阅读说明：本技术 集成电路电源系统电感元件的磁滞回线确定方法及装置 (Hysteresis loop determining method and device for inductance element of integrated circuit power supply system ) 是由 王芬 于 2021-10-19 设计创作，主要内容包括：本申请提供了一种集成电路电源系统电感元件的磁滞回线确定方法,可包括：向用于集成电路电源系统的电感元件的磁芯中施加磁场；在磁场的作用下,采集磁芯的磁滞回线的多个特征点,其中磁滞回线表示作用于磁芯的磁场强度和磁芯的磁感应强度的变化关系；以及根据多个特征点,确定用于拟合磁滞回线的S曲线的参数,以获得磁滞回线的方程。本申请确定磁滞回线时仅需采集较少数量的特征点,避免了传统方式中确定电感元件的磁滞回线时需要大量采集磁场强度值和磁感应强度值的状况,为确定电感元件的磁滞回线提供了便捷且精确的途径,降低了测量的成本。(The application provides a hysteresis loop determining method of an inductive element of an integrated circuit power supply system, which comprises the following steps: applying a magnetic field into a magnetic core of an inductive element for an integrated circuit power system; under the action of a magnetic field, acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core, wherein the magnetic hysteresis loop represents the change relation between the intensity of the magnetic field acting on the magnetic core and the magnetic induction intensity of the magnetic core; and determining parameters for fitting an S-curve of the hysteresis loop according to the plurality of characteristic points to obtain an equation of the hysteresis loop. The hysteresis loop is determined by the method, only a small number of characteristic points need to be collected, the condition that a large number of magnetic field strength values and magnetic induction strength values need to be collected when the hysteresis loop of the inductance element is determined in a traditional mode is avoided, a convenient and accurate way is provided for determining the hysteresis loop of the inductance element, and the measuring cost is reduced.)

1. A method for determining a hysteresis loop of an inductive element of an integrated circuit power system, comprising:

applying a magnetic field into a magnetic core of an inductive element for an integrated circuit power system;

under the action of the magnetic field, acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core, wherein the magnetic hysteresis loop represents the variation relation between the intensity of the magnetic field acting on the magnetic core and the magnetic induction intensity of the magnetic core; and

and determining parameters for fitting an S curve of the hysteresis loop according to the characteristic points to obtain an equation of the hysteresis loop.

2. The method of claim 1, wherein the characteristic point is a set of pairs of magnetic field strength values of the magnetic field and magnetic induction strength values of the magnetic core, and the characteristic point comprises:

a first characteristic point consisting of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches reverse saturation and a reverse magnetic induction intensity saturation value of the magnetic core;

a second characteristic point consisting of a value of zero and a residual magnetic induction strength value of the magnetic core during magnetization;

a third characteristic point consisting of a coercive force value of the material of the magnetic core in the magnetization process and a numerical value of zero;

a fourth characteristic point consisting of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches the forward saturation and the forward magnetic induction intensity saturation value of the magnetic core;

a fifth characteristic point consisting of a value of zero and a residual magnetic induction strength value of the magnetic core in a demagnetization process; and

and the sixth characteristic point consists of the coercive force value of the material of the magnetic core in the demagnetization process and the numerical value of zero.

3. The method of claim 2, wherein the S-curve is:

，

wherein a, b, c and d each represent a parameter defining the S-curve,eis a natural constant and is a natural constant,xthe variable is represented by a number of variables,yrepresenting the S-curve dependent variablexThe result of the change of (2).

4. The method of claim 3, wherein determining the parameters of the S-curve for fitting the hysteresis loop to obtain the hysteresis loop according to the plurality of characteristic points comprises:

according to the attribute that the output result converges to a fixed value when the variable of the S curve tends to infinity, setting the magnetic field intensity value corresponding to the forward magnetic induction saturation value of the magnetic core and the magnetic field intensity value corresponding to the reverse magnetic induction saturation value of the magnetic core in the characteristic point as positive infinity and negative infinity respectively;

respectively substituting the first characteristic point, the second characteristic point, the third characteristic point and the fourth characteristic point into the S curve to determine an initial value of a parameter of the S curve corresponding to the magnetization process;

determining the accurate value of the parameter of the S curve corresponding to the magnetization process by adopting a Newton iteration method so as to determine the magnetization curve equation of the magnetic core;

respectively substituting the first characteristic point, the fourth characteristic point, the fifth characteristic point and the sixth characteristic point into the S curve to determine an initial value of a parameter of the S curve corresponding to the demagnetization process;

determining the accurate value of the parameter of the S curve corresponding to the demagnetization process by adopting a Newton iteration method so as to determine the demagnetization curve equation of the magnetic core; and

and integrating the magnetization curve equation and the demagnetization curve equation to obtain a magnetic hysteresis loop of the magnetic core.

