A power supply system

Abstract

The application discloses a power supply system, which comprises at least one power supply module, wherein the first power supply module comprises a power receiving unit, a switch unit, an error amplification unit and a grounding unit; the input end of the power receiving unit is connected with the power input end as the input end of the first power supply module; the output end of the power receiving unit is connected with the input end of the switch unit; the output end of the switch unit is grounded through the grounding unit; the error amplification unit outputs the control voltage to the control end of the switch unit according to the voltage difference between the voltage of the voltage divider of the grounding unit and the voltage of the set first reference voltage source, so as to control the current passing through the switch unit; the voltage on the stable current passing through the power receiving unit is maintained, that is, the stability of the power supply system is maintained.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically, to a power supply system. Background Technology

[0002] In existing power supply systems, multiple power supply modules can be powered by converters. If the power receiving unit of a power supply module is affected by its operating state and environmental factors, and the load current changes significantly, it will affect the power supply current of the power supply system and lead to instability in the power supply of the entire system. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a power supply system that can maintain the current stability of the power supply module and ensure the normal operation of the power supply system.

[0004] This invention provides a power supply system, which includes at least one power supply module, wherein the first power supply module includes a power receiving unit, a switching unit, an error amplification unit, and a grounding unit;

[0005] The input terminal of the first power supply module is connected to the power input terminal of the power supply system, and the output terminal of the first power supply module is grounded.

[0006] The input terminal of the power receiving unit serves as the input terminal of the first power supply module, the output terminal of the power receiving unit is connected to the input terminal of the switching unit, the output terminal of the switching unit is connected to the first terminal of the grounding unit, and the second terminal of the grounding unit serves as the output terminal of the first power supply module.

[0007] The error amplification unit collects the voltage difference between the first terminal of the grounding unit and the first reference voltage source input to its first input terminal based on the voltage difference at the second input terminal, and outputs a control voltage to the control terminal of the switching unit to control the current passing through the switching unit.

[0008] Preferably, the power supply system further includes a feedback unit, a current acquisition unit, and an open-loop feedforward unit;

[0009] The input terminal of the first power supply module is connected to the power input terminal, specifically:

[0010] The input terminal of the first power supply module is connected to the power input terminal through the feedback unit;

[0011] The current acquisition unit is used to acquire the voltage drop across the feedback unit and output the acquired voltage drop to the open-loop feedforward unit;

[0012] The open-loop feedforward unit outputs a compensation current to the input terminal of the first power supply module based on the voltage drop output by the current acquisition unit and the voltage difference between the preset second reference voltage source.

[0013] As an improvement to the above solution, the first power supply module also includes an overcurrent protection unit;

[0014] The overcurrent protection unit outputs a control signal to the control terminal of the switching unit based on the voltage drop output by the current acquisition unit and the voltage difference between the preset third reference voltage source, thereby controlling whether the switching unit is turned on.

[0015] Preferably, the grounding unit includes a grounding resistor;

[0016] The switching unit includes an NMOS transistor;

[0017] The drain of the NMOS transistor serves as the input terminal of the switching unit, the source of the NMOS transistor serves as the output terminal of the switching unit, and the gate of the NMOS transistor serves as the control terminal of the switching unit.

[0018] As a preferred embodiment, the error amplification unit includes an error amplifier;

[0019] The non-inverting input of the error amplifier serves as the first input of the error amplification unit, the inverting input of the error amplifier serves as the second input of the error amplification unit, the output of the error amplifier serves as the output of the error amplification unit, and the output of the error amplification unit is connected to the control terminal of the switching unit.

[0020] Furthermore, the first power supply module also includes a first diode and a first resistor;

[0021] The output terminal of the error amplification unit is connected to the control terminal of the switching unit, specifically including:

[0022] The output terminal of the error amplification unit is connected to the control terminal of the switching unit through the first resistor;

[0023] The output terminal of the error amplification unit is connected to the cathode of the first diode, and the anode of the first diode is connected to the control terminal of the switching unit.

