CN114141471A - Demagnetization system, method, device and medium - Google Patents
Demagnetization system, method, device and medium Download PDFInfo
- Publication number
- CN114141471A CN114141471A CN202111516277.6A CN202111516277A CN114141471A CN 114141471 A CN114141471 A CN 114141471A CN 202111516277 A CN202111516277 A CN 202111516277A CN 114141471 A CN114141471 A CN 114141471A
- Authority
- CN
- China
- Prior art keywords
- transformer
- full
- bridge circuit
- demagnetization
- current value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005347 demagnetization Effects 0.000 title claims abstract description 130
- 238000000034 method Methods 0.000 title claims abstract description 63
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 49
- 229920006395 saturated elastomer Polymers 0.000 claims abstract description 48
- 230000002441 reversible effect Effects 0.000 claims abstract description 38
- 238000004590 computer program Methods 0.000 claims description 12
- 230000004907 flux Effects 0.000 description 61
- 230000005415 magnetization Effects 0.000 description 12
- 230000008569 process Effects 0.000 description 9
- 238000004364 calculation method Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000012545 processing Methods 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 230000002427 irreversible effect Effects 0.000 description 3
- 230000005381 magnetic domain Effects 0.000 description 3
- 230000005389 magnetism Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000013473 artificial intelligence Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000010801 machine learning Methods 0.000 description 1
- 230000005055 memory storage Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F13/00—Apparatus or processes for magnetising or demagnetising
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application discloses a demagnetization system, a demagnetization method, a demagnetization device and a demagnetization medium, which comprise the following steps: the device comprises a controller, a full-bridge circuit and a current acquisition module. The first end of full-bridge circuit is connected with the first end of transformer, the second end of full-bridge circuit is connected with the second end of transformer, and the common port is connected with the current acquisition module, the current acquisition module is connected with the controller, be used for gathering the current secondary survey current value of transformer, the controller is connected with the control end of full-bridge circuit, be used for when the iron core of transformer is saturated, the output voltage of control full-bridge circuit is changed into reverse phase voltage by the forward voltage, and when current secondary side current value reached and predetermine the current value, control full-bridge circuit stopped output voltage. Therefore, according to the technical scheme provided by the invention, the controller is used for controlling the forward voltage output by the full-bridge circuit to be changed into the reverse voltage, and when the current secondary side current of the transformer reaches the preset current value, the controller is used for controlling the output voltage to be stopped so as to realize rapid demagnetization, and the demagnetization efficiency of the transformer is improved.
Description
Technical Field
The present application relates to the field of demagnetization technologies, and in particular, to a demagnetization system, method, apparatus, and medium.
Background
When a main transformer of a newly-built transformer substation is put into operation or put into operation again after the transformer is overhauled, a large excitation surge current can appear in the no-load switching-on transformer, and the safety and stable operation of a power grid can be directly influenced by the overhigh excitation surge current. When the circuit breaker is closed again, the residual magnetic flux may cause the iron core of the transformer to be saturated, which causes the magnetizing inrush current to be too high, and thus, the magnetizing inrush current has an important influence on the ac/dc power grid. Therefore, removing residual flux in the core is critical to the proper operation of the grid.
Because the time interval between each reclosing action of the circuit breaker is short, only a method of high-speed operation can be used for relieving residual magnetic flux so as to prevent the magnetizing inrush current from being too high due to the saturation of a transformer core. At present, a direct-current demagnetization method, an alternating-current demagnetization method and a composite demagnetization method are generally used for eliminating residual magnetic flux of an iron core, the direct-current demagnetization method is used for eliminating magnetizing current by applying coercive force to reduce magnetic flux density B to zero, and the direct-current demagnetization method needs to accurately obtain magnetic flux density, magnetic flux strength and a magnetic hysteresis loop of the iron core, and is complex in operation and high in cost. The alternating current demagnetization method is characterized in that a transformer is placed in a series of alternating magnetic fields with slowly-reduced amplitudes, so that the residual magnetic flux of an iron core of the transformer is slowly reduced to zero, the process is time-consuming by adopting a cyclic demagnetization method, and especially in a high-voltage system, a large-scale power transformer needs a lot of time for the demagnetization process due to the slow attenuation of inductive eddy currents and the difficulty in changing the polarity of magnetic domains. The compound demagnetization method is characterized in that the original residual magnetic flux of the magnet is faded to be low enough through a direct current reverse magnetic field with enough strength, then the residual magnetic flux is completely eliminated through an alternating magnetic field generated by a power frequency low-voltage current, the process is complicated by adopting the compound demagnetization method, and the demagnetization speed is low.
Therefore, how to accurately and quickly realize demagnetization of the transformer is a problem to be solved urgently by a person skilled in the art.
Disclosure of Invention
The application aims to provide a demagnetization system, a demagnetization method, a demagnetization device and a demagnetization medium.
In order to solve the above technical problem, the present application provides a demagnetization system, including: the device comprises a controller, a full-bridge circuit and a current acquisition module;
the first end and the second end of the full-bridge circuit are respectively connected with the first end and the second end of the transformer, and the common end of the second end of the full-bridge circuit and the second end of the transformer is connected with the current acquisition module;
the current acquisition module is connected with the controller and used for acquiring the current secondary measured current value of the transformer;
the controller is connected with the control end of the full-bridge circuit and used for controlling the output voltage of the full-bridge circuit to be changed from forward voltage to reverse voltage when the iron core of the transformer is saturated, and controlling the full-bridge circuit to stop outputting the voltage when the current secondary side current value reaches a preset current value.
