DC contactor driving power supply based on super capacitor transient support

Abstract

The invention discloses a DC contactor driving power supply based on super capacitor transient support, a Buck-Boost circuit is adopted to stably output rated coil power supply voltage, a constant current output function is introduced through a current sampling circuit and a current loop of a double-closed-loop structure, constant current and constant voltage charging of a super capacitor is realized, compared with a resistor current limiting mode, the charging mode is more flexible, and the charging efficiency is improved. The circuit has a fast charging function, can reduce heating loss, and is small in size and low in cost; the super capacitor string performs constant current-constant voltage charging through the Buck-Boost circuit, and the control system controls the driving switch to supply power to the contactor coil. When the contactor acts, the control system controls the driving switch to be turned on, the high-density electric quantity stored in the super capacitor string is released, instantaneous large current is provided for the contactor coil, reliable action of the contactor is ensured, the contactor keeps that the electric quantity is provided by the Buck-Boost circuit after action, and the input power supply cost and the occupied volume are reduced.

Description

Technical Field

[0001] This invention relates to the field of DC contactor drive technology, and more specifically to a DC contactor drive power supply based on supercapacitor transient support. Background Technology

[0002] As a type of switching electrical device, DC contactors have been widely used in many fields due to their unique performance and advantages. In the new energy field, electric vehicles, charging piles, and solar energy systems all rely on the precise control of DC contactors; in industrial equipment, many key components such as power systems and energy storage systems depend on their stable operation; in the rail transit field, the electrical systems of high-speed transportation vehicles such as high-speed rail and subways also widely use DC contactors; in addition, DC contactors play an indispensable role in special equipment such as aerospace and medical equipment.

[0003] In many high-voltage, high-current applications, to ensure that DC contactors can reliably interrupt current while reducing coil holding power consumption and minimizing system temperature rise, they are typically designed with dual-coil power supply. This dual-coil power supply method has unique characteristics: when the contactor actuates, the coil requires a large instantaneous (tens of milliseconds) starting current, which can range from several amperes to tens of amperes depending on the current rating of the contactor's main contacts and the coil supply voltage. However, once the contactor enters the holding state, its holding current is only 10% to 20% of the starting current.

[0004] Currently, there are two common power supply solutions for the coils of such DC contactors: one is to directly power them with a switching power supply, and the other is to step down the voltage with a transformer and then rectify it before power supply. Both of these power supply methods have some problems that urgently need to be solved in practical applications. When the coil starting current is large, a high-power switching power supply or a high-power transformer is often required to meet this instantaneous current demand. However, after the contactor enters the steady-state holding phase, its current demand is very small, resulting in extremely low power supply utilization, typically only 10% to 20%. Furthermore, the situation becomes even more complex when multiple contactors need to operate simultaneously. To meet the current demand when multiple contactors start simultaneously, multiple high-power switching power supplies or further increases in transformer power may be necessary. This not only significantly increases costs but also eliminates the advantage in size, causing considerable inconvenience for equipment installation and layout.

[0005] More seriously, current mainstream power supplies have a significant drawback: due to the lack of energy storage devices, they may not be able to provide sufficient energy to the contactors to maintain their holding state during short-term power outages or low-voltage ride-throughs. This will cause the contactors to malfunction, potentially leading to serious system problems and posing a significant threat to the stability and reliability of the entire electrical system. Therefore, how to solve these problems with existing DC contactor coil power supply methods, improve power utilization, reduce costs and size, and enhance system stability under abnormal grid conditions has become an urgent technical challenge. Summary of the Invention

[0006] Based on the problems mentioned above, the purpose of this invention is to provide a DC contactor drive power supply based on supercapacitor transient support, which solves the problems of low power utilization, high cost, large size, and inability to maintain the contactor holding state when the power grid is abnormal in the existing dual-coil power supply method for DC contactors.

[0007] This invention is achieved through the following technical solution:

[0008] This invention provides a DC contactor drive power supply based on supercapacitor transient support, comprising:

[0009] Buck-Boost circuit, current sampling circuit, control system, supercapacitor string, drive switch and contactor coil;

[0010] The Buck-Boost circuit and the current sampling circuit form a current loop, and the current loop and the voltage loop of the Buck-Boost circuit itself form a double closed-loop structure. The double closed-loop structure is used to perform constant current and constant voltage charging on the supercapacitor string.

