CN216387230U - Power supply protection device for debugging secondary equipment - Google Patents

Abstract

The utility model provides a power supply protection device for secondary equipment debugging, which comprises a voltage division module, an on-off control module and a measurement and control module, wherein the voltage division module and the on-off control module are sequentially arranged between an external direct current system and a test load, a sampling end of the measurement and control module is connected with the external direct current system and/or the test load, and an output end of the measurement and control module is connected with a control end of the on-off control module, so that the on-off control module is controlled to cut off the connection between the external direct current system and the test load according to a sampling result of the measurement and control module. The utility model can effectively delay the time of protection misoperation caused by the fact that the alternating current voltage enters the direct current system, and cut off the power supply of the equipment before the protection misoperation is caused.

Description

Power supply protection device for debugging secondary equipment

Technical Field

The utility model relates to power equipment, in particular to a power supply protection device for debugging secondary equipment.

Background

The direct current system is a power supply system of secondary equipment of the transformer substation and is designed to be an ungrounded system, so that the situation that a ground fault forms a wrong loop to cause protection misoperation or operation failure accidents is avoided. In recent years of power accident analysis and research, many power production accidents are caused by the fact that the alternating-current voltage enters a direct-current system due to wiring errors of secondary equipment during debugging, and protection misoperation is caused; in 2018, the 500kV transformer substation of the Guangdong power grid has many accidents of protection misoperation caused by alternating current entering faults due to debugging protection intervals.

In order to detect the ground fault of the dc system, the dc system is generally provided with an artificial ground point, namely, an insulation monitoring device balance bridge. At present, there is a device for automatically cutting off a power supply when a secondary device is debugged for a ground fault, which is applied to the debugging work of the secondary device, monitors the power supply running state when the secondary device is debugged, and cuts off the power supply of the device in time if an alternating current ground fault occurs, so as to avoid the fault from influencing the safe running of a direct current system.

However, at present, such devices can only ensure that the response time is within 80ms, and cannot meet the requirement that "9.2.7 in" DL/T5222-2005 conductor and electrical appliance selection design technical regulation "requires a circuit breaker with the opening time not greater than 0.04s to be selected for a system with more than 110KV when the power system is stable and the fault is required to be quickly removed, so that the protection malfunction may be caused before the power supply of the device is cut off.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: aiming at the technical problems in the prior art, the utility model provides a power supply protection device for debugging secondary equipment, which can effectively delay the time of protection misoperation caused by the fact that alternating-current voltage enters a direct-current system, and cut off the power supply of the equipment before the protection misoperation is caused.

In order to solve the technical problems, the technical scheme provided by the utility model is as follows:

the utility model provides a power protection device for secondary equipment debugging, includes partial pressure module, on-off control module and observes and controls the module, partial pressure module and on-off control module set gradually between outside direct current system and experimental load, observe and control the sampling end of module and outside direct current system and/or experimental load connection, observe and control the output of module and the control end of on-off control module and connect, make on-off control module is according to the sampling result of observing and controlling the module, controlled outside direct current system and the connection of experimental load of cutting off.

Preferably, the voltage division module includes an inductor for voltage division and a capacitor for filtering, a positive bus and a negative bus of an external dc system are connected to the on-off control module through one inductor, and each inductor is grounded through one capacitor.

Preferably, the measurement and control module comprises a controller unit, a direct current acquisition unit and an alternating current acquisition unit, an external direct current system is connected with the input end of the direct current acquisition unit through a voltage division module, an external test load is connected with the input end of the alternating current acquisition unit, and the output ends of the direct current acquisition unit and the alternating current acquisition unit are respectively connected with the input end of the controller unit.

Preferably, the dc acquisition unit includes a first isolation amplifier and a first operational amplifier, an input end of the first isolation amplifier is connected to a positive bus and a negative bus of an external dc system through the voltage division module, and an output end of the first isolation amplifier is connected to an input end of the controller unit through the first operational amplifier.

