to quantify the amount of renewable energy that the power system can not only accommodate but also cause no security violations. The ADMIRE provides vital information regarding the system's ability to deal with renewable penetrations and their uncertainties. The ADMIREs of a current operating point or a look-ahead scheduled operating point are vital information for power system operators and reliability engineers in the control center. In this paper, the characterization and computation of the ADMIRE are developed under the framework of AC power flow models with detailed models of voltage control as well as physical and operational constraints. To tackle the computational challenges in characterizing and computing the ADMIRE, we develop a nonlinear dynamic system approach by building a completely stable dynamic system, termed the ADMIRE-quotient gradient system (QGS). It is then theoretically proven that the feasible region of the ADMIRE constraints is equivalent to the regular stable equilibrium manifold (RSEM) of the corresponding ADMIRE-QGS. Numerical validation of the derived characterization of the ADMIRE is performed on the 14-bus, 30-bus, and 1354-bus systems to show that the proposed ADMIRE-QGS-based method can exactly characterize the ADMIRE, and the ADMIRE can help to integrate the renewable uncertainty effectively.