[0011] When the contactor needs to operate, the control system controls the drive switch to open, causing the supercapacitor string to release the stored high-density charge and provide a large instantaneous current to the contactor coil.

[0012] In the above technical solution, the Buck-Boost circuit can stably output the rated coil supply voltage. Regardless of whether the input power supply voltage is lower or higher than the coil's rated value, it can ensure sufficient coil starting voltage while preventing coil damage due to excessive voltage. Based on this, a constant current output function is introduced through a current sampling circuit and a dual-closed-loop structure, achieving constant current and constant voltage charging of the supercapacitor. Compared to resistor-limited current methods, this charging method is more flexible, has fast charging capabilities, and reduces heat loss. Furthermore, the circuit is small in size and low in cost.

[0013] During operation, the supercapacitor string undergoes constant current-constant voltage charging via a Buck-Boost circuit, while the control system controls the drive switch to supply power to the contactor coil. When the contactor actuates, the control system opens the drive switch, releasing the high-density charge stored in the supercapacitor string to provide a large instantaneous current to the contactor coil, ensuring reliable contactor operation. After actuation, the contactor's charge is maintained by the Buck-Boost circuit.

[0014] The above technical solution allows the contactor coil's starting power to come from a supercapacitor string, eliminating the need for a high-power input power supply. The input power only needs to meet the contactor's holding current, thus achieving a power utilization rate of 90% to 100% and reducing input power supply costs and size. Furthermore, the energy stored in the supercapacitor string can maintain the normal operation of the control system and drive switches during short-term power outages or low-voltage ride-throughs, ensuring uninterrupted power to the contactor coil and maintaining normal contactor operation until the input power supply returns to normal. This effectively avoids system problems caused by short-term power outages or low-voltage ride-throughs.

[0015] In one optional embodiment, the Buck-Boost circuit includes: a first module, a second module, a chip U1, a third module, a fourth module, a resistor R7, a resistor R6, a capacitor C10, a resistor R4, a resistor R5, a MOSFET Q1, a resistor R2, and a capacitor C8.

[0016] The resistor R7 is connected in parallel with the capacitor C10 and in series with the resistor R6; the resistor R4 is connected in parallel between the resistor R3 and pin 5 of the chip U1; the resistor R5 is connected in parallel between the resistor R3 and pin 4 of the chip U1.

[0017] The MOSFET Q1 and the resistor R2 are connected in series to pin 19 of the chip U1, and the capacitor C8 is connected to pin 18 of the chip U1.

[0018] The first module includes capacitors C1, C2, C3, C4 and C5 connected in parallel. The first module is connected to pin 1 of the chip U1 through capacitor R3.

[0019] The second module includes a resistor R1, a capacitor C6, and a capacitor C7 connected in parallel, and the second module is connected to pin 17 of the chip U1;

[0020] The third module includes resistors R16, R17, R18, R14, and R15 connected in series, and capacitor C20 connected in parallel with resistors R18 and R14; the third module is connected to pin 1 of chip U1 through capacitor C9, to pin 7 of chip U1 through capacitor C16, to pin 5 of chip U1 through capacitor C11, and to pin 3 of chip U1 through resistor R8;

[0021] The fourth module includes diode D3, diode D1, resistor R9, inductor L1, MOSFET Q2, and capacitor C17, resistor R13, resistor R12, and resistor R10 connected in a ring in sequence. This ring is connected to diodes D3 and D1 and to pin 13 of chip U1. Diodes D3 and D1 are connected through inductor L1. MOSFET Q2 is connected in series with resistor R9 and then connected to pin 15 of chip U1. Inductor L1 is connected to pin 20 of chip U1.

[0022] In one alternative embodiment, the chip U1 is model LM5118MHXNOPB.

[0023] In one optional embodiment, both diode D1 and diode D3 are of model SBDB30100CT.

[0024] In one optional embodiment, the current sampling circuit includes: amplifier U15A, amplifier U15B, diode D21, resistor R129, resistor R124, resistor R121, resistor R125, resistor R134, resistor R140, resistor R131, and resistor R127.

