Recently, Three-phase AC/DC converters are widely used in industrial machines due to performance and low cost. Most of AC/DC Converters are power electrical bridge circuit using rectifiers with phase control and line commutation converter. But the important disadvantage of classical rectifiers include power regeneration capabilities, lower harmonics of input current, high power factor. For the reason, three-phase AC/DC PWM converter has been more popular in industry application since it is appropriate for reduced reactive power, low harmonic input current, sinusoidal input current wave form, high total power factor, controlled DC link voltage, small filter, bidirectional power transmission.
The PWM converter used in control method and the electrical drive application are still developed. Although These systems can be mostly used for control in many line voltage sensor and phase current sensor, the systems have included increasing cost and high harmonic weakness. To eliminate the line voltage sensor, this study tend to voltage angle information that is obtained by sensorless control method using only the current sensor.
The sensorless control methods are included in variable control such as sliding mode control, adaptive control, state observer control. The virtual flux oriented vector control is improved that These control method was adapted for harmonics and noise in the past.
This paper investigates a new sensorless control method appling a virtual flux oriented vector control without the line voltage sensor. The output DC voltage is controlled by applying the kalman filter algorithm for the flux estimation and the line voltage phase is obtained by using estimate flux. The proposed system implement PFC algorithm to estimate synchronization phase with the virtual flux, so that it in this paper has strong advantage of the instantaneous DC output voltage in the variable region. Because the DC output voltage in a load variation has advantages which can be controlled with high precision, it is highly suitable for multi-output variable DC power supply. The active and reactive powers estimation are performed based on the estimated flux and phase angle. The performance of the proposed algorithm is verified through simulation and experiment. It shows that the DC output voltage is controlled by using virtual flux based on Kalman Filter.