CN111270064B - Control method of coiled iron core annealing process and evaluation method of annealing effect - Google Patents

Control method of coiled iron core annealing process and evaluation method of annealing effect Download PDF

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CN111270064B
CN111270064B CN202010076187.9A CN202010076187A CN111270064B CN 111270064 B CN111270064 B CN 111270064B CN 202010076187 A CN202010076187 A CN 202010076187A CN 111270064 B CN111270064 B CN 111270064B
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annealing
electric heating
heating power
annealing furnace
iron core
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CN111270064A (en
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高仕斌
周利军
张陈擎宇
高旻东
钱鹏
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Changzhou Taipingyang Power Equipment Group Co ltd
Southwest Jiaotong University
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0068—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D11/00—Process control or regulation for heat treatments
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    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets

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Abstract

The invention discloses a control method of a coiled iron core annealing process and an evaluation method of annealing effect. Fitting to obtain an annealing process curve under the conditions of the external dimension parameters of the given wound core and the thermal performance of the material; establishing a heat balance equation of the input electric heating power of the annealing furnace, the surface heat dissipation of the box body and the effective electric heating power in the annealing furnace, monitoring and calculating the heat lost by the box body of the annealing furnace in real time at the stage of constant input power, dynamically adjusting the input electric heating power, and keeping the effective electric heating power consistent with an annealing process curve through the heat balance equation. The invention solves the problems that the internal temperature of the annealing furnace is difficult to directly obtain in the continuous heat preservation stage and the annealing efficiency is difficult to completely reach the expectation. The invention also provides a double evaluation standard combining no-load loss theoretical calculation and experimental test, and improves the reliability of annealing effect evaluation.