5. The method of claim 4, wherein the Newton's iteration method comprises:

determining each parameter of the S curve as an iteration variable;

determining a newton iteration formula from the iteration variable, wherein the newton iteration formula represents a formula for deriving a next value of the iteration variable from a previous value of the iteration variable; and

determining an objective function of the iteration variable, and taking a value of the iteration variable corresponding to a module value as an accurate value of a parameter of the S curve in response to the condition that the module value of the objective function is smaller than a preset threshold value; wherein the objective function characterizes a difference between a calculated value at the feature point position obtained using an S-curve with the iteration variable as a parameter and a measured value at the feature point position.

6. An apparatus for determining a hysteresis loop of an inductive element of an integrated circuit power system, comprising:

a magnetic field supply module for applying a magnetic field to a magnetic core of an inductive element for an integrated circuit power supply system;

the acquisition module is used for acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core under the action of the magnetic field, wherein the magnetic hysteresis loop represents the change relation between the magnetic field intensity acting on the magnetic core and the magnetic induction intensity of the magnetic core; and

and the fitting module is used for determining parameters of an S curve for fitting the hysteresis loop according to the plurality of characteristic points so as to obtain an equation of the hysteresis loop.

7. The apparatus for determining hysteresis loop of inductive element of power supply system according to claim 6, wherein said characteristic point is a set of pairs of magnetic field strength value of said magnetic field and magnetic induction strength value of said magnetic core, and said characteristic point comprises:

a first characteristic point consisting of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches reverse saturation and a reverse magnetic induction intensity saturation value of the magnetic core;

a second characteristic point consisting of a value of zero and a residual magnetic induction strength value of the magnetic core during magnetization;

a third characteristic point consisting of a coercive force value of the material of the magnetic core in the magnetization process and a numerical value of zero;

a fourth characteristic point consisting of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches the forward saturation and the forward magnetic induction intensity saturation value of the magnetic core;

a fifth characteristic point consisting of a value of zero and a residual magnetic induction strength value of the magnetic core in a demagnetization process; and

and the sixth characteristic point consists of the coercive force value of the material of the magnetic core in the demagnetization process and the numerical value of zero.

8. The apparatus of claim 7, wherein the S-curve is:

，

wherein a, b, c and d each represent a parameter defining the S-curve,eis a natural constant and is a natural constant,xthe variable is represented by a number of variables,yrepresenting the S-curve dependent variablexThe result of the change of (2).

9. The apparatus of claim 8, wherein the fitting module performs the steps of:

according to the attribute that the output result converges to a fixed value when the variable of the S curve tends to infinity, setting the magnetic field intensity value corresponding to the forward magnetic induction saturation value of the magnetic core and the magnetic field intensity value corresponding to the reverse magnetic induction saturation value of the magnetic core in the characteristic point as positive infinity and negative infinity respectively;

respectively substituting the first characteristic point, the second characteristic point, the third characteristic point and the fourth characteristic point into the S curve to determine an initial value of a parameter of the S curve corresponding to the magnetization process;

determining the accurate value of the parameter of the S curve corresponding to the magnetization process by adopting a Newton iteration method so as to determine the magnetization curve equation of the magnetic core;

respectively substituting the first characteristic point, the fourth characteristic point, the fifth characteristic point and the sixth characteristic point into the S curve to determine an initial value of a parameter of the S curve corresponding to the demagnetization process;

determining the accurate value of the parameter of the S curve corresponding to the demagnetization process by adopting a Newton iteration method so as to determine the demagnetization curve equation of the magnetic core; and

and integrating the magnetization curve equation and the demagnetization curve equation to obtain a magnetic hysteresis loop of the magnetic core.

10. The apparatus of claim 9, wherein the newton's iteration method comprises:

determining each parameter of the S curve as an iteration variable;

determining a newton iteration formula from the iteration variable, wherein the newton iteration formula represents a formula for deriving a next value of the iteration variable from a previous value of the iteration variable; and

determining an objective function of the iteration variable, and taking a value of the iteration variable corresponding to a module value as an accurate value of a parameter of the S curve in response to the condition that the module value of the objective function is smaller than a preset threshold value; wherein the objective function characterizes a difference between a calculated value at the feature point position obtained using an S-curve with the iteration variable as a parameter and a measured value at the feature point position.

Technical Field

The present disclosure relates to the field of integrated circuit technologies, and in particular, to a method and an apparatus for determining a hysteresis loop of an inductive element of an integrated circuit power system.

Background

Power integrity analysis of integrated circuits plays a very important role in integrated circuit design. Research shows that most of energy loss of a system-level integrated circuit power supply system comes from an inductive element for voltage conversion in the power supply system, so that the research on the inductive loss of the system-level integrated circuit power supply system and the reduction of the inductive loss in the energy conversion process as far as possible by an optimization design method have very important significance in the optimization of the power supply system of the system-level integrated circuit.

