Module valley filling circuit and switching power supply

Abstract

The invention discloses a module valley filling circuit and a switching power supply. The circuit comprises M primary power modules and N valley filling circuits, the primary side power modules are connected through the valley-fill circuit, the valley-fill circuit comprises a diode, an upper valley-fill tube and a lower valley-fill tube, the first end of the upper valley-fill tube is connected to the positive input end of any one of the primary side power modules from the first primary side power module to the ith primary side power module, and the second end of the lower valley-fill tube is connected to the negative input end of any one of the primary side power modules from the first primary side power module to the ith primary side power module. The first end of the lower valley fill tube is connected to the negative input end of any one of the first primary power module to the ith primary power module, and the negative input end of the ith primary power module is connected to the anode of the diode. And the positive input end of the (i + 1) th primary side power module is respectively connected to the cathode of the diode and the second end of the upper valley-fill tube. The series-parallel connection of a plurality of small primary side power modules can be realized, the input voltage range and the output power of the power supply can be greatly expanded, and the application of the product is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and particularly to a module valley filling circuit and a switching power supply. Background Art

[0002] In the industrial and civil fields, it is usually necessary to rectify grid alternating current into direct current, and based on different application scenarios, the required input voltage ranges are different. For example, in the coal mine industry, there are various equipment with different power supply voltages. The power supply voltages for lighting, signals, telephones, and handheld electrical equipment are 127VAC, the lighting voltage in the fresh air roadway on the ground and underground is 220VAC, the distribution voltage of the low-voltage power grid on the ground and in small underground mines is 380VAC, the rated voltage of the underground low-voltage power grid is 660VAC, and there is even a higher power supply voltage of 1140VAC. In addition, the development of DC application scenarios such as energy storage and photovoltaic industries (both require a wide input voltage range) has led to the development of switching power supplies towards a wider input voltage range.

[0003] Considering factors such as volume and power density, a wide-range switching power supply can use the function of the valley filling circuit to make the power supply volume smaller while ensuring that the capacitance and efficiency are maintained at a high level when the input is low voltage; when the input is high voltage, the stress of each component is at a low level, enhancing the application reliability of the product.

[0004] For the above reasons, the development of a wide-range switching power supply is particularly important, and the valley filling technology can bring more advantages to the wide-range input power supply in terms of volume, performance, etc. Therefore, it is necessary to conduct innovative exploration on the module valley filling circuit. Summary of the Invention

[0005] In view of this, the main technical problem to be solved by the present invention is to provide a module valley filling circuit and a switching power supply that greatly broaden the input voltage range of the power supply.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a module valley filling circuit, including M primary power modules and N valley filling circuits, where M is a natural number greater than or equal to 2, and N is a natural number greater than or equal to 1 and less than M;

[0008] Each of the primary power modules is connected through the valley-fill circuit. The valley-fill circuit includes a diode, an upper valley-fill transistor, and a lower valley-fill transistor. The first end of the upper valley-fill transistor is connected to the positive input terminal of any one of the first to the i-th primary power modules. The first end of the lower valley-fill transistor is connected to the negative input terminal of any one of the first to the i-th primary power modules. The negative input terminal of the i-th primary power module is connected to the anode of the diode. The positive input terminal of the (i + 1)-th primary power module is respectively connected to the cathode of the diode and the second end of the upper valley-fill transistor. The negative input terminal of the (i + 1)-th primary power module is connected to the second end of the lower valley-fill transistor; where 1 ≤ i ≤ M - 1 and i is a positive integer.

[0009] Optionally, the drain of the switching transistor in the primary power module is connected to the positive electrode of the capacitor as the positive input terminal of the primary power module;

[0010] Or, the primary winding is connected to the positive electrode of the capacitor as the positive input terminal of the primary power module;

[0011] Or, the source of the switching transistor is connected to the negative terminal of the capacitor as the negative input terminal of the primary power module;

[0012] Or, the primary winding is connected to the negative electrode of the capacitor as the negative input terminal of the primary power module.

[0013] Optionally, each of the primary power modules includes a capacitor C1, a switching transistor Q1, and a primary winding L1. The first end of the capacitor C1 and the first end of the switching transistor Q1 are connected together as the positive input terminal of the primary power module. The second end of the switching transistor Q1 is connected to the same-name end of the primary winding L1. The second end of the capacitor C1 and the different-name end of the primary winding L1 are connected as the negative input terminal of the primary power module.

