Surge protectors and surge protection systems

Abstract

The present invention provides a surge protector and a surge protection system, the surge protector further comprising: a switch module, a transformer module and a detection drive module, the switch module is provided with a shunt tripping device, the switch module is connected in series to the front end of the line where the varistor group is located, and the transformer module is connected to the lightning protection module; the detection drive module is connected to the switch module and the transformer module respectively, and is used to receive the current signal sensed by the transformer module, and when it is detected that the current magnitude of the current signal exceeds the set current threshold, and the duration of the current signal exceeds the set time threshold, the shunt tripping device is driven to drive the switch module to disconnect the line. The surge protector and the surge protection system of the present invention can accurately and timely disconnect the internal circuit of the surge protector when a large current occurs and the duration is long, thereby improving the reliability and safety of the surge protector, and has a simple structure and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of surge protection, and in particular to a surge protector and a surge protection system. Background Art

[0002] Surge protectors are indispensable equipment in low-voltage power distribution systems. At present, in low-voltage power distribution environments, voltage-limiting surge protectors are the most commonly used, which use varistors with advantages such as fast response, low residual voltage, and strong impact resistance as lightning protection components. At the same time, due to the defects of varistors such as easy degradation, unstable degradation state, and discontinuous resistance change, after several lightning strikes or surge shocks, the varistors degrade, causing leakage current and heat generation; or when there is a power frequency short-circuit current in the line, the varistors are heated due to conduction, which can easily cause fire and other dangers.

[0003] Generally, the prior art solves the above problem in the following two ways: one is to install a thermal trip device based on the principle that low-temperature solder melts when encountering high temperature at the pin of the varistor. When the varistor heats up, the temperature is transmitted to the low-temperature solder point, and the solder melts to activate the trip mechanism connected to the solder point, thereby disconnecting the varistor path and putting the line out of danger; the other is to connect a circuit protection device (such as a circuit breaker or a fuse) in series on the path where the surge protector is located. When a short-circuit current appears in the path, the circuit protection device is activated to cut off the path and put the line out of danger.

[0004] However, the inventors found that the prior art has the following defects: First, in the first method mentioned above, the action of the thermal tripping device is based on the response of the low-temperature solder to the temperature. The low-temperature solder is easily affected by the environment and its melting point is very unstable. At the same time, it is subject to the constraints of the welding process, and it is easy to cause the tripping mechanism to be unable to be disengaged due to solder adhesion and wire drawing. Secondly, in the second method mentioned above, taking the circuit breaker as an example, the circuit breaker needs to meet the requirements of not acting when the impact of lightning current or surge current (kA level) comes, and acting immediately when the power frequency short-circuit current (A level) comes. Since the contact mechanism inside the circuit breaker will be repelled by the Lorentz force when a strong surge current flows through, this requirement is difficult to meet; in addition, due to the unstable degradation state of the varistor, the short-circuit current in the line ranges from a few amperes to hundreds of amperes, and it is difficult for the circuit protection device to accurately and timely act when any short-circuit current value passes, making the reliability and safety of the surge protector low. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a surge protector and a surge protection system to accurately and timely disconnect the internal circuit of the surge protector when a large current occurs and lasts for a long time, thereby improving the reliability and safety of the surge protector, and the structure is simple and the cost is low.

[0006] To achieve the above-mentioned purpose of the invention, an embodiment of the present invention provides a surge protector, including a lightning protection module, the lightning protection module including a varistor group composed of a plurality of varistors, the surge protector also including: a switch module, a transformer module and a detection and driving module, the switch module is provided with a shunt tripping device, the switch module is connected in series to the front end of the line where the varistor group is located, and the transformer module is connected to the lightning protection module; the detection and driving module is respectively connected to the switch module and the transformer module, and is used to receive the current signal sensed by the transformer module, and when it is detected that the current magnitude of the current signal exceeds a set current threshold and the duration of the current signal exceeds a set time threshold, drives the shunt tripping device to drive the switch module to disconnect the line.

