CN109919390B - Method and device for predicting temperature rise of contact point of power equipment - Google Patents
Method and device for predicting temperature rise of contact point of power equipment Download PDFInfo
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- CN109919390B CN109919390B CN201910199960.8A CN201910199960A CN109919390B CN 109919390 B CN109919390 B CN 109919390B CN 201910199960 A CN201910199960 A CN 201910199960A CN 109919390 B CN109919390 B CN 109919390B
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Abstract
The invention relates to a method and a device for predicting temperature rise of a contact point of power equipment, wherein the method comprises the following steps: acquiring a first temperature rise of a contact point of the power equipment at the beginning of an initial sampling period and a second temperature rise at the end of the initial sampling period, wherein the contact point is the contact position of at least two components of the power equipment; acquiring a time constant of a first-order inertia system of the power equipment; and predicting a third temperature rise of the contact point at the end of the Xth sampling period according to the first temperature rise, the second temperature rise and a time constant, wherein L is a positive integer and is more than or equal to 3, s is a sampling period, and N is a time constant. According to the invention, the temperature rise after the preset time period is predicted by acquiring the temperature rises at the beginning and the end of a sampling period, so that the temperature rise after the preset time period, such as the value after the temperature rise is stable, can be quickly determined, and further, subsequent operations, such as judging whether a contact point has a fault, can be executed through the predicted temperature rise.
Description
Technical Field
The invention relates to the field of power systems, in particular to a method and a device for predicting temperature rise of a contact point of power equipment.
Background
The switch cabinet is an important power transmission and distribution device in an electric power system, so that the operation condition of the switch cabinet needs to be monitored in real time. The switch cabinet generally has various contact points, such as the position where the tulip contact is contacted with the fixed contact, the position where the copper bar is connected with the external device, and the like, and when current flows through the contact points, the contact points generate heat, so that the maximum allowable heat-generating temperature and the maximum allowable temperature rise of the contact points are specified in the national standard. Due to factors such as manufacturing, installation, transportation or long-term operation, the contact points may be oxidized, deformed and loosened, and when the problems occur, the temperature rise of the contact points exceeds a specified range, so that the switch cabinet is damaged. To avoid these problems, it is often necessary to monitor the temperature rise of the contacts on-line. Specifically, when the actual temperature rise is found to exceed the maximum allowable temperature rise, it is determined that the contact point is malfunctioning. The temperature rise here refers to the difference between the temperature of the contact point and the ambient temperature, which is generally obtained by means of a temperature probe placed in the environment.
Because the temperature rise is just gradually stable through a long period of time, if the contact point is detected to break down after the temperature rise is stable, the switch cabinet works for a period of time at the moment, and the service life of the switch cabinet is influenced.
Disclosure of Invention
In view of the above, the present invention provides a method for predicting a temperature rise of a contact point of an electrical device, including:
acquiring a first temperature rise of a contact point of an electric power device at the beginning of an initial sampling period and a second temperature rise at the end of the initial sampling period, wherein the contact point is a contact position of at least two components of the electric power device;
acquiring a time constant of a first-order inertia system of the power equipment;
and predicting a third temperature rise of the contact point at the end of the Xth sampling period according to the first temperature rise, the second temperature rise and the time constant, wherein L is a positive integer and is more than or equal to 3, s is a sampling period, and N is a time constant.
According to the invention, the temperature at the beginning and the end of an initial sampling period is obtained, and the temperature after X sampling periods is predicted, so that the stable temperature rise corresponding to the contact point can be rapidly determined, and further, subsequent operations, such as judging whether the contact point has a fault, are executed according to the predicted temperature rise.
According to the method as described above, optionally, predicting a third temperature rise of the contact point after the X sampling cycles according to the first temperature rise, the second temperature rise and the X comprises:
determining a third temperature rise T of said contact point according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N)
wherein, Δ Kn-1For the first temperature rise, Δ KnIs the second temperature rise.
According to the method as described above, optionally, after predicting a third temperature rise of the contact point at the end of the xth sampling period, the method further comprises:
acquiring a primary current of the power equipment in the initial sampling period;
and determining whether the contact point has a fault according to the third temperature rise and the primary current.
The temperature rise of the contact point of the power equipment is predicted, the product value of the contact resistance and the thermal resistance of the contact point is determined through the temperature rise, and whether the contact point has a fault or not is determined through the product value. Like this, can confirm whether the contact point breaks down in the short time after power equipment begins work, and then guarantee power equipment's life-span and relevant staff's safety.
According to the method as described above, optionally, determining whether the contact point is malfunctioning according to the third temperature rise and the primary current comprises:
determining a product of a contact resistance and a thermal resistance of the contact point according to the following formula:
T＝Iw2*R*Rθ
wherein Iw represents the primary current, R represents a contact resistance of the contact point, and R θ represents a thermal resistance of the contact point;
and if the product of the contact resistance and the thermal resistance of the contact point is greater than a preset threshold value, determining that the contact point has a fault.
The product of the contact resistance and the thermal resistance reflects the connection state of the power equipment system itself, which is independent of the input and should be stable. Whether the contact point has a fault or not is determined by the product of the contact resistance and the thermal resistance of the contact point, and the accuracy is good.
According to the method as described above, optionally, the primary current is an average value of the primary current in the initial sampling period. Because the primary current may change in real time, the average value of the primary current in the whole sampling period is used as the primary current of the power equipment in the period, and the accurate value of the primary current can be obtained as much as possible.
The present invention also provides a device for predicting a temperature rise of a contact point of an electric power apparatus, comprising:
a first acquiring unit, configured to acquire a first temperature rise at a start time and a second temperature rise at an end time of a contact point of an electrical device at an initial sampling period, where the contact point is a contact position of at least two components of the electrical device;
a second acquisition unit for acquiring a time constant of a first-order inertial system of an electric power device; and a prediction unit for predicting a third temperature rise of the contact point at the end of an xth sampling period, where L is a positive integer and L ≧ 3, s is a sampling period, and N ═ s ═ time constant, based on the first temperature rise, the second temperature rise, and the time constant.
According to the invention, the temperature after the preset time period is predicted by acquiring the temperature at the beginning and the end of a sampling period, so that the temperature rise after X periods can be rapidly determined, the temperature rise after the X periods can be regarded as the stable temperature rise, and further, subsequent operations, such as judging whether the contact point has a fault, are executed according to the predicted temperature rise.
According to the apparatus as described above, optionally, the prediction unit is specifically configured to:
determining a third temperature rise T of said contact point according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N)
wherein, Δ Kn-1For the first temperature rise, Δ KnIs the second temperature rise.
The apparatus as described above, optionally, further comprising:
a third obtaining unit, configured to obtain a primary current of the power device in the initial sampling period;
a determination unit for determining whether the contact point is faulty or not based on the third temperature rise and the primary current.
The temperature rise of the contact point of the power equipment is predicted, the product value of the contact resistance and the thermal resistance of the contact point is determined through the temperature rise, and whether the contact point has a fault or not is determined through the product value. Like this, can confirm whether the contact point breaks down in the short time after power equipment begins work, and then guarantee power equipment's life-span and relevant staff's safety.
According to the apparatus as described above, optionally, the determining unit is specifically configured to:
determining a product of a contact resistance and a thermal resistance of the contact point according to the following formula:
T＝Iw2*R*Rθ
wherein Iw represents the primary current, R represents a contact resistance of the contact point, and R θ represents a thermal resistance of the contact point;
and if the product of the contact resistance and the thermal resistance of the contact point is greater than a preset threshold value, determining that the contact point has a fault.
The product of the contact resistance and the thermal resistance reflects the connection state of the power equipment system itself, which is independent of the input and should be stable. Whether the contact point has a fault or not is determined by the product of the contact resistance and the thermal resistance of the contact point, and the accuracy is good.
According to the apparatus as described above, optionally, the primary current is an average value of the primary current in the initial sampling period. Because the primary current may change in real time, the average value of the primary current in the whole sampling period is used as the primary current of the power equipment in the period, and the accurate value of the primary current can be obtained as much as possible.
The present invention further provides a device for predicting a temperature rise of a contact point of an electric power apparatus, comprising:
at least one memory for storing instructions;
at least one processor configured to perform the method of predicting temperature rise of a contact point of an electrical device of any of the preceding claims in accordance with instructions stored in the memory.
The present invention further provides a readable storage medium having stored therein machine readable instructions, which when executed by a machine, perform the method of predicting temperature rise of a contact point of an electrical power device as set forth in any one of the preceding claims.
Drawings
The foregoing and other features and advantages of the invention will become more apparent to those skilled in the art to which the invention relates upon consideration of the following detailed description of a preferred embodiment of the invention with reference to the accompanying drawings, in which:
fig. 1 is a schematic flowchart of a method for predicting a temperature rise of a contact point of a switchgear according to an embodiment of the present invention.
Fig. 2 is a schematic flow chart of a method for predicting temperature rise of a contact point of a switch cabinet according to another embodiment of the invention.
Fig. 3 is a schematic structural diagram of an apparatus for predicting a temperature rise of a contact point of a switchgear according to still another embodiment of the present invention.
Fig. 4 is a schematic structural diagram of an apparatus for predicting a temperature rise of a contact point of a switchgear according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by referring to the following examples.
The power equipment of the invention can be a switch cabinet or a transformer, and of course, can also be other equipment which can adopt the method of the invention. The contact point of the power device may be a contact position of two locations. The following description will specifically describe a switchgear as an example.
The inventor has found that the load of the switch cabinet is related to the primary current, the larger the load, the larger the primary current, the smaller the load, and the smaller the primary current. In addition, the primary current affects the temperature rise of each contact point. As the primary current is accumulated, the temperature rise gradually rises and is finally maintained at a fixed value. This process may last for a long period of time, at least 8-9 hours. Namely, the temperature rise at the current time point is determined by the current accumulation of 8-9 hours of the university before. On the other hand, the current of one time before 8-9 hours has a negligible effect on the current temperature rise of the contacts. If after the temperature rise is stabilized, it is determined whether the contact point of the switchgear has failed according to the stabilized temperature rise, the switchgear may have been operating in the fault state for a period of time, which may affect the life of the switchgear.
Example one
The embodiment provides a method for predicting the temperature rise of a contact point of a switch cabinet, and the execution main body is a device for predicting the temperature rise of the contact point of the switch cabinet. The device can be integrated in a temperature measuring sensor, a computer or a relay, and can also be independently arranged, and the details are not repeated.
Fig. 1 is a schematic flow chart of a method for predicting temperature rise of a contact point of a switch cabinet according to the present embodiment. The method comprises the following steps:
The initial sampling period is a sampling period corresponding to the first temperature rise and the second temperature rise, and the initial sampling period is not necessarily the 1 st sampling period for actually sampling. The duration of the sampling period can be set according to actual needs, and is 20-30 minutes, for example. Both the first and second temperature increases may be obtained by means of a temperature sensor, which may be mounted at or near the contact point. The contact point of the switch cabinet is the contact position of at least two components, for example, the contact position of the moving contact and the static contact, the contact position of the copper bar and the sleeve, and the like, that is, the contact point may be the contact point of the switch cabinet or the bus contact point, which is not described herein again.
The temperature rise at the contact point refers to the difference between the current temperature at the contact point and the ambient temperature.
The first-order inertia system refers to the response relation between the primary current and the temperature rise. In general, if the primary current is constant and the sampling period reaches a time constant of 3-5 times, the temperature rise should reach almost a steady value. Of course, the primary current of all sampling periods within 8-9 hours can be sampled, and the sampling period can be determined according to actual needs. The time constant of this first order inertial system is known in advance from the parameters of the system, for example 100 minutes.
The step 102 and the step 101 have no execution sequence, and may be executed sequentially or simultaneously.
And 103, predicting a third temperature rise of the contact point at the end of the Xth sampling period according to the first temperature rise, the second temperature rise and a time constant, wherein X is [ LN ], L is a positive integer and is more than or equal to 3, s is a sampling period, and N is a time constant.
Since a temperature rise of 3-5 times of the time constant can reach a certain stable value in general, the value range of L is further 3-5 optionally. [] The rounding is expressed, and can be rounded up or rounded down according to actual needs. A sampling period represents the length of time corresponding to a sampling period, i.e. the time constant of the initial sampling period. In practice, N can be determined to be a positive integer by setting s, for example, the time constant is 100 minutes, s can be 25 minutes, and thus N is 4. Assuming that L is 5, X is 20, which corresponds to 500 minutes, i.e. 8 hours or more.
In this embodiment, a first predicted temperature rise at the end of the next sampling period may be determined according to the first temperature rise and the second temperature rise, a second predicted temperature rise at the end of the next sampling period may be determined according to the second temperature rise and the first predicted temperature rise, a third predicted temperature rise at the end of the next sampling period may be determined again according to the first predicted temperature rise and the second predicted temperature rise, and the above steps are repeated until a third temperature rise of the contact point at the end of the xth sampling period is determined. Specifically, the temperature rising trend of the next sampling period can be determined according to the temperature rising trends of the first temperature rise and the second temperature rise. This third temperature rise can be considered as the predicted stable temperature rise corresponding to the contact point.
Specifically, for example, the third temperature rise T of the contact point may be determined according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N) Wherein, Δ Kn-1Is the first temperature rise, Δ KnA second temperature rise.
The present invention may repeat steps 101 through 103. For example, the steps 101 to 103 are repeatedly executed every 1 minute, so that the temperature rise after the corresponding preset time period can be always predicted, and the real-time monitoring of the temperature rise of the contact point of the switch cabinet is realized. More specifically, in the sampling process, steps 101 to 103 are repeatedly performed from one sampling period, where n represents the nth sampling period, Δ KnFor the temperature rise, Δ K, corresponding to the nth sampling periodn-1For the temperature rise corresponding to the (n-1) th sampling period, any one (n-1) th sampling period can be regarded as the initial sampling period of the invention, and then the subsequent steps are executed to continuously preset the temperature rise of the contact point of the switch cabinet, and further monitor the temperature rise.
The invention has many other ways to determine the predicted temperature rise at the end of each sampling period, which are not described herein again.
According to the invention, the temperature rise at the beginning and at the end of an initial sampling period is obtained, and the temperature after X sampling periods is predicted, so that the stable temperature rise corresponding to the contact point can be quickly determined, and further, subsequent operations, such as judging whether the contact point has a fault, are executed through the predicted temperature rise.
Example two
The present embodiment further provides a supplementary description of the method for predicting the temperature rise of the contact point of the switch cabinet in the first embodiment. Fig. 2 is a schematic flow chart of a method for predicting the temperature rise of the contact point of the switch cabinet according to the embodiment. The method comprises the following steps:
This step is identical to step 101 and will not be described herein.
This step is identical to step 102 and will not be described herein.
And step 203, predicting a third temperature rise of the contact point at the end of the Xth sampling period according to the first temperature rise, the second temperature rise and a time constant, wherein L is a positive integer and is more than or equal to 3, s is a sampling period, and N is a time constant.
This step is identical to step 103 and will not be described herein.
The primary current of the present embodiment refers to a current on the high voltage side. In the initial sampling period, the current may be collected once every other period, for example, the initial sampling period is 30 minutes, the current may be collected once every 1 minute, and the average value of all the collected currents is used as the primary current of the switch cabinet in the initial sampling period. Because the primary current may change in real time, the average value of the primary current in the whole sampling period is used as the primary current of the switch cabinet in the period, and the accurate value of the primary current can be obtained as much as possible. Of course, the primary current at the beginning or the primary current at the end of the initial sampling period may also be used as the primary current of the switch cabinet, which may be specifically selected according to actual needs and is not described herein.
And step 205, determining whether the contact point has a fault according to the third temperature rise and the primary current.
For example, the product of the contact resistance and the thermal resistance of the contact point is determined according to the following formula:
T＝Iw2*R*Rθ
where Iw represents the primary current, R represents the contact resistance of the contact point, and R θ represents the thermal resistance of the contact point.
Specifically, for example, if the target parameter is greater than the sum of the product of the contact resistance and the thermal resistance of the contact point in the normal contact state and a preset error, that is, the target parameter is R × R θ + R, where R is the contact resistance, R θ is the thermal resistance, and R is the preset error, it indicates that the target parameter is too large, and the contact point fails. R here can be set according to actual needs, and is not described in detail here.
The product of the contact resistance and the thermal resistance reflects the connection state of the switch cabinet system itself, which is independent of the input and should remain stable. Whether the contact point has a fault or not is determined by the product of the contact resistance and the thermal resistance of the contact point, and the accuracy is good.
The inventor has found that the load of the switch cabinet is related to the primary current, the larger the load, the larger the primary current, the smaller the load, and the smaller the primary current. In addition, the primary current affects the temperature rise of each contact point. The temperature rise here refers to the difference between the temperature of the contact point and the ambient temperature. For example, if the temperature of the contact point is 35 ℃ and the ambient temperature is 25 ℃, the temperature rise is 10 ℃. If the primary current remains constant, the temperature rise will stabilize at a fixed value after about 8-9 hours. In short, the current temperature rise at the contact point is determined by the current accumulation of about 8-9 a before. On the other hand, the current of one time before 8-9 hours has a negligible effect on the current temperature rise of the contacts. Therefore, considering the relationship between the primary current and the temperature rise of the contact point within 8 to 9 hours, not only can the result be made accurate, but also the calculation amount can be reduced. In addition, when the contact point is in poor contact, loose, or the like, the contact resistance of the contact point changes, generally becoming large, far exceeding the normal range. Accordingly, the temperature rise will be large. Based on the above, whether the contact point is malfunctioning can be determined by determining the thermal resistance of the contact point and the magnitude of the change in the electrical resistance.
According to the embodiment, the temperature rise of the contact point of the switch cabinet is predicted, the product value of the contact resistance and the thermal resistance of the contact point is determined through the temperature rise, and whether the contact point has a fault or not is determined through the product value. Like this, can determine whether the contact point breaks down in the short time after cubical switchboard begins work, and then guarantee the life-span of cubical switchboard and relevant staff's safety.
EXAMPLE III
The present embodiment provides an apparatus for predicting a temperature rise of a contact point of a switchgear, which is used to perform the method of predicting a temperature rise of a contact point of a switchgear of the first embodiment.
Fig. 3 is a schematic structural diagram of the device for predicting the temperature rise of the contact point of the switch cabinet according to the embodiment. The apparatus comprises a first acquisition unit 301, a second acquisition unit 302 and a prediction unit 303.
The first obtaining unit 301 is configured to obtain a first temperature rise of a contact point of the switch cabinet at the beginning of an initial sampling period and a second temperature rise at the end of the initial sampling period, where the contact point is a contact position of at least two components of the switch cabinet; the first determination unit 302 is configured to obtain a time constant of a first-order inertial system of a switch cabinet; the predicting unit 303 is configured to predict a third temperature rise of the contact point at the end of the xth sampling period according to the first temperature rise, the second temperature rise, and a time constant, where L is a positive integer and L is greater than or equal to 3, s is a sampling period, and N is a time constant.
Optionally, the prediction unit 303 is specifically configured to:
determining a third temperature rise T of the contact point according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N)
wherein, Δ Kn-1Is the first temperature rise, Δ KnA second temperature rise.
The working method of each unit of this embodiment is the same as that of the previous embodiment, and is not described herein again.
According to the invention, the temperature rise after the preset time period is predicted by acquiring the temperature rises at the beginning and the end of a sampling period, so that the temperature rise after the preset time period, such as the value after the temperature rise is stable, can be quickly determined, and further, subsequent operations, such as judging whether a contact point has a fault, can be executed through the predicted temperature rise.
Example four
This embodiment further supplements the device for predicting the temperature rise of the contact point of the switch cabinet in the third embodiment.
Fig. 4 is a schematic structural diagram of the device for predicting the temperature rise of the contact point of the switch cabinet according to the embodiment. The apparatus comprises a third acquisition unit 401 and a determination unit 402 in addition to the first acquisition unit 301, the second acquisition unit 302 and the prediction unit 303 shown in fig. 3.
The third obtaining unit 401 is configured to obtain a primary current of the switch cabinet in an initial sampling period; the third determination unit 402 is configured to determine whether the contact point is faulty or not according to the third temperature rise and the primary current.
Optionally, the determining unit 402 is specifically configured to:
the product of the contact resistance and the thermal resistance of the contact point is determined according to the following formula:
T＝Iw2*R*Rθ
wherein Iw represents the primary current, R represents the contact resistance of the contact point, and R θ represents the thermal resistance of the contact point;
if the product of the contact resistance and the thermal resistance of the contact point is greater than a preset threshold value, determining that the contact point has a fault;
optionally, the primary current is an average value of the primary current in the initial sampling period.
Optionally, the preset threshold is a sum of a product of a contact resistance and a thermal resistance of the contact point in a normal contact state and a preset error.
The working method of each unit of this embodiment is the same as that of the previous embodiment, and is not described herein again.
According to the embodiment, the temperature rise of the contact point of the switch cabinet is predicted, the product value of the contact resistance and the thermal resistance of the contact point is determined through the temperature rise, and whether the contact point has a fault or not is determined through the product value. Like this, can determine whether the contact point breaks down in the short time after cubical switchboard begins work, and then guarantee the life-span of cubical switchboard and relevant staff's safety.
The invention also provides another device for predicting the temperature rise of the contact point of the switch cabinet, which comprises at least one memory and at least one processor. Wherein the memory is to store instructions. The processor is configured to execute the method for predicting the temperature rise of the contact point of the switch cabinet according to the instructions stored in the memory.
Embodiments of the present invention also provide a readable storage medium. The readable storage medium has stored therein machine readable instructions which, when executed by a machine, perform the method of predicting temperature rise of a contact point of a switchgear as described in any of the preceding embodiments.
The readable medium has stored thereon machine readable instructions which, when executed by a processor, cause the processor to perform any of the methods previously described. In particular, a system or apparatus may be provided which is provided with a readable storage medium on which software program code implementing the functionality of any of the embodiments described above is stored and which causes a computer or processor of the system or apparatus to read and execute machine-readable instructions stored in the readable storage medium.
In this case, the program code itself read from the readable medium can realize the functions of any of the above-described embodiments, and thus the machine-readable code and the readable storage medium storing the machine-readable code form part of the present invention.
Examples of the readable storage medium include floppy disks, hard disks, magneto-optical disks, optical disks (e.g., CD-ROMs, CD-R, CD-RWs, DVD-ROMs, DVD-RAMs, DVD-RWs, DVD + RWs), magnetic tapes, nonvolatile memory cards, and ROMs. Alternatively, the program code may be downloaded from a server computer or from the cloud via a communications network.
It will be understood by those skilled in the art that various changes and modifications may be made in the above-disclosed embodiments without departing from the spirit of the invention. Accordingly, the scope of the invention should be determined from the following claims.
It should be noted that not all steps and units in the above flows and system structure diagrams are necessary, and some steps or units may be omitted according to actual needs. The execution order of the steps is not fixed and can be adjusted as required. The apparatus structures described in the above embodiments may be physical structures or logical structures, that is, some units may be implemented by the same physical entity, or some units may be implemented by a plurality of physical entities, or some units may be implemented by some components in a plurality of independent devices.
In the above embodiments, the hardware unit may be implemented mechanically or electrically. For example, a hardware unit or processor may comprise permanently dedicated circuitry or logic (such as a dedicated processor, FPGA or ASIC) to perform the corresponding operations. The hardware units or processors may also include programmable logic or circuitry (e.g., a general purpose processor or other programmable processor) that may be temporarily configured by software to perform the corresponding operations. The specific implementation (mechanical, or dedicated permanent, or temporarily set) may be determined based on cost and time considerations.
While the invention has been shown and described in detail in the drawings and in the preferred embodiments, it is not intended to limit the invention to the embodiments disclosed, and it will be apparent to those skilled in the art that various combinations of the code auditing means in the various embodiments described above may be used to obtain further embodiments of the invention, which are also within the scope of the invention.
Claims (10)
1. A method of predicting a temperature rise of a contact point of an electrical device, comprising:
acquiring a first temperature rise of a contact point of an electric power device at the beginning of an initial sampling period and a second temperature rise at the end of the initial sampling period, wherein the contact point is a contact position of at least two components of the electric power device;
acquiring a time constant of a first-order inertia system of the power equipment;
predicting a third temperature rise of the contact point at the end of the Xth sampling period according to the first temperature rise, the second temperature rise and the time constant, wherein L is a positive integer and is more than or equal to 3, s is a sampling period, and N is the time constant; predicting a third temperature rise of the contact point after the X sampling cycles according to the first temperature rise, the second temperature rise and the X includes:
determining a third temperature rise T of said contact point according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N)
wherein, Δ Kn-1For the first temperature rise, Δ KnIs the second temperature rise.
2. The method of claim 1, further comprising, after predicting a third temperature rise of the contact point at the end of the xth sampling period:
acquiring a primary current of the power equipment in the initial sampling period;
and determining whether the contact point has a fault according to the third temperature rise and the primary current.
3. The method of claim 2, wherein determining whether the contact point is malfunctioning based on the third temperature rise and the primary current comprises:
determining a product of a contact resistance and a thermal resistance of the contact point according to the following formula:
T＝Iw2*R*Rθ
wherein Iw represents the primary current, R represents a contact resistance of the contact point, and R θ represents a thermal resistance of the contact point;
and if the product of the contact resistance and the thermal resistance of the contact point is greater than a preset threshold value, determining that the contact point has a fault.
4. The method of claim 3, wherein the primary current is an average of primary currents during the initial sampling period.
5. An apparatus for predicting a temperature rise of a contact point of an electric power device, comprising:
a first acquiring unit, configured to acquire a first temperature rise at a start time and a second temperature rise at an end time of a contact point of an electrical device at an initial sampling period, where the contact point is a contact position of at least two components of the electrical device;
a second acquisition unit for acquiring a time constant of a first-order inertial system of an electric power device;
a prediction unit for predicting a third temperature rise of the contact point at the end of an xth sampling period, where L is a positive integer and L ≧ 3, s is a sampling period, and N ═ s ═ time constant, based on the first temperature rise, the second temperature rise, and the time constant; the prediction unit is specifically configured to:
determining a third temperature rise T of said contact point according to the following formula:
T＝(ΔKn-ΔKn-1*e-1/N)/(1-e-1/N)
wherein, Δ Kn-1For the first temperature rise, Δ KnIs the second temperature rise.
6. The apparatus of claim 5, further comprising:
a third obtaining unit, configured to obtain a primary current of the power device in the initial sampling period;
a determination unit for determining whether the contact point is faulty or not based on the third temperature rise and the primary current.
7. The apparatus according to claim 6, wherein the determining unit is specifically configured to:
determining a product of a contact resistance and a thermal resistance of the contact point according to the following formula:
T＝Iw2*R*Rθ
wherein Iw represents the primary current, R represents a contact resistance of the contact point, and R θ represents a thermal resistance of the contact point;
and if the product of the contact resistance and the thermal resistance of the contact point is greater than a preset threshold value, determining that the contact point has a fault.
8. The apparatus of claim 7, wherein the primary current is an average of primary currents in the initial sampling period.
9. An apparatus for predicting a temperature rise of a contact point of an electric power device, comprising:
at least one memory for storing instructions;
at least one processor configured to execute the method of predicting temperature rise of a contact point of a power device of any of claims 1-4 in accordance with instructions stored by the memory.
10. Readable storage medium, in which machine readable instructions are stored, which when executed by a machine, perform the method of predicting the temperature rise of a contact point of an electrical power device according to any one of claims 1-4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
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| CN103854446B (en) * | 2014-03-14 | 2016-06-29 | Abb技术有限公司 | A kind of dynamic temperature rise diagnostic alarms method and apparatus of high-tension switch cabinet |
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| CN108957304B (en) * | 2018-04-09 | 2020-09-22 | 西安工程大学 | Current-carrying fault prediction method for circuit breaker |
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