Power converter based method for suppressing power capacitor harmonic current

Review, Properties, and Synthesis of Single-Switch Non-Isolated DC-DC Converters with a Wide Conversion Range

“…One can properly integrate two cascaded converters relying on one active switch each using the so-called graft technique, considering the four possible arrangements described in [13,27] and shown in Figure 5. This concept enables the derivation of small-signal models for single-stage topologies based on basic converter units [31] and assessing their operation in discontinuous conduction mode (DCM) [32].…”

“…(a) Configurations I and II correspond to common source-source and common draindrain connections, respectively, while configurations III and IV consist of common drainsource and common source-drain connections, respectively. According to [13], the two active switches in each possible combination can be replaced with an arrangement composed of one single active switch and two diodes, yielding the corresponding circuits represented in Figure 6, where "D" and "S" stand for the drain and source terminals of a MOSFET, respectively. Configurations I and II correspond to common source-source and common drain-drain connections, respectively, while configurations III and IV consist of common drain-source and common source-drain connections, respectively.…”

“…Configurations I and II correspond to common source-source and common drain-drain connections, respectively, while configurations III and IV consist of common drain-source and common source-drain connections, respectively. According to [13], the two active switches in each possible combination can be replaced with an arrangement composed of one single active switch and two diodes, yielding the corresponding circuits represented in Figure 6, where "D" and "S" stand for the drain and source terminals of a MOSFET, respectively. Now, let us consider the cascaded buck-boost/buck converter shown in Figure 4 as an example.…”

“…As previously mentioned, the graft scheme proposed in [13] allows for deriving single-switch converters as long as two or more switches share a common connection node. In this sense, it is possible to obtain multistage single-switch non-isolated DC-DC converters based on cascade stages in terms of a modular approach, which has not been presented in the literature before.…”

“…In fact, such topologies consist of the cascade association of two conversion stages, yielding redundant power processing and low efficiency. However, the concept that allows for deriving single-switch structures from cascaded converters whose active switches share a common node was only formalized in [13] in terms of the graft scheme.…”