Portable direct-current power supply device

Abstract

The utility model discloses a portable direct-current power supply device, which comprises an alternating-current input socket, a 220V direct-current rectifier module, a K2 switching bridge test switch, an R1 balance bridge resistor, an R11 switching bridge resistor, a 220V direct-current output interface, a 110V direct-current rectifier module, a K4 switching bridge test switch, an R2 balance bridge resistor, an R21 switching bridge resistor and a 110V direct-current output interface. The alternating current input socket is connected with the K1 rectification module input switch and the K3 rectification module input switch through connecting wires and is respectively used as alternating current input of the 220V direct current rectification module and the 110V direct current rectification module. The device provides a temporary direct-current power supply for secondary equipment with different direct-current power supply requirements, realizes the functions of direct-current voltage measurement over the ground by a universal meter, insulation monitoring and real-time display of the direct-current voltage, grounding abnormity alarm and two-pole symmetrical grounding fault detection, and can timely discover the insulation abnormity condition of a secondary circuit.

Description

Technical Field

[0001] The utility model relates to the field of power supply devices, and particularly relates to a portable DC power supply device. Background Art

[0002] Secondary equipment is low-voltage electrical equipment that monitors, controls, adjusts, and protects primary equipment and provides operating conditions or production command signals for operators and maintenance personnel. It mainly includes relay protection and safety automatic devices, measurement and control devices, etc. Its working voltage is usually DC 220V or DC 110V.

[0003] In recent years, with the continuous development of new energy such as wind power and photovoltaic power, as well as the technical transformation of old equipment, the number of secondary equipment has increased significantly. However, when commissioning secondary equipment, the temporary DC power supply is often taken from the test power supply panel in the relay protection small room or the DC power supply output by the relay protection tester. The test power supply panel outputs adjustable DC voltage through a knob. When taking power, a multimeter is needed to confirm whether the output voltage reaches the target voltage, and then the DC power is led to the commissioning secondary equipment cabinet through secondary wires or cables. When using a relay protection tester to output DC, on the one hand, the relay protection tester is relatively bulky and inconvenient to move back and forth. On the other hand, the relay protection tester can only select to output DC or AC, which affects the commissioning efficiency of the relay protection device.

[0004] Moreover, neither of the two common methods for on-site commissioning mentioned above has insulation monitoring and alarm functions, and cannot reflect the DC voltage of the positive and negative poles to the ground. Without using a multimeter to measure the DC voltage to the ground, on-site commissioning personnel cannot timely discover the insulation conditions of the DC power supply and control power secondary circuits of secondary equipment during the commissioning process, which affects the quality of on-site work. If the grounding of the secondary circuit is not discovered, when the secondary equipment is connected to the formal DC power supply, it will affect the normal operation of the DC system and may even cause misoperation or refusal to operate of the equipment.

[0005] Therefore, it is necessary to design a portable DC power supply device to meet the actual needs of engineering applications. Summary of the Utility Model

[0006] The utility model provides a portable DC power supply device, which solves the problems in the background art that the temporary DC power supply for commissioning is taken from the test power supply panel or the relay protection tester, such as the inability to monitor the insulation of the DC power supply and the inability to reflect the DC voltage of the positive and negative poles to the ground, which affect the progress and quality of the engineering site. It has the characteristics of strong versatility, small and light, and simple operation.

[0007] The technical solution adopted by the utility model to solve its technical problems is as follows: A portable DC power supply device includes an AC input socket, a 220V DC rectification module, a K2 switching bridge test switch, an R1 balance bridge resistor, an R11 switching bridge resistor, a 220V DC output interface, a 110V DC rectification module, a K4 switching bridge test switch, an R2 balance bridge resistor, an R21 switching bridge resistor, and a 110V DC output interface. The AC input socket is connected to a K1 rectification module input switch and a K3 rectification module input switch through connecting wires and serves as the AC input for the 220V DC rectification module and the 110V DC rectification module respectively. One end of a V1 voltmeter and a V2 voltmeter are respectively connected to the DC +110V and -110V buses, and the other ends are grounded through a grounding interface. One end of a V3 voltmeter and a V4 voltmeter are respectively connected to the DC +55V and -55V buses, and the other ends are grounded through a grounding interface.

[0008] Preferably, the output of the 220V DC rectification module is connected to the 220V DC output interface through the DC +110V and -110V buses; the output of the 110V DC rectification module is connected to the 110V DC output interface through the DC +55V and -55V buses.

[0009] Preferably, one end of the R1 balance bridge resistor is connected to the DC +110V and -110V buses, and the other end is grounded through a grounding interface. The value of the R1 balance bridge resistor is 30 kΩ; one end of the R2 balance bridge resistor is connected to the DC +55V and -55V buses, and the other end is grounded through a grounding interface. The value of the R2 balance bridge resistor is 15 kΩ.

[0010] Preferably, one end of the K2 switching bridge test switch is connected to the DC +110V bus, and the other end is connected to the R11 switching bridge resistor and grounded through a grounding interface. The value of the R11 switching bridge resistor is 120 kΩ; one end of the K4 switching bridge test switch is connected to the DC +55V bus, and the other end is connected to the R21 switching bridge resistor and grounded through a grounding interface. The value of the R21 switching bridge resistor is 60 kΩ.

[0011] Preferably, both the K1 rectification module input switch and the K3 rectification module input switch have fuses.

[0012] Preferably, the 220V DC rectification module rectifies the AC 220V voltage into a DC 220V voltage; the 110V DC rectification module rectifies the AC 220V voltage into a DC 110V voltage.

[0013] Preferably, the V1 voltmeter, the V2 voltmeter, the V3 voltmeter, and the V4 voltmeter are digital display voltmeters.

[0014] Preferably, the 220V DC output interface, the grounding interface, and the 110V DC output interface are all 4mm banana plugs.

[0015] Preferably, the K2 switching bridge test switch and the K4 switching bridge test switch are push-button self-locking spring switches.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] A portable DC power supply device of the present utility model realizes the output of 220V or 110V DC voltage by inserting different rectifier module switches, and can provide a temporary DC power supply for debugging and other purposes for secondary devices with different DC power requirements. Based on the built balance bridge, the voltage values of the DC positive and negative poles to the ground can be measured by a multimeter, enabling the DC system to have functions of insulation monitoring of the DC output voltage, real-time voltage display, and ground fault alarm.

[0018] For the symmetrical ground fault occurring at both poles of the DC, a switching bridge test switch is set, and by inserting the switching bridge resistor, it is confirmed whether a symmetrical ground fault occurs at both poles.

[0019] This power supply device is small, light, easy to operate, and has strong versatility. It can promptly detect abnormal insulation of the secondary circuit to the ground, avoid affecting the formal DC power supply system and operating equipment, and improve the convenience and power acquisition efficiency in the engineering site. Brief Description of the Drawings

[0020] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0021] Figure 1 It is a schematic circuit diagram of a portable DC power supply device;

[0022] Figure 2 It is a schematic external view of a portable DC power supply device.

[0023] In the figure: 1. AC input socket, 2. K1 rectifier module insertion switch, 3. 220V DC rectifier module, 4. K2 switching bridge test switch, 5. R1 balance bridge resistor, 6. R11 switching bridge resistor, 7. V1 voltmeter, 8. V2 voltmeter, 9. 220V DC output interface, 10. K3 rectifier module insertion switch, 11. 110V DC rectifier module, 12. K4 switching bridge test switch, 13. R2 balance bridge resistor, 14. R21 switching bridge resistor, 15. Grounding interface, 16. V3 voltmeter, 17. V4 voltmeter, 18. 110V DC output interface. Detailed Embodiments

[0024] The drawings are only for illustrative purposes and should not be construed as a limitation to this patent;

[0025] The following further elaborates on the present utility model in conjunction with the accompanying drawings and embodiments.

[0026] As Figure 1 , Figure 2 shown, a portable DC power supply device includes AC input sockets 1, 220V DC rectification module 3, K2 switching bridge test switch 4, R1 balance bridge resistor 5, R11 switching bridge resistor 6, 220V DC output interface 9, 110V DC rectification module 11, K4 switching bridge test switch 12, R2 balance bridge resistor 13, R21 switching bridge resistor 14, 110V DC output interface 18. The AC input socket 1 is connected to the K1 rectification module input switch 2 and the K3 rectification module input switch 10 via connecting wires and serves as the AC input for the 220V DC rectification module 3 and the 110V DC rectification module 11 respectively. One end of the V1 voltmeter 7 and the V2 voltmeter 8 are respectively connected to the DC +110V and -110V buses, and the other end is grounded via the grounding interface 15, which can measure the voltages of the 220V DC positive and negative buses with respect to the ground. One end of the V3 voltmeter 16 and the V4 voltmeter 17 are respectively connected to the DC +55V and -55V buses, and the other end is grounded via the grounding interface 15, which can measure the voltages of the 110V DC positive and negative buses with respect to the ground.

[0027] The output of the 220V DC rectification module 3 is connected to the 220V DC output interface 9 via the DC +110V and -110V buses, providing 220V DC power for secondary equipment; the output of the 110V DC rectification module 11 is connected to the 110V DC output interface 18 via the DC +55V and -55V buses, providing 110V DC power for secondary equipment.

[0028] One end of the R1 balance bridge resistor 5 is connected to the DC +110V and -110V buses, and the other end is grounded via the grounding interface 15 to build a 220V DC system balance bridge. The value of the R1 balance bridge resistor 5 is taken as 30 kΩ, which can realize the measurement of the voltage values of the DC positive and negative poles with respect to the ground by a multimeter; one end of the R2 balance bridge resistor 13 is connected to the DC +55V and -55V buses, and the other end is grounded via the grounding interface 15 to build a 110V DC system balance bridge. The value of the R2 balance bridge resistor 13 is taken as 15 kΩ, which can realize the measurement of the voltage values of the DC positive and negative poles with respect to the ground by a multimeter.

[0029] One end of the K2 switching bridge test switch 4 is connected to the DC +110V bus, and the other end is connected to the R11 switching bridge resistor 6, which is grounded through the grounding interface 15. The value of the R11 switching bridge resistor 6 is 120 kΩ. The constructed switching bridge is used to detect the 220V DC two-pole symmetric grounding fault; One end of the K4 switching bridge test switch 12 is connected to the DC +55V bus, and the other end is connected to the R21 switching bridge resistor 14, which is grounded through the grounding interface 15. The value of the R21 switching bridge resistor 14 is 60 kΩ. The constructed switching bridge is used to detect the 110V DC two-pole symmetric grounding fault; The values of the R11 switching bridge resistor 6 and the R21 switching bridge resistor 14 are 120 kΩ and 60 kΩ respectively, so that when the switching bridge is put into or taken out, the absolute value of the differential voltage of the DC bus voltage fluctuation to the ground should be less than or equal to ±5% of the DC rated voltage.

[0030] Both the K1 rectifier module input switch 2 and the K3 rectifier module input switch 10 are equipped with fuses to prevent the overstepping tripping of the AC power supply in case of a short circuit.

[0031] The 220V DC rectifier module 3 rectifies the AC 220V voltage into a DC 220V voltage; The 110V DC rectifier module 11 rectifies the AC 220V voltage into a DC 110V voltage.

[0032] The V1 voltmeter 7, V2 voltmeter 8, V3 voltmeter 16, and V4 voltmeter 17 are digital display voltmeters, which are used to display the measured voltages of the output DC +110V, -110V buses and the DC +55V, -55V buses to the ground. The V1 voltmeter 7, V2 voltmeter 8, V3 voltmeter 16, and V4 voltmeter 17 can set the alarm threshold. When the output DC bus voltage to the ground exceeds the set threshold, an alarm is given by the buzzer inside the voltmeter.

[0033] The 220V DC output interface 9, the grounding interface 15, and the 110V DC output interface 18 are all 4mm banana plugs, which are convenient for connection with the power test line.

[0034] The K2 switching bridge test switch 4 and the K4 switching bridge test switch 12 are push-button self-locking spring switches.

[0035] When the utility model is in use, first ground the grounding interface 15 through a grounding wire. If a 220V DC power supply is used, first connect the positive and negative interfaces of the 220V DC output interface (9) to the corresponding positive and negative terminals of the secondary equipment power supply through a secondary test wire, then insert the power cord connected to the AC 220V mains into the AC input socket 1, and close the K1 rectifier module input switch 2. At this time, the output 220V DC power can provide the required power for the secondary equipment. The V1 voltmeter 7 and the V2 voltmeter 8 respectively display the DC positive and negative bus voltages to ground. During normal operation, the positive and negative bus voltages to ground should be balanced. The thresholds of the V1 voltmeter 7 and the V2 voltmeter 8 are set according to the voltages required by the "Maintenance Rules for Station DC Power Supply Systems" in the 24th volume of the "Regulations on Substation Maintenance Management of State Grid Corporation of China": "For a 220V DC system, the absolute value difference between the voltages of the two poles to ground does not exceed 40V or the insulation has not dropped below 25kΩ; for a 110V DC system, the absolute value difference between the voltages of the two poles to ground does not exceed 20V or the insulation has not dropped below 15kΩ". If grounding occurs and the voltage reaches the set threshold, the voltmeter buzzer will alarm. When the DC positive and negative bus voltages to ground are displayed as balanced, the K2 switching bridge test switch 4 can be closed to detect whether a symmetrical grounding fault of the two poles has occurred. If not, the K2 switching bridge test switch 4 can be disconnected, and the DC power supply device will continue to operate normally.

