High-voltage anti-resonance and anti-DC component combined mutual inductor

Abstract

The invention provides a high-voltage anti-resonance and anti-direct-current component combined mutual inductor, and relates to the technical field of combined mutual inductors, the high-voltage anti-resonance and anti-direct-current component combined mutual inductor comprises a combined mutual inductor body, the combined mutual inductor body comprises three or two single-phase combined mutual inductors, and each single-phase combined mutual inductor comprises a voltage mutual inductor module and a current mutual inductor module; a voltage transformer iron core of the voltage transformer module adopts an open magnetic circuit structure, and a magnetic leakage shielding cover is arranged between the voltage transformer module and the current transformer module; and a compensation module is additionally arranged on the voltage transformer module. An iron core of the voltage transformer is of an I-shaped iron core structure, and the iron core is formed by stacking DQ130 silicon steel sheets with the sheet thickness of 0.27 mmm. A current transformer iron core of the current transformer module is provided with a current transformer iron core kerf, and the current transformer iron core of the current transformer module is of an O-shaped cut structure made of ultracrystalline materials. According to the invention, the problem that the closed iron core of the electromagnetic voltage transformer in the existing combined transformer is easy to generate ferromagnetic resonance in a high-voltage power grid is effectively overcome, and the error of the transformer is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of combined mutual inductors, in particular to a high-voltage anti-resonance and anti-DC component combined mutual inductor. Background Art

[0002] High-voltage energy metering uses a combination transformer to convert high voltage and high current into standard voltage and current proportionally, then connects to an energy meter to achieve high-voltage energy metering. A three-phase combination transformer consists of three voltage transformers connected in a Y / Y pattern and three current transformers, accurately measuring the current and voltage of phases A, B, and C simultaneously.

[0003] The combined mutual inductors currently used all have the following defects:

[0004] 1. The electromagnetic voltage transformer has core saturation nonlinear inductance and line capacitive impedance, which can easily excite line voltage resonance, generate resonant overvoltage, and cause the combined transformer to explode and burn; see Figure 1 Voltage transformer excitation curve.

[0005] As the voltage increases, the excitation characteristics of the traditional voltage transformer enter the nonlinear section, and the volt-ampere curve intersects with the system's equivalent capacitance at point P, that is, the system's inductive reactance and capacitive reactance are equal. At this time, the resonance condition is met, and ferromagnetic resonance occurs, which is often called voltage resonance.

[0006] 2. Electromagnetic voltage transformers can also experience low-frequency resonant overvoltages caused by low-frequency components in the line, which can cause explosions and burns in the combined transformer. The low-frequency components in the measured line can cause the core to enter saturation, equalizing the system's equivalent capacitance, thus satisfying the resonant condition and causing resonance.

[0007] 3. At present, due to the increase of local high-frequency, frequency conversion and rectification equipment in the power lines, the DC, low-frequency components and sine half-wave in the lines will cause the electromagnetic current transformer to increase the measurement error under the above conditions. Summary of the Invention

[0008] The present invention provides a high-voltage anti-resonance and anti-DC component combined mutual inductor, which is used to solve at least one of the technical problems raised by the above background technology.

[0009] In order to solve the above technical problems, the present invention discloses a high-voltage anti-resonance and anti-DC component combined transformer, including a combined transformer body, which includes:

[0010] Three or two single-phase combination transformers, the single-phase combination transformer comprising:

[0011] A voltage transformer module and a current transformer module, wherein the voltage transformer core of the voltage transformer module adopts an open magnetic circuit structure, and a leakage magnetic shielding cover is provided between the voltage transformer module and the current transformer module;

[0012] A compensation module is added to the voltage transformer module.

[0013] Preferably, the voltage transformer core adopts an "I"-shaped core structure, the core adopts DQ130, and the silicon steel sheets with a thickness of 0.27mm are stacked. The coils of the voltage transformer primary winding and the voltage transformer secondary winding are wrapped with sealing and buffering materials and cast into shape.

[0014] Preferably, the current transformer core of the current transformer module is provided with a current transformer core slit, the current transformer core of the current transformer module adopts an "O"-shaped cut structure of ultrafine crystal material, the current transformer secondary winding is wound on the current transformer core, and the current transformer primary winding forms an 8-shaped structure.

[0015] Preferably, the compensation module includes: a voltage divider compensation, an N-type voltage transformer core b The first coil is connected to the N terminal of the voltage divider compensation. f1 Winding, voltage divider compensation N f2 The winding is connected in series with the secondary winding of the voltage transformer so that a compensation voltage can be obtained;

[0016] The compensation module further includes: a capacitor connected in parallel to the secondary winding of the voltage transformer.

[0017] Preferably, the voltage transformer module comprises: a voltage transformer body, wherein a voltage transformer core, a voltage transformer primary winding, and a voltage transformer secondary winding are arranged in the voltage transformer body, the voltage transformer primary winding and the voltage transformer secondary winding are both wound on the voltage transformer core, and the voltage transformer body is further equipped with a mounting channel steel;

[0018] The current transformer module includes: a current transformer body, which is arranged on the voltage transformer body; a current transformer primary winding, a current transformer secondary winding, and a current transformer iron core shield are arranged in the current transformer body; the current transformer iron core is arranged in the current transformer iron core shield, and a leakage magnetic shield is arranged outside the current transformer iron core shield; a secondary winding external insulation is arranged outside the current transformer secondary winding; the current transformer primary winding is connected to the primary conductive bar of the combined transformer current and voltage transformer; the combined transformer primary lead is connected to the primary conductive bar of the combined transformer current and voltage transformer;

[0019] The secondary lead of the combined transformer is connected to the secondary winding of the current transformer and the secondary winding of the voltage transformer, the secondary lead of the combined transformer is connected to the secondary lead nut, and the primary winding of the current transformer is connected to the primary winding of the voltage transformer through the primary voltage lead.

