Current sharing module and power supply system

Abstract

The present application discloses a current sharing module and a power supply system, which module includes a current amplification circuit, a current sharing bus voltage control circuit, a voltage output circuit and an output voltage adjustment circuit; the current amplification circuit is used to output a first voltage; the current sharing bus voltage control circuit is used to sample the second voltage of the current sharing bus, obtain a third voltage used to characterize the magnitude of the current sharing bus voltage, and update the second voltage when the first voltage is greater than the third voltage; the voltage output circuit is used to judge the magnitude of the first voltage and the second voltage in real time, and output a fourth voltage; the output voltage adjustment circuit is used to adjust the output voltage of one of N switching power supplies based on the fourth voltage, thereby solving the problems of poor dynamic regulation, poor anti-interference ability and low steady-state voltage accuracy of the power supply system in the existing solution, and further solving the problem of inability to share current and poor steady-state voltage accuracy caused by high output voltage in an environment with large external interference.

Description

Technical Field

[0001] The present application relates to the technical field of switching power supplies, and in particular to current sharing during redundant switching power supplies, and more specifically to a current sharing module and a power supply system. Background Art

[0002] With the rapid development of power electronics technology, switching power supplies are being used more and more widely, especially high-power, high-power-density, and high-reliability switching power supplies. A single switching power supply has now developed to over a kilowatt, but the power required in large industrial equipment or trains such as industry and railways has reached several kilowatts or even tens of kilowatts. Therefore, a power supply system consisting of multiple switching power supplies in parallel is required to meet the power supply requirements.

[0003] At the same time, in order to improve the reliability of the equipment, the power supply of the equipment needs to adopt an "N+1" redundant power supply system, where N is an integer greater than or equal to 1. In the event of a single switching power supply failure, it can be cut out without affecting the normal operation of the system.

[0004] However, for most switching power supplies, due to deviations in output voltage and wire impedance, current sharing cannot be achieved, causing one switching power supply to be overloaded and causing the switching power supply to fail. Therefore, most switching power supplies do not support direct parallel use.

[0005] Currently, the most widely used load current sharing solution is the maximum current sharing method. This method samples the output current of a switching power supply, follows the maximum current, and adjusts the output voltage, so that the output current of the remaining parallel switching power supplies follows the current of the switching power supply with the largest output current, achieving automatic current sharing. Currently, common control solutions on the market include TI's UCX907 and UCCX9002 series chips. However, this control solution has the following shortcomings:

[0006] (1) During the dynamic regulation process, current sharing cannot be achieved;

[0007] (2) When the switching power supply with the largest output current enters a serious overload state, it is easy to trigger the switching power supply overload protection and cause the power supply system to work abnormally;

[0008] (3) The high price of this chip will increase the material cost of the power supply system. Summary of the Invention

[0009] The main purpose of this application is to provide a current balancing module and a power supply system, which not only has good dynamic adjustment but also can reduce costs, so as to solve the problem of poor dynamic adjustment of the power supply system in the existing solution.

[0010] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a current balancing module is provided, wherein N current balancing modules are applied to a power supply system composed of N switching power supplies, and the N current balancing modules correspond one-to-one to the N switching power supplies, and the output ends of the N switching power supplies are connected in parallel directly or through auxiliary devices, and each current balancing module includes a current amplification circuit, a current balancing bus voltage control circuit, a voltage output circuit and an output voltage adjustment circuit; the current amplification circuit has a first input end, a second input end and an output end, the first input end of the current amplification circuit is electrically connected to the sampling positive end of one of the N switching power supplies, and the second input end of the current amplification circuit is electrically connected to the sampling positive end of one of the N switching power supplies. The sampling negative terminal of the current amplifier circuit is electrically connected, the current amplifier circuit is used to sample a voltage signal representing the output current size of one of the switching power supplies, and amplify the voltage signal representing the output current size of one of the N switching power supplies and output a first voltage; the current sharing bus voltage control circuit has a first input terminal, a second input terminal and an output terminal, the first input terminal of the current sharing bus voltage control circuit is electrically connected to the output terminal of the current amplifier circuit, the second input terminal of the current sharing bus voltage control circuit is electrically connected to the output terminal of the current sharing bus voltage control circuit, the current sharing bus voltage control circuit is used to sample the second voltage of the current sharing bus, obtain a third voltage used to represent the size of the current sharing bus voltage, and output the The first voltage is compared with the third voltage, and when the first voltage is greater than the third voltage, the second voltage is updated; the voltage output circuit has a first input end, a second input end and an output end, the first input end of the voltage output circuit is electrically connected to the first input end of the current sharing bus voltage control circuit, the second input end of the voltage output circuit is electrically connected to the current sharing bus of one of the N switching power supplies, and the second input end of the voltage output circuit is electrically connected to the output end of the current sharing bus voltage control circuit, the voltage output circuit is used to judge the size of the first voltage and the second voltage in real time, and output a fourth voltage, the fourth voltage is used to represent the difference between the first voltage and the second The judgment result of the voltage magnitude; the output voltage adjustment circuit has a first input end, a second input end, a first output end, and a second output end, the first input end of the output voltage adjustment circuit is electrically connected to the output end of the voltage output circuit, the second input end of the output voltage adjustment circuit is electrically connected to the second input end of the current-sharing bus voltage control circuit, the first output end of the output voltage adjustment circuit is electrically connected to the remote compensation positive end of one of the N switching power supplies, the second output end of the output voltage adjustment circuit is electrically connected to the remote compensation negative end of one of the N switching power supplies, and the output voltage adjustment circuit is used to adjust the output voltage of one of the N switching power supplies according to the fourth voltage.

[0011] Furthermore, the current amplification circuit includes a first resistor module, a second resistor module, a third resistor module, a fourth resistor module and a first operational amplifier; the first end of the first resistor module is respectively electrically connected to the sampling positive end of one of the N switching power supplies, the second end of the first resistor module, the first end of the third resistor module and the non-inverting input end of the first operational amplifier, and the first end of the second resistor module is respectively electrically connected to the sampling negative end of one of the N switching power supplies, the second end of the second resistor module, the first end of the fourth resistor module and the inverting input end of the first operational amplifier; the output end of the first operational amplifier, the second end of the fourth resistor module, the first input end of the voltage output circuit and the first input end of the current sharing bus voltage control circuit are electrically connected; the second end of the third resistor module is electrically connected to the second output end of the output voltage adjustment circuit.

