Isolation lightning protection device in equipotential connection and monitoring device thereof

Abstract

The invention belongs to the field of electrical equipment protection, and particularly relates to an equipotential connection isolation lightning protection device and a monitoring device thereof. The isolation lightning protection device is arranged between two devices connected through an equipotential connecting line and comprises an inductive device arranged on the equipotential connecting line and further comprises discharge units arranged at the two ends of the inductive device, the inductive device can achieve lossless passing of direct-current and low-frequency signals or currents, and the discharge units are arranged at the two ends of the inductive device. The lightning current is inhibited and isolated; and the discharge unit is used for discharging the voltage to an earth screen when the voltage on the equipotential connecting line is higher than the breakover voltage of the equipotential connecting line. Isolated lightning protection can be realized for equipotential connected equipment, and isolated lightning protection devices and important devices can be monitored.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of electrical equipment protection, and particularly relates to an isolated lightning protection device with equipotential connection and a monitoring device thereof. BACKGROUND

[0002] In order to ensure the safety of electricity use or personal safety, equipotential connection is required between different devices (see Figure 1 ). When the distance between devices is far, a situation may occur that when one device is invaded by lightning (surge), all the equipotential connected devices may be affected. For example, in the urban subway system, the rail and the door system of the platform are equipotential connected, the rail is long and leads to different platforms, and even some are outdoor, which are easy to be induced by lightning (surge), and the lightning (surge) will destroy the door system of the platform along the equipotential connection channel, causing great economic property loss and even endangering personal safety. Equipotential connection between devices is like "naked running". Figure 1 SUMMARY

[0003] In view of the lightning damage risk existing between the devices with equipotential connection, the purpose of the present application is to provide a device with isolated lightning protection mode to avoid the damage of surge current caused by lightning to the devices with equipotential connection.

[0004] To achieve the above purpose, the technical scheme adopted by the present application is an isolated lightning protection device with equipotential connection, which is arranged between two devices connected by an equipotential connection line, wherein, an inductive device is arranged on the equipotential connection line, and a discharge unit is arranged at both ends of the inductive device; the inductive device can realize the lossless passing of direct current and low-frequency signal or current and inhibit the isolated lightning current; the discharge unit is used to discharge the voltage on the equipotential connection line to the ground net when the voltage is higher than the conduction voltage of the discharge unit.

[0005] Further, the top end of one discharge unit is connected to the equipotential connection line between the first device and the inductive device, the top end of another discharge unit is connected to the equipotential connection line between the second device and the inductive device, and the tail ends of the discharge units are connected in parallel and then grounded; the discharge unit comprises a surge protector.

[0006] Further, the inductive device is a plurality of inductive devices, which are arranged in series on the equipotential connection line.

[0007] Further, one discharge unit is arranged between two adjacent inductive devices, the top end of the discharge unit is connected to the equipotential connection line between the two inductive devices, and the tail ends of the discharge unit and the tail ends of other discharge units are connected in parallel and then grounded. ​

[0008] Further, a low-pass filter unit is connected in parallel with each of the bleed units, the low-pass filter unit is used to filter the voltage of the interference signal, the top end of the low-pass filter unit is connected to the equipotential connection line and is located upstream of the bleed unit connected in parallel therewith, and the tail end of the low-pass filter unit is connected in parallel with the tail end of the bleed unit.

[0009] The application further discloses a monitoring device for the equipotential connection isolation lightning protection device, which comprises an MCU system provided with a field monitoring unit, the field monitoring unit is used to collect various data of the isolation lightning protection device, the MCU system is used to analyze and process the collected data, and the data is output and displayed through a man-machine interface and is uploaded to a cloud platform through wireless or wired communication; the man-machine interface provides hardware that can be viewed on site, current monitoring data or historical data can be viewed, and relevant parameters of the MCU system can be set; the field monitoring unit comprises an inductive device monitoring unit, a bleed unit monitoring unit, a lightning intrusion monitoring unit and an equipotential line monitoring unit.

[0010] Further,

[0011] The inductive device monitoring unit comprises a measuring current loop connected with the inductive device, and an electric resistance R1 and a signal acquisition element are arranged on the measuring current loop;

[0012] The electric resistance R1 is arranged upstream of the inductive device, and the signal acquisition element is arranged downstream of the inductive device and is grounded through the measuring current loop; or the signal acquisition element is arranged upstream of the inductive device, and the electric resistance R1 is arranged downstream of the inductive device and is grounded through the measuring current loop;

[0013] One end of the measuring current loop upstream is connected with a measuring power supply V1;

[0014] The electric resistance R1 is used for current limiting, the signal acquisition element is a sampling resistance, and the signal acquisition element can also be replaced by an input part of the inductive device;

[0015] The MCU system is connected with the signal acquisition element and reads an output signal of the signal acquisition element to judge the state of the inductive device; when the inductive device is normal, the signal acquisition element outputs a level signal, and when the inductive device is disconnected, the signal acquisition element outputs an inverted level, which is read and processed by the MCU system; or the output signal of the signal acquisition element is read by an ADC of the MCU system for processing.

[0016] Further, the discharge unit is a lightning protection device with remote signaling function, and has different state information outputs in normal and damaged states; the discharge unit monitoring unit is an IO pin of the MCU system, which is used for connecting the discharge unit and monitoring the state information of the discharge unit.

[0017] Further, the lightning intrusion monitoring unit includes a Rogowski coil arranged on the loop of each discharge unit, and the Rogowski coil is connected to the ADC pin of the MCU system through a collection circuit; when there is a surge current intrusion caused by lightning, the Rogowski coil can induce a discharged current signal, output the current signal to the collection circuit, input the ADC pin of the MCU system, and the MCU system can analyze and calculate the peak value, polarity and occurrence time of the current signal; the abnormality of the isolation lightning protection device can also be judged, and the isolation lightning protection device needs to be detected and replaced.

[0018] Further, the equipotential line monitoring unit includes a Hall sensor sleeved with the equipotential connection line, which collects the current size of the equipotential connection line, including arc or other current signals; at the same time, the voltage between the equipotential connection line and the ground net is monitored in real time.

[0019] The beneficial effects of the present application are that:

[0020] The equipotential connection device can be isolated and lightning-protected, and the isolation lightning protection device and important device can be monitored. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the device connected by equipotential in the background art of the present application;

[0022] Figure 2 is a schematic diagram of an equipotential connection isolation lightning protection device (the dashed part in the figure) described in the specific embodiment of the present application;

[0023] Figure 3 is a schematic diagram of an equipotential connection isolation lightning protection device (multi-stage isolation lightning protection form) described in the specific embodiment of the present application;

[0024] Figure 4 is a schematic diagram of the isolation lightning protection device (only one inductive device) described in the specific embodiment of the present application Figure 2 is a waveform diagram corresponding to the impulse of the residual voltage test of the isolation lightning protection device (only one inductive device) described in the specific embodiment of the present application, the discharge unit 1 end, the impulse 21kA (corresponding to the voltage 9kV);

[0025] Figure 5 is a schematic diagram of the isolation lightning protection device (only one inductive device) described in the specific embodiment of the present application Figure 2The voltage diagram displayed on the oscilloscope during the residual voltage test of the isolation surge protection device (which has only one inductive device) shows that when a current of 21kA (corresponding to a voltage of 9kV) is applied to the discharge unit 1, the residual voltage across the discharge unit 2 is only a peak voltage of 224V.

[0026] Figure 6 This is a specific embodiment of the present invention. Figure 2 A schematic diagram of the discharge current test of the isolation surge protection device (with only one inductive device) shown;

[0027] Figure 7 This is a specific embodiment of the present invention. Figure 2 The current graph displayed on the oscilloscope during the current test of the isolation surge protection device (which has only one inductive device) is shown. Channel 1 is the current of discharge unit 1 (SPD1 in the figure), channel 2 is the current of discharge unit 2 (SPD2 in the figure), and the peak value is the current through discharge unit 1.

[0028] Figure 8 This is a specific embodiment of the present invention. Figure 2 The current graph displayed on the oscilloscope during the current test of the isolation surge protection device (which has only one inductive device) is shown. Channel 1 is the current of discharge unit 1 (SPD1 in the figure), channel 2 is the current of discharge unit 2 (SPD2 in the figure), and the peak value is the current through discharge unit 2.

[0029] (Remark: Figure 7 and Figure 8 The current waveforms are the same; only the peak values ​​are measured for different objects.

[0030] Figure 9 This is a schematic diagram of a monitoring device for an equipotentially connected isolation lightning protection device according to a specific embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the inductive device monitoring unit in a specific embodiment of the present invention;

[0032] Figure 11 This is a schematic diagram of a lightning intrusion monitoring unit in a specific embodiment of the present invention;

[0033] Figure 12 This is a schematic diagram of the equipotential line monitoring unit in a specific embodiment of the present invention. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention addresses both lightning protection and monitoring, effectively protecting equipment safety.

[0035] Regarding lightning protection, this invention provides an equipotential bonding isolation lightning protection device, which is installed between two devices connected by an equipotential bonding line (see...). Figure 2 This system includes an inductive device (only one inductive device) installed on the equipotential bonding line, and a discharge unit installed across the inductive device. The inductive device allows lossless passage of DC and low-frequency (50Hz power frequency) signals or currents, and significantly suppresses and isolates lightning currents (the frequency of lightning currents is mainly distributed between 1kHz and 100kHz). The discharge unit is used to discharge voltage to the ground grid when the voltage on the equipotential bonding line is higher than its own conduction voltage. The inductive reactance of the inductive device is XL = 2πfL (f is the frequency, L is the inductance value). In a DC circuit (f = 0), the inductive reactance is zero, demonstrating the characteristic of "passing DC and blocking AC". When lightning strikes from device 1 (railway), lightning is a high-frequency signal, and the inductive device obstructs its passage, instantly accumulating high voltage at the discharge unit 1, reaching its conduction voltage, thereby dissipating the lightning's energy to the ground grid. A very small number of "slip-through" lightning strikes will be discharged through the discharge unit 2 as long as the voltage is still higher than the starting voltage of the discharge unit 2, thereby effectively preventing the intrusion of lightning (surge) and damage to equipment 2 (door system).

[0036] The top of one discharge unit is connected to the equipotential bonding line between the first device and the inductive device, and the top of another discharge unit is connected to the equipotential bonding line between the second device and the inductive device. The tail ends of the discharge units are connected in parallel and grounded. The discharge units include, but are not limited to, surge protectors (SPDs).

[0037] The isolation lightning protection device of the present invention can also be Figure 2 Based on the example shown, it can be expanded into a multi-level isolation lightning protection system (see...). Figure 3 At this time, there are several inductive devices connected in series on the equipotential bonding line. Figure 3 The example shown is of two inductive devices connected in series (this is just an example).

[0038] In a multi-level isolation lightning protection system, a discharge unit is set between two adjacent inductive devices. The top of the discharge unit is connected to the equipotential bonding line between the two inductive devices, and the tail end of the discharge unit is connected in parallel with the tail ends of other discharge units and then grounded.

[0039] In the multi-stage isolation lightning protection form, a low-pass filter unit is connected in parallel with each discharge unit, the low-pass filter unit is used to filter the voltage of the interference signal, the top end of the low-pass filter unit is connected to the equipotential connection line and is located upstream of the discharge unit connected in parallel therewith (the current first reaches the low-pass filter unit), and the tail end of the low-pass filter unit is connected in parallel with the tail end of the discharge unit; for the interference signal (including lightning signal), before the voltage of the interference signal reaches the starting voltage of the discharge unit (SPD) and during the time period when the voltage reaches the starting voltage but still needs to start, the interference signal is filtered by the filter circuit of the low-pass filter unit, when the discharge unit (SPD) starts, the discharge of the high-energy surge is completed by the discharge unit (SPD), and the voltage is clamped in the set range; and a plurality of inductive devices are connected in series, and a plurality of low-pass filter units and discharge units are connected in parallel to achieve the purpose of lightning protection.

[0040] Based on Figure 2 The isolation lightning protection device (only one inductive device) shown in the drawing achieves good lightning protection effect in the simulation lightning impact test (residual voltage test and current test), and the specific effect is as follows:

[0041] Selection of discharge unit in simulation lightning impact test:

[0042] SPD1 (discharge unit 1): In=20kA, Imax=40kA, maximum continuous working voltage Uc=100V, SPD2 (discharge unit 2): In=20kA, Imax=40kA, maximum continuous working voltage Uc=100V.

[0043] 1. Residual voltage test:

[0044] In Figure 2 the dotted line part of the discharge unit 1, when the current of 21kA (corresponding to the voltage of 9kV) is impacted (as shown in Figure 4 ), the voltage between the two ends of the discharge unit 2 is only the peak voltage of 224V (as shown in Figure 5 ), which is the residual voltage, and the protected equipment is safe.

[0045] 2. Current test:

[0046] As shown in Figure 6 , the current discharge conditions during the simulation lightning are measured at the discharge unit 1 and the discharge unit 2 respectively. As can be seen from Figure 7 , Figure 8 , the starting time of SPD1 (discharge unit 1) is about 5uS earlier than that of SPD2 (discharge unit 2), the current through SPD1 (discharge unit 1) is about 21.8kA (see Figure 7 ), and the current through SPD2 (discharge unit 2) is only 400A (see Figure 8), more than 98% of lightning current is discharged from the SPD in front of the inductive device (arrester), effectively protecting the equipment in the rear.

[0047] In the monitoring aspect, the application also discloses a monitoring device for the equipotential bonding isolation lightning protection device (see Figure 9 ), which comprises an MCU system provided with a field monitoring unit, the field monitoring unit is used for collecting various data of the isolation lightning protection device, the MCU system is used for analyzing and processing the collected data, and the data is output and displayed through a man-machine interface, and the data is uploaded to a cloud platform through wireless or wired communication, so that the user can control the running state of the lightning protection device in real time, and the damaged lightning protection device can be replaced in the first time, and the safety of the equipment is better protected; the man-machine interface provides hardware that can be viewed on site, the current monitoring data or historical data can be viewed, and the related parameters of the MCU system can be set; the field monitoring unit comprises an inductive device monitoring unit, a discharge unit monitoring unit, a lightning intrusion monitoring unit and an equipotential line monitoring unit.

[0048] The inductive device monitoring unit (see Figure 10 ) comprises a measuring current loop connected with the inductive device (for passing through direct current or low-frequency alternating current signal), and an electric resistance R1 and a signal collecting element are arranged on the measuring current loop;

[0049] The electric resistance R1 is arranged upstream of the inductive device, and the signal collecting element is arranged downstream of the inductive device and grounded through the measuring current loop; or the signal collecting element is arranged upstream of the inductive device, and the electric resistance R1 is arranged downstream of the inductive device and grounded through the measuring current loop;

[0050] One end of the measuring current loop upstream is connected with a measuring power supply V1;

[0051] The electric resistance R1 is used for current limiting; the signal collecting element is a sampling resistance or other elements capable of collecting signals, and the signal collecting element can also be replaced by an input part of the inductive device;

[0052] The MCU system is connected with the signal collecting element and reads the output signal of the signal collecting element to judge the state of the inductive device; since the inductive device (isolation arrester) is in a straight-through state to low-frequency or direct current signal, when the inductive device is normal, the signal collecting element outputs a level signal, if the inductive device is disconnected (disconnected to the ground, that is, the inductive device is not normal), the signal collecting element outputs an inverted level, and the output is read and processed by the MCU system; or the output signal of the signal collecting element is read by the ADC of the MCU system for processing.

[0053] The discharge unit is a lightning protection device with remote signaling function, and has different state information outputs, i.e., different switch outputs, under normal and damaged conditions; the discharge unit monitoring unit is an IO pin of the MCU system, which is used to connect the discharge unit and monitor the state information of the discharge unit, i.e., the MCU system only needs to use one IO pin to detect the switch output of the discharge unit.

[0054] The lightning intrusion monitoring unit (see Figure 11 ) includes a Rogowski coil arranged on the loop of each discharge unit, and the Rogowski coil is connected to the ADC pin of the MCU system through a collection circuit; when there is a surge current caused by lightning intrusion, and the voltage is greater than the starting voltage of the discharge unit (SPD), the surge current is discharged to the ground by the isolation lightning protection device, the Rogowski coil can sense the discharged current signal, and output the current signal to the collection circuit, after processing such as voltage division and filtering, the current signal is input to the ADC pin of the MCU system, and the MCU system analyzes and calculates the peak value, polarity and occurrence time of the current signal; from the cloud platform or the man-machine interface (local display), it can be seen that under normal conditions, the lightning surge current signal of the front-stage discharge unit is much larger than that of the rear-stage discharge unit, otherwise, it can be judged that the isolation lightning protection device is abnormal and needs to be detected and replaced.

[0055] The equipotential line monitoring unit (see Figure 12 ) includes a Hall (current) sensor sleeved on the equipotential connection line, which collects the current size of the equipotential connection line, including arc or other current signals; at the same time, the voltage between the equipotential connection line and the ground net is monitored in real time; the passing current and the voltage to the ground of the equipotential connection line are monitored in real time, so as to provide the running state of the connection line for the user to make corresponding treatment.

[0056] The device described in the application is not limited to the embodiments described in the specific embodiments, and other embodiments can be derived by those skilled in the art according to the technical solutions of the application, which also belong to the technical innovation range of the application.

Claims

1. An equipotential bonding isolation surge protection device, installed between two devices connected by an equipotential bonding line, characterized in that: The device comprises an inductive device arranged on the equipotential bonding wire, and a leakage unit arranged at both ends of the inductive device, the inductive device being capable of realizing lossless passing of direct current and low-frequency signal or current and inhibiting lightning current isolation; the leakage unit is used to discharge the voltage on the equipotential bonding wire to the ground net when the voltage is higher than the conduction voltage of the leakage unit.

2. An equipotential bonding isolation lightning protection device according to claim 1, characterised in that: The top end of one of the leakage units is connected to the equipotential bonding wire between the first device and the inductive device, and the top end of the other leakage unit is connected to the equipotential bonding wire between the second device and the inductive device, and the tail ends of the leakage units are connected in parallel and grounded; the leakage unit comprises a surge protector.

3. An equipotential bonding isolation lightning protection device according to claim 2, characterised in that: The inductive device is arranged in series on the equipotential bonding wire.

4. An equipotential bonding isolation lightning protection device according to claim 3, characterised in that: The leakage unit is arranged between two adjacent inductive devices, the top end of the leakage unit is connected to the equipotential bonding wire between the two inductive devices, and the tail end of the leakage unit is connected in parallel with the tail ends of other leakage units and grounded.

5. The equipotential bonding isolation surge protection device as described in claim 4, characterized in that: in A low-pass filter unit is connected in parallel with each leakage unit, the low-pass filter unit is used to filter the voltage of interference signal, the top end of the low-pass filter unit is connected to the equipotential bonding wire and located upstream of the leakage unit connected in parallel thereto, and the tail end of the low-pass filter unit is connected in parallel with the tail end of the leakage unit.

6. A monitoring device for an equipotential bonding isolation lightning protection device as claimed in claim 5, characterized in that: The device comprises an MCU system provided with a field monitoring unit, the field monitoring unit is used to collect various data of the lightning protection device, the MCU system is used to analyze and process the collected data, and the data is output and displayed through a man-machine interface, and the data is uploaded to a cloud platform through wireless or wired communication; the man-machine interface provides hardware that can be viewed on site, current monitoring data or historical data can be viewed, and related parameters of the MCU system can be set; the field monitoring unit comprises an inductive device monitoring unit, a leakage unit monitoring unit, a lightning intrusion monitoring unit and an equipotential line monitoring unit.

7. The monitoring device of claim 6, wherein: The inductive device monitoring unit comprises a measuring current loop connected to the inductive device, and a resistor R1 and a signal acquisition element are arranged on the measuring current loop; The resistor R1 is arranged upstream of the inductive device, and the signal acquisition element is arranged downstream of the inductive device and grounded through the measuring current loop; or, the signal acquisition element is arranged upstream of the inductive device, and the resistor R1 is arranged downstream of the inductive device and grounded through the measuring current loop; One end of the measuring current loop upstream is connected to a measuring power supply V1; The resistor R1 is used for current limiting; the signal acquisition element is a sampling resistor, and the signal acquisition element can also be replaced by an input part of the inductive device; The MCU system is connected to the signal acquisition element and reads the output signal of the signal acquisition element to determine the state of the inductive device. When the inductive device is normal, the signal acquisition element outputs a level signal, and if the inductive device is disconnected, the signal acquisition element outputs an inverse level, which is output to the MCU system for reading and processing; or the output signal of the signal acquisition element is read by the ADC of the MCU system for processing.

8. The monitoring device of claim 6, wherein: The discharge unit is a lightning protection device with remote signaling function, and has different state information outputs in normal and damaged states; the discharge unit monitoring unit is an IO pin of the MCU system, which is used for connecting the discharge unit and monitoring the state information of the discharge unit.

9. The monitoring device of claim 6, wherein: The lightning intrusion monitoring unit includes a Rogowski coil arranged on the loop of each discharge unit, and the Rogowski coil is connected to the ADC pin of the MCU system through an acquisition circuit; when there is a surge current intrusion caused by lightning, the Rogowski coil can induce a discharged current signal, and output the current signal to the acquisition circuit and input the ADC pin of the MCU system, and the MCU system can analyze and calculate the peak value, polarity and occurrence time of the current signal; the abnormality of the isolation lightning protection device can also be judged from the current signal, and the isolation lightning protection device needs to be detected and replaced.

10. The monitoring device of claim 6, wherein: The equipotential line monitoring unit includes a Hall sensor sleeved on the equipotential connection line, which acquires the current size of the equipotential connection line, including arc or other current signals; at the same time, the voltage between the equipotential connection line and the ground net is monitored in real time.

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