Multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter

Abstract

The present invention discloses a multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter, which is composed of an N-stage high-ratio DC / DC converter and a reference-level converter, or includes a high-frequency compensation circuit; the N-stage high-ratio DC / DC converter is used to achieve high-ratio voltage conversion, and the reference-level converter is an isolated converter or a non-isolated converter, and its output terminal can output adjustable voltages of different polarities, or the converter is an independent external power supply; the positive and negative and high and low of the level value at the output terminal of the reference-level converter affect the voltage ratio of the N-stage high-ratio DC / DC converter. By adjusting this level value, the fluctuations and wide-range changes of the supply power voltage can be resisted; the high-frequency compensation circuit compensates for high-frequency power fluctuations. The present invention improves the traditional switched-resonant converter, realizes wide-range gain adjustment of the converter while increasing the voltage ratio of the converter, and ensures the stability of the output voltage on the load side; if a high-frequency compensation circuit is added, the dynamic response speed can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of DC / DC converters, and in particular to a multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter. Background Art

[0002] Currently, the server power supply generally adopts a 48V intermediate bus architecture, and this 48V is obtained by power conversion on the server motherboard. Existing technical solutions mostly adopt a two-stage voltage conversion architecture. First, it undergoes a voltage conversion to 12V, and then another voltage conversion to low voltages such as the required 3.3V and 1.2V. This two-stage voltage conversion will increase the system power loss, thereby reducing the system efficiency, and increase the system volume, thereby reducing the power density. Traditional switched resonant cavity converters require a large number of switching tubes to form a high-order DC / DC converter to achieve a high ratio, and generally, such high-ratio DC / DC converters are in an open-loop operation state without voltage regulation, and have poor immunity to input voltage fluctuations and load power fluctuations. Summary of the Invention

[0003] The purpose of the present invention is to overcome the disadvantages and deficiencies of the prior art, and provide a multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter. This converter is composed of an N-stage high-ratio DC / DC converter and a reference level converter, which reduces power loss and improves power supply efficiency, reduces the power supply volume and improves the power density. Compared with traditional switched resonant cavity converters, it reduces the volume and the number of devices used. The present invention adjusts the voltage value at the output end of the reference level converter, thereby adjusting the voltage ratio of the N-stage converter, achieving resistance to fluctuations and wide-range changes in the supply power voltage, realizing wide-range gain adjustment of the converter, and ensuring the stability of the output voltage on the load side.

[0004] To achieve the above purpose, the technical solution provided by the present invention is: a multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter, which is composed of an N-stage high-ratio DC / DC converter and a reference level converter. The N-stage high-ratio DC / DC converter is an N-stage converter composed of N transformation units, where N is an integer greater than or equal to 2, and it is a non-isolated converter for realizing high-ratio voltage conversion; the reference level converter is an isolated converter or a non-isolated converter, or the reference level converter is an independent external power supply;

[0005] The first transformation unit of the N-stage converter adopts a first type of basic transformation unit, and the other transformation units except the first stage adopt a first type of basic transformation unit or a second type of basic transformation unit. The parts included in both the first type of basic transformation unit and the second type of basic transformation unit are:

[0006] Input port;

[0007] Output port;

[0008] The first resonant cavity, including a first end and a second end;

[0009] The second resonant cavity, including a first end and a second end, the first end of the second resonant cavity is electrically connected to the output port;

[0010] The first half-bridge circuit, including a first end, a second end and a midpoint, the midpoint of the first half-bridge circuit is electrically connected to the first end of the first resonant cavity, the first end of the first half-bridge circuit is electrically connected to the input port, and the second end is electrically connected to the output port;

[0011] The second half-bridge circuit, including a first end, a second end and a midpoint, the midpoint of the second half-bridge circuit is electrically connected to the second end of the first resonant cavity, the first end of the second half-bridge circuit is electrically connected to the output port, and the second end is electrically connected to the ground port or the output end of the reference level converter;

[0012] The second end of the second resonant cavity of the first type of basic conversion unit is electrically connected to the ground port. The second type of basic conversion unit further includes:

[0013] The third half-bridge circuit, including a first end, a second end and a midpoint, the midpoint of the third half-bridge circuit is electrically connected to the second end of the second resonant cavity of the second type of basic conversion unit, the first end of the third half-bridge circuit is electrically connected to the output port of the lower-level conversion unit, and the second end is electrically connected to the ground port or the output end of the reference level converter;

[0014] The output port of the first-stage conversion unit in the N-stage converter is the output end of the N-stage high-ratio DC / DC converter, electrically connected to the positive pole of the load. The output ports of other conversion units except the first-stage conversion unit are electrically connected to the input port of the lower-level conversion unit. The input port of the Nth-stage conversion unit is the input end of the N-stage high-ratio DC / DC converter, electrically connected to the positive pole of the power supply; the ground port of the N-stage high-ratio DC / DC converter is at the same potential as the negative pole of the load and the negative pole of the power supply;

[0015] Except for the case where the reference level converter is an independent external power supply, the input end of the reference level converter is electrically connected to the input end of the N-stage converter, the positive pole of the power supply or the output port of any first type of basic conversion unit in the N-stage converter; the output end can output an adjustable voltage, and the level value of the adjustable voltage is positive, negative or zero potential; the second end of at least one stage of the second half-bridge circuit or the third half-bridge circuit in the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit are electrically connected to the output end of a reference level converter; the on and off times of the switching tube inside the reference level converter affect the voltage at the output end of the converter. Therefore, controlling the duty cycle of the switching tube can adjust the level value at the output end of the reference level converter;

[0016] The positive / negative and high / low values of the level at the output terminal of the reference level converter affect the voltage transformation ratio of the N-stage converter: when the voltage at the output terminal of the reference level converter is positive, the voltage transformation ratio of the N-stage converter will become smaller; when the voltage at the output terminal is negative, the voltage transformation ratio of the N-stage converter will become larger; the higher the voltage at the output terminal of the reference level converter, the smaller the voltage transformation ratio of the N-stage converter, and the lower the voltage at the output terminal, the larger the voltage transformation ratio of the N-stage converter; by adjusting the voltage transformation ratio of the N-stage converter, the fluctuations and wide-range changes of the power supply voltage can be resisted, the wide-range gain adjustment of the converter can be achieved, and the stability of the load output voltage can be ensured.

