"CRIC", A New Active-Reactive Decoupling Process in Load Flows, Optimal Power Flows and System Control

Abstract A new process for active reactive decoupling in load flow computations, so-called "Constrained Reactive Implicit Coupling", or "CRIC", is presented. For active computations, as usual voltage magnitudes are assumed constant for reactive computations, the active power injections are assumed constant, and no longer the voltage phase angles, so that the corrections on reactive powers and voltage magnitudes do not disturb the results obtained in active corrections. Applications are possible for load flows, optimal power flows and real time control. For load flows, active reactive computations are faster than with a coupled Jacobian but accurate even for high loads; the load flow algorithms are extended in 3 directions : reactive only load flow; new bus status, an automatic bus status change, using the sparse inverse of the reactive Jacobian, allows to get a feasible solution for reactive generation very rapidly. With CRIC, optimal power flows may be completely decoupled; new sensitivity computations are described; a very fast reactive optimal power flow algorithm is presented. For real time control, CRIC will allow to take decisions for reactive powers without disturbing active power control.