[0024] Preferably, the feedback unit includes a feedback resistor; the first end of the feedback resistor serves as the first end of the feedback unit and is connected to the power input terminal, and the second end of the feedback resistor serves as the second end of the feedback unit and is connected to the input terminal of the first power supply module.

[0025] The current acquisition unit includes a subtraction operational amplifier, a second resistor, a third resistor, a fourth resistor, and a fifth resistor;

[0026] The non-inverting input terminal of the subtraction operational amplifier is connected to the first terminal of the feedback unit through the second resistor, the inverting input terminal of the subtraction operational amplifier is connected to the second terminal of the feedback unit through the third resistor, the inverting input terminal of the subtraction operational amplifier is also grounded through the fourth resistor, the output terminal of the subtraction operational amplifier serves as the output terminal of the current acquisition unit, and the output terminal of the subtraction operational amplifier is also connected to its non-inverting input terminal through the fifth resistor.

[0027] Preferably, the open-loop feedforward unit includes an optocoupler, a second diode, and a sixth resistor;

[0028] The first end of the optocoupler serves as the input end of the open-loop feedforward unit and is connected to the output end of the current acquisition unit; the second end of the optocoupler is used to connect to the second reference voltage source; the third end of the optocoupler is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the on-voltage source of the optocoupler; the fourth end of the optocoupler is connected to the anode of the second diode; and the cathode of the second diode serves as the output end of the open-loop feedforward unit and is connected to the input end of the first power supply module.

[0029] Preferably, the overcurrent protection unit includes a comparator and a third diode;

[0030] The non-inverting input of the comparator is used to connect to the third reference voltage source, and the inverting input of the comparator serves as the input of the overcurrent protection unit and is connected to the output of the current acquisition unit.

[0031] The output terminal of the comparator is connected to the anode of the third diode, and the cathode of the third diode serves as the output terminal of the overcurrent protection unit, which is connected to the control terminal of the switching unit.

[0032] The present invention provides a power supply system that, by detecting the voltage of the grounding unit and controlling the conduction characteristics of the switching unit based on the voltage difference between the first reference voltage source of the set error amplification unit and the detected voltage, can maintain the voltage on the current passing through the power receiving unit, thereby maintaining the stability of the power supply system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of a power supply system according to another embodiment of the present invention;

[0035] Figure 3 This is a circuit diagram of a power supply system provided in another embodiment of the present invention;

[0036] Figure 4 This is a circuit schematic diagram of a current acquisition unit provided in an embodiment of the present invention;

[0037] Figure 5 This is a circuit schematic diagram of an open-loop feedforward unit provided in an embodiment of the present invention;

[0038] Figure 6 This is a circuit diagram of an overcurrent protection unit provided in an embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] See Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of the present invention. The power supply system includes a power supply module, namely the first power supply module.

[0042] The first power supply module includes a power receiving unit, a switching unit, an error amplification unit, and a grounding unit;

[0043] The input terminal of the first power supply module is connected to the power input terminal of the power supply system, which is used to input a constant power supply V. CC The output terminal of the first power supply module is grounded.

[0044] The input terminal of the power receiving unit serves as the input terminal of the power supply module. The output terminal of the power receiving unit is connected to the input terminal of the switching unit. The output terminal of the switching unit is connected to the first terminal of the grounding unit. The second terminal of the grounding unit serves as the output terminal of the first power supply module.

[0045] The second input terminal of the error amplifier unit is connected to the first terminal of the current-limiting power supply and is used to acquire the voltage at the first terminal of the grounding unit; the first input terminal of the error amplifier unit is used to input the first reference voltage source V. REF The output of the error amplification unit is connected to the control terminal of the switching unit.

[0046] When the voltage value at the first terminal of the grounding unit is too low, the error amplification unit compares the voltage values ​​of the input voltage at the first input terminal and the second input terminal, and outputs a control voltage to the switching unit according to the relationship between the magnitudes. This controls the current flowing through the input terminal to the output terminal of the switching unit to increase, the current flowing through the grounding unit to increase, and the voltage value at the first terminal of the grounding unit to rise, thus balancing the voltage on the receiving unit.

