Discretized Sampling based Current Sensorless Control of Single-Phase Totem-pole Power Factor Corrector

To achieve a cost-effective solution with enhanced power density for a typical totem-pole boost power factor corrector (TPFC) circuit, with a target to eliminate the input voltage-tracking current sensor, a novel discretized sampling based current sensorless control scheme is proposed in this paper. The proposed sensorless control scheme calculates the instantaneous current value based on the sensed input and output voltage data along with the designed value of circuit parameters with their parasitic components. A discretized sampling-based scheme is employed that obtains sensor information at every sampling instant, thus providing a smooth estimated current profile for further conditioning and processing. The proposed control scheme proves to be beneficial in terms of its ease of implementation, being robust to severe parameter changes, with its ability to support high frequency operation as compared to state of the art (SOA) techniques, while being able to eliminate one current sensor, thus targeting enhanced reliability. It also provides superior dynamic response when subjected to sudden/severe load changes, as explained in the stability analysis provided in this paper. To stress on its applicability in industrial application, a thorough comparison with several SOA methods has also been presented, to prove the superiority of the proposed control technique. A detailed simulation study is carried out to verify and elaborate on the specifics of the control scheme and the results portray 25% reduction in the response time as compared to the SOA approaches. Further, a proof-of-concept 800W prototype is fabricated to benchmark and evaluate the system overall performance.