[0025] Specifically, resistors R140 and R134 are connected in series and then connected to the non-inverting input terminal of amplifier U15B; resistor R131 is connected to the non-inverting input terminal of amplifier U15B; resistors R121 and R125 are connected in series and then connected in parallel between the inverting input terminal and the output terminal of amplifier U15B; and resistor R127 is connected to the inverting input terminal of amplifier U15B.

[0026] The output terminal of amplifier U15B is connected to the non-inverting input terminal of amplifier U15A, the output terminal of amplifier U15A is connected to diode D21, and resistor R124 is connected in parallel between the inverting input terminal of amplifier U15A and diode D21; diode D21 is connected to resistor R129.

[0027] In one optional embodiment, the supercapacitor string includes: a first capacitor group, a second capacitor group, a third capacitor group, a fourth capacitor group, a fifth capacitor group, a sixth capacitor group, a seventh capacitor group, an eighth capacitor group, a ninth capacitor group, a tenth capacitor group, an eleventh capacitor group, and a twelfth capacitor group connected in series; wherein each capacitor group includes a capacitor and a resistor, and the capacitor and the resistor are connected in parallel.

[0028] In one optional embodiment, the drive switch includes: switch JK1, diode D7, diode D6, inductor L6, MOSFET Q3, resistor R25, resistor R22, MOSFET Q6, resistor R113, and resistor R21.

[0029] Specifically, diode D7 is connected to pins 7 and 8 of switch JK1; diode D6 is connected in parallel between pins 1 and 2 of switch JK1; inductor L1 is connected to pin 2 of switch JK1; capacitor R25 is connected in parallel between the base and emitter of MOSFET Q3; the collector of MOSFET Q3 is connected to pin 1 of switch JK1; resistor R22 is connected to the collector of MOSFET Q6; resistor R113 is connected in parallel between the base and emitter of MOSFET Q6; and resistor R21 is connected to the base of MOSFET Q6.

[0030] In one optional embodiment, the switch JK1 is of model number HF115F / 005-1HS3AF.

[0031] In one optional embodiment, the DC contactor drive power supply further includes a rectifier circuit, which receives an external power supply, rectifies the external power supply, and inputs the rectified external power supply to the Buck-Boost circuit.

[0032] In one optional embodiment, the rectifier circuit includes: diodes D15, D16, D17, D18, D19, D20, and polarized capacitor E7.

[0033] Diode D15 is connected in series with diode D18; diode D16 is connected in series with diode D19; diode D17 is connected in series with diode D20.

[0034] The diodes D15 and D18, which are connected in series, are connected in parallel with the diodes D16 and D19, which are connected in series, and the diodes D17 and D20, which are connected in series.

[0035] The polarized capacitor E7 is connected in parallel with the diodes D17 and D20, which are connected in series.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] 1. Introducing a supercapacitor string utilizes the high power density of supercapacitors to provide instantaneous current for starting the DC contactor, overcoming the low utilization rate of ordinary direct-drive power supplies. Compared with lithium batteries and nickel-metal hydride batteries, the charging and discharging rates are slow and the cycle life is low.

[0038] 2. Utilizing the energy storage characteristics of supercapacitors, the system and contactors can maintain normal operation when the input power is interrupted for a short time, thus preventing system shutdown.

[0039] 3. The Buck-Boost circuit is incorporated, which utilizes the constant current charging technology of Buck-Boost to adapt to wide voltage input conditions in order to cope with complex power grid fluctuations. A current loop is introduced on the basis of the Buck-Boost circuit to achieve constant current and constant voltage charging for the supercapacitor, achieving low-cost fast charging and excellent thermal management, which can be used in on-board supercapacitor module products. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0041] Figure 1 This is a schematic diagram of the structure of a DC contactor drive power supply based on supercapacitor transient support provided in Embodiment 1 of the present invention;

[0042] Figure 2 This is a circuit diagram of a DC contactor drive power supply based on supercapacitor transient support provided in Embodiment 1 of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0044] Embodiment 1 of the present invention provides a DC contactor drive power supply based on supercapacitor transient support, such as... Figure 1 As shown, a DC contactor drive power supply based on supercapacitor transient support includes:

[0045] Buck-Boost circuit, current sampling circuit, control system, supercapacitor string, drive switch and contactor coil;

[0046] The Buck-Boost circuit and the current sampling circuit form a current loop, and the current loop and the voltage loop of the Buck-Boost circuit itself form a double closed-loop structure. The double closed-loop structure is used to perform constant current and constant voltage charging on the supercapacitor string.