[0020] Preferably, it also includes an intelligent monitoring device, which includes:

[0021] Temperature measurement module 1: used to detect the temperature of the key temperature area of the current transformer module;

[0022] a first calculation module configured to determine a current temperature compensation value of the current key temperature zone based on a difference between the temperature of the current key temperature zone of the current transformer module and the temperature of a key temperature zone adjacent to the current key temperature zone, and calculate a current equivalent temperature of each key temperature zone of the current transformer module based on the current temperature compensation value of each key temperature zone of the current transformer module;

[0023] A first determining module is used to determine that the average of the current equivalent temperatures of the first key temperature region in the current class of key temperature regions is the current comprehensive equivalent temperature of the current class of key temperature regions; and the absolute value of the difference between the current equivalent temperature of the first key temperature region in the current class of key temperature regions and the maximum current equivalent temperature of all key temperature regions in the current class of key temperature regions is less than or equal to a preset difference;

[0024] The first warning module is used to issue a warning when the current comprehensive equivalent temperature of the current critical temperature area is greater than or equal to the corresponding first warning temperature.

[0025] Preferably, the intelligent monitoring device further includes:

[0026] A first acquisition module is used to obtain the historical average current and historical average voltage of the primary side of the high-voltage anti-resonance and anti-DC component combination transformer within the latest first historical time period; and to obtain the historical comprehensive equivalent temperature of each key temperature area of the current transformer module within the latest first historical time period; and divide the first historical time period into multiple first historical sub-time periods;

[0027] The second calculation module is used to calculate the heating coefficient of each first historical sub-time period and the equivalent heating coefficient change value of the adjacent first historical sub-time period of each key temperature zone;

[0028] Prediction module: for determining the predicted heating coefficient of each key temperature zone in the future second time period based on the maximum heating coefficient of all first historical sub-time periods of the latest first historical time period and the average heating coefficient of the latest first historical sub-time period, as well as the equivalent heating coefficient change value of adjacent first historical sub-time periods for each key temperature zone;

[0029] The second warning module is used to issue a warning when the ratio of the predicted heating coefficient of the second time period in the future of any type of key temperature area to the corresponding standard heating coefficient is greater than the preset allowable ratio.

[0030] Preferably, the transformer body is mounted on a mounting bracket, and a cooling fan is also mounted on the mounting bracket; a cooling fan adjustment device is also mounted on the mounting bracket, and the cooling fan adjustment device includes:

[0031] Evaluation device, the evaluation device works periodically, and the evaluation device includes:

[0032] Wind speed sensor: installed at the air outlet of the cooling fan to detect the wind speed at its location;

[0033] A first control module is configured to control the cooling fan to operate for a third time period at a first power within the target allowable input power range as the input power, obtain an input power-wind speed variation curve, wherein the abscissa of the input power-wind speed variation curve is the input power and the ordinate is the average detection value of the wind speed sensor during the corresponding third time period, and obtain a wind speed variation coefficient for each first power during the third time period;

[0034] Division module: used to divide the input power-wind speed variation curve into several sub-curve segments, and the difference between the maximum ordinate and the minimum ordinate of each sub-curve segment is less than the preset wind speed difference;

[0035] The cooling fan adjustment device further comprises:

[0036] Temperature sensor: used to detect ambient temperature;

[0037] A second acquisition module is configured to acquire a maximum value of a required heat dissipation of the current combined transformer body during a current first preset time period and a ratio of an actual temperature of all key temperature regions of the current combined transformer body to a corresponding maximum allowable temperature, and determine a current heat dissipation compensation coefficient based on the maximum value;

[0038] A third calculation module is used to determine the current heat dissipation matching degree of each sub-curve segment in the most recently acquired input power-wind speed variation curve based on the required heat dissipation of the current combined transformer body in the current first preset time period, the current heat dissipation compensation coefficient, and the wind speed variation coefficient;

[0039] A second determining module is configured to determine a sub-curve segment whose current heat dissipation matching degree is greater than a first preset value as a target sub-curve segment, and determine a target input power based on the target sub-curve segment;

[0040] The second control module is used to control the cooling fan to operate at the current target input power to perform cooling for a first preset time period.

[0041] 9. A high-voltage anti-resonance and anti-DC component combined transformer according to claim 8, characterized in that: the minimum value of the target allowable input power range is the minimum value of the input power of the cooling fan currently required by the transformer body in history;

[0042] In the second determination module, a target continuous sub-curve segment is determined, wherein there are two continuous target sub-curve segments in the target continuous sub-curve segment, a median of the input power of each target continuous sub-curve segment is determined, and the minimum median is determined as the target input power.

[0043] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. It effectively overcomes the problem that the closed iron core of the electromagnetic voltage transformer in the existing combined transformer is prone to ferromagnetic resonance in the high-voltage power grid, and will not cause long-term overheating and overvoltage due to ferromagnetic resonance, causing the combined transformer to overheat and explode, affecting the safety of line operation.

[0046] 2. Slitting the core of the current transformer improves the magnetic properties of the core, reduces the initial magnetic permeability, and greatly increases the saturation point (9000gs for conventional unslit cores / 18000gs for slit cores). This can eliminate the problem of increased measurement errors caused by low frequency and DC, low frequency components, and half-sine waves on the current transformer.

[0047] 3. The installation of shielding effectively reduces the mutual influence between current and voltage transformers, which causes the transformer error to increase.

[0048] 4. Minimize the mutual inductor error through voltage division and capacitance compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0050] Figure 1 Schematic diagram of the structure of the three-phase combined mutual inductor (two components) of the present invention;

[0051] Figure 2 Schematic diagram of the structure of the three-phase combined mutual inductor (three elements) of the present invention;

[0052] Figure 3 is a circuit diagram of the compensation module of the present invention;

[0053] Figure 4 This is the circuit diagram of the combined mutual inductor;

[0054] Figure 5 is the voltage transformer excitation curve.