[0012] Furthermore, the current-sharing bus voltage control circuit includes a fifth resistor module, a sixth resistor module, a first capacitor module, a first field-effect transistor and a second operational amplifier; the non-inverting input terminal of the second operational amplifier is electrically connected to the drain of the first field-effect transistor, the first input terminal of the voltage output circuit and the output terminal of the current amplification circuit, respectively; the first end of the fifth resistor module is electrically connected to the first end of the sixth resistor module, the first end of the first capacitor module, the first input terminal of the voltage output circuit, the output terminal of the current amplification circuit and the second input terminal of the voltage output circuit, respectively; the second end of the fifth resistor module is electrically connected to the inverting input terminal of the second operational amplifier, the output terminal of the second operational amplifier is electrically connected to the gate of the first field-effect transistor, the source of the first field-effect transistor is electrically connected to the second end of the sixth resistor module, and the second end of the first capacitor module is electrically connected to the second output terminal of the output voltage adjustment circuit and the remote compensation negative terminal of one of the N switching power supplies.

[0013] Furthermore, the voltage output circuit includes a seventh resistor module, an eighth resistor module, a ninth resistor module, a second capacitor module, a third capacitor module and a third operational amplifier; the first end of the seventh resistor module is electrically connected to the output end of the current amplification circuit and the first input end of the current-sharing bus voltage control circuit, respectively; the second end of the seventh resistor module is electrically connected to the first end of the seventh resistor module, the inverting input end of the third operational amplifier and the first end of the ninth resistor module, respectively; the first end of the eighth resistor module is electrically connected to the current-sharing bus of one of the N switching power supplies, the non-inverting input end of the third operational amplifier, the second input end of the current-sharing bus voltage control circuit and the output end of the current-sharing bus voltage control circuit, respectively; the second end of the ninth resistor module is electrically connected to the first end of the third capacitor module, the second end of the third capacitor module, the output end of the third operational amplifier, the first end of the second capacitor module and the input end of the output voltage adjustment circuit, the second end of the second capacitor module is electrically connected to the second output end of the output voltage adjustment circuit, and the inverting input end of the third operational amplifier is electrically connected to the second end of the eighth resistor module.

[0014] Furthermore, the output voltage adjustment circuit includes a tenth resistor module, an eleventh resistor module, a transistor, a second field-effect transistor and a fourth operational amplifier; the non-inverting input terminal of the fourth operational amplifier is electrically connected to the output terminal of the voltage output circuit and the drain of the second field-effect transistor respectively; the output terminal of the fourth operational amplifier is electrically connected to the base of the transistor, the collector of the transistor is electrically connected to the remote compensation positive terminal of one of the N switching power supplies, the emitter of the transistor is electrically connected to the inverting input terminal of the fourth operational amplifier, the first end of the tenth resistor module and the first end of the eleventh resistor module respectively, the second end of the tenth resistor module is electrically connected to the remote compensation negative terminal of one of the N switching power supplies, the second end of the eleventh resistor module is electrically connected to the current source, the source of the second field-effect transistor is grounded, and the gate of the second field-effect transistor is electrically connected to the second output terminal of the current-sharing bus voltage control circuit.

[0015] Furthermore, the current-sharing bus voltage control circuit is also used to: when the difference between the first voltage and the third voltage is less than or equal to a first set value, control the second voltage to be updated to a second set value; when the difference between the first voltage and the third voltage is greater than the first set value, control the second voltage to be updated to a third set value.

[0016] Furthermore, N is an integer greater than or equal to 1.

[0017] According to another aspect of the present application, a power supply system is also provided, comprising N switching power supplies, wherein the output ends of the N switching power supplies are connected in parallel directly or through auxiliary devices, and the power supply system further comprises M current balancing modules of any one of the above-mentioned types; the first input end of the current amplification circuit of each current balancing module is electrically connected to the output voltage sampling positive end of one of the switching power supplies, the second input end of the current amplification circuit of each current balancing module is electrically connected to the output voltage sampling negative end of one of the switching power supplies, the first output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the remote compensation positive end of one of the switching power supplies, the second output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the remote compensation negative end of one of the switching power supplies, and the second input end of the voltage output circuit of each current balancing module is electrically connected together.

[0018] Furthermore, the power supply system also includes a fourth capacitor module, the second input end of the voltage output circuit of each current balancing module is electrically connected to the first end of the fourth capacitor module, and the second output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the second end of the fourth capacitor module.

[0019] Furthermore, N is an integer greater than or equal to 1, M is an integer greater than or equal to 1 and less than or equal to N, and M is equal to N.

[0020] Applying the technical solution of the present application, each current sharing module outputs a first voltage, a second voltage, a third voltage, a fourth voltage, a fifth voltage, a sixth voltage, and a seventh voltage respectively. According to the fourth voltage (the fourth voltage is used to characterize the judgment result of the magnitude of the first voltage and the second voltage), the output voltage of one of the N switching power supplies is adjusted. The output voltage adjustment circuit is used to adjust the output voltage of the switching power supply according to the fourth voltage, and compare the fourth voltage with the reference voltage Vref. When the fourth voltage is less than or equal to the reference voltage Vref, the value of the sixth voltage is the reference voltage Vref, the seventh voltage is a low level, and the output voltage of the switching power supply is adjusted. The output voltage is an internally set value for this switching power supply. When the fourth voltage is greater than the second set voltage, the sixth voltage is equal to the fifth voltage, and the seventh voltage is a high-level output voltage increase. In the case of large external environmental interference, the interference signal is coupled to the current sharing circuit, causing the output of the switching power supply to increase. When the voltage reaches the preset output voltage upper limit of the switching power supply, the voltage drop can no longer be fine-tuned for current sharing, resulting in uneven current sharing of the switching power supply. The switching power supply has high steady-state output voltage accuracy, which can prevent the switching power supply with the largest output current from triggering overcurrent protection and the output voltage from exceeding the set specifications, thereby solving the problem of poor current sharing caused by high output voltage fluctuations in an environment with large external interference and the problem of poor steady-state voltage accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0022] Figure 1 shows a principle block diagram of a current sharing module according to an embodiment of the present application;

[0023] Figure 2 The following is a schematic circuit diagram of a current sharing module according to an embodiment of the present application;

[0024] Figure 3 A functional block diagram of a power supply system of a current sharing module according to an embodiment of the present application is shown.

[0025] The above drawings include the following reference numerals:

[0026] 100. Current amplification circuit; 200. Current-sharing bus voltage control circuit; 300. Voltage output circuit; 400. Output voltage adjustment circuit. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in 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. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element or intervening elements may be present. Moreover, in the specification and claims, when it is described that an element is "connected to" another element, the element may be "directly connected to" the other element or "connected to" the other element through a third element.

