PQ-coupled difference equation model for power system load

In this paper, a second order PQ-coupled difference equation load model (PQ-DELM) is derived, which takes the interrelation between active and reactive currents into account. Load modeling is revealed to be a closed loop identification problem, and for the parameter estimation of the PQ-DELM an instrumental variable (IV) algorithm is put forward. The field test of actual load and the test in the laboratory validate the PQ-DELM and the IV algorithm.<
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