[0055] In the figure: 1. Current transformer primary winding; 2. Current transformer body; 3. Current transformer core casing; 4. Leakage magnetic shield; 5. Current transformer core slit; 6. Current transformer core; 7. Current transformer secondary winding; 8. Secondary winding external insulation; 9. Voltage transformer core; 10. Voltage transformer secondary winding; 11. Voltage transformer primary winding; 12. Epoxy resin insulation material; 13. Combination transformer primary lead; 14. Combination transformer secondary lead; 15. Voltage divider compensation; 16. Capacitor; 17. Socket; 18. Phase B terminal; 19. Combination transformer current and voltage transformer primary conductive bar; 20. Shielding bracket; 21. Secondary lead Socket; 22. Mounting channel steel; 23. Channel steel fixing bolts; 24. Primary voltage lead. DETAILED DESCRIPTION

[0056] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0057] In addition, in the present invention, descriptions such as "first" and "second" are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0058] The three-phase high-voltage combined transformer is mainly used to measure the high-voltage power consumption. Figure 4 The measured line is a high-voltage line. The current and voltage transformers are converted into standard values according to the current and voltage ratios and connected to the electric energy meter to realize electric energy measurement. According to the different electricity consumption methods of users, two types of combination transformers are used, one is a three-phase combination transformer (two elements) and the other is a three-element. The two-element is: two single-phase voltage transformers connected in V / V and two current transformers combined together. The three-element is: three single-phase voltage transformers connected in Y / y and three current transformers combined into one. They are put into the mold and vacuum cast by epoxy resin (see for details). Figure 2When the user's three-phase load is relatively balanced, a three-phase two-element combination transformer is used. The electric energy meter collects the A and C phase currents and three-phase voltages and calculates the three-phase electric energy. The B phase current is also calculated and generated. When the three-phase power load is unbalanced, that is, when the B phase current is higher or lower than the A and C phase currents, the calculated B phase current is inaccurate, and three-element metering is selected.

[0059] The current transformers and current transformer arrangement structures of the two (two-element / three-element) structure combination transformers are the same.

[0060] The primary winding terminals of the three-phase voltage A / B / C current transformer are marked P1-P2, and the secondary winding is marked S1-S2. The primary winding of the voltage transformer is marked A / B / C; the secondary is marked a / b / c.

[0061] The present invention provides the following embodiments:

[0062] Example 1: The present invention provides a high voltage anti-resonance and anti-DC component combined mutual inductor, such as Figure 1-Figure 5 As shown, including:

[0063] Three or two single-phase combination transformers, the single-phase combination transformer comprising:

[0064] The voltage transformer module and the current transformer module, the voltage transformer core 9 of the voltage transformer module adopts an open magnetic circuit structure, and a leakage magnetic shielding cover 4 is set between the voltage transformer module and the current transformer module; 4. The installation of electromagnetic shielding reasonably and effectively weakens the influence of leakage magnetic field of current and voltage transformer on transformer error.

[0065] A compensation module is added to the voltage transformer module.

[0066] The voltage transformer core 9 adopts an I-shaped core structure, and the core is made of DQ130 silicon steel sheets with a thickness of 0.27 mm. The coils of the voltage transformer primary winding 11 and the voltage transformer secondary winding 10 are wrapped with sealing and buffering materials and cast into shape.

[0067] The current transformer module's current transformer core 6 is provided with current transformer core slits 5. The core 6 utilizes an "O"-shaped cutout structure made of ultrafine crystal material. The current transformer secondary winding 7 is wound around the core 6, while the current transformer primary winding 1 forms a figure-eight structure. The core slits improve the core's magnetic properties, reduce initial permeability, and significantly increase the saturation point. This eliminates the increased measurement error caused by low-frequency and DC, low-frequency components, and half-sine waves.

[0068] The compensation module includes: a voltage divider compensation 15, an N winding on the voltage transformer core 9 bThe first coil is connected to the voltage divider to compensate for the 15V N f1 Winding, voltage divider compensation 15N f2 The winding is connected in series with the secondary winding 10 of the voltage transformer so that a compensation voltage can be obtained;

[0069] The compensation module further includes a capacitor 16, which is connected in parallel to the voltage transformer secondary winding 10. The voltage transformer error is reduced by using a small voltage divider compensation and capacitor compensation;

[0070] The voltage transformer module includes: a voltage transformer body, in which a voltage transformer core 9, a voltage transformer primary winding 11, and a voltage transformer secondary winding 10 are arranged. The voltage transformer primary winding 11 and the voltage transformer secondary winding 10 are both wound on the voltage transformer core 9. The voltage transformer body is also equipped with a mounting channel steel 22 (mounted by channel steel fixing bolts);

[0071] The current transformer module includes: a current transformer body 2, which is arranged on the voltage transformer body, wherein the current transformer primary winding 1, the current transformer secondary winding 7, and the current transformer core 6 protective shell 3 are arranged in the current transformer body, the current transformer core 6 is arranged in the current transformer core protective shell 3, and a leakage magnetic shielding cover 4 (installed on the shielding bracket 20) is arranged outside the current transformer core protective shell 3; a secondary winding external insulation 8 is arranged outside the current transformer secondary winding 7, the current transformer primary winding 1 is connected to the primary conductive bar 19 of the combined transformer current and voltage transformer, and the primary lead 13 of the combined transformer is connected to the primary conductive bar 19 of the combined transformer current and voltage transformer.

[0072] The combined transformer secondary lead 14 is connected to the current transformer secondary winding 7 and the voltage transformer secondary winding 10 , and the combined transformer secondary lead 14 is connected to the secondary lead nut 21 . The current transformer primary winding 1 is connected to the voltage transformer primary winding 11 through the primary voltage lead 24 .

