Arc protector, arc protection system and switchgear

Abstract

The utility model provides an arc protector, arc protection system and switchgear, wherein the arc protector includes photosensitive circuit (1), it is used for inductive arc and generates induction current, triode (2) is connected in photosensitive circuit (1), triode (2) is used for amplifying induction current, and the induction current after amplification is inputted relay protection device, to make relay protection device carry out fault judgement according to the state of switch quantity, and the state of switch quantity is based on induction current generation. Through the combination of photosensitive circuit and triode, whether arc discharge problem occurs can be determined, and the combined structure is simple, and the cost is lower.

Description

Technical Field

[0001] This utility model relates to the field of power systems, and in particular to an arc flash protector, an arc flash protection system, and a switch cabinet. Background Technology

[0002] Switchgear is a crucial component of power systems, therefore its reliability and safe operation must be ensured to minimize electrical accidents. For example, if arc discharge occurs in the switchgear, appropriate protection mechanisms must be triggered promptly to prevent serious damage. Arc discharge refers to a gas discharge phenomenon that produces an arc and high temperature. For instance, arc discharge may occur during the contact or separation process between the moving and stationary contacts of a switchgear.

[0003] In existing technologies, dedicated arc sensors are typically used to detect arc light and determine whether arc discharge has occurred. However, these dedicated arc sensors are expensive. Utility Model Content

[0004] In view of this, the present invention proposes an arc flash protector, comprising:

[0005] A photosensitive circuit, used to sense arc light and generate an induced current;

[0006] A transistor is connected to the photosensitive circuit. The transistor is used to amplify the induced current and input the amplified induced current into the relay protection device so that the relay protection device can make fault judgment based on the state of the switching quantity, which is generated based on the induced current.

[0007] By combining a photosensitive circuit and a transistor, it is possible to determine whether an arc discharge problem has occurred. This combination has a simple structure and low cost.

[0008] Optionally, according to the arc flash protector described above, the base of the transistor is connected to the output terminal of the photosensitive circuit, and the emitter of the transistor is used to connect to the input terminal of the relay protection device, wherein the input terminal of the relay protection device is the BI port.

[0009] Optionally, the arc flash protector described above may further include at least one threshold adjustment circuit, each threshold adjustment circuit comprising:

[0010] An adjustable resistor, one end of which is connected to the base of the transistor;

[0011] A switch, one end of which is connected to the other end of the regulating resistor, and the other end of which is connected to the emitter of the transistor.

[0012] By closing the switch, the magnitude of the induced current distributed to the base of the transistor can be adjusted.

[0013] Optionally, the number of threshold adjustment circuits is two, according to the arc protection device described above.

[0014] Optionally, according to the arc protection device described above, the photosensitive circuit includes:

[0015] The first resistor has one end connected to the collector of the transistor and the input terminal of the relay protection device, respectively.

[0016] A photodiode, wherein the other end of the first resistor is connected to the anode of the photodiode, and the cathode of the photodiode is connected to the base of the transistor.

[0017] This photosensitive circuit consists of only a first resistor and a photodiode, and its structure is simple and its cost is low.

[0018] Optionally, the arc flash protector described above may further include a rectifier, the positive terminal of which is connected between the photosensitive circuit and the input terminal of the relay protection device, and the negative terminal of which is connected to the emitter of the transistor. This rectifier allows users to operate the arc flash protector without needing to distinguish between the positive and negative terminals, simplifying its use.

[0019] Optionally, the arc flash protector described above may further include a housing, within which both the photosensitive circuit and the transistor are located. The housing has an outwardly protruding spherical part corresponding to the photodiode in the photosensitive circuit. This allows the photodiode to generate a corresponding induced current.

[0020] This utility model also provides an arc flash protection system, including a relay protection device and an arc flash protector according to any one of the above claims, wherein the relay protection device is installed in a switch cabinet.

[0021] According to the arc flash protection system described above, optionally, there are multiple arc flash protectors, all of which are connected to the same relay protection device.

[0022] This utility model also provides a switch cabinet, characterized in that it includes an arc flash protector as described in any of the preceding claims. Attached Figure Description

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of the present invention, in which:

[0024] Figure 1 This is a schematic diagram of the structure of an arc flash protector according to an embodiment of the present invention.

[0025] The accompanying figure is labeled as follows:

[0026] 1-Photosensitive Circuit

[0027] 11-First Resistor

[0028] 12-Photodiode

[0029] 2-Transistor

[0030] 3-Threshold adjustment circuit

[0031] 31-Adjusting Resistor

[0032] 32-Switch

[0033] 4-Rectifier Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the following embodiments are provided to further illustrate this utility model in detail. The nouns and pronouns referring to "person" in this patent application are not limited to specific genders.

[0035] This invention provides an arc flash protector, which uses sensing light intensity to determine whether an arc discharge problem has occurred. The connections mentioned below can be direct or indirect.

[0036] like Figure 1 The diagram shown is a circuit structure diagram of an arc flash protector according to this invention. This arc flash protector can be placed near any component that may cause arc discharge problems to sense whether an arc is generated.

[0037] The arc flash protector includes a photosensitive circuit 1 and a transistor 2.

[0038] The photosensitive circuit 1 is used to sense the arc and generate an induced current. If an arc discharge occurs, the photosensitive circuit 1 can sense the arc and generate a corresponding induced current. More specifically, the induced current required in this application will only be generated when the intensity of the arc reaches a preset threshold, which can be set according to actual conditions.

[0039] Transistor 2 is connected to photosensitive circuit 1. Transistor 2 amplifies the induced current and inputs the amplified induced current into the relay protection device, enabling the relay protection device to determine the fault based on the state of the switching quantity. The state of the switching quantity is generated based on the induced current. Generally, the induced current is relatively small. Transistor 2 can amplify this induced current and input the amplified induced current into the relay protection device. When the induced current flows through the relay protection device, it will generate a switching quantity state. For example, there is one state corresponding to the absence of induced current, and another state corresponding to the presence of induced current. Simply put, the switching quantity state represents two states: on (power-on) and off (power-off). One state can be set to indicate that an arc discharge problem has occurred, and the other state indicates that an arc discharge problem has not occurred. Of course, the occurrence of an arc discharge problem can also be determined by whether the switching quantity state occurs. The specific settings can be configured according to actual needs. More specifically, the amplifying electrode of transistor 2 is connected to the input terminal of the relay protection device. When the input terminal of the relay protection device does not receive an induced current, the switching quantity is in one state. When the input terminal of the relay protection device receives a sufficiently large induced current, the state of the switching quantity changes to another state. The relay protection device can determine the fault by determining the real-time state of the switching quantity, or it can determine the fault by whether the state of the switching quantity changes. In this way, when the induced current flows through the relay protection device, the corresponding protection mechanism is triggered by judging the state of the switching quantity to avoid damage to the switch cabinet.

[0040] As an example, the base of transistor 2 is connected to the output of photosensitive circuit 1, and the emitter of transistor 2 is used to connect to the input of the relay protection device. The induced current, after exiting photosensitive circuit 1, is input to the base of transistor 2. Through the amplification effect of transistor 2, it flows out from the emitter of transistor 2 and then into the input of the relay protection device. As an example, this input can be a BI (Binary Input) port. Relay protection devices typically have multiple BI ports, so an unused BI port can be used to connect to the emitter of transistor 2, eliminating the need for a dedicated fiber optic interface or other specific interface to connect a dedicated arc sensor, thus reducing costs. The BI port is used to receive switching signals from external devices and convert these signals into binary signals that can be recognized by the control chip or circuit to obtain relevant information about the equipment or system within the switch cabinet. The BI port also typically has electrical isolation functionality, ensuring electrical isolation between the control side and the equipment side, thereby providing safe and reliable electrical signal conversion.

[0041] The transistor 2 here can be an NPN transistor or an NPN Darlington transistor. The two have different amplification capabilities for induced current, and the appropriate one can be selected according to actual needs.

[0042] In this way, by combining photosensitive circuit 1 and transistor 2, it is possible to determine whether an arc discharge problem has occurred. This combination has a simple structure and low cost.

[0043] As an example, the arc flash protector also includes at least one threshold adjustment circuit, each threshold adjustment circuit including an adjustment resistor 31 and a switch 32. The adjustment resistor 31 here can be, for example... Figure 1 The fixed resistor shown can also be a variable resistor, depending on the specific requirements. One end of switch 32 is connected to the other end of adjusting resistor 31, and the other end is connected to the emitter of transistor 2. By closing switch 32, the magnitude of the induced current distributed to the base of transistor 2 can be adjusted. Figure 1 The diagram illustrates a scenario with two threshold adjustment circuits. By opening or closing two switches 32, the magnitude of the induced current at the input base can be controlled by adjusting the current flowing into the threshold adjustment circuit. For example, when both switches 32 are open, a portion of the induced current at the input base is a proportion of the transistor-amplified induced current. When one switch 32 is open and the other is closed, the portion of the induced current at the input base is another proportion of the transistor-amplified induced current. And when both switches 32 are closed, the portion of the induced current at the input base is yet another proportion of the transistor-amplified induced current. Users can choose which mode to use based on their needs to ultimately set the threshold for the arc flash protection mechanism. As an example... Figure 1 As shown, assuming an arc discharge occurs at the contacts of the switchgear, the arc protection device detects the arc and generates a corresponding induced current, I1. The sum of the currents flowing into each threshold adjustment circuit is I2, and the current flowing into the base of transistor 2 is I3, where I1 = I2 + I3. Thus, by opening one switch 32, opening both switches 32, or closing both switches 32, I3 will differ while I1 remains constant, thereby setting different thresholds to trigger the arc protection mechanism.

[0044] As an example, the photosensitive circuit 1 includes a first resistor 11 and a photodiode 12. One end of the first resistor 11 is connected to the input terminal of the relay protection device, and the collector of the transistor 2 is connected to the input terminal of the relay protection device. The other end of the first resistor 11 is connected to the anode of the photodiode 12, and the cathode of the photodiode 12 is connected to the base of the transistor 2. The first resistor 11 provides a current path for the photodiode 12, which can sense the arc light and generate an induced current. The photodiode 12 can be any type of photodiode 12 available in the prior art, and can be selected according to actual needs. This photosensitive circuit 1 includes only one first resistor 11 and one photodiode 12, and its structure is simple and low in cost. It is conceivable that when the intensity of the arc light reaches a preset threshold, the photodiode 12 is turned on, thus forming a loop, and an induced current is generated in this loop. When this induced current flows through the input terminal of the relay protection device, it can change the state of the switching quantity.

[0045] As an example, the arc flash protector also includes a rectifier 4, the positive terminal of which is connected between the photosensitive circuit 1 and the input terminal of the relay protection device, and its negative terminal is connected to the emitter of the transistor 2. Figure 1 As can be seen, the positive terminal of rectifier 4 is connected to the photosensitive circuit 1, and the negative terminal is connected to the emitter of transistor 2. This rectifier 4 allows users to distinguish between the positive and negative terminals of the arc flash protector, making it convenient for customers. The rectifier 4 can be configured according to actual needs; the above description illustrates the case without rectifier 4.

[0046] As an example, the arc flash protector also includes a housing (not shown in the figure), within which the photosensitive circuit 1 and transistor 2 are located. Of course, the threshold adjustment circuit and rectifier 4 can also be located within the housing. For example, a circuit board is disposed within the housing, on which the photosensitive circuit 1 and transistor 2 are located, as are the threshold adjustment circuit and rectifier 4. The housing also has an outwardly protruding spherical body, specifically a hemisphere. This spherical body corresponds to the photodiode 12 in the photosensitive circuit 1. The function of this spherical body is to concentrate most of the light generated by the arc flash, after diffuse reflection, onto the photodiode 12. This allows the photodiode 12 to generate a corresponding induced current. The housing can be made of plastic with a certain light transmittance. The sphere is integrally formed with the housing.

[0047] This utility model also provides an arc flash protection system, which includes the arc flash protector and relay protection device described in any of the preceding claims. As an example, multiple arc flash protectors can be used. For instance, one arc flash protector can be placed at the contact of each circuit breaker in the switch cabinet. The three arc flash protectors corresponding to the three contacts can all be connected to the same relay protection device, specifically either the BI port of the same relay protection device or different BI ports of the same relay protection device. If different arc flash protectors are connected to different BI ports, it can be determined from the corresponding BI port which contact has experienced an arc discharge problem. If different arc flash protectors are connected to the same BI port, it can be determined that an arc discharge problem has occurred at the contact, and the specific contact can be further analyzed and determined through other methods. Of course, multiple arc flash protectors can also be placed at the same contact, connected to the same relay protection device, again either the BI port of the same relay protection device or different BI ports of the same relay protection device. Placing multiple arc flash protectors at the same contact allows for comprehensive detection of whether an arc discharge problem has occurred at that contact, resulting in high reliability. Figure 1 As shown, the arc flash protector has two ports, X1 and X2. Either port X1 or X2 can be connected to the BI port. The other unused port can also be connected to other arc flash protectors, thereby realizing the parallel connection between multiple arc flash protectors. After being connected in parallel, multiple arc flash protectors can all be connected to the same BI port.

[0048] The relay protection devices here are housed in the switch cabinet. For example, the switch cabinet door has an opening through which the operation panel of the relay protection device can be exposed, making it convenient for operators to operate the panel.

[0049] This utility model also provides a switch cabinet including the arc flash protector of any of the foregoing claims. Of course, the switch cabinet also includes the arc flash protection system of any of the foregoing claims.

[0050] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An arc flash protector, characterized in that, include: A photosensitive circuit (1) is used to sense arc light and generate induced current; Transistor (2) is connected to the photosensitive circuit (1). Transistor (2) is used to amplify the induced current and input the amplified induced current into the relay protection device so that the relay protection device can make fault judgment based on the state of the switching quantity. The state of the switching quantity is generated based on the induced current.

2. The arc flash protector according to claim 1, characterized in that, The base of the transistor (2) is connected to the output terminal of the photosensitive circuit (1), and the emitter of the transistor (2) is used to connect to the input terminal of the relay protection device, which is the BI port.

3. The arc flash protector according to claim 1, characterized in that, It also includes at least one threshold adjustment circuit, each threshold adjustment circuit comprising: Adjusting resistor (31), one end of which is connected to the base of transistor (2); A switch (32) is connected at one end to the other end of the regulating resistor (31) and at the other end to the emitter of the transistor (2).

4. The arc flash protector according to claim 3, characterized in that, The number of threshold adjustment circuits is 2.

5. The arc flash protector according to claim 1, characterized in that, The photosensitive circuit (1) includes: The first resistor (11) is connected at one end to the input terminal of the relay protection device, and the collector of the transistor (2) is connected to the input terminal of the relay protection device. A photodiode (12) is provided, with the other end of the first resistor (11) connected to the anode of the photodiode (12) and the cathode of the photodiode (12) connected to the base of the transistor (2).

6. The arc flash protector according to claim 1, characterized in that, Also includes: The rectifier (4) has its positive terminal connected between the photosensitive circuit (1) and the input terminal of the relay protection device, and its negative terminal connected to the emitter of the transistor (2).

7. The arc flash protector according to any one of claims 1-6, characterized in that, Also includes: The housing contains both the photosensitive circuit (1) and the transistor (2). The housing has an outwardly protruding spherical body, which corresponds to the photosensitive diode (12) in the photosensitive circuit (1).

8. An arc flash protection system, characterized in that, It includes a relay protection device and an arc flash protector according to any one of claims 1-7, wherein the relay protection device is installed in the switch cabinet.

9. The arc flash protection system according to claim 8, characterized in that, There are multiple arc flash protectors, all of which are connected to the same relay protection device.

10. A switch cabinet, characterized in that, The arc protection device includes any one of claims 1-7.

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