[0047] When the contactor needs to operate, the control system controls the drive switch to open, causing the supercapacitor string to release the stored high-density charge and provide a large instantaneous current to the contactor coil.

[0048] It should be noted that, in response to the problems of low power utilization, high cost, large size, and inability to maintain the contactor's holding state when the power grid is abnormal in the existing dual-coil power supply method for DC contactors, a supercapacitor string is added to the DC contactor drive power supply. In scenarios where DC loads such as relays and DC circuit breakers require transient high current, the high power density characteristics of the supercapacitor are used to provide instantaneous current for the DC contactor to start, overcoming the problem of low power utilization of ordinary direct-drive power supplies. Compared with the slow charging and discharging rate and low cycle life of lithium batteries and nickel-metal hydride batteries, this method is also superior.

[0049] Meanwhile, since supercapacitors have energy storage characteristics, introducing a supercapacitor string into the DC contactor drive power supply can utilize these energy storage characteristics to maintain the normal operation of the control system and contactor when the input power is interrupted for a short time, thus preventing system shutdown.

[0050] In addition, this DC contactor drive power supply incorporates a Buck-Boost circuit. Utilizing Buck-Boost's constant current charging technology, the Buck-Boost circuit addresses input power fluctuations, and the current loop achieves constant current and constant voltage charging of the supercapacitor, resulting in low-cost fast charging and excellent thermal management. It can be used in onboard supercapacitor module products.

[0051] Specifically, the Buck-Boost circuit can stably output the rated coil supply voltage, ensuring sufficient coil startup voltage and preventing coil damage due to excessive voltage, regardless of whether the input power supply voltage is lower or higher than the coil's rated value. Building upon this, a constant current output function is introduced through a current sampling circuit and a dual-closed-loop structure, enabling constant current and constant voltage charging of the supercapacitor. Compared to resistor-limited current methods, this charging method is more flexible, features fast charging, and reduces heat loss, while also being smaller and less expensive.

[0052] During operation, the supercapacitor string undergoes constant current and constant voltage charging via a Buck-Boost circuit, while the control system controls the drive switch to supply power to the contactor coil. When the contactor actuates, the control system opens the drive switch, releasing the high-density charge stored in the supercapacitor string to provide a large instantaneous current to the contactor coil, ensuring reliable contactor operation. After actuation, the contactor's charge is maintained by the Buck-Boost circuit. Notably, constant current and constant voltage charging eliminates the need for dedicated chips with current feedback; ordinary DC-DC control chips can achieve constant current charging, offering greater selectivity and fewer limitations.

[0053] This technical solution allows the contactor coil's starting power to come from a supercapacitor string, eliminating the need for a high-power input power supply. The input power only needs to meet the contactor's holding current, thus achieving a power utilization rate of 90% to 100% and reducing input power supply costs and size. Furthermore, the energy stored in the supercapacitor string can maintain the normal operation of the control system and drive switches during short-term power outages or low-voltage ride-throughs, ensuring uninterrupted power to the contactor coil and maintaining normal contactor operation until the input power is restored. This effectively avoids system problems caused by short-term power outages or low-voltage ride-throughs.

[0054] In one optional embodiment, the Buck-Boost circuit includes: a first module, a second module, a chip U1, a third module, a fourth module, a resistor R7, a resistor R6, a capacitor C10, a resistor R4, a resistor R5, a MOSFET Q1, a resistor R2, and a capacitor C8.

[0055] The resistor R7 is connected in parallel with the capacitor C10 and in series with the resistor R6; the resistor R4 is connected in parallel between the resistor R3 and pin 5 of the chip U1; the resistor R5 is connected in parallel between the resistor R3 and pin 4 of the chip U1.

[0056] The MOSFET Q1 and the resistor R2 are connected in series to pin 19 of the chip U1, and the capacitor C8 is connected to pin 18 of the chip U1.

[0057] The first module includes capacitors C1, C2, C3, C4 and C5 connected in parallel. The first module is connected to pin 1 of the chip U1 through capacitor R3.

