Lightning protection structure for 0.4 kV flexible voltage treatment device

Abstract

The utility model relates to a lightning protection structure for a 0.4 kV flexible voltage treatment device, and the device comprises a rectification unit, a DC line, and an inversion unit. The lightning protection structure comprises an AC lightning protection module, at least one DC lightning protection module, a lightning protection failure alarm module and a 0.4 kV flexible voltage treatment device control module. The alternating current lightning protection module is arranged on an alternating current power supply of the input rectification unit and an alternating current power supply output by the inversion unit; the lightning protection failure alarm module is used for detecting whether the alternating current lightning protection module fails or not, when the alternating current lightning protection module fails, alarm information is transmitted to the 0.4 kV flexible voltage treatment device control module, and the 0.4 kV flexible voltage treatment device control module is used for controlling opening and closing of a 0.4 kV flexible voltage treatment device; the direct current lightning protection module comprises differential mode lightning protection and common mode lightning protection. According to the utility model, the lightning protection level of a 0.4 kV flexible voltage treatment device and a low-voltage distribution line can be improved, and the adaptability to strong lightning areas such as mountainous areas and coastal areas can be improved.

Description

Technical Field

[0001] The utility model relates to a lightning protection structure for a 0.4kV flexible voltage management device, belonging to the technical field of lightning protection for flexible voltage management devices. Background Art

[0002] The fundamental cause of low voltage problems in distribution networks is the mismatch between distribution network planning and construction and load development levels. Low voltage at the end of the distribution network affects users' normal electricity consumption. Traditional low voltage management methods have problems such as long transformation cycles and low input-output ratios. Voltage management devices based on flexible DC technology have great advantages in economy, operability, and practicality, and can achieve voltage regulation of low-voltage distribution network lines. Some areas have prominent seasonal and festive load characteristics in electricity consumption, and low voltage problems still exist for users in areas with relatively weak power grid infrastructure, such as mountainous rural areas. The application of 0.4kV flexible voltage management devices can solve various low voltage problems.

[0003] 0.4kV flexible voltage management devices primarily consist of power electronic components and are susceptible to lightning-induced damage. Because low-voltage distribution lines generally have lower lightning protection levels, 0.4kV flexible voltage management devices are often damaged by lightning during use. Therefore, improving the lightning protection capabilities of flexible voltage management devices can further enhance their environmental adaptability and practicality. Utility Model Content

[0004] In order to overcome the above problems, the utility model provides a detachable electromechanical mounting rack, which has a simple structure, is easy to disassemble, has replaceable components, and is suitable for installing electromechanical equipment of different specifications.

[0005] The technical solution of the utility model is as follows:

[0006] A lightning protection structure for a 0.4kV flexible voltage management device, the 0.4kV flexible voltage management device comprising a rectifier unit, a DC line, and an inverter unit, the lightning protection structure comprising an AC lightning protection module, at least one DC lightning protection module, a lightning protection failure alarm module, and a 0.4kV flexible voltage management device control module;

[0007] The AC lightning protection module is provided on the AC power supply input to the rectifier unit and on the AC power supply output by the inverter unit;

[0008] The lightning protection failure alarm module is used to detect whether the AC lightning protection module has failed. When the AC lightning protection module fails, the alarm information is transmitted to the 0.4kV flexible voltage management device control module. The 0.4kV flexible voltage management device control module is used to control the opening and closing of the 0.4kV flexible voltage management device.

[0009] The DC lightning protection module includes differential mode lightning protection and common mode lightning protection;

[0010] The differential mode lightning protection comprises a first varistor, one end of the first varistor is connected to the positive electrode of the DC line, and the other end is connected to the negative electrode of the DC line through a first gas discharge tube;

[0011] The common-mode lightning protection includes a second varistor, one end of which is connected to the positive pole of the DC line, and the other end is connected to the negative pole of the DC line through a third varistor; the end of the second varistor not connected to the positive pole of the DC line is also grounded through a second gas discharge tube.

