Interleaved high step‐up zero‐voltage‐switching boost converter with variable inductor control

Abstract

An interleaved high step-up zero-voltage-switching boost converter is proposed in this study. The operating principle and voltage gain ratio of the proposed converter are presented. The variable inductor control method is used to regulate the output voltage and to achieve a high-voltage gain. The design procedure of the variable inductor with a double E core is also presented in detail. Finally, a 40 W prototype with a 12 V input and 100 V output is built to verify the consistency of the theory analysis. The highest efficiency measured is 84.5%.

Analysis and Design of the Soft-Switched Clamped-Resonant Interleaved Boost Converter

“…Changing the turn-on interval of the two switches does not modify the duration of these two intervals, labeled D a and D b in Fig. 3, thus impeding the use of the duty-cycle (at constant switching frequency) as the control variable (the same conclusion can be found in [16] and [20]).…”

“…Paper [16] proposes a variable frequency control, while papers [17]- [19] claim the possibility of using the duty-cycle to control the output voltage at constant switching frequency, which is not possible, as it will be proved in the converter analysis reported in the following sections. This fact was also demonstrated, not only in [16], but also in [20]. The latter presents an interleaved boost converter with a symmetrical voltage doubler rectifier, that employs a variable inductor, as resonant element, to control the converter gain at constant switching frequency, although with a rather limited regulation capability.…”

“…2. Differently from the previous works [15]- [20], the input current is not assumed constant, thus allowing to select the input inductors value based on the desired total input current ripple, that will be reduced as a result of the interleaved operation. In the following, current i L (t) stands for i Lb (t) and the same equations apply to i La (t) in the second switching half period.…”

“…All currents have a zero average value, as consequence of a zero output power. The resonant voltage waveform is described by (5), and the sub-interval duration is given by (J C0nl = J L0nl -J m0nl ): (16) which gives (17) The peak of the resonant voltage occurs exactly at θ c /2 and, in order to have a zero energy transfer to the output, the condition that needs to be satisfied is (18) Using (18) and (16) into (5), the following condition is found: Assuming the inductance ratio λ is known, from (19) angle θ c is found, and from (16) the initial condition J C0nl is calculated as (20) Using (3) and (16) together with the condition j m (θ c /2) = 0, the initial condition J m0nl results: (21) Then, the input inductor current initial value is derived from (22) The switching frequency, in this situation, reaches its maximum value given by (23) where the overlapping angle θ ov = ω r T ov is calculated imposing a steady-state condition for the input inductor current. In fact, from Fig.…”

Linear open circuit voltage‐variable step‐size‐incremental conductance strategy‐based hybrid MPPT controller for remote power applications

“…The efficiency of flyback converter is further increased by choosing soft switching techniques using auxiliary circuits. Soft switching reduces the switch voltage or current to zero just before the 'On' or 'Off' of the switches, thereby reducing the switching losses of converter [20].…”