Power converter
A DC/DC power converter has an input terminal, an output terminal, and a ground terminal. The DC/DC power converter includes two capacitors connected in series between the output terminal and the ground terminal, a boost converter having a first boost converter terminal connected to the input terminal, a second boost converter terminal connected to the output terminal, and a third boost converter terminal connected to a connection point between the capacitors, and a step-up converter having a first step-up converter terminal connected to the ground terminal, a second step-up converter terminal connected to the output terminal, and a third step-up converter terminal connected to the connection point.
1. A DC/DC power converter comprising:
an input terminal;
an output terminal;
a ground terminal;
two capacitors connected in series between the output terminal and the ground terminal;
a boost converter having a first boost converter terminal connected to the input terminal, a second boost converter terminal connected to the output terminal, and a third boost converter terminal connected to a connection point between the capacitors; and
a resonant converter having a first step up converter terminal connected to the ground terminal, a second converter terminal connected to the output terminal, and a third converter terminal connected to the connection point, wherein the resonant converter comprises:
a resonant network for equilibrating a voltage on the capacitors; and
a resonant capacitor connected between a first and a second internal node.
2. The DC/DC power converter according to claim 1 , wherein the resonant converter further comprises:
a resonance inductor connected between a third internal node and the third converter terminal;
a first switch connected between the first converter terminal and the first internal node;
a second switch connected between the first internal node and the third internal node;
a third switch connected between the third internal node and the second internal node; and
a fourth switch connected between the second internal node and the second converter terminal.
3. The DC/DC power converter according to claim 2 , wherein the resonant converter is configured to operate by alternately toggling between a first state in which the first and third switches are closed and the second and fourth switches are opened, and a second state in which the first and third switches are opened and the second and fourth switches are closed.
4. The DC/DC power converter according to claim 3 , wherein the resonant converter is configured to operate in a way that the first to fourth switches are switched with a duty cycle of approximately 50%.
5. The DC/DC power converter according to claim 4 , wherein the boost converter is configured to operate depending on an input voltage applied between the input terminal and the ground terminal.
6. The DC/DC power converter according to claim 5 , wherein the boost converter comprises a single phase including:
a boost inductor connected between the first boost converter terminal and a fourth internal node;
a fifth switch connected between the fourth internal node and the second boost converter terminal; and
a sixth switch connected between the fourth internal node and the third boost converter terminal.
7. The DC/DC power converter according to claim 2 , wherein the first to fourth switches and/or the fifth and sixth switches are formed as semiconductor switches.
8. The DC/DC power converter according to claim 2 , wherein the first to fourth switches and/or the fifth and sixth switches are controlled independently.
9. The DC/DC power converter according to claim 1 , wherein the boost converter is configured to operate depending on an input voltage applied between the input terminal and the ground terminal.
10. The DC/DC power converter according to claim 1 , wherein the boost converter comprises a single phase including:
a boost inductor connected between the first boost converter terminal and a fourth internal node;
a fifth switch connected between the fourth internal node and the second boost converter terminal; and
a sixth switch connected between the fourth internal node and the third boost converter terminal.
11. The DC/DC power converter according to claim 10 , being configured to:
open the fifth switch and close the sixth switch if the input voltage is lower than a first predetermined value (V 1 );
close the fifth switch and open the sixth switch if the input voltage is higher than a second predetermined value (V 2 ) which is greater than the first predetermined value (V 1 ); and
alternately toggle between a third state in which the fifth switch is opened and the sixth switch is closed, and a fourth state in which the fifth switch is closed and the sixth switch is opened, if the input voltage is in a range between the first predetermined value (V 1 ) and the second predetermined value (V 2 ), wherein the duty cycle is selected depending on the input voltage.
12. The DC/DC power converter according to claim 10 , being configured to operate the boost converter in a way that the boost inductor operates in boundary mode between a continuous conduction mode and a discontinuous conduction mode.
13. The DC/DC power converter according to claim 1 , wherein the boost converter comprises two or more phases, each phase including:
a boost inductor connected between the first boost converter terminal and a fourth internal node;
a fifth switch connected between the fourth internal node and the second boost converter terminal; and
a sixth switch connected between the fourth internal node and the third boost converter terminal.
14. The DC/DC power converter according to claim 13 , wherein one of the phases operates as a master phase and the remaining phases operate as slave phases which are phase synchronized with the master phase.
15. The DC/DC power converter according to claim 1 , wherein the two capacitors have the same capacitance value so that the resonant converter operates as a voltage doubler.
16. A method of operating a DC/DC power converter, comprising:
applying an input voltage (Vin) between an input terminal and a ground terminal of the DC/DC power converter; and
converting the input voltage via a boost converter connected to the input terminal, an output terminal of the DC/DC power converter, and a connection point between two capacitors that are connected in series between the output terminal and the ground terminal, and via a resonant converter connected to the output terminal, the ground terminal, and the connection point, wherein the resonant converter comprises:
a resonant network for equilibrating a voltage on the capacitors; and
a resonant capacitor connected between a first and a second internal node.
17. A double stage DC/AC power converter comprising:
a DC/DC power converter; and
a DC/AC power converter connected to an output terminal of the DC/DC power converter;
wherein the DC/DC power converter comprises:
two capacitors connected in series between the output terminal and the ground terminal;
a boost converter having a first boost converter terminal connected to the input terminal, a second boost converter terminal connected to the output terminal, and a third boost converter terminal connected to a connection point between the capacitors; and
a resonant converter having a first converter terminal connected to the ground terminal, a second converter terminal connected to the output terminal, and a third converter terminal connected to the connection point, wherein the resonant converter comprises:
a resonant network for equilibrating a voltage on the capacitors; and
a resonant capacitor connected between a first and a second internal node.
18. The double stage DC/AC power converter according to claim 17 , wherein:
the DC/AC power converter is a single-phase or multiple-phase DC/AC power converter; and/or
a DC voltage source having a variable output voltage is connected to an input terminal of the DC/DC power device.
19. The double stage DC/AC power converter according to claim 18 , wherein the DC voltage source having a variable output voltage is a device for electricity generation from renewable resources, preferably a photo-photo-voltaic device or a wind energy device.