CN115912285A - Anti-reverse power transmission safety isolation device used between power distribution network line and test instrument - Google Patents

Abstract

The invention discloses an anti-reverse power transmission safety isolation device used between a distribution network line and a testing instrument. The current and voltage conditions on the line between a connection end and the second connection end used to connect the test instrument, and judge whether the voltage exceeds the limit value of the voltage or the current exceeds the limit value of the current, or the current and voltage respectively reach the set value And when the current flows to the isolation device, the load switch provided between the first connection end and the second connection end is controlled to open and the grounding knife switch is closed to perform a protection action. Therefore, the present invention can actively isolate the line voltage according to the voltage and current conditions between the distribution network line and the test instrument, thereby ensuring the personal and life safety of the test instrument side.

Description

Anti-reverse power transmission safety isolation device used between distribution network lines and test instruments

technical field

The invention relates to the technical field of power distribution safety, in particular to an isolation device used between a power distribution line and a testing instrument.

Background technique

When the distribution line of the power system fails or is regularly repaired, it is necessary to connect various test instruments to the distribution network line to find line faults or test various parameters, and the operation and maintenance personnel operate or test data on the test instruments , once the reverse power transmission occurs on the line, there will be accidents that endanger the personal and life safety of operation and maintenance.

Contents of the invention

The object of the present invention is to provide an anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument. When the test instrument tests the distribution network line, according to the distance between the distribution network line and the test instrument Actively isolate the line voltage to ensure the personal safety of the testing instrument side.

In order to realize the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

An anti-reverse power transmission safety isolation device used between a distribution network line and a test instrument, comprising:

The first connection end is used to connect to the distribution network line;

The second connection end is used to connect the test instrument;

Fuses, load switches, control modules, voltage detection circuits, current detection circuits and grounding circuits;

Wherein, one end of the fuse is connected to the first connection end, the other end is connected to the static contact of the load switch, and the movable contact of the load switch is connected to the second connection end, and the The second connecting end is connected to the grounding line;

The voltage detection circuit is configured to detect a voltage signal of at least one node between the first connection terminal and the second connection terminal, and transmit the detected voltage detection data to the control module;

The current detection circuit is configured to detect a current signal of at least one node between the first connection end and the second connection end, and transmit the detected current detection data to the control module;

The control module is configured to determine whether the effective value of the voltage signal on the line side of the distribution network exceeds a voltage limit value according to the voltage detection data, so as to determine whether to control and execute a protection action; or, according to the current detection data , judging whether the effective value of the current signal flowing through the isolation device exceeds the limit value of the current, so as to determine whether to control the execution of the protection action; or, according to the voltage detection data and the current detection data, simultaneously judge the line side of the distribution network When the effective value of the voltage signal reaches the set value, the effective value of the current signal on the line side of the distribution network reaches the set value, and the current on the line side of the distribution network flows to the isolation device, then the control executes the protection action; wherein, the control module The protection action is executed by controlling the disconnection of the load switch and the closure of the grounding switch on the grounding line.

According to a specific implementation, the present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument, and the control module is used to judge the fuse according to the voltage detection data Whether it is disconnected, and whether the load switch and the grounding switch are working normally.

According to a specific embodiment, the present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument, and the voltage detection circuit includes: a first voltage divider, a second voltage divider and A third voltage divider; wherein, one end of the first voltage divider is connected to one end of the fuse connected to the first connection end, and one end of the second voltage divider is connected to the fuse to connect to the load switch One end of the static contact, one end of the third voltage divider is connected to one end of the load switch moving contact, and the other ends of the first voltage divider, the second voltage divider and the third voltage divider are commonly grounded; The sampling ends of the first voltage divider, the second voltage divider and the third voltage divider are respectively connected to the analog input terminals of different channels of an analog-to-digital conversion module, and the digital output terminals of the corresponding channels of the analog-to-digital conversion module are respectively connected to to the control module.