[0014] Optionally, the primary power module includes a primary winding P11, a capacitor C1, a switching transistor Q1, a diode D1, and a primary winding P12. The first end of the capacitor C1 is respectively connected to the same-name end of the primary winding P11 and the different-name end of the primary winding P12. The different-name end of the primary winding P11 is connected to the first end of the switching transistor Q1. The same-name end of the primary winding P12 is connected to the cathode of the diode D1. The second end of the capacitor C1 is respectively connected to the second end of the switching transistor Q1 and the anode of the diode D1. The first end of the capacitor C1 is used as the positive input terminal of the primary power module, and the second end of the capacitor C1 is used as the negative input terminal of the primary power module.

[0015] Optionally, the primary power module includes a primary winding P11, a capacitor C1, a switching transistor Q1, a switching transistor Q2, a diode D1, and a diode D2. The first terminal of the capacitor C1 is respectively connected to the cathode of the diode D1 and the first terminal of the switching transistor Q1. The anode of the diode D1 is respectively connected to the terminal of the primary winding P11 with opposite name and the first terminal of the switching transistor Q2. The second terminal of the switching transistor Q1 is respectively connected to the terminal of the primary winding P11 with the same name and the cathode of the diode D2. The anode of the diode and the second terminal of the switching transistor Q2 are both connected to the capacitor C1. The first terminal of the capacitor C1 serves as the positive input terminal of the primary power module, and the second terminal of the capacitor C1 serves as the negative input terminal of the primary power module.

[0016] Optionally, the primary power module includes a primary winding P11, a capacitor C1, a capacitor Cr1, an inductor Lr1, a switching transistor Q1, and a switching transistor Q2. The first terminal of the capacitor C1 is connected to the first terminal of the switching transistor Q1. The second terminal of the switching transistor Q1 is connected to the first terminal of the switching transistor Q2. The second terminal of the switching transistor Q1 is connected to the terminal of the primary winding P11 with the same name through the inductor Lr1. The terminal of the primary winding P11 with opposite name is connected to the first terminal of the capacitor Cr1. The second terminal of the switching transistor Q2 and the second terminal of the capacitor Cr1 are both connected to the second terminal of the capacitor C1. The first terminal of the capacitor C1 serves as the positive input terminal of the primary power module, and the second terminal of the capacitor C1 serves as the negative input terminal of the primary power module.

[0017] Optionally, the primary power module includes a primary winding P11, a capacitor C1, a resistor R1, a resistor R2, a resistor R3, a voltage regulator diode Z1, a switching transistor Q1, and a switching transistor Q2. The first terminal of the capacitor C1 is respectively connected to the first terminal of the resistor R1 and the terminal of the primary winding P11 with the same name. The second terminal of the resistor R1 is connected to the cathode of the voltage regulator diode Z1. The second terminal of the resistor R1 is connected to the control terminal of the switching transistor Q1 through the resistor R2. The terminal of the primary winding P11 with opposite name is connected to the first terminal of the switching transistor Q1. The second terminal of the switching transistor Q1 is connected to the first terminal of the switching transistor Q2. The control terminal of the switching transistor Q2 is connected to the resistor R3. The anode of the voltage regulator Z1 and the second terminal of the switching transistor Q2 are both connected to the second terminal of the capacitor C1. The first terminal of the capacitor C1 serves as the positive input terminal of the primary power module, and the second terminal of the capacitor C1 serves as the negative input terminal of the primary power module.

[0018] Optionally, the primary power module includes a primary winding P11, a capacitor C1, a capacitor C2, a capacitor Cr1, an inductor Lr1, a switch Q1, a switch Q2, a switch Q3, and a switch Q4. A first end of the capacitor C1 is connected to a first end of the switch Q1. A second end of the switch Q1 is connected to a first end of the switch Q2. The second end of the switch Q1 is sequentially connected to the same-name end of the primary winding P11 through the capacitor Cr1 and the inductor Lr1. A second end of the capacitor C1 is respectively connected to a second end of the switch Q2, a first end of the switch Q3, and a first end of the capacitor C2. The different-name end of the primary winding P11 is respectively connected to a second end of the switch Q3 and a first end of the switch Q4. A second end of the switch Q4 is connected to a second end of the capacitor C2. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C2 serves as the negative input terminal of the primary power module.