[0058] The second module includes a resistor R1, a capacitor C6, and a capacitor C7 connected in parallel, and the second module is connected to pin 17 of the chip U1;

[0059] The third module includes resistors R16, R17, R18, R14, and R15 connected in series, and capacitor C20 connected in parallel with resistors R18 and R14; the third module is connected to pin 1 of chip U1 through capacitor C9, to pin 7 of chip U1 through capacitor C16, to pin 5 of chip U1 through capacitor C11, and to pin 3 of chip U1 through resistor R8;

[0060] The fourth module includes diode D3, diode D1, resistor R9, inductor L1, MOSFET Q2, and capacitor C17, resistor R13, resistor R12, and resistor R10 connected in a ring in sequence. This ring is connected to diodes D3 and D1 and to pin 13 of chip U1. Diodes D3 and D1 are connected through inductor L1. MOSFET Q2 is connected in series with resistor R9 and then connected to pin 15 of chip U1. Inductor L1 is connected to pin 20 of chip U1.

[0061] The output of this Buck-Boost circuit also has a polarized capacitor E1 connected in parallel.

[0062] In one alternative embodiment, the chip U1 is model LM5118MHXNOPB.

[0063] In one optional embodiment, both diode D1 and diode D3 are of model SBDB30100CT.

[0064] In one optional embodiment, the current sampling circuit includes: amplifier U15A, amplifier U15B, diode D21, resistor R129, resistor R124, resistor R121, resistor R125, resistor R134, resistor R140, resistor R131, and resistor R127.

[0065] Specifically, resistors R140 and R134 are connected in series and then connected to the non-inverting input terminal of amplifier U15B; resistor R131 is connected to the non-inverting input terminal of amplifier U15B; resistors R121 and R125 are connected in series and then connected in parallel between the inverting input terminal and the output terminal of amplifier U15B; and resistor R127 is connected to the inverting input terminal of amplifier U15B.

[0066] The output terminal of amplifier U15B is connected to the non-inverting input terminal of amplifier U15A, the output terminal of amplifier U15A is connected to diode D21, and resistor R124 is connected in parallel between the inverting input terminal of amplifier U15A and diode D21; diode D21 is connected to resistor R129.

[0067] In one optional embodiment, the supercapacitor string includes: a first capacitor group, a second capacitor group, a third capacitor group, a fourth capacitor group, a fifth capacitor group, a sixth capacitor group, a seventh capacitor group, an eighth capacitor group, a ninth capacitor group, a tenth capacitor group, an eleventh capacitor group, and a twelfth capacitor group connected in series; wherein each capacitor group includes a capacitor and a resistor, and the capacitor and the resistor are connected in parallel.

[0068] It should be noted that the negative terminal of the supercapacitor string is connected to the Buck-Boost circuit through the current sensing resistor R88, and is also directly connected to the current sampling circuit.

[0069] The input and output of the supercapacitor string are connected in parallel with the output of the Buck-Boost circuit, and there is no undervoltage selection switch. When the input power is on, the Buck-Boost circuit provides energy to the load. When the input power is off, it automatically switches to the supercapacitor to provide energy to the load to maintain normal system operation.

[0070] In one optional embodiment, the drive switch includes: switch JK1, diode D7, diode D6, inductor L6, MOSFET Q3, resistor R25, resistor R22, MOSFET Q6, resistor R113, and resistor R21.

[0071] Specifically, diode D7 is connected to pins 7 and 8 of switch JK1; diode D6 is connected in parallel between pins 1 and 2 of switch JK1; inductor L1 is connected to pin 2 of switch JK1; capacitor R25 is connected in parallel between the base and emitter of MOSFET Q3; the collector of MOSFET Q3 is connected to pin 1 of switch JK1; resistor R22 is connected to the collector of MOSFET Q6; resistor R113 is connected in parallel between the base and emitter of MOSFET Q6; and resistor R21 is connected to the base of MOSFET Q6.

[0072] In one optional embodiment, the switch JK1 is of model number HF115F / 005-1HS3AF.

[0073] In one optional embodiment, the DC contactor drive power supply further includes a rectifier circuit, which receives an external power supply, rectifies the external power supply, and inputs the rectified external power supply to the Buck-Boost circuit.