[0073] The working principle of the above technical solution is:

[0074] The measured current and voltage are from the primary winding 1 (N turns) of the current transformer of the three-phase combination transformer. I1 ) of the combined current transformer and voltage transformer primary conductive bar 19 inputs the primary measured current I1 and the primary measured voltage U1, and the combined current transformer and voltage transformer primary conductive bar 19 is welded to the current transformer primary winding 1; the current I1 is excited by the current transformer core 6, and the ring core (current transformer core 6) is cut; in the current transformer secondary winding 7 (number of turns N I2) induces a secondary current I2, which is connected to the secondary lead female 21 (the secondary lead female is a general term for the secondary leads of current and voltage transformers) through the secondary lead 14 of the combined transformer (the secondary lead of the combined transformer is a general term for the secondary leads of current and voltage transformers); at the same time, the primary measured voltage U1 is input into the primary winding 11 of the voltage transformer (the number of turns N) through the conductive bar 19 via the primary voltage lead 24 of the primary winding 1 of the current transformer U1 ), and at the same time, the voltage is connected to the B phase terminal 18, and the voltage transformer core 9 is excited in the shape of "I" (open magnetic circuit), and the secondary winding 10 (number of turns N U2 ) to induce a secondary voltage U2; connect to the secondary connection female 21 (collectively, the secondary females for current and voltage transformers) via the combined transformer secondary lead 14 (the combined transformer secondary leads are collectively referred to as the secondary leads for the current transformer and voltage transformer). Because the voltage transformer has an open magnetic core, magnetic flux leakage is relatively severe. Therefore, a magnetic flux leakage shield 4 is installed on the upper side of the voltage transformer core, supported by a shield bracket 20 and grounded through the voltage transformer core 9. This effectively shields the voltage transformer core from magnetic flux leakage affecting the current transformer, ensuring current transformer measurement accuracy.

[0075] The measured object is high voltage and large current, and it is installed outdoors, so the current and voltage transformers are installed in the designed mold. After being fixed by the 17 nut, the epoxy resin insulation material 12 is poured as the insulating medium, and an anti-fouling umbrella skirt is designed for outdoor insulation; and the installation channel 22 and the secondary nut 21 for easy wiring are installed.

[0076] like Figure 5 As shown, the excitation curve of the open magnetic circuit voltage transformer of the present invention has no intersection with the system equivalent capacitance curve, and voltage resonance will not occur.

[0077] To ensure the measurement accuracy of the voltage transformer, a voltage divider compensation 15 and a capacitor 16 are installed on the voltage transformer. For details on the compensation circuit, see Figure 3 .

[0078] The voltage divider compensation 15 is wound around the voltage transformer core 9 with Nb turns and the voltage is U b , connect the voltage divider compensation 15, that is, wind Nb on the main transformer core 9 and take N b =1, one turn leads to N for small voltage divider compensation f1 Winding; N f2 The winding is connected in series with the secondary winding of the open magnetic circuit transformer (secondary winding of the voltage transformer 10). In this way, a small compensation voltage can be obtained. If the voltage ratio is K b You get 1 / K b For turn compensation, the contrast value difference compensation amount Δf is:

[0079]

[0080] in

[0081] As long as the core of the small transformer is not saturated, the input impedance of the small transformer is large, and the output impedance is small, the impact on the main transformer is small and can be ignored. A small compensation voltage value will be obtained from the ab terminal (secondary voltage output terminal). This method only compensates for the difference. This compensation can be adjusted after casting to compensate the 15 N f2 Turns compensation makes the error compensation to the best state.

[0082] When the parallel capacitor is 16,

[0083] Δf=sinφωC(Z1+Z2′)×100%

[0084] =0.6ωC(Z1+Z2′)×100% (2)

[0085] Δδ=-cosφωC(Z1+Z2′)×3440

[0086] =-0.8ωC(Z1+Z2′)×3440 (3)

[0087] Where: -Load power factor angle;

[0088] ω - angular frequency;

[0089] C-capacitance value of capacitor 16;

[0090] Z1-primary impedance;

[0091] Z2ˊ-secondary impedance converted to primary;

[0092] It can be seen that for parallel capacitor elements, the contrast difference Δf is positive and the diagonal difference Δδ is negative.

[0093] Compensation capacitors usually use capacitance values that have good stability and can compensate for angular differences to achieve optimal data, and are required to meet the nominal voltage value of the withstand voltage test.

[0094] Instrument transformers (such as voltage transformers and current transformers) are used to proportionally transform voltage or current. Ideally, the electrical quantities (voltage or current) on the primary and secondary sides have a fixed and accurate transformation ratio. However, in practice, due to factors such as the transformer's winding resistance, leakage reactance, and excitation current, the actual transformation ratio of the primary and secondary electrical quantities deviates from the ideal ratio. This deviation manifests as a ratio difference (also called ratio error). To make transformer measurements more accurate, this ratio error needs to be corrected. Ratio difference compensation is an adjustment calculated based on the difference between the transformer's actual measurement and the ideal ratio. By introducing this compensation, the measured value output by the transformer's secondary side is adjusted, thereby reducing the ratio error and bringing the measurement result closer to the true value.

[0095] The beneficial effects of the above technical solution are:

[0096] 1. It effectively overcomes the problem that the closed iron core of the electromagnetic voltage transformer in the existing combined transformer is prone to ferromagnetic resonance in the high-voltage power grid, and will not cause long-term overheating and overvoltage due to ferromagnetic resonance, causing the combined transformer to overheat and explode, affecting the safety of line operation.

[0097] 2. Slitting the core of the current transformer improves the magnetic properties of the core, reduces the initial magnetic permeability, and greatly increases the saturation point (9000gs for conventional unslit cores / 18000gs for slit cores). This can eliminate the problem of increased measurement errors caused by low frequency and DC, low frequency components, and half-sine waves on the current transformer.