[0019] Optionally, the upper valley-fill tube and the lower valley-fill tube are turned on or off simultaneously.

[0020] Optionally, the turns ratio of the primary winding in the primary power module is the same as that of the secondary winding of the corresponding transformer.

[0021] In a second aspect, the present invention further provides a switching power supply, and the switching power supply includes the module valley-fill circuit described in the first aspect.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. In the present invention, a diode is connected in series in the valley-fill circuit between each primary power module. The switch tube in the valley-fill circuit can play a role in making each primary power module flexibly connected in series or parallel. When it is necessary to switch from a low voltage to a high voltage AC voltage input application, the parallel state of each primary power module is disconnected, so that each primary power module is connected in series to share the voltage, reducing the voltage sharing effect of a single primary power module and reducing the withstand voltage of the switch tube in each primary power module, greatly increasing the upper limit of the input voltage range of the input switching power supply; when switching from a high voltage to a low voltage input alternating current application, by closing the switch tubes that connect each module in series or parallel, each primary power module is excited in parallel, reducing the power loop current and the capacitance value of the energy storage capacitor in each primary power module under low input voltage applications, enabling a single switching power supply to achieve a lower input voltage and a larger power.

[0024] 2. In the present invention, the switching timings of all switch tubes connecting two primary power modules are consistent, and they need to be turned on and off simultaneously. By using a single-chip control signal, multiple primary power modules can be connected in series or parallel, enabling the switching power supply to develop towards a wider input voltage and a larger power.

[0025] 3. The present invention can widen the input voltage by increasing the number of series-connected primary power modules, enabling the switching power supply to adapt to applications under different requirements. Description of the Drawings

[0026] Figure 1 It is the valley filling circuit diagram of the prior art;

[0027] Figure 2 It is a schematic diagram of a switching power supply provided in the Chinese patent document with the publication number CN217240580U;

[0028] Figure 3 It is the circuit diagram of the first embodiment of the module valley filling circuit of the present invention;

[0029] Figure 4 It is the circuit diagram of the second embodiment of the module valley filling circuit of the present invention;

[0030] Figure 5 It is the circuit diagram of the third embodiment of the module valley filling circuit of the present invention;

[0031] Figure 6 It is the circuit diagram of the fourth embodiment of the module valley filling circuit of the present invention;

[0032] Figure 7 It is the circuit diagram of the fifth embodiment of the module valley filling circuit of the present invention;

[0033] Figure 8 It is the circuit diagram of the sixth embodiment of the module valley filling circuit of the present invention. Detailed Embodiments

[0034] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0035] It should be noted that the terms "including" and "having" and any variations thereof described in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, a series of components, unit circuits, or control timings included do not necessarily have to be limited to those clearly listed, but may include those not clearly listed or components, unit circuits, or control timings inherent to these circuits.

[0036] In addition, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0037] It should be understood that in the specification and claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element or "connected" to the other element through a third element.

[0038] An embodiment of the present invention provides a module valley filling circuit, including M primary power modules and N valley filling circuits, where M is a natural number greater than or equal to 2, and N is a natural number greater than or equal to 1 and less than M;

[0039] The primary power modules are connected to each other through the valley filling circuits. The valley filling circuit includes a diode, an upper valley filling tube, and a lower valley filling tube. The first end of the upper valley filling tube is connected to the positive input terminal of any one of the 1st to the i-th primary power modules. The first end of the lower valley filling tube is connected to the negative input terminal of any one of the 1st to the i-th primary power modules. The negative input terminal of the i-th primary power module is connected to the anode of the diode. The positive input terminal of the (i + 1)-th primary power module is respectively connected to the cathode of the diode and the second end of the upper valley filling tube. The negative input terminal of the (i + 1)-th primary power module is connected to the second end of the lower valley filling tube; where 1 ≤ i ≤ M - 1 and i is a positive integer.

[0040] The drain of the switching tube in the primary power module is connected to the positive electrode of the capacitor as the positive input terminal of the primary power module;

[0041] Or, the primary winding is connected to the positive electrode of the capacitor as the positive input terminal of the primary power module;

[0042] Or, the source of the switching tube is connected to the negative terminal of the capacitor as the negative input terminal of the primary power module;

[0043] Or, the primary winding is connected to the negative electrode of the capacitor as the negative input terminal of the primary power module.

[0044] Among them, all the switching tubes, valley filling tubes, and diodes can be metal-oxide-semiconductor field-effect transistors (MOSFETs), or other types of switching devices can also be used.

[0045] Furthermore, the turns ratio of all the primary windings to the secondary windings of the transformers in the corresponding primary power modules is the same.

[0046] Furthermore, the number of turns of the secondary windings in all the secondary power modules is the same.

[0047] In the module valley filling circuit of this embodiment, the number of primary power modules can be increased to achieve the effect of broadening the input voltage, making its application scenarios more extensive. The following is an example to illustrate the expansion method. It should be noted that the following examples should not be regarded as limiting the protection scope of the present invention. Those skilled in the art can select the values of M and N and the connection method of the output terminals of each primary power module according to the actual application scenarios.

[0048] The first embodiment:

[0049] Figure 3 It is the circuit schematic diagram of an embodiment of the module valley filling circuit of the present invention, where M = 3 and N = 2. Its composed circuit is as follows:

[0050] The switching power supply includes three primary power modules, two valley filling circuits, and one secondary power module; the first primary power module includes a primary winding L1, a capacitor C1, and a switching tube Q1; the second primary power module includes a primary winding L2, a capacitor C2, and a switching tube Q3; the third primary power module includes a primary winding L3, a capacitor C3, and a switching tube Q4; the first valley filling circuit includes a diode D1, an upper valley filling tube Q6, and a lower valley filling tube Q2; the second valley filling circuit includes a diode D2, an upper valley filling tube Q7, and a lower valley filling tube Q5; the secondary power module includes a diode D3, a capacitor C4, and a secondary winding L4;

[0051] Specifically, the positive electrode of the capacitor C1 is connected to the drain of the switching tube Q1, the drain of the upper valley filling tube Q6, and the drain of the upper valley filling tube Q7, serving as the positive input terminal of the first primary power module; the negative electrode of the capacitor C1 is connected to the opposite name end of the primary winding L1, the anode of the diode D1, the drain of the lower valley filling tube Q5, and the drain of the lower valley filling tube Q2, serving as the negative input terminal of the first primary power module; the source of the switching tube Q1 is connected to the same name end of the primary winding L1; the positive electrode of the capacitor C2 is connected to the drain of the switching tube Q3, the source of the upper valley filling tube Q6, and the cathode of the diode D1, serving as the positive input terminal of the second primary power module; the negative electrode of the C2 capacitor is connected to the source of the lower valley filling tube Q2, the opposite name end of the primary winding L2, and the anode of the diode D2, serving as the negative input terminal of the second primary power module; the source of the switching tube Q3 is connected to the same name end of the primary winding L2; the positive electrode of the capacitor C3 is connected to the drain of the switching tube Q4, the source of the upper valley filling tube Q7, and the cathode of the diode D2, serving as the positive input terminal of the third primary power module; the negative electrode of the C3 capacitor is connected to the source of the lower valley filling tube Q5 and the opposite name end of the primary winding L3, serving as the negative input terminal of the third primary power module; the opposite name end of the secondary winding L4 is connected to the anode of the diode D3, the same name end of the secondary winding L4 is connected to the negative electrode of the capacitor C4, and the cathode of the diode D3 is connected to the positive electrode of the capacitor C4.

[0052] The specific working principle of this embodiment is:

[0053] Mode 1: When the input voltage is higher than the threshold value Vh of the product input monitoring circuit, the valley-filling tubes Q2, Q5, Q6, and Q7 remain normally open, and the capacitors C1, C2, and C3 are connected in series through diodes D1 and D2. When the switch tubes Q1, Q3, and Q4 are turned on at the same time (the driving signals are consistent), the capacitor C1 is excited and stored through the primary winding L1, the capacitor C2 is excited and stored through the primary winding L2, the capacitor C1 is excited and stored through the primary winding L1, and the capacitor C3 is excited and stored through the primary winding L3. When the switch tubes Q1, Q3, and Q4 are turned off at the same time, the excitation energy is released through the secondary winding L4, charging the output capacitor C4 and providing energy to the output end. The energy stored during the on-time of the switch tube is consumed.

[0054] Mode 2: When the input voltage is lower than the threshold value Vh of the product input monitoring circuit, the valley-filling tubes Q2, Q5, Q6, and Q7 remain normally closed, and the capacitors C1, C2, and C3 are connected in parallel through the valley-filling tubes Q2, Q5, Q6, and Q7. When the switch tubes Q1, Q3, and Q4 are turned on at the same time (the driving signals are consistent), the capacitor C1 is excited and stored through the primary winding L1, the capacitor C2 is excited and stored through the primary winding L2, the capacitor C1 is excited and stored through the primary winding L1, and the capacitor C3 is excited and stored through the primary winding L3. When the switch tubes Q1, Q2, and Q4 are turned off at the same time, the excitation energy is released through the secondary winding L4, charging the output capacitor C4 and providing energy to the output end. The energy stored during the on-time of the switch tube is consumed.

[0055] in, Figure 3 Each secondary circuit of the circuit shown is used to rectify and filter the energy transmitted by the corresponding transformer and then output it. Figure 3 In addition to the specific circuit shown, a synchronous rectification method can also be used for rectification and filtering, and this embodiment does not limit the specific secondary circuit used.

[0056] Likewise, Figure 3 The switch tubes Q1, Q2, Q3, Q4, Q5, Q6, Q7 and the diodes D1, D2 in the circuit shown can be metal oxide semiconductor transistors (MOSFETs), or other types of switch devices can be used. The specific switch device used is not limited in this embodiment.

[0057] Likewise, Figure 3 Each primary winding in the circuit shown may correspond to a transformer, or may be combined into one transformer, and the effect is to achieve transformer demagnetization, and the specific implementation of this embodiment is not limited.

[0058] Second embodiment:

[0059] Figure 4This is the circuit schematic diagram of an embodiment of the valley filling circuit of the present invention, where M = 2 and N = 1. The composed circuit is as follows:

[0060] The switching power supply includes two primary power modules, a valley filling circuit and a secondary power module; the first primary power module includes a primary winding P11, a capacitor C1, a switching transistor Q1, a freewheeling diode D1 and a demagnetized primary winding P12; the second primary power module includes a primary winding P13, a capacitor C2, a switching transistor Q2, a freewheeling diode D2 and a demagnetized primary winding P14; the valley filling circuit includes an upper valley filling transistor Q4, a lower valley filling transistor Q3 and a valley filling diode D3; the secondary power module includes diodes D4, D5, an output capacitor C3 and a storage inductor L1;

[0061] Specifically, the positive electrode of the capacitor C1 is connected to the same-name end of the primary winding P11, the drain of the control switching transistor Q4, and the different-name end of the primary winding P12, serving as the positive input terminal of the switching power supply; the negative electrode of the capacitor is connected to the source of the switching transistor Q1, the anodes of the diodes D1 and D3, and the drain of the control switching transistor Q3, serving as the negative input terminal of the first primary power module. The drain of the switching transistor Q1 is connected to the different-name end of the primary winding P11, and the cathode of the diode D1 is connected to the same-name end of the primary winding P12; the positive electrode of the capacitor C2 is connected to the same-name end of the primary winding P13, the source of the control switching transistor Q4, the cathode of the diode D3, and the different-name end of the primary winding P14, serving as the input terminal of the second primary power module; the negative electrode of the capacitor is connected to the source of the control switching transistor Q3, the source of the switching transistor Q2, and the anode of the diode D2, serving as the output terminal of the second primary power module and the ground of the switching power supply. The drain of the switching transistor Q2 is connected to the different-name end of the primary winding P13, and the cathode of the diode D2 is connected to the same-name end of the primary winding; the same-name end of the secondary winding P2 is connected to the anode of the diode D4, the cathode of the diode D4 is connected to the cathode of the diode D5 and the same-name end of the inductor L1, the different-name end of the inductor L1 is connected to the positive electrode of the capacitor C3, and the different-name end of the secondary winding P2 is connected to the negative electrode of the capacitor C3 and the anode of the diode D5.

[0062] The specific working principle of this embodiment is as follows:

[0063] Mode 1: When the input voltage is higher than the threshold value Vh of the product input monitoring circuit, the switch tubes Q3 and Q4 remain normally open, and the two capacitors C16 and C15 are connected in series to divide the voltage through D18. When the switch tubes Q1 and Q2 are turned on at the same time (the driving signals are the same), the capacitor C1 is excited through the primary winding P11, and the capacitor C2 is excited through the primary winding P13. The excitation energy is released through the same-name end of the secondary winding P2 of the transformer T1, storing energy in the inductor L1 and charging the output capacitor C3, while providing energy to the output end; when the switch tubes Q1 and Q2 are turned off at the same time, the transformer is demagnetized through the primary windings P12 and P14, and the energy storage inductor L1 charges C3 until the transformer is demagnetized.

