CN110057489B - Power transformer online monitoring device and method based on transient oil pressure characteristics - Google Patents
Power transformer online monitoring device and method based on transient oil pressure characteristics Download PDFInfo
- Publication number
- CN110057489B CN110057489B CN201910375876.7A CN201910375876A CN110057489B CN 110057489 B CN110057489 B CN 110057489B CN 201910375876 A CN201910375876 A CN 201910375876A CN 110057489 B CN110057489 B CN 110057489B
- Authority
- CN
- China
- Prior art keywords
- oil pressure
- transformer
- module
- transient
- threshold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L15/00—Devices or apparatus for measuring two or more fluid pressure values simultaneously
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Housings And Mounting Of Transformers (AREA)
Abstract
A power transformer on-line monitoring device and method based on transient oil pressure characteristics comprises a transient oil pressure characteristic measurement module, a signal conditioning and acquisition module and a digital processing and analysis module; transient oil pressure characteristic quantity measuring module and signal conditioning link to each other with collection module, and signal conditioning links to each other with collection module and digital processing analysis module, and data storage module, man-machine dialogue module and data communication interface module all link to each other with digital processing analysis module. The invention obtains transient oil pressure characteristic information of a plurality of measuring points in the transformer oil tank in real time, calculates an action oil pressure value representing the oil pressure amplitude of the transformer, and judges whether the tested transformer generates abnormal overvoltage or not by comparing the action oil pressure value with a preset overvoltage threshold value and a quasi-overvoltage threshold value. The device is independent of a power network, and has the advantages of simple structure, easy realization, reliability, accuracy and the like.
Description
Technical Field
The invention belongs to the field of power systems, and relates to a power transformer online monitoring device and method based on transient oil pressure characteristics, which are used for measuring, recording and analyzing the transient oil pressure characteristics of an oil-immersed power transformer and evaluating the running state of the transformer according to the transient oil pressure characteristics.
Background
As a key electric power main device, a transformer plays a very important role in an electric power system, and the stable operation of the transformer is an important prerequisite for ensuring the reliable transmission, flexible distribution and safe use of electric energy of the whole electric power system. With the continuous improvement of the capacity and the voltage grade of the power system, higher requirements are put forward on the reliability and the safety of the power transformer. However, in the peak period of power consumption in summer, an explosion or ignition accident of the transformer body due to an internal failure sometimes occurs. Especially for the high-voltage class and large-capacity junction transformer, because the junction transformer is expensive in manufacturing cost, complex in structure and provided with a large amount of loads, once explosion and fire occur, serious economic loss is caused. In addition, tens of tons of combustible insulating oil are contained in the large transformer, so that hot oil splashes and fire light impacts the sky when an explosion and a fire happen, the life and property safety of operating personnel in a station and surrounding residents are seriously threatened, and the social stability is seriously influenced.
The transformer oil as the petroleum extract has the advantages of good insulating property, lower viscosity, good heat transfer property, low manufacturing cost and the like. Since the end of the 19 th century, power transformers began to be filled with such paraffinic heavy oils for use as cooling and insulating media. Except for medium and small-capacity transformers with special purposes and individual gas-insulated transformers, oil-immersed transformers using transformer oil as filler are widely applied to power systems with different capacity and voltage class requirements.
At present, large-scale power transformers are all oil-immersed power transformers, and the oil tank of the large-scale power transformer contains several tons to tens of tons of transformer insulating oil. The monitoring of the instantaneous oil pressure characteristics of the insulating oil of the transformer has great significance for evaluating the running state of the transformer and judging whether the transformer fails or not. On one hand, when serious overheating or arc fault occurs inside the oil-immersed power transformer, the liquid insulating oil is instantly vaporized and decomposed to form high internal energy bubbles with a certain volume. Under the continuous injection of fault electric energy, the internal pressure of a fault bubble is also increased continuously, and meanwhile, due to the expansion inertia of the liquid insulating oil near a fault point, a gas-liquid phase interface between the fault bubble and the surrounding liquid insulating oil inevitably generates obvious pressure increase and propagates in the transformer oil tank in the form of pressure waves, so that the integral sudden increase of the internal oil pressure of the oil tank is caused. On the other hand, when an overheat fault occurs inside the transformer, the rise in the temperature of the insulating oil also causes a change in the pressure of the insulating oil. Therefore, the method has important reference value for the transformer operation and maintenance personnel to evaluate the safe operation state of the transformer aiming at the real-time measurement, recording, operation and analysis of the oil pressure in the transformer oil tank.
