Multi-output rectifier
The combination of a center-tapped transformer and a full-bridge rectifier solves the problems of poor cross-regulation and high stress in multi-output DC-DC converters, achieves efficient utilization of the transformer secondary winding and low harmonic stress, and provides cost-effective dual voltage output.
Patent Information
- Application Number
- CN202380093491.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-07
- Filing Date
- 2023-12-07
- Publication Date
- 2025-09-19
AI Technical Summary
The existing technology has problems in multi-output DC-DC converters, such as poor cross-regulation, low secondary winding utilization, high stress, high cost, and sensitivity to transformer structure tolerance.
A combination of a center-tapped transformer and four rectifier components is used, connected through capacitors to form a full-bridge configuration to achieve two voltage outputs, one of which is twice the voltage of the other. The bidirectional conduction of the secondary winding and the energy exchange between the capacitors are utilized to simplify the transformer structure and improve efficiency.
It achieves maximum utilization of the transformer secondary winding, reduces sensitivity to transformer secondary imbalance, reduces harmonic stress, provides excellent cross regulation and cost-effectiveness, and simplifies the transformer structure.
Smart Images
Figure CN120677624A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a rectifier, ie, an electrical device designed to convert an AC voltage into a DC voltage. Background Art
[0002] Rectifiers are widely used, for example, but not exclusively, in the manufacture of isolated or non-isolated DC-DC converters.
[0003] Many such DC-DC converters may actually include a transformer having a primary side winding and a secondary side winding, a switching circuit coupled to the primary side winding and configured to convert an input DC voltage into a voltage wave, and a rectifier coupled to the secondary side winding to convert the voltage wave transmitted by the transformer into an output DC voltage.
[0004] In this context, it is sometimes useful and / or necessary for a converter to generate multiple voltage outputs using a single transformer.
[0005] To achieve this, several techniques are known which generally involve equipping the transformer with multiple secondary-side windings and coupling each secondary-side winding to a dedicated rectifier, such as a center-tapped full-wave rectifier, a full-bridge rectifier, or a voltage doubler rectifier.
[0006] However, these known techniques often suffer from poor cross regulation, low secondary winding utilization, high stress, high cost or high sensitivity to transformer structural tolerances. Summary of the Invention
[0007] It is an object of the present disclosure to address or at least actively mitigate one or more of the above-mentioned disadvantages.
[0008] Another object of the present disclosure is to achieve this goal by a simple, rational and relatively inexpensive solution.
[0009] These and other objects of the present disclosure are achieved by the embodiments of the present disclosure as defined in the independent claims.The dependent claims define preferred or particularly advantageous aspects of the embodiments.
[0010] In particular, an embodiment of the present disclosure provides a rectifier, comprising:
[0011] a center-tapped transformer having a secondary-side winding including a first terminal, a second terminal, and a center terminal,
[0012] rectifier components, each rectifier component including an anode, a cathode and capable of allowing current to flow from the anode to the cathode while preventing current from flowing in the opposite direction from the cathode to the anode, and
[0013] capacitors,
[0014] The rectifier component comprises:
[0015] a first rectifier component having an anode and a cathode, the anode of the first rectifier component being connected to a first terminal of the secondary winding of the center-tapped transformer, the cathode of the first rectifier component being connected to a first output terminal of the rectifier,
[0016] a second rectifier component having an anode and a cathode, the anode of the second rectifier component being connected to the second output terminal of the rectifier, the cathode of the second rectifier component being connected to the second terminal of the secondary side winding of the center-tapped transformer,
[0017] a third rectifier component having an anode and a cathode, the anode of the third rectifier component being connected to a first common node between the cathode of the second rectifier component and the second terminal of the secondary winding of the center-tapped transformer, the cathode of the third rectifier component being connected to a second common node between the cathode of the first rectifier component and the first output terminal of the rectifier,
[0018] a fourth rectifier component having an anode and a cathode, the anode of the fourth rectifier component being connected to a third common node between the anode of the second rectifier component and the second output terminal of the rectifier, the cathode of the fourth rectifier component being connected to a fourth common node between the anode of the first rectifier component and the first terminal of the secondary side winding of the center-tapped transformer, and
[0019] The capacitor comprises:
[0020] a first capacitor having a first terminal and a second terminal, the first terminal of the first capacitor being connected to the second common node, the second terminal of the first capacitor being connected to a fifth common node between a center terminal of the secondary winding of the center-tapped transformer and the third output terminal of the rectifier, and
[0021] A second capacitor has a first terminal and a second terminal, the first terminal of the second capacitor is connected to the fifth common node, and the second terminal of the second capacitor is connected to the third common node.