According to a specific implementation mode, the present invention is used in an anti-reverse power transmission safety isolation device between a distribution network line and a test instrument, and the current detection circuit includes: a first current transformer; wherein, the first A current transformer is arranged on the line between the first connection end and the second connection end, the sampling end of the first current transformer is connected to the analog input end of one channel of the analog-to-digital conversion module, The digital output terminals of the corresponding channels of the analog-to-digital conversion module are connected to the control module.

According to a specific embodiment, the anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention further includes: a wireless communication module; and, the wireless communication module is connected to the control module, It is used to receive the control instruction sent by the external wireless terminal and transmit it to the control module, and transmit the status data processed by the control module to the external wireless terminal;

The control module is configured to respond to the control instruction, control the disconnection of the load switch and the closure of the grounding switch on the grounding line or select the control logic for performing a protection action.

According to a specific embodiment, the anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention further includes: a status indication module and a battery module; wherein, the status indication module and the control The module connection is used to perform corresponding status indication according to the status data processed by the control module; wherein, the status data includes the operation of the battery module, the load switch, the grounding switch and the fuse Status data, as well as device side live status data and reverse power transmission status data;

The battery module is used to provide working power for the anti-reverse power transmission safety isolation device.

According to a specific embodiment, the present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument, the load switch is a normally open contact, and the grounding switch is a normally closed style contacts.

According to a specific implementation manner, the present invention is used in an anti-reverse power transmission safety isolation device between a distribution network line and a test instrument, and the melting core of the high-voltage fuse is arranged in a replaceable manner.

According to a specific implementation, the present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument, and the first connection end and the second connection end are respectively connected with a high-voltage connection line .

According to a specific embodiment, the anti-reverse power transmission safety isolation device used between distribution network lines and test instruments in the present invention includes: an outer shell, and a base arranged at the bottom of the outer shell; wherein, the outer shell The body is used to accommodate the electrical part of the isolating device, and the base is an insulating and retractable structure.

Compared with prior art, the beneficial effect of the present invention:

The present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument. The control module collects the first connection end for connecting the distribution network line and Test the current and voltage on the line between the second connection terminals of the instrument, and judge that the voltage exceeds the limit value of the voltage or the current exceeds the limit value of the current, or when the current and voltage respectively reach the set value and the current flows to the isolation device, Controlling the disconnection of the load switch provided between the first connection end and the second connection end and the closure of the grounding knife switch to perform protection actions. Therefore, the present invention can actively isolate the line voltage according to the voltage and current conditions between the distribution network line and the test instrument, thereby ensuring the personal and life safety of the test instrument side.

Description of drawings:

FIG. 1 is a schematic diagram of the internal structure of an isolation device provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of a status prompt module provided by an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

As shown in Figure 1, the present invention is an anti-reverse power transmission safety isolation device used between distribution network lines and test instruments, which includes:

The first connection end is used to connect to the distribution network line;

The second connection end is used to connect the test instrument;

Fuses, load switches, control modules, voltage detection circuits, current detection circuits and grounding circuits;

Wherein, one end of the fuse is connected to the first connection end, the other end is connected to the static contact of the load switch, and the movable contact of the load switch is connected to the second connection end, and the The second connecting end is connected to the grounding line;

The voltage detection circuit is configured to detect a voltage signal of at least one node between the first connection terminal and the second connection terminal, and transmit the detected voltage detection data to the control module;

The current detection circuit is configured to detect a current signal of at least one node between the first connection end and the second connection end, and transmit the detected current detection data to the control module;

The control module is configured to determine whether the effective value of the voltage signal on the line side of the distribution network exceeds a voltage limit value according to the voltage detection data, so as to determine whether to control and execute a protection action; or, according to the current detection data , judging whether the effective value of the current signal flowing through the isolation device exceeds the limit value of the current, so as to determine whether to control the execution of the protection action; or, according to the voltage detection data and the current detection data, simultaneously judge the line side of the distribution network When the effective value of the voltage signal reaches the set value, the effective value of the current signal on the line side of the distribution network reaches the set value, and the current on the line side of the distribution network flows to the isolation device, then the control executes the protection action; wherein, the control module The protection action is executed by controlling the disconnection of the load switch and the closure of the grounding switch on the grounding line.