[0007] Preferably, the switch module comprises a plurality of switches, the number of the switches is the same as the number of the varistors, and the switches are connected in a one-to-one correspondence.

[0008] Preferably, the shunt tripping device comprises a shunt tripper connected to the detection and driving module.

[0009] Preferably, the mutual inductor module includes a current sensor connected to the detection and driving module, and the current sensor is connected to the lightning protection module via a PE terminal.

[0010] Preferably, the shunt tripping device comprises a plurality of shunt releases respectively connected to the detection and driving modules, and the number of the shunt releases is the same as the number of the switches and are arranged in a one-to-one correspondence.

[0011] Preferably, the transformer module includes a plurality of current sensors respectively connected to the detection drive modules, the number of the current sensors is the same as the number of the varistors, and they are arranged in one-to-one correspondence, and the plurality of current sensors are respectively connected between corresponding varistors and PE terminals.

[0012] Preferably, the detection and driving module includes a detection unit, a computing unit, a storage unit, a driving unit and a communication unit;

[0013] The detection unit is connected to the operation unit, and is used to receive the current signal sensed by the transformer module, detect the current magnitude and duration of the current signal, and send the detected current magnitude and duration to the operation unit;

[0014] The computing unit is connected to the storage unit and the driving unit respectively, and is used to determine the current type according to the current magnitude and duration, and when the determined current type is a lightning current or a surge current, send first information used to characterize the current type as a lightning current or a surge current to the storage unit, or when the determined current type is a leakage current or a power frequency short-circuit current, send second information used to characterize the current type as a leakage current or a power frequency short-circuit current to the driving unit;

[0015] The storage unit is used to record the number of lightning strikes and / or surge impacts;

[0016] The driving unit is used to drive the shunt tripping device;

[0017] The communication unit is connected to the operation unit, the storage unit and the drive unit respectively, and sends a message characterizing the occurrence of at least one of lightning current, surge current, leakage current and power frequency short-circuit current to the monitoring host; and / or sends the recorded number of lightning strikes and surge impacts to the monitoring host; and / or receives an instruction sent by the monitoring host to instruct the action of the driving shunt trip device.

[0018] An embodiment of the present invention further provides a surge protection system, comprising at least one surge protector as described in the above embodiment, a data acquisition device and a monitoring host, wherein the surge protector and the monitoring host are respectively communicatively connected to the data acquisition device.

[0019] The surge protector and surge protection system provided by the embodiments of the present invention detect the current signal sensed by the mutual inductor module, and the current magnitude and duration of the current signal are detected by the detection driving module. When the current magnitude and duration both exceed the corresponding threshold values, the shunt tripping device is driven to drive the switch module to operate, thereby achieving the ability to accurately and timely disconnect the internal circuit of the surge protector when a large current occurs and lasts for a long time, thereby improving the reliability and safety of the surge protector, and the structure is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the surge protector according to the first embodiment of the present invention; for ease of understanding, the figure shows the phase line terminal and the neutral line terminal;

[0021] Figure 2 This is a structural block diagram of a detection and driving module in a surge protector according to Embodiment 1 of the present invention;

[0022] Figure 3 Schematic diagram of the structure of the surge protector of the second embodiment of the present invention; for easy understanding, the figure shows the phase line terminal, the neutral line terminal, and the PE terminal;

[0023] Figure 4 Schematic diagram of the structure of the surge protector of the third embodiment of the present invention; for easy understanding, the figure shows the phase line terminal, the neutral line terminal, and the PE terminal;

[0024] Figure 5 This is a structural block diagram of a surge protection system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0025] The surge protector and the surge protection system according to the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] Embodiment 1

[0027] Figure 1 FIG. 1 is a schematic diagram of the structure of a surge protector according to Embodiment 1 of the present invention, referring to FIG. Figure 1 The surge protector includes a lightning protection module 110, a switch module 120, a mutual inductor module 130 and a detection and driving module 140. Among them, the lightning protection module includes a varistor group 111 composed of a plurality of varistors. A shunt tripping device 150 is provided on the switch module 120, the switch module 120 is connected in series to the front end of the line where the varistor group 111 is located, and the mutual inductor module 130 is connected to the lightning protection module 110; the detection and driving module 140 is respectively connected to the switch module 120 and the mutual inductor module 130, and is used to receive the current signal sensed by the mutual inductor module 130, and when it is detected that the current magnitude of the current signal exceeds the set current threshold value, and the duration of the current signal exceeds the set time threshold value, the shunt tripping device 150 is driven to drive the switch module 120 to disconnect the line.