Preferably, the demagnetization system further comprises a switching device;
one end of the switching device is connected with the common end of the first end of the full-bridge circuit and the first end of the transformer, and the other end of the switching device is connected with the common end of the second end of the full-bridge circuit and the second end of the transformer.
Preferably, the full-bridge circuit comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a voltage source;
the control end of the first switching tube, the control end of the second switching tube, the control end of the third switching tube and the control end of the fourth switching tube are connected with the controller;
the first end of first switch tube with the second end of second switch tube is connected, and the common port conduct the first end of full-bridge circuit, the second end of first switch tube with the first end of third switch tube is connected, and the common port with the one end of voltage source is connected, the first end of second switch tube with the second end of fourth switch tube is connected, and the common port with the other end of voltage source is connected, the second end of third switch tube with the first end of fourth switch tube is connected, and the common port conduct the second end of full-bridge circuit.
Preferably, the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are all triodes with body diodes.
In order to solve the above technical problem, the present application further provides a demagnetization method, applied to the demagnetization system, including:
acquiring the current secondary side current value of the transformer;
judging whether an iron core of the transformer is saturated or not, and if so, controlling the output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage;
and determining whether the current secondary side current value reaches a preset current value, and if so, controlling the full-bridge circuit to stop outputting the voltage.
Preferably, the preset current value is obtained by calculation according to a J-A hysteresis model.
Preferably, the determining whether the core of the transformer is saturated includes:
calculating a saturated secondary measured current value when an iron core of the transformer is saturated;
and judging whether the current secondary side current value is equal to the saturated secondary measured current value or not, and if so, determining that the iron core of the transformer is saturated.
In order to solve the above technical problem, the present application further provides a demagnetization device, including:
the acquisition module is used for acquiring the current secondary side current value of the transformer;
the judging module is used for judging whether the iron core of the transformer is saturated or not, and if the iron core of the transformer is saturated, the first control module is called;
the first control module is used for controlling the output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage;
the determining module is used for determining whether the current secondary side current value reaches a preset current value or not, and if so, calling the second control module;
and the second control module is used for controlling the full-bridge circuit to stop outputting the voltage.
In order to solve the above technical problem, the present application further provides a demagnetization device, including a memory for storing a computer program;
a processor for implementing the steps of the demagnetization method when executing the computer program.
In order to solve the above technical problem, the present application further provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the demagnetization method.
The demagnetization system provided by the invention comprises: the device comprises a controller, a full-bridge circuit and a current acquisition module. The first end of full-bridge circuit is connected with the first end of transformer, the second end of full-bridge circuit is connected with the second end of transformer, and the common terminal is connected with the current acquisition module, the current acquisition module still is connected with the controller for gather the current secondary survey current value of transformer, in addition, the controller is connected with the control end of full-bridge circuit, be used for when the iron core of transformer is saturated, the output voltage of control full-bridge circuit is changed into reverse phase voltage by the forward voltage, and when current secondary side current value reached and predetermines the current value, control full-bridge circuit stopped output voltage. Therefore, according to the technical scheme provided by the invention, when the iron core of the transformer is saturated, the output voltage of the full-bridge circuit is controlled by the controller to be changed from the forward voltage to the reverse voltage so as to reduce the magnetic flux intensity and the magnetic flux density of the transformer, and when the current secondary side current of the transformer reaches the preset current value, the full-bridge circuit is controlled to stop outputting the voltage so as to realize demagnetization of the transformer, so that the demagnetization of the transformer is quickly and accurately realized by changing the voltage applied to the transformer, and the demagnetization efficiency of the transformer is improved.
In addition, the invention also provides a demagnetization method, a demagnetization device and a medium, which correspond to the demagnetization system and have the same effects.
Drawings
In order to more clearly illustrate the embodiments of the present application, the drawings needed for the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained by those skilled in the art without inventive effort.
Fig. 1 is a structural diagram of a demagnetization system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a B-H hysteresis curve based on a J-A hysteresis model according to an embodiment of the present invention;
fig. 3 is a flowchart of a demagnetization method according to an embodiment of the present invention;
fig. 4 is a structural diagram of a demagnetizing device provided in an embodiment of the present invention;
fig. 5 is a structural diagram of a demagnetizing device according to another embodiment of the present invention;
the reference numbers are as follows: the controller is 1, the full-bridge circuit is 2, the current acquisition module is 3, and the transformer is 4.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the present application.
The core of the application is to provide a demagnetization system, a demagnetization method, a demagnetization device and a demagnetization medium, when an iron core of a transformer is saturated, the output voltage of a full-bridge circuit is controlled by a controller to be changed from a forward voltage to a reverse voltage, and when the current secondary side current of the transformer reaches a preset current value, the controller controls the full-bridge circuit to stop outputting the reverse voltage, so that the magnetic flux density and the magnetic flux intensity are gradually changed to zero to realize demagnetization of the transformer.
In order that those skilled in the art will better understand the disclosure, the following detailed description will be given with reference to the accompanying drawings.
When the breaker is closed again, the residual magnetic flux can cause the iron core of the transformer to be saturated, so that the excitation surge is too high, and the important influence is generated on the AC/DC power grid. Therefore, removing residual flux in the core is critical to the proper operation of the grid.