[0064] Mode 2: When the input voltage is lower than the threshold value Vh of the product input monitoring circuit, the switch tube Q3 and the switch tube Q4 remain normally closed, and the two capacitors C16 and C15 are connected in parallel by controlling the switch tubes Q3 and Q4. When the switch tubes Q1 and Q2 are turned on at the same time (the driving signals are consistent), the capacitor C1 is excited through the primary winding P11, and the capacitor C2 is excited through the primary winding P13. The excitation energy is released through the same-name end of the secondary winding P2 of the transformer T1, storing energy in the inductor L1 and charging the output capacitor C3, while providing energy to the output end; when the switch tubes Q1 and Q2 are turned off at the same time, the transformer is demagnetized through the primary windings P12 and P14, and the energy storage inductor L1 charges C3 until the transformer is demagnetized.

[0065] in, Figure 4 Each secondary circuit of the circuit shown is used to rectify and filter the energy transmitted by the corresponding transformer and then output it. Figure 3 In addition to the specific circuit shown, a synchronous rectification method can also be used for rectification and filtering, and this embodiment does not limit the specific secondary circuit used.

[0066] Likewise, Figure 4 The switch tubes Q1, Q2, Q3, Q4 and the diodes D1, D2, D3, D4 in the circuit shown can be metal oxide semiconductor transistors (MOSFETs), or other types of switch devices can be used. The specific switch device used is not limited in this embodiment.

[0067] Likewise, Figure 4 Each primary winding in the circuit shown may correspond to a transformer, or may be combined into one transformer, and the effect is to achieve transformer demagnetization, and the specific implementation of this embodiment is not limited.

[0068] Similarly, in theory Figure 4 It is also possible to realize the serial connection of an infinite number of primary power modules by adding N identical primary power modules and connecting them using N-1 valley-filling circuits.

[0069] Figure 5For another embodiment of the present invention, its specific principle is the same as that of Figure 4 Similar. For each primary power module of the power supply module, the topology of the primary power module is a double-switch forward converter. The primary switching tubes are Q1, Q2, Q4, and Q5, and the valley-fill tubes are Q6 and Q7. The primary power module includes a primary winding P11, a capacitor C1, a switching tube Q1, a switching tube Q2, a diode D1, and a diode D2. The first end of the capacitor C1 is respectively connected to the cathode of the diode D1 and the first end of the switching tube Q1. The anode of the diode D1 is respectively connected to the opposite-named end of the primary winding P11 and the first end of the switching tube Q2. The second end of the switching tube Q1 is respectively connected to the same-named end of the primary winding P11 and the cathode of the diode D2. The anode of the diode and the second end of the switching tube Q2 are both connected to the capacitor C1. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C1 serves as the negative input terminal of the primary power module. Its working principle is the same as that of Figure 4 The circuit principle is similar. Only the demagnetization of the transformer is achieved through the self-excited demagnetization of the primary winding, which will not be elaborated here.

[0070] Figure 6 For another embodiment of the present invention, for each primary power module of the power supply module, the topology of the primary power module is a half-bridge LLC. The primary switching tubes are Q1, Q2, Q3, and Q4, the valley-fill tubes are Q5 and Q6, and the valley-fill diode is D1. The primary power module includes a primary winding P11, a capacitor C1, a capacitor Cr1, an inductor Lr1, a switching tube Q1, and a switching tube Q2. The first end of the capacitor C1 is connected to the first end of the switching tube Q1. The second end of the switching tube Q1 is connected to the first end of the switching tube Q2. The second end of the switching tube Q1 is connected to the same-named end of the primary winding P11 through the inductor Lr1. The opposite-named end of the primary winding P11 is connected to the first end of the capacitor Cr1. The second end of the switching tube Q2 and the second end of the capacitor Cr1 are both connected to the second end of the capacitor C1. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C1 serves as the negative input terminal of the primary power module. Its working principle is the same as that of Figure 4 The difference is that the lossless turn-on and turn-off of each switching tube are realized by using the LC resonance principle, and the secondary power circuit adopts a synchronous rectification scheme (without a storage inductor), which will not be elaborated here.