[0028] In actual application, a switch module 120 with a shunt trip device 150 is connected in series at the front end of the varistor group 111, a transformer module 130 is installed on the grounding wire, and the detection drive module 140 is connected to the transformer module 130. The transformer module 130 detects the current condition entering the ground. For example, when the current exceeds the milliampere (mA) level and the duration exceeds the millisecond (ms) level, the detection drive module 140 drives the shunt trip device 150 to disconnect the switch module 120, thereby cutting off the circuit. Therefore, regardless of leakage current or power frequency short-circuit current, as long as it exceeds the preset current threshold value and duration threshold value at the same time, the detection drive module 140 will drive the shunt trip device 150 to drive the switch module 120 to operate. In addition, Figure 1 A varistor group consisting of four varistors is illustrated, but is not limited to this. The present application does not specifically limit the number of varistors.

[0029] The lightning protection module 110 may specifically include a housing, on which a phase line (such as Figure 1 L1, L2 and L3 as shown), neutral line (such as Figure 1The N shown in the figure) and the connection terminal of the ground wire are provided with a varistor inside, and the inside is filled with potting material, so that the lightning protection module has moisture-proof and corrosion-resistant properties and can be used normally in any environment. Therefore, the lightning protection module is only composed of a shell, a filling material and a varistor, and a terminal arranged on the shell, so that the lightning protection function can be realized with the simplest structure, and the production cost of the lightning protection module can also be reduced.

[0030] Figure 2 This is a structural block diagram of the detection and driving module in the surge protector of the first embodiment of the present invention, referring to Figure 2 Further, the detection and driving module 140 may specifically include a detection unit 210 , a computing unit 220 , a storage unit 230 , a driving unit 240 and a communication unit 250 .

[0031] The detection unit 210 is connected to the operation unit 220 , and is used to receive the current signal sensed by the transformer module 130 , detect the current magnitude and duration of the current signal, and send the detected current magnitude and duration to the operation unit 220 .

[0032] The operation unit 220 is respectively connected to the storage unit 230 and the driving unit 240, and is used to determine the current type according to the current size and duration. When the determined current type is a lightning current or a surge current, the first information used to characterize the current type as a lightning current or a surge current is sent to the storage unit 230, or, when the determined current type is a leakage current or a power frequency short-circuit current, the second information used to characterize the current type as a leakage current or a power frequency short-circuit current is sent to the driving unit 240.

[0033] The storage unit 230 is used to record the number of lightning strikes and / or the number of surge impacts.

[0034] The driving unit 240 is used to drive the shunt tripping device.

[0035] The communication unit 250 is connected to the operation unit 220, the storage unit 230 and the drive unit 240 respectively, and sends a message characterizing the occurrence of at least one of lightning current, surge current, leakage current and power frequency short-circuit current to the monitoring host; and / or sends the recorded number of lightning strikes and surge impacts to the monitoring host; and / or receives an instruction sent by the monitoring host to instruct the drive shunt trip device to operate.

[0036] In this way, it is possible to ensure the normal discharge of lightning strikes or surge currents, and to disconnect them in time when leakage current or power frequency short-circuit current occurs. Assuming that the current value of the lightning current or surge current is large at this time, but the duration is at the μs level, it obviously does not meet the condition that the duration exceeds the threshold value, and the drive unit 240 will not drive the shunt trip device 150 to drive the switch module 120 to operate, so as to ensure the normal discharge of the lightning current or surge. In addition, the detection drive module 140 may also include a power supply for powering it.