Disclosure of Invention
The invention aims to provide a power transformer on-line monitoring device and method based on transient oil pressure characteristics, which are used for measuring, recording and analyzing the transient oil pressure characteristics of an oil-immersed power transformer and evaluating the running state of the transformer according to the transient oil pressure characteristics.
In order to achieve the purpose, the invention adopts the following technical scheme:
a power transformer on-line monitoring device based on transient oil pressure characteristics comprises a transient oil pressure characteristic measurement module, a signal conditioning and acquisition module and a digital processing and analysis module; the device comprises a transient oil pressure characteristic quantity measuring module, a signal conditioning and collecting module, a digital processing and analyzing module, a data storage module, a man-machine conversation module and a data communication interface module, wherein the transient oil pressure characteristic quantity measuring module is connected with the signal conditioning and collecting module;
the transient oil pressure characteristic quantity measuring module is used for measuring oil pressure change characteristics of different positions in the transformer and outputting corresponding analog voltage/current signals;
the signal conditioning and acquisition module is used for receiving the analog voltage/current signal output by the transient oil pressure characteristic quantity measuring module, converting the analog voltage/current signal into a standard digital signal which can be identified by the digital processing and analysis module, and outputting the standard digital signal;
the digital processing and analyzing module is used for receiving the standard digital signal and then executing monitoring operation to complete the task of processing the standard digital signal, thereby realizing the functions of on-line monitoring of transient oil pressure in the oil tank and evaluation of the running state of the transformer.
The invention has the further improvement that the transient oil pressure characteristic quantity measuring module consists of a plurality of high-frequency dynamic oil pressure sensors and communication cables thereof; the high-frequency dynamic oil pressure sensor is arranged on the transformer body, and a probe at the end part of the sensor is directly contacted with the transformer insulating oil to measure the internal oil pressure change characteristics of different positions of the transformer and output corresponding analog voltage/current signals by utilizing the communication cable.
The invention has the further improvement that the measuring frequency of the high-frequency dynamic oil pressure sensor is 20kHz, the measuring error is less than 1 percent, the working temperature is-45-120 ℃, and the measuring range is-0.1-6 MPa.
The invention has the further improvement that the signal conditioning and collecting module consists of a wiring terminal, a signal conditioning circuit, a low-pass filter, a signal sampling circuit and an analog-digital A/D conversion circuit; the wiring terminal is connected with the signal conditioning circuit, the signal conditioning circuit is connected with the low-pass filter, the low-pass filter is connected with the signal sampling circuit, and the signal sampling circuit is connected with the analog-to-digital A/D conversion circuit; the wiring terminal is also connected with a communication cable.
The invention has the further improvement that the digital processing analysis module consists of a bus, a central processing unit, a GPS synchronous clock, a random access memory, a read-only memory and a control circuit; the central processing unit, the GPS synchronous clock, the random access memory and the control circuit are all connected with the bus; the analog-to-digital A/D conversion circuit is connected with the bus; the bus comprises a data bus, an address bus and a control bus, and realizes data exchange and operation control; the central processing unit is a single-chip microprocessor, a general microprocessor or a digital signal processor and realizes digital signal processing; the GPS synchronous clock is used for realizing the synchronous sampling requirement of each station device in the transformer substation and the system; the random access memory is used for temporarily storing temporary data, including data information input by the signal conditioning and acquisition module and intermediate results in the calculation processing process; the read-only memory is used for storing data; the control circuit realizes the connection and coordination work of the whole digital circuit by utilizing the field programmable gate array.
The invention has the further improvement that the invention also comprises a data storage module, a man-machine conversation module and a data communication interface module which are connected with the digital processing analysis module;
the data storage module is used for storing data;
the man-machine conversation module is used for establishing information contact between the online monitoring device and a user so as to facilitate manual operation, debugging and information feedback of an operator on the online monitoring device;
the data communication interface module is used for realizing information interaction, data transmission, remote operation and remote maintenance with other equipment and a central station.
The invention has the further improvement that the data storage module consists of a main flash memory and an auxiliary flash memory; the main flash memory and the auxiliary flash memory are used as a main memory and a standby memory of the online monitoring device;
the man-machine conversation module comprises a compact keyboard, a display screen, an indicator light, a button and a printer interface;
the data communication interface module follows an IEC 61850 communication protocol, and information interaction, data transmission, remote operation and remote maintenance between other equipment and a master station are realized by utilizing Ethernet.
