CN114019286B - Transformer direct-current magnetic bias tolerance capability checking field test method and system - Google Patents
Transformer direct-current magnetic bias tolerance capability checking field test method and system Download PDFInfo
- Publication number
- CN114019286B CN114019286B CN202111306186.XA CN202111306186A CN114019286B CN 114019286 B CN114019286 B CN 114019286B CN 202111306186 A CN202111306186 A CN 202111306186A CN 114019286 B CN114019286 B CN 114019286B
- Authority
- CN
- China
- Prior art keywords
- transformer
- power supply
- magnetic
- current
- time
- 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.)
- Active
Links
- 238000010998 test method Methods 0.000 title claims description 5
- 230000004907 flux Effects 0.000 claims abstract description 75
- 238000000034 method Methods 0.000 claims abstract description 73
- 238000012360 testing method Methods 0.000 claims abstract description 37
- 230000005284 excitation Effects 0.000 claims abstract description 30
- 230000008569 process Effects 0.000 claims description 17
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 14
- 238000004364 calculation method Methods 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 9
- 238000001514 detection method Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 10
- 238000002347 injection Methods 0.000 description 8
- 239000007924 injection Substances 0.000 description 8
- 238000004590 computer program Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/003—Environmental or reliability tests
Abstract
The invention discloses a method and a system for checking DC magnetic bias tolerance of a transformer in field test, wherein the method comprises the following steps: step 1, carrying out direct current magnetic bias tolerance test wiring: one side of the transformer is open, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply; step 2, initializing the return of the magnetic flux of the transformer core to zero; step 3, detecting the DC magnetic bias tolerance of the transformer: the power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects current, and the current is processed in real time through collected data to form a real-time excitation curve of the transformer core; pressurizing the transformer to enable the real-time slope of the transformer core curve to reach a preset value, and stopping pressurizing; and calculates the DC bias tolerance of the transformer at this time. The invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site.
Description
Technical Field
The invention relates to the technical field of high-voltage test methods, in particular to a method and a system for checking DC magnetic bias tolerance capability of a transformer.
Background
At present, extra-high voltage direct current engineering and railway track traffic are built positively, and both the monopolar earth operation of the extra-high voltage direct current and the track direct current leakage current of the railway track traffic cause the direct current magnetic bias of a transformer. The transformer excitation loop tends to be saturated due to the influence of direct current magnetic bias, the transformer excitation impedance is greatly reduced, the excitation current is increased, the transformer loss, vibration and heating are aggravated, and the transformer is damaged.
In order to avoid the influence of DC magnetic bias on the transformer, the transformer is required to have DC magnetic bias tolerance in the region with DC magnetic bias. The existing method for checking the DC magnetic bias tolerance of the transformer adopts a power frequency injection DC mode to test, two transformer tested products with consistent capacity and other performances are needed, the capacity of a test power supply is far greater than the no-load capacity of the transformer, the requirement on test conditions is high, and the method has no feasibility in field checking. At present, a transformer direct current magnetic bias tolerance test method easy to implement on site is lacking.
Disclosure of Invention
The technical problem to be solved by the invention is that the existing method for checking the DC magnetic bias tolerance of the transformer adopts a power frequency injection DC mode to test, two transformer tested products with consistent capacity and other performances are needed, the capacity of a test power supply is far greater than the no-load capacity of the transformer, the requirement on test conditions is higher, and the method has no feasibility in field checking.
The invention aims to provide a method and a system for checking the DC magnetic bias tolerance of a transformer. The invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site, ensures that the requirement of the magnetic bias tolerance capacity of the transformer excitation is reliably executed, and improves the operation reliability of the transformer.
The invention is realized by the following technical scheme:
in a first aspect, the invention provides a method for checking the DC magnetic bias tolerance of a transformer, which comprises the following steps:
Step 1, carrying out direct current magnetic bias tolerance test wiring: one side of the transformer is open, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
step 2, initializing the return of the magnetic flux of the transformer core to zero;
Step 3, detecting the DC magnetic bias tolerance of the transformer: the power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects the current i, and the real-time excitation curve of the transformer core is formed through real-time processing of collected data; pressurizing the transformer to enable the real-time slope k of the transformer core curve to reach a preset value, and stopping pressurizing; and calculates the DC bias tolerance of the transformer at this time.