Description

Control method of coiled iron core annealing process and evaluation method of annealing effect
Technical Field
The invention belongs to the technical field of production process and heat treatment of electrical equipment, and particularly relates to a control method of a coiled iron core annealing process and an evaluation method of annealing effect.
Background
Energy conservation and consumption reduction are the core components of the national sustainable development strategy. The energy-saving traction transformer for the current rail transit test run adopts a novel rolled iron core structure, the iron core is formed by winding and splicing a plurality of continuously and gradually changed overlong trapezoidal electrical silicon steel strips, and because the corners have no seams and the winding path strictly conforms to the rolling direction of silicon steel sheets in any area, compared with the traditional iron core stacking transformer, the no-load loss of the energy-saving traction transformer can be further reduced. However, the cold-rolled grain-oriented silicon steel sheet used for manufacturing the wound core inevitably has lattice deflection and dislocation in the processes of punching, slicing, winding, carrying and the like, the direction of a crystal axis deviates from the rolling direction of the silicon steel sheet to different degrees, distortion stress of the crystal lattice is generated, the magnetic conductivity of the silicon steel sheet is obviously deteriorated, and no-load loss is increased. Therefore, in the manufacturing process of the large-sized wound core, the heat treatment of high-temperature annealing is an essential process link, and can remove the stress generated in the machining process, so that the original magnetic orientation characteristic of the silicon steel sheet is recovered. The mechanical stress of the large-scale wound core needs to be removed when the temperature inside the annealing furnace reaches a high temperature (800 ℃), meanwhile, the space of the annealing furnace is large, the internal temperature distribution is not uniform, and the heating condition of the wound core at different time intervals is difficult to accurately grasp by the existing technical means. If the annealing effect is not good, the annealing time can be only prolonged or the annealing times can be increased, more electric energy is inevitably consumed, and the production cost is increased. In addition, the evaluation index of the annealing effect of the existing coiled iron core is single, and the accuracy and the reliability of the evaluation index are difficult to guarantee.
Disclosure of Invention
The invention aims to provide a control method of a coiled iron core annealing process and an evaluation method of annealing effect.
A control method of a coiled iron core annealing process comprises the following steps:
step 1: fitting to obtain a curve of the coiled iron core annealing process,
Figure BDA0002378547490000021
wherein Q iseffEffective electric heating power, t annealing time, AmaxThe peak value of the effective electric heating power of the annealing furnace, AconP is the length of the iron yoke of the wound iron core, q is the length of the core column of the wound iron core, and r is the circle of the wound iron core for maintaining the effective electric heating power of the annealing furnaceA corner radius;
step 2: when t is more than or equal to 0 and less than t2Input electric heating power Q of annealing furnaceentEffective electric heating power Q set as coiled iron core annealing process curveeff；
And step 3: will t2≤t＜t3Dividing the time into more than two time periods T; input electric heating power Q of the annealing furnace in the first time period TentEffective electric heating power Q set as coiled iron core annealing process curveeff；
And 4, step 4: calculating the electric heating power Q lost through the surface of the annealing furnace box body in the current time period Tdis，
Figure BDA0002378547490000022
Wherein A iskIs the area of the kth outer surface of the annealing furnace box, TikThe measured temperature of the k-th outer surface of the annealing furnace box, k is 1,2,. and v; n is the number of times the temperature is measured during a time period T, TsThe temperature of the external environment of the annealing furnace, and h is the heat transfer coefficient;
and 5: the input electric heating power Q of the annealing furnace in the next time period TentSet to Q within the current time period TdisEffective electrothermal power Q of next time period TeffAnd returning to the step 4; until t2≤t＜t3Finishing; step 6: when t is3≤t＜t4Input electric heating power Q of annealing furnaceentEffective electric heating power Q set as coiled iron core annealing process curveeff。
A method for evaluating the annealing effect of a wound core comprises the following steps:
step 1: the annealing quality index G is obtained,
Figure BDA0002378547490000031
wherein w is a weight coefficient for evaluation of annealing effect, P0f、P0aBefore and after annealing at constant exciting current I0ConditionMeasured value of the no-load loss, P, obtainedbefAnd PlatBefore and after annealing at constant exciting current I0The theoretical value of the no-load loss obtained under the conditions is as follows:
Figure BDA0002378547490000032
Figure BDA0002378547490000033
in the formula, BampIs the amplitude of the magnetic flux density of the wound core, SjIs the cross-sectional area of the wound core level j, ljIs the winding path length of the wound iron core level j, j is the serial number of the winding level of the silicon steel sheet, m is the total level number of the winding of the silicon steel sheet, f is the excitation frequency, N is the number of turns of the excitation winding, d is the thickness of the silicon steel sheet, sigma is the conductivity of the wound iron core material ξ1、ξ2Hysteresis constants, mu, of the wound core materials before and after annealingbef、μlatEffective magnetic permeability of the coiled iron core material before and after annealing respectively;
step 2: and comparing the annealing quality index G with the no-load loss evaluation coefficient to judge the annealing effect of the wound core.