[0071] Figure 7For another embodiment of the present invention, the topology of each primary power module in the primary side of the power module is a three-level LLC. The primary switching transistors are Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8. The valley-fill transistors are Q9 and Q10, and the valley-fill diode is D1. The primary power module includes a primary winding P11, a capacitor C1, a resistor R1, a resistor R2, a resistor R3, a zener diode Z1, a switching transistor Q1, and a switching transistor Q2. The first end of the capacitor C1 is respectively connected to the first end of the resistor R1 and the same-name end of the primary winding P11. The second end of the resistor R1 is connected to the cathode of the zener diode Z1. The second end of the resistor R1 is connected to the control end of the switching transistor Q1 through the resistor R2. The different-name end of the primary winding P11 is connected to the first end of the switching transistor Q1. The second end of the switching transistor Q1 is connected to the first end of the switching transistor Q2. The control end of the switching transistor Q2 is connected to the resistor R3. The anode of the voltage regulator Z1 and the second end of the switching transistor Q2 are both connected to the second end of the capacitor C1. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C1 serves as the negative input terminal of the primary power module. Its working principle is similar to that of Figure 6 and will not be elaborated here.

[0072] Figure 8 For another embodiment of the present invention, the topology of each primary power module in the primary side of the power module is a double-switch series flyback. The primary switching transistors are Q1, Q2, Q3, and Q4. The valley-fill transistors are Q5 and Q6, and the valley-fill diode is D1. The primary power module includes a primary winding P11, a capacitor C1, a capacitor C2, a capacitor Cr1, an inductor Lr1, a switching transistor Q1, a switching transistor Q2, a switching transistor Q3, and a switching transistor Q4. The first end of the capacitor C1 is connected to the first end of the switching transistor Q1. The second end of the switching transistor Q1 is connected to the first end of the switching transistor Q2. The second end of the switching transistor Q1 is sequentially connected to the same-name end of the primary winding P11 through the capacitor Cr1 and the inductor Lr1. The second end of the capacitor C1 is respectively connected to the second end of the switching transistor Q2, the first end of the switching transistor Q3, and the first end of the capacitor C2. The different-name end of the primary winding P11 is respectively connected to the second end of the switching transistor Q3 and the first end of the switching transistor Q4. The second end of the switching transistor Q4 is connected to the second end of the capacitor C2. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C2 serves as the negative input terminal of the primary power module. Its working principle is similar to that of Figure 3 and will not be elaborated here.

[0073] The above are only exemplary embodiments of the present invention. It should be particularly noted that the above embodiments should not be regarded as limitations on the present invention. For those of ordinary skill in the art, without departing from the spirit and scope of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A module valley filling circuit, characterized in that: It includes M primary-side power modules and N valley-fill circuits, where M is a natural number greater than or equal to 2, and N is a natural number greater than or equal to 1 and less than M; Each of the primary-side power modules is connected through the valley-fill circuit. The valley-fill circuit includes a diode, an upper valley-fill tube, and a lower valley-fill tube. The first end of the upper valley-fill tube is connected to the positive input terminal of any one of the first to the i-th primary-side power modules, and the first end of the lower valley-fill tube is connected to the negative input terminal of any one of the first to the i-th primary-side power modules. The negative input terminal of the i-th primary-side power module is connected to the anode of the diode, and the positive input terminal of the (i + 1)-th primary-side power module is respectively connected to the cathode of the diode and the second end of the upper valley-fill tube. The negative input terminal of the (i + 1)-th primary-side power module is connected to the second end of the lower valley-fill tube; where 1 ≤ i ≤ M - 1 and i is a positive integer.

2. The module valley filling circuit according to claim 1, wherein: Each of the primary-side power modules includes a capacitor C1, a switching tube Q1, and a primary-side winding L1. The first end of the capacitor C1 and the first end of the switching tube Q1 are connected together and used as the positive input terminal of the primary-side power module. The second end of the switching tube Q1 is connected to the same-name end of the primary-side winding L1, and the second end of the capacitor C1 and the different-name end of the primary-side winding L1 are connected as the negative input terminal of the primary-side power module.

