Multi-channel self-adaptive input auxiliary switching power supply

Abstract

The invention discloses a multipath self-adaptive input auxiliary switching power supply, and belongs to the technical field of switching power supplies. The switching power supply comprises a multi-primary-side transformer with N primary-side windings and a secondary-side winding, and each input voltage source is connected to the corresponding primary-side winding and outputs a voltage signal by sharing the secondary-side winding. Each group of input voltage sources is connected with one group of power management modules, MOS tube driving signals output by the power management modules are connected with grid electrodes of high-voltage MOS tubes through high-voltage MOS tube driving modules, and a voltage stress absorption module is arranged between drain electrodes of the high-voltage MOS tubes and a primary winding and is used for restraining the voltage stress problem caused by simultaneous input of alternating voltage and direct voltage. The secondary winding output end of the transformer is connected with the output rectifying and filtering module; and each group of power management modules is also connected with the output end through an independent feedback module. The auxiliary switching power supply is compact in structure, flexible in input and high in efficiency, and the auxiliary source cost and space occupation are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of switching power supplies, and in particular to an auxiliary switching power supply with multi-channel adaptive inputs. Background Art

[0002] In recent years, with the rapid development of China's new energy industry, the industry has placed higher demands on the technical performance of new energy equipment, particularly in terms of system stability, operational efficiency, control flexibility, and cost control. To meet startup requirements under different operating conditions and avoid system paralysis due to single point failures, the control systems in new energy power plants such as photovoltaic power plants, wind farms, and energy storage systems generally need to be able to obtain power from multiple energy sources.

[0003] Common power sources include primary power sources (such as photovoltaic arrays), the grid, batteries, and diesel generators. To ensure stable power draw from these multiple energy sources, existing technologies often employ multiple auxiliary switching power supplies connected to different energy nodes to ensure reliable control system operation under various operating conditions.

[0004] However, deploying multiple independent auxiliary switching power supplies in new energy systems also presents a series of problems and challenges. First, hardware costs increase significantly. Because each auxiliary switching power supply requires a complete power conversion circuit and related electronic components, the use of multiple auxiliary switching power supplies directly increases the overall material cost.

[0005] Secondly, the system's operating efficiency decreases. In most operating states, only one auxiliary switching power supply is actually working, while the rest are in standby or redundant mode. This not only increases the number of energy conversion links but also reduces the overall operating efficiency of the system.

[0006] Finally, multiple sets of auxiliary switching power supplies occupy a large PCB space, increasing the complexity of the internal layout design of the equipment, which is not conducive to the miniaturization and integration of the equipment and limits the application adaptability of the product in a compact space environment.

[0007] In summary, there is an urgent need to propose a multi-channel adaptive input auxiliary switching power supply design scheme with reasonable structure, controllable cost, high efficiency and high space utilization, so as to effectively solve the technical bottleneck brought by multiple sets of auxiliary switching power supplies in new energy systems and improve the overall performance and market competitiveness of new energy equipment. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: in response to the above-mentioned defects of the prior art, an auxiliary switching power supply with multi-channel adaptive input is provided, which effectively reduces costs, ensures working stability, improves the efficiency of the auxiliary switching power supply, saves internal space of the equipment, and meets the current design requirements of new energy auxiliary switching power supplies.

[0009] To achieve the above object, the present invention provides an auxiliary switching power supply with multi-channel adaptive input, the auxiliary switching power supply comprising a multi-primary transformer and N groups of input voltage sources;

[0010] The multi-primary transformer has N primary windings and one secondary winding; the N groups of input voltage sources are respectively connected to corresponding primary windings, and each primary winding outputs a voltage signal through the secondary winding;

[0011] Each set of input voltage sources is connected to a set of power management modules. The power input terminals of the power management modules are connected to the corresponding input voltage sources. The MOS transistor drive signals output by the power management modules are connected to the gates of the high-voltage MOS transistors via the MOS transistor drive modules. The drains of the high-voltage MOS transistors are connected to the primary winding via voltage stress absorption modules. The voltage stress absorption modules are used to reduce the voltage stress caused by the simultaneous input of AC and DC voltage sources into a single transformer.

