Power protection device for IO cabinet of PLC system

Abstract

The utility model discloses a power supply protection device for an IO cabinet of a PLC system. The power supply protection device comprises a main wire inlet switch, a circuit breaker module, a leakage protector and an IO cabinet power supply loop which are connected in sequence. By additionally arranging the leakage protector in the IO cabinet, the safety and reliability of the system can be remarkably improved. When the power supply loop in the IO cabinet has an electric leakage fault, the electric leakage protector can detect the leakage current in real time and rapidly cut off the power supply, thereby preventing the leakage current from causing potential harm to equipment and personnel. Besides, the rated current of the current circuit breaker is set to be consistent with the rated current of the leakage protector, so that override trip caused by improper capacity originally is avoided, and the continuity and safety of equipment operation are improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic power technology, and in particular to a protection device for the power supply of the IO cabinet of a PLC system. Background Technology

[0002] With the development of industrial automation, PLCs (Programmable Logic Controllers) are increasingly widely used in production lines and automated control systems. PLC systems are typically used to control and monitor various industrial equipment, such as sensors, actuators, and motors. The stability and security of PLC systems are crucial to ensuring the smooth operation of the entire automation system.

[0003] In a PLC system, the I / O cabinet serves as the interface connecting external devices and the PLC control system, undertaking crucial power distribution and electrical protection functions. The stability of the I / O cabinet's power supply directly affects the PLC system's operating status. Current power protection devices mostly focus on protecting individual circuits or devices, lacking comprehensive protection for the entire PLC system's I / O cabinet power circuit. Especially under faults such as current overload, short circuit, and leakage, traditional protection devices may fail to respond effectively and quickly, leading to damage to some equipment in the system and potentially causing serious electrical fires or other safety accidents.

[0004] While existing power protection technologies can protect individual electrical devices and lines, they lack sufficient flexibility and efficiency when dealing with complex multi-circuit power systems. Especially in PLC system I / O cabinets with multiple parallel circuits, electrical faults often spread from one circuit to others, leading to global failures. These technologies cannot effectively prevent damage to electrical components within the system and cannot achieve rapid isolation of fault sources. Utility Model Content

[0005] The purpose of this invention is to provide a power protection device for the IO cabinet of a PLC system, which improves the safety and stability of the power protection of the PLC system.

[0006] This utility model discloses a power protection device for a PLC system IO cabinet. The device includes a main incoming switch, a circuit breaker module, a leakage current protector, and an IO cabinet power circuit connected in sequence.

[0007] Furthermore, the circuit breaker module includes multiple current circuit breakers;

[0008] One end of each of the multiple current circuit breakers is connected together and then connected to the output terminal of the main incoming line switch;

[0009] At least one of the current circuit breakers is connected at one end to the input terminal of the residual current device.

[0010] Furthermore, the leakage current protector includes a leakage current detection module and a protection control module;

[0011] The leakage current detection module is connected to the main incoming switch through the circuit breaker module and is used to detect whether there is leakage current in the main incoming switch;

[0012] When the protection control module detects leakage current, it sends a control signal to control one or more current circuit breakers in the circuit breaker module to disconnect.

[0013] Furthermore, this also includes inter-transfer switch boxes;

[0014] The transfer switch box is connected to the circuit breaker module via the main incoming switch.

[0015] Furthermore, the IO cabinet power circuit includes multiple parallel branch circuit protection switches;

[0016] One end of each of the multiple branch circuit protection switches is connected to the output terminal of the leakage current protector.

[0017] The other end of the branch circuit protection switch is connected to the load device.

[0018] Furthermore, the rated current of the current circuit breaker is equal to the rated current of the residual current device.

[0019] Compared with the prior art, the present invention has at least the following technical effects:

[0020] This invention significantly improves the safety and reliability of the system by adding a residual current device (RCD) to the I / O cabinet. When a leakage current fault occurs in the power supply circuit of the I / O cabinet, the RCD can detect the leakage current in real time and quickly cut off the power supply, thereby preventing potential hazards to equipment and personnel and reducing the occurrence of safety accidents such as equipment damage or fires caused by leakage. Furthermore, the rapid response of the RCD in the event of a fault ensures that other parts of the system are not affected, improving the stability of the entire power supply system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the power protection device for a PLC system IO cabinet in one embodiment of the present invention. Detailed Implementation

[0022] The following description, with reference to schematic diagrams, illustrates a power protection device for a PLC system I / O cabinet according to the present invention, which shows a preferred embodiment of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the present invention.

[0023] The present invention will be described more specifically by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0024] This utility model discloses a power protection device for a PLC system IO cabinet, such as... Figure 1 As shown, the device includes: a main incoming line switch QF, a circuit breaker module 3, a residual current device QF2, and an I / O cabinet power circuit 2 connected in sequence.

[0025] In this embodiment, the addition of a residual current device (RCD) QF2 within the I / O cabinet significantly improves the system's safety and reliability. When a leakage current fault occurs in the power supply circuit within the I / O cabinet, the RCD QF2 can detect the leakage current in real time and quickly cut off the power supply, thereby preventing potential hazards to equipment and personnel. By promptly disconnecting the power, the RCD QF2 effectively prevents the spread of leakage faults, reducing the occurrence of safety accidents such as equipment damage or fires caused by leakage. Furthermore, the rapid response of the RCD QF2 during a fault ensures that other parts of the system are unaffected, improving the overall stability of the power supply system.

[0026] It is understood that the main incoming switch QF is typically installed on the power supply side of the PLC system. When the PLC system needs to be powered on, the main incoming switch QF will connect the external power supply to ensure that power enters the system. In the event of an electrical fault, the user or the system can use the main incoming switch QF to disconnect the power supply for maintenance or to prevent the accident from spreading.

[0027] In this embodiment, one end of the main incoming switch QF is connected to the power supply of the PLC system, and the other end is connected to the residual current device (RCD) QF2 through the circuit breaker module 3. The RCD QF2 then distributes the power to the downstream circuits. The current input monitoring function of the main incoming switch QF allows for real-time monitoring of current flow, enabling appropriate protective measures to be taken based on the current conditions.

[0028] In one specific embodiment, the main incoming switch QF can adopt a conventional double-position circuit breaker structure, which has two working states: closed and open.

[0029] In another specific embodiment, the specifications of the main incoming switch QF are selected according to the specifications of the load equipment, such as 50A, 63A, 80A, etc. Preferably, it is 50A. A 50A main incoming switch QF can meet the current requirements of high-power load equipment and multiple branch circuits, providing sufficient current carrying capacity and avoiding electrical system overload or failure due to excessive current.

[0030] In this embodiment, the power protection device further includes a transfer switch box 1.

[0031] Specifically, the transfer switch box is connected to the circuit breaker module 3 via the main incoming switch QF. The transfer switch box is typically used for switching between dual or multiple power supplies. When the PLC system needs to switch between different power supplies, this transfer switch box is used to ensure that electrical equipment can quickly switch to another available power supply when one power supply fails, improving the reliability of the system's power supply.

[0032] In one specific implementation, the transfer switch box includes two switches connected in parallel, and one end of the switches connected in parallel is connected to the circuit breaker module 3.

[0033] Furthermore, in this embodiment, the circuit breaker module 3 includes multiple current circuit breakers QF1. One end of each of the multiple current circuit breakers QF1 is connected to the output terminal of the main incoming switch QF; the other end of at least one of the current circuit breakers QF1 is connected to the input terminal of the residual current device QF2.

[0034] In one specific embodiment, the number of current circuit breakers QF1 is 4. Those skilled in the art can flexibly increase or decrease the number of current circuit breakers QF1 according to factors such as system scale, load distribution and backup requirements. For example, in actual scenarios, 3, 5 or 6 current circuit breakers QF1 can be selected to meet different power circuit configuration and protection requirements.

[0035] In another specific embodiment, the number of current circuit breakers QF1 connected to the input terminal of the leakage current protector QF2 can be 1, 2, or 3. Those skilled in the art can select the appropriate number of current circuit breakers QF1 to connect according to the actual situation to meet the specific requirements of the system for current protection and control.

[0036] In this embodiment, the rated current of the current circuit breaker QF1 is consistent with the rated current of the residual current device QF2.

[0037] By setting the rated current of the current circuit breaker QF1 to be consistent with the rated current of the residual current device QF2, the over-tripping caused by the previous inappropriate capacity is avoided. When a fault occurs, the power supply of the lower level can be disconnected first, thereby limiting the fault range to a smaller area. This not only improves the selective protection performance of the system, but also enhances the continuity and safety of equipment operation.

[0038] In one specific embodiment, the rated current of the current circuit breaker QF1 is 10A, therefore the rated current of the residual current device QF2 is also 10A. It is understood that those skilled in the art can flexibly adjust and select different current circuit breakers QF1 based on factors such as load power, line environment, and system load capacity requirements; for example, selecting a 16A, 20A, or 25A current circuit breaker QF1.

[0039] In this embodiment, the output terminal of the main incoming line switch QF is connected to a plurality of current circuit breakers QF1, and one end of each of the plurality of current circuit breakers QF1 is connected to the output terminal of the main incoming line switch QF.

[0040] In one specific embodiment, the circuit breakers in the residual current device QF2 are arranged in parallel, and are arranged on the same rail using terminals or busbars for easy installation and maintenance.

[0041] Furthermore, in this embodiment, the leakage current protector QF2 includes a leakage current detection module and a protection control module.

[0042] Specifically, the leakage current detection module is connected to the main incoming switch QF through the circuit breaker module 3, and is used to detect whether there is leakage current in the main incoming switch QF. When the protection control module detects leakage current, the protection control module sends a control signal to control one or more current circuit breakers QF1 in the circuit breaker module 3 to open.

[0043] For example, if a PLC system power supply line leaks to ground due to insulation aging, and the leakage current exceeds 30mA, the leakage current detection module in this embodiment will detect the abnormality and automatically disconnect the corresponding current circuit breaker QF1 through the protection control module command to ensure the normal operation of other parts of the system, while preventing the leakage accident from escalating and reducing the risk of equipment damage.

[0044] In this embodiment, the leakage current detection module is the zero-sequence current transformer in the leakage current protector QF2, and the protection control module is the electronic detection circuit in the leakage current protector QF2.

[0045] In one specific embodiment, the rated current of the residual current device (RCD) QF2 is 10A. Those skilled in the art can select the appropriate RCD based on factors such as the actual system load size, power distribution capacity, and equipment operating characteristics. For example, in applications with larger loads or higher safety requirements, higher or lower specifications of the RCD QF2 can be selected, such as 20A, 25A, and 32A RCDs. However, it is necessary to ensure that the rated current of the RCD QF2 is consistent with the rated current of the circuit breaker QF1.

[0046] In another specific embodiment, the leakage current detection module is installed above the main power supply circuit and adopts the form of a through-core current transformer to detect the current status in real time.

[0047] Furthermore, in this embodiment, the IO cabinet power circuit 2 is equipped with multiple branch circuit protection switches, each of which is connected to an independent load device. The IO cabinet power circuit 2 is mainly responsible for supplying power to the various power-consuming modules of the PLC system and for branching and managing the power supply.

[0048] In one specific embodiment, the number of branch circuit protection switches is 5. Those skilled in the art can flexibly increase or decrease the number of branch circuit protection switches according to the system scale, load quantity and safety protection requirements. For example, 4, 6 or 8 branch circuit protection switches can be configured in different application scenarios to achieve more refined independent protection for their respective loads.

[0049] In one specific embodiment, the branch circuit protection switches are connected in parallel on the same output terminal block, which can provide independent protection for the circuits they control.

[0050] In one specific embodiment, the rated current of the branch circuit protection switch is 6A. Those skilled in the art can flexibly select the appropriate type based on actual requirements such as load power, line environment, and required protection level. For example, protection switches of 4A, 6A, and 10A can also be selected. Furthermore, the rated current of each branch circuit protection switch can be the same or different, and needs to be selected based on the actual power of the load connected to each branch circuit protection switch, line environment, and required protection level.

[0051] In this embodiment, the load device may include PLC controllers, sensors, instruments, solenoid valves, frequency converters, and other actuators or control units commonly used in industrial automation systems. Those skilled in the art can select according to the actual situation.

[0052] The complete workflow of this system is as follows:

[0053] Under normal operating conditions, the external power supply (such as mains power or backup power) is first connected to the transfer switch box, which selects a suitable power output based on the actual operating status or backup strategy. Subsequently, this power supply enters the PLC system via the main incoming switch QF and is distributed through the leakage current protector QF2 to supply power circuit 2 of the IO cabinet. At this time, the leakage current detection module continuously monitors for abnormal current, while the protection switches of each branch circuit provide normal power to each load.

[0054] When current flows through the main incoming switch QF, if the leakage current detection module detects a leakage, it will immediately send the leakage information to the protection control module. Upon receiving the leakage signal, the protection control module will control the circuit breaker in the leakage current protector QF2 to quickly trip, cutting off the power supply to the faulty circuit and preventing the leakage from continuing.

[0055] When a short circuit or overload occurs in a branch circuit, the corresponding branch circuit protection switch will immediately trip and disconnect the faulty circuit. At the same time, the residual current device QF2 can also provide further disconnection protection when necessary.

[0056] In summary, this embodiment achieves multi-level protection from the main incoming line to each branch load by configuring a transfer switch box, circuit breaker module 3, and a residual current device (RCD) QF2 with leakage current detection and protection control in the PLC system's I / O cabinet. When leakage or line faults are detected, the RCD QF2 can quickly trip and isolate the faulty circuit, preventing the accident from spreading and protecting personnel and equipment safety. Furthermore, setting the rated current of the circuit breaker QF1 and the RCD QF2 to be the same reduces the risk of cascading tripping and improves the selectivity and reliability of system protection. Simultaneously, the transfer switch box supports main and backup power switching, ensuring continuous power supply during faults, thereby significantly improving the operational stability and safety of industrial automation.

[0057] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, the schematic diagram of this utility model includes these modifications and variations.

Claims

1. A power protection device for a PLC system IO cabinet, characterized by, The device comprises a main incoming line switch, a circuit breaker module, a leakage protector and an IO cabinet power supply loop connected in sequence; The leakage protector comprises a leakage current detection module and a protection control module; The leakage current detection module is connected with the main incoming line switch through the circuit breaker module, and is used for detecting whether there is leakage current in the main incoming line switch; The IO cabinet power supply loop comprises a plurality of parallel branch circuit protection switches; One end of the plurality of branch circuit protection switches is connected with the output end of the leakage protector, The other end of the branch circuit protection switch is connected with a load device.

2. The power protection device for a PLC system IO cabinet of claim 1, wherein, The circuit breaker module comprises a plurality of current circuit breakers; One end of the plurality of current circuit breakers is connected with the output end of the main incoming line switch; The other end of at least one current circuit breaker is connected with the input end of the leakage protector.

3. The power supply protection device for the IO cabinet of the PLC system according to claim 2, wherein When the protection control module detects leakage current, the protection control module sends a control signal to control one or more current circuit breakers in the circuit breaker module to be disconnected.

4. The power protection device for a PLC system IO cabinet of claim 2, wherein, The rated current of the current circuit breaker is equal to the rated current of the leakage protector.

5. The power protection device for a PLC system IO cabinet of claim 1, wherein, Further comprising a mutual backup switch box; The mutual backup switch box is connected with the circuit breaker module through the main incoming line switch.

6. A PLC system IO cabinet characterized by, The power supply protection device for the IO cabinet of the PLC system according to any one of claims 1-5 is adopted.

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