CN203132720U - A temperature rise online monitoring device of a high-voltage device cable connector - Google Patents

Abstract

On-line monitoring device for temperature rise of cable joints of high-voltage equipment, including A-phase temperature acquisition circuit, B-phase temperature acquisition circuit, C-phase temperature acquisition circuit, ambient temperature acquisition circuit, microprocessor, display circuit and power supply circuit, three-phase temperature acquisition circuit and The ambient temperature acquisition circuit is correspondingly connected with the four A/D interfaces of the microprocessor in turn. The I/O port of the microprocessor is connected with the input port of the display circuit, and the output port of the power supply circuit is connected with the power supply terminal of the microprocessor. The power supply circuit includes a rectifier circuit, a filter circuit, a voltage stabilizing circuit and an energy storage circuit. The device can correctly judge the change of the temperature rise of the copper conductor at the joint of the three-phase high-voltage cable head, and provide a scientific and effective solution device for completely eliminating major accidents caused by the temperature rise failure of the cable head.

Description

High-voltage equipment cable joint temperature rise online monitoring device

technical field

The utility model relates to the field of on-line temperature rise monitoring circuit devices, in particular to an on-line temperature rise monitoring device for cable joints of high-voltage equipment. device for safe operation of the system.

Background technique

In order to ensure the safe operation of the power system, the diagnosis of thermal faults in the power system is generally valued by people. When the high-voltage bus is overloaded or the contact of the high-voltage switch is not in good contact, the contact resistance will become larger and heat will be generated when the load current flows. , This heating phenomenon causes insulation aging or even breakdown, thereby causing a short circuit, forming a major accident, and causing major economic losses.

In the power supply system using power cable transmission, according to the authoritative data analysis of the power industry, 90% of the failures of the fully inflated and fully insulated switchgear are due to the problems at the connection of the incoming and outgoing cables, and most of them are caused by on-site personnel who do not strictly follow the instructions of the cables. The installed cables cannot be directly judged whether the connection is well connected. If the installation is unreliable, the contact resistance of the installation will increase. During operation, the temperature rise of the contact part exceeds the allowable range stipulated by the state, causing the cable terminal to generate Insulation aging destroys the insulation capacity and causes single-phase ground fault or phase-to-phase short circuit accidents. Therefore, it is very important for the safe and reliable operation of the power system to detect and monitor the temperature of the cable joints of high-voltage equipment, and to detect and eliminate hidden dangers of thermal faults in advance. significance.

Utility model content

The purpose of the utility model is to provide an online monitoring device for the temperature rise of the cable joints of high-voltage equipment, which can diagnose the fault of the high-voltage switch contact and ensure the safe operation of the power system for the problem that it is difficult to monitor the temperature inside the cable.

The technical solutions adopted are:

The on-line monitoring device for temperature rise of cable joints of high-voltage equipment includes three temperature acquisition circuits with the same structure, an ambient temperature acquisition circuit, a microprocessor, a display circuit and a power supply circuit.

Its technical points are:

The three temperature acquisition circuits with the same structure are A phase temperature acquisition circuit, B phase temperature acquisition circuit and C phase temperature acquisition circuit. The output ends of the A-phase temperature acquisition circuit, the B-phase temperature acquisition circuit, the C-phase temperature acquisition circuit and the ambient temperature acquisition circuit are sequentially connected with the first A/D interface, the second A/D interface, and the third A/D interface of the microprocessor. The interface is correspondingly connected with the fourth A/D interface.

The I/O port of the microprocessor is connected with the input port of the display circuit, and the display circuit adopts an LCD display circuit, the model is TM1668.

The output port of the power supply circuit is connected with the power supply terminal of the microprocessor to provide power for it.

Microprocessor adopts single-chip microcomputer.

The interface circuit is connected with the serial port of the microprocessor. The interface circuit may be an RS485 wired interface circuit.

The power supply circuit includes a rectification circuit, a filter circuit, a voltage stabilizing circuit and an energy storage circuit. The output end of the rectifier circuit is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the voltage stabilizing circuit, the output end of the voltage stabilizing circuit is connected to the input end of the energy storage circuit, the output end of the energy storage circuit is connected to the micro Processor power terminal connection.

The input end of the rectification circuit is connected to the power output end of the high voltage live indicator. The input end of the rectification circuit is the input end of the power supply circuit, and the input end of the rectification circuit is connected to the shielding layer of the cable head at the same time to obtain the power signal.

The microprocessor can choose PIC, MSP430, msc51 series or AVR series and so on.

The interface circuit can also be a radio frequency interface circuit. The three temperature acquisition circuits and the ambient temperature acquisition circuit can also use temperature sensors to collect temperature signals. The three temperature sensors are respectively buried inside the insulation layer of the cable head of each phase to collect temperature signals. Digital temperature sensors AD590 and LM92 can be used.

The temperature sensor is embedded in the insulator and has sufficient insulation and isolation from the high-voltage end to realize the on-line detection of the heating temperature of the cable head. The heating part of the cable head is wrapped in the insulator, and the internal temperature rise cannot be measured externally. According to thermal theory, the temperature sensor is embedded in the insulator, and there is sufficient insulation and isolation from the high-voltage end, and the temperature sensor is embedded in the insulator to indirectly measure the temperature difference between the copper conductor at the high-voltage end and the ambient temperature, which realizes the heating of the cable head On-line temperature detection, this measurement method is safe and reliable, and the measurement data is accurate. It is suitable for the installation of new equipment and can also be applied to the transformation of old equipment.

Using radio frequency communication technology to wirelessly transmit the signal collected by the temperature sensor, the real-time temperature data can be sent to the post-microprocessor. In practical application, only three temperature sensors need to be buried inside the insulation layer of the high-voltage bushing, and another temperature sensor is placed near the cable joint to measure the ambient temperature around the cable head. The comparison of the temperature difference can accurately judge the temperature of the electrical connection of the cable head. The three temperature acquisition circuits and the ambient temperature acquisition circuit also have a modular structure, and the known products of Jiangsu Huatang Electric Appliance Co., Ltd. can be used, so the description will not be repeated.

The temperature acquisition circuit, ambient temperature acquisition circuit and power supply circuit can also adopt similar circuits with the same function, and the thermistor used can also select a 35KΩ thermistor for use.

Its advantages are:

The utility model adopts the field strength method to obtain the power supply voltage signal. It can provide stable working power for microprocessors and micro-power LCD display circuits, and can also measure parameters such as operating current, short-circuit current, and grounding current. The device is safe and reliable, and the measurement data is accurate. It is suitable for the installation of new equipment and can also be used for the transformation of old equipment. It mainly detects the temperature at the connection point of the cable head of the 6kV-35kV high-voltage equipment in operation, and adopts the online temperature of indirect contact and induction to take power. Measuring device, which mainly reflects the temperature rise of the copper conductor at the connection of the cable head indirectly by measuring the internal temperature of the insulating layer and the change of the ambient temperature. This monitoring device can correctly judge the temperature rise of the copper conductor at the connection of the three-phase high-voltage cable head. , this device does not need an external power supply. When the cable head of high-voltage equipment passes through the high-voltage signal, there is a capacitive effect between the cable conductor and the shielding layer of the cable head to obtain power supply power, which provides a way to completely eliminate major accidents caused by cable head temperature rise failures A scientific and effective solution.

Description of drawings

Fig. 1 is the schematic diagram of the utility model.

Detailed ways

The online monitoring device for the temperature rise of cable joints of high-voltage equipment includes three temperature acquisition circuits with the same structure, an ambient temperature acquisition circuit 4 , a microprocessor 5 , a display circuit 6 and a power supply circuit 8 .

The three temperature acquisition circuits with the same structure are A phase temperature acquisition circuit 1, B phase temperature acquisition circuit 2 and C phase temperature acquisition circuit 3 respectively. The output ends of A-phase temperature acquisition circuit 1, B-phase temperature acquisition circuit 2, C-phase temperature acquisition circuit 3 and ambient temperature acquisition circuit 4 are successively connected with the first A/D interface 9 and the second A/D interface of microprocessor 5 10. The third A/D interface 11 and the fourth A/D interface 12 are correspondingly connected.

The I/O port of the microprocessor 5 is connected with the input port of the display circuit 6, and the display circuit 6 adopts a low-power LCD display circuit, the model of which is TM1668.

The output port of the power supply circuit 8 is connected with the power supply terminal of the microprocessor 5 to provide power for it.

The microprocessor 5 adopts a micro-power consumption single-chip microcomputer. Microprocessor 5 selects MSP430 for use.

The interface circuit 7 is connected with the serial port of the microprocessor 5 . The interface circuit 7 can be an RS485 wired interface circuit. The interface circuit 7 is a communication interface circuit, which performs two-way communication with the microprocessor 5 and plays the role of an expansion interface.

The power supply circuit 8 includes a rectification circuit, a filter circuit, a voltage stabilizing circuit and an energy storage circuit. The output end of the rectifier circuit is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the voltage stabilizing circuit, the output end of the voltage stabilizing circuit is connected to the input end of the energy storage circuit, the output end of the energy storage circuit is connected to the micro Processor power terminal connection. The output end of the energy storage circuit is the output port of the power supply circuit 8 .

The input end of the rectification circuit is connected to the power output end of the high-voltage live indicator, the input end of the rectification circuit is the input end of the power supply circuit, and the input end of the rectification circuit is connected to the shielding layer of the cable head at the same time to obtain the power signal.

Three temperature acquisition circuits with the same structure and ambient temperature acquisition circuit 4 use a thermistor temperature acquisition circuit, thermistor model NTC10K3490 (10KΩ). The energy storage circuit can use supercapacitor energy storage, the model is ELNA company, DB-5R5D104.

The power supply circuit, the three temperature acquisition circuits and the ambient temperature acquisition circuit are all of modular structure and are known products of Jiangsu Huatang Electric Appliance Co., Ltd., so the description will not be repeated.

Claims (4)

1. The on-line monitoring device for the temperature rise of cable joints of high-voltage equipment, including three temperature acquisition circuits with the same structure, the ambient temperature acquisition circuit (4), the microprocessor (5), the display circuit (6) and the power supply circuit (8); Features: Three temperature acquisition circuits with the same structure are A-phase temperature acquisition circuit (1), B-phase temperature acquisition circuit (2) and C-phase temperature acquisition circuit (3); A-phase temperature acquisition circuit (1), B-phase temperature acquisition circuit The output ends of the circuit (2), the C-phase temperature acquisition circuit (3) and the ambient temperature acquisition circuit (4) are successively connected with the first A/D interface (9) and the second A/D interface ( 10), the third A/D interface (11) and the fourth A/D interface (12) are correspondingly connected; The I/O port of the microprocessor (5) is connected with the input port of the display circuit (6), and the output port of the power supply circuit (8) is connected with the power supply terminal of the microprocessor (5); The power supply circuit (8) comprises a rectification circuit, a filter circuit, a voltage stabilizing circuit and an energy storage circuit; the output end of the rectification circuit is connected with the input end of the filter circuit, the output end of the filter circuit is connected with the input end of the voltage stabilizing circuit, and the voltage stabilizing circuit The output end of the energy storage circuit is connected with the input end of the energy storage circuit, and the output end of the energy storage circuit is connected with the power supply end of the microprocessor. 2. The on-line monitoring device for temperature rise of cable joints of high-voltage equipment according to claim 1, characterized in that: the serial port of the microprocessor (5) is connected to the interface circuit (7); the interface circuit (7) is an RS485 wired interface circuit. 3. The on-line monitoring device for temperature rise of cable joints of high-voltage equipment according to claim 1 or 2, characterized in that the display circuit (6) adopts an LCD display circuit, the model of which is TM1668. 4. The on-line monitoring device for temperature rise of cable joints of high-voltage equipment according to claim 1 or 2, characterized in that the microprocessor (5) is a single-chip microcomputer.

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