[0022] Like other multi-output rectifiers, the novel rectifier described above is capable of providing two voltage outputs or voltage rails of different values, represented, for example, by a first output terminal and a third output terminal.
[0023] However, the novel rectifier of the present disclosure has several advantages over known rectifiers.
[0024] For example, the novel rectifier produces two voltage outputs, one of which is substantially and / or always twice the other.
[0025] This is done using only one secondary winding (i.e., that of a center-tapped transformer), thereby simplifying the transformer, reducing its size and improving rectification efficiency.
[0026] Furthermore, due to the novel rectifier topology, both halves of the secondary side winding conduct current in every operating phase, ie during the positive and negative half cycles.
[0027] In effect, the two halves of the secondary winding swap their roles every half cycle.
[0028] In this way, the rectifier achieves at least one or more of the following:
[0029] Maximum utilization of the secondary winding of the transformer, e.g. to make the most efficient use of the transformer's output;
[0030] Low sensitivity to transformer secondary imbalance, e.g. this reduces the risk of uneven stress and performance issues due to unbalanced loads; and
[0031] Low harmonic stress in the secondary side winding.
[0032] In effect, continuous (or quasi-continuous) conduction of both halves of the secondary winding means that each half of the secondary winding conducts continuously and in a bipolar (bidirectional) manner, resulting in one or more waveforms with low harmonic content.
[0033] The novel rectifier also achieves excellent cross-regulation of the two voltage outputs or voltage rails because one is built on the other, and because the two halves of the secondary side winding swap roles every half cycle, there is no risk that one of the voltage outputs or voltage rails will drift relative to the other due to transformer imbalance.
[0034] Furthermore, where synchronous rectification is used, the rectifier components (transistors) are no longer strictly unidirectional and will allow energy to be exchanged, thereby achieving further voltage rebalancing between the two capacitors and therefore between the two voltage outputs or rails.
[0035] Last but not least, the novel rectifier is also quite cost-effective being able to provide two voltage outputs or voltage rails using a single center-tapped transformer and only four rectifier components (all having a voltage rating equal to the highest output value).
[0036] According to one aspect of the present disclosure, the one or more rectifier components may be diodes.
[0037] This aspect has the advantage of simplifying the novel rectifier and thereby reducing its cost.
[0038] According to another aspect of the present disclosure, one or more rectifier components may be transistors.
[0039] This aspect has the advantage of allowing a more complex control and regulation of the novel rectifier.
[0040] Another embodiment of the present disclosure provides an isolated or non-isolated power converter, such as a DC-DC power converter, comprising:
[0041] a switching circuit comprising at least one power switch, the switching circuit being configured to convert a DC voltage into a voltage wave, and
[0042] The novel rectifier described above, wherein the center-tapped transformer includes a primary side winding coupled to receive a voltage wave from the switching circuit.
[0043] This embodiment utilizes a novel rectifier, thereby achieving substantially the same advantages.
[0044] According to one aspect of this embodiment, the power converter may include a reactive circuit configured to achieve ZVS (zero voltage switching) of the power switch.
[0045] Thanks to this solution, the switching circuit can generate higher-frequency voltage waves with lower power losses.
