Non-effective grounding voltage transformer and voltage mutual inductance state monitoring method

Abstract

The invention provides a non-effective grounding voltage transformer and a voltage mutual inductance state monitoring method, the non-effective grounding voltage transformer comprises a main voltage transformer and a zero sequence voltage transformer, the main voltage transformer comprises a primary high voltage winding, a secondary low voltage winding and a secondary protection winding, the zero-sequence voltage transformer comprises a zero-sequence primary winding, a zero-sequence secondary winding and a zero-sequence protection winding; a neutral point of the primary high-voltage winding is electrically connected with one end of the zero-sequence primary winding, a neutral point of the secondary low-voltage winding is electrically connected with one end of the zero-sequence secondary winding, and the other ends of the zero-sequence secondary winding and the zero-sequence primary winding are grounded; one end of the secondary protection winding and one end of the zero-sequence protection winding are grounded, the other end of the zero-sequence protection winding is grounded, and the other end of the secondary protection winding is grounded through the current-sensitive resonance elimination resistor; when a power distribution system is disturbed and attempts to cause resonance, the iron core of the zero sequence voltage transformer is rapidly saturated, which is equivalent to that a resistor is connected in series in a loop, so that a large amount of resonance energy is consumed and a resonance elimination effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of power distribution network technology, and more specifically, to a non-effectively grounded voltage transformer and a method for monitoring the condition of the voltage transformer. Background Technology

[0002] In power systems operating with an ungrounded neutral point, ferroresonant overvoltage poses a significant threat to the system. In this mode, Y-connected electromagnetic voltage transformers are used. Under normal operating conditions, the three phases of the PT are essentially balanced, and the neutral point voltage remains relatively stable. However, when system disturbances occur, such as the clearing of a single-phase arcing ground fault, the neutral point potential shifts relative to ground potential. This can lead to severe saturation of the PT core, a decrease in magnetizing inductance, and severe ferroresonant current in the grid. This can result in a large inrush current, burning out the fuse connected in series on the primary side of the electromagnetic voltage transformer or even damaging the transformer itself.

[0003] Currently, the main way to effectively improve the ferroresonance phenomenon is by using a PT with good excitation performance or grounding the neutral point through an arc suppression coil. However, the cost of these two methods is relatively high, and the switching operation process can also cause the PT to resonate. Summary of the Invention

[0004] To facilitate the elimination of PT ferroresonance, this application provides a non-effectively grounded voltage transformer and a method for monitoring the state of the voltage transformer.

[0005] Firstly, this application provides a non-effectively grounded voltage transformer, which adopts the following technical solution: A non-effectively grounded voltage transformer includes a main voltage transformer and a zero-sequence voltage transformer. The main voltage transformer includes a primary high-voltage winding, a secondary low-voltage winding, and a secondary protection winding. The zero-sequence voltage transformer includes a zero-sequence primary winding, a zero-sequence secondary winding, and a zero-sequence protection winding. The neutral point of the primary high-voltage winding is electrically connected to one end of the zero-sequence primary winding, and the other end of the zero-sequence primary winding is grounded. The neutral point of the secondary low-voltage winding is electrically connected to one end of the zero-sequence secondary winding, and the other end of the zero-sequence secondary winding is grounded. One end of the secondary protection winding is grounded to one end of the zero-sequence protection winding, the other end of the zero-sequence protection winding is grounded, and the other end of the secondary protection winding is grounded through a current-sensitive harmonic-suppressing resistor.

[0006] Optionally, a low-voltage relay is connected in parallel with the current-sensitive harmonic-suppressing resistor.

[0007] Optionally, the closing coil of the low-voltage relay is connected in series between the current-sensitive harmonic-suppressing resistor and the output terminal of the protection winding.

[0008] Optionally, a nonlinear resistor module is also connected in parallel to the current-sensitive harmonic-suppressing resistor. The nonlinear resistor module is composed of multiple zinc oxide resistors connected in series and parallel.