A monitoring method of the power transformer on-line monitoring device based on the transient oil pressure characteristics comprises the following steps:
the transient oil pressure characteristic quantity measuring module is used for measuring oil pressure change characteristics of different positions in the transformer, namely reading oil pressure p of n measuring points in the transformer at the current time tms.n(t), n is 1,2,3 … …; and outputs the corresponding analog voltage/current signal; the signal conditioning and acquisition module is used for receiving the analog voltage/current signal output by the transient oil pressure characteristic quantity measuring module, converting the analog voltage/current signal into a standard digital signal which can be identified by the digital processing and analysis module, and outputting the standard digital signal;
secondly, the digital processing analysis module receives the standard digital signal and then judges the instantaneous oil pressure p of each measuring pointms.n(t) and a predetermined starting threshold pstIf the instantaneous oil pressure p at any measuring pointms.n(t) is greater than or equal to a preset starting threshold pstI.e. of the formula(1) If yes, entering the step III; if the oil pressure of all the measuring points is less than the preset starting threshold pstIf the formula (1) is not satisfied, the oil pressure inside the transformer is normal, and the process goes to the fifth step;
pms.n(t)-pst≥0 (1)
calculating the action oil pressure p at the moment of each measuring point t by using the following formulaop.n(t)：
In the formula (2), T is the length of a data window, and f is the signal sampling frequency of an acquisition module;
determining the operating oil pressure pop.n(t) and overpressure alarm threshold pth.1If the hydraulic pressure p is actuatedop.n(t) is greater than or equal to overvoltage alarm threshold pth.1If the formula (3) is true, sending out the over-voltage alarm in the transformer, and entering the fifth step; if the operating oil pressure pop.n(t) if the value is smaller than the overvoltage alarm threshold, namely the formula (3) does not hold, entering a step (iv);
pop.n(t)-pth.1≥0 (3)
judging the operating oil pressure pop.n(t) and quasi-overvoltage warning threshold pth.2If p is the size ofop.n(t) quasi-overvoltage early warning threshold pth.2If the formula (4) is established, sending out an early warning of quasi-overpressure in the oil tank, and entering a fifth step; if p isop.n(t) is less than quasi-overvoltage early warning threshold pth.2If the formula (4) is not satisfied, the oil pressure in the oil tank is normal;
pop.n(t)-pth.2≥0 (4)
storing the measured oil pressure data and communicating the oil pressure data to a master station;
sixthly, self-checking is carried out in the running state, if the device is found to be in fault, an alarm signal is sent out, the whole device is locked, and technicians are waited for removing the fault and manually resetting; if no fault is found, the procedure returns to step I, and the oil pressure p at the next moment is read againms.n(t+1)。
The invention is further improved in that in the step II, a starting threshold p is presetstSet to 35 kPa;
in step III, the length T of the data window is 5 multiplied by 10-3s, over-voltage alarm threshold pth.1Is 70 kPa.
The invention has the further improvement that in the step IV, the quasi-overvoltage early warning threshold pth.2Is 55 kPa.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the internal oil pressure change characteristics of different positions of the transformer are measured by the transient oil pressure characteristic quantity measuring module, so that the requirements of high-temperature, greasy dirt and strong electromagnetic environment in the power transformer can be met no matter the precision or the application range is high; the on-line monitoring device is independent of a power network, the measurement of the oil pressure characteristics and the signal transmission are less interfered, and harmonic waves are not injected into a power system; the digital processing and analyzing module can completely meet the requirements of processing multi-channel and high-frequency data quickly and in real time. The invention has the advantages of simple structure, easy realization, reliability, high efficiency and the like.
Furthermore, the high-frequency dynamic oil pressure sensor with the measurement frequency of 20kHz, the measurement error of less than 1 percent, the working temperature of-45-120 ℃ and the range of-0.1-6 MPa is adopted, and the high-frequency dynamic oil pressure sensor can meet the requirements of high-temperature, greasy dirt and strong electromagnetic environment in the power transformer no matter the precision or the use range.