Preferably, the alternating current acquisition unit comprises a second isolation amplifier and a second operational amplifier, an input end of the second isolation amplifier is connected with a positive electrode or a negative electrode of an external test load through a voltage division module, and an output end of the first isolation amplifier is connected with an input end of the controller unit through a first operational amplifier.

Preferably, the measurement and control module further comprises an information display unit, and the output end of the controller unit is connected with the input end of the display unit.

Preferably, the display unit comprises a touch screen and/or an indicator light.

Preferably, the measurement and control module further comprises a communication unit, and the controller unit is connected with the communication unit in a bidirectional mode.

Preferably, the measurement and control module further comprises a storage unit, and the communication unit is in bidirectional connection with the storage unit through the controller unit.

Preferably, the voltage conversion module is further included, an input end of the voltage conversion module is connected with an output end of the voltage division module, and an output end of the voltage conversion module is connected with a power supply end of the measurement and control module.

Compared with the prior art, the utility model has the advantages that:

1. the utility model adds the voltage division module which can divide the voltage when the alternating voltage enters, so that the voltage division of the relay coil of the direct current system is small enough and is not enough to cause the protection misoperation, and the on-off control module controls to cut off the connection between the external direct current system and the test load according to the sampling result of the measurement and control module, thereby playing the role of protecting the direct current system as the power supply when the alternating voltage enters and having no influence on the direct current system.

2. The voltage division module is provided with an inductor and a capacitor aiming at a positive bus and a negative bus of a direct current system respectively, the inductor has a blocking effect on the alternating current which flows in and has a voltage division effect, the capacitor has a filtering effect, the inductor blocks the alternating current conduction when the alternating current flows in, and the capacitor releases the alternating current energy, so that the alternating current is prevented from entering the external direct current system.

3. The measurement and control module comprises a direct current acquisition unit and an alternating current acquisition unit, wherein the direct current acquisition unit can acquire the bus voltage of a direct current system, the alternating current acquisition unit can acquire the voltage of a test load, and whether the test load has alternating current entering conditions or not can be judged by comparing the results of the direct current acquisition unit and the alternating current acquisition unit.

Drawings

Fig. 1 is a circuit structure diagram according to a first embodiment of the utility model.

Fig. 2 is a block diagram of a first embodiment of the present invention.

Fig. 3 is a circuit structure diagram of a dc acquisition unit according to a first embodiment of the utility model.

Fig. 4 is a circuit structure diagram of an ac acquisition unit according to a first embodiment of the present invention.

Illustration of the drawings: the device comprises a 1-voltage division module, a 2-on-off control module, a 3-measurement and control module, a 4-voltage conversion module, a 31-controller unit, a 32-direct current acquisition unit, a 33-alternating current acquisition unit, a 34-display unit, a 35-communication unit, a 36-storage unit and a 37-driving unit.

Detailed Description

The utility model is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the utility model.

Example one

As shown in fig. 1 and fig. 2, this embodiment provides a power protection device for secondary equipment debugging, including setting up partial pressure module 1, on-off control module 2 and observing and controlling module 3 in the box, partial pressure module 1 and on-off control module 2 set gradually between outside direct current system and experimental load, observe and control module 3's sampling end and outside direct current system and/or experimental load and connect, observe and control module 3's output and on-off control module 2's control end and connect, make on-off control module 2 is according to observing and controlling module 3's sampling result, the connection of controlled outside direct current system and experimental load of cutting off.

The partial pressure module 1 of this embodiment can carry out the partial pressure when having alternating voltage to scurry for direct current system relay coil's partial pressure is enough little, is not enough to arouse the protection malfunction, and on-off control module 2 is according to the sampling result of observing and controling module 3 simultaneously, and the connection of outside direct current system and test load is cut off in the controlled way, thereby plays alternating voltage when scurry the guard action to the direct current system as the power, and can not lead to the fact the influence to direct current system.