[0098] 3. The installation of shielding effectively reduces the mutual influence between current and voltage transformers, which causes the transformer error to increase.

[0099] 4. Minimize the mutual inductor error through voltage division and capacitance compensation.

[0100] Example 2, based on Example 1, further includes an intelligent monitoring device, wherein the intelligent monitoring device includes:

[0101] It also includes an intelligent monitoring device, which includes:

[0102] Temperature measurement module 1: used to detect the temperature of the key temperature area of the current transformer module;

[0103] a first calculation module configured to determine a current temperature compensation value of the current key temperature zone based on a difference between the temperature of the current key temperature zone of the current transformer module and the temperature of a key temperature zone adjacent to the current key temperature zone, and calculate a current equivalent temperature of each key temperature zone of the current transformer module based on the current temperature compensation value of each key temperature zone of the current transformer module;

[0104] A first determining module is used to determine that the average of the current equivalent temperatures of the first key temperature region in the current class of key temperature regions is the current comprehensive equivalent temperature of the current class of key temperature regions; and the absolute value of the difference between the current equivalent temperature of the first key temperature region in the current class of key temperature regions and the maximum current equivalent temperature of all key temperature regions in the current class of key temperature regions is less than or equal to a preset difference;

[0105] The first warning module is used to issue an early warning when the current comprehensive equivalent temperature of the current key temperature zone is greater than or equal to the corresponding first warning temperature (the first warning temperature value is different for different key temperature zones).

[0106] in,

[0107]

[0108] Among them, the above ΔT ij , δ 1ij , δ 3ij , δ 2ij Different values can be taken based on different types of key temperature regions (related to the comprehensive heat transfer coefficient and heat transfer area of the current key temperature region and its adjacent key temperature regions), and can be obtained based on testing before the mass production of the temperature sensor body; M i is the total number of adjacent key temperature regions of the i-th key temperature region; T i is the current equivalent temperature of the i-th critical temperature area; T i1 is the temperature of the temperature measurement module in the i-th key temperature area at the current detection; T ij0 is the temperature currently detected by the temperature measurement module of the jth adjacent key temperature zone of the i-th key temperature zone; δ 1ij ,δ 3ij ,δ 2ij are the first temperature difference correction coefficient, the third temperature difference correction coefficient, and the second temperature difference correction coefficient of the jth adjacent key temperature zone of the i-th key temperature zone to the i-th key temperature zone respectively; ΔT ij is the reference error of temperature compensation between the i-th key temperature region and its j-th adjacent key temperature region (the average value can be greater than 3 and less than 10°C); is the current temperature compensation value of the i-th key temperature area; f(T ij0 -T i1 ) is the current temperature compensation value of the jth adjacent key temperature region of the i-th key temperature region to the i-th key temperature region;

[0109] δ 1ij >δ 3ij >δ 2ij, can be greater than 0 and less than 0.6. In one embodiment, ΔT ij The value can be 4.7℃; δ 1ij , δ 3ij , δ 2ij The values can be 0.189, 0.176, and 0.102 respectively;

[0110] T i is the current equivalent temperature of the i-th critical temperature area of the current transformer module; T i1 T is the current temperature measurement module 1 detection temperature of the i-th key temperature area of the current transformer module; i2 is the average value of the temperatures detected by the current temperature measurement module 1 in the adjacent key temperature areas of the i-th key temperature area of the current transformer module;

[0111] The types of critical temperature areas of the current transformer include: primary winding area, secondary winding area, core area, shell surface area (which can also be subdivided into different types), and terminal area, where each type of critical temperature area is composed of multiple critical temperature areas.

[0112] The beneficial effects of the above technical solution are:

[0113] 1. The temperature measurement module accurately locates the critical temperature areas of the current transformer module and cooperates with the first calculation module to calculate the temperature compensation value based on the temperature difference and derive the equivalent temperature. This makes temperature monitoring no longer limited to a single value, but comprehensively considers the temperature correlation between areas, greatly improving the accuracy and reliability of the monitoring data and providing solid data support for equipment operating status assessment.

[0114] 2. The first determination module and the first warning module work together to issue a timely and accurate warning of possible overheating faults based on the comparison between the current comprehensive equivalent temperature and the preset warning temperature.

[0115] The key temperature areas are classified into different types to determine the current comprehensive equivalent temperature of the current key temperature area. When the current comprehensive equivalent temperature of the current key temperature area is greater than or equal to the corresponding first warning temperature, a warning is issued to achieve reliable classification warning.

[0116] And the average of the current equivalent temperature of the first key temperature area in the current type of key temperature area is determined to be the current comprehensive equivalent temperature of the current type of key temperature area (reducing the impact of considering the lower temperature area), which is convenient for timely warning according to the higher temperature area and targeted selection of appropriate heat dissipation measures and heat dissipation parameters.

[0117] 3. The current temperature compensation value of the current key temperature area is calculated using different temperature difference coefficients for different temperature difference segments, and the calculation is reliable.

[0118] Example 3, based on Example 2, the intelligent monitoring device further includes:

[0119] A first acquisition module is used to obtain the historical average current and historical average voltage of the primary side of the high-voltage anti-resonance and anti-DC component combination transformer within the latest first historical time period; and to obtain the historical comprehensive equivalent temperature of each key temperature area of the current transformer module within the latest first historical time period; and divide the first historical time period into multiple first historical sub-time periods;

[0120] The second calculation module is used to calculate the heating coefficient of each first historical sub-time period and the equivalent heating coefficient change value of the adjacent first historical sub-time period of each key temperature zone;

[0121] Prediction module: for determining the predicted heating coefficient of each key temperature zone in the future second time period based on the maximum heating coefficient of all first historical sub-time periods of the latest first historical time period and the average heating coefficient of the latest first historical sub-time period, as well as the equivalent heating coefficient change value of adjacent first historical sub-time periods for each key temperature zone;

[0122] The second early warning module: is used to issue an early warning when the ratio of the predicted heating coefficient of the second time period in the future of any type of key temperature zone to the corresponding standard heating coefficient (based on the initially used and qualified combined transformer body, the heating coefficient of each type of key temperature zone is determined by testing, and the heating coefficient determined by the test is the standard heating coefficient) is greater than the preset allowable ratio.