During monitoring, the transient oil pressure characteristic measurement module, the signal conditioning and acquisition module and the digital processing and analysis module are physically connected and functionally matched to form the power transformer online monitoring device based on the transient oil pressure characteristics. Meanwhile, the monitoring device is controlled according to an online monitoring principle and functional requirements, and the operations of measuring, calculating, recording, communicating and the like of the transient oil pressure of the tested transformer are realized. The method comprises the steps of obtaining action oil pressure capable of completely representing average kinetic energy of oil pressure in a transformer through filtering and integral operation of transient oil pressure data of a plurality of measuring points in the transformer, and comparing the action oil pressure with a preset starting threshold, an overvoltage alarm threshold and a quasi-overvoltage early warning threshold to realize real-time monitoring and evaluation of the oil pressure level in the transformer. The method has important engineering practical significance for transformer operators to accurately and reliably acquire transient oil pressure data of the transformer oil tank in real time and evaluate the safe operation state of the transformer. The device can run reliably for a long time, is not influenced by strong electromagnetism and oil pollution environments, has the advantages of high response speed and high measurement frequency, does not inject harmonic waves into a power system in the running process, and does not influence the normal running of primary and secondary equipment in a transformer substation.
Drawings
FIG. 1 is a schematic diagram of the structure of the device of the present invention.
FIG. 2 is a logic flow diagram of the present invention.
Fig. 3 is a field test actual measurement result of the transformer on-line monitoring device based on the transient oil pressure characteristics.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
Referring to fig. 1, an on-line monitoring device for power transformer based on transient oil pressure characteristics includes: the device comprises a transient oil pressure characteristic quantity measuring module, a signal conditioning and collecting module, a digital processing and analyzing module, a data storage module, a man-machine conversation module and a data communication interface module. Transient oil pressure characteristic quantity measuring module and signal conditioning link to each other with collection module, and signal conditioning links to each other with collection module and digital processing analysis module, and data storage module, man-machine dialogue module and data communication interface module all link to each other with digital processing analysis module.
The transient oil pressure characteristic quantity measuring module consists of n high-frequency dynamic oil pressure sensors and communication cables thereof. The high-frequency dynamic oil pressure sensor is arranged on the transformer body, a probe at the end part of the sensor is required to be directly contacted with the transformer insulating oil to measure the internal oil pressure change characteristics of different positions of the transformer, and a communication cable is utilized to output analog voltage/current signals corresponding to the internal oil pressure change characteristics.
The signal conditioning and collecting module consists of a wiring terminal, a signal conditioning circuit, a low-pass filter, a signal sampling circuit and an analog-to-digital (A/D) conversion circuit. The wiring terminal is connected with the signal conditioning circuit, the signal conditioning circuit is connected with the low-pass filter, the low-pass filter is connected with the signal sampling circuit, and the signal sampling circuit is connected with the analog-to-digital A/D conversion circuit; the wiring terminal is also connected with a communication cable. The signal conditioning and acquisition module is used for receiving the analog voltage/current signal output by the transient oil pressure characteristic quantity measuring module, converting the analog voltage/current signal into a standard digital signal which can be identified by the digital processing and analysis module, and outputting the standard digital signal.
The digital processing analysis module consists of a bus, a Central Processing Unit (CPU), a GPS synchronous clock, a Random Access Memory (RAM), a read-only memory (ROM) and a control circuit. The central processing unit, the GPS synchronous clock, the random access memory, the read-only memory and the control circuit are all connected with the bus; the analog-to-digital A/D conversion circuit is connected with the bus; the bus comprises a data bus, an address bus and a control bus, and realizes data exchange, operation control and the like. The Central Processing Unit (CPU) is a command center of the digital processing and analyzing module, and can rapidly realize digital signal processing in real time through devices such as a single chip microprocessor, a general microprocessor, a Digital Signal Processor (DSP) and the like. And the GPS synchronous clock is adopted to realize strict synchronous sampling requirements of devices in each station of the transformer substation and the system. The Random Access Memory (RAM) is used for temporarily storing a large amount of temporary data needing to be quickly exchanged, including data information input by the signal conditioning and acquisition module, intermediate results in the calculation processing process and the like. Read Only Memory (ROM) is used to hold data. The control circuit utilizes a Field Programmable Gate Array (FPGA) to realize effective connection and coordination work of the whole digital circuit. The digital processing and analyzing module is used for receiving the standard digital signal and then executing monitoring operation, completing a digital signal processing task, commanding the normal operation of the connected modules, and realizing data exchange and operation control, thereby realizing the functions of on-line monitoring of transient oil pressure in the oil tank and evaluation of the running state of the transformer.
The data storage module is used for storing data; the data storage module consists of a main Flash Memory and an auxiliary Flash Memory (Flash Memory). The main flash memory and the secondary flash memory are used as a main memory and a standby memory of the online monitoring device.
The man-machine conversation module comprises a compact keyboard, a display screen, an indicator light, a button, a printer interface and the like. The method is used for establishing information contact between the online monitoring device and a user so as to facilitate the manual operation and debugging of an operator on the online monitoring device, obtain information feedback and the like.
