Analysis of single switch delta-sigma modulated pulse space modulation PFC converter effectively using switching power device

With recent advances of semiconductor switching power devices, high frequency switching mode power converters are able to be realized. In these converters, the pulse width modulation (PWM) technique is widely used, but by using this control scheme, large peak noise spectra appear with odd interval of carrier frequency. Therefore, there are problems to keep the regulation of EMI noise. By the way, to improve input power factor of AC source line, power factor correction (PFC) converters are widely used. And the hysteresis control scheme is usually used for these PFC converters. But in this control scheme, lower and upper limit of switching frequency can not be determined. In this paper, the authors propose a novel delta-sigma modulated PFC converter utilizing pulse space modulation scheme. The authors improve delta-sigma modulation scheme and conventional PWM control scheme to reduce current rating of switching devices. And the authors implemented evaluation of comparing performance of proposed and conventional control scheme. The authors confirmed that proposed system can improve power factor and can reduce input current harmonics and noise level by exhibiting spread spectrum nature. And the proposed scheme extinguishes noise peak spectra. Furthermore, by using current limiting control scheme, the proposed scheme can reduce current rating of switching power devices in spite of simple configuration circuit.