Electric leakage protection circuit and device for AC screen

Abstract

The utility model belongs to the technical field of leakage protectors, and particularly relates to an alternating current screen leakage protection circuit and device, and the circuit comprises a power management circuit which comprises a molded case switch and is used for the on-off of the current of an electrical load; and the breaking control circuit is connected with the power supply management circuit. According to the utility model, through cooperation of the power management circuit, the breaking control circuit, the electric leakage monitoring circuit and the connection control circuit, a setting value can be adjusted according to characteristics of an actual electrical load, an electric leakage current in an electrical load loop can be monitored in real time, and once it is monitored that the electric leakage current exceeds a preset setting value, the electric leakage current is monitored to be abnormal. The power supply can be quickly and automatically cut off to prevent electric shock, fire and other dangerous situations caused by electric leakage, the problem that traditional equipment is insensitive to small current leakage is effectively solved, the use flexibility is improved, and meanwhile, the safety and efficiency of electrical load equipment are remarkably improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of leakage protectors, and in particular relates to an AC screen leakage protection circuit and device. Background Art

[0002] AC panels are common key equipment in power systems. They are used to connect power supplies, transformers, converters and other loads, monitor and protect the power supply system, and have control functions such as connecting, disconnecting and switching between power supplies and various loads to achieve specified operating modes. Traditional AC panels mainly include components such as voltmeters, ammeters, switches, fuses, and signal lights. They are used in branch switch control distribution cabinets to achieve centralized control of electrical equipment. When encountering an emergency situation of leakage, it is often necessary to control it through the leakage protector of the AC panel.

[0003] Traditional leakage protection is implemented using molded case switches, which are usually compact and difficult to maintain, and are mostly manually operated, which can be delayed during use. When a leakage fault occurs, it is usually impossible to cut off the leakage current in time. The cumbersome use process leads to a relatively slow response time, which in turn damages the power load equipment, causing safety problems and property losses, and increasing potential safety risks. At the same time, the threshold for triggering leakage protection is often a fixed value, which cannot be adapted to different power load equipment and is not flexible.

[0004] Therefore, it is necessary to design a new AC screen leakage protection device to solve the above problems. Utility Model Content

[0005] The utility model aims to provide an AC screen leakage protection circuit and device, aiming to solve the technical problems in the prior art that the AC screen leakage protection is not timely enough and has poor use flexibility.

[0006] To achieve the above-mentioned purpose, an embodiment of the utility model provides an AC screen leakage protection circuit, including: a power management circuit, including a molded case switch, used to turn on and off the current of the power load; a disconnection control circuit, the disconnection control circuit is connected to the power management circuit, and is used to disconnect the power management circuit; a leakage monitoring circuit, the leakage monitoring circuit is connected between the power management circuit and the disconnection control circuit, and is used to monitor the leakage current of the power load circuit in real time; a connection control circuit, the connection control circuit is connected to the disconnection control circuit, and is used to control the power on and off of the disconnection control circuit.

[0007] Preferably, the disconnection control circuit includes a shunt release and a leakage protection relay, the shunt release is connected to the molded case switch and is used to drive the molded case switch to disconnect, the first pin of the leakage protection relay is connected to the load side port of the molded case switch, and the ninety-fifth pin of the leakage protection relay is connected to the first pin of the shunt release.

[0008] Preferably, the leakage monitoring circuit comprises a leakage current transformer, one end of the leakage current transformer is connected to the load side port of the molded case switch, and the other end of the leakage current transformer is connected to the 40th pin and the 41st pin of the leakage protection relay.

[0009] Preferably, the connection control circuit includes a first air switch, the first pin and the second pin of the first air switch are connected to the ninety-sixth pin of the leakage protection relay, and the third pin and the fourth pin of the first air switch are connected to the second pin of the shunt release.

[0010] Preferably, the connection control circuit also includes a second air switch, the first pin and the second pin of the second air switch are connected to the first pin of the leakage protection relay, the first air switch and the second air switch are connected in parallel and connected to the load side port of the molded case switch.

[0011] Preferably, the connection control circuit further comprises a transition terminal, which is connected between the shunt release and the leakage protection relay and is used to fix the wiring.

[0012] Preferably, the power side port of the molded case switch is connected to a current input, and the load side port of the molded case switch is connected to a power load device.

[0013] The embodiment of the utility model also provides an AC screen leakage protection device, which is provided with the AC screen leakage protection circuit.

[0014] The above one or more technical solutions in the AC screen leakage protection circuit and device provided by the embodiment of the utility model have at least one of the following technical effects:

[0015] The utility model can adjust the set value according to the characteristics of the actual power load through the cooperation of the power management circuit, the disconnection control circuit, the leakage monitoring circuit and the connection control circuit, and can monitor the leakage current in the power load circuit in real time. Once the leakage current is detected to exceed the preset set value, the power supply will be automatically cut off quickly to prevent dangerous situations such as electric shock and fire caused by leakage. The utility model effectively solves the problem of insensitivity of traditional equipment to small current leakage, improves the flexibility of use, and significantly improves the safety and efficiency of power load equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 A schematic diagram of the structure of the AC screen leakage protection circuit provided by the embodiment of the utility model;

[0018] Figure 2 A circuit schematic diagram of an AC screen leakage protection circuit provided in an embodiment of the utility model.

[0019] Among them, the reference numerals in the figure are:

[0020] 1-power management circuit, 2-disconnection control circuit, 3-leakage monitoring circuit, 4-connection control circuit. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0022] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0024] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0025] In one embodiment of the present invention, Figure 1-Figure 2 As shown, an AC screen leakage protection circuit is provided, including a power management circuit 1, a disconnection control circuit 2, a leakage monitoring circuit 3 and a connection control circuit 4.

[0026] In this embodiment, the power management circuit 1 includes a molded case switch SK for switching the current of the power load. The power side port of the molded case switch SK is connected to the current input, and the load side port of the molded case switch SK is connected to the power load device.

[0027] In this embodiment, the disconnection control circuit 2 is connected to the power management circuit 1, and is used to perform a disconnection operation on the power management circuit 1. The disconnection control circuit 2 includes a shunt release FL and a leakage protection relay ASJ, the shunt release FL is connected to the molded case switch SK, and is used to drive the molded case switch SK to disconnect, the first pin of the leakage protection relay ASJ is connected to the load side port of the molded case switch SK, and the ninety-fifth pin of the leakage protection relay ASJ is connected to the first pin of the shunt release FL.

[0028] Taking into account the adaptation to different power consumption environments, the leakage protection relay ASJ can set different setting values. The leakage protection relay ASJ receives the current signal transmitted by the leakage current transformer LBCT in real time and analyzes and displays it. When the leakage current is greater than the preset setting value, the leakage protection relay ASJ will drive the shunt release FL, so that the molded case switch SK cuts off the fault current and protects the power load equipment.

[0029] In this embodiment, the leakage monitoring circuit 3 is connected between the power management circuit 1 and the disconnection control circuit 2, and is used to monitor the leakage current of the power load circuit in real time. The leakage monitoring circuit 3 includes a leakage current transformer LBCT, one end of which is connected to the load side port of the molded case switch SK, and the other end of which is connected to the 40th pin and the 41st pin of the leakage protection relay ASJ.

[0030] When the circuit is working, the leakage current transformer LBCT can monitor and measure the leakage current value of the circuit on the load side of the molded case switch SK in real time, and output the current signal to the leakage protection relay ASJ for real-time display and judgment. When the circuit is in normal working state, the sum of the three-phase current in the power load circuit and the current vector in the neutral line is close to zero, and only weak leakage current can be monitored; when a ground fault occurs in the power load circuit, the sum of the current vector of the three-phase current and the neutral line will increase, and a large leakage current will be generated. At this time, the leakage current value detected by the leakage current transformer LBCT reaches the preset setting value, and the corresponding current signal is sent to the leakage protection relay ASJ to drive the shunt release FL to disconnect.

[0031] In this embodiment, the connection control circuit 4 is connected to the disconnection control circuit 2, and is used to control the power on and off of the disconnection control circuit 2. The connection control circuit 4 includes a first air switch QF1, the first pin and the second pin of the first air switch QF1 are connected to the ninety-sixth pin of the leakage protection relay ASJ, and the third pin and the fourth pin of the first air switch QF1 are connected to the second pin of the shunt release FL. The connection control circuit 4 also includes a second air switch QF2, the first pin and the second pin of the second air switch QF2 are connected to the first pin of the leakage protection relay ASJ, and the first air switch QF1 and the second air switch QF2 are connected in parallel and connected to the load side port of the molded case switch SK.

[0032] In actual use, the first air switch QF1 is used to control the power on and off of the shunt release FL. When the system detects that the power needs to be cut off, the first air switch QF1 transmits the signal to the second pin of the shunt release FL through the triggering of the leakage protection relay ASJ, thereby cutting off the power of the molded case switch SK and realizing the disconnection operation; the second air switch QF2 is used to control the power on and off of the leakage protection relay ASJ. The cooperation of the two air switches ensures the reliable operation of key equipment in the system. It not only improves the overall reliability of the leakage protection device, but also ensures the accuracy of the power on and off, thereby further improving the safety and stability of the system.

[0033] Specifically, the connection control circuit 4 also includes a transition terminal DZ, which is connected between the shunt release FL and the leakage protection relay ASJ and is used to fix the wiring. The transition terminal DZ can also ensure the effective electrical connection between the shunt release FL and the leakage protection relay ASJ. When the transition terminal DZ is applied to the drawer-type AC panel, considering the flexible use of space, an empty terminal can be reserved, which makes it more convenient in future expansion or changes, and increases maintainability and upgradeability.

[0034] The embodiment of the utility model also provides an AC screen leakage protection device, which is provided with the AC screen leakage protection circuit.

[0035] It should be noted that the present application aims to protect the circuit structure. For the program control part, technical personnel in this field should select appropriate circuits and chips according to the chip models in the present application or as needed and perform appropriate programming to realize the corresponding program control function in the present utility model. Therefore, this part is a mature and established technology in the prior art and is not the focus of protection of this application. Therefore, this application does not elaborate on this control part.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An AC screen leakage protection circuit, characterized in that: include: A power management circuit, including a molded case switch, is used to switch the current of the power load on and off; A disconnection control circuit, the disconnection control circuit is connected to the power management circuit and is used to perform a disconnection operation on the power management circuit; A leakage monitoring circuit, which is connected between the power management circuit and the disconnection control circuit and is used to monitor the leakage current of the power load circuit in real time; A connection control circuit is connected to the disconnection control circuit and is used to control the power on and off of the disconnection control circuit.

2. The AC screen leakage protection circuit according to claim 1 is characterized in that: The disconnection control circuit includes a shunt release and a leakage protection relay. The shunt release is connected to the molded case switch and is used to drive the molded case switch to disconnect. The first pin of the leakage protection relay is connected to the load side port of the molded case switch, and the ninety-fifth pin of the leakage protection relay is connected to the first pin of the shunt release.

3. The AC screen leakage protection circuit according to claim 2 is characterized in that: The leakage monitoring circuit includes a leakage current transformer, one end of which is connected to the load side port of the molded case switch, and the other end of which is connected to the 40th pin and the 41st pin of the leakage protection relay.

4. The AC screen leakage protection circuit according to claim 3 is characterized in that: The connection control circuit includes a first air switch, wherein the first pin and the second pin of the first air switch are connected to the ninety-sixth pin of the leakage protection relay, and the third pin and the fourth pin of the first air switch are connected to the second pin of the shunt releaser.

5. The AC screen leakage protection circuit according to claim 4 is characterized in that: The connection control circuit also includes a second air switch, a first pin and a second pin of the second air switch are connected to the first pin of the leakage protection relay, and the first air switch and the second air switch are connected in parallel and connected to the load side port of the molded case switch.

6. The AC screen leakage protection circuit according to claim 3 is characterized in that: The connection control circuit also includes a transition terminal, which is connected between the shunt release and the leakage protection relay and is used to fix the wiring.

7. The AC screen leakage protection circuit according to claim 3 is characterized in that: The power supply side port of the molded case switch is connected to a current input, and the load side port of the molded case switch is connected to an electric load device.

8. An AC screen leakage protection device, characterized in that: An AC screen leakage protection circuit as described in any one of claims 1 to 7 is provided.

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