Abstract
An isolated step-up converter having first and second stages is described herein. The second stage can provide either DC or AC output based on the various topologies described. Resonance inductors and capacitors are used and tuned to a commutation frequency in some embodiments. Capacitors and inductors are also used in the first stage.
Claims
1. A step-up converter having first and second isolated stages, the first isolated stage comprising: a DC power source; a first inductor having a first terminal connected to the DC power source and a second terminal connected to a first terminal of a first capacitor; a second terminal of the first capacitor connected to a first terminal of a primary stage of a transformer; a second inductor having a first terminal connected to the DC power source and a second terminal connected to a first terminal of a second capacitor; a second terminal of the second capacitor connected to a second terminal of the primary stage of the transformer; a first switch having a first terminal connected to the second terminal of the first inductor and to the first terminal of the first capacitor, the first switch having a second terminal connected to ground; a second switch having a first terminal connected to the second terminal of the first capacitor and to the first terminal of the primary stage of the transformer, the second switch having a second terminal connected to ground; a third switch having a first terminal connected to the second terminal of the second inductor and to the first terminal of the second capacitor, the third switch having a second terminal connected to ground; and a fourth switch having a first terminal connected to the second terminal of the second capacitor and to the second terminal of the primary stage of the transformer, the fourth switch having a second terminal connected to ground.
2. The step-up converter of claim 1 further comprising: at least one of the first, second, third, or fourth switches being bidirectional.
3. The step-up converter of claim 1 further comprising: the fourth switch being bidirectional.
4. The step-up converter of claim 1 wherein the second isolated stage comprises: a first diode having a first terminal connected to a first node, and a second terminal connected to a second node; a second diode having a first terminal connected to the second node, and a second terminal connected to a third node; a secondary transformer stage having a first terminal connected to the second node, and a second terminal connected to a first terminal of a resonant inductor; a second terminal of the resonant inductor connected to a second terminal of a first resonant capacitor, and to a first terminal of a second resonant capacitor; a first terminal of the first resonant capacitor connected to the first node; and a second terminal of the second resonant capacitor connected to the third node; whereby a load can be connected between the first and third nodes.
5. The step-up converter of claim 4 further comprising: the resonant inductor and first and second resonant capacitors having a resonant frequency equal to a commutation frequency.
6. The step-up converter of claim 1 wherein the second isolated stage comprises: a fifth switch having a first terminal connected to a first node, and a second terminal connected a first terminal of a sixth switch; the second terminal of the sixth switch connected to a second node; a seventh switch having a first terminal connected to the second node, and a second terminal connected to a first terminal of an eighth switch; a second terminal of the eighth switch connected to a third node; a secondary transformer stage having a first terminal connected to the second node, and a second terminal connected to a first terminal of a resonant inductor; a second terminal of the resonant inductor connected to a second terminal of a first resonant capacitor, and to a first terminal of a second resonant capacitor; a first terminal of the first resonant capacitor connected to the first node; a second terminal of the second resonant capacitor connected to the third node; and a third capacitor connected between the first and third nodes; whereby a load can be connected between the first and third nodes.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features of the inventive embodiments will become apparent to those skilled in the art to which the embodiments relate from reading the specification and claims with reference to the accompanying drawings, in which:
[0021] FIG. 1 depicts a schematic diagram of one embodiment of the present invention;
[0022] FIG. 1A depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0023] FIG. 2 depicts a schematic diagram of one embodiment of the present invention;
[0024] FIG. 3 depicts a schematic diagram of a prior art topology (Topology N1);
[0025] FIG. 4 depicts a schematic diagram of a prior art topology (Topology N2);
[0026] FIG. 6A depicts a waveform diagram for time t1 to t2 (50% duty cycle);
[0027] FIG. 6B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0028] FIG. 5A depicts a waveform diagram for time t0 to t1 (50% duty cycle);
[0029] FIG. 5B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0030] FIG. 7A depicts a waveform diagram for time t0 to t1 (40% duty cycle);
[0031] FIG. 7B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0032] FIG. 8A depicts a waveform diagram for time t1 to t2 (40% duty cycle);
[0033] FIG. 8B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0034] FIG. 9A depicts a waveform diagram for time t2 to t3 (40% duty cycle);
[0035] FIG. 9B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0036] FIG. 10A depicts a waveform diagram for time t3 to t4 (40% duty cycle);
[0037] FIG. 10B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0038] FIG. 11A depicts a waveform diagram for time t0 to t1 (60% duty cycle);
[0039] FIG. 11B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0040] FIG. 12A depicts a waveform diagram for time t1 to t2 (60% duty cycle);
[0041] FIG. 12B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0042] FIG. 13A depicts a waveform diagram for time t2 to t3 (60% duty cycle);
[0043] FIG. 13B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0044] FIG. 14A depicts a waveform diagram for time t3 to t4 (60% duty cycle);
[0045] FIG. 14B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0046] FIG. 15 depicts a graph showing the complexity of DC-DC converter is inversely proportional to Vin/Iin;
[0047] FIG. 1B depicts a schematic diagram of a simplified/representative view of FIG. 1;
[0048] FIG. 16A depicts a waveform diagram for an alternative embodiment;
[0049] FIG. 16B depicts a schematic diagram of a simplified/representative view of FIG. 16A;
[0050] FIG. 17A depicts a waveform diagram (50% duty cycle);
[0051] FIG. 17B depicts a waveform diagram (40% duty cycle); and
[0052] FIG. 17C depicts a waveform diagram (60% duty cycle).