The working principle is as follows: the method for checking the DC magnetic bias tolerance capability of the transformer based on the prior art adopts a power frequency injection DC mode to test, two transformer tested products with consistent capacity and other performances are needed, the capacity of a test power supply is far greater than the no-load capacity of the transformer, the requirement on test conditions is high, and the method has no feasibility in field checking. The invention designs a method for checking the DC magnetic bias tolerance of a transformer, which is easy to implement on site and can detect the DC magnetic bias tolerance of the transformer on site through controllable wave voltage source injection and current detection. The invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site, ensures that the requirement of the magnetic bias tolerance capacity of the transformer excitation is reliably executed, and improves the operation reliability of the transformer.
Compared with the prior art, the invention has the beneficial effects that: (1) The method for checking the DC magnetic bias tolerance capability of the transformer by the existing laboratory DC superposition power frequency technology has huge equipment, and the method provided by the invention simplifies test equipment. (2) At present, the power grid puts a DC magnetic bias tolerance requirement on the transformer, no method is used for executing the test of the capability requirement on site, and the method can change the current situation. (3) By using the method of the invention, before and after the detection of the DC bias current tolerance value of the transformer, the magnetic flux of the transformer core is required to be zeroed, so that the magnetizing inrush current of the transformer during operation can be reduced.
Further, the initialization of the magnetic flux return of the transformer core in the step 2 specifically comprises the following steps:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A (or 10A), enabling the magnetic flux psi m of the transformer iron core to reach a positive magnetic saturation state;
Controlling a controllable wave power supply to output-U voltage, and enabling a transformer iron core magnetic flux psi m to reach a negative magnetic saturation state when the current detected by a current sensor reaches-5A (or-10A);
Recording the time 2T when the magnetic flux psi m of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
And starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
The square wave controllable source voltage applying process is shown in fig. 4, and the magnetic flux change of the transformer core is shown in fig. 5; the process of applying + -U with a gradual decay of 50% starting at 1.5T time includes four steps, as follows:
The first step: applying positive voltage 1.5T from the negative magnetic saturation state of the transformer, wherein the magnetic flux point of the transformer reaches +0.5ψ m;
And a second step of: applying a negative voltage of 0.75T from transformer flux +0.5 ψ m, transformer flux point reaching-0.25 ψ m;
And a third step of: applying a positive voltage of 0.375T from transformer flux-0.25 ψ m, the transformer flux point reaching +0.125 ψ m;
Fourth step: the negative voltage of 0.1875T is applied from the transformer magnetic flux +0.125 psi m, the transformer magnetic flux point reaches-0.0625 psi m, and the transformer magnetic return to zero is finished.
Further, the calculation formula of the real-time slope k of the transformer core curve in the step 3 is as follows:
∫Udt＝Ψ (1)
k＝dΨ/di (2)
wherein, ψ refers to flux linkage, which is obtained by integrating and calculating the output voltage +U of the controllable wave power supply to the time t; k represents the real-time slope of the transformer core curve, and is obtained by calculating the derivative of the flux linkage ψ on the current i detected by the current sensor.
Further, the calculation formula of the dc bias tolerance value I p of the transformer in step 3 is:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value by pressurizing the transformer; i 0 denotes a rated no-load current value of the transformer.
Further, the rated no-load current value I 0 of the transformer is obtained by inquiring the nameplate parameters of the transformer.
Further, the preset value in the step 3 is k 0/3, where k 0 represents an initial value of a slope of the real-time excitation curve of the transformer core.
Further, the method further comprises a step 4 after the step 3, and the magnetic flux of the transformer core is zeroed.
In a second aspect, the invention further provides a system for checking the dc magnetic bias tolerance of a transformer, which supports the method for checking the dc magnetic bias tolerance of the transformer, and comprises a transformer, a controllable wave power supply, a current sensor and a power supply control unit; one side of the transformer is opened, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
The power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects the current i, and the real-time excitation curve of the transformer core is formed through real-time processing of collected data; pressurizing the transformer to enable the real-time slope k of the transformer core curve to reach a preset value, and stopping pressurizing; and calculating the DC magnetic bias tolerance value of the transformer at the moment, and detecting the DC magnetic bias tolerance capability of the transformer.