[0046] According to another aspect, the reactive circuit may include an LLC resonant cavity configured to filter a voltage wave generated by the switching circuit before the voltage wave reaches a primary winding of a center-tapped transformer.
[0047] In this way, the input excitation of the rectifier can be very close to a sine wave, thereby reducing the harmonic stress in the primary and secondary windings of the center-tapped transformer.
[0048] Alternatively, the reactive circuit may include a resonant cavity of a class E amplifier configured to filter the voltage wave generated by the switching circuit before it reaches the primary winding of the center-tapped transformer.
[0049] Another aspect of this embodiment may provide for the power converter to further include a primary-side rectifier configured to convert an AC voltage to a DC voltage to be applied to the switching circuit; and may include a power factor correction circuit.
[0050] With the primary-side rectifier, the power converter can advantageously adopt an AC / DC power converter configuration. BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The present invention will now be described by way of examples with reference to the accompanying drawings.
[0052] Figure 1 FIG. 1 is a schematic diagram of a rectifier according to an embodiment of the present invention, showing its situation during a positive half cycle.
[0053] Figure 2 yes Figure 1 Schematic diagram of the rectifier, showing its condition during the negative half cycle.
[0054] Figure 3 is included Figure 1 Schematic representation of a rectifier converter.
[0055] Figure 4 and Figure 5 The conventional center-tapped rectifier and Figure 1 The current flows in both halves of the secondary winding of the rectifier. DETAILED DESCRIPTION
[0056] Figure 1 The rectifier 100 includes a transformer 105 having a primary side winding 110 and a secondary side winding 115 , which may be wound on a single core of magnetic material.
[0057] The primary side winding 110 includes a first end terminal 120 and a second end terminal 125 , which may generally be coupled to opposite terminals of an AC voltage input 130 .
[0058] The secondary winding 115 includes a first end terminal 135 , a second end terminal 140 , and a center terminal 145 connected to a midpoint of the secondary winding 115 .
[0059] Thus, the transformer 105 adopts a so-called “center-tapped transformer” topology.
[0060] The rectifier 100 also includes a plurality of rectifier components.
[0061] In the present disclosure, each rectifier component means an electrical component that includes at least two terminals, including a first terminal (also referred to as an "anode") and a second terminal (also referred to as a "cathode"), and is capable of allowing current to flow from the anode to the cathode while preventing the reverse flow of current from the cathode to the anode.
[0062] In the example shown in the figure, each rectifier component is embodied as a diode.
[0063] However, in other embodiments, one or more (or each) rectifier components may be embodied as a thyristor (eg a silicon controlled rectifier or SCR) or a transistor, preferably a field effect transistor, such as an IGBT, JFET, MOSFET or HEMT.
[0064] The component (ie, transistor) may have three terminals including a source, a drain, and a gate.
[0065] In this disclosure, the source may be considered the anode of a transistor, while the drain may be considered the cathode.
[0066] By applying a voltage to the gate of the transistor, the transistor is placed in a first operating state (saturation state) in which current is allowed to flow through the component, i.e. between the source (anode) and the drain (cathode), while removing the voltage places the transistor in a second operating state (blocking state) in which current is prevented from flowing through the component.
[0067] Thus, by appropriately controlling the voltage at the gate, the transistor can advantageously be operated in a manner emulating a diode or a thyristor.
[0068] Returning to the rectifier 100 , the rectifier components belonging thereto may include a first rectifier component 150 having an anode 155 and a cathode 160 , wherein the anode 155 is connected to the first end terminal 135 of the secondary winding 115 and the cathode 160 is connected to the first output terminal 500 of the rectifier 100 .
[0069] It should be noted that in the present disclosure, the term "connected" may mean that two terminals coincide with each other, or are connected by a single electrical conductor (e.g., a wire), or are connected by multiple conductors leading to a common electrical node so that they can be at substantially the same voltage, preferably with no other electrical components (e.g., switches, diodes, capacitors, resistors, inductors, etc.) interposed between them.