The data communication interface module follows an IEC 61850 communication protocol, and information interaction, data transmission, remote operation, remote maintenance and the like between other equipment and a master station are realized by utilizing the Ethernet.
Referring to fig. 2, according to the monitoring method of the power transformer online monitoring device based on the transient oil pressure characteristics, the online monitoring device is controlled according to the online monitoring principle and the functional requirements, so as to implement operations such as measurement, operation, recording, communication, state evaluation and the like of the transient oil pressure of the tested transformer. The specific process is as follows:
firstly, after a power supply is switched on (power-on for short) or hardware is reset (reset for short), the online monitoring device firstly executes system initialization to ensure that the whole device is in a normal working state.
Secondly, performing comprehensive self-checking after power-on, detecting the correctness and integrity of the working state of the device, sending an alarm signal and locking the whole device if the device is found to be defective, and waiting for technical personnel to remove the fault and manually reset.
Thirdly, if the oil pressure characteristic measurement module passes through self-checking, the transient oil pressure characteristic measurement module is used for measuring oil pressure change characteristics of different positions in the transformer, namely, oil pressure p of n measuring points in the transformer at the current moment t is readms.n(t), n is 1,2,3 … …; and outputs the corresponding analog voltage/current signal; the signal conditioning and acquisition module is used for receiving the analog voltage/current signal output by the transient oil pressure characteristic quantity measuring module, converting the analog voltage/current signal into a standard digital signal which can be identified by the digital processing and analysis module, and outputting the standard digital signal;
fourthly, the digital processing analysis module receives the standard digital signal and then judges the instantaneous oil pressure p of each measuring pointms.n(t) and a predetermined starting threshold pstIs greater than or equal to, the starting threshold pstAnd may be set to 35 kPa. If any one of the measuring points is instantaneously pressedms.n(t) is equal to or greater than a starting threshold pstI.e. formula (1) toIf so, entering the fifth step; if all the measuring points are less than the starting threshold pstIf the formula (1) is not satisfied, it indicates that the internal oil pressure of the transformer is normal, and step (c) is performed.
pms.n(t)-pst≥0 (1)
Using the following formula to calculate the action oil pressure p at the time t of each measuring pointop.n(t)：
In the formula (2), T is the length of the data window, and may be 5 × 10-3And s. f is the signal sampling frequency of the acquisition module. Determining the operating oil pressure pop.n(t) and overpressure alarm threshold pth.1Size of (1), pth.1Normally, the working oil pressure p can be set to 70kPaop.n(t) is greater than or equal to overvoltage alarm threshold pth.1If the formula (3) is established, sending out an over-voltage alarm inside the transformer; if the operating oil pressure pop.nAnd (t) if the value is smaller than the overvoltage alarm threshold, namely the formula (3) is not established, entering the step (c).
pop.n(t)-pth.1≥0 (3)
Sixth, judging the oil pressure pop.n(t) and quasi-overvoltage warning threshold pth.2Size of (1), pth.2Usually, it is set to 55kPa, if pop.n(t) quasi-overvoltage early warning threshold pth.2If the formula (4) is established, sending out an early warning of quasi-overvoltage in the oil tank; if p isop.n(t) is less than quasi-overvoltage early warning threshold pth.2If the expression (4) is not satisfied, the oil pressure inside the oil tank is normal.
pop.n(t)-pth.2≥0 (4)
And storing the measured oil pressure data and communicating the oil pressure data to a master station.
And automatically checking in the running state, if the device is found to be in fault, sending an alarm signal and locking the whole device, and waiting for a technician to remove the fault and manually reset. If no fault is found, the step returns to step three, and the oil pressure p at the next moment is read againms.n(t+1)。
The power transformer online monitoring device based on the transient oil pressure characteristics is formed by physically connecting and functionally matching a transient oil pressure characteristic quantity measuring module, a signal conditioning and collecting module, a digital processing and analyzing module, a data storage module, a man-machine conversation module and a data communication interface module. Meanwhile, the online monitoring device is controlled according to the online monitoring principle and the functional requirements, and the operations of measuring, calculating, recording, communicating and the like of the transient oil pressure of the tested transformer are realized.