[0074] In one optional embodiment, the rectifier circuit includes: diodes D15, D16, D17, D18, D19, D20, and polarized capacitor E7.

[0075] Diode D15 is connected in series with diode D18; diode D16 is connected in series with diode D19; diode D17 is connected in series with diode D20.

[0076] The diodes D15 and D18, which are connected in series, are connected in parallel with the diodes D16 and D19, which are connected in series, and the diodes D17 and D20, which are connected in series.

[0077] The polarized capacitor E7 is connected in parallel with the diodes D17 and D20, which are connected in series.

[0078] It should be noted that by inputting an external power supply compatible with both AC and DC into the rectifier circuit, the rectifier circuit is compatible with both DC current input from the transformer and AC current input from the switching power supply, thus realizing the function of drawing power from both AC and DC, making the application of DC contactor drive power supply more flexible.

[0079] In this embodiment, the DC contactor drive power supply is applied to a DC contactor power load with a coil specification of DC24V, a starting current of 13.5A, and a holding current of 0.45A. The external power supply is first input to a three-phase bridge rectifier circuit, which outputs a DC15V to 50V voltage after rectification. This voltage is then input to a Buck-Boost circuit, which converts the voltage to DC24V and outputs it after DC-DC conversion. A current sensing resistor is placed at the negative terminal of the Buck-Boost circuit output. The current sampling circuit samples and amplifies the current from the current sensing resistor through an operational amplifier, and sends the sampled voltage to the feedback terminal of the power chip. The operational amplifier parameters are set to achieve a constant current of 1A for charging the supercapacitor series. The Buck-Boost circuit output supplies power to the control system. When the contactor operates, the control system MCU instructs the drive switch intermediate relay to close, releasing the supercapacitor series charge to the contactor coil, allowing it to obtain a 13.5A instantaneous large current to complete the contactor's engagement. After the contactor coil reaches a steady state, it maintains a current of 0.45A. The 1A constant current capability of the Buck-Boost circuit ensures normal contactor engagement. When the power input is momentarily interrupted, the amount of electricity stored in the supercapacitor string can maintain the normal operation of the control system and drive switches, ensure that the contactor coil is not energized, and maintain the normal operation of the contactor until the input power is restored.

[0080] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A DC contactor drive power supply based on supercapacitor transient support, characterized in that, Buck-Boost circuit, current sampling circuit, control system, supercapacitor string, drive switch and contactor coil; The Buck-Boost circuit and the current sampling circuit form a current loop, and the current loop and the voltage loop of the Buck-Boost circuit itself form a double closed-loop structure. The double closed-loop structure is used to perform constant current and constant voltage charging on the supercapacitor string. When the contactor needs to operate, the control system controls the drive switch to open, causing the supercapacitor string to release the stored high-density electricity and provide a large instantaneous current to the contactor coil; The negative terminal of the supercapacitor string is connected to the Buck-Boost circuit through a current sensing resistor, and is also directly connected to the current sampling circuit.

2. The DC contactor drive power supply based on supercapacitor transient support according to claim 1, characterized in that, The Buck-Boost circuit includes: a first module, a second module, a chip U1, a third module, a fourth module, a resistor R7, a resistor R6, a capacitor C10, a resistor R4, a resistor R5, a MOSFET Q1, a resistor R2, and a capacitor C8. The resistor R7 is connected in parallel with the capacitor C10 and in series with the resistor R6; the resistor R4 is connected in parallel between the resistor R3 and pin 5 of the chip U1; the resistor R5 is connected in parallel between the resistor R3 and pin 4 of the chip U1. The MOSFET Q1 and the resistor R2 are connected in series to pin 19 of the chip U1, and the capacitor C8 is connected to pin 18 of the chip U1. The first module includes capacitors C1, C2, C3, C4 and C5 connected in parallel. The first module is connected to pin 1 of the chip U1 through capacitor R3. The second module includes a resistor R1, a capacitor C6, and a capacitor C7 connected in parallel, and the second module is connected to pin 17 of the chip U1; The third module includes resistors R16, R17, R18, R14, and R15 connected in series, and capacitor C20 connected in parallel with resistors R18 and R14; the third module is connected to pin 1 of chip U1 through capacitor C9, to pin 7 of chip U1 through capacitor C16, to pin 5 of chip U1 through capacitor C11, and to pin 3 of chip U1 through resistor R8; The fourth module includes diode D3, diode D1, resistor R9, inductor L1, MOSFET Q2, and capacitor C17, resistor R13, resistor R12, and resistor R10 connected in a ring in sequence. This ring is connected to diodes D3 and D1 and to pin 13 of chip U1. Diodes D3 and D1 are connected through inductor L1. MOSFET Q2 is connected in series with resistor R9 and then connected to pin 15 of chip U1. Inductor L1 is connected to pin 20 of chip U1.