[0070] The rectifier component may further include a second rectifier component 165 having an anode 170 connected to the second output terminal 600 of the rectifier 100 and a cathode 175 connected to the second end terminal 140 of the secondary side winding 115 of the center-tapped transformer 105 .
[0071] The rectifier components may also include a third rectifier component 180 and a fourth rectifier component 195 .
[0072] The third rectifier component 180 has an anode 185 and a cathode 190, wherein the anode 185 is connected to a first common node 210 between the cathode 175 of the second rectifier component 165 and the second end terminal 140 of the secondary side winding 115, and the cathode 190 is connected to a second common node 215 between the cathode 160 of the first rectifier component 150 and the first output terminal 500 of the rectifier 100.
[0073] It should be noted that in the present disclosure, "a common node between two or more terminals" means an electrical node connected to these terminals in the above sense, that is, an electrical node that coincides with these terminals or is connected to these terminals through electrical conductors so that they can all be at basically the same voltage, preferably without other electrical components in between (such as switches, diodes, capacitors, resistors, inductors, etc.).
[0074] The fourth rectifier component 195 has an anode 200 and a cathode 205, wherein the anode 200 is connected to a third common node 220 between the anode 170 of the second rectifier component 165 and the second output terminal 600 of the rectifier 100, and the cathode 205 is connected to a fourth common node 225 between the anode 155 of the first rectifier component 150 and the first end terminal 135 of the secondary side winding 115 of the center-tapped transformer 105.
[0075] In practice, the first rectifier component 150 , the second rectifier component 165 , the third rectifier component 180 and the fourth rectifier component 195 are arranged in a full-bridge configuration.
[0076] The rectifier 100 further includes a reactive branch composed of capacitors. The reactive branch includes a first capacitor 230 and a second capacitor 245 .
[0077] The first capacitor 230 has a first end terminal 235 and a second end terminal 240, wherein the first end terminal 235 is connected to the second common node 215, and the second end terminal 240 is connected to the fifth common node 260 between the center terminal 145 of the secondary side winding 115 of the center-tapped transformer 105 and the third output terminal 550 of the rectifier 100.
[0078] The second capacitor 245 has a first end terminal 250 and a second end terminal 255 . The first end terminal 250 is connected to the fifth common node 260 , and the second end terminal 255 is connected to the third common node 220 .
[0079] Turning now to the output terminals of the rectifier 100 , the second output terminal 600 of the rectifier 100 may refer to a reference voltage (eg, but not necessarily, ground), while the first and third output terminals 500 , 550 may be connected to respective electrical loads (not shown).
[0080] In other words, the first electrical load may be connected in series between the first output terminal 500 and the second output terminal 600 , and the second electrical load may be connected in series between the third output terminal 550 and the second output terminal 600 .
[0081] The operation of the rectifier 100 is described as follows.
[0082] During the positive half cycle of the voltage generated by the AC voltage input 130, the current at the primary winding 110 of the center-tapped transformer 105 is as follows Figure 1 Flow as indicated by the arrows.
[0083] In this way, the secondary side winding 115 generates a positive voltage at the first end terminal 135, a reference (e.g., zero) voltage at the second end terminal 140, and an intermediate voltage at the center terminal 145, which is equal to approximately half the sum of the voltages at the first end terminal 135 and the second end terminal 140.
[0084] In fact, assuming V p is the voltage difference between the first terminal 120 and the second terminal 125 of the primary winding 110, and the voltage difference V between the first terminal 135 and the center terminal 145 of the secondary winding 115 is A , and the voltage difference V between the center terminal 145 and the second end terminal 140 B , which can be given by the following formula:
[0085]
[0086] where N p is the number of turns of the primary winding 110, N A is the number of turns of the secondary winding 115 between the center terminal 145 and the first end terminal 135, N B is the number of turns of the secondary winding 115 between the center terminal 145 and the second end terminal 140 .
