On-line monitoring device for current of transformer iron core grounding bar
By employing components such as open-core current transformers and signal conditioning circuits in the online monitoring device for transformer core grounding bar current, the problem of inaccurate monitoring under strong magnetic field conditions has been solved, enabling real-time and accurate monitoring of the core grounding bar current and ensuring the safe and stable operation of the power system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2026-03-13
AI Technical Summary
Existing technologies make it difficult to accurately monitor the transformer core grounding current in strong magnetic field environments, which makes it difficult to detect multiple grounding faults in the core in a timely manner, potentially causing the core to overheat or even burn out the transformer.
An open-type current transformer is used in conjunction with a signal conditioning circuit, a microprocessor module, a clock circuit, a display module, a power supply module, a communication module, and an address module. Through signal conditioning and data processing, real-time monitoring of the iron core grounding bus current is achieved, and electromagnetic interference is mitigated to improve measurement accuracy.
It enables accurate monitoring of transformer core grounding current in strong magnetic field environments, timely detection of insulation faults, and ensures power supply safety. The device is reasonably designed, has strong anti-electromagnetic interference capabilities, and is suitable for newly commissioned and in-service transformers.
Smart Images
Figure CN223992926U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power system monitoring technology, specifically an online monitoring device for monitoring the current of the transformer core grounding busbar. Background Technology
[0002] As a critical piece of equipment in power transmission and distribution systems, the operating status of transformers directly affects the safety and stability of the power system. Reliable grounding of the transformer core is a crucial measure to prevent multi-point grounding faults. Once the core insulation is damaged, leading to multiple grounding points, circulating currents will be generated inside the core, causing overheating and potentially even burning out the transformer. Therefore, real-time monitoring of the transformer core grounding drain current and timely detection and handling of insulation faults are of great significance for ensuring power supply safety. Utility Model Content
[0003] To address the problems existing in the prior art, this utility model proposes an online monitoring device for transformer core grounding busbar current, which aims to indirectly determine whether there is an insulation fault in the transformer core by monitoring the magnitude of the transformer core grounding busbar current.
[0004] The technical solution of this utility model is as follows:
[0005] An online monitoring device for transformer core grounding busbar current includes the following components:
[0006] Open-type through-core current transformer: This type employs a structure with a non-closed shielding layer made of pure iron, effectively solving the problem of environmental interference affecting through-core current transformers in strong magnetic fields. The permalloy iron core is combined with a 0.1mm diameter enameled wire coil, wound 100 times. The iron core has an inner diameter of 38mm and an outer diameter of 55mm. The opening is tightly sealed, and the entire unit is housed within a ring-shaped non-closed shielding layer made of pure iron, which is reliably grounded.
[0007] Signal conditioning circuit: This includes a rectifier circuit and resistive elements, converting AC current signals into DC voltage signals for easy acquisition by the microprocessor module. The rectifier circuit uses four Schottky diodes to form a full-bridge rectifier circuit, and the resistive elements are 100-ohm metal film resistors to reduce temperature drift.
[0008] Microprocessor module: It adopts the STM32F407ZGT6 chip, supports floating-point operations and DSP instructions, and has powerful data processing capabilities.
[0009] Clock circuit: Uses DS1302 chip to provide accurate time information.
[0010] Display module: The TJC4827K043_011 model 4.3-inch programmable touch serial screen is used to realize human-computer interaction.
[0011] Power supply module: The AP12N24-ZERO high-performance isolated power supply module is selected to convert the 220V / 50Hz AC mains power to 12VDC, and then converts it to 5VDC and 3.3VDC respectively through LM2596-5.0 and LMS1117-3.3 power chips to meet the power supply requirements of various parts of the device.
[0012] Communication module: The RSM485PHT type RS485 automatic transceiver is used to realize long-distance data transmission to the cloud platform.
[0013] Address module: Employs a 10-bit DIP switch to assign a unique address to each device, facilitating identification and management within the system.
[0014] The connection methods for the above modules are as follows:
[0015] The output terminal of the open-type current transformer is connected to the input terminal of the signal conditioning circuit, and the output terminal of the signal conditioning circuit is connected to the A / D port of the microprocessor module.
[0016] The clock circuit output is connected to the microprocessor module input I / O port.
[0017] The input terminal of the display module is connected to the I / O port of the output terminal of the microprocessor module;
[0018] The power module output is connected to the corresponding power interface of the microprocessor module.
[0019] The communication module input is connected to the corresponding communication interface of the microprocessor module output.
[0020] The address module output is connected to the microprocessor module input I / O port.
[0021] The beneficial effects of this utility model are:
[0022] 1. It solves the problem of environmental interference affecting through-hole current transformers in strong magnetic field environments, thus improving measurement accuracy.
[0023] 2. No power outage is required for installation, making it suitable for newly commissioned and in-service transformers, and it has wide applicability.
[0024] 3. By monitoring the transformer core grounding current in real time, insulation faults can be detected and dealt with in a timely manner, ensuring power supply safety.
[0025] 4. The device is reasonably designed, has strong anti-electromagnetic interference capabilities, and excellent electromagnetic compatibility performance.
[0026] In summary, the online monitoring device for transformer core grounding bar current of this utility model has the advantages of accurate measurement, convenient installation, strong versatility, and good monitoring effect, which is of great significance for ensuring the safe and stable operation of the power system. Attached Figure Description
[0027] Figure 1 This is a system block diagram of this utility model;
[0028] Figure 2 This is a diagram of the external shape of an open-core current transformer;
[0029] Figure 3 This is a diagram showing the connection interface between the display module and the microprocessor module;
[0030] Figure 4 This is a pin diagram of the microprocessor module;
[0031] Figure 5 This is a circuit diagram for converting 220VAC to 12VDC.
[0032] Figure 6 This is a circuit diagram for converting 12VDC to 5VDC.
[0033] Figure 7 This is a circuit diagram for converting 5VDC to 3.3VDC.
[0034] Figure 8 It is an RS485 communication circuit. Detailed Implementation
[0035] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.
[0036] like Figure 1 As shown, an online monitoring device for transformer core grounding bar current includes an open-type current transformer, a signal conditioning circuit, a microprocessor module, a clock circuit, a display module, a power supply module, a communication module, and an address module.
[0037] The output terminal of the open-type current transformer is connected to the input terminal of the signal conditioning circuit, and the output terminal of the signal conditioning circuit is connected to the A / D port of the microprocessor module.
[0038] The clock circuit output is connected to the microprocessor module input I / O port.
[0039] The input terminal of the display module is connected to the I / O port of the output terminal of the microprocessor module;
[0040] The power module output is connected to the corresponding power interface of the microprocessor module.
[0041] The communication module input is connected to the corresponding communication interface of the microprocessor module output.
[0042] The address module output is connected to the microprocessor module input I / O port.
[0043] like Figure 2 As shown, the open-type through-core current transformer employs a structure with a non-closed shielding layer made of pure iron material, effectively solving the problem of environmental interference in strong magnetic field environments. The permalloy iron core is combined with a 0.1mm diameter enameled wire coil, wound 100 times. The iron core has an inner diameter of 38mm and an outer diameter of 55mm. The opening is tightly joined, and the entire unit is housed within a ring-shaped non-closed shielding layer made of pure iron material, which is reliably grounded. The output terminal of the open-type through-core current transformer is connected to the input terminal of the signal conditioning circuit, and the output terminal of the signal conditioning circuit is connected to the A / D port of the microprocessor module.
[0044] Signal conditioning circuit: This includes a rectifier circuit and resistive elements, converting AC current signals into DC voltage signals for easy acquisition by the microprocessor module. The rectifier circuit uses four Schottky diodes to form a full-bridge rectifier circuit, and the resistive elements are 100-ohm metal film resistors to reduce temperature drift.
[0045] Microprocessor module: such as Figure 4 As shown, the STM32F407ZGT6 chip is used, which supports floating-point operations and DSP instructions, and has powerful data processing capabilities.
[0046] Clock circuit: Uses DS1302 chip to provide accurate time information.
[0047] Display module: A 4.3-inch programmable touchscreen serial port display (TJC4827K043_011) is used to achieve human-computer interaction. For example... Figure 3 As shown, the input terminal of the display module is connected to the I / O port of the microprocessor module output terminal;
[0048] Power Module: The power module uses the AP12N24-ZERO high-performance isolated power module, which converts 220V / 50Hz AC mains power to 12VDC. This power module internally includes surge protection circuitry and differential / common-mode filtering circuitry. Simultaneously, the 220VAC to 12VDC circuit has an input-side fuse F1 and a power-type thermistor R29 connected in series at the input terminal to suppress surge current during power-on. When an abnormal overvoltage input occurs, the varistor R30 immediately reduces its resistance to suppress interference from the overvoltage to subsequent circuits. The common-mode inductor LCM1 attenuates external common-mode electromagnetic interference and suppresses electromagnetic interference emitted by the receiver itself. Through the above circuit design, the device's electromagnetic interference immunity and electromagnetic compatibility performance are significantly improved. Figure 5It is a 220VAC to 12VDC circuit.
[0049] Since external devices require 5V, and the STM32 operates at 3.3V, this paper uses the LM2596-5.0 and LMS1117-3.3 power supply chips to convert 12VDC to 5VDC and 5VDC to 3.3VDC. The circuits are as follows: Figure 6 and Figure 7 As shown.
[0050] Communication module: such as Figure 8 As shown, the RSM485PHT RS485 automatic transceiver is used to achieve long-distance data transmission to the cloud platform.
[0051] Address module: Employs a 10-bit DIP switch to assign a unique address to each device, facilitating identification and management within the system.
[0052] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A transformer core grounding bar current on-line monitoring device, characterized in that, The open core current transformer, a signal conditioning circuit, a microprocessor module, a clock circuit, a display module, a power module, a communication module and an address module are included. The output end of the open core current transformer is connected with the input end of the signal conditioning circuit, and the output end of the signal conditioning circuit is connected with the input end A / D port of the microprocessor module. The output end of the clock circuit is connected with the input end I / O port of the microprocessor module. The input end of the display module is connected with the output end I / O port of the microprocessor module. The output end of the power module is connected with the corresponding power interface of the microprocessor module. The input end of the communication module is connected with the corresponding communication interface of the output end of the microprocessor module. The output end of the address module is connected with the input end I / O port of the microprocessor module.
2. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The open core current transformer comprises a pure iron material non-closed shielding layer, a permalloy core and a enameled wire coil, wherein the enameled wire coil with a wire diameter of 0.1 mm is wound on the open core permalloy core for 100 turns, the inner diameter of the permalloy core is 38 mm, the outer diameter is 55 mm, the opening is tightly combined, and the enameled wire coil is wound on the permalloy core, and then the whole is placed inside the annular non-closed shielding layer made of pure iron material, and the non-closed shielding layer made of pure iron material is reliably grounded.
3. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The signal conditioning circuit comprises a rectifier circuit and a resistance element, and the output end of the rectifier circuit is connected with the resistance element in parallel to convert the alternating current signal into a direct current voltage signal.
4. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The clock circuit adopts a DS1302 chip.
5. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The display module is specifically a TJC4827K043_011 type 4.3 inch programmable touch serial screen.
6. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The microprocessor module adopts an STM32F407ZGT6 chip.
7. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The power module selects an AP12N24-ZERO type high-performance isolation power module to convert the 220V / 50Hz alternating current into 12VDC, and converts it into 5VDC and 3.3VDC through LM2596-5.0 and LMS1117-3.3 power chips respectively.
8. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The communication module adopts an RSM485PHT type RS485 automatic transceiver.
9. The transformer core ground bank current online monitoring device according to claim 1, characterized in that, The address module adopts a 10-bit dial code switch.