Furthermore, the magnetic flux of the iron core of the transformer needs to be zeroed before and after the DC magnetic bias tolerance capability detection of the transformer is carried out, so that the excitation surge current of the transformer during operation can be reduced; the execution process for zeroing the magnetic flux of the transformer core is as follows:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A (or 10A), enabling the magnetic flux of the transformer iron core to reach a positive magnetic saturation state;
controlling a controllable wave power supply to output-U voltage, and when the current detected by a current sensor reaches-5A (or-10A), enabling the magnetic flux of a transformer iron core to reach a negative magnetic saturation state;
recording the time 2T when the magnetic flux of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
And starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
Further, the calculation formula of the dc bias tolerance value I p of the transformer is:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value by pressurizing the transformer; i 0 represents a rated no-load current value of the transformer, and the rated no-load current value of the transformer is obtained by inquiring a nameplate parameter of the transformer; the preset value k 0/3,k0 represents the initial value of the slope of the real-time excitation curve of the transformer core.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the method for checking the DC magnetic bias tolerance capability of the transformer by the existing laboratory DC superposition power frequency technology has huge equipment, and the method provided by the invention simplifies test equipment.
2. At present, the power grid puts a DC magnetic bias tolerance requirement on the transformer, no method is used for executing the test of the capability requirement on site, and the method can change the current situation.
3. According to the method and the system, before and after the detection of the DC bias current tolerance value of the transformer, the magnetic flux of the iron core of the transformer is required to be zeroed, so that the excitation surge current of the transformer during operation can be reduced.
4. The invention designs a method and a system for checking the DC magnetic bias tolerance of the transformer, which are easy to implement on site, and can detect the DC magnetic bias tolerance of the transformer on site through controllable wave voltage source injection and current detection; the invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site, ensures that the requirement of the magnetic bias tolerance capacity of the transformer excitation is reliably executed, and improves the operation reliability of the transformer.
Drawings
The accompanying drawings, which are included to provide a further understanding of embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:
FIG. 1 is a flow chart of a method for checking DC magnetic bias tolerance of a transformer in field test according to the present invention.
Fig. 2 is a detailed flowchart of a method for checking the dc bias withstand capability of a transformer according to the present invention.
FIG. 3 is a wiring diagram of a field test system for checking DC bias withstand capability of a transformer according to the present invention.
FIG. 4 is a schematic diagram of a square wave controllable source voltage application process according to the present invention.
Fig. 5 is a diagram of a path of a return-to-zero excitation curve of a transformer core according to the present invention.
Fig. 6 is a real-time excitation curve of the transformer core of the present invention.
FIG. 7 is a schematic diagram of a square wave controllable source voltage application process according to the present invention.
Detailed Description
For the purpose of making apparent the objects, technical solutions and advantages of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present invention and the descriptions thereof are for illustrating the present invention only and are not to be construed as limiting the present invention.
Example 1
As shown in fig. 1 to 7, the method for checking the dc bias withstand capability of the transformer according to the present invention comprises the following steps, as shown in fig. 1 and 2:
Step 1, carrying out direct current magnetic bias tolerance test wiring: as shown in fig. 3, one side of the transformer is open, the other side of the transformer is sequentially connected in series with a controllable wave power supply and a current sensor, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
Step 2, initializing the return of the magnetic flux of the transformer core to zero; the method is characterized in that the initial magnetic flux of the transformer iron core is not in a zero position due to residual magnetism, and the iron core magnetic flux needs to be zeroed in a direct current magnetic bias tolerance capability detection test. The implementation method specifically comprises the following steps:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A, enabling the magnetic flux psi m of the transformer core to reach a positive magnetic saturation state;
Controlling a controllable wave power supply to output-U voltage, and enabling the magnetic flux psi m of the transformer core to reach a negative magnetic saturation state when the current detected by the current sensor reaches-5A;
Recording the time 2T when the magnetic flux psi m of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
And starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
The process of applying + -U with a gradual decay of 50% starting at 1.5T time includes four steps, as follows:
The first step: applying positive voltage 1.5T from the negative magnetic saturation state of the transformer, wherein the magnetic flux point of the transformer reaches +0.5ψ m;
And a second step of: applying a negative voltage of 0.75T from transformer flux +0.5 ψ m, transformer flux point reaching-0.25 ψ m;
And a third step of: applying a positive voltage of 0.375T from transformer flux-0.25 ψ m, the transformer flux point reaching +0.125 ψ m;
Fourth step: the negative voltage of 0.1875T is applied from the transformer magnetic flux +0.125 psi m, the transformer magnetic flux point reaches-0.0625 psi m, and the transformer magnetic return to zero is finished.