[0087] Since N A Equal to N B (Transformer 105 is actually a center-tapped transformer), V A In fact, it is equal to V B (Assuming it is equal to V o ), so the first terminal 135 can be considered as a positive voltage +2V o , the second end terminal 140 can be considered as a zero (zero) voltage, and the center terminal 145 can be considered as a positive voltage +V o .
[0088] In this case, the first rectifier component 150 allows (or is controlled to allow) current to flow between the anode 155 and the cathode 160 (e.g., the diode is forward biased or the transistor is held in a saturated state), while the third rectifier component 180 prevents (or is controlled to prevent) current from flowing from the cathode 190 to the anode 185 (e.g., the diode is reverse biased or the transistor is held in a blocking state).
[0089] This forms a first closed path for current from the first end terminal 135 of the secondary winding 115 to the center terminal 145, thereby passing through the first capacitor 230, as shown in FIG. Figure 1 Indicated by the solid arrow in .
[0090] At the same time, the second rectifier component 165 allows (or is controlled to allow) current to flow between the anode 170 and the cathode 175 (e.g., the diode is forward biased or the transistor is held in a saturated state), while the fourth rectifier component 195 prevents (or is controlled to prevent) current from flowing from the cathode 205 to the anode 200 (e.g., the diode is reverse biased or the transistor is held in a blocking state).
[0091] This forms a second closed path for current flow from the center terminal 145 of the secondary winding 115 to the second end terminal 140, thereby passing through the second capacitor 245, as shown in FIG. Figure 1 Indicated by the dotted arrow in .
[0092] Thus, the first capacitor 230 and the second capacitor 245 are simultaneously equal to V o The voltage difference is charged.
[0093] During the negative half cycle of the voltage generated by the AC voltage input 130, the current at the primary winding 110 of the center-tapped transformer 105 flows in the reverse direction, as shown in FIG. Figure 2 Indicated by the arrow in .
[0094] In this way, the secondary side winding 115 generates a negative voltage at the first end terminal 135, a reference (e.g., zero) voltage at the second end terminal 140, and an intermediate voltage (e.g., negative) at the center terminal 145, which is equal to half the sum of the voltages at the first end terminal 135 and the second end terminal 140.
[0095] In fact, the polarity across the secondary winding 115 is opposite compared to the positive half cycle described above.
[0096] In this case, the first rectifier component 150 prevents (or is controlled to prevent) current from flowing between the cathode 160 and the anode 155 (e.g., the diode is reverse biased or the transistor is held in a blocking state), while the third rectifier component 180 allows (or is controlled to allow) current to flow from the anode 185 to the cathode 190 (e.g., the diode is forward biased or the transistor is held in a saturated state).
[0097] This forms a first closed path for the current from the second end terminal 140 of the secondary winding 115 to the center terminal 145, thereby passing through the first capacitor 230, as shown in FIG. Figure 2 Indicated by the dotted arrow in .
[0098] At the same time, the second rectifier component 165 also prevents (or is controlled to prevent) current from flowing between the cathode 175 and the anode 170 (e.g., the diode is reverse biased or the transistor is held in a blocking state), while the fourth rectifier component 195 allows (or is controlled to allow) current to flow from the anode 200 to the cathode 205 (e.g., the diode is forward biased or the transistor is held in a saturation state).
[0099] This forms a second closed path for current from the center terminal 145 of the secondary winding 115 to the first end terminal 135 and thereby through the second capacitor 245, as shown in FIG. Figure 2 Indicated by the solid arrow in .
[0100] Thus, the polarity across the first capacitor 230 and the second capacitor 245 remains the same as in the positive half cycle, and both capacitors are still simultaneously charged at a voltage equal to V o The voltage difference is charged.
[0101] In view of the above, using a single center-tapped transformer 105 , the rectifier 100 can effectively provide two voltage outputs or rails, represented, for example, by the first output terminal 500 and the third output terminal 550 , where one voltage output is reliably twice the other.
