Peak current-controlled CRM flyback PFC converter with square of line voltage-compensated primary current envelope

A peak current control technique for a flyback power factor correction (PFC) converter operating in critical conduction mode (CRM) is proposed. By using the square of the line voltage to compensate the peak current envelope of the primary current, the input current distortion of the traditional peak current-controlled CRM flyback PFC converter can be eliminated, and the unity power factor and low total harmonic distortion (THD) can be obtained. The operating principles and characteristics of the proposed peak current-controlled CRM flyback PFC converter are analysed. Experimental results of a 30 W prototype show that the power factor and THD of the proposed peak current-controlled CRM flyback PFC converter are better than those of the traditional peak current-controlled CRM flyback PFC converter.