In this embodiment, the voltage over-limit protection is mainly applicable to the case where the test equipment is an insulation resistance tester or an ultra-low frequency withstand voltage tester and other test equipment is not a power frequency AC signal, and the voltage can take 50Hz components or fast effective values. The current over-limit protection is mainly used to monitor the current flowing through the device. When the current exceeds the output current of the test device, it can be considered that there is a reverse power transmission situation. The current can take a 50Hz component or a fast effective value. The current direction protection is mainly used to monitor the direction of the current flowing through the device. When the current on the line side and the voltage on the line side reach their set values and at the same time it is detected that the current direction is flowing from the line side to the equipment side, it is considered that there is a reverse power transmission situation. At the same time , the current can only take 50Hz components.

At the same time, in order to improve the execution speed of the protection action, the control module can adopt an industrial-grade high-performance processor with DSP acceleration, and the fastest export time can reach 30mS.

In this embodiment, the control module is further configured to determine whether the fuse is disconnected and whether the load switch and the grounding switch are working normally according to the voltage detection data. Specifically, the control module can judge whether the fuse is disconnected according to the voltage difference between the two ends of the fuse, and judge whether the load switch and the grounding switch are connected according to the voltage difference between the two ends of the load switch and the voltage difference between the two ends of the grounding switch. Is it working properly.

Specifically, the voltage detection circuit includes: a first voltage divider, a second voltage divider, and a third voltage divider; wherein, one end of the first voltage divider is connected to the fuse and connected to the first connection one end of the second voltage divider, one end of the second voltage divider is connected to one end of the fuse connected to the static contact of the load switch, one end of the third voltage divider is connected to one end of the moving contact of the load switch, and the first The other ends of the first voltage divider, the second voltage divider and the third voltage divider are commonly grounded; the sampling ends of the first voltage divider, the second voltage divider and the third voltage divider are respectively connected to an analog-to-digital conversion module The analog input terminals of different channels of the analog-to-digital conversion module are respectively connected to the control module with the digital output terminals of corresponding channels.

The current detection circuit includes: a first current transformer; wherein, the first current transformer is arranged on the line between the first connection terminal and the second connection terminal, and the first current transformer The sampling terminal of the analog-to-digital conversion module is connected to the analog input terminal of one channel of the analog-to-digital conversion module, and the digital output terminal of the corresponding channel of the analog-to-digital conversion module is connected to the control module.

Through the above method, the voltage detection circuit and the current detection circuit can realize the monitoring of the voltage and the current on the line of multiple nodes of the first connection end and the second connection end, and convert the detected analog signal into a digital signal through the analog-to-digital conversion module , and then the control module calculates the electrical parameters such as the amplitude, frequency and phase of the current and voltage.

In this embodiment, in order to prevent testers from needing to be close to the isolation device when using related functions, the anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention is also provided with a wireless communication module; moreover, the The wireless communication module is connected to the control module, and is used to receive the control command sent by the external wireless terminal and transmit it to the control module, and transmit the status data processed by the control module to the external wireless terminal;

The control module is configured to respond to the control instruction, control the disconnection of the load switch and the closure of the grounding switch on the grounding line or select the control logic for performing a protection action. Specifically, the tester can operate the external wireless terminal and select the control logic to execute the protection action on the interface according to the type of the connected test instrument. After the selection is completed, the external wireless terminal sends the corresponding control command to the wireless communication module, and the control module passes In response to the control command, the control logic of the protection action can be executed during operation. Specifically, the control logic corresponds to voltage over-limit protection, current over-limit protection and current direction protection respectively.

