RU2361309C1 - Device to estimate transformer serviceability proceeding from transformer residual life - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to instrumentation and can be used to forecast the transformer residual life, calculate reliability proceeding from residual life and determine time before transformer failure. The proposed device incorporates a measuring component, memory components, as well as data processing and display components. It works on the principle that proceeds from the dependence of transformer used-up life upon the temperature of most heated point, i.e.

where R₀ is the transformer life used-up per unit time, at rated temperature of most heat point ϑ₀; R_i is the actual transformer life used-up per unit time, at temperature of most heat point ϑ_i, ϑ_i is the actual temperature of most heated point of the transformer; °C; Δϑ is the absolute departure of the most heated point temperature, °C; ϑ₀ is the rated temperature of the said point °C.

EFFECT: control over serviceability by continuous calculation of its used-up life, revealing time whereat transformer should be taken out of commission and transferred for repair to prevent emergent conditions.

1 dwg

Description

The invention relates to the field of measurement technology and can be used to predict the residual life of the power transformer, calculate reliability by the residual resource and determine the time before the failure of the power transformer.

The known device "Device for monitoring the technical condition of the diagnostic object by the residual resource", which allows you to control the technical condition of the diagnostic object by fixing the number of the failed diagnostic element, calculating the reliability of the entire device and predicting the failure number of the next element (RF patent No. 2279703, 2004).

The above device is the closest in technical essence to the claimed invention. It contains start-up control sensors, an OR element block, an electronic key, a failed element registration unit, a time sensor, a digital-to-analog converter, variable and reference voltage generators, a trigger, an OR element, a counter, a residual resource registration unit, a register block, a decoder, and a reliability calculation unit devices taking into account the residual resource, the unit for ranking failures by the residual resource, the decision block for choosing the failed element, the registration blocks of the failed element. The disadvantage of this device is the inability to determine the residual resource before the failure of a functional element.

The aim of the invention is the expansion of functionality due to automated accounting of factors that reduce the resource, calculating the worked resource and making decisions on the forecast of the further functioning of the power transformer.

This goal is achieved by the fact that in the structural diagram of the inventive device shown in the drawing, a temperature sensor 2, an analog-to-digital converter 3, an electronic key 4, a shaper of time intervals 5, a control device 6, read-only memory 7, a memory unit 8, are introduced a device 9, a comparison device 10, a setter of values of regulatory resources 11, a logical device 12, a digital-to-analog converter 13 and an output signal generating device 14. A temperature sensor 2, which the device’s progress is located at a predetermined most heated point of the transformer 1. The output of the temperature sensor 2 is connected to the input of the analog-to-digital converter 3. The output of the analog-to-digital converter 3 is connected to the input of the electronic key 4. The output of the time interval shaper 5 is connected to the second input of the electronic key 4. The output of the electronic key 4 is connected to the input of a read-only memory device 7, the output of which is connected to the first input of the computing device 9. The output of the computing device 9 connected to the first input of the memory unit 8. The first output of the memory unit 8 is connected to the second input of the computing device 9, and the second output of the memory unit 8 is connected to the first input of the comparison device 10. The output of the setpoint values of the regulatory resources 11 is connected to the second input of the comparison device 10. The output comparison device 10 is connected to the first input of the logical device 12. The output of the logical device 12 is connected to the input of the digital-to-analog converter 13. The output of the digital-to-analog converter 13 is connected to the input of the driver the output signal 14, the output of which is a common output of the claimed device. The outputs of the control device 6 are connected with the second inputs of the temperature sensor 2, the memory unit 8, the setpoint values of the regulatory resources 11, the logical device 12 and the input of the shaper time intervals 5.

The device operates as follows. Temperature sensor 2 continuously measures the temperature of the most heated point of the transformer. While the electronic key 4 is in the closed state, the signal from the sensor 2, converted into an analog-to-digital converter 3, does not enter the read-only memory 7. The time interval generator 5 generates a pulse arriving at the electronic key 4, opening it. Thus, the shaper of time intervals 5 forms a step for measuring temperature per unit time. The signal corresponding to the measured temperature ϑ _i , from the analog-to-digital converter 3 is supplied to a permanent memory 7. In the constant memory 7 are recorded the temperature values of the most heated point of the transformer and the corresponding values of the actual worked resource, calculated by the formula [1]

where R ₀ is the standard resource of the transformer, worked out per unit of time at the nominal value of the temperature of the most heated point ϑ ₀ , in named units;

R _i - the actual resource of the transformer, worked out per unit of time at the temperature of the most heated point ϑ _i , in named units;

ϑ _i is the actual temperature value of the most heated point of the transformer, ° С;

Δϑ is the absolute deviation of the temperature of the most heated point, ° C;

ϑ ₀ - nominal value of the temperature of the most heated point, ° С.

. Если

The value of the actual activated resource of the transformer at the measured temperature of the most heated point R _i enters the computing device 9. At the same time, the value of the actual actual resource of the transformer calculated for the previous measurement step R _{i-1 is} received from the memory unit 8 to the computing device 9. In this case, the memory is reset, and the summed value of the actual worked resource of the transformer R _{i + l} = R _i + R _{i-1 is} recorded in the memory unit. From the memory unit 8, the value of R _{i + 1} enters the comparison device 10, where it is compared with the values of the worked resources corresponding to the operating time before carrying out maintenance and repair during operation of the transformer in standard conditions

. If

...

,

,

where k <1 is a coefficient taking into account the time taken to make a decision and its implementation, the signal from the comparison device 10 through the logic device 12 and the digital-to-analog converter 13 is supplied to the output signal generating device 14, which gives a signal about the need for maintenance of the transformer. If

...

,

,

then there is no signal.

Thus, the inventive device allows you to control the technical condition of the transformer by continuously calculating the consumed resource of the transformer taking into account the intensity of its operation (changing the temperature of the most heated point), make timely decisions on this or that type of service, and most importantly monitor the moment at which the equipment is necessary remove from service and send for repair, thereby preventing emergencies.

Information sources

1. Engineer's reference book on adjustment, improvement of technology and operation of power plants and networks. Centralized and autonomous power supply of facilities, workshops, crafts, enterprises and industrial complexes / Edited by A.N. Nazarychev, Infra-Engineering, 2006

2. Patent for invention No. 2279703, 2004 - prototype.

Claims (1)

A device for assessing the technical condition of the transformer by the residual resource, containing a comparison device, a digital-to-analog converter, an electronic key, characterized in that it has the purpose of expanding the functionality by automatically taking into account factors that reduce the resource, calculating the worked resource and deciding on the prediction of further functioning of the power transformer, temperature sensor, analog-to-digital converter, shaper of time intervals, constant storage introduced a sensing device, a computing device, a memory unit, a setter of normative resource values, a logic device, an output signal shaper, while the temperature sensor, which is the input of the device, is located at a predetermined most heated point of the transformer being evaluated, the output of the temperature sensor is connected to the input of an analog-to-digital converter , the output of the analog-to-digital converter is connected to the input of the electronic key, the output of the shaper of time intervals is also connected to the input of the electronic key, the output of the electronic key is connected to the input of a read-only memory device, the output of which is connected to the first input of the computing device, the output of the computing device is connected to the first input of the memory unit, the first output of which is connected to the second input of the computing device and the first input of the comparison device, the output of the value setter regulatory resources associated with the second input of the comparison device, the output of the comparison device is connected with the first input of the logical device, the output of the logical device It is connected to the input of the digital-to-analog converter, the output of the digital-to-analog converter is connected to the input of the output driver, the output of which is the common output of the inventive device, the outputs of the control device are connected to the second inputs of the temperature sensor, memory unit, setpoint of normative resources, logic device and the input of the driver.