[0031] As introduced in the background technology, for most switching power supplies, due to the deviation of output voltage and wire impedance, it will lead to the inability to achieve current balancing, causing a switching power supply to be in an overload state, resulting in failure of the switching power supply. Therefore, most switching power supplies do not support direct parallel use. In order to solve the problem of poor dynamic regulation of the power supply system in the existing solution, the embodiment of the present application provides a current balancing module and a power supply system.

[0032] like Figure 1 and Figure 2As shown, a current balancing module, N of the current balancing modules are applied to a power supply system composed of N switching power supplies, and the N current balancing modules correspond to the N switching power supplies one by one, the output terminals of the N switching power supplies are connected in parallel directly or through auxiliary devices, the above N is an integer greater than or equal to 1, each of the above current balancing modules includes a current amplification circuit 100, a current balancing bus voltage control circuit 200, a voltage output circuit 300, an output voltage adjustment circuit 400, Vcs+ and a sampling negative terminal Vcs- of one of the N switching power supplies, and the N switching power supplies. The current amplifier circuit 100 includes a current sharing bus LS of one of the N switching power supplies, a remote compensation positive terminal +Sense and a remote compensation negative terminal -Sense of one of the N switching power supplies; the current amplifier circuit 100 has a first input terminal, a second input terminal and an output terminal, the first input terminal of the current amplifier circuit 100 is electrically connected to the Vcs+ of one of the N switching power supplies, the second input terminal of the current amplifier circuit 100 is electrically connected to the sampling negative terminal Vcs- of one of the N switching power supplies, and the first input terminal and the second input terminal of the current amplifier circuit 100 are used to communicate with the N One of the above-mentioned switching power supplies is electrically connected, and the above-mentioned current amplification circuit 100 is used to sample a voltage signal representing the output current of one of the above-mentioned switching power supplies, and amplify the voltage signal used to represent the output current of one of the N above-mentioned switching power supplies and output a first voltage V1 (each current sharing module has a first voltage V1); the current sharing bus voltage control circuit 200 has a first input end, a second input end and an output end, the first input end of the above-mentioned current sharing bus voltage control circuit 200 is electrically connected to the output end of the above-mentioned current amplification circuit 100, and the second input end of the above-mentioned current sharing bus voltage control circuit 200 is electrically connected to the output end of the above-mentioned current sharing bus voltage control circuit 200, and the above-mentioned current sharing bus voltage control circuit 200 is used to sample the second voltage V2 of the above-mentioned current sharing bus (each current sharing module has a second voltage V2), obtain a third voltage V3 used to represent the magnitude of the above-mentioned current sharing bus voltage (each current sharing module has a third voltage V3), and compare the above-mentioned first voltage V1 with the above-mentioned third voltage V3. When the above-mentioned first voltage V1 is greater than the above-mentioned third voltage V3, the above-mentioned second voltage V2 is updated;The voltage output circuit 300 has a first input terminal, a second input terminal and an output terminal. The first input terminal of the voltage output circuit 300 is electrically connected to the first input terminal of the current-sharing bus voltage control circuit 200, and the second input terminal of the voltage output circuit 300 is electrically connected to the current-sharing bus LS of one of the N switching power supplies. The second input terminal of the voltage output circuit 300 is electrically connected to the output terminal of the current-sharing bus voltage control circuit 200. The voltage output circuit 300 is used to judge the size of the first voltage V1 and the second voltage V2 in real time, and output a fourth voltage V4 (each current-sharing module has a fourth voltage V4). The fourth voltage V4 is used to represent the judgment result of the size of the first voltage V1 and the second voltage V2; the output voltage adjustment circuit 400 has a first input terminal, a second input terminal, a first output terminal and a second output terminal. The first input terminal of the output voltage adjustment circuit 400 is electrically connected to the output terminal of the voltage output circuit 300, and the second input terminal of the output voltage adjustment circuit 400 is electrically connected to the second input terminal of the current-sharing bus voltage control circuit 200. The first output terminal of the voltage adjustment circuit 400 is electrically connected to the remote compensation positive terminal +Sense of one of the N switching power supplies, and the second output terminal of the output voltage adjustment circuit 400 is electrically connected to the remote compensation negative terminal -Sense of one of the N switching power supplies. The output voltage adjustment circuit 400 is configured to adjust the output voltage of one of the N switching power supplies based on the fourth voltage V4. The output voltage adjustment circuit 400 is configured to adjust the output voltage of the switching power supply based on the fourth voltage V4. The fourth voltage V4 is compared with a reference voltage Vref. When the fourth voltage V4 is less than or equal to the reference voltage Vref, the sixth voltage V6 is equal to the reference voltage Vref, the seventh voltage V7 is at a low level, and the output voltage of the switching power supply is an internally set value of the switching power supply. When the fourth voltage V4 is greater than the second set voltage, the sixth voltage V6 (each current balancing module has a sixth voltage V6) is equal to the fifth voltage V5 (each current balancing module has a fifth voltage V5), and the seventh voltage V7 (each current balancing module has a seventh voltage V7) is at a high level, and the output voltage is adjusted upward.

[0033] The above-mentioned current-sharing bus voltage control circuit is also used to perform the following steps: when the difference between the above-mentioned first voltage V1 and the above-mentioned third voltage V3 is less than or equal to the first set value, the above-mentioned second voltage V2 is controlled to be updated to the second set value; when the difference between the above-mentioned first voltage V1 and the above-mentioned third voltage V3 is greater than the above-mentioned first set value, the above-mentioned second voltage V2 is controlled to be updated to the third set value.

[0034] The output current of each switching power supply in the power supply system is sampled, and the voltage representing the magnitude of the output current of each switching power supply (i.e., the first voltage V1) is compared with the voltage representing the magnitude of the current sharing bus voltage (i.e., the third voltage V3). When the first voltage V1 is less than the third voltage V3, the corresponding switching power supply is fine-tuned to increase its output voltage. When the first voltage V1 is greater than the third voltage V3 and the difference between the first voltage V1 and the third voltage V3 is less than or equal to the first set value, the current sharing bus voltage (i.e., the second voltage V2) is updated to the second set value to achieve current equalization in the power supply system during steady state. When the first voltage V1 is greater than the third voltage V3 but the difference between the first voltage V1 and the third voltage V3 is greater than the first set value, the output voltage of the remaining switching power supplies is fine-tuned to increase, and the output voltage of these switching power supplies is set to the fourth set value, so that the current sharing bus voltage is updated to the third set value. This achieves the purpose of adjusting the dynamic regulation performance of the power supply system, and reduces current overshoot, thereby preventing the switching power supply with the largest output current from triggering the overcurrent protection of the power supply system, and simultaneously achieving high output voltage accuracy of the system.