Due to the nonlinear characteristic of inductance loss, the calculation process is complex, a very accurate solving mode is not completely obtained at present, and especially the influence of direct current bias on loss is not completely clarified. Conventionally, the magnetic hysteresis loop of an inductive element is obtained by a measurement method, i.e. by gradually increasing the external magnetic field strength until magnetic saturation, then gradually decreasing the external magnetic field strength, further increasing the magnetic field strength in the opposite direction until magnetic saturation is reached, recording the magnetic induction strength of the material at different external magnetic field strengths, and finally forming the magnetic hysteresis loop. It can be seen that the current method for obtaining the hysteresis loop of the inductance element is original, and the efficiency is low because multiple measurement results need to be recorded.

Disclosure of Invention

The present application provides a method and apparatus for determining a hysteresis loop of an inductive element of an integrated circuit power system, which is intended to solve or partially solve at least one of the above problems related to the background art and other disadvantages of the related art.

The application provides a hysteresis loop determining method for an inductive element of an integrated circuit power supply system, which comprises the following steps: a magnetic field is applied to a magnetic core of an inductive element for an integrated circuit power system. Under the action of the magnetic field, a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core are acquired, wherein the magnetic hysteresis loop represents the change relation between the intensity of the magnetic field acting on the magnetic core and the magnetic induction intensity of the magnetic core. And determining parameters for fitting an S-curve of the hysteresis loop according to the plurality of characteristic points to obtain an equation of the hysteresis loop.

In some embodiments, the characteristic point is a set of pairs having a correspondence relationship between a magnetic field intensity value of the magnetic field and a magnetic induction intensity value of the magnetic core, wherein the characteristic point may include: and the first characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value of the magnetic core reaches reverse saturation and a reverse magnetic induction intensity saturation value of the magnetic core. And a second characteristic point consisting of a value of zero and a value of residual induction of the core during magnetization. And the third characteristic point consists of the coercive force value of the material of the magnetic core in the magnetization process and the numerical value of zero. And the fourth characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches the forward saturation and the forward magnetic induction intensity saturation value of the magnetic core. And a fifth characteristic point consisting of the value zero and the residual magnetic induction intensity value of the magnetic core in the demagnetization process. And the sixth characteristic point consists of the coercive force value of the material of the magnetic core in the demagnetization process and the numerical value of zero.

In some embodiments, the S-curve is:

，

wherein a, b, c and d each represent a parameter defining an S-curve,eis a natural constant and is a natural constant,xthe variable is represented by a number of variables,yrepresenting the S-curve dependent variablexThe result of the change of (2).

In some embodiments, determining a parameter for fitting an S-curve of the hysteresis loop to obtain the hysteresis loop from the plurality of feature points may include: according to the attribute that the output result converges to a fixed value when the variable of the S curve tends to infinity, the magnetic field intensity value corresponding to the forward magnetic induction saturation value of the magnetic core and the magnetic field intensity value corresponding to the reverse magnetic induction saturation value of the magnetic core in the feature point are set to be positive infinity and negative infinity, respectively. And respectively substituting the first characteristic point, the second characteristic point, the third characteristic point and the fourth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the magnetization process. And determining the accurate value of the parameter of the S curve corresponding to the magnetization process by adopting a Newton iteration method so as to determine the magnetization curve equation of the magnetic core. And respectively substituting the first characteristic point, the fourth characteristic point, the fifth characteristic point and the sixth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the demagnetization process. And determining the accurate value of the parameter of the S curve corresponding to the demagnetization process by adopting a Newton iteration method so as to determine the demagnetization curve equation of the magnetic core. And integrating the magnetization curve equation and the demagnetization curve equation to obtain a magnetic hysteresis loop of the magnetic core.

In some embodiments, the newton iteration method may include: and respectively determining each parameter of the S curve as an iteration variable. From the iteration variable, a newton iteration formula is determined, where the newton iteration formula represents a formula for deriving a next value of the iteration variable from a previous value of the iteration variable. Determining a target function of the iteration variable, and taking a value of the iteration variable corresponding to the module value as an accurate value of a parameter of the S curve in response to the condition that the module value of the target function is smaller than a preset threshold value; wherein the objective function characterizes a difference between a calculated value at a position of the feature point obtained using an S-curve with an iteration variable as a parameter and a measured value at the position of the feature point.

The present application further provides a hysteresis loop determining apparatus for an inductive element of an integrated circuit power system, which may include: the device comprises a magnetic field supply module, an acquisition module and a fitting module. The magnetic field supply module is used for applying a magnetic field to a magnetic core of an inductance element for an integrated circuit power supply system. The acquisition module is used for acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core under the action of a magnetic field, wherein the magnetic hysteresis loop represents the change relation between the magnetic field intensity acting on the magnetic core and the magnetic induction intensity of the magnetic core. The fitting module is used for determining parameters of an S curve for fitting the hysteresis loop according to the plurality of characteristic points so as to obtain an equation of the hysteresis loop.