[0012] Furthermore, the on-state voltage of the first varistor is preset to be no less than 2 times the positive electrode voltage, and the on-state voltage threshold of the first gas discharge tube is no less than 2 times the negative electrode voltage.

[0013] Furthermore, the AC lightning protection module arranged on the three-phase AC power supply includes a fourth varistor, a fifth varistor, a sixth varistor and a seventh varistor, the fourth varistor is connected to phase A and the neutral line of the three-phase AC power supply, the fifth varistor is connected to phase B and the center line of the three-phase AC power supply, the sixth varistor is connected to phase C and the neutral line of the three-phase AC power supply, and one end of the seventh varistor is connected to the neutral line of the three-phase AC power supply, and the other end is grounded through a third gas discharge tube.

[0014] Furthermore, the AC lightning protection module arranged on the single-phase AC power supply includes an eighth varistor and a ninth varistor, the eighth varistor is connected to the phase line and neutral line of the single-phase AC power supply, and one end of the ninth varistor is connected to the neutral line of the single-phase AC power supply, and the other end is grounded through a fourth gas discharge tube.

[0015] Furthermore, the lightning protection failure alarm module includes a normally open switch, a fuse and a remote signal alarm, wherein the normally open switch and the remote signal alarm are connected in series and then in parallel with a DC power supply;

[0016] The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on;

[0017] The lightning protection failure alarm module is connected to the AC lightning protection module, and the fuse is configured to melt when the varistor of the AC lightning protection module has an overcurrent;

[0018] The normally open switch is configured to close when the fuse is blown.

[0019] Furthermore, the lightning protection failure alarm module includes a normally open switch, a plurality of fuses and a remote signal alarm, wherein the fuses are connected in parallel to form a fuse group, and the normally open switch is connected in series with the remote signal alarm and then connected in parallel with a DC power supply;

[0020] The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on;

[0021] The lightning protection failure alarm module is connected to the AC lightning protection module, the number of the fuses is the same as the number of the varistors of the AC lightning protection module, each fuse matches a different varistor, and each fuse is configured to melt when the corresponding varistor is overcurrent;

[0022] The normally open switch is configured to close when any one of the fuses is blown.

[0023] The utility model has the following beneficial effects:

[0024] (1) The proposed lightning protection structure improves the lightning protection level of the 0.4kV flexible voltage management device and the low-voltage distribution line, and adapts to the environment of strong lightning areas such as mountainous areas and coastal areas; (2) The proposed DC lightning protection module increases the DC lightning protection flow rate by paralleling the number of modules; (3) The proposed lightning protection failure alarm module monitors the effectiveness of the lightning protection module and improves the intelligent operation and maintenance level of the lightning protection structure of the 0.4kV flexible voltage management device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the module of the present utility model.

[0026] Figure 2 This is a schematic diagram of the AC lightning protection module of the utility model provided on three-phase AC power.

[0027] Figure 3 This is a schematic diagram of the AC lightning protection module of the utility model provided on single-phase AC power.

[0028] Figure 4 This is a schematic diagram of the DC lightning protection module of the present utility model.

[0029] Figure 5 This is a schematic diagram of the lightning protection failure alarm module of the present utility model. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] refer to Figure 1A lightning protection structure for a 0.4kV flexible voltage management device, the 0.4kV flexible voltage management device includes a rectifier unit, a DC line and an inverter unit, and the lightning protection structure includes an AC lightning protection module, at least one DC lightning protection module, a lightning protection failure alarm module and a 0.4kV flexible voltage management device control module;

[0032] The AC lightning protection module is provided on the AC power supply input to the rectifier unit and on the AC power supply output by the inverter unit;

[0033] The lightning protection failure alarm module is used to detect whether the AC lightning protection module has failed. When the AC lightning protection module fails, the alarm information is transmitted to the 0.4kV flexible voltage management device control module. The 0.4kV flexible voltage management device control module is used to control the opening and closing of the 0.4kV flexible voltage management device.

