Data-Driven Dynamic Equivalents for Power System Areas From Boundary Measurements

The paper describes an algorithm for parameter identification of a dynamic equivalent for an external subsystem, based solely on the available online measurements in boundary buses and branches. Static equivalent part is represented by equivalent impedances from boundary buses (ones that separate the internal and external subsystems) and calculated using the modified (minimum loss) radial, equivalent, and independent method. Parameter identification of synchronous generator (SG)-based equivalent (for predominantly production external areas), dynamic load (DL)-based equivalent (for predominantly load external areas), or (SG + DL)-based equivalent (for mixed external areas) in fictitious buses is performed by Levenberg-Marquardt weighted least-square nonlinear optimization, which minimizes the variances between available online measurements and transient responses of the reduced power system. The IEEE 14-bus and 441-bus real-world test systems are used to illustrate and test the proposed power system equivalent derivation technique.