[0035] The present application is based on the fourth voltage V4 (the fourth voltage V4 is used to represent the result of determining the magnitude of the first voltage V1 and the second voltage V2) to adjust the output voltage of one of the N switching power supplies. The output voltage adjustment circuit 400 is used to adjust the output voltage of the switching power supply based on the fourth voltage V4. The fourth voltage V4 is compared with a reference voltage Vref. When the fourth voltage V4 is less than or equal to the reference voltage Vref, the sixth voltage V6 is equal to the reference voltage Vref, and the seventh voltage V7 is at a low level. The output voltage of the switching power supply is an internally set value of the switching power supply. When the fourth voltage V4 is greater than the second set voltage, the sixth voltage V6 is equal to the fifth voltage V5, and the seventh voltage V7 is at a high level. The output voltage is then increased. In the presence of significant external interference, the interference signal couples to the current sharing circuit, causing the output of the switching power supply to increase. When the voltage reaches the preset output voltage upper limit of the switching power supply, the voltage drop can no longer be fine-tuned for current sharing, resulting in uneven current sharing of the switching power supply. This solves the problem of current sharing failure caused by high output voltage fluctuations and poor steady-state voltage accuracy in environments with significant external interference.

[0036] The present application is described in detail below in conjunction with the embodiments and the accompanying drawings to help those skilled in the art better understand the inventive concept of the present application. However, the scope of protection of the claims of the present application is not limited to the following embodiments. For those skilled in the art, all other embodiments obtained without creative work without departing from the inventive concept of the present application shall fall within the scope of protection of the present application.

[0037] See also Figure 1 and Figure 2As shown, the composition and connection relationship of each unit circuit are as follows:

[0038] The current amplifier circuit 100 includes a first resistor module R1, a second resistor module R2, a third resistor module R3, a fourth resistor module R4 and a first operational amplifier U1A; the first end of the first resistor module R1 is electrically connected to the sampling positive terminal Vcs+ of one of the N switching power supplies, the second end of the first resistor module R1, the first end of the third resistor module R3 and the non-inverting input terminal of the first operational amplifier U1A, the first end of the second resistor module R2 is electrically connected to the sampling negative terminal Vcs- of one of the N switching power supplies, the second end of the second resistor module R2 , the first end of the above-mentioned fourth resistance module R4 is electrically connected to the inverting input end of the above-mentioned first operational amplifier U1A; the output end of the above-mentioned first operational amplifier U1A, the second end of the above-mentioned fourth resistance module R4, the first input end of the above-mentioned voltage output circuit 300 and the first input end of the above-mentioned current-sharing bus voltage control circuit 200 are electrically connected (the output end of the above-mentioned first operational amplifier U1A and the second end of the above-mentioned fourth resistance module R4 are electrically connected together as the output end of the current amplification circuit 100); the second end of the above-mentioned third resistance module R3 is electrically connected to the second output end of the above-mentioned output voltage adjustment circuit 400.

[0039] like Figure 1 and Figure 2As shown, the above-mentioned current-sharing bus voltage control circuit 200 includes a fifth resistor module R5, a sixth resistor module R6, a first capacitor module C1, a first field-effect transistor Q1 and a second operational amplifier U1B; the non-inverting input terminal of the above-mentioned second operational amplifier U1B is electrically connected to the drain of the above-mentioned first field-effect transistor Q1, the first input terminal of the above-mentioned voltage output circuit and the output terminal of the above-mentioned current amplifier circuit (the non-inverting input terminal of the above-mentioned second operational amplifier U1B and the drain of the above-mentioned first field-effect transistor Q1 are electrically connected together as the first input terminal of the current-sharing bus voltage control circuit 200), the first end of the above-mentioned fifth resistor module R5 is electrically connected to the first end of the above-mentioned sixth resistor module R6, the first end of the above-mentioned first capacitor module C1, the first input terminal of the above-mentioned voltage output circuit, the above-mentioned current amplifier circuit The output end of the voltage output circuit is electrically connected to the second input end of the voltage output circuit (the first end of the fifth resistor module R5 is electrically connected to the first end of the sixth resistor module R6 and the first end of the first capacitor module C1 as the output end of the current-sharing bus voltage control circuit 200), the second end of the fifth resistor module R5 is electrically connected to the inverting input end of the second operational amplifier U1B, the output end of the second operational amplifier U1B is electrically connected to the gate of the first field-effect transistor Q1, the source of the first field-effect transistor Q1 is electrically connected to the second end of the sixth resistor module R6, and the second end of the first capacitor module C1 is electrically connected to the second output end of the output voltage adjustment circuit and the remote compensation negative end -Sense of one of the N switching power supplies.

[0040] like Figure 1 and Figure 2As shown, the voltage output circuit 300 includes a seventh resistor module R7, an eighth resistor module R8, a ninth resistor module R9, a second capacitor module C2, a third capacitor module C3 and a third operational amplifier U2A; the first end of the seventh resistor module R7 is electrically connected to the output end of the current amplification circuit 100 and the first input end of the current-sharing bus voltage control circuit 200 (the first end of the seventh resistor module R7 is the first input end of the voltage output circuit 300), the second end of the seventh resistor module R7 is electrically connected to the first end of the seventh resistor module R7, the inverting input end of the third operational amplifier U2A and the first end of the ninth resistor module R9, the first end of the eighth resistor module R8 is electrically connected to the current-sharing bus LS of one of the N switching power supplies, the non-inverting input end of the third operational amplifier U2A, the second input end of the current-sharing bus voltage control circuit 200 and the current-sharing bus voltage The output end of the control circuit 200 is electrically connected (the first end of the eighth resistor module R8 is the second input end of the voltage output circuit 300), the second end of the above-mentioned ninth resistor module R9 is electrically connected to the first end of the above-mentioned third capacitor module C3, the second end of the above-mentioned third capacitor module C3, the output end of the above-mentioned third operational amplifier U2A, the first end of the above-mentioned second capacitor module C2 and the input end of the above-mentioned output voltage adjustment circuit 400 (the second end of the above-mentioned ninth resistor module R9 is electrically connected to the first end of the above-mentioned third capacitor module C3, the second end of the above-mentioned third capacitor module C3, the output end of the above-mentioned third operational amplifier U2A and the first end of the above-mentioned second capacitor module C2 as the output end of the voltage output circuit 300), the second end of the above-mentioned second capacitor module C2 is electrically connected to the second output end of the above-mentioned output voltage adjustment circuit, and the inverting input end of the above-mentioned third operational amplifier U2A is electrically connected to the second end of the above-mentioned eighth resistor module R8.