[0009] Secondly, this application provides a method for monitoring the condition of a voltage transformer in a non-effectively grounded system, employing the following technical solution: A method for monitoring the condition of a voltage transformer in a non-effectively grounded system, the method comprising: Obtain the current temperature change data of the current-sensitive harmonic-suppressing resistor and the current resonant voltage data on the zero-sequence primary winding; Based on the current temperature change data and the current resonant voltage data, the aging status information of the current-sensitive resistor is calculated and generated; Obtain historical power distribution system current data of the current power distribution system, and calculate and generate an estimated aging coefficient threshold based on the historical power distribution system current data; Based on the aging status information and the estimated aging coefficient threshold, the estimated service life is calculated and generated.

[0010] Optionally, the step of calculating and generating aging status information of the current-sensitive resistor based on the current temperature change data and the current resonant voltage data includes: Obtain the ambient temperature data of the environment in which the current-sensitive harmonic-suppressing resistor is located; Based on the ambient temperature data and the current temperature change data, the resistance temperature rise data is calculated and generated. Based on the current resonant voltage data and the preset standard temperature rise data, a standard temperature rise value is calculated and generated; Based on the standard temperature rise value and resistance temperature rise data, calculate and generate aging status information of the current-sensitive resistor carrying the current aging coefficient.

[0011] Optionally, the step of calculating and generating an estimated aging factor threshold based on the historical power distribution system current data includes: Based on the historical power distribution system current data, the peak current of the power distribution system is selected; Based on the peak current of the power distribution system in the preset resonant voltage prediction data, the corresponding peak resonant voltage value is matched; Based on the peak resonant voltage value, the preset temperature rise threshold, and the standard temperature rise data, a corresponding estimated aging coefficient threshold is generated.

[0012] Optionally, the step of calculating and generating the estimated service life based on the aging state information and the estimated aging coefficient threshold includes: Based on the aging coefficient threshold and the current-sensitive resistor aging status information, the corresponding first and second usage durations are matched in the preset ideal aging data table. The estimated service life is calculated based on the difference between the first usage duration and the second usage duration.

[0013] Thirdly, this application provides a condition monitoring system for voltage transformers in a non-effectively grounded system, employing the following technical solution: A condition monitoring system for a voltage transformer in a non-effectively grounded system, the condition monitoring terminal comprising: The information acquisition module is used to acquire the current temperature change data of the current-sensitive harmonic elimination resistor and the current resonant voltage data on the zero-sequence primary winding; The aging coefficient calculation and processing module is used to calculate and generate aging status information of the current-sensitive resistor based on the current temperature change data and the current resonant voltage data. The aging coefficient matching processing module is used to obtain historical power distribution system current data of the current power distribution system and calculate and generate an estimated aging coefficient threshold based on the historical power distribution system current data. The lifespan estimation module is used to calculate and generate an estimated lifespan based on the aging status information and the estimated aging coefficient threshold.

[0014] In summary, this application includes at least one of the following beneficial technical effects: This application includes a zero-sequence voltage transformer. When a disturbance occurs in the power distribution system and attempts to induce resonance, the voltage on the zero-sequence primary winding, the zero-sequence secondary winding, and the zero-sequence protection winding of the zero-sequence voltage transformer increases, and the iron core of the zero-sequence voltage transformer quickly saturates. At this time, the zero-sequence primary winding and the zero-sequence secondary winding can be equivalent to resistors connected in series in the circuit, thereby consuming a large amount of resonance energy and thus achieving the purpose of eliminating resonance. This application can eliminate ferroresonance and suppress ultra-low frequency oscillation. In addition, it can effectively prevent the secondary protection winding from burning out due to insufficient heat capacity caused by capacitor discharge current. In this application, the aging state of the current-sensitive harmonic-suppressing resistor is determined by the temperature rise during its current operation, thereby facilitating timely replacement and maintenance. Furthermore, based on the historical current data of the power distribution system where the current main voltage transformer is located, the maximum resonant voltage that may occur when a fault occurs in the power distribution system is estimated, which in turn facilitates the estimation of the minimum estimated service life of the current-sensitive harmonic-suppressing resistor and reduces the impact of aging of the current-sensitive harmonic-suppressing resistor. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a circuit diagram of a non-effectively grounded voltage transformer provided in an embodiment of this application.

[0017] Figure 2 This is a schematic flowchart of a state monitoring method for a voltage transformer in a non-effectively grounded system provided in an embodiment of this application.

[0018] Figure 3 This is a system block diagram of a state monitoring system for a voltage transformer in a non-effectively grounded system, provided in an embodiment of this application.

[0019] Explanation of reference numerals in the attached diagram: 11. Primary high-voltage winding; 12. Secondary low-voltage winding; 13. Secondary protection winding; 21. Zero-sequence primary winding; 22. Zero-sequence secondary winding; 23. Zero-sequence protection winding; 201. Information acquisition module; 202. Aging coefficient calculation and processing module; 203. Aging coefficient matching and processing module; 204. Life estimation module; 205. Information filtering module. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the following will be described in conjunction with the appendix. Figure 1-3 The embodiments of the present invention will be described in further detail below.

[0021] This application provides a non-effectively grounded voltage transformer, such as... Figure 1 As shown, it includes the main voltage transformer T and the zero-sequence voltage transformer T0.

[0022] The main voltage transformer T includes a primary high-voltage winding 11, a secondary low-voltage winding 12, and a secondary protection winding 13, wherein signal acquisition is output from the secondary low-voltage winding 12.

[0023] The zero-sequence voltage transformer T0 includes a zero-sequence primary winding 21, a zero-sequence secondary winding 22, and a zero-sequence protection winding 23.

[0024] The three single-phase windings in the primary high-voltage winding 11 are connected in a Y-shape. The neutral point of the primary high-voltage winding 11 is electrically connected to one end of the zero-sequence primary winding 21, and the other end of the zero-sequence primary winding 21 is grounded. The three single-phase windings in the secondary low-voltage winding 12 are connected in a Y-shape. The neutral point of the secondary low-voltage winding 12 is electrically connected to one end of the zero-sequence secondary winding 22, and the other end of the zero-sequence secondary winding 22 is grounded. The secondary protection winding 13 is connected in an open delta configuration. One end of the secondary protection winding 13 is grounded to one end of the zero-sequence protection winding 23, the other end of the zero-sequence protection winding 23 is grounded, and the other end of the secondary protection winding 13 is grounded through the current-sensitive harmonic-suppressing resistor YJ.

[0025] In addition, the non-effectively grounded voltage transformer also includes a low-voltage relay K and a nonlinear resistor module MOV, both of which are connected in parallel to the current-sensitive harmonic-suppressing resistor YJ. The low-voltage relay K is a normally open low-voltage relay K, and its closing coil is connected in series between the current-sensitive harmonic-suppressing resistor YJ and the secondary protection winding 13. The nonlinear resistor module MOV is composed of multiple zinc oxide resistors connected in series and parallel.

[0026] When only a very low current flows through the secondary protection winding 13, the low-voltage relay K remains in the open state. When a current exceeding the closing threshold flows through the secondary protection winding 13, the low-voltage relay K switches from the open state to the closed state, at which point the current-sensitive harmonic-suppressing resistor YJ is connected. When a large current flows through the secondary protection winding 13, the resistance value of the zinc oxide resistor in the nonlinear resistor module MOV decreases, thereby reducing the possibility of the current-sensitive harmonic-suppressing resistor YJ burning out.

[0027] The open delta connection of the secondary protection winding 13 and the zero-sequence protection winding 23 of the zero-sequence voltage transformer T0 are connected in positive polarity. This allows the zero-sequence protection winding 23 to contain a small portion of the zero-sequence voltage of the secondary protection winding 13, resulting in more accurate measurements and avoiding the potential risk of burnout due to insufficient heat capacity of the secondary protection winding 13 caused by capacitor discharge current. Simultaneously, by modifying the design parameters of the zero-sequence voltage transformer T0, the DC resistance and AC excitation impedance can be increased, thereby increasing the heat capacity and effectively suppressing burnout of the zero-sequence voltage transformer T0 caused by ultra-low frequency oscillation overcurrent. Therefore, this application can eliminate ferroresonance and suppress ultra-low frequency oscillations, and also effectively prevent the possibility of burnout due to insufficient heat capacity of the secondary protection winding 13 caused by capacitor discharge current.

[0028] This application also provides a condition monitoring method for a voltage transformer in a non-effectively grounded system. This method can be applied to a condition monitoring system for a voltage transformer in a non-effectively grounded system. The condition monitoring system can consist of a condition monitoring terminal, a main voltage transformer T, a zero-sequence voltage transformer T0, an ADC voltage monitoring module, and a temperature sensor. The execution entity of this method can be the condition monitoring terminal within the condition monitoring system of the voltage transformer in a non-effectively grounded system. This application uses the condition monitoring of the current-sensitive harmonic-suppressing resistor YJ in the voltage transformer as an example for illustration.

[0029] The following will describe the specific implementation methods. Figure 2 The processing flow shown is explained in detail below: Step S101: Obtain the current temperature change data of the current-sensitive harmonic elimination resistor YJ and the current resonant voltage data on the zero-sequence primary winding 21.

[0030] In implementation, the status monitoring terminal uses a temperature sensor to acquire temperature change data of the current-sensitive harmonic elimination resistor YJ within a preset time period, which can be referred to as the current temperature change data. At the same time, the status monitoring terminal uses an ADC voltage monitoring module to acquire the resonant voltage data on the zero-sequence primary winding 21 within a preset time period corresponding to the current temperature change data, which can be referred to as the current resonant voltage data.

[0031] Step S102: Calculate and generate aging status information of the current-sensitive resistor based on the current temperature change data and the current resonant voltage data.

[0032] In implementation, the condition monitoring terminal is pre-loaded with standard temperature rise data. This standard temperature rise data comes from data recorded on the temperature rise versus resonant voltage under a specific laboratory environment, obtained from experiments conducted using the same type of current-sensitive harmonic-suppressing resistor YJ as described in this application. The condition monitoring terminal uses the standard temperature rise data, combined with current temperature change data and current resonant voltage data, to calculate the aging status information of the current-sensitive resistor.

[0033] Specifically, in step S102, the following processing steps also exist, and the operation flow is as follows: Obtain the ambient temperature data of the environment in which the current-sensitive harmonic-suppressing resistor YJ is located; Based on ambient temperature data and current temperature change data, the resistance temperature rise data is calculated and generated. Based on the current resonant voltage data and the preset standard temperature rise data, the standard temperature rise value is calculated and generated. Based on the standard temperature rise value and resistance temperature rise data, calculate and generate aging status information of the current-sensitive resistor carrying the current aging coefficient.

[0034] During implementation, the status monitoring terminal acquires the ambient temperature data of the current-sensitive harmonic elimination resistor YJ within a preset time period prior to the current moment in its working environment.

[0035] Next, the status monitoring terminal subtracts the ambient temperature data at the corresponding moment from the current temperature change data of the current-sensitive harmonic-suppressing resistor YJ to calculate and generate the temperature rise data of the current-sensitive harmonic-suppressing resistor YJ.

[0036] At the same time, the condition monitoring terminal uses the current resonant voltage data to match multiple temperature rise values ​​in the standard temperature rise data, and calculates the standard temperature rise value by averaging the multiple temperature rise values.

[0037] Then, the condition monitoring terminal calculates the actual average temperature rise value by averaging the resistance temperature rise data, and divides the actual average temperature rise value by the standard temperature rise value to calculate the current aging coefficient, thereby generating aging status information of the current-sensitive resistor carrying the current aging coefficient.

[0038] Step S103: Obtain historical power distribution system current data of the current power distribution system, and calculate and generate the estimated aging coefficient threshold based on the historical power distribution system current data.

[0039] In practice, the condition monitoring terminal obtains historical distribution system current data corresponding to the current distribution system where the main voltage transformer T is located from the distribution system network. Then, the condition monitoring terminal matches the historical distribution system current data to determine the corresponding estimated aging system threshold.

[0040] Specifically, in step S103, the following processing steps also exist, and the operation flow is as follows: Based on historical power distribution system current data, the peak current of the power distribution system is selected; Based on the peak current of the power distribution system in the preset resonant voltage prediction data, the corresponding peak resonant voltage value is matched; Based on the peak resonant voltage value, the preset temperature rise threshold, and the standard temperature rise data, the corresponding estimated aging coefficient threshold is generated.

[0041] In implementation, the condition monitoring terminal has pre-set resonant current prediction data. This data reflects the correspondence between the current value of the power distribution system and the resonant voltage value generated when a fault occurs in the power distribution system. The resonant voltage prediction data can be derived from the aggregation and statistics of big data, by statistically aggregating the resonant voltage values ​​under multiple fault conditions and then extrapolating the results.

[0042] The status monitoring terminal first filters out the resonant voltage value corresponding to the peak current of the power distribution system from the historical power distribution system data. This value is referred to as the peak resonant voltage value.

[0043] The condition monitoring terminal then matches the peak resonant voltage value with the corresponding target temperature rise value from the standard temperature rise data. In addition, the condition monitoring terminal is also equipped with a temperature rise threshold. The condition monitoring terminal divides the temperature rise threshold by the target temperature rise value to calculate the estimated aging coefficient threshold.

[0044] Step S104: Calculate and generate the estimated service life based on the aging status information and the estimated aging coefficient threshold.

[0045] During implementation, the condition monitoring terminal is also pre-set with an ideal aging data table, which is used to reflect the relationship between the aging coefficient and the service life of the current-sensitive harmonic elimination resistor YJ.

[0046] The condition monitoring terminal calculates the estimated service life of the current harmonic elimination resistor YJ based on the current aging coefficient and the estimated aging system threshold in the current resistor aging status information.

[0047] Specifically, in step S104, the following processing steps also exist, and the operation flow is as follows: Based on the aging coefficient threshold and the aging status information of the current-sensitive resistor, the corresponding first and second usage times are matched in the preset ideal aging data table. The estimated service life is calculated based on the difference between the first and second usage durations.

[0048] In implementation, the condition monitoring terminal matches the corresponding first and second usage durations in the ideal aging data table using the aging coefficient threshold and the current aging coefficient in the current-sensitive resistor aging status information. Then, the condition monitoring terminal generates the estimated service life by subtracting the second usage duration from the first usage duration.

[0049] In this application, the aging state of the current-sensitive harmonic suppression resistor YJ is determined by the temperature rise during its current operation, thereby facilitating timely replacement and maintenance. Furthermore, based on the historical power distribution system current data of the current main voltage transformer T, the maximum resonant voltage that may occur when a power distribution system fault occurs is estimated, which in turn facilitates the estimation of the minimum estimated service life of the current-sensitive harmonic suppression resistor YJ and reduces the impact of aging on the current-sensitive harmonic suppression resistor YJ.

[0050] This application also discloses a status monitoring system for a voltage transformer in a non-effectively grounded system, including a status monitoring terminal, an ADC voltage monitoring module, and a temperature sensor. The status monitoring terminal includes: Information acquisition module 201 is used to acquire the current temperature change data of current-sensitive harmonic elimination resistor YJ and the current resonant voltage data on zero-sequence primary winding 21; The aging coefficient calculation and processing module 202 is used to calculate and generate aging status information of the current-sensitive resistor based on the current temperature change data and the current resonant voltage data. The aging coefficient matching processing module 203 is used to obtain the historical power distribution system current data of the current power distribution system and calculate and generate the estimated aging coefficient threshold based on the historical power distribution system current data. The lifespan estimation module 204 is used to calculate and generate an estimated lifespan based on aging status information and an estimated aging coefficient threshold.

[0051] Optional, a status monitoring terminal, specifically used for: Information acquisition module 201 is used to acquire ambient temperature data of the environment in which the current-sensitive harmonic elimination resistor YJ is located; The aging coefficient calculation and processing module 202 is used to calculate and generate resistance temperature rise data based on ambient temperature data and current temperature change data. The aging coefficient matching processing module 203 is used to calculate and generate a standard temperature rise value based on the current resonant voltage data and the preset standard temperature rise data. The aging coefficient calculation and processing module 202 is used to calculate and generate aging status information of the current-sensitive resistor carrying the current aging coefficient based on the standard temperature rise value and the resistance temperature rise data.

[0052] Optional, a status monitoring terminal, specifically used for: The information filtering module 205 is used to filter out the peak current of the power distribution system based on historical power distribution system current data. The aging coefficient matching processing module 203 is used to match the corresponding peak resonant voltage value based on the peak current of the power distribution system in the preset resonant voltage estimation data. The aging coefficient calculation and processing module 202 is used to generate the corresponding estimated aging coefficient threshold based on the peak resonant voltage value, the preset temperature rise threshold and the standard temperature rise data.

[0053] Optional, a status monitoring terminal, specifically used for: The aging coefficient matching processing module 203 is used to match the corresponding first usage time and second usage time in the preset ideal aging data table based on the aging coefficient threshold and the current-sensitive resistor aging status information. The lifespan estimation module 204 is used to calculate and generate an estimated lifespan based on the difference between the first usage time and the second usage time.

[0054] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory.

[0055] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

[0056] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A non-active grounded voltage transformer, characterized by: The main voltage transformer comprises a primary high-voltage winding, a secondary low-voltage winding and a secondary protection winding, and the zero-sequence voltage transformer comprises a zero-sequence primary winding, a zero-sequence secondary winding and a zero-sequence protection winding; One end of the zero-sequence primary winding is electrically connected to the neutral point of the primary high-voltage winding, and the other end of the zero-sequence primary winding is grounded; One end of the zero-sequence secondary winding is electrically connected to the neutral point of the secondary low-voltage winding, and the other end of the zero-sequence secondary winding is grounded; One end of the secondary protection winding is grounded, and the other end of the secondary protection winding is grounded through a current-sensitive neutralizing resistor.

2. The non-active grounded voltage transformer according to claim 1, characterized in that: The low-voltage relay is connected in parallel with the current-sensitive neutralizing resistor.

3. The non-active grounded voltage transformer according to claim 2, characterized in that: The closing coil of the low-voltage relay is connected in series between the current-sensitive neutralizing resistor and the output end of the protection winding.

4. The non-active grounded voltage transformer of claim 1, characterized in that: The current-sensitive neutralizing resistor is also connected in parallel with a non-linear resistance module, and the non-linear resistance module is composed of a plurality of zinc oxide resistors connected in series and parallel.

5. A method for monitoring the state of a non-effectively grounded system voltage transformer, applied to the non-effectively grounded voltage transformer of any one of claims 1 to 4, characterized by, The method comprises: obtaining current temperature change data of the current-sensitive neutralizing resistor and current resonant voltage data on the zero-sequence primary winding; generating current-sensitive resistor aging state information according to the current temperature change data and the current resonant voltage data; obtaining historical power distribution system current data of a current power distribution system, and generating an estimated aging coefficient threshold according to the historical power distribution system current data; generating an estimated service life according to the aging state information and the estimated aging coefficient threshold.

6. The method of claim 5, wherein, The method comprises: obtaining environmental temperature data of the environment in which the current-sensitive neutralizing resistor is located; generating resistance temperature rise data according to the environmental temperature data and the current temperature change data; generating a standard temperature rise value according to the current resonant voltage data and a preset standard temperature rise data; generating current-sensitive resistor aging state information carrying a current aging coefficient according to the standard temperature rise value and the resistance temperature rise data.

7. The method of claim 6, wherein, The method comprises: filtering out a power distribution system current peak value according to the historical power distribution system current data; matching a corresponding peak resonant voltage value in preset resonant voltage estimation data according to the power distribution system current peak value; generating a corresponding estimated aging coefficient threshold according to the peak resonant voltage value, a preset temperature rise threshold and the standard temperature rise data.

8. The method of claim 7, wherein, The method comprises: matching a corresponding first service time and a second service time in a preset ideal aging data table according to the aging coefficient threshold and the current-sensitive resistor aging state information; generating an estimated service life according to the difference between the first service time and the second service time.

9. A condition monitoring system for a voltage transformer of a non- solidly grounded system, characterized by The state monitoring terminal comprises: An information acquisition module is configured to acquire current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data of the current temperature variation data ​ ​ ​

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