[0017] Preferably, the reference level converter is a non-isolated converter, which is composed of elements such as a first switching tube, a second switching tube, an inductor, and a capacitor. The above elements are all two-terminal elements, including a first end and a second end; the first switching tube and the second switching tube operating complementarily form a half-bridge circuit. This half-bridge circuit includes a first end, a second end, and a midpoint. The first end is the input terminal of the reference level converter, and the second end is the output terminal of the reference level converter; the first end of the first switching tube is electrically connected to the first end of the half-bridge circuit, the second end of the first switching tube is electrically connected to the first end of the second switching tube and the midpoint of the half-bridge circuit, and the second end of the second switching tube is electrically connected to the second end of the half-bridge circuit; the first end of the inductor is electrically connected to the midpoint of the half-bridge circuit, and the second end is electrically connected to the ground port; the first end of the capacitor is electrically connected to the ground port, and the second end is electrically connected to the second end of the half-bridge circuit;

[0018] The input terminal of the reference level converter is electrically connected to the output port of a certain first type of basic conversion unit, and the output terminal is electrically connected to the second end of the second half-bridge circuit or the third half-bridge circuit of a certain stage conversion unit of the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit; let the voltage between the first end and the second end of the capacitor be V c , which is the voltage at the output terminal of the reference level converter, and the voltage between the first end of the half-bridge circuit and the ground port is V 1 , the duty cycle of the first switching tube is D, the duty cycle of the second switching tube is 1 - D, and the value of D ranges from 0 to 1. Then the relationship between V c and V 1 is as follows:

[0019]

[0020] By adjusting the value of D, the voltage at the output terminal of the reference level converter can be made adjustable, thereby adjusting the voltage transformation ratio of the N-stage converter.

[0021] Preferably, the reference level converter is an isolation converter, which is composed of a first, second, third, fourth, fifth, and sixth switching tube, a first inductor, a second inductor, a first capacitor, a second capacitor, and a transformer; the switching tubes, inductors, and capacitors are all two-terminal components, including a first terminal and a second terminal; the transformer has a primary first terminal, a primary second terminal, a secondary first terminal, a secondary second terminal, and a secondary midpoint. The number of turns of the inductor winding between the primary first terminal and the primary second terminal is p, the number of turns of the inductor winding between the secondary first terminal and the secondary midpoint is s, and the number of turns of the inductor winding between the secondary midpoint and the secondary second terminal is s. There is electrical isolation between the primary winding and the secondary winding;

[0022] The first terminal of the first switching tube is electrically connected to the first terminal of the second switching tube, the first terminal of the first capacitor, and the ground port. The secondary midpoint of the transformer is the output terminal of the reference level converter and is electrically connected to the second terminal of the first capacitor; the secondary first terminal of the transformer is electrically connected to the second terminal of the first switching tube, and the secondary second terminal is electrically connected to the second terminal of the second switching tube;

[0023] The third and fourth switching tubes operating in a complementary manner form a first half-bridge circuit, which includes a first terminal, a second terminal, and a midpoint. The first terminal of the third switching tube is electrically connected to the first terminal of the first half-bridge circuit. The second terminal of the third switching tube is electrically connected to the midpoint of the first half-bridge circuit and the first terminal of the fourth switching tube. The second terminal of the fourth switching tube is electrically connected to the second terminal of the first half-bridge circuit; the fifth and sixth switching tubes operating in a complementary manner form a second half-bridge circuit, which includes a first terminal, a second terminal, and a midpoint. The first terminal of the fifth switching tube is electrically connected to the first terminal of the second half-bridge circuit. The second terminal of the fifth switching tube is electrically connected to the midpoint of the second half-bridge circuit and the first terminal of the sixth switching tube. The second terminal of the sixth switching tube is electrically connected to the second terminal of the second half-bridge circuit;

[0024] The first terminal of the first inductor is electrically connected to the midpoint of the second half-bridge circuit. The second terminal of the first inductor is electrically connected to the first terminal of the second inductor and the primary first terminal of the transformer. The first terminal of the second capacitor is electrically connected to the midpoint of the first half-bridge circuit. The second terminal of the second capacitor is electrically connected to the second terminal of the second inductor and the primary second terminal of the transformer; the input terminal of the reference level converter is electrically connected to the first terminal of the first half-bridge circuit and the first terminal of the second half-bridge circuit. The second terminal of the first half-bridge circuit is electrically connected to the second terminal of the second half-bridge circuit and the ground port;

[0025] The input terminal of the reference level converter is electrically connected to the positive pole of the power supply. The output terminal is electrically connected to the second terminal of the second half-bridge circuit or the third half-bridge circuit of a certain stage conversion unit of the N-level converter, or the second terminals of the second half-bridge circuit and the third half-bridge circuit; Let the voltage between the first terminal and the second terminal of the first capacitor be V c, which is the output terminal voltage of the reference level converter; after determining the values of p and s of the transformer, the voltage transformation ratio of the transformer is a fixed value. By adjusting the duty cycle or switching frequency of the switching tube, the output terminal voltage of the reference level converter can be adjusted, thereby adjusting the voltage transformation ratio of the N-stage converter.