[0034] refer to Figure 4 , the DC lightning protection module includes differential mode lightning protection and common mode lightning protection;

[0035] The differential mode lightning protection comprises a first varistor, one end of the first varistor is connected to the positive electrode of the DC line, and the other end is connected to the negative electrode of the DC line through a first gas discharge tube;

[0036] The common-mode lightning protection includes a second varistor, one end of which is connected to the positive pole of the DC line, and the other end is connected to the negative pole of the DC line through a third varistor; the end of the second varistor not connected to the positive pole of the DC line is also grounded through a second gas discharge tube.

[0037] The AC lightning protection module is arranged on the AC side of the rectifier unit and the inverter unit. When the AC side of the rectifier unit and / or the inverter unit is affected by lightning damage, the AC lightning protection module can protect the AC line.

[0038] The DC lightning protection module is arranged on the DC line. A plurality of DC lightning protection modules can be arranged according to the length of the DC line. The plurality of DC lightning protection modules can improve the DC lightning protection flow rate and reliability.

[0039] The lightning protection failure alarm module will sound an alarm when the lightning protection fails, and control the opening and closing of the 0.4kV flexible voltage management device through the 0.4kV flexible voltage management device control module to achieve further lightning protection of the 0.4kV flexible voltage management device.

[0040] In one embodiment of the present invention, the on-state voltage of the first varistor is preset to be not less than 2 times the positive electrode voltage, and the on-state voltage threshold of the first gas discharge tube is not less than 2 times the negative electrode voltage.

[0041] The design value of the DC side operating voltage shall not exceed 2 times the rated operating voltage. If it exceeds 2 times, it is considered as overvoltage and the varistor performs conduction protection.

[0042] refer to Figure 2 In one embodiment of the utility model, the AC lightning protection module arranged on the three-phase AC power supply includes a fourth varistor, a fifth varistor, a sixth varistor and a seventh varistor, the fourth varistor is connected to the A phase and the neutral line of the three-phase AC power supply, the fifth varistor is connected to the B phase and the center line of the three-phase AC power supply, the sixth varistor is connected to the C phase and the neutral line of the three-phase AC power supply, and one end of the seventh varistor is connected to the neutral line of the three-phase AC power supply, and the other end is grounded through a third gas discharge tube.

[0043] refer to Figure 3 In one embodiment of the present utility model, the AC lightning protection module arranged on a single-phase AC power supply includes an eighth varistor and a ninth varistor, the eighth varistor is connected to the phase line and the neutral line of the single-phase AC power supply, and one end of the ninth varistor is connected to the neutral line of the single-phase AC power supply, and the other end is grounded through a fourth gas discharge tube.

[0044] refer to Figure 5 In one embodiment of the present utility model, the lightning protection failure alarm module includes a fuse and a remote signal alarm, and the fuse and the remote signal alarm are connected in series and then in parallel with a DC power supply;

[0045] The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on;

[0046] The lightning protection failure alarm module is connected to the AC lightning protection module, and the fuse is configured to melt when the varistor of the AC lightning protection module has an overcurrent.

[0047] In one embodiment of the present invention, the lightning protection failure alarm module includes a plurality of fuses and a remote signal alarm, wherein the fuses are connected in parallel to form a fuse group, and the fuse group is connected in series with the remote signal alarm and then connected in parallel with a DC power supply;

[0048] The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on;

[0049] The lightning protection failure alarm module is connected to the AC lightning protection module. The number of the fuses is the same as the number of varistors of the AC lightning protection module. Each fuse matches a different varistor, and each fuse is configured to melt when the corresponding varistor is overcurrent.

[0050] Because an AC lightning protection module includes multiple varistors, equipping each varistor with a lightning protection failure alarm module would significantly increase equipment cost and installation difficulty. To address this issue, the present invention connects several fuses in parallel, each matching a different varistor. When any fuse blows, it triggers the closure of a normally open switch, causing the remote alarm to issue an alarm signal.

[0051] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A lightning protection structure for a 0.4kV flexible voltage management device, the 0.4kV flexible voltage management device includes a rectifier unit, a DC line and an inverter unit, characterized in that: The lightning protection structure includes an AC lightning protection module, at least one DC lightning protection module, a lightning protection failure alarm module and a 0.4kV flexible voltage management device control module; The AC lightning protection module is provided on the AC power supply input to the rectifier unit and on the AC power supply output by the inverter unit; The lightning protection failure alarm module is used to detect whether the AC lightning protection module has failed. When the AC lightning protection module fails, the alarm information is transmitted to the 0.4kV flexible voltage management device control module. The 0.4kV flexible voltage management device control module is used to control the opening and closing of the 0.4kV flexible voltage management device. The DC lightning protection module includes differential mode lightning protection and common mode lightning protection; The differential mode lightning protection comprises a first varistor, one end of the first varistor is connected to the positive electrode of the DC line, and the other end is connected to the negative electrode of the DC line through a first gas discharge tube; The common-mode lightning protection includes a second varistor, one end of which is connected to the positive pole of the DC line, and the other end is connected to the negative pole of the DC line through a third varistor; the end of the second varistor not connected to the positive pole of the DC line is also grounded through a second gas discharge tube.

2. The lightning protection structure for a 0.4kV flexible voltage management device according to claim 1 is characterized in that: The on-state voltage of the first varistor is preset to be no less than 2 times the positive electrode voltage, and the on-state voltage threshold of the first gas discharge tube is no less than 2 times the negative electrode voltage.

3. The lightning protection structure for a 0.4kV flexible voltage management device according to claim 1 is characterized in that: The AC lightning protection module arranged on the three-phase AC power supply includes a fourth varistor, a fifth varistor, a sixth varistor and a seventh varistor, the fourth varistor is connected to phase A and the neutral line of the three-phase AC power supply, the fifth varistor is connected to phase B and the center line of the three-phase AC power supply, the sixth varistor is connected to phase C and the neutral line of the three-phase AC power supply, and one end of the seventh varistor is connected to the neutral line of the three-phase AC power supply, and the other end is grounded through a third gas discharge tube.

4. The lightning protection structure for a 0.4kV flexible voltage management device according to claim 1 is characterized in that: The AC lightning protection module arranged on the single-phase AC power supply includes an eighth varistor and a ninth varistor, the eighth varistor is connected to the phase line and neutral line of the single-phase AC power supply, one end of the ninth varistor is connected to the neutral line of the single-phase AC power supply, and the other end is grounded through a fourth gas discharge tube.

5. The lightning protection structure for a 0.4kV flexible voltage management device according to claim 2 or 3, characterized in that: The lightning protection failure alarm module includes a normally open switch, a fuse and a remote signal alarm. The normally open switch and the remote signal alarm are connected in series and then in parallel with a DC power supply. The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on; The lightning protection failure alarm module is connected to the AC lightning protection module, and the fuse is configured to melt when the varistor of the AC lightning protection module has an overcurrent; The normally open switch is configured to close when the fuse is blown.

6. The lightning protection structure for a 0.4kV flexible voltage management device according to claim 2 or 3, characterized in that: The lightning protection failure alarm module includes a normally open switch, a plurality of fuses and a remote signal alarm, wherein the fuses are connected in parallel to form a fuse group, and the normally open switch is connected in series with the remote signal alarm and then connected in parallel with a DC power supply; The remote signal alarm is in communication with the control module of the 0.4kV flexible voltage management device, and the remote signal alarm is configured to send an alarm signal to the 0.4kV flexible voltage management device when powered on; The lightning protection failure alarm module is connected to the AC lightning protection module, the number of the fuses is the same as the number of the varistors of the AC lightning protection module, each fuse matches a different varistor, and each fuse is configured to melt when the corresponding varistor is overcurrent; The normally open switch is configured to close when any one of the fuses is blown.

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