The proliferation of poor power factor loads can deteriorate the network due to their negative
impacts. In this research, a power factor conditioning of PCC is presented as another role of pulse width
modulation rectifier. The main purpose of PWM rectifier is to adjust and regulate the output DC-voltage with
low harmonic distortion of AC-source current. If inductive loads connected to same PCC, the PWM rectifier
can also compensate for load reactive power. These two functions of PWM rectifier can improve overall system
power factor and decrease added cost elaborated with equipment required for compensation. The proposed
control scheme is based on d-q theory in which transformation from abc to d-q frames is carried out for both
load and converter currents. Quadrature portion of load current, which represents load reactive power, will be
inserted in current controller with negative phase to compensate for reactive power and improve poor power
factor. The proposed control algorithm is realized by a low-cost 80C196KC microcontroller which provides
multi-functions adequate for practical system implementation. Inductive load emulation is presented by a threephase induction motor due to its widespread applications and variable power factor at different mechanical
loads. |