[0102] In practice, the first output terminal 500 of the rectifier 100 effectively provides (eg, to a load connected thereto) a voltage equal to 2V. o The rectified voltage of the third output terminal 550 is effectively provided (eg, to a load connected thereto) with a voltage equal to V o of the rectified voltage.
[0103] The rectifier 100 disclosed above may advantageously (but not exclusively) be included in an isolated or non-isolated power converter 400. Figure 3 An example of this is schematically shown in .
[0104] In this case, the AC voltage input 130 may be embodied as (or replaced by) a switching circuit 405 configured to convert a DC voltage (eg, provided by the DC voltage input 410 ) into a voltage wave.
[0105] In some embodiments, the DC voltage input 410 may be, for example, a battery.
[0106] In other embodiments, the DC voltage input 410 may be a circuit including a primary-side rectifier 415 configured to rectify the AC voltage provided by the AC voltage input 420 , thereby configuring the converter 400 as an AC / DC power converter.
[0107] The AC voltage input 420 may be any AC voltage source, such as a public power distribution grid (eg, 230 V and 50 Hz), to which the primary-side rectifier 415 may be coupled (eg, via an electrical plug).
[0108] The primary side rectifier 415 may have any topology and / or configuration, such as, but not exclusively, a diode bridge, a single diode, a coupled dual diode, or any type of synchronous rectifier.
[0109] Additionally, block 415 may also include a power factor correction circuit (PFC), either passive or active (eg, but not limited to, Boost PFC).
[0110] Turning now to the switching circuit 405, the circuit generally includes at least one power switch 425, such as a transistor (e.g., a BJT bipolar junction transistor, a FET field effect transistor, a MOSFET, a MESFET, a JFET, an IGBT, a HEMT, or others), and a driver for applying an electrical pilot signal to the power switch 425 that is capable of turning it on (i.e., putting it in a saturated state) and off (i.e., putting it in a blocking state).
[0111] For example, the switching circuit 405 may be embodied as an AC / DC switching converter of class D, class E, half-bridge, full-bridge, or any other topology, with any number of power switches 425 .
[0112] The switching circuit 405 may be coupled to apply the generated voltage wave to the primary side winding 110 of the rectifier 100 , either directly or through one or more reactive circuits.
[0113] For example, to generate a high frequency voltage wave with low power loss, the converter 400 may include a reactive circuit 430 , such as a resonant or fully resonant circuit, arranged to achieve ZVS (zero voltage switching) of the power switch 425 .
[0114] In other words, the reactive circuit 430 can be configured to reduce the voltage or current stress applied to the power switch (switch) 425 around all or part of the switching events (transitions of the power switch 425 from a blocking state to a saturation state, or vice versa), for example to achieve full or partial ZVS or ZCS.
[0115] The reactive circuit 430 may also be configured to also reduce (or ultimately substantially zero) the time derivative of the voltage or current applied to the power switch 425 when the power switch 425 switches from the blocking state to the saturation state or vice versa.
[0116] Through these strategies, the power loss of the switch(es) 425 is actively reduced.
[0117] The reactive circuit 430 may include (or be embodied as) an LLC resonant cavity 435 configured to receive the square wave voltage waveform generated by the switching circuit 405 and output a sinusoidal (or nearly sinusoidal) voltage waveform applied to the primary side winding 110 of the center-tapped transformer 105 .
[0118] In other words, LLC resonant cavity 435 and reactive circuit 430 may be embodied as a single circuit.
[0119] Alternatively, the resonant cavity 435 may be a resonant cavity of a class-E amplifier configured to filter the voltage wave generated by the switching circuit 405 before the voltage wave reaches the primary winding 110 of the center-tapped transformer 105 .
[0120] Depending on the specific topology of converter 400 , rectifier components 150 , 165 , 180 , and 195 (if embodied as transistors) may be driven in an ideal diode manner or using gate signals that are synchronized with converter operation.
[0121] In any case, using rectifier 100 in converter 400 , as well as any other circuit or device, has several advantages.
[0122] For example, the rectifier 100 enables maximum utilization of the secondary winding 115 of the center-tapped transformer 105 because both halves of the secondary winding 115 conduct current during each operating phase (ie, during both the positive and negative half cycles).
[0123] The fact that both halves of the secondary side winding 115 conduct continuously results in very low harmonic stress in the secondary side winding 115 , especially compared to conventional center tapped rectifiers.
[0124] In this regard, you can refer to Figure 4 A diagram showing the currents flowing in the two halves of the secondary winding of a conventional center-tapped rectifier, and a reference Figure 5 , which shows the current flowing in the two halves of the secondary side winding 115 of the rectifier 100.
[0125] Both diagrams were prepared considering that the input excitation of the primary side winding is very close to a sine wave (e.g. if the rectifier is used in a resonant converter, e.g. with an LLC resonant cavity) or a trapezoidal wave (e.g. if the rectifier is used in a conventional converter, e.g. without an LLC resonant cavity or the like).
[0126] like Figure 4 As shown, in the case of a classic center-tapped rectifier, the two halves of the secondary-side winding are conducted in a pulsed and unipolar manner (curves A and B) with a high harmonic content.
[0127] In the case of the rectifier 100 (see Figure 5 ), the quasi-continuous conduction of the two halves of the secondary side winding 115 means that each half conducts continuously and in a bipolar manner, and therefore has low harmonic content.
[0128] Furthermore, because both halves of the secondary side winding 115 (switching roles every half cycle) are used to rectify energy from two voltage outputs or rails, the rectifier 100 exhibits low sensitivity to transformer secondary imbalance.
[0129] The rectifier 100 also exhibits excellent cross-regulation of the two voltage outputs or voltage rails because one is built upon the other, and because the two halves of the secondary side winding 115 swap roles every half cycle, there is no risk that one voltage output or voltage rail will drift relative to the other due to transformer imbalance.
[0130] Furthermore, using synchronous rectification, the rectifier components (transistors) 150, 165, 180 and 195 are no longer strictly unidirectional and will allow energy to be exchanged, thereby achieving further voltage rebalancing between the two capacitors 230 and 245 and therefore between the two voltage outputs or voltage rails.
[0131] Last but not least, being able to provide two voltage outputs or rails using a single center-tapped transformer 105 and only four rectifier components 150 , 165 , 180 , and 195 , the rectifier 100 proves to be quite cost-effective.
[0132] This is also due to the fact that all rectifier components 150, 165, 180 and 195 have a voltage substantially equal to or slightly higher than the maximum output voltage (2V o ) voltage rating (breakdown voltage). In comparison, conventional solutions, such as the classic center-tapped rectifier, require rectifier components with a voltage rating typically greater than twice the maximum output (2*2V o ) voltage rating (breakdown voltage).
[0133] As an example, the proposed rectifier is applied to the frequency range of 50 KHz to 300 KHz. However, its adaptability extends to other implementations, potentially covering a wider spectrum from 20 KHz to 2 MHz.
[0134] Using this rectifier topology, a significant reduction in the size of the power transformer can be achieved compared to conventional implementations, for example a size reduction of approximately 40%.
[0135] Although one or more exemplary embodiments have been presented in the foregoing Summary of the Invention and Detailed Description, it should be understood that there are a large number of variations. It should also be understood that the exemplary embodiment or exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration in any way. On the contrary, the foregoing Summary of the Invention and Detailed Description will provide those skilled in the art with a convenient roadmap for implementing at least one exemplary embodiment, and it should be understood that various changes can be made to the function and arrangement of the elements described in the exemplary embodiments without departing from the scope set by the appended claims and their legal equivalents.