[0037] In the system application, the communication unit 250 is connected to the operation unit 220, and the event of lightning current (or surge current) or leakage current (or power frequency short-circuit current) can be notified to the monitoring host through the data collector. The communication unit 250 is connected to the storage unit 230, so that the monitoring host can connect to the communication unit 250 through the data collector to query the data of the number of lightning strikes and / or surge impacts recorded in the storage unit 230. The communication unit 250 is connected to the drive unit 240, so that the monitoring host can connect to the communication unit 250 through the data collector and send instructions to the drive unit 240 to activate the shunt trip device 150.

[0038] The surge protector provided in the embodiment of the present invention detects the current signal sensed by the mutual inductor module, and the current magnitude and duration of the current signal are detected by the detection driving module. When the current magnitude and duration both exceed the corresponding threshold values, the shunt tripping device is driven to drive the switch module to operate, thereby achieving the ability to accurately and timely disconnect the internal circuit of the surge protector when a large current occurs and lasts for a long time, thereby improving the reliability and safety of the surge protector, and the structure is simple and the cost is low.

[0039] In addition, this embodiment also has the following effects: by detecting that the detection unit, the drive unit, the operation unit, the communication unit and the storage unit in the drive module cooperate with each other, when the current magnitude and the duration of the received current signal exceed the corresponding threshold values, the shunt tripping device can be driven to drive the switch module to operate, and the number of lightning strikes can also be stored.

[0040] Embodiment 2

[0041] Figure 3 FIG. 1 is a schematic diagram of the structure of a surge protector according to the second embodiment of the present invention. Figure 1 A specific implementation of the device embodiment shown in FIG. Figure 3 ,compared to Figure 1 The device structure of the device embodiment shown, Figure 3 Detailed structures of the switch module 120 , the shunt trip device 150 and the transformer module 130 are shown in FIG.

[0042] Specifically, the switch module 120 may include a plurality of switches 310 , the number of the switches 310 being the same as the number of the varistors, and being connected in a one-to-one correspondence.

[0043] Furthermore, the shunt trip device 150 may include a shunt tripper 320 connected to the detection and driving module 140 .

[0044] In a specific implementation, the switch 310 in the switch module 120 can be a simple switch structure, that is, a pure mechanical switch, and the shunt release 320 can be a pure mechanical linkage device without any electromagnetic components, so as to ensure the impact resistance to lightning current or surge current, and the resistance of the switch itself is very small, ensuring that the residual pressure is very low when the current is passed. In addition, in actual applications, the switch module 120 can also include an arc extinguishing device to ensure that no arc occurs when the switch is actuated.

[0045] Furthermore, the transformer module 130 may include a current sensor 330 connected to the detection and driving module 140 , and the current sensor 330 is connected to the lightning protection module 110 via a PE terminal.

[0046] This embodiment takes a three-phase surge protector as an example. Figure 3 L1, L2, and L3 are shown as phase lines, N is a neutral line, and PE is a ground line. The current sensor 330 is installed on the main ground line to detect the total current signal. When the detection drive module 140 detects that the magnitude and duration of the total ground current sensed by the current sensor 330 exceed the threshold value at the same time, the shunt release 320 is driven to drive the multiple switches 310 in the switch module to operate, disconnect the lines where the multiple varistors are located, so that the lightning protection module 110 is completely disconnected. Therefore, the lightning protection module can be replaced as a whole during maintenance.

[0047] The surge protector provided by the embodiment of the present invention accurately and quickly senses the total current signal through the current sensor installed on the main grounding line. When the detection driving module connected to the current sensor detects that the current magnitude and duration of the total current signal simultaneously exceed the threshold value, the shunt release is driven to drive multiple switches in the switch module to operate, disconnect the lines where the multiple varistors are located, so that all the lightning protection modules are disconnected, thereby improving the reliability and safety of the surge protector, and the structure is simple and the cost is low. In addition, the switch module is composed of a simple switch, and a shunt release is provided, which further reduces the cost and improves the reliability.