[0047] When the voltage at the first terminal of the grounding unit is too high, the error amplification unit compares the voltage values ​​of the input voltage at the first input terminal and the second input terminal, and outputs a control voltage to the switching unit according to the relationship between the magnitudes. This controls the current flowing through the input and output terminals of the switching unit to decrease, the current flowing through the grounding unit to decrease, and the voltage at the first terminal of the grounding unit to decrease, thus balancing the voltage on the receiving unit.

[0048] The voltage difference of the first reference voltage source of the error amplification unit is set according to the conduction characteristics of the switching unit, which can maintain the voltage on the grounding resistor, that is, keep the current through the power receiving unit constant, and ensure the stability of the power supply system.

[0049] It should be noted that, in other embodiments provided by the present invention, the power supply system further includes a second power supply unit, the input terminal of the second power supply module is also connected to the power input terminal of the power supply system, and the output terminal of the second power supply module is grounded;

[0050] Specifically, the structure of the second power supply module can be the same as that of the first power supply module, including a second power receiving unit, a second switching unit, a second error unit and a grounding unit. Its specific connection relationship and working principle are similar to those of the first power supply module, and will not be described in detail here.

[0051] The structure of the second power supply module may also include only the second power receiving unit. The input terminal of the second power receiving unit serves as the input terminal of the second power supply module, and the output terminal of the second power receiving unit serves as the output terminal of the second power supply module. Power is directly supplied to the second power receiving unit through the power input terminal.

[0052] Example 2

[0053] See Figure 2 The diagram shown is a structural schematic of a power supply system provided in another embodiment of the present invention. The power supply system further includes a feedback unit, a current acquisition unit, and an open-loop feedforward unit.

[0054] The input terminal of the first power supply module is connected to the power input terminal, specifically:

[0055] The power input terminal of the power supply system is connected to the first terminal of the feedback unit, and the second terminal of the feedback unit is connected to the input terminal of the first power supply module.

[0056] The first and second input terminals of the current acquisition unit are connected to the two ends of the feedback unit, respectively. The output terminal of the current acquisition unit is connected to the input terminal of the open-loop feedforward unit, and the output terminal of the open-loop feedforward unit is connected to the input terminal of the first power supply module.

[0057] The current acquisition unit acquires the voltage across the feedback unit and outputs the voltage drop across the feedback unit to the open-loop feedforward unit. The open-loop feedforward unit then calculates the voltage drop across the feedback unit and compares it with a preset second reference voltage source V. IMAX The comparison is performed, and the compensation current is output to the input terminal of the first power supply module.

[0058] When the current on the feedback unit decreases, the voltage drop on the feedback unit will decrease, and the voltage drop output to the open-loop feedforward unit will decrease. The open-loop feedforward unit compares the input voltage drop with the voltage value of the second reference voltage source and outputs a corresponding compensation current to the input terminal of the first power supply module, so that the current output to the first power supply module remains stable.

[0059] When the current on the feedback unit increases, the voltage drop on the feedback unit will increase, and the voltage drop output to the open-loop feedforward unit will increase. The open-loop feedforward unit compares the input voltage drop with the voltage value of the second reference voltage source and outputs a corresponding compensation current to the input terminal of the first power supply module, so that the current output to the first power supply module remains stable.

[0060] By detecting the voltage drop on the feedback unit, a compensation current is fed back to the first power supply module to ensure the stability of the power supply current of the power supply system.

[0061] Example 3

[0062] See Figure 2 The first power supply module also includes an overcurrent protection unit. The first input terminal of the overcurrent protection unit is connected to the output terminal of the current acquisition unit, and the second input terminal of the overcurrent protection unit is used to connect to the third reference voltage source V. IP The output terminal is connected to the control terminal of the switching unit;

[0063] The overcurrent protection unit compares the voltage drop across the feedback unit with a preset third reference voltage. When the voltage drop across the feedback unit exceeds the third reference voltage, the feedback unit is overloaded. At this time, the output control voltage controls the switch unit to turn off and stops supplying power to the first power supply module.