At present, a direct current demagnetization method, an alternating current demagnetization method and a composite demagnetization method are generally used for eliminating residual magnetic flux of an iron core, the main principle of the direct current demagnetization is to apply a magnetic field opposite to an original magnetic field to a magnet to achieve demagnetization of a transformer, although the principle is simple, the direct current demagnetization needs to accurately obtain the magnetic flux density, the magnetic flux strength and a hysteresis loop of the iron core, in addition, the iron core needs to be switched back and forth for several times to achieve complete demagnetization, and the operation is complex and high in cost. The alternating-current demagnetization is realized by applying an alternating magnetic field with higher change frequency and slowly reduced magnetic field strength to a magnet until the residual magnetism is zero, namely, the original residual magnetism of the magnet is firstly demagnetized to be low enough by a direct-current reverse magnetic field with enough strength, and then the residual magnetism is completely demagnetized by an alternating magnetic field generated by power frequency low-voltage current. The compound demagnetization method is characterized in that the original residual magnetic flux of the magnet is faded to be low enough through a direct current reverse magnetic field with enough strength, then the residual magnetic flux is completely eliminated through an alternating magnetic field generated by a power frequency low-voltage current, the process is complicated by adopting the compound demagnetization method, and the demagnetization speed is low.
Therefore, the current demagnetization method is time-consuming, high in cost and low in accuracy, and in order to improve the demagnetization efficiency of the transformer, the invention provides the demagnetization system.
Fig. 1 is a structural diagram of a demagnetization system according to an embodiment of the present invention, as shown in fig. 1, the demagnetization system includes a controller 1, a full bridge circuit 2 and a current obtaining module 3, a first end and a second end of the full bridge circuit 2 are respectively connected to a first end and a second end of a transformer 4, and the second end of the full bridge circuit 2 and the common end of the second end of the transformer 4 are connected with the current acquisition module 3, in addition, the current acquisition module 3 is also connected with the controller 1, used for obtaining the secondary current measurement value of the transformer 4, the controller 1 is connected with the control end of the full bridge circuit 2, when the core of the transformer 4 is saturated, the controller 1 controls the output voltage of the full bridge circuit 2 to be changed from a forward voltage to a reverse voltage, and when the current secondary side current value reaches a preset current value, the full bridge circuit 2 is controlled to stop outputting reverse voltage, so that the magnetic flux density and the magnetic flux intensity gradually become zero to realize demagnetization of the transformer 4.
The first end of the full-bridge circuit 2 is a common end formed by connecting the first end of the first switch tube Q1 and the second end of the second switch tube Q2, and the second end of the full-bridge circuit 2 is a common end formed by connecting the second end of the third switch tube Q3 and the first end of the fourth switch tube Q2.
It should be noted that the current obtaining module 3 may be an ammeter that directly reads the current secondary-side current of the transformer 4, or may be a voltmeter that obtains the voltage of the transformer 4 and determines the current secondary-side current of the transformer 4 through calculation, and of course, may be another element as long as the current secondary-side current of the transformer 4 can be obtained, and thus, the current obtaining module 3 is not limited in the present invention. In addition, it should be noted that the first switching tube, the second switching tube, the third switching tube and the fourth switching tube in the full-bridge circuit 2 are all triodes with body diodes, and the specific structure of the full-bridge circuit 2 is not limited in the present invention.
In order to prevent the secondary side of the transformer 4 from being open-circuited due to misoperation of the full-bridge circuit 2, the demagnetization system provided by the invention further comprises a switching device, wherein one end of the switching device is connected with the common end of the first end of the full-bridge circuit 2 and the first end of the transformer 4, and the other end of the switching device is connected with the current acquisition module 3.
For convenience of understanding, the following detailed description will be made with reference to fig. 2, and fig. 2 is a schematic diagram of a B-H hysteresis curve based on a J-a hysteresis model provided in an embodiment of the present invention, as shown in fig. 2, point a is an initial magnetic flux of the transformer 4, point B is a saturation magnetic flux, point C is a residual magnetic flux density Br, point D is a coercive force point, and point E is determined by iterative calculation according to the J-a model. It should be noted that point a is a starting point when the transformer 4 generates residual magnetic flux, and fig. 2 is an illustration, where the position of the specific starting point a is at different positions on the ordinate B according to how much residual magnetic flux is actually generated by the transformer 4.
When the transformer 4 generates residual magnetic flux, the controller 1 controls the full-bridge circuit 2 to apply forward voltage to the secondary side of the transformer 4 when the switching device S1 is turned off, so that the magnetic flux of the iron core is increased to a point B at the saturation point, after the iron core is saturated, the controller 1 controls the full-bridge circuit 2 to apply reverse voltage, when the current value of the secondary side of the transformer 4 acquired by the current acquisition module 3 reaches a preset current value, namely when the magnetic flux of the iron core is reduced from the point B to the point E along the hysteresis curve, the point E is determined by iterative calculation according to the J-a hysteresis model, namely when the point E is a point corresponding to the preset current value, the controller 1 controls the switching device S1 to be closed, and when the magnetic flux density B and the magnetic field strength H are both reduced to zero, namely, the demagnetization is completed when the point E is reduced to the point F.
It should be noted that, after the current acquisition module 3 acquires the current secondary side current value of the transformer 4, the current acquisition module compares the current secondary side current value with a preset current value to determine whether the current secondary side current value reaches the preset current value, and if the current secondary side current value reaches the preset current value, the full-bridge circuit 2 is controlled to stop outputting the reverse voltage. The preset current value is obtained by calculating a J-A hysteresis model, and the model comprises 5 basic parameters: saturation magnetization MsThe shape parameter a of the anhysteretic magnetization curve, the irreversible loss coefficient k, the reversible magnetization coefficient c and the magnetic domain internal coupling average field parameter alpha.