[0048] Embodiment 3

[0049] Figure 4 FIG. 1 is a schematic diagram of the structure of a surge protector according to Embodiment 3 of the present invention. Figure 1 Another specific implementation of the device embodiment shown is shown in FIG. Figure 4 ,compared to Figure 3 The device structure of the device embodiment shown, Figure 4 It is shown in Figure 3 The specific structures of different shunt trip devices 150 and the specific structures of the transformer module 130 .

[0050] Specifically, the shunt tripping device 150 includes a plurality of shunt trippers 320 respectively connected to the detection and driving modules 140 . The number of the shunt trippers 320 is the same as the number of the switches 310 , and they are arranged in a one-to-one correspondence.

[0051] Furthermore, the transformer module 130 includes a plurality of current sensors 330 respectively connected to the detection drive module 140. The number of the current sensors 330 is the same as the number of the varistors and they are arranged in one-to-one correspondence. The plurality of current sensors 330 are respectively connected between the corresponding varistors and the PE terminals.

[0052] That is to say, each switch 310 on each line has a shunt release 320, and the detection drive module 140 is connected to four shunt releases 320 respectively. At the same time, each line is provided with a current sensor 330, and the current sensor 330 on each line only detects the current condition on the corresponding line.

[0053] In practical applications, the lightning protection module 110 in this embodiment can be divided into the following Figure 4 The four independent submodules within the dashed box are no longer a whole. When the switch 310 is actuated, only the submodules on the corresponding circuits need to be replaced without replacing all of them.

[0054] The surge protector provided in the embodiment of the present invention is provided with a shunt release for the switch on the line where each varistor is located, and a current sensor is provided on each line. The current sensor on each line only detects the current situation on the line. Multiple current sensors are respectively connected to the detection drive module, and the detection drive module is respectively connected to multiple shunt releases, so that the current size and duration of the current signal of each line can be independently detected. At the same time, when a large current appears in a certain line or several lines and the duration is long, the corresponding line is disconnected accurately and timely. Compared with the aforementioned embodiment 2, the surge protector with this structure makes the surge protection operation more flexible, without disconnecting all lines, avoiding unnecessary waste of resources.

[0055] Embodiment 4

[0056] Figure 5This is a structural block diagram of a surge protection system according to Embodiment 4 of the present invention, and the surge protection system includes a main monitoring station 540, at least one sub-monitoring station 530, at least one data acquisition device 520, and at least one surge protector 510 as described in any one of Embodiments 1, 2, and 3 above. At least one sub-monitoring station 530 is communicatively connected to the main monitoring station 540, at least one data acquisition device 520 is communicatively connected to the corresponding at least one sub-monitoring station 530, and at least one surge protector 510 is communicatively connected to the corresponding at least one data acquisition device 520.

[0057] In a specific implementation, a monitoring host is set in the main monitoring station 540, and a monitoring host is also set in each sub-monitoring station 530. In addition, in actual applications, the sub-monitoring station can also connect multiple data acquisition devices through network devices such as switches, so that more surge protectors can be reasonably managed in different regions in such a large application environment.

[0058] The detection and driving module in the surge protector 510 is connected to the data acquisition device 520, and the data acquisition device 520 is connected to the monitoring host of the main monitoring station 540 through the sub-monitoring station 530. When the detection and driving module drives the shunt release to act, it will send data information for reporting the tripping event to the data acquisition device 520, for example, using a switch signal (0 or 1) as the data information, and the preset "1" represents the occurrence of a tripping event. When the monitoring host of the main monitoring station 540 receives "1", the accident can be discovered. At the same time, the surge protector 510 stores the number of lightning strikes and records lightning strikes, so the monitoring host of the main monitoring station 540 can also query the relevant lightning strike situation. In addition, the monitoring host of the main monitoring station 540 can also issue a command to one or more surge protectors 510 at any time to control the shunt release device to drive the switch module to act to disconnect the internal circuit. Each sub-monitoring station 530 can view the information of multiple surge protectors 510 connected to it, and perform switch control on these multiple surge protectors 510.