[0123] in,

[0124]

[0125] K b is the heating coefficient of the bth first historical sub-period within the latest first historical period of the current key temperature region; c is the average specific heat capacity of the current key temperature region; m is the total weight of the current key temperature region (for example, the core region is divided into several key temperature regions along the length direction); B b1 B is the historical comprehensive equivalent temperature of the current key temperature area at the end of the jth first historical sub-period within the latest first historical period; b2 is the historical comprehensive equivalent temperature of the current key temperature area at the start of the bth first historical sub-period within the latest first historical period; U b 、i b are the historical average voltage and historical average current of the primary side of the high-voltage anti-resonance and anti-DC component combined transformers in the latest first historical time period; f(U b , I b ) is combined with U b , I bThe total heating power of the current transformer obtained (the prior art); t is the duration of each first historical sub-time length;

[0126]

[0127] W is the equivalent heating coefficient change value of the first adjacent historical sub-period of the current critical temperature zone;

[0128] δ1 and δ2 are the first weight and the second weight respectively (both are greater than 0 and less than 1, and can be 0.6 and 0.4 respectively); max represents the maximum value; K (b-1) The heat generation coefficient of the b-1th first historical sub-period within the latest first historical period of the current critical temperature region;

[0129]

[0130] K is the predicted heating coefficient of the second time period in the future for the current key temperature zone; N is the total number of first historical sub-time periods divided by the latest first historical time period; K0 is the maximum heating coefficient of all first historical sub-time periods in the latest first historical time period for the current key temperature zone; K N It is the heating coefficient of the latest (latest time) first historical sub-period in the latest first historical period of the current key temperature zone; C0 is the second period in the future (which can be 30 minutes or 1 hour or other values).

[0131] The beneficial effects of the above technical solution are:

[0132] Comprehensive and Accurate Data: The first acquisition module captures historical average current and voltage on the primary side of high-voltage anti-resonance and anti-DC component combination transformers, as well as historical comprehensive equivalent temperatures in various key temperature zones of the current transformer module, breaking down the historical timeframe. This comprehensive and accurate data collection provides a solid foundation for subsequent analysis and forecasting, enabling in-depth analysis of equipment operating status and temperature patterns.

[0133] Detailed heat analysis: The second calculation module calculates the heat coefficient of each historical sub-time period and the change value of the equivalent heat coefficient of adjacent sub-time periods for each key temperature zone, realizing a detailed analysis of the equipment's heat characteristics, timely detecting abnormal heat fluctuations, and helping to discover potential fault hazards in advance.

[0134] Reliable trend prediction: The prediction module determines the predicted heating coefficient for the second period in the future based on a variety of heating coefficient-related data, effectively predicting the heating trend of key temperature areas of the equipment, providing a reliable basis for the formulation of equipment maintenance and repair plans, and improving the foresight and scientific nature of operation and maintenance.

[0135] Timely and effective early warnings: The second early warning module compares the ratio of the predicted heat coefficient to the standard heat coefficient and the preset allowable ratio, issuing an early warning when it exceeds the range. This provides timely notification of equipment operating anomalies, facilitating a quick response by maintenance personnel, reducing the risk of equipment downtime or damage due to heat failures and ensuring safe and stable equipment operation. It also facilitates rapid identification of critical temperature zones with abnormalities.

[0136] Embodiment 4, based on any one of Embodiments 1-3, the transformer body is mounted on a mounting bracket, and a cooling fan is also mounted on the mounting bracket; a cooling fan adjustment device is also mounted on the mounting bracket, and the cooling fan adjustment device includes:

[0137] Evaluation device, the evaluation device works periodically, and the evaluation device includes:

[0138] Wind speed sensor: installed at the air outlet of the cooling fan to detect the wind speed at its location;

[0139] The first control module: used to control the cooling fan to work for a third time period with the first power in the target allowable input power range (the integer input power in the target allowable input power range is selected as the first power at a preset power interval) as the input power, obtain the input power-wind speed change curve, in which the horizontal axis is the input power and the vertical axis is the average detection value of the wind speed sensor in the corresponding third time period, and obtain the wind speed variation coefficient for the third time period corresponding to each first power (the wind speed variation coefficient corresponding to the current first power is the ratio of the standard deviation of the wind speed sensor detection value in the third time period corresponding to the current first power to the average value of the wind speed sensor detection value in the third time period corresponding to the current first power); the minimum value of the target allowable input power range is the minimum value of the input power of the cooling fan historically required by the current transformer body (or the minimum value of the input power of the cooling fan that may be required by the current transformer body), and the maximum value of the target allowable input power range is the maximum allowable input power of the current cooling fan (or the maximum value of the input power of the cooling fan historically required by the current transformer body);

[0140] Division module: used to divide the input power-wind speed variation curve into several sub-curve segments, and the difference between the maximum ordinate and the minimum ordinate of each sub-curve segment is less than the preset wind speed difference;

[0141] The cooling fan adjustment device further comprises:

[0142] Temperature sensor: used to detect ambient temperature;