[0064] The overcurrent protection unit limits the current on the feedback unit, preventing the power supply system from overloading the feedback unit due to too many connected power supply modules.

[0065] Example 4

[0066] See Figure 3This is a circuit diagram of a power supply system provided in another embodiment of the present invention; the grounding unit of the first power supply module includes a grounding resistor R. RB1 ;

[0067] The switching unit includes an NMOS transistor N1;

[0068] The drain of NMOS transistor N1 is connected to the output of the power receiving unit as the input terminal of the switching unit, and the source of NMOS transistor N1 is connected to the grounding resistor R as the output terminal of the switching unit. RB1 The gate of NMOS transistor N1 is grounded and connected to the output of the error amplifier unit as the control terminal of the switching unit.

[0069] It should be noted that the grounding unit can also be a component with other impedance functions composed of multiple resistors, or a resistor and other components can be combined to form a device.

[0070] It should be noted that the switching unit can also be other switching transistors with switching functions, such as transistors or other field-effect transistors, and their specific connection relationship can be determined according to the characteristics of different switching transistors.

[0071] By detecting the grounding resistance, the current on the receiving unit is converted into voltage detection, which facilitates the control of the switching unit. The current between the drain and source is controlled by the NMOS transistor to balance the current of the receiving unit and maintain the stability of the circuit power supply.

[0072] Example 5

[0073] See Figure 3 The error amplification unit of the first power supply module includes an error amplifier U1;

[0074] The non-inverting input of error amplifier U1 serves as the first input of the error amplification unit, connected to the first reference voltage source V. REF The inverting input terminal of the error amplifier U1 is connected to the source of the NMOS transistor as the second input terminal UI of the error amplification unit, and is used to detect the grounding resistance R. FB1 The voltage on the circuit is such that the output terminal of the error amplifier U1 serves as the output terminal of the error amplification unit, and the output terminal of the error amplification unit is connected to the control terminal of the switching unit.

[0075] The grounding resistance R is detected based on the inverting input of the error amplifier. FB1 The voltage divider V on FB1 The first reference voltage source V input to its non-inverting input terminal REF The voltage difference, output control voltage V g The gate current of the NMOS transistor is controlled to adjust the grounding resistance R. FB1 The voltage divider V on FB1 .

[0076] The error amplifier can output a corresponding control voltage to the switching unit based on the voltage difference between the non-inverting and inverting input terminals, so as to control the current on the switching unit and correct the current on the first power supply module.

[0077] Example 6

[0078] See Figure 3 The first power supply module also includes a first diode D. O1 and the first resistor R O1 ;

[0079] The output of the error amplifier U1 in the error amplifier unit is connected to the first resistor R. O1 It is connected to the gate of NMOS transistor N1 in the switching unit;

[0080] First diode D O1 The anode of the diode is connected to the gate of the NMOS transistor N1 in the switching unit, and the first diode D... O1 The cathode is connected to the output terminal of the error amplifier U1 of the error amplification unit.

[0081] The first power supply module provided by this invention mainly functions through an error amplifier and an NMOS transistor, which can stabilize the current of the powered unit.

[0082] If the power supply system has multiple power supply modules, the error amplifier and NMOS transistor configured in each power supply module can balance the current of each power source. The parallel redundancy design of the power supply modules increases the overcurrent capacity of the power supply system.

[0083] Error amplifier U1 operates in the linear region, based on the first reference voltage source V input at the non-inverting input terminal. REF The voltage V input to the inverting input terminal FB1 The differential voltage difference, linear output control voltage V g The NMOS transistor is driven by a single power supply, VDD, and the error amplifier U1 is powered by a single power supply.

[0084] The first reference voltage source V input to the non-inverting input terminal of the error amplifier REF Based on the NMOS transistor drive voltage setting, when the voltage difference between the non-inverting and inverting input terminals is zero, the control voltage V... g This is the reference voltage value.

