The Effect of Different Representations of Power Transducers on the Power Factor Control in Distributed Generators under Unbalanced Conditions

Due to the trend of integration of dispersed generation into the electrical systems, in many countries it is possible to find synchronous generators directly connected to Distribution Power Systems (DPS). The Distributed Synchronous Generation (DSG) often employs an additional control loop to its excitation system: the Power Factor Controller (PFC). The objective of the PFC is to maintain the power factor at the terminal bus of the DSG close to one, so the DSG can inject mostly active power into the utility grid. However, little is known about its performance under unbalanced conditions, which are often encountered in DPS. Therefore, the need for more studies involving 3-phase simulation of DSG with PFC becomes evident. This work contributes to fill this gap, presenting some problems that might occur when instantaneous power transducers are used, under unbalanced conditions, to calculate the power factor value, which composes the feedback signal into the PFC.