The invention has the advantages that the heat loss of the annealing furnace box body is monitored and calculated in real time, the input electric heating power is dynamically adjusted, the effective electric heating power is consistent with the annealing process curve through a heat balance equation, and the problems that the internal temperature of the annealing furnace is difficult to directly obtain and the annealing efficiency is difficult to completely reach the expectation in the continuous heat preservation stage are solved. The invention also provides a double evaluation standard combining no-load loss theoretical calculation and experimental test, and improves the reliability of annealing effect evaluation.
Drawings
Fig. 1 is a schematic structural view of a wound core annealing apparatus.
Fig. 2 is a schematic diagram of a fitted curve of the annealing process of the wound core.
Detailed Description
The following describes the process of the present invention in detail with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a coiled iron core annealing device, wherein a high-temperature annealing furnace is a top view, and the external dimension parameters of a rectangular closed space annealing furnace are obtained, the length of the high-temperature annealing furnace is a, the width of the high-temperature annealing furnace is b, and the height of the high-temperature annealing furnace is h. The bell-type annealing furnace is composed of a box body, an electric heating wire, an exhaust valve and the like. For a large-sized wound iron core made of cold-rolled oriented silicon steel sheets, the process requires that the interior of an annealing furnace is kept at 800 ℃ for a long time, and a common temperature measuring device cannot normally work or even is damaged in the high-temperature environment. Therefore, the temperature change of the outer surface of the box body of the annealing furnace is monitored and recorded in real time, and the heat dissipated to the external environment from the box body of the annealing furnace is calculated under the condition, so that the internal environment of the annealing furnace and the heating condition of the coiled iron core are indirectly reflected. The specific scheme is as follows: the PT100 temperature measuring thermal resistors are respectively arranged on the upper surface and four side surfaces of the outer portion of the annealing furnace, the temperature applied to the box body by the heat transfer from the inner portion of the annealing furnace in the annealing process is recorded in real time, the constant-temperature annealing stage is divided into a plurality of time periods, the length of each time period is T, the geometric structure and the material thermal characteristics of the wound core are considered, and the numerical value of T is more suitable for 10-20 minutes. Collecting temperature data with the same number in a time period T, then calculating the average value in the time period, making a difference between the average value and the ambient temperature, and finally obtaining the heat Q lost from the surface of the box body according to a Newton heat transfer formuladisExpression (c):
Figure BDA0002378547490000041
in the formula, AkThe area of the kth outer surface of the annealing furnace box body satisfies A1＝A3＝a×h，A2＝A4＝b×h，A5K is an outer surface position parameter satisfying k ∈ {1,2,3,4,5}, and T is × bikThe measured temperature of the kth outer surface of the annealing furnace box body, n is the number of times of measuring the temperature in a time period T, TsThe temperature of the environment outside the annealing furnace is h is a heat transfer coefficient, and the value of h is 4.9-5.1.
Fig. 2 is a schematic diagram of a fitted curve of the annealing process of the wound core. The annealing scheme is generally described by a curve of the relation between the thermal power and the annealing time, which is called an annealing process curve, and the process of the annealing process is roughly divided into several different stages of 'rapid temperature rise, medium-speed temperature reduction, long-time constant temperature and natural cooling', so that the annealing curve presents the characteristic of a piecewise function. The magnetic properties of electrical silicon steel sheets of different brands are not consistent, and lattice distortion and mechanical stress in the manufacturing processes of punching, cutting, winding, carrying and the like are also different, so that the actual annealing curve needs to be customized according to different objects.
When the annealing of the wound core is carried out,
step 1: the curve of the coiled iron core annealing process is obtained by fitting, namely the effective electric heating power QeffThe dynamic relationship with the annealing time t includes a rapid increase (0 to t)1Time step), medium speed descent (t)1～t2Time phase), remains constant (t)2～t3Time phase) and constant rate of descent (t)3～t4Time phase), and the like, specifically described as a piecewise function:
Figure BDA0002378547490000051
wherein A ismaxThe peak value of the effective electric heating power of the annealing furnace, AconP is the length of the iron yoke of the wound iron core, q is the length of the core column of the wound iron core, and r is the radius of the fillet of the wound iron core;
step 2: and starting the annealing furnace and entering an annealing process link. 0 to t1Time period and t1～t2Time step, input electric heating power QentDynamic adjustment is implemented through a power supply variable resistance control module, so that the dynamic adjustment strictly corresponds to a wound core annealing process curve;
and step 3: t is t2～t3The time phase is divided into a plurality of time periods T. Input electric heating power Q of annealing furnace in first time period TentEffective electrothermal power Q set to be corresponding to time period T of the iron core rolling annealing process curveeff. Time periodAfter T, calculating the electric heating power Q lost through the surface of the annealing furnace box body in the current time period Tdis，
Figure BDA0002378547490000061
Wherein the annealing furnace has v different outer surfaces, the specific value is related to the shape of the annealing object,
in the case given by the present invention, v takes the value 5;
and 4, step 4: if t2～t3Stopping collecting the temperature of the outer surface of the box body of the annealing furnace after the time period is finished; otherwise, the next time period T of the annealing furnace inputs the electric heating power QentFor Q in the current time period TdisEffective electric heating power Q corresponding to the starting moment of the next time period TeffAnd returning to the step 3 to recalculate the electric heating power lost on the surface of the box body of the annealing furnace in the next time period.