DETAILED DESCRIPTION
[0053] FIG. 1 depicts one embodiment of the invention wherein a step-up converter 100 has first and second isolated stages, 101, 102, the first isolated stage comprises, a DC power source V1; a first inductor L1 having a first terminal 103 connected to the DC power source and a second terminal 104 connected to a first terminal 105 of a first capacitor C1; a second terminal 106 of the first capacitor C1 connected to a first terminal 119 of a primary stage 131 of a transformer Tr; a second inductor L2 having a first terminal 111 connected to the DC power source V1 and a second terminal 112 connected to a first terminal 113 of a second capacitor C2; a second terminal 114 of the second capacitor C2 connected to a second terminal 120 of the primary stage 131 of the transformer Tr; a first switch S1 having a first terminal 107 connected to the second terminal 104 of the first inductor L1 and to the first terminal 105 of the first capacitor C1, the first switch S1 having a second terminal 108 connected to ground; a second switch S2 having a first terminal 109 connected to the second terminal 106 of the first capacitor C1 and to the first terminal 119 of the primary stage 131 of the transformer Tr, the second switch S2 having a second terminal 110 connected to ground; a third switch S3 having a first terminal 115 connected to the second terminal 112 of the second inductor L2 and to the first terminal 113 of the second capacitor C2, the third switch S3 having a second terminal 116 connected to ground; and a fourth switch S4 having a first terminal 117 connected to the second terminal 114 of the second capacitor C2 and to the second terminal 120 of the primary stage 131 of the transformer Tr, the fourth switch S4 having a second terminal 118 connected to ground. In one embodiment, step-up converter 100 comprises at least one of the first, second, third, or fourth switches, S1, S2, S3, S4 respectively, being bidirectional. In one embodiment, step-up converter 100 comprises the fourth switch S4 being bidirectional.
[0054] FIG. 1 depicts one embodiment of the invention wherein the second isolated stage 102 comprises a first diode 133 having a first terminal 122 connected to a first node 135, and a second terminal 121 connected to a second node 136; a second diode 134 having a first terminal 138 connected to the second node 136, and a second terminal 139 connected to a third node 137; a secondary transformer stage 132 having a first terminal 123 connected to the second node 136, and a second terminal 124 connected to a first terminal 125 of a resonant inductor Lr; a second terminal 126 of the resonant inductor Lr connected to a second terminal 128 of a first resonant capacitor Cr1, and to a first terminal 129 of a second resonant capacitor Cr2; a first terminal 127 of the first resonant capacitor Cr1 connected to the first node 135; and a second terminal 130 of the second resonant capacitor Cr2 connected to the third node 137; whereby a load RL can be connected between the first and third nodes 135, 137. The second isolated stage 101 of FIG. 1 provides a DC voltage.
[0055] In one embodiment, the second isolated stage 102 comprises, the resonant inductor Lr and first and second resonant capacitors Cr1, Cr2, having a resonant frequency equal to a commutation frequency. FIG. 2 depicts one embodiment of the invention wherein the second isolated stage 200 comprises, a fifth switch S5 having a first terminal 204 connected to a first node 205, and a second terminal 203 connected a first terminal 202 of a sixth switch S6; the second terminal 201 of the sixth switch S6 connected to a second node 224; a seventh switch S7 having a first terminal 219 connected to the second node 224, and a second terminal 220 connected to a first terminal 221 of an eighth switch S8; a second terminal 222 of the eighth switch S8 connected to a third node 218; a secondary transformer stage 211 having a first terminal 210 connected to the second node 224, and a second terminal 212 connected to a first terminal 213 of a resonant inductor 225; a second terminal 214 of the resonant inductor 225 connected to a second terminal 207 of a first resonant capacitor Cr1′, and to a first terminal 216 of a second resonant capacitor Cr2′; a first terminal 206 of the first resonant capacitor connected to the first node 205; a second terminal 217 of the second resonant capacitor connected to the third node 218; and a third capacitor 215 connected between the first and third nodes 205, 218; whereby a load RL can be connected between the first and third nodes 205, 218. The second isolated stage 200 of FIG. 2 has an AC output across the load whereas the second isolated stage 101 of FIG. 1 provides a DC voltage.
[0056] While this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that changes in form and detail thereof may be made without departing from the scope of the claims of the invention.