[0012] The output end of the secondary winding is connected to an output rectifier and filter module, and the output rectifier and filter module is used to rectify and filter the output voltage of the secondary side of the transformer;

[0013] Each group of power management modules is connected to the output end of the rectification and filtering module through an independent feedback module.

[0014] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the power management module includes a power management chip, a zero-crossing detection circuit connected to the zero-crossing detection pin of the power management chip, and a soft-start circuit connected to the VCC power pin of the power management chip, and the soft-start circuit is connected to the input voltage source.

[0015] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the multi-primary transformer also includes N auxiliary windings, and the N primary windings have the same winding direction; the winding direction of the auxiliary windings and the secondary windings is opposite to that of the primary windings; the auxiliary windings are connected to the zero-crossing detection pin of the power management chip through the zero-crossing detection circuit, and are also connected to the VCC power pin of the power management chip through the soft start circuit.

[0016] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the voltage stress absorption module includes a decoupling diode, the anode of the decoupling diode is connected to the primary winding, and the cathode of the decoupling diode is connected to the drain of the high-voltage MOS tube.

[0017] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the feedback module includes a three-terminal voltage regulator and an optocoupler.

[0018] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the MOS tube driving module includes a push-pull circuit.

[0019] In the auxiliary switching power supply with multi-channel adaptive input of the present invention, the output rectification and filtering module includes a rectifier diode, an output filtering capacitor, and a load resistor.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1. Significantly Reduced System Cost: By integrating multiple traditional auxiliary switching power supplies into a single circuit structure, multiple transformers and their corresponding peripheral components, such as output rectification, filtering, and pre-load resistors, are eliminated. Compared to traditional discrete auxiliary power supply structures, this invention significantly reduces the number of components, effectively reducing material and manufacturing costs.

[0022] 2. Effectively Reduce Device Size and Optimize Spatial Layout: This invention utilizes a transformer structure with multiple inputs sharing a secondary winding, allowing previously dispersed auxiliary power sources to be integrated onto a single circuit board, significantly reducing the overall size of the auxiliary power module. This not only saves internal device space but also provides more possibilities for the rational arrangement of other key components, facilitating the miniaturization and compactness of new energy equipment.

[0023] 3. Improve overall system efficiency: By eliminating multiple rectification and filtering components on the secondary side of the transformer, the corresponding conduction loss and static power consumption are reduced. At the same time, the redundant loss caused by the parallel operation of multiple auxiliary power sources is avoided, thereby significantly improving the working efficiency and energy conversion rate of the auxiliary switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a structural block diagram of the flyback power supply of the present invention.

[0026] Figure 2 4 is a circuit diagram of the main power topology of an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of a power management chip and its peripheral circuits according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of a high-voltage MOS tube driving circuit according to an embodiment of the present invention.

[0029] Figure 5This is a simulation diagram of the DC MOS tube voltage stress when the power supply is started without adding a decoupling diode.

[0030] Figure 6 This is a simulation diagram of the DC MOS tube voltage stress when the power supply is started when a decoupling diode is added.

[0031] Figure 7 It is a circuit schematic diagram of the main power topology of multiple groups of auxiliary switching power supplies. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] The general idea of ​​the present invention is to simultaneously input multiple groups of input power into multiple primary transformers, adopt a single secondary output, and use a voltage stress absorption module to solve the voltage stress problem caused by simultaneous AC and DC input into a single transformer.

[0034] The embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0035] An embodiment of the present invention provides an auxiliary switching power supply with multi-channel adaptive input, the auxiliary switching power supply comprising a multi-primary transformer and N groups of input voltage sources;

[0036] The multi-primary transformer has N primary windings and one secondary winding; the N groups of input voltage sources are respectively connected to corresponding primary windings, and each primary winding outputs a voltage signal through the secondary winding;

[0037] Each set of input voltage sources is connected to a set of power management modules. The power input terminals of the power management modules are connected to the corresponding input voltage sources. The MOS transistor drive signals output by the power management modules are connected to the gates of the high-voltage MOS transistors via the MOS transistor drive modules. The drains of the high-voltage MOS transistors are connected to the primary winding via voltage stress absorption modules. The voltage stress absorption modules are used to reduce the voltage stress caused by the simultaneous input of AC and DC voltage sources into a single transformer.

[0038] The output end of the secondary winding is connected to an output rectifier and filter module, and the output rectifier and filter module is used to rectify and filter the output voltage of the secondary side of the transformer;

[0039] Each group of power management modules is connected to the output end of the rectification and filtering module through an independent feedback module.

[0040] In an embodiment of the present invention, different input voltage sources are connected to different primary windings of multiple primary transformers, and share a secondary winding for output. The voltage stress caused by the AC and DC voltage sources being simultaneously input into a single transformer is reduced through a voltage stress absorption module. Compared with a solution in which each input voltage source is connected to an independent transformer, the number of transformers and the number of rectifier and filter modules are reduced, effectively reducing the size of the auxiliary switching power supply, which is beneficial to saving space inside the device, reserving more space for the arrangement of other devices, reducing the loss caused by secondary components, and thereby improving the overall efficiency of the auxiliary switching power supply.

[0041] In an embodiment of the present invention, the power management module includes a power management chip, a zero-crossing detection circuit connected to the zero-crossing detection pin of the power management chip, and a soft-start circuit connected to the VCC power pin of the power management chip, and the soft-start circuit is connected to the input voltage source.

[0042] The power management chip can also have built-in overvoltage detection circuit, overcurrent detection circuit and low-power timing capacitor.

[0043] In an embodiment of the present invention, the multi-primary transformer also includes N auxiliary windings, and the N primary windings have the same winding direction; the winding direction of the auxiliary winding and the secondary winding is opposite to that of the primary winding; the auxiliary winding is connected to the zero-crossing detection pin of the power management chip through the zero-crossing detection circuit, and is also connected to the VCC power pin of the power management chip through the soft start circuit.

[0044] The power management chip uses the zero-crossing point of the auxiliary winding voltage to determine the onset of resonance, thereby inferring the valley position of the high-voltage MOS transistor's Vds resonant voltage, achieving valley capture and low-loss turn-on. The voltages of multiple primary windings cross zero at the same moment, controlling the simultaneous turn-on of multiple high-voltage MOS transistors. The input voltage source charges the capacitor in the soft-start circuit, bringing the power management chip to the startup voltage and entering normal operation. The auxiliary winding then maintains the operating voltage at the power management chip's VCC power pin.

[0045] In an embodiment of the present invention, the voltage stress absorption module includes a decoupling diode, the anode of which is connected to the primary winding, and the cathode of which is connected to the drain of the high-voltage MOS transistor. The decoupling diode is used to isolate the feedback loops of different primary sides, ensuring the normal operation of the flyback power supply under different operating conditions, while effectively reducing the extreme stress on the MOS transistor under certain operating conditions.

[0046] In an embodiment of the present invention, the feedback module includes a three-terminal voltage regulator and an optocoupler. The feedback module in this embodiment of the present invention is a type III compensator based on AZ431 and also includes components such as capacitors and resistors. The feedback module is used to compensate for zeros and poles in the switching power supply control loop, ensuring that the switching power supply has sufficient amplitude margin and phase margin to meet the dynamic and static performance requirements of the flyback switching power supply. The input voltage is reflected in the numerator of the switching power supply power stage transfer function. This means that the input voltage is positively correlated with the DC gain of the switching power supply (only for buck topologies): the higher the input voltage, the greater the DC gain. To properly control the position of the open-loop gain crossover frequency, assuming that different system input voltages share the same feedback loop (i.e., the same parameter design), the open-loop gain crossover frequency of the feedback loop corresponding to a particular input voltage may be shifted to a position that causes system instability. Therefore, different capacitor and resistor parameter designs are required for the feedback modules corresponding to different input voltage sources. This allows for determining optimal loop compensation parameters based on different input voltage ranges to ensure good dynamic response of the auxiliary switching power supply.

[0047] In an embodiment of the present invention, the MOS transistor driving module includes a push-pull circuit. The push-pull structure can enhance the driving capability of the power management chip, increase the driving voltage, and enable the MOS transistor to operate at a lower on-resistance position, thereby reducing conduction loss.

[0048] In the embodiment of the present invention, the output rectifier and filter module includes a rectifier diode, an output filter capacitor, and a load resistor. The main function of the output filter module is to stabilize the output voltage.

[0049] Example

[0050] This embodiment is a dual-path adaptive input auxiliary switching power supply suitable for energy storage inverters. The energy storage inverter needs to be able to draw power from both the grid side and the battery side, so it is designed with two inputs, where the battery is a DC input and the grid side is an AC input. The structural framework of the auxiliary switching power supply of this embodiment is as follows: Figure 1 As shown, the specific circuit is as follows Figures 2 to 4 shown. Figure 2 is a circuit diagram of the main power topology of this embodiment, Figure 3 This is a schematic diagram of a power management chip and its peripheral circuits according to an embodiment of the present invention. Figure 4 This is the schematic diagram of the high-voltage MOS tube drive circuit.

[0051] like Figure 1As shown, both the AC input and the DC input are connected to the primary input of the multi-primary transformer, the output of the multi-primary transformer is connected to the output rectifier and filter module, the AC input is connected to the multi-primary transformer via the power management module, the MOS tube driver module, the high-voltage MOS tube, and the voltage stress absorption module, and the two power management modules are connected to the two feedback modules respectively.

[0052] like Figure 2 As shown, the main power topology circuit schematic includes a multi-primary transformer TX1, which includes an AC input primary winding P1, an AC auxiliary winding S2, a DC input primary winding P2, a DC auxiliary winding S3, and a secondary winding S1. The AC input primary winding P1 and the DC input primary winding P2 have the same winding direction, while the secondary windings S1, AC auxiliary winding S2, and DC auxiliary winding S3 have the same winding direction and are opposite to those of the AC input primary winding P1 and the DC input primary winding P2. One end of the AC input primary winding P1 and the DC input primary winding P2 are connected to the AC and DC inputs, respectively, and the other end is connected to the voltage stress absorption module. The secondary winding S1 is connected to the output rectifier and filter module. The AC auxiliary winding S2 and DC auxiliary winding S3 are connected to the power management chip and its peripheral circuits. In addition to serving as a transformer in a conventional flyback switching power supply, the multi-primary transformer couples the energy of the AC and DC inputs and outputs it through a single secondary winding.

[0053] Continue to refer to Figure 2 The high-voltage MOS transistor corresponding to the AC input is the second MOS transistor Q2, and the high-voltage MOS transistor corresponding to the DC input is the first MOS transistor Q1. The voltage stress absorption module includes a voltage absorption module for the MOS transistor on the AC input side, consisting of a first resistor R1, a first capacitor C1, a first diode D1, and a third diode D3; and a voltage absorption module for the MOS transistor on the DC input side, consisting of a fourth resistor R4, a second diode D2, a second capacitor C2, and a fourth diode D4. The principle of a conventional RCD absorption module is that when the MOS transistor is turned off, energy is stored in the primary winding of the transformer. Because the current cannot change suddenly, the leakage inductance generates a high-voltage spike. The capacitor provides a low-impedance path to limit the current rise, and the energy is then discharged through the resistor, effectively suppressing the voltage spike. Because the transformer in this embodiment has two different inputs and uses different MOS transistors to control the energy input, there may be a certain phase difference between the turning on and off of the two MOS transistors during the startup phase of the power supply, which in turn causes more severe voltage stress on the MOS transistors.

[0054] The voltage stress absorption module of this embodiment is based on the commonly used RCD absorption, and a decoupling diode ( Figure 2The third diode D3 and the fourth diode D4 in the decoupling diode are connected, the anode of the decoupling diode is connected to the primary winding, and the cathode is connected to the drain of the high-voltage MOS tube, thereby effectively reducing the voltage stress of the MOS tube.

[0055] Below is Figure 2 Take this example to illustrate the necessity of adding decoupling diodes. Assuming the two primary windings have the same number of turns, when both the first and second MOS transistors Q1 and Q2 are off, the first and second diodes D1 and D2 are cut off, while the third and fourth diodes D3 and D4 are on. At this point, the voltage across the two high-voltage MOS transistors can be considered the input voltage of the two windings. When both high-voltage MOS transistors are turned on simultaneously, due to Lenz's law, the winding with the higher input voltage generates a magnetic field, and the winding with the lower input voltage induces a reverse electromotive force (EMF), ultimately causing energy input from the high-voltage input winding to "reverse-flow" to the winding with the lower input voltage. When one high-voltage MOS transistor is turned off and the other is turned on, if the input voltage on the side with the turned-on high-voltage MOS transistor is higher than the side with the turned-off high-voltage MOS transistor, a reverse electromotive force equal to the higher input voltage will be induced on the winding with the turned-off high-voltage MOS transistor. Because the input voltage is lower than the induced reverse electromotive force, the high-voltage power supply will charge the low-voltage power supply. Since the two high-voltage MOS tubes are turned on at the same time or one is turned on and the other is turned off, the high input voltage will be fed back to the low input voltage. Therefore, a decoupling diode must be added between the primary winding and the high-voltage MOS tube to cut off the backfeed loop.

[0056] In the embodiment of the present invention, the voltage stress of the case with and without decoupling diodes is verified by simulation. When the decoupling diode is not added, at AC input 300V and DC input 800V, the DC side high voltage MOS tube will be subjected to a large voltage stress when the auxiliary switching power supply is started, such as Figure 5 After adding the decoupling diode, the voltage stress on the DC side MOS tube during startup is significantly reduced, as shown in Figure 6 shown. Figure 5 and Figure 6 The figure in the middle is a comparison of the voltage stress borne by the high-voltage tube under normal operation of the power supply, including the cases where both high-voltage MOS tubes are turned on, one is turned on, and both are turned off. Figure 5 The maximum voltage stress that the medium and high voltage MOS tube can withstand is above 2.4kV. Figure 6 It has dropped to about 1.7kV. Figure 5 、 6 The minimum voltage that the high-voltage MOS tube can withstand after the medium power supply is working stably. Figure 6 The voltage stress on the MOS tube in the circuit is 0V, while Figure 5 The voltage is 500V in the figure. This is because the reverse voltage stress is borne by the diode after adding the decoupling diode.

[0057] like Figure 2 As shown, in this embodiment, the feedback module includes an AC feedback module and a DC feedback module. The AC and DC feedback modules have the same circuit structure, both consisting of optocouplers (U1, U2), TL431 (U3, U5), and capacitor and resistor components. They are based on the TL431 type III compensator, which is commonly used in the design of flyback circuits. To ensure that the power supply has a good dynamic response, the feedback loops on the AC and DC sides have different parameter designs depending on the input voltage range. In specific implementations, the TL431 can also be replaced with the AZ431.

[0058] In this embodiment, the output rectifier and filter module consists of a fifth diode D5, a fourth capacitor C4, a fifth capacitor C5, and a seventh resistor R7. The fifth diode D5 is essential for flyback power supply filtering. The fourth and fifth capacitors C4 and C5 provide filtering and voltage stabilization. A dummy load R7 is used to stabilize the output voltage. The flyback power supply has current source characteristics and cannot operate in an open circuit.

[0059] like Figure 3 As shown, in this embodiment, the power management chip adopts NCP1380D. Figure 3 This is a circuit diagram of the AC-side power management chip and its peripheral circuits. The DC-side design is identical to the AC side. One end of the twenty-seventh resistor R27 is connected to the Aux1 terminal of the transformer's auxiliary winding S2, and the other end is connected to the anode of the eighteenth diode D18 and the twenty-eighth resistor R28. The eighteenth diode D18 and the twenty-eighth resistor R28 are connected in parallel, and then in series with the parallel combination of the thirteenth capacitor C13 and the twenty-ninth resistor R29 to form a zero-crossing detection circuit. The power management chip uses the zero-crossing point of the auxiliary winding voltage to determine the resonance start time, and then infer the valley position of the high-voltage MOS transistor's Vds resonant voltage, achieving valley capture and low-loss turn-on.

[0060] The sixth diode D6, the seventh diode D7, the sixteenth resistor R16, the thirteenth resistor R13, and the ninth and tenth capacitors C9 and C10 form the soft-start circuit for the power management chip. The anode of the sixth diode D6 is connected to the Aux1 terminal of the transformer's auxiliary winding S2, and one terminal of the thirteenth resistor R13 is connected to the AC voltage input. Before the power management chip starts, the ninth capacitor C9 is charged through the thirteenth resistor R13. When the capacitor reaches the power management chip's startup voltage, the power management chip begins oscillating. Subsequently, the voltage is charged through the auxiliary winding Aux1 to maintain the operating voltage level of the power management chip's VCC pin.

[0061] In this embodiment, the AC and DC auxiliary windings are coupled to a multi-primary transformer. The voltages of the two primary windings cross zero at the same time, thereby controlling the simultaneous switching of the first MOS transistor Q1 and the second MOS transistor Q2. The feedback pin FB of the power management chip U4 is connected to the feedback module; the current sense pin CS is connected to the source of the second MOS transistor Q2 via the third resistor R3, implementing overcurrent protection through this pin; the fault detection pin Fault is connected to the midpoint of the series connection of the 30th resistor R30 and the 31st resistor R31. The other end of the 30th resistor R30 is connected to the input voltage and current. This circuit detects the input voltage and implements overvoltage protection; the timing pin Ct is connected to the 14th capacitor C14, which is used to set the switching frequency of the flyback power supply in low-power operation; the power pin VCC is connected to the power soft-start module; and the drive pin DRV is connected to the MOS transistor driver module.

[0062] In this embodiment, if Figure 4 As shown, the MOS transistor driving module is composed of a ninth transistor Q9, a tenth transistor Q10, a thirty-second resistor R32, a thirty-third resistor R33 and a fifteenth capacitor C15. This is a commonly used push-pull structure. Using this circuit can increase the driving voltage and reduce the loss of the MOS transistor.

[0063] Figure 7 For Figure 2 The corresponding multi-transformer auxiliary switching power supply circuit schematic, where the AC input voltage source and the DC input voltage source are each connected to an independent transformer. The part in the red box is Figure 7 Relative to Figure 2 Extra devices. It can be seen that the use of Figure 2 The solution shown significantly reduces the number of components.

[0064] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0065] 1. Significantly Reduced System Cost: By integrating multiple traditional auxiliary switching power supplies into a single circuit structure, multiple transformers and their corresponding peripheral components, such as output rectification, filtering, and pre-load resistors, are eliminated. Compared to traditional discrete auxiliary power supply structures, this invention significantly reduces the number of components, effectively reducing material and manufacturing costs.

[0066] 2. Effectively Reduce Device Size and Optimize Spatial Layout: This invention utilizes a transformer structure with multiple inputs sharing a secondary winding, allowing previously dispersed auxiliary power sources to be integrated onto a single circuit board, significantly reducing the overall size of the auxiliary power module. This not only saves internal device space but also provides more possibilities for the rational arrangement of other key components, facilitating the miniaturization and compactness of new energy equipment.

[0067] 3. Improve overall system efficiency: By eliminating multiple rectification and filtering components on the secondary side of the transformer, the corresponding conduction loss and static power consumption are reduced. At the same time, the redundant loss caused by the parallel operation of multiple auxiliary power sources is avoided, thereby significantly improving the working efficiency and energy conversion rate of the auxiliary switching power supply.

[0068] In summary, the present invention provides a multi-channel adaptive input auxiliary switching power supply solution with reasonable structure and superior performance, which solves the key technical problems of high auxiliary source cost, low efficiency and large size in the prior art, and has good application prospects and promotion value.

[0069] The above is only a specific embodiment of the present invention and cannot be used to limit the scope of the present invention. Equal changes made by ordinary technicians in this technical field based on this creation, as well as changes well known to technicians in this field, should still fall within the scope of the present invention.

Claims

1. A multi-channel adaptive input auxiliary switching power supply, characterized in that: The auxiliary switching power supply includes a multi-primary transformer and N groups of input voltage sources; The multi-primary transformer has N primary windings and one secondary winding; the N groups of input voltage sources are respectively connected to corresponding primary windings, and each primary winding outputs a voltage signal through the secondary winding; Each set of input voltage sources is connected to a set of power management modules. The power input terminals of the power management modules are connected to the corresponding input voltage sources. The MOS transistor drive signals output by the power management modules are connected to the gates of the high-voltage MOS transistors via the MOS transistor drive modules. The drains of the high-voltage MOS transistors are connected to the primary winding via voltage stress absorption modules. The voltage stress absorption modules are used to reduce the voltage stress caused by the simultaneous input of AC and DC voltage sources into a single transformer. The output end of the secondary winding is connected to an output rectifier and filter module, and the output rectifier and filter module is used to rectify and filter the output voltage of the secondary side of the transformer; Each group of power management modules is connected to the output end of the rectification and filtering module through an independent feedback module.

2. The auxiliary switching power supply with multi-channel adaptive input according to claim 1, characterized in that: The power management module includes a power management chip, a zero-crossing detection circuit connected to the zero-crossing detection pin of the power management chip, and a soft-start circuit connected to the VCC power pin of the power management chip, and the soft-start circuit is connected to the input voltage source.

3. The auxiliary switching power supply with multi-channel adaptive input according to claim 2, characterized in that: The multi-primary transformer also includes N auxiliary windings, and the N primary windings have the same winding direction; the winding direction of the auxiliary winding and the secondary winding is opposite to that of the primary winding; the auxiliary winding is connected to the zero-crossing detection pin of the power management chip through the zero-crossing detection circuit, and is also connected to the VCC power pin of the power management chip through the soft start circuit.

4. The auxiliary switching power supply with multi-channel adaptive input according to claim 1, characterized in that: The voltage stress absorption module includes a decoupling diode, an anode of the decoupling diode is connected to the primary winding, and a cathode of the decoupling diode is connected to the drain of the high-voltage MOS tube.

5. The auxiliary switching power supply with multi-channel adaptive input according to claim 1, characterized in that: The feedback module includes a three-terminal voltage regulator and an optocoupler.

6. The auxiliary switching power supply with multi-channel adaptive input according to claim 1, characterized in that: The MOS tube driving module includes a push-pull circuit.

7. The auxiliary switching power supply with multi-channel adaptive input according to claim 1, characterized in that: The output rectification and filtering module includes a rectifier diode, an output filtering capacitor, and a load resistor.

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