A new technique to improve voltage controlled nodes (PV nodes) in the current injection Newton-Raphson power-flow analysis

Newton Raphson load flow based on current injection mismatches (CIM) is very efficient when all the buses are PQ buses. However, when PV buses exist, the performance of the method is affected due to the representation of additional equations for every PV node. Hence, the CIM is not reliable for solving transmission systems and found wide usage in distribution systems. The present paper describes a new representation for PV nodes by using a hybrid power flow formulation using current and power mismatches. The current and power equations are written in rectangular coordinates. The Jacobian matrix (2n×2n) has the same structure as the nodal admittance matrix. The PQ buses equation is developed based on current mismatches whereas PV buses equations are based on power mismatches. In this method, only one equation is required each PV bus. The initial results show that the algorithm offers good performance when it is compared with both the CIM method and the standard NR method.