[0085] When an NMOS transistor operates in the saturation region, the drain-source voltage Vs in the saturation region is... DS When constant, the drain-source current I DS With gate-source voltage V GS Increase and increase. Through the source of the NMOS transistor, a grounding resistor R... FB1- Grounding, the current regulation process of the first power supply module is as follows:

[0086] When the first power supply module provides stable power, and the current flowing through the power receiving unit decreases, the V detected at the inverting input of the error amplifier... FB1 Decrease, leading to V REF- V FB1 Increase, error amplification output control voltage V g It also increases, causing the NMOS transistor source-gate voltage V to rise. gs The increase leads to an increase in the source-drain current I of the NMOS transistor. ds Increase, grounding resistance R FB1 As the current in the receiving unit increases, the current in the grounding resistance R also increases. FB1 Voltage V on FB1 Increase the current to maintain a stable current in the receiving unit.

[0087] Therefore, the power of this power supply system satisfies the following formula, and the constant current value I output by the power supply system is... REF This setting can be achieved by adjusting the grounding resistance of the power supply module, that is:

[0088] Among them, R FB1 R FB2 This refers to the resistance value of the grounding resistor for several power supply modules.

[0089] First resistor R O1 This is the gate drive resistor for the NMOS transistor. It is typically a small value and depends on the NMOS transistor's specifications. The first diode is D. O1 Provides a turn-off circuit for the NOMS tube.

[0090] The voltage difference detected by the error amplification unit controls the current of the switching unit, maintaining a stable current in the power supply module and improving the stability of the power supply system.

[0091] Example 7

[0092] See Figure 3 The feedback unit includes a feedback resistor R. BAT ;

[0093] Feedback resistor R BAT The first terminal serves as the first terminal of the feedback unit and is connected to the power input terminal Vcc, with feedback resistor R. BAT The second end serves as the second end of the feedback unit and is connected to the input end of the first power supply module;

[0094] See Figure 4 This is a circuit diagram of a current acquisition unit provided in an embodiment of the present invention. The current acquisition unit includes a subtraction operational amplifier U3 and a second resistor R. B+Third resistor R B- Fourth resistor R B-’ and the fifth resistor R B+’ ;

[0095] The non-inverting input of the subtraction operational amplifier U3 is connected to the second resistor R. B+ Connected to the first terminal of the feedback unit, used to detect the feedback resistance R of the feedback unit. BAT The voltage V at the first terminal B+ The inverting input of the subtraction operational amplifier U3 is connected to the third resistor R. B- Connected to the second terminal of the feedback unit, used to detect the feedback resistance R of the feedback unit. BAT The voltage V at the second terminal B- The inverting input of the subtraction operational amplifier U3 is also connected to a fourth resistor R. B-’ Grounded, the output of the subtraction operational amplifier U3 is used as the output of the current acquisition unit, and the voltage drop V across the output feedback resistor is... IBAT The output of the subtraction operational amplifier U3 is also connected to the input of the open-loop feedforward unit via a fifth resistor R. B+’ Connect it to its positive input terminal.

[0096] The current acquisition unit is used to detect the feedback resistor R. BAT The voltage difference across the two ends is sampled using a low-resistance precision resistor and processed by a subtraction circuit.

[0097]

[0098] Let R B+ =kR B- , Then V IBAT =I BAT (numerical value);

[0099] The voltage across the feedback resistor is detected by the non-inverting and inverting inputs of the subtraction operational amplifier, and the voltage drop corresponding to the voltage difference across the feedback resistor is output by the subtraction operational amplifier to the open-loop feedforward unit.

[0100] Example 8

[0101] See Figure 5 This is a circuit schematic diagram of an open-loop feedforward unit provided in an embodiment of the present invention; the open-loop feedforward unit includes an optocoupler CP and a second diode D. CP and the sixth resistor R CPS ;

[0102] The first terminal of the optocoupler CP serves as the input terminal of the open-loop feedforward unit, connected to the output terminal of the current acquisition unit, and is used to receive the voltage drop V detected by the current acquisition unit. IBATThe second terminal of the optocoupler CP is used to connect to the second reference voltage source V. IMAX The third terminal of the optocoupler CP is connected to the sixth resistor R. CPS The first terminal is connected to the sixth resistor R. CPS The second terminal is connected to the on-voltage source V of the optocoupler CP. CP Connection: The fourth terminal of the optocoupler CP is connected to the second diode D. CP The anode connection of the second diode D is described. CP The cathode serves as the output of the open-loop feedforward unit and is connected to the input of the first power supply module.