Arbitrarily giving saturation magnetization MsThe shape parameter a, irreversible loss coefficient k, reversible magnetization coefficient c of the anhysteretic magnetization curve and the magnetic domain internal coupling average field parameter alpha are an initial value, saturation magnetization MsThe saturation sharp points of different hysteresis loops obtained by multiple groups of measurement are determined by least square fitting, and then 5 basic parameters of the J-A hysteresis model are obtained by continuously iterative calculation of the following formulas (1) - (5), wherein suffixes in, C, r and ta respectively represent a starting point A, a coercive point D, a remanence point C and a vertex B in a B-H curve of FIG. 2.
Wherein x is(in)The initial magnetic susceptibility corresponding to the starting point a in fig. 2.
Wherein M isan(c)The magnetization without hysteresis effect, x, corresponding to the coercive point D point in FIG. 2(c)The magnetic susceptibility, x, corresponding to the coercive point D point in FIG. 2an(c)The susceptibility of the coercive points D in FIG. 2 to the hysteresis-free effect is shown.
Wherein M is(r)The remanence point intensity, M, corresponding to the remanence point C in FIG. 2an(r)The magnetization without hysteresis effect, x, corresponding to the point C of the remanence point in FIG. 2(r)The magnetic susceptibility, x, corresponding to the point C of the remanence point in FIG. 2an(r)The susceptibility of the remanence point C in FIG. 2 without hysteresis effect is shown.
Wherein M is(ta)The intensity of the remanence point corresponding to the B point of the vertex in FIG. 2, Man(ta)The magnetization without hysteresis effect, x, corresponding to the point B at the top point in FIG. 2(ta) The magnetic susceptibility corresponding to the vertex B in fig. 2.
Wherein x isanThe magnetic susceptibility is free from hysteresis effect.
Wherein M isirrIs irreversible magnetization, mu0Is a vacuum magnetic permeability.
Where δ is a directional coefficient.
He＝H+αM (10)
Wherein R issecIs a secondary side resistance isecIs a secondary side current, NsecThe number of turns on the secondary side is,
is a core flux. In the core, the relationship between the current and the magnetic field strength is:
l is the length of the iron core, A is the cross-sectional area of the iron core,
derived from the J-A model by substituting U in formula (14)secSet to 0, H can be solvedsecAnd Isec，HsecI.e., the coercivity at point D in fig. 2, Isec is the magnetization current for reaching point E.
When the magnetic flux density point of the iron core is E, a power supply U is appliedsecSet to 0, the magnetic flux density and the magnetic flux intensity of the transformer 4 move from point E to point F due to inertia. Thus, will UsecWhen the value is set to 0, the obtained H size is HsecFurther, the compound represented by the formula (13) is represented by the formula Isec。
The demagnetization system provided by the embodiment of the invention comprises: the device comprises a controller, a full-bridge circuit and a current acquisition module. The first end of full-bridge circuit is connected with the first end of transformer, the second end of full-bridge circuit is connected with the second end of transformer, and the common terminal is connected with the current acquisition module, the current acquisition module still is connected with the controller for gather the current secondary survey current value of transformer, in addition, the controller is connected with the control end of full-bridge circuit, be used for when the iron core of transformer is saturated, the output voltage of control full-bridge circuit is changed into reverse phase voltage by the forward voltage, and when current secondary side current value reached and predetermines the current value, control full-bridge circuit stopped output voltage. Therefore, according to the technical scheme provided by the invention, when the iron core of the transformer is saturated, the output voltage of the full-bridge circuit is controlled by the controller to be changed from the forward voltage to the reverse voltage so as to reduce the magnetic flux intensity and the magnetic flux density of the transformer, and when the current secondary side current of the transformer reaches the preset current value, the full-bridge circuit is controlled to stop outputting the voltage so as to realize demagnetization of the transformer, so that the demagnetization of the transformer is quickly and accurately realized by changing the voltage applied to the transformer, and the demagnetization efficiency of the transformer is improved.
In a specific embodiment, the secondary side of the transformer in normal operation is generally connected to a power consumer, and if the full-bridge circuit is operated by mistake, the secondary side of the transformer is open, a power failure occurs, and normal power supply is affected, so that to avoid the open circuit of the secondary side of the transformer, a switch device is additionally arranged in the demagnetization system provided by the embodiment of the invention, as shown in fig. 2, one end of the switch device S1 is connected with a common end of the first end of the transformer and the first end of the full-bridge circuit, the common end is further connected with the controller, and the other end is connected with the current acquisition module.
When the transformer normally works, the switching device S1 is closed, the full-bridge circuit can not be accessed to the circuit, when the converter needs demagnetization, the controller sends out an instruction, the switching device S1 is controlled to be disconnected, and the full-bridge circuit is controlled to apply forward voltage until the transformer core is saturated, reverse voltage is applied through the controller again, current secondary side current value of the transformer reaches preset current value, at the moment, the controller controls the full-bridge circuit to stop outputting voltage, until magnetic flux intensity and magnetic flux density are reduced to zero, the controller sends out an instruction again to close the switch S1, and demagnetization is completed.
According to the demagnetization system provided by the embodiment of the invention, the switch device is additionally arranged, so that the secondary side of the transformer is prevented from being opened, the power failure fault is avoided, the normal power supply is ensured, and meanwhile, when the transformer is demagnetized, the full-bridge circuit is prevented from being mistakenly operated to influence demagnetization, so that the demagnetization efficiency is improved.
In an implementation, as shown in fig. 2, the full bridge circuit includes a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, and a voltage source U. The control end of the first switch tube Q1, the control end of the second switch tube Q2, the control end of the third switch tube Q3 and the control end of the fourth switch tube Q4 are all connected with the controller, the first end of the first switch tube Q1 is connected with the second end of the second switch tube Q2, the common end is used as the first end of the full bridge circuit, the first end of the full bridge circuit is connected with one end of the transformer, the second end of the first switch tube Q1 is connected with the first end of the third switch tube Q3, the common end is connected with one end of the voltage source U, the first end of the second switch tube Q2 is connected with the second end of the fourth switch tube Q4, the common end is connected with the other end of the voltage source U, the second end of the third switch tube Q3 is connected with the first end of the fourth switch tube Q4, the common end is used as the second end of the full bridge circuit, and the first end of the full bridge circuit is connected with the other end of the transformer.
As shown in fig. 2, the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 of the full bridge circuit are all transistors with body diodes, but the invention is not limited to the structure of the full bridge circuit. Two ends of the first diode D1 are connected to the first end and the second end of the first switch tube Q1, two ends of the second diode D2 are connected to the first end and the second end of the second switch tube Q2, two ends of the third diode D3 are connected to the first end and the second end of the third switch tube Q3, and two ends of the fourth diode D4 are connected to the first end and the second end of the first switch tube Q4.
In specific implementation, when the transformer normally works, the switching device S1 is closed, the full-bridge circuit does not output voltage, when the switching device S1 is opened, the controller controls the full-bridge circuit to output forward voltage, when the transformer core is saturated, the controller controls the voltage output by the full-bridge circuit to have the forward voltage to become reverse voltage, at this moment, when the current secondary side current obtained by the current obtaining module from the transformer reaches a preset current value, the controller controls the full-bridge circuit to stop outputting the reverse voltage, so that the magnetic flux intensity and the magnetic flux density are reduced to zero to complete demagnetization.
According to the demagnetization system provided by the embodiment of the invention, the full-bridge circuit is controlled by the controller to apply voltage to the transformer core, so that demagnetization of the transformer is quickly and accurately realized, and the demagnetization efficiency of the transformer is improved.
In the foregoing embodiment, a demagnetization system is described in detail, and the present application also provides an embodiment corresponding to the demagnetization method. Fig. 3 is a flowchart of a demagnetization method according to an embodiment of the present invention, and as shown in fig. 3, the method includes:
s10: and acquiring the current secondary side current value of the transformer.
S11: it is determined whether or not the core of the transformer is saturated, and if saturated, the process proceeds to step S12.
S12: the output voltage of the full bridge circuit is controlled to change from a forward voltage to a reverse voltage.
S13: and determining whether the current secondary side current value reaches a preset current value, and if so, entering the step S14.
S14: and controlling the full-bridge circuit to stop outputting the voltage.
In a specific embodiment, the controller first obtains a current value of a front side and a secondary side of the transformer, and determines whether an iron core of the transformer is saturated, if the iron core of the transformer is saturated, the controller proceeds to step S12 to control an output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage, then determines whether the obtained current value of the secondary side of the transformer reaches a preset current value, and if the current value of the secondary side of the transformer reaches the preset current value, the controller proceeds to step S14 to control the full-bridge circuit to stop outputting the voltage, thereby implementing demagnetization of the transformer.
It should be noted that, when determining whether the current secondary side current value of the transformer reaches a preset current value, the preset current value is obtained by calculation according to the J-a hysteresis model. The specific calculation method for determining the preset current value through the J-a hysteresis model is described in detail in the embodiment corresponding to the demagnetization system, and reference may be made to the description of the embodiment corresponding to the demagnetization system, which is not repeated herein.
The demagnetization method provided by the embodiment of the invention comprises the steps of obtaining the current values of the front side and the secondary side of the transformer, judging whether an iron core of the transformer is saturated or not, if the iron core of the transformer is saturated, controlling the output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage, and controlling the full-bridge circuit to stop outputting the voltage when the current values of the front side and the secondary side of the transformer reach the preset current value so as to facilitate the magnetic flux intensity and the magnetic flux density to be reduced to zero to complete demagnetization of the transformer. Therefore, according to the technical scheme provided by the invention, when the iron core of the transformer is saturated, the output voltage of the full-bridge circuit is controlled by the controller to be changed from the forward voltage to the reverse voltage so as to reduce the magnetic flux intensity and the magnetic flux density of the transformer, and when the current secondary side current of the transformer reaches the preset current value, the full-bridge circuit is controlled to stop outputting the voltage so as to realize demagnetization of the transformer, so that the demagnetization of the transformer is quickly and accurately realized by changing the voltage applied to the transformer, and the demagnetization efficiency of the transformer is improved.
In a specific embodiment, the controller determines a current secondary side current value corresponding to a current iron core saturation through calculation, acquires the current secondary side current value of the transformer in a demagnetization process, judges whether the current secondary side current value is equal to a saturated secondary measured current value, and if the current secondary side current value is equal to the saturated secondary measured current value, determines that the transformer is saturated, and controls the voltage applied to the transformer to be changed from a forward voltage to a reverse voltage. And then determining a preset current value based on the J-A hysteresis model, and when the current values of the front side and the secondary side of the transformer reach the preset current value, controlling the full-bridge circuit to stop outputting reverse voltage to the transformer by the controller, wherein the flux density and the flux intensity of the transformer are gradually reduced due to inertia until the flux density and the flux intensity are reduced to zero, so that demagnetization of the transformer is realized.
According to the demagnetization method provided by the embodiment of the invention, when the transformer generates residual magnetic flux, the controller controls the full-bridge circuit to apply forward voltage to the secondary side of the transformer, so that the magnetic flux of the iron core is increased to a saturation point, after the iron core is saturated, the controller controls the full-bridge circuit to apply reverse voltage, when the current value of the current secondary side of the transformer, which is acquired by the current acquisition module, reaches a preset current value, the controller controls the full-bridge circuit to stop outputting the reverse voltage, and when the magnetic flux density and the magnetic field intensity are both reduced to zero, demagnetization is finished. Therefore, according to the technical scheme provided by the invention, the B-H hysteresis curve of the transformer is determined by using the J-A hysteresis model, the detailed specification parameters of the transformer do not need to be known, the residual magnetic flux of the iron core is accurately and quickly eliminated, and the demagnetization efficiency of the transformer is improved.
In the foregoing embodiments, detailed descriptions are given for demagnetization methods, and the present application also provides embodiments corresponding to demagnetization devices. It should be noted that the present application describes the embodiments of the apparatus portion from two perspectives, one is based on the functional module, and the other is based on the hardware structure.
Fig. 4 is a structural diagram of a demagnetizing device provided in an embodiment of the present invention, and as shown in fig. 4, the demagnetizing device includes:
and the obtaining module 10 is used for obtaining the current secondary side current value of the transformer.
And the judging module 11 is used for judging whether the iron core of the transformer is saturated or not, and calling the first control module if the iron core of the transformer is saturated.
And a first control module 12 for controlling the output voltage of the full bridge circuit to change from the forward voltage to the reverse voltage.
And the determining module 13 is configured to determine whether the current secondary side current value reaches a preset current value, and if so, invoke the second control module.
And a second control module 14 for controlling the full bridge circuit to stop outputting the voltage.
Since the embodiments of the apparatus portion and the method portion correspond to each other, please refer to the description of the embodiments of the method portion for the embodiments of the apparatus portion, which is not repeated here.
The demagnetization device provided by the embodiment of the invention judges whether the iron core of the transformer is saturated or not by acquiring the current values of the front side and the secondary side of the transformer, controls the output voltage of the full-bridge circuit to be changed from the forward voltage to the reverse voltage if the iron core of the transformer is saturated, and controls the full-bridge circuit to stop outputting the voltage when the current values of the front side and the secondary side of the transformer reach the preset current value so as to facilitate the magnetic flux intensity and the magnetic flux density to be reduced to zero to complete the demagnetization of the transformer. Therefore, according to the technical scheme provided by the invention, when the iron core of the transformer is saturated, the output voltage of the full-bridge circuit is controlled by the controller to be changed from the forward voltage to the reverse voltage so as to reduce the magnetic flux intensity and the magnetic flux density of the transformer, and when the current secondary side current of the transformer reaches the preset current value, the full-bridge circuit is controlled to stop outputting the voltage so as to realize demagnetization of the transformer, so that the demagnetization of the transformer is quickly and accurately realized by changing the voltage applied to the transformer, and the demagnetization efficiency of the transformer is improved.
Fig. 5 is a structural diagram of a demagnetizing device according to another embodiment of the present invention, and as shown in fig. 5, the demagnetizing device includes: a memory 20 for storing a computer program;
a processor 21, configured to execute the computer program to implement the steps of the demagnetization method as mentioned in the above embodiments.
The demagnetization device provided in this embodiment may include, but is not limited to, a smart phone, a tablet computer, a notebook computer, or a desktop computer.
The processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The processor 21 may be implemented in at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), and Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor, where the main processor is a processor for Processing data in an awake state, and is also called a Central Processing Unit (CPU); a coprocessor is a low power processor for processing data in a standby state. In some embodiments, the processor 21 may be integrated with an image processor (GPU), and the GPU is responsible for rendering and drawing the content required to be displayed by the display screen. In some embodiments, the processor 21 may further include an Artificial Intelligence (AI) processor for processing computing operations related to machine learning.
The memory 20 may include one or more computer-readable storage media, which may be non-transitory. Memory 20 may also include high speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used for storing the following computer program 201, wherein after being loaded and executed by the processor 21, the computer program can implement the relevant steps of the demagnetization method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202, data 203, and the like, and the storage manner may be a transient storage manner or a permanent storage manner. Operating system 202 may include, among others, Windows, Unix, Linux, and the like. Data 203 may include, but is not limited to, related data involved in demagnetization methods, and the like.
In some embodiments, the demagnetization device may further include a display screen 22, an input/output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.
It will be appreciated by those skilled in the art that the arrangement shown in figure 5 does not constitute a limitation of the demagnetising apparatus and may include more or fewer components than those shown.
The demagnetization device provided by the embodiment of the application comprises a memory and a processor, wherein when the processor executes a program stored in the memory, the following method can be realized: and (5) a demagnetization method.
The demagnetization device provided by the embodiment of the invention can be used for obtaining the current values of the front side and the secondary side of the transformer and judging whether the iron core of the transformer is saturated or not, if the iron core of the transformer is saturated, controlling the output voltage of the full-bridge circuit to be changed from the forward voltage to the reverse voltage, and controlling the full-bridge circuit to stop outputting the voltage when the current values of the front side and the secondary side of the transformer reach the preset current value, so that the magnetic flux intensity and the magnetic flux density are reduced to zero to complete the demagnetization of the transformer, the detailed specification parameters of the transformer are not required to be known, the residual magnetic flux of the iron core can be accurately and quickly eliminated, and the demagnetization efficiency of the transformer is improved.