The square wave controllable source voltage application process is shown in fig. 4, and the transformer core magnetic flux change is shown in fig. 5.
Step 3, detecting the DC magnetic bias tolerance of the transformer: the power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects the current i, and the current i is processed in real time through collected data to form a real-time excitation curve of the transformer core, as shown in fig. 6; the initial point slope of the excitation curve of the transformer core is k 0, the transformer is pressurized, in the pressurizing process, the real-time slope k of the excitation curve of the transformer core is compared with the initial k 0, when k is k 0/3, the current value I is recorded, the pressurizing is stopped, and the pressurizing process is shown in fig. 7. And calculates the DC bias tolerance of the transformer at this time.
Specifically: the direct current magnetic bias tolerance test wiring is shown in fig. 3, one side of the transformer is open, and the other side is connected with a controllable wave power supply and a current sensor in series, signals of the current sensor are transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply.
The calculation formula of the real-time slope k of the transformer core curve is as follows:
∫Udt＝Ψ (1)
k＝dΨ/di (2)
wherein, ψ refers to flux linkage, which is obtained by integrating and calculating the output voltage +U of the controllable wave power supply to the time t; k represents the real-time slope of the transformer core curve, and is obtained by calculating the derivative of the flux linkage ψ on the current i detected by the current sensor.
Specifically: the calculation formula of the DC magnetic bias tolerance value I p of the transformer is as follows:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value k 0/3 by pressurizing the transformer; i 0 denotes a rated no-load current value of the transformer.
The rated no-load current value I 0 of the transformer is obtained by inquiring the nameplate parameters of the transformer.
And 4, performing return-to-zero of the magnetic flux of the transformer core, namely repeating the step 2.
The working principle is as follows: the method for checking the DC magnetic bias tolerance capability of the transformer based on the prior art adopts a power frequency injection DC mode to test, two transformer tested products with consistent capacity and other performances are needed, the capacity of a test power supply is far greater than the no-load capacity of the transformer, the requirement on test conditions is high, and the method has no feasibility in field checking. The invention designs a method for checking the DC magnetic bias tolerance of a transformer, which is easy to implement on site and can detect the DC magnetic bias tolerance of the transformer on site through controllable wave voltage source injection and current detection. The invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site, ensures that the requirement of the magnetic bias tolerance capacity of the transformer excitation is reliably executed, and improves the operation reliability of the transformer.
Compared with the prior art, the invention has the beneficial effects that:
(1) The method for checking the DC magnetic bias tolerance capability of the transformer by the existing laboratory DC superposition power frequency technology has huge equipment, and the method provided by the invention simplifies test equipment.
(2) At present, the power grid puts a DC magnetic bias tolerance requirement on the transformer, no method is used for executing the test of the capability requirement on site, and the method can change the current situation.
(3) By using the method of the invention, before and after the detection of the DC bias current tolerance value of the transformer, the magnetic flux of the transformer core is required to be zeroed, so that the magnetizing inrush current of the transformer during operation can be reduced.
Example 2
As shown in fig. 3, the difference between the present embodiment and embodiment 1 is that the present embodiment provides a system for checking dc bias withstand capability of a transformer, which supports the method for checking dc bias withstand capability of a transformer according to embodiment 1, and the system includes a transformer, a controllable wave power supply, a current sensor, and a power supply control unit; one side of the transformer is opened, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
The power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects the current i, and the real-time excitation curve of the transformer core is formed through real-time processing of collected data; pressurizing the transformer to enable the real-time slope k of the transformer core curve to reach a preset value, and stopping pressurizing; and calculating the DC magnetic bias tolerance value of the transformer at the moment, and detecting the DC magnetic bias tolerance capability of the transformer.
In the embodiment, the magnetic flux of the iron core of the transformer needs to be zeroed before and after the DC magnetic bias tolerance capability detection of the transformer is carried out, so that the excitation surge current of the transformer during operation can be reduced; the execution process for zeroing the magnetic flux of the transformer core is as follows:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A, enabling the magnetic flux psi m of the transformer core to reach a positive magnetic saturation state;
Controlling a controllable wave power supply to output-U voltage, and enabling the magnetic flux psi m of the transformer core to reach a negative magnetic saturation state when the current detected by the current sensor reaches-5A;
Recording the time 2T when the magnetic flux psi m of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
And starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
The process of applying + -U with a gradual decay of 50% starting at 1.5T time includes four phases, as follows:
the first stage: applying positive voltage 1.5T from the negative magnetic saturation state of the transformer, wherein the magnetic flux point of the transformer reaches +0.5ψ m;
the second stage: applying a negative voltage of 0.75T from transformer flux +0.5 ψ m, transformer flux point reaching-0.25 ψ m;
third stage: applying a positive voltage of 0.375T from a transformer flux of-0.25 ψ m, the transformer flux point reaching +0.125 ψm;
Fourth stage: the negative voltage of 0.1875T is applied from the transformer magnetic flux +0.125 psi m, the transformer magnetic flux point reaches-0.0625 psi m, and the transformer magnetic return to zero is finished.
The square wave controllable source voltage application process is shown in fig. 4, and the transformer core magnetic flux change is shown in fig. 5.
In this embodiment, the power control unit controls the controllable wave source to output +u voltage, the current sensor detects the current i, and the real-time excitation curve of the transformer core is formed through real-time processing of the collected data, as shown in fig. 6; the initial point slope of the excitation curve of the transformer core is k 0, the transformer is pressurized, the real-time slope k of the transformer core curve reaches a preset value k 0/3, when k is k 0/3, the current value I is recorded, the pressurization is stopped, and the pressurization process is shown in fig. 7; and calculating the DC magnetic bias tolerance value of the transformer at the moment, and detecting the DC magnetic bias tolerance capability of the transformer.
The calculation formula of the DC magnetic bias tolerance value I p of the transformer is as follows:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value by pressurizing the transformer; i 0 represents a rated no-load current value of the transformer, and the rated no-load current value of the transformer is obtained by inquiring a nameplate parameter of the transformer; the preset value k 0/3,k0 represents the initial value of the slope of the real-time excitation curve of the transformer core.
The on-site test system for checking the DC magnetic bias tolerance of the transformer is easy to implement on site, and test equipment is simplified; and the DC magnetic bias tolerance of the transformer is detected on site through controllable wave voltage source injection and current detection. The invention solves the problem of the method for testing the DC magnetic bias tolerance capacity of the transformer on site, ensures that the requirement of the magnetic bias tolerance capacity of the transformer excitation is reliably executed, and improves the operation reliability of the transformer. The invention solves the problem that the required equipment is huge in the existing method for checking the DC magnetic bias tolerance capability of the transformer by using the DC superposition power frequency technology in the laboratory. In addition, the system of the invention needs to return to zero the magnetic flux of the transformer iron core before and after the detection of the DC magnetic bias tolerance current value of the transformer, thereby reducing the excitation surge current of the transformer during operation.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (7)
1. A method for checking DC magnetic bias tolerance of a transformer on site is characterized by comprising the following steps:
Step 1, carrying out direct current magnetic bias tolerance test wiring: one side of the transformer is open, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
step 2, initializing the return of the magnetic flux of the transformer core to zero;
Step 3, detecting the DC magnetic bias tolerance of the transformer: the power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects current, and the current is processed in real time through collected data to form a real-time excitation curve of the transformer core; pressurizing the transformer to enable the real-time slope of the transformer core curve to reach a preset value, and stopping pressurizing; calculating the DC magnetic bias tolerance value of the transformer at the moment;
the calculation formula of the real-time slope k of the transformer core curve in the step 3 is as follows:
In the method, in the process of the invention, The flux linkage is obtained by calculating the integral of the output voltage +U of the controllable wave power supply to the time t; k represents the real-time slope of the transformer core curve, and is determined by flux linkage/>Calculating the derivative of the current i detected by the current sensor;
the calculation formula of the dc bias tolerance value I p of the transformer in step 3 is as follows:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value by pressurizing the transformer; i 0 denotes a rated no-load current value of the transformer.