In this way, the tester can not only control the isolation device through the external wireless terminal to further ensure the personal safety of the test instrument side, but also transmit the status data to the external wireless terminal to monitor the working status of the anti-reverse power transmission safety device in real time. Specifically, the wireless communication module communicates with external wireless terminals in a Lora manner, which can reduce co-channel interference and increase the reliability of wireless communication.

In this embodiment, in order to adapt to the test safety guarantee of the outdoor distribution network line, the anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention is also equipped with a battery module to provide power for the isolation device . In this way, the isolating device of the present invention can be used normally even in outdoor operation without external power supply. Specifically, the battery module uses a lithium battery and has a built-in charge and discharge management module; when in use, when the lithium battery is too low, the user can be reminded to deal with it as soon as possible through the power indicator light or sound reminder. At the same time, in order to avoid the isolation of distribution network lines and test instruments after the power of the lithium battery is exhausted, the load switch adopts normally open contacts, and the grounding switch adopts normally closed contacts.

At the same time, the anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention also includes: a state indication module; wherein, the state indication module is connected to the control module for The status data processed by the module provides corresponding status indications; wherein, the status data includes the working status data of the battery module, the load switch, the grounding switch and the fuse, and the charging status data of the equipment side and reverse power transmission status data; specifically, as shown in Figure 2, the status indication module includes: power indicator light, switch-on indicator light, ground knife indicator light, fuse fault indicator light, equipment side live indicator light, reverse transmission The electric indicator light and the electric alarm are used to check the working state of the load switch, the grounding knife switch and the fuse, as well as the live state and reverse power transmission state of the equipment side. Through the status indication, it can remind the operation and maintenance personnel to pay attention, prevent misoperation, and ensure personal and life safety.

In this embodiment, when the isolation device is in use, the high-voltage fuse is used as a backup protection. When the control module controls the disconnection of the load switch and the closing of the grounding switch, due to unexpected reasons, when the load switch fails to open and the grounding switch is successfully closed, the high-voltage The fuse will be blown to ensure the personal and life safety of the operation and maintenance personnel. In order to facilitate the replacement of the high-voltage fuse, the melting core of the high-voltage fuse is set in a replaceable manner.

In this embodiment, in order to facilitate the connection of the isolation device with the distribution network line and the test instrument, the present invention is used in the anti-reverse power transmission safety isolation device between the distribution network line and the test instrument. The first connection end and the second connection end are respectively connected with a high-voltage connection line. Specifically, the two high-voltage connecting lines are designed as quick plug-in plugs that can be connected to each other, with insulation performance ≥ 15kV and carrying capacity ≥ 1A, which can be applied to various scenarios.

The present invention provides an embodiment. The anti-reverse power transmission safety isolation device used between the distribution network line and the test instrument of the present invention includes: an outer shell, and a base arranged at the bottom of the outer shell; wherein, the The outer casing is used to accommodate the electrical part of the isolating device, and the base is an insulating and retractable structure.

Moreover, in this embodiment, the outer shell is made of insulating plastic, and since the base is made of an insulating telescopic pull rod, it not only has the function of insulation, but also can adjust the length, which is convenient for adapting to various terrains of outdoor work.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. The utility model provides a prevent reverse power transmission safety isolating device that is used for between distribution network line and the test instrument which characterized in that includes:

the first connecting end is used for connecting a power distribution network circuit;

the second connecting end is used for connecting a test instrument;

the device comprises a fuse, a load switch, a control module, a voltage detection circuit, a current detection circuit and a grounding circuit;

one end of the fuse is connected to the first connecting end, the other end of the fuse is connected to a fixed contact of the load switch, a movable contact of the load switch is connected to the second connecting end, and the second connecting end is connected with the grounding circuit;

the voltage detection circuit is used for detecting a voltage signal of at least one node between the first connecting end and the second connecting end and transmitting detected voltage detection data to the control module;

the current detection circuit is used for detecting a current signal of at least one node between the first connecting end and the second connecting end and transmitting detected current detection data to the control module;

the control module is configured to judge whether the effective value of the voltage signal on the power distribution network line side exceeds a voltage out-of-limit value or not according to the voltage detection data so as to determine whether to control to execute a protection action or not; or, according to the current detection data, judging whether the effective value of the current signal flowing through the isolation device exceeds a current out-of-limit value or not so as to determine whether to control to execute a protection action or not; or, according to the voltage detection data and the current detection data, judging that the effective value of the voltage signal at the power distribution network line side reaches a set value, the effective value of the current signal at the power distribution network line side reaches a set value and the current flow direction isolating device at the power distribution network line side simultaneously, and controlling to execute a protection action; the control module controls the load switch to be switched off and the grounding knife switch on the grounding line to be switched on so as to execute protection action.

2. The safety isolation device for preventing reverse power transmission between a power distribution network line and a test instrument as claimed in claim 1, wherein the control module is configured to determine whether the fuse is opened and whether the load switch and the grounding knife switch are working normally according to the voltage detection data.

3. An anti-reverse power transmission safety isolation device used between a power distribution network line and a test instrument as claimed in claim 2, wherein the voltage detection circuit comprises: a first voltage divider, a second voltage divider and a third voltage divider; one end of the first voltage divider is connected with one end of the fuse which is connected with the first connecting end, one end of the second voltage divider is connected with one end of the fuse which is connected with the load switch stationary contact, one end of the third voltage divider is connected with one end of the load switch movable contact, and the other ends of the first voltage divider, the second voltage divider and the third voltage divider are grounded together; sampling ends of the first voltage divider, the second voltage divider and the third voltage divider are respectively connected to analog input ends of different channels of an analog-to-digital conversion module, and digital output ends of channels corresponding to the analog-to-digital conversion module are respectively connected to the control module.

4. An anti-reverse power transmission safety isolation device used between a power distribution network line and a test instrument as claimed in claim 2, wherein the current detection circuit comprises: a first current transformer; the first current transformer is arranged on a line between the first connecting end and the second connecting end, a sampling end of the first current transformer is connected to an analog input end of one channel of the analog-to-digital conversion module, and a digital output end of the channel corresponding to the analog-to-digital conversion module is connected to the control module.

5. The safety isolation device for preventing reverse power transmission between a power distribution network line and a test instrument as claimed in any one of claims 1 to 4, further comprising: a wireless communication module; the wireless communication module is connected with the control module and used for receiving a control instruction sent by an external wireless terminal, transmitting the control instruction to the control module and transmitting state data processed by the control module to the external wireless terminal;

and the control module is used for responding to the control instruction, and controlling the load switch to be disconnected and the grounding knife switch on the grounding line to be closed or selecting the control logic for executing the protection action.

6. An anti-reverse power transmission safety isolation device used between a power distribution network line and a test instrument as claimed in claim 5, further comprising: the state indicating module and the battery module; the state indicating module is connected with the control module and used for carrying out corresponding state indication according to state data processed by the control module; the state data comprises working state data of the battery module, the load switch, the grounding disconnecting link and the fuse, and equipment side charged state data and reverse power transmission state data;

the battery module is used for providing a working power supply for the anti-reverse-power-transmission safety isolation device.

7. The safety isolation device for preventing reverse power transmission between a power distribution network line and a test instrument as claimed in claim 5, wherein the load switch is a normally open contact, and the grounding disconnecting link is a normally closed contact.

8. The safety isolation device for preventing reverse power transmission and power transmission between a power distribution network line and a test instrument as claimed in claim 5, wherein the fusible core of the high-voltage fuse is arranged in a replaceable manner.

9. The safety isolation device for preventing reverse power transmission and transmission between a power distribution network line and a test instrument as claimed in claim 5, wherein the first connection end and the second connection end are respectively connected with a high-voltage connection line.

10. An anti-reverse power transmission safety isolation device used between a power distribution network line and a test instrument according to claim 5, which comprises: the base is arranged at the bottom of the outer shell; the outer shell is used for accommodating the electrical part of the isolating device, and the base is of an insulating telescopic structure.

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