[0103] When the closed-loop regulation of the power circuit of the power supply system is abnormal or the dynamic load change of the power supply module is too large, it can be adjusted by the open-loop feedforward module or the current compensation can be performed on the downstream module.

[0104] The actual current value output from the power supply input is detected by measuring the voltage drop across the feedback resistor and compared with the set current value. An open-loop feedforward module is constructed using an optocoupler. The detected voltage drop V... IBAT With the set second reference voltage source V IMAX The voltage values ​​are compared, when the voltage drop V IBAT More than V IMAX The time triggers the LED in the optocoupler to conduct and emit light, forming a primary current I. CPP The current is compensated for and then sent to the first power supply module.

[0105] Assume the forward voltage of the LED in the optocoupler is V. CP The equivalent resistance is R CPP The transmission ratio of an optocoupler, i.e., the ratio of the primary to the secondary current when current is generated, is 1 / R. CPP .

[0106] Then V IMAX The current constant current setting is represented as follows:

[0107]

[0108] According to the set value V REF The value changes in real time. Specifically, when multiple power supply modules exist, the grounding resistance of the second power supply module is R. FB2 The current compensation process is as follows:

[0109] Assuming that during the closed-loop regulation of the constant current circuit, the constant current output by the power supply system is I REF Become I REF +ΔI, after the subtraction operational amplifier U3 of the current acquisition unit samples and calculates the ratio, the voltage value is the output voltage drop V. IBAT The value becomes I REF+ΔI, in the primary circuit of the optocoupler, a primary current ΔI / R is formed due to the voltage difference. CPP Therefore, the current transfer ratio is 1 / R CPP The optocoupler forms a compensation current I in the secondary circuit. CP =ΔI, so that the feedback resistor R BAT Current I on BAT Restore to I REF .

[0110] The power supply circuit is compensated by a current acquisition unit and an open-loop feedforward unit to maintain the stability of the power supply current of the entire power supply system.

[0111] Example 9

[0112] See Figure 6 This is a circuit diagram of an overcurrent protection unit provided in an embodiment of the present invention; the overcurrent protection unit includes a comparator U4 and a third diode D. IP ;

[0113] The non-inverting input of comparator U4 is used to connect to the third reference voltage source V. IP The inverting input of comparator U4 serves as the input of the overcurrent protection unit and is connected to the output of the current acquisition unit to input the voltage drop V to be acquired. IBAT ;

[0114] The output of comparator U4 is connected to the third diode D. IP The anode connection is made, and comparator U4 is connected by V. DD Power supply, third diode D IP The cathode serves as the output terminal of the overcurrent protection unit, connected to the control terminal of the switching unit, for outputting the control signal V. G The NMOS transistor controlling the switching unit.

[0115] The overcurrent protection unit uses a third reference voltage source V IP Set safety threshold V IP When the feedback resistor R BAT The voltage drop on it exceeds V IP At that time, a low-level control signal V is output through comparator U4. G Pulling down the NMOS transistor's drive terminal level forces the NMOS transistor to shut down, stopping the first power supply module from operating and ensuring the power supply safety of the first power supply module.

[0116] It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered to be within the scope of protection of this invention.

