CN102931592A - Lightning-protection power distribution cabinet - Google Patents

Abstract

The present application discloses a lightning protection power distribution cabinet, which includes a cabinet body and a lightning protection power supply circuit. The lightning protection power supply circuit includes: a lightning protection circuit, an indicating device and an output unit, wherein the input terminal of the lightning protection circuit The power system is connected, and the output end of the lightning protection circuit is connected to the output unit, which is used to eliminate the lightning surge voltage entering from the power system; the lightning protection circuit includes first-stage discharge units connected in sequence , the second-level current blocking unit and the third-level clamping unit; the indicating device is connected to the lightning protection circuit for displaying the current and voltage of each phase in the lightning protection circuit; the output unit’s The output end is connected with the equipment to be protected, and is used for supplying power to the equipment to be protected. The lightning protection power distribution cabinet uses the lightning protection power supply path set in the cabinet to eliminate the lightning surge voltage entering from the power system in three stages, thereby preventing the lightning surge voltage from being damaged by the power system to the protection equipment.

Description

Lightning protection distribution cabinet

technical field

The present application relates to the technical field of circuit protection, in particular to a lightning protection distribution cabinet.

Background technique

With the advancement of science and technology, the automation system composed of microcomputers and large-scale integrated circuit devices replaces conventional measuring and monitoring instruments, conventional control panels, central signal systems, remote control panels and conventional relay protection. Improve the level of automation and intelligence.

However, the ensuing problem is that for the integrated circuit of the microcomputer system, the operating voltage is only a few volts, and the signal current is only in the microampere level. Compared with the previous electromagnetic protection device, the impact resistance capacity is smaller, and the surge The ability to withstand lightning strikes is relatively fragile, especially the transient impact of lightning strike overvoltage will cause serious damage to the microcomputer system. Therefore, the lightning protection problem of integrated automation and intelligent equipment such as microcomputer systems and computer networks is required to be included in the normal protection. .

Contents of the invention

In view of this, an embodiment of the present application provides a lightning protection power distribution cabinet, so as to avoid damage to the equipment to be protected by lightning.

In order to achieve the above objectives, the technical solutions provided in the embodiments of the present application are as follows:

A lightning protection power distribution cabinet, comprising a cabinet body and a lightning protection power supply circuit arranged in the cabinet body,

The lightning protection power supply circuit includes: a lightning protection circuit, an indicating device and an output unit, wherein,

The input end of the lightning protection circuit is connected to the power supply system, and the output end of the lightning protection circuit is connected to the output unit, which is used to eliminate the lightning surge voltage entering from the power supply system;

The lightning protection circuit includes a first-stage discharge unit, a second-stage current-blocking unit, and a third-stage clamping unit that are sequentially connected;

The indicating device is connected with the lightning protection circuit, and is used to display the current and voltage of each phase in the lightning protection circuit;

The output terminal of the output unit is connected with the equipment to be protected, and is used for supplying power to the equipment to be protected.

Preferably, in the lightning protection distribution cabinet provided in the embodiment of the present application, the ground wire of the lightning protection circuit is connected to the ground wire of the equipment to be protected.

Preferably, in the lightning protection distribution cabinet provided in the embodiment of the present application, the response time of the first-stage discharge element is 25 ns.

Preferably, the lightning protection distribution cabinet provided in the embodiment of the present application further includes: a direct power supply circuit and a switching circuit;

One end of the direct power supply circuit is connected to the power system, and the other end is connected to the equipment to be protected;

The switching circuit is respectively connected with the lightning protection power supply circuit and the through power supply circuit, and is used for conducting the lightning protection power supply circuit and disconnecting the through power supply circuit during lightning protection; 1. When the lightning protection circuit is faulty, overhauled or maintained, the direct power supply circuit is turned on, and the lightning protection power supply circuit is disconnected.

It can be seen from the above technical solutions that the lightning protection power distribution cabinet provided by the embodiment of the present application uses the lightning protection power supply path provided in the cabinet to pass the lightning surge voltage entering from the power supply system through the first-stage discharge unit, the second-stage The current-blocking unit and the third-level clamping unit perform three-level elimination, thereby preventing lightning surge voltage from being damaged by the power system to the equipment to be protected.

In addition, the lightning protection power distribution cabinet is also equipped with a through power supply circuit and a switching circuit. When there is less thunderstorm season (such as winter), the lightning protection circuit is faulty, repaired or maintained, the switching circuit can conduct the through power supply circuit, and the The lightning protection power supply circuit is disconnected, so that the power supply of the equipment to be protected can not be interrupted during maintenance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of the connection of the lightning protection power distribution cabinet provided in Embodiment 1 of the present application;

FIG. 2 is a schematic structural diagram of the lightning protection power distribution cabinet provided in Embodiment 1 of the present application;

FIG. 3 is a schematic structural diagram of a lightning protection power distribution cabinet provided in Embodiment 2 of the present application.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described The embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

At present, the lightning surge voltage mainly has the following intrusion methods:

1. Intrusion into the power system. The lightning strike directly hits the power line or the vicinity of the power line, and overvoltage is induced on the power line and transmitted to the power system;

2. Intrusion into the signaling system. The lightning induced voltage is introduced from the signal line;

3. Induction of space electromagnetic field. Lightning strikes the air receptor or building, and when the lightning current flows into the ground along the down-conductor, an alternating electromagnetic field is generated in the surrounding space, and overvoltage is induced on the power line or signal line;

4. Counterattack of ground potential. When the lightning current flows into the ground, due to the existence of grounding resistance, a large voltage drop will be generated, which will raise the ground potential and reverse the breakdown of the equipment; or the thundercloud will induce the opposite charge on the ground. If the thundercloud disappears, the ground will The charge in the ground will flow to infinity, which will raise the ground potential and produce a counterattack.

It can be seen that the protection against lightning surge overvoltage usually includes: the protection of the power supply system, the protection against electromagnetic shielding of the signal system, and the joint grounding body of the grounding system.

But due to power system intrusion is the most common. Therefore, in lightning protection, a lightning protection distribution cabinet must be equipped.

Embodiment one:

FIG. 1 is a schematic diagram of connection of a lightning protection power distribution cabinet provided in Embodiment 1 of the present application. Fig. 2 is a schematic diagram of the internal structure of the lightning protection distribution cabinet provided by the embodiment of the present application.

In FIG. 1 , 100 is a power supply system, 200 is a lightning protection power distribution cabinet, and 300 is equipment to be protected. As shown in FIG. 2 , the lightning protection power distribution cabinet 200 includes: a cabinet body and a lightning protection power supply circuit 1 .

The cabinet is usually set between the equipment to be protected and the power system, so that when a lightning strike occurs, the instantaneous lightning current of the power system should be discharged to the ground first, and at the same time, the induced overvoltage will be limited to a level that the equipment can withstand to avoid overvoltage voltage shock.

As shown in Figure 2, the lightning protection power supply circuit 1 includes: a lightning protection circuit 11, an indicating circuit 12 and an output circuit 13, wherein,

The input end of the lightning protection circuit 11 is connected to the power supply system 100 , and the output end of the lightning protection circuit 11 is connected to the output circuit 13 , which is used to eliminate the lightning surge voltage entering from the power supply system.

And as shown in FIG. 2, the lightning protection circuit includes: a first-stage discharge circuit 111, a second-stage blocking circuit 112 and a third-stage clamping circuit 113, wherein the first-stage discharge circuit 111, the second-stage The first-stage blocking circuit 112 and the third-stage clamping circuit 113 are electrically connected in sequence to realize three-stage protection against lightning voltage surges.

When protecting against lightning, the voltage threshold is preset in the first-stage discharge circuit 111. When the external voltage exceeds the voltage threshold, the discharge element in the first-stage discharge circuit 111 will instantaneously connect to the ground within 25ns. Discharge the lightning strike current; at the same time, the second-stage blocking circuit 112 is used to prevent the lightning strike current from continuing to pass through; finally, the third-stage clamping unit is used to limit the passage of excessive lightning surge voltage and clamp the output voltage within a safe value .

The output terminal of the output circuit 13 is connected to the device to be protected 300 for supplying power to the device to be protected 300 . In addition, the lightning protection power supply circuit can also provide normal power supply while performing lightning strike protection.

In addition, in order to facilitate the operator to understand the working status of the lightning protection circuit, the lightning protection circuit can also be provided with: indicating circuit 12,

The indicating circuit 12 is connected with the lightning protection circuit 11 and is used for displaying the current and voltage of each phase in the lightning protection circuit.

In order to increase the lightning protection performance of the lightning protection power distribution cabinet, the ground wire of the lightning protection circuit can also be connected with the system ground wire of the equipment to be protected, that is, the ground wire of the lightning protection circuit and the system ground wire of the equipment to be protected are implemented Equipotential bonding, so that the power supply system of all equipment to be protected is at the same basic potential.

The lightning protection power distribution cabinet provided in the embodiment of the present application uses the lightning protection power supply path provided in the cabinet to pass the lightning surge voltage entering from the power supply system through the first-stage discharge unit, the second-stage current blocking unit and the third-stage The three-level clamping unit performs three-level elimination, which can prevent the lightning surge voltage from being damaged by the power system to the equipment to be protected.

Embodiment two:

Since in the above-mentioned embodiment, only one path is provided in the lightning protection power distribution cabinet, when the lightning protection circuit breaks down, or when the lightning protection circuit needs to be repaired or maintained, the power to the equipment to be protected will be cut off, which will greatly affect the use of the equipment to be protected.

In order to avoid the uninterrupted power supply of the equipment to be protected due to the failure of the lightning protection circuit, or the need to overhaul and maintain the lightning protection circuit.

As shown in FIG. 3 , the lightning protection power distribution cabinet 200 provided in the embodiment of the present application further includes: a direct power supply circuit 3 and a switching circuit 4, wherein:

One end of the direct power supply circuit 3 is connected to the power system 100, and the other end is connected to the device to be protected 300;

The switching circuit 4 is connected to the lightning protection power supply circuit 1 and the through power supply circuit 3 respectively, and is used for turning on the lightning protection power supply circuit 1 and disconnecting the through power supply circuit 3 during lightning protection. ; When there is less thunderstorm season (such as winter), the lightning protection circuit is faulty, overhauled or maintained, the direct power supply circuit 3 is turned on, and the lightning protection power supply circuit 1 is disconnected.

Through the above solutions, the lightning protection power distribution cabinet can realize the uninterrupted power supply of the equipment to be protected during maintenance.

Since the lightning protection power distribution cabinet is also equipped with a through power supply circuit and a switching circuit, when there is less thunderstorm season (such as winter), the lightning protection circuit is faulty, overhauled or maintained, the switching circuit can conduct the through The lightning protection power supply circuit is disconnected, so that the power supply of the equipment to be protected can not be interrupted during maintenance.

The above descriptions are only preferred embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. a lightning protection power distribution cabinet, is characterized in that to equipment to be protected for the lightning surge voltage transmission that prevents from being entered by power-supply system, comprise cabinet and be arranged on the interior lightning protection power supply circuits of described cabinet,

Described lightning protection power supply circuits comprise: lightning protection circuit, indicating equipment and output unit, wherein,

The input of described lightning protection circuit is connected with power-supply system, and the output of described lightning protection circuit is connected with output unit, is used for eliminating the lightning surge voltage to being entered by power-supply system;

Comprise the first order vent unit, second level choke unit and the third level clamper unit that are connected successively in the described lightning protection circuit;

Described indicating equipment is connected with lightning protection circuit, is used for each phase current of every road, voltage in the described lightning protection circuit are shown;

The output of described output unit is connected with equipment to be protected, is used for powering to equipment to be protected.

2. circuit according to claim 1 is characterized in that, the ground wire of described lightning protection circuit links to each other with the ground wire of equipment to be protected.

3. method according to claim 2 is characterized in that, release response time of element of the described first order is 25ns.

4. method according to claim 3 is characterized in that, further comprises: straight-through power supply circuits and commutation circuit;

One end of described straight-through power supply circuits is connected with described power-supply system, and the other end is connected with equipment to be protected;

Described commutation circuit is connected with described lightning protection power supply circuits, straight-through power supply circuits respectively, is used for when lightning protection, and with the conducting of described lightning protection power supply circuits, and with described straight-through power supply circuits disconnection; When few thunderstorm season, lightning protection circuit fault, maintenance or maintenance, with described straight-through power supply circuits conducting, and with described lightning protection power supply circuits disconnection.

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