2. The method for checking the dc bias magnetic endurance of the transformer according to claim 1, wherein the initialization of the transformer core flux return to zero in the step2 specifically comprises:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A or 10A, enabling the magnetic flux of the transformer iron core to reach a positive magnetic saturation state;
Controlling a controllable wave power supply to output-U voltage, and enabling the magnetic flux of the transformer iron core to reach a negative magnetic saturation state when the current detected by the current sensor reaches-5A or-10A;
recording the time 2T when the magnetic flux of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
and starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
3. The method for checking the DC magnetic bias tolerance of the transformer according to claim 1, wherein the rated no-load current value I 0 of the transformer is obtained by inquiring the nameplate parameters of the transformer.
4. The method for checking the dc bias withstand capability of a transformer according to claim 1, wherein the preset value in the step 3 is k 0/3, where k 0 represents an initial value of a slope of a real-time excitation curve of a transformer core.
5. The method for checking the DC magnetic bias tolerance of the transformer according to claim 1, wherein the method further comprises a step4 after the step 3, and the magnetic flux of the transformer core is zeroed.
6. A field test system for checking the dc bias withstand capability of a transformer, characterized in that the system supports a field test method for checking the dc bias withstand capability of a transformer according to any one of claims 1 to 5, the system comprising a transformer, a controllable wave power supply, a current sensor and a power supply control unit; one side of the transformer is opened, the other side of the transformer is sequentially connected with a controllable wave power supply and a current sensor in series, a signal of the current sensor is transmitted to a power supply control unit, and the power supply control unit controls the output of the controllable wave power supply;
The power supply control unit controls the controllable wave source to output +U voltage, the current sensor detects the current i, and the real-time excitation curve of the transformer core is formed through real-time processing of collected data; pressurizing the transformer to enable the real-time slope k of the transformer core curve to reach a preset value, and stopping pressurizing; calculating the DC magnetic bias tolerance value of the transformer at the moment, and detecting the DC magnetic bias tolerance capacity of the transformer;
The calculation formula of the real-time slope k of the transformer core curve is as follows:
In the method, in the process of the invention, The flux linkage is obtained by calculating the integral of the output voltage +U of the controllable wave power supply to the time t; k represents the real-time slope of the transformer core curve, and is determined by flux linkage/>Calculating the derivative of the current i detected by the current sensor;
the calculation formula of the DC magnetic bias tolerance value I p of the transformer is as follows:
Wherein I p represents a DC bias tolerance value of the transformer; i represents the current value measured by the current sensor when the real-time slope k of the transformer core curve reaches a preset value by pressurizing the transformer; i 0 represents a rated no-load current value of the transformer, and the rated no-load current value of the transformer is obtained by inquiring a nameplate parameter of the transformer; the preset value k 0/3,k0 represents the initial value of the slope of the real-time excitation curve of the transformer core.
