Table 1 Assessment of non-isolated bidirectional DC-DC converters

Basic buck and boost Fig. 7a

\(\frac{1}{1 - D}\)

1

2

2

Low number of elements; Discontinuity of input current

Photovoltaic system and uninterrupted power supply

Buck–boost Fig. 7b

\(\frac{ - D}{{1 - D}}\)

2

2

2

Negative output voltage, capable to step-up/Step-down the voltage

Electric vehicle

Cuk Fig. 7c

\(\frac{ - D}{{1 - D}}\)

2

3

4

Continuous input and output currents

Battery storage system

Sepic/Zeta Fig. 7d

\(\frac{D}{1 - D}\)

2

3

2

Positive output voltage and reduced current ripple using an auxiliary circuit

Distributed power system

Cascaded Fig. 7e

\(\frac{1}{1 - D}\)

1

2

4

Higher voltage gain and lower current stress

Electric vehicle and smart grid

Switched capacitor Fig. 7f

2

0

3

4

Low size and weight since no inductor, continuous input current

Distributed energy resources

Interleaved Fig. 7g

\(\frac{1}{1 - D}\)

n = 2

2

2n = 4

Low switching frequency current ripple and smaller EMI filter required

High-power applications and distributed energy storages

Multilevel Fig. 7 (h)

n = 3

0

n(n + 1)/2 = 6

n(n + 1) = 12

Low size and weight since no inductor, self-voltage balancing

Dual voltage architecture (Automotive systems)