Power transformer oil temperature monitoring device

Abstract

The invention provides an oil temperature monitoring device for a power transformer. The oil temperature monitoring device comprises a temperature sensing unit, a digital sensing unit and a pointer type thermometer driven by a synchronous motor, a probe in the temperature sensing unit is arranged in transformer oil and is connected with the digital sensing unit in the pointer type thermometer through a sensing line, and the temperature sensing unit is composed of two temperature measuring elements; a monitoring module of the digital sensing unit periodically acquires four temperature signals of the two temperature measuring elements and compares the four temperature signals, and when the four temperature signals are consistent, the four temperature signals are normal or when a fault warning condition is met, a fault warning signal is generated, or when a channel switching condition is met, switching is carried out; and an electric signal carrying the direction, speed and duration for driving the synchronous motor to rotate is generated, so that the synchronous motor can control the pointer to rotate so as to display the oil temperature, and finally information is forwarded to peripheral equipment through the communication module. According to the invention, the defect of the sensor can be eliminated in an electrified manner, and the signal transmission requirement can be met.

Description

Technical Field

[0001] The invention relates to the technical field of power systems, and in particular to an oil temperature monitoring device for a power transformer. Background Art

[0002] At present, the oil temperature monitoring device used in oil-immersed power transformers mainly adopts pressure thermometers, whose sensors and meter bodies cannot be separated. Once the sensor fails, the power must be turned off and the entire product must be replaced, and it is impossible to eliminate the defect under power. In addition, the oil temperature monitoring device using pressure thermometers cannot meet the needs of signal transmission.

[0003] Therefore, it is necessary to design a new oil temperature monitoring device that can not only eliminate sensor defects under power but also meet signal transmission requirements. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide an oil temperature monitoring device for a power transformer, which can not only eliminate sensor defects under power, but also meet signal transmission requirements.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a power transformer oil temperature monitoring device, including a temperature sensing unit, a digital sensing unit, and a pointer thermometer whose dial is driven by a synchronous motor to rotate a pointer to display the temperature; wherein,

[0006] The temperature sensing unit includes a probe and a sensing line; the probe is disposed in the oil of a designated power transformer and is connected to a digital sensing unit located in the pointer thermometer through the sensing line, and is composed of two temperature measuring elements each having two signal outputs;

[0007] The digital sensing unit includes a monitoring module, a conversion module and a communication module; wherein,

[0008] One end of the monitoring module is connected to the sensing line, and the other end is connected to one end of the conversion module and one end of the communication module, and is used to periodically obtain four temperature signals formed by two temperature measuring elements and compare the sizes, and when the four temperature signals are consistent in a certain period, the four temperature signals are forwarded to the conversion module and the communication module; or, when the four temperature signals meet the predetermined fault alarm conditions in a certain period, a fault alarm signal is generated and forwarded to the communication module; or, when the four temperature signals meet the predetermined channel switching conditions in a certain period, the corresponding temperature signals are switched, and the switching status information is generated and forwarded to the communication module;

[0009] The other end of the conversion module is connected to the synchronous motor, and is used to generate an electrical signal carrying the direction, speed and duration of driving the synchronous motor to rotate according to the temperature signal when four temperature signals are received at the same time, and send the generated electrical signal to the synchronous motor, so that the synchronous motor can control the pointer on the dial of the pointer thermometer to rotate to the corresponding position based on the electrical signal, so as to correctly display the oil temperature of the specified power transformer;

[0010] The other end of the communication module is connected to an external device and is used to forward four-channel temperature signals, fault alarm signals and switching status information to the external device.

[0011] The temperature measuring element adopts double Pt100 chips and is armored with a metal protection tube.

[0012] The sensing wire is made of high temperature resistant polytetrafluoroethylene wire and is covered with a stainless steel metal hose for armor protection.

[0013] Among them, the monitoring module and the conversion module are both composed of a 4-series general-purpose single-chip microcomputer chip of model GD32F415RGO6 and peripheral circuits.

[0014] Wherein, the communication module is an RS485 communication module or a wireless communication module; wherein, the wireless communication module is composed of one or more of a Bluetooth module, a WIFI module, a 5G module, and a ZigBee module.

[0015] The predetermined fault alarm condition is that the four temperature signals are inconsistent.

[0016] The predetermined channel switching condition is that one temperature signal among the four temperature signals is inconsistent with the other three temperature signals, or two temperature signals among the four temperature signals are consistent.

[0017] Implementing the embodiments of the present invention has the following beneficial effects:

[0018] 1. The probe of the temperature sensing unit senses the oil temperature of the specified power transformer to form four temperature signals and enter the digital sensing unit along the sensing line, and the monitoring module of the digital sensing unit performs comparison, and the conversion module forms an electrical signal to drive the synchronous motor to control the pointer on the pointer thermometer to rotate to display the oil temperature. The communication module further sends the relevant information to the external device, so that the oil temperature of the power transformer can be displayed in real time and the signal transmission requirement can be met;

[0019] 2. The present invention is based on the separate design of the pointer thermometer and the temperature sensing unit. By comparing with the monitoring module of the digital sensing unit, the defects of the probe or the sensing line of the temperature sensing unit can be discovered in time. By disassembling and replacing the temperature sensing unit separately, the purpose of eliminating the sensor defects under power can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0021] Figure 1 A schematic diagram of the structure of a power transformer oil temperature monitoring device provided in an embodiment of the present invention;

[0022] Figure 2 The present invention is a schematic diagram of the structure of a digital sensing unit in a power transformer oil temperature monitoring device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 and Figure 2 As shown in the figure, an oil temperature monitoring device for a power transformer is proposed in an embodiment of the present invention, comprising a temperature sensing unit 1, a digital sensing unit 2, and a pointer-type thermometer 3 whose dial is driven by a synchronous motor (not shown) to rotate a pointer to display the temperature; wherein,

[0025] The temperature sensing unit 1 includes a probe 11 and a sensing line 12; the probe 11 is set in the oil of the designated power transformer and is connected to the digital sensing unit 2 located in the pointer thermometer 3 through the sensing line 12, and is composed of two temperature measuring elements each having two signal outputs; in one example, the temperature measuring element adopts a double-branch Pt100 chip and is armored with a metal protective tube, that is, two double-branch Pt100 chips are pre-embedded in the probe 11, which can simultaneously meet the four-way temperature signal output; the sensing line 12 adopts a high-temperature resistant polytetrafluoroethylene line (PTFE), the line length is 6 meters by default, and can be adjusted according to the temperature measurement point and the installation position of the pointer thermometer 3, and is covered with a stainless steel metal hose for armor protection;

[0026] The digital sensing unit 2 includes a monitoring module 21, a conversion module 22 and a communication module 23; wherein,

[0027] The monitoring module 21 is composed of a 4-series general-purpose single-chip microcomputer chip of model GD32F415RGO6 and a peripheral circuit. One end of the monitoring module 21 is connected to the sensing line 12, and the other end is connected to one end of the conversion module 22 and one end of the communication module 23. The monitoring module 21 is used to periodically (such as every 2 minutes) obtain the four temperature signals formed by the two temperature measuring elements and compare the sizes. When the four temperature signals are consistent in a certain period, the four temperature signals are forwarded to the conversion module 22 and the communication module 23; or, when the four temperature signals meet the predetermined fault alarm conditions (such as the four temperature signals are inconsistent) in a certain period, a fault alarm signal is generated and forwarded to the communication module 23; or, when the four temperature signals meet the predetermined channel switching conditions (such as one temperature signal among the four temperature signals is inconsistent with the other three temperature signals; for example, only two temperature signals among the four temperature signals are consistent, while the other two are inconsistent), the corresponding temperature signals are switched, and the switching status information is generated and forwarded to the communication module 23;

[0028] The conversion module 22 is composed of a 4-series general-purpose single-chip microcomputer chip of model GD32F415RGO6 and peripheral circuits, and the other end thereof is connected to the synchronous motor. When receiving four temperature signals at the same time, it generates an electrical signal (e.g., a 0-5V electrical signal) carrying the direction, speed and duration of driving the synchronous motor to rotate according to the temperature signal, and sends the generated electrical signal to the synchronous motor, so that the synchronous motor can control the pointer on the dial of the pointer thermometer 3 to rotate to the corresponding position based on the electrical signal, so as to correctly display the oil temperature of the specified power transformer;

[0029] The communication module 23 is an RS485 communication module or a wireless communication module, the other end of which is connected to an external device (such as a remote monitoring device) for forwarding four-way temperature signals, fault alarm signals and switching status information to the external device. The wireless communication module is composed of one or more of a Bluetooth module, a WIFI module, a 5G module, and a ZigBee module.

[0030] The pointer thermometer 3 comprises a housing, a synchronous motor, a pointer, a dial, a micro switch, etc., which are commonly used instruments in the art and will not be described in detail here.

[0031] It is understandable that the digital sensing unit 2 should be equipped with a power module to power all modules; in this case, the power module adopts an AC / DC dual-purpose power supply design of AC95-260V / DC100-300V.

[0032] The working principle of a power transformer oil temperature monitoring device in the embodiment of the present invention is that the oil temperature in the power transformer is first obtained through the probe 11 of the temperature sensing unit 1 to form a four-channel Pt100 temperature signal, and the four-channel temperature signal is transmitted to the digital sensing unit 2 in the pointer thermometer 3 through the sensing line 12. Then, the monitoring module 21 of the digital sensing unit 2 compares the four-channel Pt100 temperature signals. If the fault alarm condition is triggered, a fault alarm is issued, and the fault alarm signal is converted into a 485 communication signal and a Bluetooth communication signal, so that the communication module 23 reports; if the abnormality triggers the channel switching condition, it switches to a normal temperature signal, and converts the switching state information into a 485 communication signal and a Bluetooth communication signal, so that the communication module 23 reports; if the temperature signal is normal, it is transmitted to the conversion module 22, and the conversion module 22 converts the temperature signal into a 0-5V electrical signal to drive the synchronous motor and further drive the pointer to rotate to display the real-time temperature change, and converts it into a 485 communication signal and a Bluetooth communication signal so that the communication module 23 reports.

[0033] Implementing the embodiments of the present invention has the following beneficial effects:

[0034] 1. The probe of the temperature sensing unit senses the oil temperature of the specified power transformer to form four temperature signals and enter the digital sensing unit along the sensing line, and the monitoring module of the digital sensing unit performs comparison, and the conversion module forms an electrical signal to drive the synchronous motor to control the pointer on the pointer thermometer to rotate to display the oil temperature. The communication module further sends the relevant information to the external device, so that the oil temperature of the power transformer can be displayed in real time and the signal transmission requirement can be met;

[0035] 2. The present invention is based on the separate design of the pointer thermometer and the temperature sensing unit. By comparing with the monitoring module of the digital sensing unit, the defects of the probe or the sensing line of the temperature sensing unit can be discovered in time. By disassembling and replacing the temperature sensing unit separately, the purpose of eliminating the sensor defects under power can be achieved.

[0036] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A power transformer oil temperature monitoring device, characterized in that: The invention comprises a temperature sensing unit, a digital sensing unit and a pointer thermometer whose dial is driven by a synchronous motor to rotate a pointer to display the temperature; wherein, The temperature sensing unit includes a probe and a sensing line; the probe is disposed in the oil of a designated power transformer and is connected to a digital sensing unit located in the pointer thermometer through the sensing line, and is composed of two temperature measuring elements each having two signal outputs; The digital sensing unit includes a monitoring module, a conversion module and a communication module; wherein, One end of the monitoring module is connected to the sensing line, and the other end is connected to one end of the conversion module and one end of the communication module, and is used to periodically obtain four temperature signals formed by two temperature measuring elements and compare the sizes, and when the four temperature signals are consistent in a certain period, the four temperature signals are forwarded to the conversion module and the communication module; or, when the four temperature signals meet the predetermined fault alarm conditions in a certain period, a fault alarm signal is generated and forwarded to the communication module; or, when the four temperature signals meet the predetermined channel switching conditions in a certain period, the corresponding temperature signals are switched, and the switching status information is generated and forwarded to the communication module; The other end of the conversion module is connected to the synchronous motor, and is used to generate an electrical signal carrying the direction, speed and duration of driving the synchronous motor to rotate according to the temperature signal when four temperature signals are received at the same time, and send the generated electrical signal to the synchronous motor, so that the synchronous motor can control the pointer on the dial of the pointer thermometer to rotate to the corresponding position based on the electrical signal, so as to correctly display the oil temperature of the specified power transformer; The other end of the communication module is connected to an external device and is used to forward four-channel temperature signals, fault alarm signals and switching status information to the external device.

2. The oil temperature monitoring device for a power transformer according to claim 1, characterized in that: The temperature measuring element adopts double Pt100 chips and is armored and protected by a metal protection tube.

3. The oil temperature monitoring device for a power transformer according to claim 2, characterized in that: The sensing wire is made of high temperature resistant polytetrafluoroethylene wire and is covered with a stainless steel metal hose for armor protection.

4. The oil temperature monitoring device for a power transformer according to claim 3, characterized in that: The monitoring module and the conversion module are both composed of a 4-series general-purpose single-chip microcomputer chip of model GD32F415RGO6 and peripheral circuits.

5. The oil temperature monitoring device for a power transformer according to claim 4, characterized in that: The communication module is an RS485 communication module or a wireless communication module; wherein the wireless communication module is composed of one or more of a Bluetooth module, a WIFI module, a 5G module, and a ZigBee module.

6. The power transformer oil temperature monitoring device according to claim 5, characterized in that: The predetermined fault alarm condition is that the four temperature signals are all inconsistent.

7. The power transformer oil temperature monitoring device according to claim 6, characterized in that: The predetermined channel switching condition is that one temperature signal among the four temperature signals is inconsistent with the other three temperature signals, or two temperature signals among the four temperature signals are consistent.

Images