3. The module valley filling circuit according to claim 1, wherein: The primary-side power module includes a primary-side winding P11, a capacitor C1, a switching tube Q1, a diode D1, and a primary-side winding P12. The first end of the capacitor C1 is respectively connected to the same-name end of the primary-side winding P11 and the different-name end of the primary-side winding P12. The different-name end of the primary-side winding P11 is connected to the first end of the switching tube Q1. The same-name end of the primary-side winding P12 is connected to the cathode of the diode D1. The second end of the capacitor C1 is respectively connected to the second end of the switching tube Q1 and the anode of the diode D1. The first end of the capacitor C1 is used as the positive input terminal of the primary-side power module, and the second end of the capacitor C1 is used as the negative input terminal of the primary-side power module.

4. The module valley filling circuit according to claim 1, wherein: The primary-side power module includes a primary-side winding P11, a capacitor C1, a switching tube Q1, a switching tube Q2, a diode D1, and a diode D2. The first end of the capacitor C1 is respectively connected to the cathode of the diode D1 and the first end of the switching tube Q1. The anode of the diode D1 is respectively connected to the different-name end of the primary-side winding P11 and the first end of the switching tube Q2. The second end of the switching tube Q1 is respectively connected to the same-name end of the primary-side winding P11 and the cathode of the diode D2. The anode of the diode and the second end of the switching tube Q2 are both connected to the capacitor C1. The first end of the capacitor C1 is used as the positive input terminal of the primary-side power module, and the second end of the capacitor C1 is used as the negative input terminal of the primary-side power module.

5. The module valley filling circuit according to claim 1, wherein: The primary power module includes a primary winding P11, a capacitor C1, a capacitor Cr1, an inductor Lr1, a switching transistor Q1, and a switching transistor Q2. A first end of the capacitor C1 is connected to a first end of the switching transistor Q1. A second end of the switching transistor Q1 is connected to a first end of the switching transistor Q2. The second end of the switching transistor Q1 is connected to a corresponding end of the primary winding P11 through the inductor Lr1. A non-corresponding end of the primary winding P11 is connected to a first end of the capacitor Cr1. A second end of the switching transistor Q2 and a second end of the capacitor Cr1 are both connected to a second end of the capacitor C1. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C1 serves as the negative input terminal of the primary power module.

6. The module valley filling circuit according to claim 1, wherein: The primary power module includes a primary winding P11, a capacitor C1, a resistor R1, a resistor R2, a resistor R3, a zener diode Z1, a switching transistor Q1, and a switching transistor Q2. The first end of the capacitor C1 is respectively connected to the first end of the resistor R1 and the corresponding end of the primary winding P11. The second end of the resistor R1 is connected to the cathode of the zener diode Z1. The second end of the resistor R1 is connected to the control terminal of the switching transistor Q1 through the resistor R2. The non-corresponding end of the primary winding P11 is connected to the first end of the switching transistor Q1. The second end of the switching transistor Q1 is connected to the first end of the switching transistor Q2. The control terminal of the switching transistor Q2 is connected to the resistor R3. The anode of the voltage regulator Z1 and the second end of the switching transistor Q2 are both connected to the second end of the capacitor C1. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C1 serves as the negative input terminal of the primary power module.

7. The module valley filling circuit according to claim 1, wherein: The primary power module includes a primary winding P11, a capacitor C1, a capacitor C2, a capacitor Cr1, an inductor Lr1, a switching transistor Q1, a switching transistor Q2, a switching transistor Q3, and a switching transistor Q4. The first end of the capacitor C1 is connected to the first end of the switching transistor Q1. The second end of the switching transistor Q1 is connected to the first end of the switching transistor Q2. The second end of the switching transistor Q1 is sequentially connected to the corresponding end of the primary winding P11 through the capacitor Cr1 and the inductor Lr1. The second end of the capacitor C1 is respectively connected to the second end of the switching transistor Q2, the first end of the switching transistor Q3, and the first end of the capacitor C2. The non-corresponding end of the primary winding P11 is respectively connected to the second end of the switching transistor Q3 and the first end of the switching transistor Q4. The second end of the switching transistor Q4 is connected to the second end of the capacitor C2. The first end of the capacitor C1 serves as the positive input terminal of the primary power module, and the second end of the capacitor C2 serves as the negative input terminal of the primary power module.

8. The module valley filling circuit according to claim 1, wherein: The upper valley filling transistor and the lower valley filling transistor are turned on or off simultaneously.

9. The module valley filling circuit according to claim 1, wherein: The turns ratio of the primary winding in the primary power module is the same as that of the secondary winding of the corresponding transformer.

10. A switching power supply, characterized in that: The switching power supply includes the module valley filling circuit according to any one of claims 1-9.

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