7. The on-site test system for checking the DC magnetic bias tolerance of the transformer according to claim 6, wherein the magnetic flux of the transformer core is zeroed before and after the DC magnetic bias tolerance of the transformer is detected; the execution process for zeroing the magnetic flux of the transformer core is as follows:
Controlling the controllable wave power supply to output +U voltage, and when the current detected by the current sensor reaches 5A or 10A, enabling the magnetic flux of the transformer iron core to reach a positive magnetic saturation state;
Controlling a controllable wave power supply to output-U voltage, and enabling the magnetic flux of the transformer iron core to reach a negative magnetic saturation state when the current detected by the current sensor reaches-5A or-10A;
recording the time 2T when the magnetic flux of the transformer reaches the positive magnetic saturation state to the negative magnetic saturation state;
and starting to gradually attenuate by 50% at 1.5T time to apply + -U, thereby realizing the return-to-zero of the magnetic flux of the transformer core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111306186.XA CN114019286B (en) | 2021-11-05 | 2021-11-05 | Transformer direct-current magnetic bias tolerance capability checking field test method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111306186.XA CN114019286B (en) | 2021-11-05 | 2021-11-05 | Transformer direct-current magnetic bias tolerance capability checking field test method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114019286A CN114019286A (en) | 2022-02-08 |
| CN114019286B true CN114019286B (en) | 2024-04-26 |
Family
ID=80061404
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111306186.XA Active CN114019286B (en) | 2021-11-05 | 2021-11-05 | Transformer direct-current magnetic bias tolerance capability checking field test method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114019286B (en) |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0277663A (en) * | 1988-09-14 | 1990-03-16 | Toshiba Corp | Method for detecting dc magnetic deflection of core of transformer |
| CN1710437A (en) * | 2005-04-30 | 2005-12-21 | 国电南京自动化股份有限公司 | Method for judging internal fault of transformer using excitation property |
| CN102608552A (en) * | 2012-04-14 | 2012-07-25 | 河北工业大学 | Acquiring method of DC (direct-current) bias magnet ratio total losses curve of transformer core material |
| CN202522634U (en) * | 2011-09-28 | 2012-11-07 | 特变电工股份有限公司 | Device for detecting capacity for withstanding direct-current magnetic biasing of transformer |
| CN103033695A (en) * | 2011-09-28 | 2013-04-10 | 特变电工股份有限公司 | Detection method of transformer direct current bias magnetic tolerance ability |
| CN103176069A (en) * | 2011-12-23 | 2013-06-26 | 特变电工沈阳变压器集团有限公司 | Test method for applying DC (Direct Current) magnetic bias current of transformer |
| JP2014150598A (en) * | 2013-01-31 | 2014-08-21 | Hitachi Ltd | Electric power conversion system and determination method for bias magnetism of transformer |
| CN104330662A (en) * | 2014-10-23 | 2015-02-04 | 中国南方电网有限责任公司电网技术研究中心 | Testing device and testing method for direct-current magnetic bias of converter transformer |
| CN104849587A (en) * | 2015-04-30 | 2015-08-19 | 国网四川省电力公司电力科学研究院 | Method for analyzing excitation characteristic change of transformer under influence of direct-current magnetic bias |
| CN106019050A (en) * | 2016-05-24 | 2016-10-12 | 山东达驰电气有限公司 | Test circuit and method under DC bias effect of transformers |
| CN106655097A (en) * | 2017-01-09 | 2017-05-10 | 湖南大学 | Magnetizing inrush current identification method for power transformer |
| JP2017194290A (en) * | 2016-04-18 | 2017-10-26 | 新日鐵住金株式会社 | Dc-biased magnetization detection method for transformer core, and dc-biased magnetization detection system for transformer core |
| CN108241099A (en) * | 2016-12-27 | 2018-07-03 | 大唐观音岩水电开发有限公司 | A kind of transformer DC magnetic bias status assessment and diagnostic method |
| CN111965569A (en) * | 2020-07-06 | 2020-11-20 | 南方电网科学研究院有限责任公司 | DC magnetic bias level measurement method, device and system for on-line operation transformer |
-
2021
- 2021-11-05 CN CN202111306186.XA patent/CN114019286B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0277663A (en) * | 1988-09-14 | 1990-03-16 | Toshiba Corp | Method for detecting dc magnetic deflection of core of transformer |
| CN1710437A (en) * | 2005-04-30 | 2005-12-21 | 国电南京自动化股份有限公司 | Method for judging internal fault of transformer using excitation property |
| CN202522634U (en) * | 2011-09-28 | 2012-11-07 | 特变电工股份有限公司 | Device for detecting capacity for withstanding direct-current magnetic biasing of transformer |
| CN103033695A (en) * | 2011-09-28 | 2013-04-10 | 特变电工股份有限公司 | Detection method of transformer direct current bias magnetic tolerance ability |
| CN103176069A (en) * | 2011-12-23 | 2013-06-26 | 特变电工沈阳变压器集团有限公司 | Test method for applying DC (Direct Current) magnetic bias current of transformer |
| CN102608552A (en) * | 2012-04-14 | 2012-07-25 | 河北工业大学 | Acquiring method of DC (direct-current) bias magnet ratio total losses curve of transformer core material |
| JP2014150598A (en) * | 2013-01-31 | 2014-08-21 | Hitachi Ltd | Electric power conversion system and determination method for bias magnetism of transformer |
| CN104330662A (en) * | 2014-10-23 | 2015-02-04 | 中国南方电网有限责任公司电网技术研究中心 | Testing device and testing method for direct-current magnetic bias of converter transformer |
| CN104849587A (en) * | 2015-04-30 | 2015-08-19 | 国网四川省电力公司电力科学研究院 | Method for analyzing excitation characteristic change of transformer under influence of direct-current magnetic bias |
| JP2017194290A (en) * | 2016-04-18 | 2017-10-26 | 新日鐵住金株式会社 | Dc-biased magnetization detection method for transformer core, and dc-biased magnetization detection system for transformer core |
| CN106019050A (en) * | 2016-05-24 | 2016-10-12 | 山东达驰电气有限公司 | Test circuit and method under DC bias effect of transformers |
| CN108241099A (en) * | 2016-12-27 | 2018-07-03 | 大唐观音岩水电开发有限公司 | A kind of transformer DC magnetic bias status assessment and diagnostic method |
| CN106655097A (en) * | 2017-01-09 | 2017-05-10 | 湖南大学 | Magnetizing inrush current identification method for power transformer |
| CN111965569A (en) * | 2020-07-06 | 2020-11-20 | 南方电网科学研究院有限责任公司 | DC magnetic bias level measurement method, device and system for on-line operation transformer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114019286A (en) | 2022-02-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Sen et al. | Stator interturn fault detection in permanent-magnet machines using PWM ripple current measurement | |
| CN102073012B (en) | Method and system for obtaining parameters of synchronous generator | |
| CN104833928A (en) | Large-scale power transformer residual magnetism detection method | |
| CN101650390B (en) | Method of measuring inductance parameters of stator of surface AC permanent magnet synchronous motor on line | |
| CN102565540A (en) | Method and arrangement for determining inductances of synchronous reluctance machine | |
| CN102668361B (en) | Motor control apparatus and magnetic-pole position detection method therefor | |
| Seok et al. | Optimal flux selection of an induction machine for maximum torque operation in flux-weakening region | |
| CN114019286B (en) | Transformer direct-current magnetic bias tolerance capability checking field test method and system | |
| CN102749595B (en) | Method for measuring residual magnetic induction density of iron core of transformer | |
| CN102103194A (en) | Device and method for measuring two-dimensional magnetic properties of electric steel sheet with adjustable magnetic circuit | |
| CN108536116B (en) | Testing method and system of speed regulating system | |
| Vo et al. | Novel adaptive controller for effective magnetic measurement under arbitrary magnetization | |
| CN108535558B (en) | Method and system for testing power stabilizer | |
| Ibrahim et al. | Novel equipment for the measurement of core losses in laminations for advanced machines | |
| CN105807143A (en) | Method for precisely measuring stray loss of structural components of transformers | |
| CN111965569B (en) | DC magnetic bias level measurement method, device and system for online operation transformer | |
| Thiemann et al. | Direct Flux Control (DFC): A new sensorless control method for PMSM | |
| CN108051698A (en) | Coil turn-to-turn insulation failure detection method, apparatus and system | |
| CN112345966A (en) | Method and device for detecting direct current leakage through residual current transformer | |
| CN108599638A (en) | A kind of discrimination method of permanent-magnetic synchronous motor stator magnetic linkage | |
| US20180259565A1 (en) | Energizing coil wound on magnetic core and oscillatory testing of transformer | |
| Fagan et al. | Iterative methods for waveform control in magnetic measurement systems | |
| CN111929626B (en) | Transformer residual magnetism estimation device and method | |
| CN113252719B (en) | Method and device for testing gas-water permeability curve of reservoir | |
| CN219122388U (en) | Test device for weakening residual magnetism of magnetic core and test platform for weakening residual magnetism of magnetic core |
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 |