The device can realize real-time digital measurement, acquisition and operation of the oil pressure characteristic information in the oil tank on the premise of not damaging the existing structural integrity of the transformer. Furthermore, the silicon piezoresistive high-frequency dynamic pressure sensor with the measurement frequency of 20kHz, the measurement error of less than 1 percent, the working temperature of-45-120 ℃ and the range of-0.1-6 MPa is adopted, so that the high-temperature, oil stain and strong electromagnetic environment in the power transformer can be met no matter the precision or the use range is achieved; the online monitoring of the invention is independent of the power network, the measurement and transmission of the pressure characteristics are less interfered, and no harmonic wave is injected into the power system; the data acquisition and processing element can completely meet the requirements of processing multi-channel and high-frequency data rapidly and in real time. The invention has the advantages of simple structure, easy realization, reliability, high efficiency and the like.
Furthermore, the invention obtains the action oil pressure capable of completely representing the average kinetic energy of the oil pressure in the transformer by filtering and integrating transient oil pressure data of a plurality of measuring points in the transformer, and realizes real-time monitoring and evaluation of the oil pressure level in the transformer by comparing the action oil pressure with a preset starting threshold, an overvoltage alarm threshold and a quasi-overvoltage early warning threshold. The invention originally provides a device and a method for monitoring a power transformer on line based on transient oil pressure characteristics, and the application of the device and the method has important engineering practical significance for transformer operators to accurately and reliably obtain transient oil pressure data of a transformer oil tank in real time and evaluate the safe operation state of the transformer. The device can run reliably for a long time, is not influenced by strong electromagnetism and oil pollution environments, has the advantages of high response speed and high measurement frequency, does not inject harmonic waves into a power system in the running process, and does not influence the normal running of primary and secondary equipment in a transformer substation.
The SFSZ8-40000/110 three-phase three-winding transformer is used as a test platform for field test to illustrate the effect of the invention, and the main geometric structure and the nameplate parameters of the transformer are shown in Table 1. As shown in FIG. 3, when the transformer is normally operated (t < 0ms), the oil pressure in the transformer tank does not change significantly, and the device measures the operating oil pressure pop.1、pop.2、pop.3Are all far smaller than overvoltage alarm threshold pth.1And quasi-overvoltage early warning threshold pth.2The device can not send out alarm or early warning signals and display that the oil pressure in the transformer body is normal. When the transformer breaks out of an internal arc fault at the moment when t is 0ms, the oil pressure at each point inside the transformer is rapidly increased due to the injection of fault energy. When t is 10.68ms, the device measures the operating oil pressure p obtained by calculationop.1Threshold p for early warning of over-voltageth.2The device of the invention will send out a quasi-overvoltage early warning. When t is 12.95ms, the device measures the operating oil pressure p obtained by calculationop.1Is greater than overvoltage alarm threshold p firstth.1The device of the invention can send out the over-voltage warning of the transformer. The field test result shows that: the device can sense and obtain the internal pressure change characteristics of the oil-immersed power transformer in a very short time, obtain the action oil pressure capable of representing the internal oil pressure danger level of the transformer through calculation, and evaluate the current running state and the safety level of the transformer according to comparison with the preset criterion. And important reference data and judgment basis are provided for field operators and transformer manufacturing enterprises.
TABLE 1 SFSZ8-40000/110 Transformer principal geometry and nameplate parameters
While the invention has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (3)
1. A power transformer online monitoring method based on transient oil pressure characteristics is characterized by comprising the following steps:
the transient oil pressure characteristic quantity measuring module is used for measuring oil pressure change characteristics of different positions in the transformer, namely reading oil pressure p of n measuring points in the transformer at the current time tms.n(t), n is 1,2,3 … …; and outputs the corresponding analog voltage/current signal; the signal conditioning and acquisition module is used for receiving the analog voltage/current signal output by the transient oil pressure characteristic quantity measuring module, converting the analog voltage/current signal into a standard digital signal which can be identified by the digital processing and analysis module, and outputting the standard digital signal;
secondly, the digital processing analysis module receives the standard digital signal and then judges the instantaneous oil pressure p of each measuring pointms.n(t) and a predetermined starting threshold pstIf the instantaneous oil pressure p at any measuring pointms.n(t) is greater than or equal to a preset starting threshold pstIf the formula (1) is established, entering the step (c); if the oil pressure of all the measuring points is less than the preset starting threshold pstIf the formula (1) is not satisfied, the oil pressure inside the transformer is normal, and the process goes to the fifth step;
pms.n(t)-pst≥0 (1)
calculating the action oil pressure p at the moment of each measuring point t by using the following formulaop.n(t)：
In the formula (2), T is the length of a data window, and f is the signal sampling frequency of an acquisition module;
determining the operating oil pressure pop.n(t) and overpressure alarm threshold pth.1If the hydraulic pressure p is actuatedop.n(t) is greater than or equal to overvoltage alarm threshold pth.1If the formula (3) is true, sending out the over-voltage alarm in the transformer, and entering the fifth step; if the operating oil pressure pop.n(t) if the value is smaller than the overvoltage alarm threshold, namely the formula (3) does not hold, entering a step (iv);
pop.n(t)-pth.1≥0 (3)
judging the operating oil pressure pop.n(t) and quasi-overvoltage warning threshold pth.2If p is the size ofop.n(t) quasi-overvoltage early warning threshold pth.2If the formula (4) is established, sending out an early warning of quasi-overpressure in the oil tank, and entering a fifth step; if p isop.n(t) is less than quasi-overvoltage early warning threshold pth.2If the formula (4) is not satisfied, the oil pressure in the oil tank is normal;
pop.n(t)-pth.2≥0 (4)
storing the measured oil pressure data and communicating the oil pressure data to a master station;
sixthly, self-checking is carried out in the running state, if the device is found to be in fault, an alarm signal is sent out, the whole device is locked, and technicians are waited for removing the fault and manually resetting; if no fault is found, the procedure returns to step I, and the oil pressure p at the next moment is read againms.n(t+1)。
2. The on-line monitoring method for power transformer based on transient oil pressure characteristics as claimed in claim 1, wherein in step (II), a preset starting threshold p is setstSet to 35 kPa;
in step III, the length T of the data window is 5 multiplied by 10-3s, over-voltage alarm threshold pth.1Is 70 kPa.
3. The electric power of claim 1 based on transient oil pressure characteristicsThe transformer on-line monitoring method is characterized in that in the step IV, the quasi-overvoltage early warning threshold pth.2Is 55 kPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910375876.7A CN110057489B (en) | 2019-05-07 | 2019-05-07 | Power transformer online monitoring device and method based on transient oil pressure characteristics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910375876.7A CN110057489B (en) | 2019-05-07 | 2019-05-07 | Power transformer online monitoring device and method based on transient oil pressure characteristics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110057489A CN110057489A (en) | 2019-07-26 |
| CN110057489B true CN110057489B (en) | 2021-04-27 |
Family
ID=67322512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910375876.7A Active CN110057489B (en) | 2019-05-07 | 2019-05-07 | Power transformer online monitoring device and method based on transient oil pressure characteristics |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110057489B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110631762B (en) * | 2019-11-01 | 2021-06-15 | 国网江苏省电力有限公司电力科学研究院 | Method for determining internal pressure criterion for mutual inductor fault early warning |
| CN112013983B (en) * | 2020-08-28 | 2022-04-12 | 重庆大学 | Transformer multipoint temperature and oil pressure combined monitoring device and method based on differential inductive sensor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20080076489A (en) * | 2007-02-16 | 2008-08-20 | 주식회사 한솔테크 | Fault pressure relay for power transformer |
| CN202420748U (en) * | 2011-12-30 | 2012-09-05 | 天威云南变压器股份有限公司 | Monitoring system for oil pressure in transformer oil tank |
| CN204009562U (en) * | 2014-08-27 | 2014-12-10 | 山东电力设备有限公司 | Transformer body travel position on-line monitoring system |
| CN106207969A (en) * | 2016-08-08 | 2016-12-07 | 河南开启电力实业有限公司 | Transformer station's oil-filled transformer on-line monitoring early warning system |
| CN208206204U (en) * | 2018-06-19 | 2018-12-07 | 三峡大学 | Network distribution transformer on-Line Monitor Device based on GPS positioning |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001124648A (en) * | 1999-10-29 | 2001-05-11 | Mitsubishi Electric Corp | Pressure measuring device |