[0036] If a 110V DC power supply is used, first connect the positive and negative interfaces of the 110V DC output interface (18) to the corresponding positive and negative terminals of the secondary equipment power supply through a secondary test wire, then insert the power cord connected to the AC 220V mains into the AC input socket 1, and close the K3 rectifier module input switch 10. At this time, the output 110V DC power can provide the required power for the secondary equipment. The V3 voltmeter 16 and the V4 voltmeter 17 respectively display the DC positive and negative bus voltages to ground. During normal operation, the positive and negative bus voltages to ground should be balanced. The thresholds of the V3 voltmeter 16 and the V4 voltmeter 17 are set according to the voltages required by the "Maintenance Rules for Station DC Power Supply Systems" in the 24th volume of the "Regulations on Substation Maintenance Management of State Grid Corporation of China": "For a 220V DC system, the absolute value difference between the voltages of the two poles to ground does not exceed 40V or the insulation has not dropped below 25kΩ; for a 110V DC system, the absolute value difference between the voltages of the two poles to ground does not exceed 20V or the insulation has not dropped below 15kΩ". If grounding occurs and the voltage reaches the set threshold, the voltmeter buzzer will alarm. When the DC positive and negative bus voltages to ground are displayed as balanced, the K4 switching bridge test switch 12 can be closed to detect whether a symmetrical grounding fault of the two poles has occurred. If not, the K4 switching bridge test switch 12 can be disconnected, and the DC power supply device will continue to operate normally.

[0037] Obviously, the present utility model is not limited to the above embodiments, which are merely examples for clearly explaining the present utility model, rather than limitations on the implementation modes of the present utility model. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation modes here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the claims of the present utility model.

Claims

1. A portable DC power supply device, comprising an AC input socket (1), a 220V DC rectifier module (3), a K2 switching bridge test switch (4), an R1 balancing bridge resistor (5), an R11 switching bridge resistor (6), a 220V DC output interface (9), a 110V DC rectifier module (11), a K4 switching bridge test switch (12), an R2 balancing bridge resistor (13), an R21 switching bridge resistor (14), and a 110V DC output interface (18), characterized in that: The AC input socket (1) is connected to the K1 rectifier module input switch (2) and the K3 rectifier module input switch (10) via a connecting line to serve as the AC input of the 220V DC rectifier module (3) and the 110V DC rectifier module (11) respectively; one end of the V1 voltmeter (7) and the V2 voltmeter (8) are connected to the DC +110V and -110V busbars respectively, and the other end is grounded via a grounding interface (15); one end of the V3 voltmeter (16) and the V4 voltmeter (17) are connected to the DC +55V and -55V busbars respectively, and the other end is grounded via a grounding interface (15).

2. The portable DC power supply device according to claim 1, characterized in that: The output of the 220V DC rectifier module (3) is connected to the 220V DC output interface (9) via the DC +110V and -110V busbars; the output of the 110V DC rectifier module (11) is connected to the 110V DC output interface (18) via the DC +55V and -55V busbars.

3. The portable DC power supply device according to claim 1, characterized in that: One end of the R1 balancing bridge resistor (5) is connected to a DC +110V, -110V busbar, and the other end is grounded via a grounding interface (15). The R1 balancing bridge resistor (5) has a value of 30 kΩ. One end of the R2 balancing bridge resistor (13) is connected to a DC +55V, -55V busbar, and the other end is grounded via a grounding interface (15). The R2 balancing bridge resistor (13) has a value of 15 kΩ.

4. The portable DC power supply device according to claim 1, characterized in that: One end of the K2 switching bridge test switch (4) is connected to the DC +110V busbar, and the other end is connected to the R11 switching bridge resistor (6), which is grounded via the grounding interface (15). The R11 switching bridge resistor (6) has a value of 120kΩ; one end of the K4 switching bridge test switch (12) is connected to the DC +55V busbar, and the other end is connected to the R21 switching bridge resistor (14), which is grounded via the grounding interface (15). The R21 switching bridge resistor (14) has a value of 60kΩ.

5. The portable DC power supply device according to claim 1, characterized in that: The K1 rectifier module input switch (2) and the K3 rectifier module input switch (10) are both provided with fuses.

6. The portable DC power supply device according to claim 2, characterized in that: The 220V DC rectifier module (3) rectifies the 220V AC voltage into a 220V DC voltage; and the 110V DC rectifier module (11) rectifies the 220V AC voltage into a 110V DC voltage.

7. The portable DC power supply device according to claim 1, characterized in that: The V1 voltmeter (7), the V2 voltmeter (8), the V3 voltmeter (16), and the V4 voltmeter (17) are digital voltmeters.

8. The portable DC power supply device according to claim 4, characterized in that: The 220V DC output interface (9), the grounding interface (15), and the 110V DC output interface (18) are all 4mm banana plugs.

9. The portable DC power supply device according to claim 4, characterized in that: The K2 switching bridge test switch (4) and the K4 switching bridge test switch (12) are push-button self-locking spring switches.

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