In some embodiments, the characteristic point is a set of pairs having a correspondence relationship between a magnetic field intensity value of the magnetic field and a magnetic induction intensity value of the magnetic core, wherein the characteristic point may include: and the first characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value of the magnetic core reaches reverse saturation and a reverse magnetic induction intensity saturation value of the magnetic core. And a second characteristic point consisting of a value of zero and a value of residual induction of the core during magnetization. And the third characteristic point consists of the coercive force value of the material of the magnetic core in the magnetization process and the numerical value of zero. And the fourth characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches the forward saturation and the forward magnetic induction intensity saturation value of the magnetic core. And a fifth characteristic point consisting of the value zero and the residual magnetic induction intensity value of the magnetic core in the demagnetization process. And the sixth characteristic point consists of the coercive force value of the material of the magnetic core in the demagnetization process and the numerical value of zero.

In some embodiments, the S-curve is:wherein a, b, c and d each represent a parameter defining an S-curve,eis a natural constant and is a natural constant,xto representThe variables are the variables of the process,yrepresenting the S-curve dependent variablexThe result of the change of (2).

In some embodiments, the performing step of the fitting module may include: according to the attribute that the output result converges to a fixed value when the variable of the S curve tends to infinity, the magnetic field intensity value corresponding to the forward magnetic induction saturation value of the magnetic core and the magnetic field intensity value corresponding to the reverse magnetic induction saturation value of the magnetic core in the feature point are set to be positive infinity and negative infinity, respectively. And respectively substituting the first characteristic point, the second characteristic point, the third characteristic point and the fourth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the magnetization process. And determining the accurate value of the parameter of the S curve corresponding to the magnetization process by adopting a Newton iteration method so as to determine the magnetization curve equation of the magnetic core. And respectively substituting the first characteristic point, the fourth characteristic point, the fifth characteristic point and the sixth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the demagnetization process. And determining the accurate value of the parameter of the S curve corresponding to the demagnetization process by adopting a Newton iteration method so as to determine the demagnetization curve equation of the magnetic core. And integrating the magnetization curve equation and the demagnetization curve equation to obtain a magnetic hysteresis loop of the magnetic core.

In some embodiments, the newton iteration method may include: and respectively determining each parameter of the S curve as an iteration variable. From the iteration variable, a newton iteration formula is determined, where the newton iteration formula represents a formula for deriving a next value of the iteration variable from a previous value of the iteration variable. And determining an objective function of the iteration variable, and taking the value of the iteration variable corresponding to the module value as an accurate value of the parameter of the S curve in response to the condition that the module value of the objective function is smaller than a preset threshold value. The objective function characterizes a difference between a calculated value at a feature point position obtained using an S-curve with an iteration variable as a parameter and a measured value at the feature point position.

According to the technical scheme of the embodiment, at least one of the following advantages can be obtained.

According to the method and the device for determining the hysteresis loop of the inductive element of the integrated circuit power supply system, the initial value of the parameter of the S curve can be determined by collecting a plurality of characteristic points of the inductive element in the integrated circuit power supply and substituting the characteristic points into the S curve, the accurate value of the parameter of the S curve is further determined by adopting a Newton iteration method, and the hysteresis loop of the inductive element is further obtained. The hysteresis loop is determined by the method, only a small number of characteristic points need to be collected, the condition that a large number of magnetic field strength values and magnetic induction strength values need to be collected when the hysteresis loop of the inductance element is determined in a traditional mode is avoided, a convenient and accurate way is provided for determining the hysteresis loop of the inductance element, and the measuring cost is reduced.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings in which:

FIG. 1 is a flow chart of a method for hysteresis loop determination of an inductive element of an integrated circuit power supply system according to an exemplary embodiment of the present application;

FIG. 2 is a schematic diagram of a hysteresis loop in a hysteresis loop determination method for an inductive element of an integrated circuit power system according to an exemplary embodiment of the present application; and

fig. 3 is a schematic configuration diagram of a hysteresis loop determining apparatus of an inductive element of an integrated circuit power supply system according to an exemplary embodiment of the present application.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

In the drawings, the size, dimension, and shape of elements have been slightly adjusted for convenience of explanation. The figures are purely diagrammatic and not drawn to scale. As used herein, the terms "approximately", "about" and the like are used as table-approximating terms and not as table-degree terms, and are intended to account for inherent deviations in measured or calculated values that would be recognized by one of ordinary skill in the art. In addition, in the present application, the order in which the processes of the respective steps are described does not necessarily indicate an order in which the processes occur in actual operation, unless explicitly defined otherwise or can be inferred from the context.