3. The DC contactor drive power supply based on supercapacitor transient support according to claim 2, characterized in that, The chip U1 is model number LM5118MHXNOPB.

4. The DC contactor drive power supply based on supercapacitor transient support according to claim 2, characterized in that, Both diodes D1 and D3 are of model number SBDB30100CT.

5. The DC contactor drive power supply based on supercapacitor transient support according to claim 1, characterized in that, The current sampling circuit includes: amplifier U15A, amplifier U15B, diode D21, resistor R129, resistor R124, resistor R121, resistor R125, resistor R134, resistor R140, resistor R131, and resistor R127. Specifically, resistors R140 and R134 are connected in series and then connected to the non-inverting input terminal of amplifier U15B; resistor R131 is connected to the non-inverting input terminal of amplifier U15B; resistors R121 and R125 are connected in series and then connected in parallel between the inverting input terminal and the output terminal of amplifier U15B; and resistor R127 is connected to the inverting input terminal of amplifier U15B. The output terminal of amplifier U15B is connected to the non-inverting input terminal of amplifier U15A, the output terminal of amplifier U15A is connected to diode D21, and resistor R124 is connected in parallel between the inverting input terminal of amplifier U15A and diode D21; diode D21 is connected to resistor R129.

6. The DC contactor drive power supply based on supercapacitor transient support according to claim 1, characterized in that, The supercapacitor string includes: a first capacitor group, a second capacitor group, a third capacitor group, a fourth capacitor group, a fifth capacitor group, a sixth capacitor group, a seventh capacitor group, an eighth capacitor group, a ninth capacitor group, a tenth capacitor group, an eleventh capacitor group, and a twelfth capacitor group connected in series; wherein each capacitor group includes a capacitor and a resistor, and the capacitor and the resistor are connected in parallel.

7. The DC contactor drive power supply based on supercapacitor transient support according to claim 1, characterized in that, The drive switch includes: switch JK1, diode D7, diode D6, inductor L6, MOSFET Q3, resistor R25, resistor R22, MOSFET Q6, resistor R113, and resistor R21; Specifically, diode D7 is connected to pins 7 and 8 of switch JK1; diode D6 is connected in parallel between pins 1 and 2 of switch JK1; inductor L1 is connected to pin 2 of switch JK1; capacitor R25 is connected in parallel between the base and emitter of MOSFET Q3; the collector of MOSFET Q3 is connected to pin 1 of switch JK1; resistor R22 is connected to the collector of MOSFET Q6; resistor R113 is connected in parallel between the base and emitter of MOSFET Q6; and resistor R21 is connected to the base of MOSFET Q6.

8. The DC contactor drive power supply based on supercapacitor transient support according to claim 7, characterized in that, The switch JK1 is model HF115F / 005-1HS3AF.

9. The DC contactor drive power supply based on supercapacitor transient support according to claim 1, characterized in that, The DC contactor drive power supply also includes a rectifier circuit, which receives external power, rectifies the external power, and inputs the rectified external power to the Buck-Boost circuit.

10. The DC contactor drive power supply based on supercapacitor transient support according to claim 9, characterized in that, The rectifier circuit includes: diodes D15, D16, D17, D18, D19, D20 and polarized capacitor E7; Diode D15 is connected in series with diode D18; diode D16 is connected in series with diode D19; diode D17 is connected in series with diode D20. The diodes D15 and D18, which are connected in series, are connected in parallel with the diodes D16 and D19, which are connected in series, and the diodes D17 and D20, which are connected in series. The polarized capacitor E7 is connected in parallel with the diodes D17 and D20, which are connected in series.

Images