[0041] like Figure 1 and Figure 2As shown, the output voltage adjustment circuit 400 includes the output voltage adjustment circuit including a tenth resistor module R10, an eleventh resistor module R11, a transistor Q2, a second field effect transistor Q3 and a fourth operational amplifier U2B; the non-inverting input terminal of the fourth operational amplifier U2B is electrically connected to the output terminal of the voltage output circuit 300 and the drain of the second field effect transistor Q3 respectively (the non-inverting input terminal of the fourth operational amplifier U2B is the first input terminal of the output voltage adjustment circuit 400); the output terminal of the fourth operational amplifier U2B is electrically connected to the base of the transistor Q2, and the collector of the transistor Q2 is electrically connected to the remote compensation positive terminal +Sense of one of the N switching power supplies (the collector of the transistor Q2 is the first output terminal of the output voltage adjustment circuit 400 ), the emitter of the transistor Q2 is electrically connected to the inverting input terminal of the fourth operational amplifier U2B, the first end of the tenth resistor module R10, and the first end of the eleventh resistor module R11, respectively; the second end of the tenth resistor module R10 is electrically connected to the remote compensation negative terminal -Sense of one of the N switching power supplies (the second end of the tenth resistor module R10 is the second output terminal of the output voltage adjustment circuit 400); the second end of the eleventh resistor module R11 is electrically connected to the current source Vcc; the source of the second field-effect transistor Q3 is grounded; and the gate of the second field-effect transistor Q3 is electrically connected to the second output terminal of the current-sharing bus voltage control circuit 200 (the gate of the second field-effect transistor Q3 serves as the second input terminal of the output voltage adjustment circuit 400).

[0042] like Figure 3 As shown, the power supply system includes 4 switching power supplies and 4 current balancing circuits of the present application, and the connection relationship is: the first input end of the current amplification circuit of each of the above-mentioned current balancing modules is electrically connected to the output voltage sampling positive terminal Vcs+ of the above-mentioned switching power supplies, the second input end of the current amplification circuit of each of the above-mentioned current balancing modules is electrically connected to the output voltage sampling negative terminal Vcs- of the above-mentioned switching power supplies, the first output end of the output voltage adjustment circuit of each of the above-mentioned current balancing modules is electrically connected to the remote compensation positive terminal +Sense of the above-mentioned switching power supplies, the second output end of the output voltage adjustment circuit of each of the above-mentioned current balancing modules is electrically connected to the remote compensation negative terminal -Sense of the above-mentioned switching power supplies, and the second input end of the voltage output circuit of each of the above-mentioned current balancing modules (i.e., the current balancing bus LS) is electrically connected together.

[0043] In addition, if Figure 1 and Figure 3As shown, because the second input terminal of the voltage output circuit 300 is electrically connected to the current sharing bus LS of one of the N switching power supplies, a capacitor C5A / C5B / C5C / C5D is electrically connected between the second input terminal of the voltage output circuit 300 of each current sharing module and the remote compensation negative terminal -Sense of a switching power supply, so as to filter out interference of the switching power supply on the current sharing bus connection LS.

[0044] Combine Figure 1 、 Figure 2 and Figure 3 The working principle of this application is analyzed as follows:

[0045] (1) When the output current of each switching power supply is evenly distributed, the first voltage V1 of the voltage signal of each current sharing module and the second voltage V2 of the current sharing bus are equal;

[0046] The output current of each switching power supply is converted into a voltage signal Vcs representing the magnitude of the corresponding switching power supply output current through sampling resistors RS1A, RS1B, RS1C, and RS1D. The current amplification circuit 100, which is composed of the first resistor module R1, the second resistor module R2, the third resistor module R3, the fourth resistor module R4, and the first operational amplifier U1A, is a differential amplifier circuit that amplifies the voltage signal Vcs and outputs a first voltage V1. The amplification factor is the resistance value of the fourth resistor module R4 divided by the resistance value of the second resistor module R2. Therefore, the first voltage signal V1 can also represent the magnitude of the output current of each switching power supply.

[0047] After the second voltage V2 of the current-sharing bus undergoes impedance matching through the fifth resistor module R5, a third voltage V3 representing the magnitude of the current-sharing bus voltage is obtained. Since the value of the fifth resistor module R5 is very small, the voltage drop across it is negligible, and therefore the second voltage V2 and the third voltage V3 can be considered equal.

[0048] Because the first voltage V1 of each current-sharing module and the second voltage V2 of the current-sharing bus are equal in this state, the first voltage V1 and the third voltage V3 are also equal. Therefore, the second operational amplifier U1B outputs the fifth voltage V5 as a low level, the first field-effect transistor Q1 is not turned on, and the second voltage V2 of the current-sharing bus remains unchanged.

[0049] Since the first voltage V1 is equal to the second voltage V2 of the current-sharing bus, by reasonably setting the resistance values ​​of the seventh resistor module R7, the eighth resistor module R8, the ninth resistor module R9, the capacitance of the second capacitor module C2, and the capacitance of the third capacitor module C3 (the ninth resistor module R9 and the third capacitor module C3 form a proportional integral to amplify and accumulate errors, and the second capacitor module C2 mainly functions as a filter), and because the second field-effect transistor Q3 is not conducting, the fourth voltage V4 output by the third operational amplifier U2A can remain unchanged.

[0050] The fourth voltage V4 is converted into a current signal through the fourth operational amplifier U2B and the transistor Q2 and output to the remote compensation positive terminal +Sense. Since the output voltage of the fourth operational amplifier U2B follows the voltage of its positive input terminal, that is, the fourth voltage V4, the value of the converted current signal is the fourth voltage V4 divided by the resistance value of the tenth resistor module R10. The current signal value remains unchanged, so it will not control each switching power supply to adjust its output voltage, so that the output current of each switching power supply remains unchanged, so that the output of each switching power supply maintains a current-sharing state.

[0051] The fourth voltage V4 and the eleventh resistor modules R11 and R10 are converted into a current signal via the fourth operational amplifier U2B and transistor Q2, which is output to the remote sense positive terminal +Sense. When the fourth voltage V4 is greater than the reference voltage Vref, the seventh voltage V7 output by the fourth operational amplifier U2B follows the fourth voltage V4 at the non-inverting input terminal of the fourth operational amplifier U2B, and the value of the sixth voltage V6 is updated to the value of the fourth voltage V4. Therefore, the value of the converted current signal is V4 minus the reference voltage Vref divided by the resistance value of resistor R10, and the current signal value remains unchanged. When the fourth voltage V4 is less than or equal to the reference voltage Vref, transistor Q2 is reversely blocked, and the current signal value is 0. Therefore, the output voltage of each switching power supply is not adjusted, and the output current of each switching power supply remains unchanged, so that the output of each switching power supply maintains a current-sharing state. When the fourth voltage V4 is less than or equal to the reference voltage Vref, the output voltage of each switching power supply is the internally set voltage of each switching power supply.

[0052] Since the first field effect tube Q1 itself is turned on or only the body diode is turned on, the first voltage V1 and the second voltage V2 of the current sharing bus are associated in different ways. Therefore, when the output current of each switching power supply is unevenly distributed, according to whether the difference between the first voltage V1 of the first current sharing module and the second voltage V2 of the current sharing bus is greater than or equal to the first set value of the first field effect tube Q1, the following two cases are discussed. Figure 2 In the specific circuit, the first set value is the voltage drop across the body diode of the first field effect transistor Q1:

[0053] (2) When the output currents of the switching power supplies are unevenly distributed, it is assumed that the output current of the first current balancing module is higher than the output currents of the other current balancing modules, and the difference between the first voltage V1 of the first current balancing module and the second voltage V2 of the current balancing bus is less than or equal to the first set value;

[0054] In this state, the first voltage V1 of the first current sharing module is greater than the second voltage V2 of the current sharing bus, and the first voltage V1 of the voltage signal of the other current sharing modules is less than the second voltage V2 of the current sharing bus. The difference between this state and the first state is that:

[0055] The first voltage V1 of the first current balancing module is greater than the second voltage V2 of the current balancing bus, and thus the first voltage V1 of the first current balancing module is greater than its third voltage V3. Therefore, the operational amplifier U1B of the first current balancing module outputs a high level, and the first field effect transistor Q1 of the first current balancing module is turned on, and the second field effect transistor Q3 of the first current balancing module is turned on.

[0056] The first voltage V1 of the remaining current sharing modules is lower than the second voltage V2 of the current sharing bus, and thus the first voltage V1 of the remaining current sharing modules is lower than the third voltage V3 thereof. Therefore, the operational amplifier U1B of the remaining current sharing modules outputs a low level, and the first field effect transistors Q1 and the second field effect transistors Q3 of the remaining current sharing modules are both off.

[0057] In this state, the difference between the first voltage V1 of the remaining current balancing modules and the second voltage V2 of the current balancing bus must be less than the first set value, that is, less than the voltage drop across the body diode of the first field effect transistor Q1. Therefore, the body diodes of the first field effect transistors Q1 of the remaining current balancing modules are also not conducting.

[0058] Because the difference between the first voltage V1 of the first current balancing module and the second voltage V2 of the current balancing bus is less than or equal to the first set value, the second voltage V2 of the current balancing bus will be updated, and the updated voltage value is recorded as the second set value. Since the second input end of the voltage output circuit of each of the above-mentioned current balancing modules (i.e., the current balancing bus LS) is electrically connected together, the first field effect transistor Q1 of the first current balancing module is turned on, and the first field effect transistors Q1 themselves and their body diodes of the remaining current balancing modules are not turned on. Therefore, ignoring the voltage drop across the first field effect transistor Q1 of the first current balancing module and the sixth resistor module R6, it can be considered that the second set value is equal to the first voltage V1 of the current balancing module corresponding to the switching power supply with the largest output current;

[0059] Since the second field effect transistor Q3 of the first current balancing module is turned on, the voltage signal at the output end of the third operational amplifier U2A of the first current balancing module is pulled down to 0V, and the fourth voltage V4 of the first current balancing module is inevitably less than or equal to the reference voltage Vref. The transistor Q2 is reversely cut off, and the current signal output to its remote compensation positive terminal +Sense is 0. The output voltage of the switching power supply corresponding to the first current balancing module is controlled to be the corresponding switching power supply voltage setting value;

[0060] Because the first voltage V1 of the corresponding current-sharing module of the remaining switching power supplies is less than the updated value of the second voltage V2 of the current-sharing bus, the fourth voltage V4 at the output terminal of the third operational amplifier U2A in each corresponding current-sharing module increases. V4, along with R11 and R10, converts the voltage signal V4 into a current signal through the fourth operational amplifier U2B and transistor Q2, outputting it to the remote compensation positive terminal +Sense. When the fourth voltage V4 is greater than the reference voltage Vref, the seventh voltage V7 output by the fourth operational amplifier U2B follows the fourth voltage V4 at the non-inverting input terminal of the fourth operational amplifier U2B, and the value of the sixth voltage V6 is updated to the value of the fourth voltage V4. Therefore, the value of the converted current signal is V4 minus the reference voltage Vref divided by the resistance value of the tenth resistor module R10. The current signal value increases as the fourth voltage V4 increases, controlling the corresponding switching power supply to adjust its output voltage, causing the output voltage of the corresponding switching power supply to increase, thereby increasing the output current of the remaining switching power supplies.

[0061] Since the first voltage V1 of the first current balancing module is approximately equal to the updated second voltage V2 of the current balancing bus, the fourth voltage V4 at the output end of the third operational amplifier U2A of the first current balancing module remains unchanged. The fourth voltage V4 of the first current balancing module is converted into a current signal through the fourth operational amplifier U2B and the transistor Q2 inside the first current balancing module and output to its remote compensation positive terminal +Sense. Since the output voltage of the fourth operational amplifier U2B of the first current balancing module follows the voltage of its positive input terminal, that is, the fourth voltage V4 of the first current balancing module, the value of the converted current signal is the fourth voltage V4 divided by the resistance value of the tenth resistor module R10. The current signal value remains unchanged and will not control the switching power supply corresponding to the first current balancing module to adjust its output voltage;

[0062] For the remaining switching power supplies, since the first voltage V1 of the corresponding current sharing module is less than the updated value of the second voltage V2 of the current sharing bus, the fourth voltage V4 at the output terminal of the third operational amplifier U2A in each corresponding current sharing module increases. These fourth voltages V4 are converted into corresponding current signals through the corresponding fourth operational amplifier U2B and the corresponding transistor Q2 and output to the corresponding remote compensation positive terminal +Sense. The value of each current signal increases with the increase of the corresponding fourth voltage V4, and the corresponding power supply is controlled to adjust its output voltage, so that the output voltage of the corresponding switching power supply increases, and the output current of the remaining switching power supplies increases;

[0063] Through the above analysis, it can be seen that in this state, each current balancing module of the present invention realizes the equal distribution of the output current of each switching power supply in the power supply system;

[0064] (3) When the output currents of the switching power supplies are unevenly distributed, it is still assumed that the output current of the first current balancing module is higher than the output current of the other current balancing modules, but the difference between the first voltage V1 of the first current balancing module and the second voltage V2 of the current balancing bus is greater than the first set value.

[0065] The difference between this state and the second state is that, since the difference between the first voltage V1 of the voltage signal of the first current balancing module and the second voltage V2 of the current balancing bus is greater than the first set value, the updated value of the second voltage V2 of the current balancing bus is different, and the updated value of the second voltage V2 of the current balancing bus is recorded as the third set value. Since the difference between the first voltage V1 of the voltage signal and the second voltage V2 of the current balancing bus must be greater than the voltage drop value of the first field effect tube Q1 body diode in the remaining current balancing modules, the corresponding first field effect tube Q1 body diode of the current balancing module is turned on, and the sixth resistor of the first current balancing module is turned on. The voltage drop across module R6 cannot be ignored, so the third set value is a value between the first voltage V1 of the current sharing module corresponding to the switching power supply with the largest output current and the current value of the second voltage V2 of the current sharing bus. Since the current value of the second voltage V2 of the current sharing bus is related to the output current of the remaining switching power supplies, the third set value is related to the output current of the remaining switching power supplies. The body diode refers to the field effect tube. Due to the presence of free electrons and holes in the substrate, there will be a source-to-drain diode after the field effect tube is produced. This diode is generally called a body diode or a parasitic diode.

[0066] In this case, the first voltage V1 of the first current balancing module is greater than the updated value of the second voltage V2 of the current balancing bus. It can be inferred that the first current balancing module will control the corresponding switching power supply to adjust its output voltage, so that the output voltage of the switching power supply decreases and the current increases; the first voltage V1 of the remaining current balancing modules is less than the updated value of the second voltage V2 of the current balancing bus. It can be inferred that the remaining current balancing modules will control the corresponding switching power supply to adjust its output voltage, so that the output voltage of the switching power supply increases and the current decreases, thereby realizing the equal distribution of the output current of each switching power supply in the power supply system.

[0067] When the output currents of multiple current balancing modules in the power supply system are inconsistent with the output currents of the remaining current balancing modules, or when the output currents of the current balancing modules are different, the working principles are similar, and those skilled in the art can infer them, so they will not be described in detail. Through the above working principle analysis, it can be seen that the power supply system including the current balancing module of the present invention can dynamically adjust the output current of each switching power supply, so that the overshoot of the output current of each switching power supply is small, thereby avoiding the switching power supply with the largest output current triggering the overcurrent protection.

[0068] against Figure 3 The power supply system shown in the figure tests the current sharing and current sharing accuracy of the four switching power supplies under different loads. The results are shown in Table 1:

[0069] Table 1 Switching power supply table

[0070]

[0071] As shown in Table 1, it can be seen that in this embodiment, conventional operational amplifiers can be used to achieve current sharing of the output currents of each switching power supply, meeting high current sharing accuracy and high voltage accuracy.

[0072] It should be noted that the optimal solution for the power supply system of this application is that the number of current balancing modules is the same as the number of switching power supplies. Based on cost considerations, reducing the number of current balancing modules can also be implemented, but it will affect the implementation effect of this application.

[0073] The present application is not limited to the above-mentioned specific implementation methods. Based on the above content, in accordance with the common technical knowledge and customary means in this field, without departing from the above-mentioned basic technical ideas of the present application, the present application can also make other various forms of equivalent modifications, replacements or changes, all of which fall within the scope of protection of the present application.

[0074] It should be noted that the above electrical connection can be a direct electrical connection or an indirect electrical connection. Direct electrical connection means that two devices are directly connected, and indirect electrical connection means that other devices such as capacitors and resistors are connected between the connected A and B.

[0075] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0076] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0077] The current sharing module of the present application, when the voltage (i.e., the first voltage V1) used to characterize the output current of each switching power supply in a certain switching power supply in the power supply system is greater than the third voltage V3 used to characterize the voltage of the current sharing bus, the corresponding switching power supply is fine-tuned so that its output voltage increases. When the first voltage V1 is greater than the third voltage V3 and the difference between the above-mentioned first voltage V1 and the above-mentioned third voltage V3 is greater than the first set value, the output voltage of this switching power supply is set to the fourth set value, and the output voltages of the remaining switching power supplies increase. During the dynamic adjustment process of the power supply system, the output current overshoot of each switching power supply is small, thereby avoiding the switching power supply with the largest output current triggering overcurrent protection; when the first voltage V1 is greater than the third voltage V3 and the difference between the above-mentioned first voltage V1 and the above-mentioned third voltage V3 is greater than the first set value When the value is greater than the first set value, the output voltage of the remaining switching power supplies is fine-tuned to increase. The output voltage of this switching power supply is set to the fourth set value, which will cause the output voltage of the switching power supply to increase and the output voltage accuracy to fail to meet the specifications. When the first voltage V1 is greater than the third voltage V3 and the difference between the first voltage V1 and the third voltage V3 is less than or equal to the first set value, under the condition of large external environmental interference, the interference signal is coupled to the current sharing circuit, causing the output of the switching power supply to increase. When the voltage reaches the preset output voltage upper limit of the switching power supply, the voltage drop can no longer be fine-tuned for current sharing, resulting in uneven current distribution of the switching power supply, thereby solving the problem of poor current sharing caused by high output voltage in an environment with large external interference and the problem of poor steady-state voltage accuracy.

[0078] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A current balancing module, wherein N current balancing modules are applied to a power supply system composed of N switching power supplies, and the N current balancing modules correspond one-to-one to the N switching power supplies, and the output ends of the N switching power supplies are connected in parallel directly or through auxiliary devices, characterized in that: Each of the current sharing modules includes: a current amplifying circuit having a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the current amplifying circuit is electrically connected to a sampling positive terminal of one of the N switching power supplies, and the second input terminal of the current amplifying circuit is electrically connected to a sampling negative terminal of one of the N switching power supplies. The current amplifying circuit is configured to sample a voltage signal representing the magnitude of an output current of one of the N switching power supplies, and amplify the voltage signal representing the magnitude of the output current of one of the N switching power supplies to output a first voltage; A current-sharing bus voltage control circuit having a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the current-sharing bus voltage control circuit is electrically connected to the output terminal of the current amplification circuit, and the second input terminal of the current-sharing bus voltage control circuit is electrically connected to the output terminal of the current-sharing bus voltage control circuit, wherein the current-sharing bus voltage control circuit is configured to sample the second voltage of the current-sharing bus, obtain a third voltage used to characterize the magnitude of the current-sharing bus voltage, compare the first voltage with the third voltage, and update the second voltage when the first voltage is greater than the third voltage; a voltage output circuit having a first input end, a second input end, and an output end, wherein the first input end of the voltage output circuit is electrically connected to the first input end of the current-sharing bus voltage control circuit, the second input end of the voltage output circuit is electrically connected to the current-sharing bus of one of the N switching power supplies, and the second input end of the voltage output circuit is electrically connected to the output end of the current-sharing bus voltage control circuit, the voltage output circuit being configured to determine in real time the magnitudes of the first voltage and the second voltage and output a fourth voltage, the fourth voltage being configured to represent the determination result of the magnitudes of the first voltage and the second voltage; an output voltage adjustment circuit having a first input terminal, a second input terminal, a first output terminal, and a second output terminal, wherein the first input terminal of the output voltage adjustment circuit is electrically connected to the output terminal of the voltage output circuit, the second input terminal of the output voltage adjustment circuit is electrically connected to the second input terminal of the current-sharing bus voltage control circuit, the first output terminal of the output voltage adjustment circuit is electrically connected to the positive terminal of the remote compensation of one of the N switching power supplies, and the second output terminal of the output voltage adjustment circuit is electrically connected to the negative terminal of the remote compensation of one of the N switching power supplies, and the output voltage adjustment circuit is configured to adjust the output voltage of one of the N switching power supplies based on the fourth voltage; The output voltage adjustment circuit includes a switching device, the source of the switching device is grounded, the gate of the switching device is electrically connected to the second output end of the current-sharing bus voltage control circuit, and the drain of the switching device is electrically connected to the output end of the voltage output circuit.

2. The current balancing module according to claim 1, characterized in that: The current amplification circuit includes a first resistor module, a second resistor module, a third resistor module, a fourth resistor module and a first operational amplifier; the first end of the first resistor module is electrically connected to the sampling positive end of one of the N switching power supplies; the second end of the first resistor module, the first end of the third resistor module and the non-inverting input end of the first operational amplifier are electrically connected, and the first end of the second resistor module is electrically connected to the sampling negative end of one of the N switching power supplies; the second end of the second resistor module, the first end of the fourth resistor module and the inverting input end of the first operational amplifier are electrically connected; the output end of the first operational amplifier, the second end of the fourth resistor module, the first input end of the voltage output circuit and the first input end of the current sharing bus voltage control circuit are electrically connected; the second end of the third resistor module is electrically connected to the second output end of the output voltage adjustment circuit.

3. The current balancing module according to claim 1, characterized in that: The current-sharing bus voltage control circuit includes a fifth resistor module, a sixth resistor module, a first capacitor module, a first field-effect transistor and a second operational amplifier; the non-inverting input terminal of the second operational amplifier is electrically connected to the drain of the first field-effect transistor, the first input terminal of the voltage output circuit and the output terminal of the current amplification circuit, respectively; the first end of the fifth resistor module is electrically connected to the first end of the sixth resistor module, the first end of the first capacitor module and the second input terminal of the voltage output circuit, respectively; the second end of the fifth resistor module is electrically connected to the inverting input terminal of the second operational amplifier, the output terminal of the second operational amplifier is electrically connected to the gate of the first field-effect transistor, the source of the first field-effect transistor is electrically connected to the second end of the sixth resistor module, and the second end of the first capacitor module is electrically connected to the second output terminal of the output voltage adjustment circuit and the remote compensation negative terminal of one of the N switching power supplies.

4. The current balancing module according to claim 1, characterized in that: The voltage output circuit includes a seventh resistor module, an eighth resistor module, a ninth resistor module, a second capacitor module, a third capacitor module and a third operational amplifier; the first end of the seventh resistor module is electrically connected to the output end of the current amplification circuit and the first input end of the current sharing bus voltage control circuit, respectively; the second end of the seventh resistor module is electrically connected to the inverting input end of the third operational amplifier and the first end of the ninth resistor module, respectively; the first end of the eighth resistor module is electrically connected to the current sharing bus of one of the N switching power supplies, the second input end of the current sharing bus voltage control circuit and the output end of the current sharing bus voltage control circuit, the second end of the eighth resistor module is electrically connected to the non-inverting input end of the third operational amplifier, the second end of the ninth resistor module is electrically connected to the first end of the third capacitor module, the second end of the third capacitor module, the output end of the third operational amplifier, the first end of the second capacitor module and the input end of the output voltage adjustment circuit, and the second end of the second capacitor module is electrically connected to the second output end of the output voltage adjustment circuit.

5. The current balancing module according to claim 1, characterized in that: The output voltage adjustment circuit includes a tenth resistor module, an eleventh resistor module, a transistor and a fourth operational amplifier, the switching device is a second field-effect transistor; the non-inverting input terminal of the fourth operational amplifier is electrically connected to the output terminal of the voltage output circuit and the drain of the second field-effect transistor respectively; the output terminal of the fourth operational amplifier is electrically connected to the base of the transistor, the collector of the transistor is electrically connected to the remote compensation positive terminal of one of the N switching power supplies, the emitter of the transistor is electrically connected to the inverting input terminal of the fourth operational amplifier, the first end of the tenth resistor module and the first end of the eleventh resistor module respectively, the second end of the tenth resistor module is electrically connected to the remote compensation negative terminal of one of the N switching power supplies, the second end of the eleventh resistor module is electrically connected to the current source, the source of the second field-effect transistor is grounded, and the gate of the second field-effect transistor is electrically connected to the second output terminal of the current-sharing bus voltage control circuit.

6. The current balancing module according to any one of claims 1 to 5, characterized in that: The current sharing bus voltage control circuit is further used for: When the difference between the first voltage and the third voltage is less than or equal to a first set value, controlling the second voltage to be updated to a second set value; When the difference between the first voltage and the third voltage is greater than the first set value, the second voltage is controlled to be updated to the third set value.

7. The current balancing module according to any one of claims 1 to 5, characterized in that: The N is an integer greater than or equal to 2.

8. A power supply system comprising N switching power supplies, wherein the output terminals of the N switching power supplies are connected in parallel directly or through auxiliary devices, wherein: The power supply system further includes M current sharing modules according to any one of claims 1 to 7; The first input end of the current amplifying circuit of each current balancing module is electrically connected to the positive output voltage sampling end of one of the switching power supplies, the second input end of the current amplifying circuit of each current balancing module is electrically connected to the negative output voltage sampling end of one of the switching power supplies, the first output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the positive remote compensation end of one of the switching power supplies, the second output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the negative remote compensation end of one of the switching power supplies, and the second input end of the voltage output circuit of each current balancing module is electrically connected together.

9. The power supply system according to claim 8, characterized in that: The power supply system also includes a fourth capacitor module, the second input end of the voltage output circuit of each current balancing module is electrically connected to the first end of the fourth capacitor module, and the second output end of the output voltage adjustment circuit of each current balancing module is electrically connected to the second end of the fourth capacitor module.

10. The power supply system according to claim 8 or 9, characterized in that: The N is an integer greater than or equal to 2, the M is an integer greater than or equal to 2 and less than or equal to the N, and the M is equal to the N.

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