It will be further understood that terms such as "comprising," "including," "having," "including," and/or "containing," when used in this specification, are open-ended and not closed-ended, and specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of" appears after a list of listed features, it modifies that entire list of features rather than just individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including engineering and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

A large part of the energy loss of a system-level integrated circuit power supply system is caused by the inductive loss of an inductive element, so that the research on the inductive loss has great significance in optimizing the power supply integrity of an integrated circuit. The inductance loss of the inductance element is usually obtained through a magnetic hysteresis loop, and the current magnetic hysteresis loop is determined mainly by gradually increasing the intensity of an external magnetic field until the magnetic saturation, then gradually reducing the intensity of the external magnetic field, further reversely increasing the intensity of the magnetic field until the magnetic saturation is reached, recording the magnetic induction intensity of materials under different external magnetic field intensities, and finally forming the magnetic hysteresis loop. In order to solve the problems of low efficiency and poor accuracy of the currently determined hysteresis loop, the application provides a method for recording a small number of characteristic points of the hysteresis loop and then quickly and accurately determining the hysteresis loop of an inductive element of an integrated circuit power supply system through fitting of an S curve based on the small number of characteristic points.

Fig. 1 is a flow chart of a hysteresis loop determination method for an inductive element of an integrated circuit power supply system according to an exemplary embodiment of the present application.

As shown in fig. 1, the present application provides a hysteresis loop determining method for an inductive element of an integrated circuit power system, which may include: step S1, a magnetic field is applied to a magnetic core of an inductive element for an integrated circuit power supply system. And step S2, under the action of the magnetic field, acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core, wherein the magnetic hysteresis loop represents the change relation between the magnetic field intensity acting on the magnetic core and the magnetic induction intensity of the magnetic core. In step S3, parameters of an S-curve for fitting the hysteresis loop are determined according to the plurality of feature points to obtain an equation of the hysteresis loop.

The method is mainly used for determining the hysteresis loop of the inductive element of the integrated circuit power system. In this context, the application first applies a varying magnetic field, which includes a forward magnetic field and a reverse magnetic field, to a magnetic core for the inductive component by means of a magnetic field supply module. That is, the magnetic field strength value of the externally applied magnetic field applied to the magnetic core for the inductance component of the integrated circuit power supply system may be a positive number, a negative number, or may be gradually increased or decreased within a certain range.

Fig. 2 is a schematic diagram of a hysteresis loop in a hysteresis loop determination method for an inductive element of an integrated circuit power supply system according to an exemplary embodiment of the present application.

Specifically, when a magnetic field is applied to a magnetic core for an inductance component used in an integrated circuit power supply system, magnetic induction varying with the intensity of the applied magnetic field is generated inside the magnetic core by the magnetic fieldStrength. The external magnetic field intensity H and the magnetic induction intensity B of the magnetic core of the inductance element have a certain nonlinear relation, and the magnetic induction intensity B increases along with the increase of the magnetic field intensity H and gradually approaches to a fixed value, namely the forward saturation value of the magnetic induction intensity. When the magnetic core reaches magnetic saturation, under the action of an external magnetic field, the magnetic induction intensity B is reduced along with the reduction of the external magnetic field intensity H; further, the magnetic field intensity H is reversely increased, so that the magnetic induction intensity B of the magnetic core is reversely increased and gradually approaches to a fixed value, namely a reverse saturation value of the magnetic induction intensity. Note that, although the saturation magnetic induction values of the cores of the inductance elements made of different materials are different, the saturation magnetic induction values of the cores made of the same material are the same. In other words, the saturation induction value of the magnetic core is determined by the material of the magnetic core. In addition, the coercivity values of the magnetic cores of the same material, i.e. the required external demagnetizing field strength when the magnetic induction of the magnetic core is zero, are also the same(ii) a And when the intensity of the external magnetic field is zero, the residual magnetic induction intensity in the magnetic core made of the same materialThe same applies. Based on the above, a small number of characteristic points that can characterize the hysteresis of the magnetic core can be collected according to the applied condition of the external magnetic field. The characteristic point is a set of pairs having a correspondence relationship between the value of the applied magnetic field and the value of the magnetic induction of the magnetic core. The characteristic points in the present application may include: a first characteristic point consisting of an applied magnetic field intensity value corresponding to the magnetic induction intensity value of the magnetic core when the magnetic induction intensity value reaches reverse saturation, and a reverse magnetic induction intensity saturation value of the magnetic core(ii) a Second characteristic point composed of zero value and residual induction strength value of magnetic core corresponding to magnetization process of magnetic coreWherein, the value zero is the external magnetic field intensity value in the magnetization process, and the residual magnetic induction intensity value is the magnetic induction intensity value of the magnetic core corresponding to the external magnetic field intensity value being zero in the magnetization process; a third characteristic point consisting of the coercive force value of the material of the magnetic core during magnetization, and a numerical value of zeroWherein the coercive force value is an external magnetic field strength value which enables the magnetic induction strength value of the magnetic core to be zero in the magnetization process, and the numerical value zero is the magnetic induction strength value of the magnetic core corresponding to the coercive force value of the magnetic core material in the magnetization process; a fourth characteristic point consisting of the corresponding external magnetic field intensity value when the magnetic induction intensity value of the magnetic core reaches the forward saturation and the forward magnetic induction saturation value of the magnetic core(ii) a A fifth characteristic point consisting of zero value and residual magnetic induction intensity value of the magnetic coreThe numerical value zero is an external magnetic field strength value in the demagnetization process of the magnetic core, and the residual magnetic induction strength value is the magnetic induction strength value of the magnetic core corresponding to the external magnetic field strength value when the external magnetic field strength value is zero in the demagnetization process; and a sixth characteristic point consisting of the coercive force value of the magnetic core material and the numerical value of zero in the demagnetization processAnd the coercive value is an external magnetic field strength value which enables the magnetic induction strength value of the magnetic core to be zero in the demagnetization process, and the numerical value of zero is the magnetic induction strength value of the magnetic core corresponding to the coercive value of the magnetic core material in the demagnetization process.

