New power flow method with controls and limits representation by nonlinear programming techniques

• Grant number: 06/01634-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2006
• End date: July 31, 2007
• Field of knowledge: Engineering - Electrical Engineering - Power Systems
• Principal Investigator: Carlos Alberto de Castro Junior
• Grantee: Adriana Scheffer Quintela Ferreira
• Host Institution: Faculdade de Engenharia Elétrica e de Computação (FEEC). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The main goal of this research work is to study and implement a power flow computer program in which the action and limits of control equipment as well as other operational limits are taken into account via nonlinear programming techniques. The consideration of controls and limits will be made through the alternate adjustment technique, which can be easily incorporated to existing load flow computer programs based on Newton's and decoupled methods. The innovation consists in updating the control variables through a problem to be optimized so that the interactions (and occasional conflicts) among the controls are considered, since the contribution of the controls that affect the variable to be controlled will be fully taken into account. The reactive power limits of generation buses and consequently the specified voltages will be maintained within the appropriate range through this optimization methodology, without the need of bus type switching. This feature can be particularly interesting for the decoupled methods, since bus type switching are avoided, and new factorizing of the network matrices are not needed. Thus the control strategies will be considered in each load flow iteration, and the operational limits of the components of power system will be maintained. After the load flow convergence, a feasible power system operational state is obtained and it is as close as possible to the actual operation point. An evaluation of the potential utilization of this load flow program in a real time operation environment is also intended. Thus, the algorithm to be developed is intended to be an important tool to assist in the operation and the operation planning of power systems. (AU)