Método para limitação de índices de desequilíbrio de máquinas elétricas trifásicas em sistemas de distribuição

Abstract

This work proposes a multiphase optimal power flow methodology for limiting imbalances of terminal voltages and currents required or injected into three-phase rotating machines, generators or motors, with special application to disperse generators connected to distribution systems. The equipment modelling is based on current injection method in rectangular coordinates. The methodology was implemented and the proposed computational tool was developed with Matlab® and Lingo® softwares. For limiting the imbalance to acceptable levels as determined by current standards and equipment manufacturers, shunt capacitor banks were used in the of the machines terminals. The methodology is be able to indicate in which phase the capacitors must be connected and their respective powers. New possibilities for modeling electrical machines are proposed as were, including addressing internal features of this equipment. Among these possibilities are modeling by specification of voltage difference between nodes (amplitude and angle) with the possibility of representing the internal impedances of the machine, modeling by specification of voltage amplitude between nodes and modeling with voltage amplitude and active power with operating constraints.