| Abstract |
This paper describes the concept, the project and the practical construction of a high performance
25kW three-phase power factor correction (PFC) power supply purposed to supply a plasma ion
nitriding reactor plant. The power stage is built on an industrial IGBT three-phase bridge rectifier
module configured in a pulse width modulation (PWM) boost rectifier topology. A –850VDC pulsed
output voltage supplies the ion nitriding reactor by means of an electronic static switch, according to
programmed recurrence frequency and nitriding work cycle. This PFC power supply is endowed of
three independent circuits for power factor correction in order to attempt the Brazilian electrical
standard, regarding the power factor and the current harmonic injection level in the utility line. The
PFC preregulator stage uses the average current-mode control implemented by a PWM control
scheme. A dedicated microcontroller unit executes the supervision, the task management, the running
sequence and the main programming parameters as well as the protection function of associated
subsystems. Using an external microcomputer, a RS-232 serial input allows the remote programming
of the PFC power supply, the ion nitriding reactor supervisory and the overall industrial process
control. Nowadays, the equipment operates in the INCUBATEC in Natal – RN, Brazil. This paper
highlights the PWM boost rectifier, the PFC preregulator and the compensator loop circuit design. |