And 5: t is t3～t4Time-phased input electric heating power QentKeeping the adjustment of the temperature of the iron core to be consistent with that in the step 2, closing the power supply module of the annealing furnace after the time period is finished, keeping the temperature of the iron core to be 4-6 hours, and naturally cooling the iron core to room temperature to finish annealing.
The cold-rolled oriented silicon steel sheet adopted for manufacturing the large-scale wound iron core has internal magnetic domains and crystal lattices rearranged through a rolling process, and has more excellent magnetic conductivity, but the electrical steel sheet is manufactured into a complete wound iron core and must be subjected to the process of punching, shearing, slicing, winding, carrying and the like, so that the crystal lattices of the silicon steel sheet inevitably deflect and are dislocated, the distortion stress of the crystal lattices is generated, and the magnetic conductivity of the silicon steel sheet is obviously deteriorated. The high temperature annealing heat treatment process is to eliminate the increase of no-load loss caused by the mechanical stress. Therefore, it is reasonable to use the numerical value of the no-load loss before and after annealing of the wound core as an evaluation index of the annealing effect, and in order to further ensure the reliability of the evaluation, the evaluation is performed by using a double index of the theoretical value and the measured value of the no-load loss of the wound core before and after annealing.
When the transformer operates in no-load operation, because the no-load current required by excitation is very small, the loss generated in the winding can be ignored, so the no-load loss mainly refers to the loss of an iron core, and the loss can be divided into hysteresis loss and eddy current loss. When the transformer core is subjected to alternating excitation, the arrangement of magnetic domains in the ferromagnetic material also shows periodic alternation, so that hysteresis is generated, and the power loss of the part is called hysteresis loss. The hysteresis loss of the iron core is closely related to the magnetization curve of the electrical steel sheet, but the loss mechanism is complex, and modeling analysis is very complicated, so the engineering usually adopts the following approximate calculation:
Figure BDA0002378547490000071
in the formula, PhFor hysteresis loss of wound core, f is the excitation frequency, BampIt is the amplitude of the magnetic flux density of the wound core, ξ is the hysteresis constant of the material of the wound core, V is the volume of the wound core, since the wound core exhibits the characteristic of width grading and the winding path of each grade is different, and after considering the special geometrical structure, a clear calculation formula is obtained:
Figure BDA0002378547490000072
wherein S isiIs the cross-sectional area of the wound core at different levels,/iThe winding path lengths of different levels of the wound iron core are shown, j is the serial number of the winding level of the silicon steel sheet, and m is the total level number of the winding of the silicon steel sheet.
When magnetic flux flows along the direction of the winding path, electromotive force is generated on the cross section of the wound core perpendicular to the magnetic flux according to the faraday's law of electromagnetic induction, and since the silicon steel sheet itself is a good electrical conductor, a circular current, i.e., an eddy current, occurs. According to lenz's law, the magnetic field generated by the eddy current will hinder the change of the original magnetic field, which is called the demagnetization effect of the eddy current, and the consumed energy is called the eddy current loss. Through more strict Maxwell equation analysis, the universal average eddy current loss P in unit volume can be obtainedceThe calculation formula (c) is as follows:
Figure BDA0002378547490000073
wherein d is the thickness of the silicon steel sheet, μ is the effective permeability of the material of the wound core, σ is the conductivity of the material of the wound core, and HmThe average value of the magnetic field intensity amplitude of the wound core is obtained. However, since the distribution of the magnetic field strength and the magnetic flux density of the wound core is not uniform in different levels, the magnetic field strength or the magnetic flux density of each level should be used as a boundary condition of the eddy current loss equation of each level, and finally the loss is summed to obtain the eddy current loss of the entire wound core. Therefore, the calculation formula of the average eddy current loss per unit volume of the single-stage silicon steel sheet is improved as follows:
Figure BDA0002378547490000081
in the formula, PeiTo take account of the average eddy current losses per unit volume after an uneven distribution of the magnetic flux at different levels, HiThe amplitude of the boundary magnetic field intensity of different levels is described, and the ampere loop law F-NI is adopted0＝Hi·liEquivalent substitution is made for it, wherein: f is the magnetomotive force of different winding levels, N is the number of turns of the exciting winding, I0Is the excitation current.
Therefore, the wound core eddy current loss expression considering the actual geometry and process characteristics is as follows:
Figure BDA0002378547490000082
based on the above, defining the annealing quality index G to judge the annealing effect of the large-sized wound core:
Figure BDA0002378547490000083
w is a weight coefficient of annealing effect evaluation, the value is 0.6-0.65, and P0f、P0aBefore and after annealing at constant exciting current I0Measured value of no-load loss, P, obtained under the conditionsbefAnd PlatBefore and after annealing at constant exciting current I0The calculation method of the no-load loss theoretical value obtained under the condition is as follows:
Figure BDA0002378547490000084
Figure BDA0002378547490000085
in the formula, ξ1、ξ2Hysteresis constants, mu, of the wound core materials before and after annealingbef、μlatThe effective magnetic permeability of the material of the rolled iron core before and after annealing respectively, wherein ξ1、ξ2、μbef、μlatThe value of (A) is determined by a wound core magnetization curve test;
if G is larger than or equal to G, judging that the annealing effect is better, otherwise, carrying out secondary annealing, wherein: the value of the no-load loss evaluation coefficient is 0.05-0.1.

Claims (1)

1. A control method for an annealing process of a wound core is characterized by comprising the following steps:
step 1: fitting to obtain a curve of the coiled iron core annealing process,
Figure FDA0002611979670000011
wherein Q iseffEffective electric heating power, t annealing time, AmaxThe peak value of the effective electric heating power of the annealing furnace, AconP is the length of the iron yoke of the wound iron core, q is the length of the core column of the wound iron core, and r is the radius of the fillet of the wound iron core;
step 2: when t is more than or equal to 0 and less than t2Input electric heating power Q of annealing furnaceentEffective electric heating power Q set as coiled iron core annealing process curveeff；
And step 3: will t2≤t＜t3Dividing the time into more than two time periods T; input electric heating power Q of the annealing furnace in the first time period TentEffective electric heating power Q set as coiled iron core annealing process curveeff；
And 4, step 4: calculating the electric heating power Q lost through the surface of the annealing furnace box body in the current time period Tdis，
Figure FDA0002611979670000012
Wherein A iskIs the area of the kth outer surface of the annealing furnace box, TikThe measured temperature of the k-th outer surface of the annealing furnace box, k is 1,2,. and v; n is the number of times the temperature is measured during a time period T, TsThe temperature of the external environment of the annealing furnace, and h is the heat transfer coefficient;
and 5: the input electric heating power Q of the annealing furnace in the next time period TentSet to Q within the current time period TdisEffective electrothermal power Q of next time period TeffAnd returning to the step 4; until t2≤t＜t3Finishing;
step 6: when t is3≤t＜t4Input electric heating power Q of annealing furnaceentEffective electric heating power Q set as coiled iron core annealing process curveeff。
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CN112016204B (en) * 2020-08-27 2022-04-26 西南交通大学 Eddy current loss analysis method considering nonlinear magnetic property of autotransformer wound core material
CN112016205B (en) * 2020-08-28 2021-08-13 西南交通大学 Method for analyzing annealing quality of autotransformer wound core
CN114242425B (en) * 2021-10-22 2023-06-02 西南交通大学 Hysteresis loss solving method for traction transformer considering iron core magnetic circuit grading

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62219507A (en) * 1986-03-19 1987-09-26 Matsushita Electric Ind Co Ltd Control method of annealing temperature of iron core for electric apparatus
CN102586566A (en) * 2012-03-15 2012-07-18 青岛海立美达电机有限公司 Heat treatment process for iron core of motor
CN108693418A (en) * 2018-04-02 2018-10-23 西南交通大学 A kind of assessment method of large size rewinding material annealing effect

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62219507A (en) * 1986-03-19 1987-09-26 Matsushita Electric Ind Co Ltd Control method of annealing temperature of iron core for electric apparatus
CN102586566A (en) * 2012-03-15 2012-07-18 青岛海立美达电机有限公司 Heat treatment process for iron core of motor
CN108693418A (en) * 2018-04-02 2018-10-23 西南交通大学 A kind of assessment method of large size rewinding material annealing effect

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