[0026] Preferably, the reference level converter is a non-isolated converter, which is composed of elements such as a first switching tube, a second switching tube, an inductor, and a capacitor. The above elements are all two-terminal elements, including a first end and a second end; the first switching tube and the second switching tube operating complementarily form a half-bridge circuit. The half-bridge circuit includes a first end, a second end, and a midpoint. The first end is the input end of the reference level converter and is electrically connected to the first end of the first switching tube; the second end of the first switching tube is electrically connected to the first end of the second switching tube and the midpoint of the half-bridge circuit. The second end of the second switching tube is electrically connected to the second end of the half-bridge circuit; the first end of the inductor is electrically connected to the midpoint of the half-bridge circuit, and the second end is the output end of the reference level converter and is electrically connected to the first end of the capacitor; the second end of the capacitor is electrically connected to the second end of the half-bridge circuit and the ground port;

[0027] The input end of the reference level converter is electrically connected to the positive pole of the power supply. The output end is electrically connected to the second end of the second half-bridge circuit or the third half-bridge circuit of a certain stage conversion unit of the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit; let the voltage between the first end and the second end of the capacitor be V c , which is the output terminal voltage of the reference level converter, and the voltage of the power supply is V in , the duty cycle of the first switching tube is D, and the duty cycle of the second switching tube is 1 - D. The value of D ranges from 0 to 1, then V c and V in The relationship between them is:

[0028] V c = DV in

[0029] By adjusting the value of D, the output terminal voltage of the reference level converter can be adjusted, thereby adjusting the voltage transformation ratio of the N-stage converter.

[0030] Preferably, the first half-bridge circuit is composed of a first switching tube and a second switching tube that operate complementarily. The first end of the first switching tube is electrically connected to the second end of the second switching tube and the midpoint of the first half-bridge circuit. The second end of the first switching tube is electrically connected to the second end of the first half-bridge circuit. The first end of the second switching tube is electrically connected to the first end of the first half-bridge circuit; the second half-bridge circuit is composed of a third switching tube and a fourth switching tube that operate complementarily. The first end of the third switching tube is electrically connected to the second end of the fourth switching tube and the midpoint of the second half-bridge circuit. The second end of the third switching tube is electrically connected to the second end of the second half-bridge circuit. The first end of the fourth switching tube is electrically connected to the first end of the second half-bridge circuit; the third half-bridge circuit is composed of a fifth switching tube and a sixth switching tube that operate complementarily. The first end of the fifth switching tube is electrically connected to the second end of the sixth switching tube and the midpoint of the third half-bridge circuit. The second end of the fifth switching tube is electrically connected to the second end of the third half-bridge circuit. The first end of the sixth switching tube is electrically connected to the first end of the third half-bridge circuit.

[0031] Preferably, the first resonant cavity is composed of an inductor and a capacitor, and the inductor and the capacitor are connected in series.

[0032] Preferably, the second resonant cavity is composed of an inductor and a capacitor, and the inductor and the capacitor are connected in series, or is composed of only a capacitor.

[0033] Preferably, all the first switching tubes, all the third switching tubes, and the sixth switching tubes of each stage of the conversion unit formed by the second type of basic conversion unit from the first-stage conversion unit to the Nth-stage conversion unit are turned on and off simultaneously. All the second switching tubes, all the fourth switching tubes, and the fifth switching tubes of each stage of the conversion unit formed by the second type of basic conversion unit from the first-stage conversion unit to the Nth-stage conversion unit are turned on and off simultaneously; without considering the dead time, the on-duty ratio and off-duty ratio of each switching tube are 50%; all the switching tubes of each stage of the conversion unit from the first-stage conversion unit to the Nth-stage conversion unit operate at a variable frequency or a fixed frequency.

[0034] Preferably, a high-frequency compensation circuit is further configured. The high-frequency compensation circuit includes an input terminal, an output terminal, and a ground terminal. The input terminal of the high-frequency compensation circuit is electrically connected to the input terminal of the N-stage converter, the positive pole of the power supply, or the output port of any first-type basic conversion unit in the N-stage converter. The output terminal is electrically connected to the positive pole of the load, and the ground terminal is electrically connected to the negative pole of the input power supply; the high-frequency compensation circuit only operates when the DC / DC converter is in an unstable transient state or during a state switching instant. When the voltage of the power supply fluctuates or the load power does not match the output power of the converter, resulting in fluctuations in the actual output voltage, the high-frequency compensation circuit compensates for high-frequency power fluctuations, improves the transient response of the DC / DC converter, and stops operating when the DC / DC converter is in a steady state and does not perform power conversion.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] Compared with the traditional two-stage series-connected converter, the present invention only has a main power converter for voltage conversion at one stage, reducing the number of power conversions, decreasing power loss, improving the efficiency of the converter, and at the same time reducing the volume of the converter and increasing the power density.

[0037] Compared with the existing switched resonant cavity converter, the present invention increases the ratio of the input voltage to the output voltage. With the same number of transformation units, it reduces the number of switching devices, inductors, and capacitors used, decreases power loss, improves the efficiency of the converter, and reduces costs.

[0038] By adjusting the voltage value at the output end of the reference level converter, the voltage conversion ratio of the N-stage converter is adjusted, achieving resistance to voltage fluctuations and wide-range changes of the power supply voltage, realizing wide-range gain adjustment of the converter, and ensuring a stable output voltage on the load side. The positive and negative as well as the high and low of this level value affect the voltage conversion ratio of the N-stage converter.

[0039] The power supply at the input end of the reference level converter can be selected as an external power supply or take power from the inside of the entire converter system. At the same time, the connection point between the input end and the output end of the reference level converter can be freely selected according to the stress of the devices in the actual application circuit.

[0040] A high-frequency compensation circuit can be added on the basis of the multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter proposed by the present invention to compensate for the high-frequency power fluctuations when the DC / DC converter is in an unstable transient state or during a state switching instant, thereby improving the dynamic response speed and reducing the voltage fluctuation on the load side. Brief Description of the Drawings

[0041] Figure 1 Schematic diagram of the first type of basic transformation unit structure for this embodiment.

[0042] Figure 2 Schematic diagram of the second type of basic transformation unit structure for this embodiment.

[0043] Figure 3 Schematic diagram of the resonant cavity structure for this embodiment.

[0044] Figure 4 Schematic diagram of the half-bridge circuit structure for this embodiment.

[0045] Figure 5 Schematic diagram of the circuit structure and connection method when the reference level converter for this embodiment is an external power supply (without high-frequency compensation).

[0046] Figure 6The reference level converter in this embodiment is a schematic diagram of the circuit structure and connection method of an external power supply with a high-frequency compensation circuit added.

[0047] Figure 7 The reference level converter in this embodiment is a non-isolated converter. When the input terminal is connected to the internal connection point of the N-stage converter, the output terminal is a negative voltage, and the number of transformation unit stages N is 4, it is a schematic diagram of a circuit structure and connection method (without high-frequency compensation).

[0048] Figure 8 The reference level converter in this embodiment is an isolated type. When the input terminal is connected to the power supply, the output terminal is a negative voltage, and the number of transformation unit stages N is 3, it is a schematic diagram of a circuit structure and connection method (without high-frequency compensation).

[0049] Figure 9 The reference level converter in this embodiment is a non-isolated converter. When the input terminal is connected to the power supply, the output terminal is a positive voltage, and the number of transformation unit stages N is 3, it is a schematic diagram of a circuit structure and connection method (without high-frequency compensation). Detailed implementation manners

[0050] The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the implementation manners of the present invention are not limited thereto.

[0051] This embodiment provides a multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter, which is composed of an N-stage high-ratio DC / DC converter and a reference level converter. The N-stage high-ratio DC / DC converter is an N-stage converter composed of N-stage transformation units. N is an integer greater than or equal to 2. It is a non-isolated converter, composed of elements such as switching tubes, capacitors, and inductors, and has an input terminal and an output terminal for realizing high-ratio voltage conversion. The reference level converter is an isolated converter or a non-isolated converter, composed of some of the elements such as switching tubes, inductors, capacitors, diodes, and transformers, and has an input terminal and an output terminal. The output terminal can output adjustable voltages of different polarities, or the reference level converter is an independent external power supply, and has an output terminal capable of outputting adjustable voltages of different polarities.

[0052] The first-stage transformation unit of the N-stage converter adopts the first type of basic transformation unit, and the other transformation units except the first stage adopt the first type of basic transformation unit or the second type of basic transformation unit.

[0053] Such as Figure 1As shown in the figure, the first type of basic conversion unit includes: an input port, an output port, a first resonant cavity, a second resonant cavity, a first half-bridge circuit, a second half-bridge circuit, and a ground port. The first end of the first half-bridge circuit is electrically connected to the input port, and the second end of the first half-bridge circuit is electrically connected to the output port; the first end of the first resonant cavity is electrically connected to the midpoint of the first half-bridge circuit, and the second end of the first resonant cavity is electrically connected to the midpoint of the second half-bridge circuit; the first end of the second resonant cavity is electrically connected to the output port, and the second end of the second resonant cavity is electrically connected to the ground port.

[0054] As Figure 2 shown in the figure, the second type of basic conversion unit includes: an input port, an output port, a first resonant cavity, a second resonant cavity, a first half-bridge circuit, a second half-bridge circuit, and a third half-bridge circuit. The first end of the first half-bridge circuit is electrically connected to the input port, and the second end of the first half-bridge circuit is electrically connected to the output port; the first end of the first resonant cavity is electrically connected to the midpoint of the first half-bridge circuit, and the second end of the first resonant cavity is electrically connected to the midpoint of the second half-bridge circuit; the first end of the second resonant cavity is electrically connected to the output port, and the second end of the second resonant cavity is electrically connected to the midpoint of the third half-bridge circuit.

[0055] As Figure 3 shown in the figure, the resonant cavity includes a first end and a second end, and is composed of an inductor and a capacitor, and the inductor and the capacitor are connected in series; or is composed of only a capacitor.

[0056] As Figure 4 shown in the figure, the half-bridge circuit includes a first end, a second end, and a midpoint, and is composed of a first switching tube and a second switching tube that operate complementarily, and the switching tube operates at a variable frequency or a fixed frequency.

[0057] The first half-bridge circuit of the N-stage converter is composed of a first switching tube Q1 and a second switching tube Q2 that operate complementarily. The first end of the first switching tube Q1 is electrically connected to the second end of the second switching tube Q2 and the midpoint of the first half-bridge circuit. The second end of the first switching tube Q1 is electrically connected to the second end of the first half-bridge circuit, and the first end of the second switching tube Q2 is electrically connected to the first end of the first half-bridge circuit; the second half-bridge circuit is composed of a third switching tube Q3 and a fourth switching tube Q4 that operate complementarily. The first end of the third switching tube Q3 is electrically connected to the second end of the fourth switching tube Q4 and the midpoint of the second half-bridge circuit. The second end of the third switching tube Q3 is electrically connected to the second end of the second half-bridge circuit, and the first end of the fourth switching tube Q4 is electrically connected to the first end of the second half-bridge circuit; the third half-bridge circuit is composed of a fifth switching tube Q5 and a sixth switching tube Q6 that operate complementarily. The first end of the fifth switching tube Q5 is electrically connected to the second end of the sixth switching tube Q6 and the midpoint of the third half-bridge circuit. The second end of the fifth switching tube Q5 is electrically connected to the second end of the third half-bridge circuit, and the first end of the sixth switching tube Q6 is electrically connected to the first end of the third half-bridge circuit.

[0058] All the first switching transistors Q1 of the first-stage to Nth-stage conversion units of the N-stage converter, all the third switching transistors Q3, and the sixth switching transistor Q6 of each stage of the conversion unit formed by the second-type basic conversion units are turned on and off simultaneously. All the second switching transistors Q2 of the first-stage to Nth-stage conversion units of the N-stage converter, all the fourth switching transistors Q4, and the fifth switching transistor Q5 of each stage of the conversion unit formed by the second-type basic conversion units are turned on and off simultaneously. Without considering the dead time, the duty cycle of the on and off of each switching transistor is 50%. All the switching transistors of each stage of the conversion unit from the first-stage to Nth-stage conversion units operate at variable frequency or fixed frequency.

[0059] The output port of the first-stage conversion unit in the N-stage converter is the output terminal of the N-stage high-ratio DC / DC converter, which is electrically connected to the positive pole of the load. The output ports of the other conversion units except the first-stage conversion unit are electrically connected to the input ports of the lower-stage conversion units. The input port of the Nth-stage conversion unit is the input terminal of the N-stage high-ratio DC / DC converter, which is electrically connected to the positive pole of the power supply; the grounding port of the N-stage high-ratio DC / DC converter is at the same potential as the negative pole of the load and the negative pole of the power supply.

[0060] Except for the case where the reference level converter is an independent external power supply, the input terminal of the reference level converter is electrically connected to the input terminal of the N-stage converter, the positive pole of the power supply, or the output port of any first-type basic conversion unit in the N-stage converter; the output terminal can output adjustable voltages of different polarities, and the level value of the adjustable voltage is positive, negative, or zero potential; the second end of the second half-bridge circuit or the third half-bridge circuit of at least one stage of the conversion unit in the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit are electrically connected to the output terminal of a reference level converter; the on and off time lengths of the switching transistors inside the reference level converter affect the voltage at the output terminal of the converter. Therefore, controlling the duty cycle of the switching transistors can adjust the level value at the output terminal of the reference level converter.

[0061] The positive and negative and high and low of the level value at the output terminal of the reference level converter affect the voltage ratio of the N-stage converter: when the output terminal voltage of the reference level converter is positive, the voltage ratio of the N-stage converter will become smaller; when the output terminal voltage is negative, the voltage ratio of the N-stage converter will become larger; the higher the output terminal voltage of the reference level converter, the smaller the voltage ratio of the N-stage converter, and the lower the output terminal voltage, the larger the voltage ratio of the N-stage converter.

[0062] As Figure 5As shown, the reference level converter is an independent external power supply, and the voltage value at the output terminal of this external power supply can be positive, negative, or zero potential; the second resonant cavity of the first conversion unit of the N-level converter consists only of a capacitor. The first end of the second half-bridge circuit of the N-level converter is electrically connected to the output port, and the second end is electrically connected to the output terminal of the reference level converter; the first end of the third half-bridge circuit in the second type of basic conversion unit is electrically connected to the output port of the lower-level conversion unit, and the second end is electrically connected to the output terminal of the reference level converter.

[0063] As Figure 6 shown, this example is Figure 5 a schematic diagram of adding a high-frequency compensation circuit on the basis of [description of the basis]. The input terminal of the high-frequency compensation circuit is electrically connected to the positive pole of the power supply, the output terminal is electrically connected to the positive pole of the load, and the grounding terminal is electrically connected to the negative pole of the input power supply.

[0064] As Figure 7 shown, the reference level converter is a non-isolated converter, which consists of a first switching tube S1, a second switching tube S2, an inductor L, and a capacitor C. The above components are all two-terminal components, including a first end and a second end; the first switching tube S1 and the second switching tube S2 operating complementarily form a half-bridge circuit. This half-bridge circuit includes a first end, a second end, and a midpoint. The first end is the input terminal of the reference level converter, and the second end is the output terminal of the reference level converter; the first end of the first switching tube S1 is electrically connected to the first end of the half-bridge circuit, the second end of the first switching tube S1 is electrically connected to the first end of the second switching tube S2 and the midpoint of the half-bridge circuit, and the second end of the second switching tube S2 is electrically connected to the second end of the half-bridge circuit; the first end of the inductor L is electrically connected to the midpoint of the half-bridge circuit, and the second end is electrically connected to the grounding port; the first end of the capacitor C is electrically connected to the grounding port, and the second end is electrically connected to the second end of the half-bridge circuit;

[0065] Among them, the third conversion unit of the N-level converter adopts the first type of basic conversion unit, and the second resonant cavity consists only of a capacitor. The second and fourth conversion units adopt the second type of basic conversion unit, and the second resonant cavity consists of an inductor and a capacitor; the input terminal of the reference level converter is electrically connected to the output port of the third conversion unit, and the output terminal is electrically connected to the second end of the second half-bridge circuit of the fourth conversion unit; the first end of the second half-bridge circuit of the N-level converter is electrically connected to the output port, and the second end of the second half-bridge circuit except the fourth conversion unit is electrically connected to the grounding port; the first end of the third half-bridge circuit is electrically connected to the output port of the lower-level conversion unit, and the second end is electrically connected to the grounding port; let the voltage between the first end and the second end of the capacitor be V c , which is the output terminal voltage of the reference level converter, and the voltage between the first end of the half-bridge circuit and the grounding port is V 1 , the duty cycle of the first switching tube is D, the duty cycle of the second switching tube is 1 - D, and the value range of D is 0 - 1. Then V c and V1 The relational expression between them is:

[0066]

[0067] By adjusting the value of D, the voltage at the output end of the reference level converter can be made adjustable, thereby adjusting the voltage transformation ratio of the N-stage converter.

[0068] As Figure 8 shown, the reference level converter is an isolation converter, which is composed of the first, second, third, fourth, fifth, and sixth switching tubes, the first inductor, the second inductor, the first capacitor, the second capacitor, and the transformer; the switching tubes, inductors, and capacitors are all two-terminal components, including a first end and a second end; the transformer has a primary first end, a primary second end, a secondary first end, a secondary second end, and a secondary midpoint. The number of turns of the inductor winding between the primary first end and the primary second end is p, the number of turns of the inductor winding between the secondary first end and the secondary midpoint is s, and the number of turns of the inductor winding between the secondary midpoint and the secondary second end is s. There is electrical isolation between the primary winding and the secondary winding; the first end of the first switching tube is electrically connected to the first end of the second switching tube, the first end of the first capacitor, and the ground port. The secondary midpoint of the transformer is the output end of the reference level converter and is electrically connected to the second end of the first capacitor; the secondary first end of the transformer is electrically connected to the second end of the first switching tube, and the secondary second end of the transformer is electrically connected to the second end of the second switching tube;

[0069] The third switching tube and the fourth switching tube operating complementarily form a first half-bridge circuit, which includes a first end, a second end, and a midpoint. The first end of the third switching tube is electrically connected to the first end of the first half-bridge circuit. The second end of the third switching tube is electrically connected to the midpoint of the first half-bridge circuit and the first end of the fourth switching tube. The second end of the fourth switching tube is electrically connected to the second end of the first half-bridge circuit; the fifth switching tube and the sixth switching tube operating complementarily form a second half-bridge circuit, which includes a first end, a second end, and a midpoint. The first end of the fifth switching tube is electrically connected to the first end of the second half-bridge circuit. The second end of the fifth switching tube is electrically connected to the midpoint of the second half-bridge circuit and the first end of the sixth switching tube. The second end of the sixth switching tube is electrically connected to the second end of the second half-bridge circuit;

[0070] The first end of the first inductor is electrically connected to the midpoint of the second half-bridge circuit. The second end of the first inductor is electrically connected to the first end of the second inductor and the primary first end of the transformer. The first end of the second capacitor is electrically connected to the midpoint of the first half-bridge circuit. The second end of the second capacitor is electrically connected to the second end of the second inductor and the primary second end of the transformer; the input end of the reference level converter is electrically connected to the first end of the first half-bridge circuit and the first end of the second half-bridge circuit. The second end of the first half-bridge circuit is electrically connected to the second end of the second half-bridge circuit and the ground port;

[0071] Among them, the second and third transformation units of the N-level converter adopt the second type of basic transformation unit; the input end of the reference level converter is electrically connected to the positive pole of the power supply, and the output end is electrically connected to the second end of the second half-bridge circuit and the second end of the third half-bridge circuit of the third transformation unit; the first end of the second half-bridge circuit of the N-level converter is electrically connected to the output port, and the second end of the second half-bridge circuit except the third transformation unit is electrically connected to the ground port; the first end of the third half-bridge circuit is electrically connected to the output port of the lower-level transformation unit, and the second end of the third half-bridge circuit except the third transformation unit is electrically connected to the ground port; let the voltage between the first end and the second end of the first capacitor be V c , which is the output terminal voltage of the reference level converter; after determining the values of p and s of the transformer, the voltage transformation ratio of the transformer is a fixed value. By adjusting the duty cycle or switching frequency of the switching tube, the output terminal voltage of the reference level converter can be adjusted, so as to adjust the voltage transformation ratio of the N-level converter.

[0072] As Figure 9 shown, the reference level converter is a non-isolated converter, which is composed of a first switching tube S1, a second switching tube S2, an inductor L, and a capacitor C. The above components are all two-terminal components, including a first end and a second end; the first switching tube S1 and the second switching tube S2 operating complementarily form a half-bridge circuit. This half-bridge circuit includes a first end, a second end, and a midpoint. The first end is the input end of the reference level converter and is electrically connected to the first end of the first switching tube S1; the second end of the first switching tube S1 is electrically connected to the first end of the second switching tube S2 and the midpoint of the half-bridge circuit, and the second end of the second switching tube S2 is electrically connected to the second end of the half-bridge circuit; the first end of the inductor L is electrically connected to the midpoint of the half-bridge circuit, and the second end is the output end of the reference level converter and is electrically connected to the first end of the capacitor C; the second end of the capacitor C is electrically connected to the second end of the half-bridge circuit and the ground port;

[0073] Among them, the second and third transformation units of the N-level converter adopt the second type of basic transformation unit; the input end of the reference level converter is electrically connected to the positive pole of the power supply, and the output end is electrically connected to the second end of the second half-bridge circuit of the first transformation unit; the first end of the second half-bridge circuit of the N-level converter is electrically connected to the output port, and the second end of the second half-bridge circuit except the first transformation unit is electrically connected to the ground port; the first end of the third half-bridge circuit is electrically connected to the output port of the lower-level transformation unit, and the second end is electrically connected to the ground port; let the voltage between the first end and the second end of the capacitor be V c , which is the output terminal voltage of the reference level converter, and the voltage of the power supply is V in , the duty cycle of the first switching tube is D, the duty cycle of the second switching tube is 1-D, and the value of D is 0-1. Then the relationship between V c and V in is:

[0074] Vc = DV in

[0075] By adjusting the value of D, the voltage at the output terminal of the reference level converter can be made adjustable, thereby adjusting the voltage transformation ratio of the N-stage converter.

[0076] The above-described embodiments are only the preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and connection principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. Multi-reference level wide-range gain-adjustable high-ratio DC / DC converter, Characterized in that: This converter is composed of an N-stage high-ratio DC / DC converter and a reference level converter. The N-stage high-ratio DC / DC converter is an N-stage converter composed of N conversion units. N is an integer greater than or equal to 2 and is a non-isolated converter for realizing high-ratio voltage conversion; the reference level converter is an isolated converter or a non-isolated converter, or the reference level converter is an independent external power supply; The first conversion unit of the N-stage converter adopts the first type of basic conversion unit, and the other conversion units except the first stage adopt the first type of basic conversion unit or the second type of basic conversion unit. The parts included in both the first type of basic conversion unit and the second type of basic conversion unit are: Input port; Output port; The first resonant cavity, including a first end and a second end; The second resonant cavity, including a first end and a second end. The first end of this second resonant cavity is electrically connected to the output port; The first half-bridge circuit, including a first end, a second end and a midpoint. The midpoint of this first half-bridge circuit is electrically connected to the first end of the first resonant cavity. The first end of this first half-bridge circuit is electrically connected to the input port, and the second end is electrically connected to the output port; The second half-bridge circuit, including a first end, a second end and a midpoint. The midpoint of this second half-bridge circuit is electrically connected to the second end of the first resonant cavity. The first end of this second half-bridge circuit is electrically connected to the output port, and the second end is electrically connected to the ground port or the output end of the reference level converter; The second end of the second resonant cavity of the first type of basic conversion unit is electrically connected to the ground port. The second type of basic conversion unit further includes: The third half-bridge circuit, including a first end, a second end and a midpoint. The midpoint of this third half-bridge circuit is electrically connected to the second end of the second resonant cavity of the second type of basic conversion unit. The first end of this third half-bridge circuit is electrically connected to the output port of the lower-level conversion unit, and the second end is electrically connected to the ground port or the output end of the reference level converter; The output port of the first conversion unit in the N-stage converter is the output end of the N-stage high-ratio DC / DC converter and is electrically connected to the positive pole of the load. The output ports of the other conversion units except the first conversion unit are electrically connected to the input port of the lower-level conversion unit. The input port of the Nth conversion unit is the input end of the N-stage high-ratio DC / DC converter and is electrically connected to the positive pole of the power supply; the ground port of the N-stage high-ratio DC / DC converter, the negative pole of the load and the negative pole of the power supply are at the same potential; Except for the case where the reference level converter is an independent external power supply, the input end of the reference level converter is electrically connected to the input end of the N-stage converter, the positive pole of the power supply, or the output port of any first-type basic conversion unit in the N-stage converter; the output end can output an adjustable voltage, and the level value of the adjustable voltage is positive, negative, or zero potential; the second end of the second half-bridge circuit or the third half-bridge circuit of at least one conversion unit in the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit are electrically connected to the output end of a reference level converter; the on and off times of the switching tubes inside the reference level converter affect the voltage at the output end of the converter, so controlling the duty cycle of the switching tubes can adjust the level value at the output end of the reference level converter; The positive and negative and high and low of the level value at the output end of the reference level converter affect the voltage conversion ratio of the N-stage converter: when the voltage at the output end of the reference level converter is positive, the voltage conversion ratio of the N-stage converter will become smaller, and when the output end voltage is negative, the voltage conversion ratio of the N-stage converter will become larger; the higher the voltage at the output end of the reference level converter, the smaller the voltage conversion ratio of the N-stage converter, and the lower the output end voltage, the larger the voltage conversion ratio of the N-stage converter; by adjusting the voltage conversion ratio of the N-stage converter, the fluctuations and wide-range changes of the power supply voltage can be resisted, the wide-range gain adjustment of the converter can be realized, and the stability of the load output voltage can be ensured.

2. The multi-reference level wide-range gain adjustment high-ratio DC / DC converter according to claim 1, characterized in that: The reference level converter is a non-isolated converter, which is composed of elements such as a first switching tube, a second switching tube, an inductor, and a capacitor. The above elements are all two-terminal elements, including a first end and a second end; the first switching tube and the second switching tube operating complementarily form a half-bridge circuit, which includes a first end, a second end, and a midpoint. The first end is the input end of the reference level converter, and the second end is the output end of the reference level converter; the first end of the first switching tube is electrically connected to the first end of the half-bridge circuit, the second end of the first switching tube is electrically connected to the first end of the second switching tube and the midpoint of the half-bridge circuit, and the second end of the second switching tube is electrically connected to the second end of the half-bridge circuit; the first end of the inductor is electrically connected to the midpoint of the half-bridge circuit, and the second end is electrically connected to the ground port; the first end of the capacitor is electrically connected to the ground port, and the second end is electrically connected to the second end of the half-bridge circuit; The input end of the reference level converter is electrically connected to the output port of a certain first - type basic conversion unit, and the output end is electrically connected to the second end of the second half - bridge circuit or the third half - bridge circuit of a certain stage conversion unit in the N - stage converter, or the second ends of the second half - bridge circuit and the third half - bridge circuit; assume the voltage between the first end and the second end of the capacitor is V c , which is the output - end voltage of the reference level converter, and the voltage between the first end of the half - bridge circuit and the grounding port is V 1 . The duty cycle of the first switching tube is D, and the duty cycle of the second switching tube is 1 - D. The value range of D is 0 - 1. Then the relationship between V c and V 1 is as follows: By adjusting the value of D, the voltage at the output end of the reference level converter can be made adjustable, so as to adjust the voltage conversion ratio of the N-stage converter.

3. The multi-reference level wide-range gain adjustment high-ratio DC / DC converter according to claim 1, characterized in that: The reference level converter is an isolation converter, which is composed of the first, second, third, fourth, fifth, and sixth switching tubes, the first inductor, the second inductor, the first capacitor, the second capacitor, and a transformer; the switching tubes, inductors, and capacitors are all two-terminal components, including a first terminal and a second terminal; the transformer has a primary first terminal, a primary second terminal, a secondary first terminal, a secondary second terminal, and a secondary midpoint. The number of turns of the inductor winding between the primary first terminal and the primary second terminal is p, the number of turns of the inductor winding between the secondary first terminal and the secondary midpoint is s, and the number of turns of the inductor winding between the secondary midpoint and the secondary second terminal is s. There is electrical isolation between the primary winding and the secondary winding. The first terminal of the first switching tube is electrically connected to the first terminal of the second switching tube, the first terminal of the first capacitor, and the ground port. The secondary midpoint of the transformer is the output terminal of the reference level converter and is electrically connected to the second terminal of the first capacitor; the secondary first terminal of the transformer is electrically connected to the second terminal of the first switching tube, and the secondary second terminal of the transformer is electrically connected to the second terminal of the second switching tube. The third switching tube and the fourth switching tube operating complementarily form a first half-bridge circuit. The first half-bridge circuit includes a first terminal, a second terminal, and a midpoint. The first terminal of the third switching tube is electrically connected to the first terminal of the first half-bridge circuit. The second terminal of the third switching tube is electrically connected to the midpoint of the first half-bridge circuit and the first terminal of the fourth switching tube. The second terminal of the fourth switching tube is electrically connected to the second terminal of the first half-bridge circuit; the fifth switching tube and the sixth switching tube operating complementarily form a second half-bridge circuit. The second half-bridge circuit includes a first terminal, a second terminal, and a midpoint. The first terminal of the fifth switching tube is electrically connected to the first terminal of the second half-bridge circuit. The second terminal of the fifth switching tube is electrically connected to the midpoint of the second half-bridge circuit and the first terminal of the sixth switching tube. The second terminal of the sixth switching tube is electrically connected to the second terminal of the second half-bridge circuit. The first terminal of the first inductor is electrically connected to the midpoint of the second half-bridge circuit. The second terminal of the first inductor is electrically connected to the first terminal of the second inductor and the primary first terminal of the transformer. The first terminal of the second capacitor is electrically connected to the midpoint of the first half-bridge circuit. The second terminal of the second capacitor is electrically connected to the second terminal of the second inductor and the primary second terminal of the transformer; the input terminal of the reference level converter is electrically connected to the first terminal of the first half-bridge circuit and the first terminal of the second half-bridge circuit. The second terminal of the first half-bridge circuit is electrically connected to the second terminal of the second half-bridge circuit and the ground port. The input end of the reference level converter is electrically connected to the positive pole of the power supply, and the output end is electrically connected to the second end of the second half-bridge circuit or the third half-bridge circuit of a certain transformation unit of the N-level converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit; let the voltage between the first end and the second end of the first capacitor be V c , which is the output voltage of the reference level converter; after determining the values of p and s of the transformer, the voltage transformation ratio of the transformer is a fixed value. By adjusting the duty cycle or switching frequency of the switching tube, the output voltage of the reference level converter can be adjusted, so as to adjust the voltage transformation ratio of the N-level converter.

4. The multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter according to claim 1, characterized in that: The reference level converter is a non-isolated converter, which is composed of components such as a first switching tube, a second switching tube, an inductor and a capacitor. These components are all two-terminal components, including a first terminal and a second terminal; the first switching tube and the second switching tube operating complementarily form a half-bridge circuit. This half-bridge circuit includes a first terminal, a second terminal and a midpoint. The first terminal is the input terminal of the reference level converter and is electrically connected to the first terminal of the first switching tube; the second terminal of the first switching tube is electrically connected to the first terminal of the second switching tube and the midpoint of the half-bridge circuit. The second terminal of the second switching tube is electrically connected to the second terminal of the half-bridge circuit; the first terminal of the inductor is electrically connected to the midpoint of the half-bridge circuit, and the second terminal is the output terminal of the reference level converter and is electrically connected to the first terminal of the capacitor; the second terminal of the capacitor is electrically connected to the second terminal of the half-bridge circuit and the ground port; The input end of the reference level converter is electrically connected to the positive pole of the power supply, and the output end is electrically connected to the second end of the second half-bridge circuit or the third half-bridge circuit of a certain stage conversion unit of the N-stage converter, or the second ends of the second half-bridge circuit and the third half-bridge circuit; let the voltage between the first end and the second end of the capacitor be V c , which is the output voltage of the reference level converter, and the voltage of the power supply is V in , the duty cycle of the first switching tube is D, the duty cycle of the second switching tube is 1 - D, and the value range of D is 0 - 1, then V c and V in The relationship between them is: V c = DV in By adjusting the value of D, the voltage at the output terminal of the reference level converter can be made adjustable, thereby adjusting the voltage transformation ratio of the N-stage converter.

5. The multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter according to claim 1, characterized in that: The first half-bridge circuit is composed of a first switching tube and a second switching tube operating complementarily. The first terminal of the first switching tube is electrically connected to the second terminal of the second switching tube and the midpoint of the first half-bridge circuit. The second terminal of the first switching tube is electrically connected to the second terminal of the first half-bridge circuit. The first terminal of the second switching tube is electrically connected to the first terminal of the first half-bridge circuit; the second half-bridge circuit is composed of a third switching tube and a fourth switching tube operating complementarily. The first terminal of the third switching tube is electrically connected to the second terminal of the fourth switching tube and the midpoint of the second half-bridge circuit. The second terminal of the third switching tube is electrically connected to the second terminal of the second half-bridge circuit. The first terminal of the fourth switching tube is electrically connected to the first terminal of the second half-bridge circuit; the third half-bridge circuit is composed of a fifth switching tube and a sixth switching tube operating complementarily. The first terminal of the fifth switching tube is electrically connected to the second terminal of the sixth switching tube and the midpoint of the third half-bridge circuit. The second terminal of the fifth switching tube is electrically connected to the second terminal of the third half-bridge circuit. The first terminal of the sixth switching tube is electrically connected to the first terminal of the third half-bridge circuit.

6. The multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter according to claim 5, characterized in that: The first resonant cavity is composed of an inductor and a capacitor, and the inductor and the capacitor are connected in series.

7. The multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter according to claim 5, characterized in that: The second resonant cavity is composed of an inductor and a capacitor, and the inductor and the capacitor are connected in series, or is composed of only a capacitor.

8. The multi-reference-level wide-range gain-adjustable high-ratio DC / DC converter according to claim 5, characterized in that: All the first switching transistors, all the third switching transistors of the first-level to N-level conversion units, and the sixth switching transistors of each level of conversion units formed by the second type of basic conversion units are turned on and off simultaneously. All the second switching transistors, all the fourth switching transistors of the first-level to N-level conversion units, and the fifth switching transistors of each level of conversion units formed by the second type of basic conversion units are turned on and off simultaneously. Without considering the dead time, the duty cycle of the on and off of each switching transistor is 50%. All the switching transistors of each level of conversion units from the first-level to the N-level conversion units operate at variable frequency or fixed frequency.

9. The multi-reference level wide-range gain-adjustable high-ratio DC / DC converter according to claim 1, characterized in that: it is further configured with a high-frequency compensation circuit. The high-frequency compensation circuit includes an input terminal, an output terminal and a ground terminal. The input terminal of the high-frequency compensation circuit is electrically connected to the input terminal of the N-level converter, the positive pole of the power supply or the output port of any first type of basic conversion unit in the N-level converter. The output terminal is electrically connected to the positive pole of the load, and the ground terminal is electrically connected to the negative pole of the input power supply. The high-frequency compensation circuit only operates when the DC / DC converter is in an unstable transient state or during a state switching instant. When the voltage of the power supply fluctuates or the load power does not match the output power of the converter, resulting in fluctuations in the actual output voltage, the high-frequency compensation circuit compensates for high-frequency power fluctuations to improve the transient response of the DC / DC converter and stops operating when the DC / DC converter is in a steady state without performing power conversion.

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