Finally, the application also provides a corresponding embodiment of the computer readable storage medium. The computer-readable storage medium has stored thereon a computer program which, when being executed by a processor, carries out the steps as set forth in the above-mentioned method embodiments.
It is to be understood that if the method in the above embodiments is implemented in the form of software functional units and sold or used as a stand-alone product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which is stored in a storage medium and executes all or part of the steps of the methods described in the embodiments of the present application, or all or part of the technical solutions. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
A demagnetization system, a demagnetization method, a demagnetization device, and a demagnetization medium provided by the present application are described in detail above. The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.
It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Claims (10)
1. A demagnetization system, applied to a transformer, comprising: the device comprises a controller, a full-bridge circuit and a current acquisition module;
the first end and the second end of the full-bridge circuit are respectively connected with the first end and the second end of the transformer, and the common end of the second end of the full-bridge circuit and the second end of the transformer is connected with the current acquisition module;
the current acquisition module is connected with the controller and used for acquiring the current secondary measured current value of the transformer;
the controller is connected with the control end of the full-bridge circuit and used for controlling the output voltage of the full-bridge circuit to be changed from forward voltage to reverse voltage when the iron core of the transformer is saturated, and controlling the full-bridge circuit to stop outputting the voltage when the current secondary side current value reaches a preset current value.
2. Demagnetization system according to claim 1, further comprising a switching device;
one end of the switching device is connected with the common end of the first end of the full-bridge circuit and the first end of the transformer, and the other end of the switching device is connected with the common end of the second end of the full-bridge circuit and the second end of the transformer.
3. The demagnetization system of claim 2, wherein the full bridge circuit comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a voltage source;
the control end of the first switching tube, the control end of the second switching tube, the control end of the third switching tube and the control end of the fourth switching tube are connected with the controller;
the first end of first switch tube with the second end of second switch tube is connected, and the common port conduct the first end of full-bridge circuit, the second end of first switch tube with the first end of third switch tube is connected, and the common port with the one end of voltage source is connected, the first end of second switch tube with the second end of fourth switch tube is connected, and the common port with the other end of voltage source is connected, the second end of third switch tube with the first end of fourth switch tube is connected, and the common port conduct the second end of full-bridge circuit.
4. The demagnetization system of claim 3, wherein the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all triodes with body diodes.
5. A demagnetization method, applied to the demagnetization system according to any one of claims 1 to 4, comprising:
acquiring the current secondary side current value of the transformer;
judging whether an iron core of the transformer is saturated or not, and if so, controlling the output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage;
and determining whether the current secondary side current value reaches a preset current value, and if so, controlling the full-bridge circuit to stop outputting the voltage.
6. A demagnetization method according to claim 5 wherein the predetermined current value is calculated according to a J-A hysteresis model.
7. A demagnetization method according to claim 5, wherein the determination of whether the core of the transformer is saturated comprises:
calculating a saturated secondary measured current value when an iron core of the transformer is saturated;
and judging whether the current secondary side current value is equal to the saturated secondary measured current value or not, and if so, determining that the iron core of the transformer is saturated.
8. A demagnetization device, comprising:
the acquisition module is used for acquiring the current secondary side current value of the transformer;
the judging module is used for judging whether the iron core of the transformer is saturated or not, and if the iron core of the transformer is saturated, the first control module is called;
the first control module is used for controlling the output voltage of the full-bridge circuit to be changed from a forward voltage to a reverse voltage;
the determining module is used for determining whether the current secondary side current value reaches a preset current value or not, and if so, calling the second control module;
and the second control module is used for controlling the full-bridge circuit to stop outputting the voltage.
9. A demagnetization device, comprising a memory for storing a computer program;
a processor for implementing the steps of the demagnetization method according to any of claims 5 to 7 when executing the computer program.
10. A computer-readable storage medium, having stored thereon a computer program which, when being executed by a processor, implements the steps of the demagnetization method according to any one of claims 5 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111516277.6A CN114141471B (en) | 2021-12-08 | 2021-12-08 | Demagnetizing system, method, device and medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111516277.6A CN114141471B (en) | 2021-12-08 | 2021-12-08 | Demagnetizing system, method, device and medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114141471A true CN114141471A (en) | 2022-03-04 |
| CN114141471B CN114141471B (en) | 2023-12-05 |
Family
ID=80385763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111516277.6A Active CN114141471B (en) | 2021-12-08 | 2021-12-08 | Demagnetizing system, method, device and medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114141471B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000031658A (en) * | 1998-11-09 | 2000-06-05 | 이구택 | Apparatus for restraining transformer from generating exciting inrush current and method thereof |
| JP2011216630A (en) * | 2010-03-31 | 2011-10-27 | Takaoka Electric Mfg Co Ltd | Method and device for controlling density of residual magnetic fluxes in transformer iron core |
| CN103632804A (en) * | 2013-12-11 | 2014-03-12 | 国家电网公司 | Method and system for degaussing power transformer |
| CN105118606A (en) * | 2015-09-11 | 2015-12-02 | 浙江大学 | Demagnetizing circuit and method for removing residual magnetism of electromagnetic current transformer on line |
| CN105280331A (en) * | 2015-11-06 | 2016-01-27 | 西安交通大学 | Transformer iron core demagnetization method |
| CN105425175A (en) * | 2015-12-08 | 2016-03-23 | 云南电力试验研究院(集团)有限公司 | Iron core remanent magnetism elimination and measurement method based on polarity-reversal DC voltage source |
| CN106291407A (en) * | 2016-08-01 | 2017-01-04 | 国网河北省电力公司电力科学研究院 | A kind of transformator remanent magnetism detection, elimination integrated apparatus and using method thereof |
| CN108781039A (en) * | 2016-03-25 | 2018-11-09 | 松下知识产权经营株式会社 | Mode of resonance power inverter and abnormality determination method |
| CN110994573A (en) * | 2019-11-22 | 2020-04-10 | 重庆市送变电工程有限公司 | Leakage protection circuit based on transformer reversal polarity demagnetization method |
| US20200126706A1 (en) * | 2018-10-19 | 2020-04-23 | State Grid Jiangsu Electric Power Co.,Ltd. Research Institute | Device for evaluating and demagnetizing residual magnetism quantity of power transformer and control method thereof |
-
2021
- 2021-12-08 CN CN202111516277.6A patent/CN114141471B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000031658A (en) * | 1998-11-09 | 2000-06-05 | 이구택 | Apparatus for restraining transformer from generating exciting inrush current and method thereof |
| JP2011216630A (en) * | 2010-03-31 | 2011-10-27 | Takaoka Electric Mfg Co Ltd | Method and device for controlling density of residual magnetic fluxes in transformer iron core |
| CN103632804A (en) * | 2013-12-11 | 2014-03-12 | 国家电网公司 | Method and system for degaussing power transformer |
| CN105118606A (en) * | 2015-09-11 | 2015-12-02 | 浙江大学 | Demagnetizing circuit and method for removing residual magnetism of electromagnetic current transformer on line |
| CN105280331A (en) * | 2015-11-06 | 2016-01-27 | 西安交通大学 | Transformer iron core demagnetization method |
| CN105425175A (en) * | 2015-12-08 | 2016-03-23 | 云南电力试验研究院(集团)有限公司 | Iron core remanent magnetism elimination and measurement method based on polarity-reversal DC voltage source |
| CN108781039A (en) * | 2016-03-25 | 2018-11-09 | 松下知识产权经营株式会社 | Mode of resonance power inverter and abnormality determination method |
| CN106291407A (en) * | 2016-08-01 | 2017-01-04 | 国网河北省电力公司电力科学研究院 | A kind of transformator remanent magnetism detection, elimination integrated apparatus and using method thereof |
| US20200126706A1 (en) * | 2018-10-19 | 2020-04-23 | State Grid Jiangsu Electric Power Co.,Ltd. Research Institute | Device for evaluating and demagnetizing residual magnetism quantity of power transformer and control method thereof |
| CN110994573A (en) * | 2019-11-22 | 2020-04-10 | 重庆市送变电工程有限公司 | Leakage protection circuit based on transformer reversal polarity demagnetization method |
Non-Patent Citations (1)
| Title |
|---|
| 李景丽;贺鹏威;邱再森;郭丽莹;李渊博;: "电力变压器铁心剩磁测量方法研究综述", 高压电器, no. 07 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114141471B (en) | 2023-12-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Rudez et al. | Sympathetic inrush current phenomenon with loaded transformers | |
| Ge et al. | Residual flux in the closed magnetic core of a power transformer | |
| CN107703368B (en) | Method for measuring inductance of transformer in deep saturation state | |
| Rezaei-Zare et al. | An accurate current transformer model based on Preisach theory for the analysis of electromagnetic transients | |
| Ribas et al. | Modeling ferroresonance phenomena with a flux-current Jiles-Atherton hysteresis approach | |
| CN104833928A (en) | Large-scale power transformer residual magnetism detection method | |
| Zhang et al. | Differential evolution based parameter identification of static and dynamic JA models and its application to inrush current study in power converters | |
| Solovev et al. | Current transformers: Transfer functions, frequency response, and static measurement error | |
| Jia et al. | Simulation method for current-limiting effect of saturated-core superconducting fault current limiter | |
| He et al. | Sensor fault diagnosis of superconducting fault current limiter with saturated iron core based on SVM | |
| Corrodi et al. | Influence of system transients on the residual flux of an unloaded transformer | |
| Vanti et al. | Semianalytic solution for a simple model of inrush currents in transformers | |
| CN114141471A (en) | Demagnetization system, method, device and medium | |
| He et al. | Control system modeling and simulation of superconducting current limiter with saturated iron core controlled by dc bias current | |
| CN104483639A (en) | Residual magnetism estimation method for non-fault tripping of YNd11 type three-phase combined transformer | |
| JP5594726B2 (en) | Method and apparatus for controlling residual magnetic flux density of transformer core | |
| Duan et al. | Modeling and experimental validation of a dynamic regional saturation JA model for protective current transformer | |
| CN107102229B (en) | Method for realizing transformer model for no-load switching transient calculation | |
| Corea-Araujo et al. | Validation of single-phase transformer model for ferroresonance analysis | |
| Chong et al. | A novel concept for a fault current limiter | |
| Beyranvand et al. | Finite element study of ferroresonance in single-phase transformers considering magnetic hysteresis | |
| Li et al. | Novel remanence detection for power transformers based on modified JA model | |
| Gou et al. | Simulation analysis of spatial electromagnetic field of transformer core considering nonlinear BH curve | |
| Ozgonenel et al. | Current transformer modeling for compensating algorithms | |
| Ge et al. | Simulation and impact analysis of remanent flux on power transformer inrush current |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |