High-thrust vibrating table moving coil double-helix coupling temperature rise restraining and monitoring method

Abstract

The invention discloses a high-thrust vibrating table moving coil double-helix coupling temperature rise suppression and monitoring method, which is characterized in that two strands of hollow enameled wires are wound into an inner layer and an outer layer according to the same spiral direction to form a tightly attached double-layer moving coil winding structure, and the double-layer moving coil winding adopts a parallel power supply mode; temperature sensors are uniformly arranged on an outer-layer moving coil winding from a water inlet to a water outlet, a temperature sensor is arranged at a water outlet of an inner-layer moving coil winding, cooling water flow and driving current are considered, and a moving coil winding temperature distribution function is obtained through fitting by adopting functions reflecting different temperature rise change rates. According to the invention, the driving current of the moving coil is reduced to half of that of a traditional mode, the temperature rise of the moving coil of the high-thrust vibration table is greatly inhibited, the temperature distribution condition of the double-layer driving coil is comprehensively monitored, and the performance and the use safety of the high-thrust electric vibration table can be remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of vibration tables, and in particular to a method for suppressing and monitoring temperature rise of a double-helix coupling of a dynamic coil of a large-thrust vibration table. Background Art

[0002] The electric vibration table is a mechanical environment simulation test equipment, which is mainly used to simulate the vibration dynamic environment to which the test piece is subjected, to test the reliability and durability of the test piece in such a vibration dynamic environment, and to provide support for the structural improvement design of the test piece. Therefore, it is widely used in the fields of aviation, aerospace, weapons, ships, etc. The electric vibration table works according to the law of electromagnetic induction. When an alternating current is input to an energized coil in a constant magnetic field, the coil will be subjected to an electromagnetic force related to the current size and the magnetic field strength, thereby generating the desired exciting force. As the test piece gradually develops in the direction of large-scale, the thrust demand of the vibration table is also gradually increasing.

[0003] At present, the mainstream electric vibration tables on the market generally adopt the single-layer coil winding method. The demand for high thrust has led to a significant increase in the current of the driving coil. According to traditional design experience, theoretically, the driving current of the dynamic coil under a thrust of 60t is about 6500A, and the corresponding driving current is about 10000A when the thrust is increased to 100t. Such a large current will generate huge heat on the dynamic coil, requiring an additional high-power water cooling system for cooling, which limits the development process of high-thrust vibration tables. Therefore, how to effectively reduce the heat generated by the dynamic coil drive of the high-thrust vibration table and thus suppress the temperature rise of the dynamic coil during use is one of the key issues that need to be solved urgently.

[0004] At the same time, during the use of high-thrust vibration tables, the real-time temperature of a certain position on the dynamic coil is generally measured by pre-embedded thermocouple measuring points on the dynamic coil, and the temperature of this point is used to indicate the temperature of the entire drive coil. However, due to the difference in cooling effects on different parts of the dynamic coil, there are differences in temperature distribution along the dynamic coil. This method has a large measurement error and is difficult to reflect the temperature conditions of other parts of the dynamic coil. It often causes inaccurate dynamic coil temperature monitoring, affects the evaluation of the dynamic coil status of the vibration table, and poses certain operational safety risks. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for suppressing and monitoring the temperature rise of a double-helix coupling of a large-thrust vibration table moving coil, which specifically includes the following steps:

[0006] Step S1, using two strands of hollow enameled wires to be wound in the same spiral direction into inner and outer layers to form a tightly fitting double-layer dynamic winding structure, wherein the spiral direction angle of the starting point of the inner dynamic winding is the same as the spiral direction angle of the starting point of the outer dynamic winding, and the spiral direction angle of the ending point of the inner dynamic winding is the same as the spiral direction angle of the ending point of the outer dynamic winding;

[0007] Step S2, short-circuiting the starting point of the inner dynamic winding and the starting point of the outer dynamic winding through a wire to form a wiring lead-out terminal 1, short-circuiting the end point of the inner dynamic winding and the end point of the outer dynamic winding through a wire to form a wiring lead-out terminal 2, and electrically connecting the wiring lead-out terminal 1 and the wiring lead-out terminal 2 to the vibration table power amplifier respectively;

[0008] Step S3, providing a connected water outlet at the midpoint of the inner layer dynamic coil winding and the outer layer dynamic coil winding, so as to form a double-layer dynamic coil winding cooling method with water inlet at both ends and water outlet in the middle;

[0009] Step S4, starting from the water inlet of the outer moving coil winding, arrange n temperature sensors on the outer moving coil winding in the spiral winding direction of the outer moving coil winding, respectively denoted as temperature sensor i in the winding order, and the angle coordinate of the temperature sensor i relative to the water inlet of the outer moving coil winding along the coil winding direction is denoted as β i , where: i = 1, 2, L, n; temperature sensor 1 is located at the water inlet of the outer dynamic winding, temperature sensor n is located at the water outlet of the outer dynamic winding, and temperature sensor n+1 is set at the water outlet of the inner dynamic winding;

[0010] Step S5, define the temperature rise change rate evaluation index ξ, the calculation formula of ξ is

[0011]

[0012] Where: Q is the real-time measured flow rate of the cooling water of the moving coil winding, I is the real-time measured current of the moving coil winding, Q max is the maximum cooling water flow of the moving coil winding, I max is the maximum current of the moving coil winding;

[0013] Step S6: Measure the values ​​of each temperature sensor in real time, and record the measured value of the i-th temperature sensor as T i , the measured value of temperature sensor n+1 is T n+1 , define β outer is the angular coordinate of the outer moving coil winding relative to the temperature sensor 1 along the coil winding direction, T outer (β outer ) The temperature distribution function of the outer dynamic winding is based on the measured values ​​T1, T2, L, T of temperature sensor 1 to temperature sensor n. n and their corresponding angular coordinate values ​​β1, β2, L, β n According to the different value ranges of the temperature rise change rate evaluation index ξ, the function reflecting different temperature rise change rates is fitted to obtain the outer dynamic winding temperature distribution function T outer (β outer ).

[0014] Step S7: define βinner is the angle coordinate of the inner moving coil winding relative to the water inlet of the inner moving coil winding along the winding direction of the coil, and the temperature distribution function of the inner moving coil winding T inner (β inner ) can be estimated using the following formula

[0015]

[0016] Step S8: define the upper limit of the maximum temperature difference threshold δ between the inner and outer layers, and compare |T n+1 -T n | and the size of δ, if T n+1 -T n |>δ holds true, indicating that the corresponding layer of the dynamic winding where the sensor with higher temperature among temperature sensor n+1 and temperature sensor n is located is more seriously blocked than the other layer of dynamic winding coil; if |T n+1 -T n |≤δ holds true, indicating that the internal conditions of the inner and outer dynamic winding coils are basically the same.

[0017] Further, in step S6, the outer layer dynamic winding temperature distribution function T outer (β outer ) is estimated as follows:

[0018] If ξ<ξ min ,ξ min The temperature distribution function T of the outer dynamic winding is obtained by fitting and estimating the lower limit threshold of the temperature rise rate. outer (β outer );

[0019] If min ≤ξ≤ξ max ,ξ max The temperature distribution function T of the outer dynamic winding is obtained by fitting and estimating the temperature rise rate upper limit threshold using a quadratic polynomial function. outer (β outer );

[0020] If ξ>ξ max , a polynomial function is used to fit and estimate the temperature distribution function T of the outer dynamic winding. outer (β outer ).

[0021] Furthermore, in step S8, the calculation formula of the upper limit of the maximum temperature difference threshold δ between the inner and outer layers is:

[0022]

[0023] Among them: the value range of δ0 is 25℃~20℃, and the value range of λ is 5℃~10℃.

[0024] Preferably, the hollow enameled wire has a rectangular or circular cross-section.

[0025] Preferably, the number n of the temperature sensors ranges from 4 to 6.

[0026] Preferably, the temperature sensors on the outer moving coil winding are arranged at equal distances.

[0027] Preferably, the temperature sensor is a thermocouple temperature sensor.

[0028] Preferably, the lower limit threshold value ξ of the temperature rise change rate min The value range is 0.7~1.1.

[0029] Preferably, the upper limit threshold value ξ of the temperature rise change rate max The value range is 2 to 2.5.

[0030] The beneficial effects of the present invention are as follows: 1. The present invention adopts a dynamic double-helix coupled parallel power supply method. In this method, the length of the driving coil is twice that of the traditional mode, and the driving current is reduced to half of that in the traditional mode. Although the resistance of the driving coil is twice that of the traditional mode, it can still ensure that the overall heat generation in this case is only half of that in the traditional mode, thereby greatly suppressing the temperature rise of the dynamic coil of the high-thrust vibration table.

[0031] 2. The present invention obtains the temperature distribution along the entire outer moving coil winding by fitting multiple thermocouple temperature sensors at specific positions on the outer moving coil winding. It can comprehensively monitor the temperature conditions at various positions along the outer moving coil winding during the operation of the vibration table, overcoming the problem that the traditional method can only monitor the temperature of individual local points.

[0032] 3. In the process of monitoring the temperature rise of the outer dynamic coil winding, the present invention introduces a temperature rise change rate evaluation index. The index is used to optimize the function form in the temperature rise fitting process, accurately reflecting the temperature rise change rate along the dynamic coil under different cooling water flow rates and driving currents, and the outer dynamic coil temperature monitoring accuracy is higher.

[0033] 4. In the process of monitoring the temperature rise of the inner dynamic winding, the present invention only arranges one temperature sensor at the water outlet of the dynamic winding, utilizes the similarity of the temperature rise laws of the inner and outer dynamic windings, and uses the temperature difference of the water outlet for correction, so that the temperature rise monitoring method of the inner dynamic winding is simple, the number of sensors arranged is small, and the effect is good.

[0034] 5. The present invention overcomes the problem of missed blockage caused by a constant temperature difference threshold value through the difference in water outlet temperature of the inner and outer layers of the dynamic coil winding, combined with a set upper limit of the maximum temperature difference threshold value of the inner and outer layers that monotonically decreases with the evaluation index of the temperature rise change rate. It can make a preliminary diagnosis of whether there is a blockage problem inside the dynamic coil during the temperature rise monitoring process, thereby timely discovering related operational safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the overall scheme diagram of the invented dynamic double-helix coupled temperature rise suppression and monitoring method.

[0036] Figure 2 Schematic diagram of the double-helix coupled dynamic coil structure.

[0037] Figure 3 This is a detailed flow chart of the dynamic double-helix coupling temperature rise suppression and monitoring method. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the embodiments in the accompanying drawings:

[0039] In view of the above problems, the present invention provides a method for suppressing and monitoring the temperature rise of a double-helix coupling of a large-thrust vibration table moving coil, which specifically includes the following steps:

[0040] Step S1, using two strands of hollow enameled wires to be wound into inner and outer layers in the same spiral direction to form a tightly fitting double-layer dynamic winding structure, the spiral direction angle of the starting point of the inner dynamic winding is the same as the spiral direction angle of the starting point of the outer dynamic winding, the spiral direction angle of the ending point of the inner dynamic winding is the same as the spiral direction angle of the ending point of the outer dynamic winding, and the hollow enameled wire has a rectangular or circular cross-section;

[0041] Step S2, short-circuit the starting point of the inner dynamic winding and the starting point of the outer dynamic winding through a wire to form a wiring lead-out terminal 1, short-circuit the end point of the inner dynamic winding and the end point of the outer dynamic winding through a wire to form a wiring lead-out terminal 2, and electrically connect the wiring lead-out terminal 1 and the wiring lead-out terminal 2 to the vibration table power amplifier respectively. In this case, the inner dynamic winding and the outer dynamic winding constitute a two-wire parallel (double-helix coupling) power supply form.

[0042] For an electric vibration table, the magnitude of the exciting force is proportional to the magnetic field strength, the wire length and the current. Generally speaking, the magnetic field strength is constant. In the traditional mode, the electric vibration table adopts a single-wire winding method. In the traditional mode, the length of the moving coil wire is half of the double-wire parallel power supply method of the present invention. In order to ensure the rated exciting force, the driving current in the traditional mode needs to be changed to twice the double-wire parallel power supply method of the present invention. The heat generated by the moving coil is proportional to the square of the driving current and the resistance of the driving coil. The length of the driving coil in the double-wire parallel power supply method of the present invention is twice the length of the driving coil in the traditional mode, so the resistance of the driving coil is also twice that in the traditional mode. However, since the driving current becomes half of that in the traditional mode, the overall heat generated in this case is only half of that in the traditional mode, thereby greatly suppressing the temperature rise of the moving coil of the large-thrust vibration table.

[0043] Step S3, providing a connected water outlet at the midpoint of the inner layer dynamic coil winding and the outer layer dynamic coil winding, so as to form a double-layer dynamic coil winding cooling method with water inlet at both ends and water outlet in the middle;

[0044] Step S4, taking the water inlet of the outer moving coil winding as the starting point, arrange n temperature sensors on the outer moving coil winding in sequence along the spiral winding direction of the outer moving coil winding, and record them as temperature sensors i in the winding order. The temperature sensors on the outer moving coil winding are arranged in an equidistant manner like thermocouple temperature sensors. The angle coordinate of the temperature sensor i relative to the water inlet of the outer moving coil winding along the coil winding direction is marked as β i , where: i = 1, 2, L, n, the value range of n is 4 to 6; temperature sensor 1 is located at the water inlet of the outer dynamic winding, temperature sensor n is located at the water outlet of the outer dynamic winding, and temperature sensor n+1 is set at the water outlet of the inner dynamic winding;

[0045] Step S5, define the temperature rise change rate evaluation index ξ, the calculation formula of ξ is

[0046]

[0047] Where: Q is the real-time measured flow rate of the cooling water of the moving coil winding, I is the real-time measured current of the moving coil winding, Q max is the maximum cooling water flow of the moving coil winding, I max The maximum current of the dynamic winding. This indicator can effectively reflect the cooling effect of the dynamic winding under different driving currents, and thus accurately reflect the temperature rise change rate;

[0048] Step S6: Measure the values ​​of each temperature sensor in real time, and record the measured value of the i-th temperature sensor as T i , the measured value of temperature sensor n+1 is T n+1 , define β outer is the angular coordinate of the outer moving coil winding relative to the temperature sensor 1 along the coil winding direction, Touter (β outer ) The temperature distribution function of the outer dynamic winding is based on the measured values ​​T1, T2, L, T of temperature sensor 1 to temperature sensor n. n and their corresponding angular coordinate values ​​β1, β2, L, β n According to the different value ranges of the temperature rise change rate evaluation index ξ, the function reflecting different temperature rise change rates is fitted to obtain the outer dynamic winding temperature distribution function T outer (β outer ), which can be divided into the following three cases:

[0049] If ξ<ξ min ,ξ min is the lower limit threshold of the temperature rise rate, ξ min The value range of is 0.7~1.1. Since the cooling effect of the dynamic coil is poor at this time, the cooling effect from the coil water inlet to the water outlet is getting worse and worse, and the temperature rise rate is faster as it is closer to the water outlet. Therefore, a cubic polynomial function is used to fit and estimate the outer dynamic coil winding temperature distribution function T outer (β outer );

[0050] If min ≤ξ≤ξ max ,ξ max is the upper threshold of the temperature rise rate, ξ max The value range of is 2~2.5. Since the cooling effect of the dynamic coil is better at this time, although the cooling effect from the coil water inlet to the water outlet will still get worse, this trend has been well improved, and the temperature increase rate near the water outlet has been slowed down. Therefore, the quadratic polynomial function is used to fit and estimate the outer dynamic coil winding temperature distribution function T outer (β outer );

[0051] If ξ>ξ max Since the dynamic coil cooling effect is very good at this time, it can be considered that the temperature rise rate along the dynamic coil is basically the same. The outer dynamic coil winding temperature distribution function T is obtained by fitting and estimating using a first-order polynomial function. outer (β outer ).

[0052] Step S7: define β inner is the angle coordinate of the inner dynamic winding relative to the water inlet of the inner dynamic winding along the winding direction of the coil. Since the inner dynamic winding and the outer dynamic winding have the same structure, cooling method, drive current, and cooling water flow, the temperature distribution law of the inner dynamic winding and the outer dynamic winding is basically the same in theory. Therefore, the temperature distribution function of the inner dynamic winding is T inner (β inner ) can be estimated using the following formula

[0053]

[0054] In this way, slight changes in the inner and outer moving coil windings can be dynamically corrected according to the temperatures at the outlets of the inner and outer moving coil windings.

[0055] Step S8: define the upper limit of the maximum temperature difference threshold δ between the inner and outer layers, and compare |T n+1 -T n | and δ can be used to determine whether there is a significant difference in blockage between the inner and outer dynamic windings. This is because if a dynamic winding is seriously blocked, its outlet temperature will inevitably be much higher than that of the other dynamic winding. Therefore, the specific judgment steps are as follows:

[0056] If |T n+1 -T n |>δ holds true, indicating that the corresponding layer of dynamic winding where the sensor with higher temperature among temperature sensor n+1 and temperature sensor n is located is more seriously blocked than the other layer of dynamic winding coil; if T n+1 -T n |≤δ holds true, indicating that the internal conditions of the inner and outer dynamic winding coils are basically the same. In order to achieve a more accurate judgment of the internal blockage of the coil, the upper limit of the maximum temperature difference threshold δ between the inner and outer layers is calculated as follows:

[0057]

[0058] Among them: the value range of δ0 is 25℃~20℃, and the value range of λ is 5℃~10℃.

[0059] The reason for adopting this method is that the evaluation index ξ with the rate of change of temperature rise reflects the cooling effect of the dynamic winding. The larger the index is, the better the cooling effect is. In this case, even if a coil is blocked to a certain extent, the temperature difference between the inner and outer dynamic windings will be small. At this time, a smaller upper limit of the maximum temperature difference threshold between the inner and outer layers is required to capture the characteristics of the blockage. Therefore, the upper limit of the maximum temperature difference threshold between the inner and outer layers is set as a monotonically decreasing function of the evaluation index ξ with the rate of change of temperature rise, so as to overcome the problem of missed blockage caused by a constant temperature difference threshold.

[0060] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Various changes that can be made within the knowledge scope of technicians in the relevant technical field without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A method for suppressing and monitoring the temperature rise of a double-helix coupling of a large-thrust vibration table, characterized in that: The following steps are involved: S1. Two strands of hollow enameled wires are wound in the same spiral direction into two layers, inner and outer, to form a tightly fitting double-layer dynamic winding structure. The spiral direction angle of the starting point of the inner dynamic winding is the same as the spiral direction angle of the starting point of the outer dynamic winding, and the spiral direction angle of the end point of the inner dynamic winding is the same as the spiral direction angle of the end point of the outer dynamic winding; S2, short-circuiting the starting point of the inner dynamic winding and the starting point of the outer dynamic winding through a wire to form a wiring lead-out terminal 1, short-circuiting the end point of the inner dynamic winding and the end point of the outer dynamic winding through a wire to form a wiring lead-out terminal 2, and electrically connecting the wiring lead-out terminal 1 and the wiring lead-out terminal 2 to the vibration table power amplifier respectively; S3, a connected water outlet is provided at the midpoint of the inner layer dynamic coil winding and the outer layer dynamic coil winding, so as to form a double-layer dynamic coil winding cooling method with water inlet at both ends and water outlet in the middle; S4. Taking the water inlet of the outer moving coil winding as the starting point, n temperature sensors are arranged on the outer moving coil winding in the spiral winding direction of the outer moving coil winding. They are respectively denoted as temperature sensor i in the winding order. The angle coordinate of temperature sensor i relative to the water inlet of the outer moving coil winding along the coil winding direction is denoted as β i , where: i = 1, 2, L, n; temperature sensor 1 is located at the water inlet of the outer dynamic winding, temperature sensor n is located at the water outlet of the outer dynamic winding, and temperature sensor n+1 is set at the water outlet of the inner dynamic winding; S5. Define the temperature rise change rate evaluation index ξ, the calculation formula of ξ is: Where: Q is the real-time measured flow rate of the cooling water of the moving coil winding, I is the real-time measured current of the moving coil winding, Q max is the maximum cooling water flow of the moving coil winding, I max is the maximum current of the moving coil winding; S6. Measure the values ​​of each temperature sensor in real time, and record the measured value of the i-th temperature sensor as T i , the measured value of temperature sensor n+1 is T n+1 , define β outer is the angular coordinate of the outer moving coil winding relative to the temperature sensor 1 along the coil winding direction, T outer (β outer ) The temperature distribution function of the outer dynamic winding is based on the measured values ​​T1, T2, L, T of temperature sensor 1 to temperature sensor n. n and their corresponding angular coordinate values ​​β1, β2, L, β n According to the different value ranges of the temperature rise change rate evaluation index ξ, the function reflecting different temperature rise change rates is fitted to obtain the outer dynamic winding temperature distribution function T outer (β outer ); S7. Define β inner is the angle coordinate of the inner moving coil winding relative to the water inlet of the inner moving coil winding along the winding direction of the coil, and the temperature distribution function of the inner moving coil winding T inner (β inner ) can be estimated using the following formula S8. Define the upper limit of the maximum temperature difference threshold δ between the inner and outer layers, and compare |T n+1 -T n | and the size of δ, if T n+1 -T n |>δ holds true, indicating that the corresponding layer of the dynamic winding where the sensor with higher temperature among temperature sensor n+1 and temperature sensor n is located is more seriously blocked than the other layer of dynamic winding coil; if |T n+1 -T n |≤δ holds true, indicating that the internal conditions of the inner and outer dynamic winding coils are basically the same.

2. According to claim 1, a method for suppressing and monitoring the temperature rise of a double-helix coupling of a dynamic coil of a large-thrust vibration table is characterized in that: In step S6, the outer layer dynamic winding temperature distribution function T outer (β outer ) is estimated as follows: If ξ<ξ min ,ξ min The temperature distribution function T of the outer dynamic winding is obtained by fitting and estimating the lower limit threshold of the temperature rise rate. outer (β outer ); If min ≤ξ≤ξ max ,ξ max The temperature distribution function T of the outer dynamic winding is obtained by fitting and estimating the temperature rise rate upper limit threshold using a quadratic polynomial function. outer (β outer ); If ξ>ξ max , a polynomial function is used to fit and estimate the temperature distribution function T of the outer dynamic winding. outer (β outer ).

3. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: In step S8, the calculation formula of the upper limit of the maximum temperature difference threshold δ between the inner and outer layers is: Among them: the value range of δ0 is 25℃~20℃, and the value range of λ is 5℃~10℃.

4. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The hollow enameled wire has a rectangular or circular cross section.

5. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The value range of the number n of the temperature sensors is 4-6.

6. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The temperature sensors on the outer moving coil winding are arranged in an equidistant manner.

7. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The temperature sensor is a thermocouple temperature sensor.

8. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The lower limit threshold value ξ of the temperature rise change rate min The value range is 0.7~1.

1.

9. The method for suppressing and monitoring the temperature rise of a double-helix coupling of a high-thrust vibration table moving coil according to claim 1 is characterized in that: The upper limit threshold value ξ of the temperature rise change rate max The value range is 2 to 2.5.

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