[0059] The surge protection system provided by the embodiment of the present invention realizes convenient and rapid collection of the number of lightning strikes stored in the surge protector and the recorded lightning strike time through the system architecture composed of the main monitoring station, the sub-monitoring station, the data acquisition device and the surge protector, and the communication connection established between them, and the data transmission is more secure. In addition, the collected data can also be transmitted to the main monitoring station. At the same time, the main monitoring station can also actively send a command to one or several surge protectors to control the shunt trip device to drive the switch module to operate. Thereby providing a convenient channel for big data analysis and surge protector management.

[0060] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A surge protector, comprising a lightning protection module, wherein the lightning protection module comprises a housing and a varistor group composed of a plurality of varistors arranged in the housing, characterized in that: The surge protector further comprises: a switch module, a mutual inductor module and a detection drive module, wherein the switch module is provided with a shunt tripping device, the switch module is connected in series to the front end of the line where the varistor group is located, and the mutual inductor module is connected to the lightning protection module; The detection drive module is connected to the switch module and the transformer module respectively, and is used to receive the current signal sensed by the transformer module, and when it is detected that the current magnitude of the current signal exceeds the set current threshold and the duration of the current signal exceeds the set time threshold, drive the shunt trip device to drive the switch module to disconnect the line. The detection drive module includes a detection unit, a calculation unit and a drive unit, wherein: The detection unit is connected to the operation unit, and is used to receive the current signal sensed by the transformer module, detect the current magnitude and duration of the current signal, and send the detected current magnitude and duration to the operation unit; The operation unit is connected to the driving unit, and is used to send second information used to characterize that the current type is leakage current or power frequency short-circuit current to the driving unit when the determined current type is leakage current or power frequency short-circuit current; The driving unit is used for driving the shunt tripping device.

2. The surge protector according to claim 1, characterized in that: The switch module includes a plurality of switches, the number of the switches is the same as the number of the varistors, and the switches are connected in a one-to-one correspondence.

3. The surge protector according to claim 2, characterized in that: The shunt tripping device comprises a shunt tripper connected to the detection and driving module.

4. The surge protector according to claim 3, characterized in that: The mutual inductor module includes a current sensor connected to the detection and driving module, and the current sensor is connected to the lightning protection module via a PE terminal.

5. The surge protector according to claim 2, characterized in that: The shunt tripping device comprises a plurality of shunt releases respectively connected to the detection and driving modules. The number of the shunt releases is the same as the number of the switches and they are arranged in a one-to-one correspondence.

6. The surge protector according to claim 5, characterized in that: The mutual inductor module includes a plurality of current sensors respectively connected to the detection drive modules, the number of the current sensors is the same as the number of the varistors, and they are arranged in one-to-one correspondence, and the plurality of current sensors are respectively connected between corresponding varistors and PE terminals.

7. The surge protector according to claim 2, characterized in that: The switch is a mechanical switch.

8. The surge protector according to claim 3 or 5, characterized in that: The shunt release is a mechanical linkage device.

9. The surge protector according to any one of claims 1 to 7, characterized in that: The detection and driving module also includes a storage unit and a communication unit; The computing unit is also connected to the storage unit, and is further used to determine the current type according to the current magnitude and duration, and when the determined current type is a lightning current or a surge current, send first information used to characterize that the current type is a lightning current or a surge current to the storage unit; The storage unit is used to record the number of lightning strikes and / or surge impacts; The communication unit is connected to the operation unit, the storage unit and the drive unit respectively, and sends a message characterizing the occurrence of at least one of lightning current, surge current, leakage current and power frequency short-circuit current to the monitoring host; and / or sends the recorded number of lightning strikes and surge impacts to the monitoring host; and / or receives an instruction sent by the monitoring host to instruct the action of the driving shunt trip device.

10. A surge protection system, characterized in that: It comprises a main monitoring station, at least one sub-monitoring station, at least one data acquisition device and at least one surge protector as described in any one of claims 1 to 9, wherein the at least one sub-monitoring station is communicatively connected to the main monitoring station, the at least one data acquisition device is communicatively connected to the corresponding at least one sub-monitoring station, and the at least one surge protector is communicatively connected to the corresponding at least one data acquisition device.

Images