| CN2596199Y (en) * | 2002-12-30 | 2003-12-31 | 管延波 | Over-pressure protector for electromagnetic instrument pressure container |
| JP2005302794A (en) * | 2004-04-07 | 2005-10-27 | Hitachi Industrial Equipment Systems Co Ltd | Transformer monitoring system |
| CN201397375Y (en) * | 2009-05-12 | 2010-02-03 | 上海电力变压器修试厂有限公司 | Pressure detection device for pressure relay |
| CN103278312B (en) * | 2013-03-30 | 2015-07-01 | 国家电网公司 | Method and device for verifying pressure relief valve of transformer |
| US9377341B1 (en) * | 2013-04-12 | 2016-06-28 | Joe David Watson | Electronic liquid level sensing device and gauge for liquid-immersed power transformers, reactors and similar equipment |
| CN103683193B (en) * | 2013-12-06 | 2016-03-09 | 国家电网公司 | The transformer microcomputer protection device of automatic adjusting definite value |
| CN105529212A (en) * | 2014-10-23 | 2016-04-27 | 黑龙江宏宇电站设备有限公司 | Oil tank pressure relay protection device and protection method for transformer |
| CN105185542A (en) * | 2015-10-20 | 2015-12-23 | 夏烬楚 | Explosion-proof 75MVA transformer system |
| CN109713640B (en) * | 2019-02-28 | 2019-11-26 | 西安交通大学 | The digital non-ionizing energy loss method of oil-immersed transformer based on pressure characteristic |
-
2019
- 2019-05-07 CN CN201910375876.7A patent/CN110057489B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20080076489A (en) * | 2007-02-16 | 2008-08-20 | 주식회사 한솔테크 | Fault pressure relay for power transformer |
| CN202420748U (en) * | 2011-12-30 | 2012-09-05 | 天威云南变压器股份有限公司 | Monitoring system for oil pressure in transformer oil tank |
| CN204009562U (en) * | 2014-08-27 | 2014-12-10 | 山东电力设备有限公司 | Transformer body travel position on-line monitoring system |
| CN106207969A (en) * | 2016-08-08 | 2016-12-07 | 河南开启电力实业有限公司 | Transformer station's oil-filled transformer on-line monitoring early warning system |
| CN208206204U (en) * | 2018-06-19 | 2018-12-07 | 三峡大学 | Network distribution transformer on-Line Monitor Device based on GPS positioning |
Non-Patent Citations (2)
| Title |
|---|
| 基于压力特征的变压器数字式保护研究;闫晨光、郝治国、张保会;《中国电机工程学报》;20151220(第24期);正文第6405-6411页，图2 * |
| 电力变压器油压监测与保护系统设计;唐玉玲;《仪表技术与传感器》;20091115(第11期);正文第52-54页，图1-3 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110057489A (en) | 2019-07-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110174137B (en) | Monitoring method of transformer monitoring device based on non-electric quantity comprehensive characteristic information | |
| CN110057443B (en) | Transformer online monitoring device and method based on transient acceleration characteristics | |
| CN110018328B (en) | Power transformer on-line monitoring device and method based on transient oil flow characteristics | |
| CN110165778B (en) | Non-electric quantity protection fault recording device and method for oil-immersed power transformer | |
| CN201548633U (en) | Intelligent online monitoring system of transformer | |
| CN100583586C (en) | Unbalanced protection method and device for high-voltage serial connection compensation capacitor group | |
| CN102788645B (en) | Infrared monitoring system for temperature rise of electric connecting point of electrical equipment and monitoring method | |
| CN110057489B (en) | Power transformer online monitoring device and method based on transient oil pressure characteristics | |
| CN110061473B (en) | Digital protection device and method for transformer based on pressure single quantity information | |
| CN202994931U (en) | Lightning arrester state monitoring device based on wireless sensing technology | |
| CN110071481B (en) | Digital gas protection device and method for power transformer | |
| CN106990304A (en) | Power capacitor running status on-line monitoring method based on capacitance | |
| WO2020224537A1 (en) | Transformer digital adaptive protection apparatus and method based on pressure characteristics | |
| CN110086257B (en) | Digital gas protection and oil flow surge monitoring integrated device and method for transformer | |
| CN109470914A (en) | A kind of VFTO signal measurement apparatus | |
| CN105371742A (en) | Bushing tap pulse signal injection method-based transformer winding deformation detection device and method | |
| CN203299307U (en) | Electrical equipment fault detection device | |
| CN104111381A (en) | Dielectric loss on-line monitoring device for 35kV high voltage parallel connection power capacitor group | |
| CN110161357B (en) | Fault recording device and method for pressure relief valve of oil-immersed power transformer | |
| CN203164360U (en) | Transformer device insulation online monitoring system | |
| CN110231523B (en) | Gas protection fault recording device and method for oil-immersed power transformer | |
| CN115808199A (en) | Transformer comprehensive performance test system | |
| CN108303668A (en) | The digitized measurement simulator based on three-phase high-voltage electric energy | |
| CN209605874U (en) | A kind of transformer non-electricity multi-space integrated information synchro measure acquisition device | |
| CN206431221U (en) | A kind of high-tension electricity transformer station high-voltage side bus monitoring system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |