Discrete-time one cycle control technique applied in single-phase PFC boost converter

DCM Boost PFC for High Brightness LED Driver Applications

“…Applying (25) and (20) to (24), the "no noticeable harm" criteria for C n can be formulated as follows:…”

“…However, when PFC enters DCM, the limited numeric resolution and, consequently, duty cycle errors of the digital controller appear as additional sources of instability. The problem of mode transition was resolved in [25] by though a mixed conduction mode (MCM) digital controller with a DCM detection technique to realize boost PFC operating in both CCM and DCM during AC line half-cycle, and resulted in an improved THD performance. Yet, the above solutions for the mode transition problem complicate the OCC controllers and so diminish its key advantage.…”

Improved One-cycle Control for Realizing AC/DC Power Factor Correction Boost Converter

“…Many reports have discussed the control of PFC AC/DC boost converters. (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) A conventional control method uses voltage outer and current inner loops to trace the input voltage, input current, and output DC voltage with the average current control method. (1) However, the control by this method is complex and requires many detection components, which increases the circuit volume, cost, and complexity, and UC3854 is typically used as the control chip.…”

“…(1) However, the control by this method is complex and requires many detection components, which increases the circuit volume, cost, and complexity, and UC3854 is typically used as the control chip. Another control method is one-cycle control, (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) which does not need to detect the input voltage and does not use a multiplier, but it only uses a trigger signal control of an integrator and compares a sawtooth wave with the current detesting value. Finally, the control is relatively simple through the set-reset (SR) flip-flop control converter duty cycle and can significantly reduce the circuit size and cost.…”

“…Conventional one-cycle control methods can be broadly divided into the following two categories: the first category uses the output DC voltage error to obtain a continuous count-down sawtooth wave to be compared with the measured inductance current and to determine the duty cycle of the converter switch (2)(3)(4)(5) with IR1155S typically used as the control chip. The second category uses the output DC voltage error to obtain a continuous count-up sawtooth wave to be compared with the measured inductance current and to determine the duty cycle of the converter switch.…”