In some embodiments, the S-curve has the characteristic of being steep in the middle, gentle at both ends, and converging to a fixed value, respectively. As can be seen from fig. 2, the hysteresis loop of the magnetic core includes a magnetization curve and a demagnetization curve, and both the magnetization curve and the demagnetization curve have the same characteristics as the S curve. Specifically, the magnetization curve is a relationship curve between the external magnetic field intensity value and the magnetic induction intensity value generated by the magnetic core in the process that the external magnetic field intensity value along a certain direction is reduced to zero from the maximum in the opposite direction and then is increased to the maximum in the forward direction, and the magnetic core is gradually magnetized; the demagnetization curve is a relation curve of the external magnetic field strength value and the magnetic induction strength value generated by the magnetic core in the process of gradual demagnetization of the magnetic core, wherein the external magnetic field strength value along a certain direction is gradually reduced from the maximum value in the positive direction to zero and then is increased from the negative direction to the maximum. Based on this, this application uses S curve to fit magnetization curve and demagnetization curve respectively, and then can constitute the hysteresis loop of magnetic core.

Specifically, the S-curve is:

，（1）

wherein the content of the first and second substances,a、b、canddeach represents a parameter defining an S-curve,eis a natural constant and is a natural constant,xthe variable is represented by a number of variables,yrepresents the S curve withxThe result of the change of (2).

In some embodiments, the first feature point described above is first set forthThe second characteristic pointThe third characteristic pointAnd fourth characteristic pointSubstituting into equation (1) can obtain:

，（2）

wherein the content of the first and second substances,、、andrespectively, parameters defining the S-curve during magnetization.

The above equation set can not be solved accurately by an analytical method, and a numerical iteration method is required to solve, for this reason, it can be further seen that the first equation and the last equation in the equation set (2) respectively correspond to the magnetic induction intensity of the magnetic core and reach the reverse saturation valueAnd forward saturation valueThe characteristic point of time is based on the characteristic that two ends of the S curve converge to a fixed value, firstly, the magnetic induction intensity of the magnetic core reaches a reverse saturation valueAnd forward saturation valueThe corresponding magnetic field strength is respectively set to be negative infinity and positive infinity, a simplified approximate equation set is obtained, and the parameters of an S curve solved on the basis of the equation set are used as the initial values of the parameters solved by the numerical iteration method. The approximated equation set (2) is simplified as:

。（3）

according to the equation set (3), the initial values of the four parameters of the S curve in the magnetization process can be solved respectively、、Andnamely:

。（4）

further, in order to obtain accurate values of the four parameters of the S-curve during magnetization, the initial values of the four parameters of the S-curve during magnetization are usedAndon the basis of the equation set (4), each parameter is iteratively calculated by adopting a Newton iteration method.

In some embodiments, the newton's iterative formula represents a formula for deriving the next value of an iterative variable from the previous value of the iterative variable, expressed as:

，（5）

in equation (5), P is an iteration vector,iwhich is a natural number, for a magnetization curve,represents the variable ofiThe result of the sub-iteration, F is the objective function,is a jacobian matrix of the objective function.

The target function is the difference value between the value of the S curve at the characteristic point position and the measured value, which is calculated by reversing the parameter of the S curve determined by the iterative method, and the smaller the difference value is, the closer the parameter of the S curve determined by the iterative method is to the true value of the measurement at the characteristic point. The objective function can be expressed as:

，（6）

in the formula (6), the first and second groups,representing sub-objective functions, where i is a natural number, in particular an S-curve with iteration vectors as parameters, in the second placeiThe difference between the value of the position of each feature point and the measured value of the position of the feature point;the value of the S curve at the position of the characteristic point is calculated in reverse according to the parameters of the S curve determined by an iterative method;is a measurement at the location of the feature point;qthe natural number represents the acceleration factor of the constructed objective function in the iteration process;nthe number of sub-targeting functions, or the number of feature points.

The Jacobian matrix of the objective function can be expressed as:

，（7）

in the formula (7), the first and second groups,represents the second of the objective function FSub objective functionTo iterative variable PmA variable quantityThe deviation is calculated and the deviation is calculated,l、mandnare all natural numbers.

In addition, the iterative vector of the magnetization process(may be)Andany of (1). Further, inqIf =1, the iterative vector of the magnetization process is calculatedSubstituting equation (6) gives:

，（8）

initial values of four parameters of an S curve in a magnetization processAndsubstituted into equation (7) can be expressed as:

，（9）

specifically, first, each parameter of the S-curve during magnetization is defined as an iteration variable. Further, the initial values of the parameters of the S-curve in the magnetization process are comparedAndsubstituting into equation (5). It should be noted that wheniWhen the value is not less than 0, the reaction time is not less than 0,is an initial value of an iteration variable, i.e. wheniWhen =0Is composed of、、And. Further, the modulus of the objective function is presetHas a threshold value ofWhen the modulus of the objective functionLess than or equal to a preset threshold valueWhen the temperature of the water is higher than the set temperature,ending the iterative process and calculating the modulus of the objective functionValue of the corresponding iteration variableAs an accurate value of a parameter of the S-curve during magnetization. Furthermore, the accurate value of the parameter of the S curve in the magnetization process is substituted into the S curve, and the magnetization curve equation of the magnetic core hysteresis loop can be obtained. Of course, if the modulus of the objective functionGreater than a predetermined thresholdWhen in use, inFor the initial value of the iteration variable, the iteration operation is continued through the formula (5) untilLess than a predetermined thresholdAnd then ending each parameter iteration process of the S curve in the magnetization process.

In some embodiments, the first characteristic point of the hysteresis loop of the magnetic core is first setFourth characteristic pointThe fifth characteristic pointAnd sixth characteristic pointBy substituting the following equations (1), respectively:

，（10）

wherein the content of the first and second substances,andand parameters for defining an S curve in the demagnetization process respectively.

Similarly, the above equation set cannot be solved accurately by an analytical method, and a numerical iteration method is required to solve the above equation set, for this reason, it can be further seen that the first equation and the last equation in the equation set (10) respectively correspond to the magnetic induction intensity of the magnetic core and reach the reverse saturation valueAnd forward saturation valueThe characteristic point of time is based on the characteristic that two ends of the S curve converge to a fixed value, and the magnetic induction intensity value of the magnetic core is firstly up to a reverse saturation valueAnd forward saturation valueAnd setting the corresponding magnetic field strength values as negative infinity and positive infinity respectively to obtain a simplified approximate equation set, and taking the parameters of an S curve solved based on the equation set as initial values of the parameters solved by the numerical iteration method. Solving the approximate equation set can obtain the initial values of the four parameters of the S curveAndrespectively as follows:

。（11）

further, in order to obtain accurate values of the four parameters of the S-curve during demagnetization, initial values of the four parameters of the S-curve during demagnetization are obtainedAndon the basis, each parameter is subjected to iterative calculation through a formula (5) to obtain accurate values of four parameters of an S curve in the demagnetization process.

Further, an iteration vector of the demagnetization process(may be)Andany of (1). Further, inqWhen =1, the iteration vector of the demagnetization processSubstituting equation (6) gives:

，（12）

further, the target function of the demagnetization process and the initial values of the four parameters of the S curve are used、、Andsubstituting the Jacobian matrix shown in equation (7) can obtain:

，（13）

specifically, first, each parameter of the S-curve in the demagnetization process is defined as an iteration variable. Further, the initial values of the parameters of the S curve in the demagnetization process are comparedAndsubstituting into equation (5). It should be noted that wheniWhen the value is not less than 0, the reaction time is not less than 0,is an initial value of an iteration variable, i.e. wheniWhen =0Is composed of、、And. Further, it is presetHas a threshold value ofWhen is coming into contact withLess than a predetermined thresholdThen the iterative process is ended, andand taking the value of the corresponding iteration variable as an accurate value of the parameter of the S curve in the demagnetization process. Furthermore, the accurate value of the parameter of the S curve in the demagnetization process is substituted into the S curve, and the demagnetization curve equation of the magnetic core hysteresis loop can be obtained. Of course, ifGreater than or equal to a preset threshold valueWhen in use, inFor the initial value of the iteration variable, the iteration operation is continued through the formula (5) untilLess than a predetermined thresholdAnd then the iterative process is ended.

In some embodiments, since the hysteresis loop of the inductance element core is formed by the magnetization curve and the demagnetization curve, the equation of the hysteresis loop of the inductance element core can be obtained by integrating the magnetization curve equation and the demagnetization curve equation.

According to the hysteresis loop determining method of the inductance element of the integrated circuit power supply system, the initial value of the parameter of the S curve can be determined by collecting a plurality of characteristic points of the inductance element in the integrated circuit power supply and substituting the characteristic points into the S curve, the accurate value of the parameter of the S curve is further determined by adopting a Newton iteration method, and the hysteresis loop of the inductance element is further obtained. The hysteresis loop is determined by the method, only a small number of characteristic points need to be collected, the condition that a large number of magnetic field strength values and magnetic induction strength values need to be collected when the hysteresis loop of the inductance element is determined in a traditional mode is avoided, a convenient and accurate way is provided for determining the hysteresis loop of the inductance element, and the measuring cost is reduced.

Fig. 3 is a schematic configuration diagram of a hysteresis loop determining apparatus of an inductive element of an integrated circuit power supply system according to an exemplary embodiment of the present application.

As shown in fig. 3, the present application further provides a hysteresis loop determining apparatus for an inductive element of an integrated circuit power system, which may include: a magnetic field supply module 1, an acquisition module 2 and a fitting module 3. The magnetic field supply module 1 is used for applying a magnetic field to a magnetic core of an inductance element for an integrated circuit power supply system. The acquisition module 2 is used for acquiring a plurality of characteristic points of a magnetic hysteresis loop of the magnetic core under the action of the magnetic field, wherein the magnetic hysteresis loop represents the change relation between the magnetic field intensity acting on the magnetic core and the magnetic induction intensity of the magnetic core. The fitting module 3 is configured to determine a parameter of an S-curve for fitting the hysteresis loop according to the plurality of feature points, so as to obtain an equation of the hysteresis loop.

In some embodiments, the characteristic point is a set of pairs having a correspondence relationship between a magnetic field intensity value of the magnetic field and a magnetic induction intensity value of the magnetic core, wherein the characteristic point may include: and the first characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value of the magnetic core reaches reverse saturation and a reverse magnetic induction intensity saturation value of the magnetic core. And a second characteristic point consisting of a value of zero and a value of residual induction of the core during magnetization. And the third characteristic point consists of the coercive force value of the material of the magnetic core in the magnetization process and the numerical value of zero. And the fourth characteristic point is composed of a magnetic field intensity value corresponding to the magnetic core when the magnetic induction intensity value reaches the forward saturation and the forward magnetic induction intensity saturation value of the magnetic core. And a fifth characteristic point consisting of the value zero and the residual magnetic induction intensity value of the magnetic core in the demagnetization process. And the sixth characteristic point consists of the coercive force value of the material of the magnetic core in the demagnetization process and the numerical value of zero.

In some embodiments, the S-curve is:wherein a, b, c and d each represent a parameter defining an S-curve,eis a natural constant and is a natural constant,xthe variable is represented by a number of variables,yrepresenting the S-curve dependent variablexThe result of the change of (2).

In some embodiments, the performing step of the fitting module 3 may include: according to the attribute that the output result converges to a fixed value when the variable of the S curve tends to infinity, the magnetic field intensity value corresponding to the forward magnetic induction saturation value of the magnetic core and the magnetic field intensity value corresponding to the reverse magnetic induction saturation value of the magnetic core in the feature point are set to be positive infinity and negative infinity, respectively. And respectively substituting the first characteristic point, the second characteristic point, the third characteristic point and the fourth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the magnetization process. And determining the accurate value of the parameter of the S curve corresponding to the magnetization process by adopting a Newton iteration method so as to determine the magnetization curve equation of the magnetic core. And respectively substituting the first characteristic point, the fourth characteristic point, the fifth characteristic point and the sixth characteristic point into the S curve to determine the initial value of the parameter of the S curve corresponding to the demagnetization process. And determining the accurate value of the parameter of the S curve corresponding to the demagnetization process by adopting a Newton iteration method so as to determine the demagnetization curve equation of the magnetic core. And integrating the magnetization curve equation and the demagnetization curve equation to obtain a magnetic hysteresis loop of the magnetic core.

In some embodiments, the newton iteration method may include: and respectively determining each parameter of the S curve as an iteration variable. From the iteration variable, a newton iteration formula is determined, where the newton iteration formula represents a formula for deriving a next value of the iteration variable from a previous value of the iteration variable. And determining an objective function of the iteration variable, and taking the value of the iteration variable corresponding to the module value as an accurate value of the parameter of the S curve in response to the condition that the module value of the objective function is smaller than a preset threshold value. The objective function characterizes a difference between a calculated value at a feature point position obtained using an S-curve with an iteration variable as a parameter and a measured value at the feature point position.

According to the hysteresis loop determining device of the inductive element of the integrated circuit power supply system, a small number of characteristic points of the inductive element in the integrated circuit power supply are collected and substituted into the S curve, so that the initial value of the parameter of the S curve can be determined, the accurate value of the parameter of the S curve is further determined by adopting a Newton iteration method, and the hysteresis loop of the inductive element is further obtained. The hysteresis loop is determined by the method, only a small number of characteristic points need to be collected, the condition that a large number of magnetic field strength values and magnetic induction strength values need to be collected when the hysteresis loop of the inductance element is determined in a traditional mode is avoided, a convenient and accurate way is provided for determining the hysteresis loop of the inductance element, and the measuring cost is reduced.

The objects, technical solutions and advantageous effects of the present invention are further described in detail with reference to the above-described embodiments. It should be understood that the above description is only a specific embodiment of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.