In this embodiment, the voltage dividing module 1 includes an inductor for dividing voltage and a capacitor for filtering, a positive bus and a negative bus of an external dc system are both connected to the on-off control module 2 through one inductor, and each inductor is grounded through one capacitor. Specifically, as shown in fig. 1, the voltage dividing module 1 includes an inductor L1, an inductor L2, a capacitor C1, and a capacitor C2, a positive bus and a negative bus of the dc system are connected to the on-off control module 2 through the inductor L1 and the inductor L2, respectively, the inductor L1 is grounded through the capacitor C1, the inductor L2 is grounded through the capacitor C2, the inductor L1 and the inductor L2 block ac conduction of the positive bus and the negative bus when ac flows in, the inductor L1 releases ac power through the capacitor C1, and the inductor L2 releases ac power through the capacitor C2, thereby preventing ac from entering the external dc system.

As shown in fig. 2, the measurement and control module 3 of this embodiment includes a controller unit 31, a dc collecting unit 32 and an ac collecting unit 33, an external dc system is connected to the input terminal of the dc collecting unit 32 through a voltage dividing module 1, an external test load is connected to the input terminal of the ac collecting unit 33, and the output terminals of the dc collecting unit 32 and the ac collecting unit 33 are connected to the input terminal of the controller unit 31. The direct current acquisition unit 32 can acquire the bus voltage of a direct current system, the alternating current acquisition unit 33 can acquire the voltage of a test load, and the controller unit 31 can judge whether the test load has the situation of alternating current entering or not by comparing the acquisition results of the direct current acquisition unit 32 and the alternating current acquisition unit 33, so that the on-off control module 2 can be controlled to be continuously kept on and off.

In this embodiment, three dc acquisition units 32 are provided, which are respectively used to acquire a bus voltage U, a bus voltage V + over-ground voltage V + and a bus voltage V + under-ground voltage V-, as shown in fig. 3, each dc acquisition unit 32 includes an isolation amplifier U7, an operational amplifier U6A and an AD sampling chip (not shown), the isolation amplifier U7 employs an AMC1200 chip, wherein pin 1 is connected to a 4V power supply and grounded through a capacitor C30, pin 2 is connected to a positive voltage KM + to be input through a resistor R32, a resistor R30 and a resistor R31 in sequence, an output terminal of resistor R31 is grounded through a capacitor C31, an output terminal of resistor R30 is grounded through capacitors C32 and R36 connected in parallel, an output terminal of resistor R32 is grounded through a capacitor C33, pins 3 and 4 are connected to a negative voltage KM-to be input, pins 3 and 4 are grounded, a pin 5 is grounded, a pin 6 is grounded through a capacitor C35, the No. 7 pin is grounded through a capacitor C34, the No. 8 pin is connected with a 5V power supply through an inductor L6, and is grounded through a capacitor C29, an AD8552 chip is adopted by the operational amplifier U6A, wherein the No. 1 pin is connected with the AD sampling chip through a resistor R34, the output end of the resistor R34 is grounded through a capacitor C37, the No. 1 pin is connected with the No. 2 pin through a parallel capacitor C26, a resistor R28 and a resistor R29, the No. 2 pin is connected with the No. 6 pin of the isolation amplifier U7 through a resistor R35, the No. 3 pin is connected with the No. 7 pin of the isolation amplifier U7 through a resistor R33, the No. 3 pin is connected with a 2.5V power supply through a resistor R39, and is grounded through a parallel resistor R38 and a capacitor C38, the No. 8 pin is grounded through an electrolytic capacitor C39 and a capacitor C40, and is connected with a 3.3V power supply through an inductor L8.

In the dc acquisition unit 32, a resistor at a front stage of the isolation amplifier U7 divides an input dc signal, a weak dc voltage signal after division is isolated and amplified by the isolation amplifier U7, and then is operational and amplified by the operational amplifier U6A, the amplified signal enters an AD sampling chip for sampling, and the AD sampling chip finally sends a sampling signal to the controller unit 31.

For the dc acquisition unit 32 for acquiring the bus voltage U, the input positive voltage KM + is the voltage of the positive bus of the dc system, and the input negative voltage KM-is the voltage of the negative bus of the dc system, so in the dc acquisition unit 32, the pin No. 2 of the isolation amplifier U7 is connected to the inductor L1 of the voltage division module 1 sequentially through the resistor R32, the resistor R30 and the resistor R31, and the pins No. 3 and No. 4 are connected to the inductor L2 of the voltage division module 1 respectively.

For the direct current acquisition unit 32 for acquiring the bus voltage V + directly opposite to the ground, the voltage input direction of the direct current acquisition unit 32 is the same as that of the direct current acquisition unit 32 for acquiring the bus voltage U, so in the direct current acquisition unit 32, the pin No. 2 of the isolation amplifier U7 is connected with the inductor L1 of the voltage division module 1 sequentially through the resistor R32, the resistor R30 and the resistor R31, and the pins No. 3 and No. 4 are connected with the inductor L2 of the voltage division module 1 respectively.

For the direct current acquisition unit 32 for acquiring the negative voltage V-to-ground of the bus, the voltage input direction of the direct current acquisition unit 32 is opposite to that of the direct current acquisition unit 32 for acquiring the bus voltage U, so in the direct current acquisition unit 32, the pin 3 of the isolation amplifier U7 is connected with the inductor L1 of the voltage division module 1 sequentially through the resistor R32, the resistor R30 and the resistor R31, and the pins 2 and 4 are respectively connected with the inductor L2 of the voltage division module 1.

In this embodiment, two ac collecting units 33 are provided, which are respectively used to collect the ac voltage Vac + of the positive electrode of the test load and the ac voltage Vac + of the negative electrode of the test load, as shown in fig. 4, the ac collecting unit 33 includes an isolation amplifier U1, an operational amplifier U3A and an AD sampling chip (not shown), the isolation amplifier U1 employs an AMC1200 chip, wherein pin 1 is connected to a 4.5V power supply and grounded through a capacitor C13, pin 2 is connected to a positive voltage Uac + to be input through a resistor R9, a resistor R8 and a resistor R7 in sequence, an output end of the resistor R8 is grounded through a resistor R24, an output end of the resistor R9 is grounded through a capacitor C15, pins 3 and 4 are grounded respectively, pin 5 is grounded, pin 6 is grounded through a capacitor C7, pin 7 is grounded through a capacitor C8, pin 8 is connected to a 5V power supply through an inductor and grounded through a capacitor C4, the operational amplifier U3A adopts an AD8552 chip, wherein the pin No. 1 is connected with the AD sampling chip through a resistor R15, the output end of a resistor R15 is grounded through a capacitor C9, the pin No. 1 is also connected with the pin No. 2 through a capacitor C1, a resistor R1 and a resistor R3 which are connected in parallel, the pin No. 2 is connected with the pin No. 6 of the isolation amplifier U1 through a resistor R21, the pin No. 3 is connected with the pin No. 7 of the isolation amplifier U1 through a resistor R13, the pin No. 3 is also connected with a 2.5V power supply through a resistor R30 and is grounded through a resistor R28, the pin No. 8 is grounded through an electrolytic capacitor C20 and a capacitor C28 which are connected in parallel, and is connected with the 3.3V power supply through an inductor L4.

The ac acquisition unit 33 and the front stage of the isolation amplifier U1 divide the input ac signal, the divided weak ac voltage signal is isolated and amplified by the isolation amplifier U1, and then is operational and amplified by the operational amplifier U3A, the amplified signal enters the AD sampling chip for sampling, and the AD sampling chip finally sends the sampling signal to the controller unit 31.

In the ac collecting unit 33 for collecting the test load positive electrode-to-ground ac voltage Vac +, the positive voltage Uac + inputted thereto is the test load positive electrode voltage, and therefore, in the ac collecting unit 33, the pin No. 2 of the isolation amplifier U1 is connected to the test load positive electrode through the resistor R9, the resistor R8, and the resistor R7 in this order.

The voltage input direction of the alternating current acquisition unit 33 for acquiring the alternating current voltage Vac < - > of the negative pole of the test load to the ground is opposite to that of the alternating current acquisition unit 33 for acquiring the alternating current voltage Vac < + > of the positive pole of the test load to the ground, so that in the alternating current acquisition unit 33, the No. 3 pin of the isolation amplifier U1 is connected with the positive pole of the test load sequentially through the resistor R9, the resistor R8 and the resistor R7, and the No. 2 pin and the No. 4 pin are respectively grounded.

In this embodiment, the controller unit 31 selects the STM32F103RCT6, which is a 32-bit CPU of STM 32M 3 series, and has a main frequency of 72MHz, 256K internal Flash, 64K internal RAM, and 3 in-chip and external rich 24-way 12-bit ADCs, 2 UARTs, 3-way SPIs, and 1-way SDIO. With LQFP64 packaging, there are a maximum of 51 IOs. And the control requirement of the equipment is met.

As shown in fig. 2, the measurement and control module 3 of this embodiment further includes an information display unit 34, and an output end of the controller unit 31 is connected to an input end of the display unit 34. The display element 34 of this embodiment includes one or more in touch-sensitive screen and the pilot lamp, and the touch-sensitive screen adopts 5 cun touch-sensitive screens of Guangzhou polychrome science and technology industry serial ports, the model: and the DC80480B050_03TF meets the basic requirements of the human-computer interaction of the equipment. The indicating lamp comprises one or more of a power LED indicating lamp, an operation LED indicating lamp and a fault LED indicating lamp, so that field personnel can visually observe the operation state of the equipment.

As shown in fig. 2, the measurement and control module 3 of this embodiment further includes a communication unit 35, and the controller unit 31 and the communication unit 35 are connected in a bidirectional manner. The communication unit 35 of the present embodiment includes 1 or more of a 485 communication circuit and a USB data interface circuit to meet the requirements of upper computer monitoring and USB disk copy data.

As shown in fig. 2, the measurement and control module 3 of this embodiment further includes a storage unit 36, the communication unit 35 is bidirectionally connected to the storage unit 36 through the controller unit 31, so as to implement data reading and writing, the storage unit 36 in this embodiment selects an SDINBDG4-8G chip, and the 8G storage capacity meets the data recording requirement of more than 200 sets of 10 s.

As shown in fig. 2, the power protection device in this embodiment further includes a voltage conversion module 4, an input end of the voltage conversion module 4 is connected to an output end of the voltage dividing module 1, and an output end of the voltage conversion module 4 is connected to a power supply end of the measurement and control module 3. In this embodiment, the voltage conversion module 4 is a power module with model number LH15-10B 1215W and a DC/DC converter with model number LH15-10B 1215W, wherein the DC/DC converter is 12V to 5V, 12V to 3.3V, and 12V to 15V, and parameters of LH15-10B 1215W are input voltages: 100-370 VDC output: 12V/1250mA, realize wide range input, guarantee 110V system and 220V system in the direct current system are general. The DC/DC converter for converting 12V into 5V, converting 12V into 3.3V and converting 12V into 15V generates a 5V power supply which is used for supplying power to the direct current acquisition unit 32 and the alternating current acquisition unit 33 in the measurement and control module 3, the 3.3V power supply is used for supplying power to the digital circuit in the measurement and control module 3, and the 15V power supply is used for switching on and off the working power supply of the control module 2.

In this embodiment, the on-off control module 2 employs an MOS transistor controller and a driving unit, the output end of the controller unit 31 is connected to the MOS transistor controller through the driving unit, the model of the MOS transistor controller is IRFP360PBF (23a 400V), which can provide a large current switching function and is used to supply power to the test load, and when the test load has a fault, the connection is disconnected. Correspondingly, the driving unit is a MOS transistor driving control circuit designed by using electronic components, so the controller unit 31 outputs a control signal to the MOS transistor driving control circuit to drive the MOS transistor controller to operate.