Claims

1. A power supply system, characterized in that, The power supply system includes at least one power supply module, wherein the first power supply module includes a power receiving unit, a switching unit, an error amplification unit, and a grounding unit; The input terminal of the first power supply module is connected to the power input terminal of the power supply system, and the output terminal of the first power supply module is grounded. The input terminal of the power receiving unit serves as the input terminal of the first power supply module, the output terminal of the power receiving unit is connected to the input terminal of the switching unit, the output terminal of the switching unit is connected to the first terminal of the grounding unit, and the second terminal of the grounding unit serves as the output terminal of the first power supply module. The error amplification unit collects the voltage difference between the first terminal of the grounding unit and the first reference voltage source input to its first input terminal based on the voltage difference at the second input terminal, and outputs a control voltage to the control terminal of the switching unit to control the current passing through the switching unit; The power supply system also includes a feedback unit, a current acquisition unit, and an open-loop feedforward unit; The input terminal of the first power supply module is connected to the power input terminal, specifically: The input terminal of the first power supply module is connected to the power input terminal through the feedback unit; The current acquisition unit is used to acquire the voltage drop across the feedback unit and output the acquired voltage drop to the open-loop feedforward unit; The open-loop feedforward unit outputs a compensation current to the input terminal of the first power supply module based on the voltage drop output by the current acquisition unit and the voltage difference between the preset second reference voltage source.

2. The power supply system according to claim 1, characterized in that, The first power supply module also includes an overcurrent protection unit; The overcurrent protection unit outputs a control signal to the control terminal of the switching unit based on the voltage drop output by the current acquisition unit and the voltage difference between the preset third reference voltage source, thereby controlling whether the switching unit is turned on.

3. The power supply system according to claim 1, characterized in that, The grounding unit includes a grounding resistor; The switching unit includes an NMOS transistor; The drain of the NMOS transistor serves as the input terminal of the switching unit, the source of the NMOS transistor serves as the output terminal of the switching unit, and the gate of the NMOS transistor serves as the control terminal of the switching unit.

4. The power supply system according to claim 1, characterized in that, The error amplification unit includes an error amplifier; The non-inverting input of the error amplifier serves as the first input of the error amplification unit, the inverting input of the error amplifier serves as the second input of the error amplification unit, the output of the error amplifier serves as the output of the error amplification unit, and the output of the error amplification unit is connected to the control terminal of the switching unit.

5. The power supply system according to claim 4, characterized in that, The first power supply module also includes a first diode and a first resistor; The output terminal of the error amplification unit is connected to the control terminal of the switching unit, specifically including: The output terminal of the error amplification unit is connected to the control terminal of the switching unit through the first resistor; The output terminal of the error amplification unit is connected to the cathode of the first diode, and the anode of the first diode is connected to the control terminal of the switching unit.

6. The power supply system according to claim 1, characterized in that, The feedback unit includes a feedback resistor; the first end of the feedback resistor serves as the first end of the feedback unit and is connected to the power input terminal, and the second end of the feedback resistor serves as the second end of the feedback unit and is connected to the input terminal of the first power supply module. The current acquisition unit includes a subtraction operational amplifier, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; The non-inverting input terminal of the subtraction operational amplifier is connected to the first terminal of the feedback unit through the second resistor, the inverting input terminal of the subtraction operational amplifier is connected to the second terminal of the feedback unit through the third resistor, the inverting input terminal of the subtraction operational amplifier is also grounded through the fourth resistor, the output terminal of the subtraction operational amplifier serves as the output terminal of the current acquisition unit, and the output terminal of the subtraction operational amplifier is also connected to its non-inverting input terminal through the fifth resistor.

7. The power supply system according to claim 1, characterized in that, The open-loop feedforward unit includes an optocoupler, a second diode, and a sixth resistor; The first end of the optocoupler serves as the input end of the open-loop feedforward unit and is connected to the output end of the current acquisition unit; the second end of the optocoupler is used to connect to the second reference voltage source; the third end of the optocoupler is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the on-voltage source of the optocoupler; the fourth end of the optocoupler is connected to the anode of the second diode; and the cathode of the second diode serves as the output end of the open-loop feedforward unit and is connected to the input end of the first power supply module.

8. The power supply system according to claim 2, characterized in that, The overcurrent protection unit includes a comparator and a third diode; The non-inverting input of the comparator is used to connect to the third reference voltage source, and the inverting input of the comparator serves as the input of the overcurrent protection unit and is connected to the output of the current acquisition unit. The output terminal of the comparator is connected to the anode of the third diode, and the cathode of the third diode serves as the output terminal of the overcurrent protection unit, which is connected to the control terminal of the switching unit.

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