DC-DC converter with complementarily driven switching elements
A DC-DC converter includes n number of first series circuits each including an inductor and a switching element and a second series circuit in which n number of rectifier elements are connected in series with a same rectification direction. When n=2, one end of the second series circuit is connected to a node between an inductor and a switching element in the first series circuit and the other end of the second series circuit is connected to one end of a smoothing capacitor and one end of a load. A node between an inductor and a switching element is connected to a node between the rectifier elements via a capacitor. The odd-numbered switching element and the even-numbered switching element in the order of connection to the second series circuit are complementarily driven.
1. A DC-DC converter comprising:
n number of first series circuits each including an inductor and a switching element, the n number of the first series circuits being connected in parallel between direct-current voltage input terminals, n being an integer that is greater than or equal to 2;
a second series circuit including n number of rectifier elements connected in series to have a same rectification direction, a first end of the second series circuit being connected to a node between the inductor and the switching element in one of the n number of the first series circuits; and
a switching control circuit that controls the switching elements of the n number of the first series circuits connected to the n number of the rectifier elements so that an odd-numbered switching element and an even-numbered switching element of the switching elements of the n number of the first series circuits in a connection order of the n number of the rectifier elements in the second series circuit are alternately turned on and off with no overlap; wherein
a node between the n number of the rectifier elements in the second series circuit and a node between the inductor and the switching element in a remaining (n−1) number of the first series circuits are connected via a capacitor;
a second end of the second series circuit is connected to one end of a smoothing capacitor and one end of a load.
2. The DC-DC converter according to claim 1 , wherein the switching elements of the n number of the first series circuits are field effect transistors.
3. The DC-DC converter according to claim 1 , wherein the rectifier elements of the second series circuit are field effect transistors and the switching control circuit drives the rectifier elements.
4. The DC-DC converter according to claim 3 , wherein each of the rectifier elements of the second series circuit and the switching element connected to an upstream side of the rectifier element in a connection order of the rectifier elements are complementarily driven.
5. The DC-DC converter according to claim 1 , wherein the rectifiers of the second series circuit include diodes connected in series to have a same rectification direction.
6. The DC-DC converter according to claim 1 , wherein the switching control circuit controls operation of the n number of the first series circuits and the second series circuit in a first state and in a second state which are alternately repeated.
7. The DC-DC converter according to claim 1 , wherein the switching control circuit controls operation of the n number of the first series circuits and the second series circuit such that a boosting chopper circuit is defined.
8. The DC-DC converter according to claim 6 , wherein the switching control circuit controls operation of the n number of the first series circuits and the second series circuit such that a voltage that is twice a voltage generated by the boosting chopper circuit is output.
9. The DC-DC converter according to claim 1 , wherein the switching control circuit controls operation of the n number of the first series circuits and the second series circuit such that a second alternating voltage is superimposed on a first alternating voltage to produce a resultant voltage that is smoothed to generate an output voltage.
10. The DC-DC converter according to claim 1 , wherein the n number of the first series circuits is two.
11. The DC-DC converter according to claim 1 , wherein the n number of the first series circuits is three.
12. The DC-DC converter according to claim 1 , wherein the second series circuit includes three diodes connected in series.
13. The DC-DC converter according to claim 1 , wherein the switching control circuit turns on and off the odd-numbered switching element and the even-numbered switching element of the switching elements of the n number of the first series circuits with a duty ratio of 50%.
14. The DC-DC converter according to claim 1 , wherein the DC-DC converter reverses a polarity of a voltage, boosts the voltage and outputs a resultant voltage.
15. The DC-DC converter according to claim 1 , wherein the switching control circuit controls operation of the n number of the first series circuits and the second series circuit such that a boosting chopper circuit with an inverting converter configuration is defined.
16. The DC-DC converter according to claim 3 , wherein the switching control circuit drives first and second groups of the rectifier elements in a complimentary manner.