Design and analysis of a single-phase low-frequency active power factor correction circuit: a symmetric trapezoidal current waveform approach

This paper focuses on the design and analysis of the single-phase Low-Frequency Active Power Factor Correction (LFAPFC) circuit. The LFAPFC circuit has several attractive features such as low electromagnetic interference, low switching frequency and ease of implementation when compared with the High-Frequency Active Power Factor Correction circuit. Moreover, its performance is much better than that of the Passive Power Factor Correction circuit. However, few of the previous studies focus on determining the values of major parameters of the LFAPFC circuit and their corresponding performance. To conduct an in-depth study on the LFAPFC circuit, this paper proposes a systematic design method based on analyzing the characteristics of a symmetric trapezoidal current waveform. Using the proposed method, output performance indices such as total harmonics distortion and power factor of the LFAPFC circuit can be estimated. In addition, the relationship among the output performance, inductance and conduction parameters of the power switch is derived and investigated. Using the proposed method, designers can determine suitable values of conduction parameters and inductance for specific applications. Computer simulations and real experiments are carried out to verify the effectiveness of the proposed method.