[0143] The second acquisition module is used to obtain the maximum value of the required heat dissipation of the current combined transformer body in the current first preset time period and the ratio of the actual temperature of all key temperature areas of the current combined transformer body to the corresponding maximum allowable temperature (the maximum allowable temperature corresponding to different types of key temperature areas is different), and determine the current heat dissipation compensation coefficient based on the maximum value of the ratio of the actual temperature of all key temperature areas of the current combined transformer body to the corresponding maximum allowable temperature;

[0144] A third calculation module is configured to determine a current heat dissipation matching degree (a value that may be greater than 1) of each sub-curve segment in the most recently acquired input power-wind speed variation curve based on the required heat dissipation of the current combined transformer body in the current first preset time period, the current heat dissipation compensation coefficient, and the wind speed variation coefficient;

[0145] A second determination module is configured to determine a sub-curve segment whose current heat dissipation matching degree is greater than a first preset value as a target sub-curve segment, determine a target continuous sub-curve segment, wherein there are two continuous target sub-curve segments in the target continuous sub-curve segment, determine a median value of the input power of each target continuous sub-curve segment, and determine the smallest median value as the target input power;

[0146] The second control module is used to control the cooling fan to operate at the current target input power to perform cooling for a first preset time period.

[0147] In this embodiment, the required heat dissipation of the current combined transformer body during the current first preset time period can be determined based on the current temperature of the combined transformer body and the prior art;

[0148] in,

[0149] G h is the current heat dissipation matching degree of the hth sub-curve segment in the most recently obtained input power-wind speed variation curve; T 10 is the current temperature sensor detection value; ρ is the air density; S is the area of the cooling fan outlet; is the cooling efficiency of the cooling fan (the ratio of the heat exchange amount / cooling amount of the cooling fan to the actual heat dissipation of the combined transformer body; and The corresponding theoretical value can be determined based on testing); E is the required heat dissipation of the current combined transformer body in the current first preset time length; is the average wind speed of the hth sub-curve segment in the most recently obtained input power-wind speed variation curve; c1 is the specific heat capacity of air; T 20 The ambient temperature after the current ambient temperature is allowed to rise; 0.08e 0.13H is the current heat dissipation compensation coefficient; U his the mean value of the maximum wind speed variation coefficient of the first power of the hth sub-curve segment in the most recently obtained input power-wind speed variation curve; H is the maximum value of the ratio of the actual temperature of all key temperature areas of the current combined transformer body to the corresponding maximum allowable temperature; t2 is the first preset time length;

[0150] The beneficial effects of the above technical solution are:

[0151] Precise heat dissipation adaptation: Due to the long-term use of the cooling fan, its input power-wind speed curve may change. The evaluation device operates periodically to determine the latest input power-wind speed curve, accurately grasping the latest correspondence between cooling fan power and wind speed, and determining the wind speed variation coefficient. In combination with the temperature sensor to sense the ambient temperature, and the heat dissipation compensation coefficient determined based on the required heat dissipation of the combined transformer body, the temperature in the critical temperature zone, and the allowable temperature ratio, the cooling fan input power can be precisely adjusted according to the actual heat dissipation requirements of the combined transformer body and the operating status of the cooling fan, achieving dynamic adaptation of heat dissipation to the heating conditions of the combined transformer body, avoiding excessive or insufficient heat dissipation.

[0152] Energy saving and consumption reduction: The partitioning module subdivides the curve and, by calculating the current heat dissipation compatibility of each sub-segment, selects the appropriate target sub-segment and target input power. This allows the cooling fan to operate at a relatively low power while still meeting the cooling requirements, avoiding long-term high power consumption, effectively reducing energy consumption and saving operating costs.

[0153] Strong adaptive adjustment capability: The adjustment device works periodically and can continuously respond in real time to the operating status of the combined transformer body (such as temperature, heat dissipation requirements) and ambient temperature changes, automatically adjusting the working status of the cooling fan without frequent manual intervention. It has strong adaptive adjustment capability, improving the intelligence and convenience of equipment operation management.

[0154] Moreover, the difference between the maximum ordinate and the minimum ordinate of the sub-curve segment is less than the preset wind speed difference, that is, the wind speed state corresponding to each sub-curve segment is relatively close to stable, with small fluctuations, which can ensure the reliability of heat dissipation; and considering the wind speed variation coefficient, it is ensured that the target input power can still meet the heat dissipation requirements after considering the wind speed variation, thereby ensuring the reliability of heat dissipation.

[0155] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A high-voltage anti-resonance and anti-DC component combined transformer, comprising a combined transformer body, characterized in that: The combined transformer body includes: Three or two single-phase combination transformers, the single-phase combination transformer comprising: A voltage transformer module and a current transformer module, wherein the voltage transformer core (9) of the voltage transformer module adopts an open magnetic circuit structure, and a leakage magnetic shielding cover (4) is provided between the voltage transformer module and the current transformer module; A compensation module is added to the voltage transformer module.

2. A high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: The voltage transformer iron core (9) adopts an "I" iron core structure, and the iron core adopts DQ130 silicon steel sheets with a thickness of 0.27 mm, which are stacked, and are covered with the coils of the voltage transformer primary winding (11) and the voltage transformer secondary winding (10), and then wrapped with sealing and buffering materials, and cast into shape.

3. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: The current transformer iron core (6) of the current transformer module is provided with a current transformer iron core slit (5), and the current transformer iron core (6) of the current transformer module adopts an "O"-shaped cut structure of ultra-microcrystalline material. The current transformer secondary winding (7) is wound on the current transformer iron core (6), and the current transformer primary winding (1) is in an 8-shaped structure.

4. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: The compensation module includes: a voltage divider compensation (15), an N-type voltage transformer winding on the voltage transformer core (9), b The first coil is connected to the voltage divider compensation (15) N f1 Winding, voltage divider compensation (15)N f2 The winding is connected in series with the secondary winding (10) of the voltage transformer so that a compensation voltage can be obtained; The compensation module further comprises a capacitor (16), wherein the capacitor (16) is connected in parallel to the secondary winding (10) of the voltage transformer.

5. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: The voltage transformer module comprises: a voltage transformer body, wherein a voltage transformer core (9), a voltage transformer primary winding (11), and a voltage transformer secondary winding (10) are arranged in the voltage transformer body, the voltage transformer primary winding (11) and the voltage transformer secondary winding (10) are both wound on the voltage transformer core (9), and the voltage transformer body is further provided with a mounting channel steel (22); The current transformer module comprises: a current transformer body (2) arranged on the voltage transformer body; a current transformer primary winding (1), a current transformer secondary winding (7), and a current transformer iron core (6) protective shell (3) are arranged in the current transformer body; the current transformer iron core (6) is arranged in the current transformer iron core protective shell (3); a leakage magnetic shielding cover (4) is arranged outside the current transformer iron core protective shell (3); a secondary winding external insulation (8) is arranged outside the current transformer secondary winding (7); the current transformer primary winding (1) is connected to a combined transformer current and voltage transformer primary conductive bar (19); and the combined transformer primary lead (13) is connected to the combined transformer current and voltage transformer primary conductive bar (19); The combined transformer secondary lead (14) is connected to the current transformer secondary winding (7) and the voltage transformer secondary winding (10), the combined transformer secondary lead (14) is connected to the secondary lead female (21), and the current transformer primary winding (1) is connected to the voltage transformer primary winding (11) via a primary voltage lead (24).

6. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: It also includes an intelligent monitoring device, which includes: Temperature measurement module 1: used to detect the temperature of the key temperature area of the current transformer module; a first calculation module configured to determine a current temperature compensation value of the current key temperature zone based on a difference between the temperature of the current key temperature zone of the current transformer module and the temperature of a key temperature zone adjacent to the current key temperature zone, and calculate a current equivalent temperature of each key temperature zone of the current transformer module based on the current temperature compensation value of each key temperature zone of the current transformer module; A first determining module is used to determine that the average of the current equivalent temperatures of the first key temperature region in the current class of key temperature regions is the current comprehensive equivalent temperature of the current class of key temperature regions; and the absolute value of the difference between the current equivalent temperature of the first key temperature region in the current class of key temperature regions and the maximum current equivalent temperature of all key temperature regions in the current class of key temperature regions is less than or equal to a preset difference; The first warning module is used to issue a warning when the current comprehensive equivalent temperature of the current critical temperature area is greater than or equal to the corresponding first warning temperature.

7. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 6, characterized in that: The intelligent monitoring device also includes: A first acquisition module is used to obtain the historical average current and historical average voltage of the primary side of the high-voltage anti-resonance and anti-DC component combination transformer within the latest first historical time period; and to obtain the historical comprehensive equivalent temperature of each key temperature area of the current transformer module within the latest first historical time period; and divide the first historical time period into multiple first historical sub-time periods; The second calculation module is used to calculate the heating coefficient of each first historical sub-time period and the equivalent heating coefficient change value of the adjacent first historical sub-time period of each key temperature zone; Prediction module: for determining the predicted heating coefficient of each key temperature zone in the future second time period based on the maximum heating coefficient of all first historical sub-time periods of the latest first historical time period and the average heating coefficient of the latest first historical sub-time period, as well as the equivalent heating coefficient change value of adjacent first historical sub-time periods for each key temperature zone; The second warning module is used to issue a warning when the ratio of the predicted heating coefficient of the second time period in the future of any type of key temperature area to the corresponding standard heating coefficient is greater than the preset allowable ratio.

8. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 1, characterized in that: The transformer body is mounted on a mounting bracket, and a cooling fan is also mounted on the mounting bracket; a cooling fan adjustment device is also mounted on the mounting bracket, and the cooling fan adjustment device includes: Evaluation device, the evaluation device works periodically, and the evaluation device includes: Wind speed sensor: installed at the air outlet of the cooling fan to detect the wind speed at its location; A first control module is configured to control the cooling fan to operate for a third time period at a first power within the target allowable input power range as the input power, obtain an input power-wind speed variation curve, wherein the abscissa of the input power-wind speed variation curve is the input power and the ordinate is the average detection value of the wind speed sensor during the corresponding third time period, and obtain a wind speed variation coefficient for each first power during the third time period; Division module: used to divide the input power-wind speed variation curve into several sub-curve segments, and the difference between the maximum ordinate and the minimum ordinate of each sub-curve segment is less than the preset wind speed difference; The cooling fan adjustment device further comprises: Temperature sensor: used to detect ambient temperature; A second acquisition module is configured to acquire a maximum value of a required heat dissipation of the current combined transformer body during a current first preset time period and a ratio of an actual temperature of all key temperature regions of the current combined transformer body to a corresponding maximum allowable temperature, and determine a current heat dissipation compensation coefficient based on the maximum value; A third calculation module is used to determine the current heat dissipation matching degree of each sub-curve segment in the most recently acquired input power-wind speed variation curve based on the required heat dissipation of the current combined transformer body in the current first preset time period, the current heat dissipation compensation coefficient, and the wind speed variation coefficient; A second determining module is configured to determine a sub-curve segment whose current heat dissipation matching degree is greater than a first preset value as a target sub-curve segment, and determine a target input power based on the target sub-curve segment; The second control module is configured to control the cooling fan to operate at the current target input power for cooling for a first preset time period.

9. The high-voltage anti-resonance and anti-DC component combined mutual inductor according to claim 8, characterized in that: The minimum value of the target allowable input power range is the minimum value of the input power of the cooling fan required by the current transformer body in history; In the second determination module, a target continuous sub-curve segment is determined, wherein there are two continuous target sub-curve segments in the target continuous sub-curve segment, a median of the input power of each target continuous sub-curve segment is determined, and the minimum median is determined as the target input power.

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