Claims
1. A rectifier (100), comprising: A center-tapped transformer (105) has a secondary winding (115) including a first terminal (135), a second terminal (140), and a center terminal (145). Rectifier components (150, 165, 180, 195), each rectifier component comprising an anode, a cathode and adapted to allow current to flow from the anode to the cathode while preventing reverse current flow from the cathode to the anode, and capacitors (230, 245), The rectifier component comprises: a first rectifier component (150) having an anode (155) and a cathode (160), the anode (155) of the first rectifier component (150) being connected to a first terminal (135) of the secondary winding (115) of the center-tapped transformer (105), the cathode (160) of the first rectifier component (150) being connected to a first output terminal (500) of the rectifier (100), a second rectifier component (165) having an anode (170) and a cathode (175), the anode (170) of the second rectifier component (165) being connected to the second output terminal (600) of the rectifier (100), the cathode (175) of the second rectifier component (165) being connected to the second terminal (140) of the secondary side winding (115) of the center-tapped transformer (105), a third rectifier component (180) having an anode (185) and a cathode (190), the anode (185) of the third rectifier component (180) being connected to a first common node (210) between the cathode (175) of the second rectifier component (165) and the second terminal (140) of the secondary winding (115) of the center-tapped transformer (105), and the cathode (190) of the third rectifier component (180) being connected to a second common node (215) between the cathode (160) of the first rectifier component (150) and the first output terminal (500) of the rectifier (100), a fourth rectifier component (195) having an anode (200) and a cathode (205), the anode (200) of the fourth rectifier component (195) being connected to a third common node (220) between the anode (170) of the second rectifier component (165) and the second output terminal (600) of the rectifier (100), the cathode (205) of the fourth rectifier component (195) being connected to a fourth common node (225) between the anode (155) of the first rectifier component (150) and the first terminal (135) of the secondary side winding (115) of the center-tapped transformer (105), and The capacitor comprises: a first capacitor (230) having a first terminal (235) and a second terminal (240), the first terminal (235) of the first capacitor (230) being connected to the second common node (215), the second terminal (240) of the first capacitor (230) being connected to a fifth common node (260) between a center terminal (145) of the secondary winding (115) of the center-tapped transformer (105) and a third output terminal (550) of the rectifier (100), and a second capacitor (245) having a first terminal (250) and a second terminal (255), wherein the first terminal (250) of the second capacitor (245) is connected to the fifth common node (260) and the second terminal (255) of the second capacitor (245) is connected to the third common node (220).
2. The rectifier (100) according to claim 1, wherein One or more of the rectifier components (150, 165, 180, 195) is a diode.
3. The rectifier (100) according to claim 1 or 2, wherein: One or more of the rectifier components (150, 165, 180, 195) are transistors.
4. A power converter (400), comprising: A switching circuit (405) comprising at least one power switch (425), wherein the switching circuit (405) is configured to convert a DC voltage into a voltage wave, and The rectifier (100) of any one of the preceding claims, wherein the center-tapped transformer (105) comprises a primary side winding (110) coupled to receive a voltage wave from the switching circuit (405).
5. The power converter (400) of claim 4, comprising a reactive circuit (430) configured to achieve ZVS of the power switch (425).
6. The power converter (400) according to claim 5, wherein: The reactive circuit (430) includes an LLC resonant cavity (435) configured to filter the voltage wave generated by the switching circuit (405) before the voltage wave reaches the primary side winding (110) of the center-tapped transformer (105).
7. The power converter (400) according to claim 5, wherein: The reactive circuit (430) includes a resonant cavity (435) of a class E amplifier, wherein the resonant cavity (435) is configured to filter the voltage wave generated by the switching circuit (405) before the voltage wave reaches the primary side winding (110) of the center-tapped transformer (105).
8. The power converter (400) according to any one of claims 4 to 6, further comprising: A primary-side rectifier (415) configured to convert an AC voltage into a DC voltage to be applied to the switching circuit (405); and may include a power factor corrector circuit.