Example two

The present embodiment is basically the same as the first embodiment, except that an input terminal corresponding to a positive bus, a negative bus, and a zero line of a dc system is provided on a box of the power protection device for debugging a secondary device in the present embodiment, and an output terminal corresponding to a positive electrode and a negative electrode of a test load is further provided, in the voltage division module 1, an input end of an inductor L1 is connected to the input terminal corresponding to the positive bus, an input end of an inductor L2 is connected to the input terminal corresponding to the negative bus, a positive output end of the on-off control module 2 is connected to the output terminal corresponding to the positive electrode of the test load, and a negative output end of the on-off control module 2 is connected to the output terminal corresponding to the negative electrode of the test load.

The input terminal and the output terminal are provided with interfaces which are convenient to plug and pull, such as threaded interfaces, quick-release ports or bayonets, so that the equipment can be conveniently overhauled and replaced.

The foregoing is considered as illustrative of the preferred embodiments of the utility model and is not to be construed as limiting the utility model in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.

Claims (10)

1. The utility model provides a power protection device for secondary equipment debugging, a serial communication port, including partial pressure module (1), on-off control module (2) and observe and control module (3), partial pressure module (1) and on-off control module (2) set gradually between outside direct current system and experimental load, the sample terminal and outside direct current system and/or experimental load of observing and controlling module (3) are connected, the output of observing and controlling module (3) and the control end of on-off control module (2) are connected, make on-off control module (2) are according to the sampling result of observing and controlling module (3), controlled outside direct current system and the connection of experimental load of cutting off.

2. The power protection device for secondary equipment debugging of claim 1, wherein the voltage dividing module (1) comprises an inductor for voltage division and a capacitor for filtering, a positive bus and a negative bus of an external direct current system are connected with the on-off control module (2) through one inductor, and each inductor is grounded through one capacitor.

3. The power protection device for secondary equipment debugging of claim 1, wherein the measurement and control module (3) comprises a controller unit (31), a direct current acquisition unit (32) and an alternating current acquisition unit (33), an external direct current system is connected with the input end of the direct current acquisition unit (32) through a voltage division module (1), an external test load is connected with the input end of the alternating current acquisition unit (33), and the output ends of the direct current acquisition unit (32) and the alternating current acquisition unit (33) are respectively connected with the input end of the controller unit (31).

4. The power protection device for secondary equipment debugging of claim 3, wherein the DC acquisition unit (32) comprises a first isolation amplifier, a first operational amplifier and a first sampling chip, wherein the input end of the first isolation amplifier is connected with the positive bus and the negative bus of the external DC system through the voltage division module (1), the output end of the first isolation amplifier is connected with the input end of the first sampling chip through the first operational amplifier, and the output end of the first sampling chip is connected with the input end of the controller unit (31).

5. The power protection device for secondary equipment debugging of claim 3, wherein said AC acquisition unit (33) comprises a second isolation amplifier, a second operational amplifier and a second sampling chip, wherein the input end of said second isolation amplifier is connected with the positive pole or negative pole of the external test load through the voltage division module (1), the output end of said second isolation amplifier is connected with the input end of the second sampling chip through the second operational amplifier, and the output end of said second sampling chip is connected with the input end of the controller unit (31).

6. The power protection device for secondary equipment debugging of claim 3, wherein said measurement and control module (3) further comprises an information display unit (34), and the output end of said controller unit (31) is connected with the input end of said display unit (34).

7. The power protection device for secondary equipment commissioning as recited in claim 6, wherein said display unit (34) comprises a touch screen and/or an indicator light.

8. The power protection device for secondary equipment debugging of claim 3, wherein said measurement and control module (3) further comprises a communication unit (35), and said controller unit (31) and said communication unit (35) are bidirectionally connected.

9. The power protection device for secondary equipment debugging of claim 8, wherein said measurement and control module (3) further comprises a storage unit (36), and said communication unit (35) is bidirectionally connected with said storage unit (36) through a controller unit (31).

10. The power protection device for secondary equipment debugging according to any one of claims 1 to 9, further comprising a voltage conversion module (4), wherein an input end of the voltage conversion module (4) is connected with an output end of the voltage division module (1), and an output end of the voltage conversion module (4) is connected with a power supply end of the measurement and control module (3).

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