CN219737744U - Calibrating device for DC resistance tester of transformer - Google Patents
Calibrating device for DC resistance tester of transformer Download PDFInfo
- Publication number
- CN219737744U CN219737744U CN202320636853.9U CN202320636853U CN219737744U CN 219737744 U CN219737744 U CN 219737744U CN 202320636853 U CN202320636853 U CN 202320636853U CN 219737744 U CN219737744 U CN 219737744U
- Authority
- CN
- China
- Prior art keywords
- voltage
- circuit
- resistance tester
- resistor
- full
- 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
- 238000005070 sampling Methods 0.000 claims abstract description 39
- 239000003990 capacitor Substances 0.000 claims description 27
- 238000010586 diagram Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model provides a calibration device of a transformer direct current resistance tester, which comprises a main control chip, wherein the main control chip generates a first PWM signal, a second PWM signal and a third PWM signal for respectively controlling output values of a first voltage lifting circuit, a second voltage lifting circuit and a third voltage lifting circuit; the three voltage acquisition modules convert the output currents of the A phase, the B phase and the C phase of the transformer direct current resistance tester into voltage signals U a 、U b And U c Voltage signal U a 、U b And U c One path is respectively sent to the main control chip, and the other path is respectively used as the control voltage input of the three voltage lifting circuits. The device not only can realize transformationThe device has three current sampling circuits, so that the requirement of calibration of the three-loop transformer direct current resistance tester can be completely met, and the working efficiency is greatly improved.
Description
Technical Field
The utility model relates to the technical field of tester calibration devices, in particular to a transformer direct current resistance tester calibration device.
Background
The transformer DC resistance tester is used for testing the DC resistance between windings of single-phase and three-phase transformers, and is commonly used in the market, and comprises a single loop (used for testing the DC resistance of the single-phase transformer) and two loops (used for testing the DC resistance of the three-phase transformer).
The current real standard resistance method adopted by the tracing method for the resistance value of the transformer direct current resistance tester only can calibrate the transformer direct current resistance tester by using fixed resistance points because the real standard resistance is a fixed resistance value, but cannot calibrate the resistance value among the fixed resistance values, so that the aim of continuously and adjustably calibrating the resistance value of the transformer direct current resistance tester cannot be achieved. Meanwhile, the adoption of the real standard resistor is only suitable for calibrating the single-loop type transformer direct current resistance tester, and the three-loop type transformer direct current resistance tester needs to trace the source of each phase of direct current resistance value according to the phase A, the phase B and the phase C respectively, and the three-loop type transformer direct current resistance tester needs to be rewiring when the three-loop type transformer direct current resistance tester changes phase each time, so that the operation is complex and troublesome, the automation degree is low, and the overall working efficiency are low.
Disclosure of Invention
The utility model aims to solve the technical problem of providing a calibration device for a DC resistance tester of a transformer, which can be used for conveniently calibrating the DC resistance tester of a three-loop transformer.
The utility model is realized in the following way: the utility model provides a calibration device of a transformer direct-current resistance tester, which comprises a main control chip, a first voltage acquisition module, a second voltage acquisition module, a third voltage acquisition module, a first voltage lifting circuit, a second voltage lifting circuit and a third voltage lifting circuit, wherein the first voltage acquisition module, the second voltage acquisition module, the third voltage acquisition module, the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit are respectively connected with the main control chip;
the main control chip generates a first PWM signal, a second PWM signal and a third PWM signal, and the first PWM signal, the second PWM signal and the third PWM signal respectively control the output values of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit;
the first voltage acquisition module acquires output current I of A phase of a transformer direct current resistance tester A Converted into a voltage signal U a The second voltage acquisition module acquires the output current I of the B phase of the transformer direct current resistance tester B Converted into a voltage signal U b The third voltage acquisition module acquires output current I of C phase of the transformer direct current resistance tester C Converted into a voltage signal U c The voltage signal U a 、U b And U c Is divided into two paths, the voltage signal U a 、U b And U c One path is respectively sent to the main control chip, and the other path is respectively used as the control voltage input of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit.
Further, the first voltage acquisition module comprises a first standard load resistor and a first current sampling circuit, wherein the first standard load resistor is connected with the first current sampling circuit, and the first current sampling circuit is connected with the main control chip.
Further, the second voltage acquisition module comprises a second standard load resistor and a second current sampling circuit, wherein the second standard load resistor is connected with the second current sampling circuit, and the second current sampling circuit is connected with the main control chip.
Further, the third voltage acquisition module comprises a third standard load resistor and a third current sampling circuit, wherein the third standard load resistor is connected with the third current sampling circuit, and the third current sampling circuit is connected with the main control chip.
Further, the accuracy level of the first, second and third standard load resistors is greater than or equal to 0.01 level.
Further, the first voltage step-up/step-down circuit is configured to output a voltage signal U A The first voltage lifting circuit comprises an inductor L1, a diode D1, a full-control device Q1, a capacitor C1 and a resistor R1;
the base electrode of the full-control device Q1 is connected with a first PWM signal, and the collector electrode of the full-control device Q1 is connected with a voltage signal U a The emitter of the full-control device Q1 is connected with the inductor L1 and the cathode of the diode D1 respectively, one end of the capacitor C1 and one end of the resistor R1 are connected with the anode of the diode D1 respectively, and the other end of the capacitor C1 and the other end of the resistor R1 are connected with the inductor L1 respectively.
Further, the second voltage step-up/step-down circuit is configured to output a voltage signal U B The second voltage lifting circuit comprises an inductor L2, a diode D2, a full-control device Q2, a capacitor C2 and a resistor R2;
the base electrode of the full-control device Q2 is connected with a second PWM signal, and the collector electrode of the full-control device Q2 is connected with a voltage signal U b The emitter of the full-control device Q2 is connected with the cathodes of the inductor L2 and the diode D2 respectively, one ends of the capacitor C2 and the resistor R2 are connected with the anode of the diode D2 respectively, and the other ends of the capacitor C2 and the resistor R2 are connected with the inductor L2 respectively.
Further, the third voltage step-up/step-down circuit is configured to output a voltage signal U C The third voltage lifting circuit comprises an inductor L3, a diode D3, a full-control device Q3, a capacitor C3 and a resistor R3;
the base electrode of the full-control device Q3 is connected with a third PWM signal, and the collector electrode of the full-control device Q3 is connected with a voltage signal U b The emitter of the full-control device Q3 is connected with the inductor L3 and the cathode of the diode D3 respectively, one end of the capacitor C3 and one end of the resistor R3 are connected with the anode of the diode D3 respectively, and the other end of the capacitor C3 and the other end of the resistor R3 are connected with the inductor L3 respectively.
The utility model has the advantages that: according to the device, the three voltage acquisition modules are used for acquiring voltages loaded on three standard load resistors, on the other hand, the main control chip multiplies the sampled current value by a resistance value which is written into the main control chip in advance and needs to be calibrated to obtain a voltage value, the voltage value is compared with the voltage acquired by the main control chip through the current sampling circuit to obtain a proportional coefficient value, and the main control chip generates PWM signals according to the proportional coefficient value to control the output of the three voltage lifting circuits to the voltage input end of the transformer direct current resistance tester so as to calibrate the transformer direct current resistance.
The three-way voltage lifting circuit designed by the device can control the voltage U A 、U B And U C The value of (2) is U a 、U b And U c The value is adjusted up and down, but not the boosting or the reducing when the value is first, and the method is more convenient and flexible.
By adopting the device, the continuous adjustable calibration of the DC resistance value of the transformer can be realized, and meanwhile, the device is provided with three current sampling circuits, so that the calibration requirement of the DC resistance tester of the three-loop transformer can be completely met, and the working efficiency is greatly improved.
Drawings
The utility model will be further described with reference to examples of embodiments with reference to the accompanying drawings.
FIG. 1 is a schematic diagram of the structure of the present utility model;
FIG. 2 is a schematic diagram of a first voltage step-up/step-down circuit according to the present utility model;
FIG. 3 is a schematic diagram of a second voltage step-up/step-down circuit according to the present utility model;
FIG. 4 is a schematic diagram of a third voltage step-up/step-down circuit according to the present utility model;
FIG. 5 is a U of the present utility model A 、U B And U C Waveform diagram during boosting;
FIG. 6 is a U of the present utility model A 、U B And U C Schematic diagram of waveform at the time of depressurization.
Detailed Description
Referring to fig. 1 to 6, the present utility model provides a calibration device for a dc resistance tester of a transformer, which includes a main control chip, a first voltage acquisition module, a second voltage acquisition module, a third voltage acquisition module, a first PWM signal, a first voltage raising/lowering circuit, a second PWM signal, a second voltage raising/lowering circuit, a third PWM signal, and a third voltage raising/lowering circuit, which are respectively connected with the main control chip;
the main control chip generates a first PWM signal, a second PWM signal and a third PWM signal, and the first PWM signal, the second PWM signal and the third PWM signal respectively control the output values of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit;
the first voltage acquisition module converts the output current of the A phase of the transformer direct current resistance tester into a voltage signal U a The second voltage acquisition module converts the output current of the B phase of the transformer direct current resistance tester into a voltage signal U b The third voltage acquisition module converts the output current of the C phase of the transformer direct current resistance tester into a voltage signal U c The voltage signal U a 、U b And U c Is divided into two paths, the voltage signal U a 、U b And U c One path is respectively sent to the main control chip, and the other path is respectively used as the control voltage input of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit.
Specifically, the first voltage acquisition module comprises a first standard load resistor and a first current sampling circuit, wherein the first standard load resistor is connected with the first current sampling circuit, and the first current sampling circuit is connected with the main control chip.
Specifically, the second voltage acquisition module comprises a second standard load resistor and a second current sampling circuit, wherein the second standard load resistor is connected with the second current sampling circuit, and the second current sampling circuit is connected with the main control chip.
Specifically, the third voltage acquisition module comprises a third standard load resistor and a third current sampling circuit, wherein the third standard load resistor is connected with the third current sampling circuit, and the third current sampling circuit is connected with the main control chip.
Specifically, the accuracy level of the first, second and third standard load resistors is higher than or equal to 0.01 level. The resistance values of the first standard load resistor, the second standard load resistor and the third standard load resistor are equal.
Specifically, the first voltage step-up/step-down circuit is configured to output a voltage signal U A The first voltage lifting circuit comprises an inductor L1, a diode D1, a full-control device Q1, a capacitor C1 and a resistor R1;
the base electrode of the full-control device Q1 is connected with a first PWM signal, and the collector electrode of the full-control device Q1 is connected with a voltage signal U a The emitter of the full-control device Q1 is connected with the inductor L1 and the cathode of the diode D1 respectively, one end of the capacitor C1 and one end of the resistor R1 are connected with the anode of the diode D1 respectively, and the other end of the capacitor C1 and the other end of the resistor R1 are connected with the inductor L1 respectively.
Specifically, the second voltage step-up/step-down circuit is configured to output a voltage signal U B The second voltage lifting circuit comprises an inductor L2, a diode D2, a full-control device Q2, a capacitor C2 and a resistor R2;
the base electrode of the full-control device Q2 is connected with a second PWM signal, and the collector electrode of the full-control device Q2 is connected with a voltage signal U b The emitter of the full-control device Q2 is connected with the cathodes of the inductor L2 and the diode D2 respectively, one ends of the capacitor C2 and the resistor R2 are connected with the anode of the diode D2 respectively, and the other ends of the capacitor C2 and the resistor R2 are connected with the inductor L2 respectively.
Specifically, the third voltage step-up/step-down circuit is configured to output a voltage signal U C The third voltage lifting circuit comprises an inductor L3, a diode D3, a full-control device Q3, a capacitor C3 and a resistor R3;
the base electrode of the full-control device Q3 is connected with a third PWM signal, and the collector electrode of the full-control device Q3 is connected with a voltage signal U b The emitter of the full-control device Q3 is connected with the inductor L3 and the cathode of the diode D3 respectively, one end of the capacitor C3 and one end of the resistor R3 are connected with the anode of the diode D3 respectively, and the other end of the capacitor C3 and the other end of the resistor R3 are connected with the inductor L3 respectively.
One specific application of the utility model is:
the DC resistance tester of the transformer controls according to the current range of the testerThe current output of the phase A, the phase B and the phase C is loaded on a first standard load resistor, a second standard load resistor and a third standard load resistor, and the loaded currents are respectively I a 、I b And I c . I output by the first current sampling circuit, the second current sampling circuit and the third current sampling circuit to the transformer direct current resistance tester respectively a 、I b And I c The current is converted into current-voltage to obtain three voltage signals U a 、U b And U c The three voltage signals are divided into two paths, one path is sent to the main control chip for analysis and calculation, and the other path is used as the control voltage input of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit.
Wherein the calculation process is that the main control chip multiplies the sampled current value with the resistance value which is written in the main control chip in advance and needs to be calibrated to obtain voltage values (the voltage values are U respectively A 、U B And U C ) And comparing the voltage value with the voltage acquired by the main control chip through the current sampling circuit to obtain a proportional coefficient value. Namely:
let the current DC resistance tester of the transformer to be calibrated have the resistance value R 0 The resistance values of the first standard load resistor, the second standard load resistor and the third standard load resistor are all R Label (C) The voltage input ends of the A phase, the B phase and the C phase of the transformer direct current resistance tester are respectively (can be understood as the voltage to be output by the device) according to ohm law theory:
U A ＝I a R 0
U B ＝I b R 0
U C ＝I c R 0 (1)
u that main control chip gathered through three current sampling circuit a 、U b 、U c Three-way voltage signal and U A 、U B 、U C The proportional relationships of (a) are as follows:
in the figure, the voltage U output by a first voltage lifting circuit, a second voltage lifting circuit and a third voltage lifting circuit A 、U B 、U C And U a 、U b 、U c The relation of (2) is:
because the transformer direct current resistance tester is provided with a plurality of current range blocks, the three voltage lifting circuits designed by the device can control the voltage U A 、U B 、U C Value at U a 、U b 、U c The value is adjustable up and down, but not the boost or the buck which is the same, and the method is more convenient and flexible. If the voltage U output by the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit is required A 、U B And U C Is greater than U a 、U b And U c By changing the value of T on And T off Make T on Time length is longer than T off As shown in fig. 5. If the voltage U output by the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit is required A 、U B And U C Is smaller than U a 、U b And U c By changing the value of T on And T off Make T on Duration is less than T off As shown in fig. 6.
The main control chip only needs to control the first PWM signal, the second PWM signal and the third PWM signal to generate three paths of duty ratio signal values of k respectively according to the formula (3) A 、k B 、k C Control U can be realized A 、U B 、U C Is provided. And U is set A 、U B 、U C The output of the voltage measuring circuit is sent to a voltage sampling end of the transformer direct current resistance tester for sampling, and then the resistance values measured by the transformer direct current resistance tester can be obtained according to ohm's law and are respectively as follows:
as can be derived from the formula (4), the resistance value simulated by the sampling method is only equal to the PWM signal duty ratio value and the resistance R generated by the main control chip Label (C) Related to the following. The first standard load resistor, the second standard load resistor and the third standard load resistor are selected to be more than 0.01 level, so that the accuracy level of the calibrating device can be greatly improved.
The device can realize the continuous adjustable calibration of the DC resistance value of the transformer, and simultaneously, the device is provided with three current sampling circuits, so that the calibration requirement of the DC resistance tester of the three-loop transformer can be completely met, and the working efficiency is greatly improved. The utility model has novel and unique conception, specific and practical realization scheme, fewer adopted components, simple whole circuit structure and better use value.
While specific embodiments of the utility model have been described above, it will be appreciated by those skilled in the art that the specific embodiments described are illustrative only and not intended to limit the scope of the utility model, and that equivalent modifications and variations of the utility model in light of the spirit of the utility model will be covered by the claims of the present utility model.
Claims (8)
1. The utility model provides a transformer direct current resistance tester calibrating device which characterized in that: the device comprises a main control chip, a first voltage acquisition module, a second voltage acquisition module, a third voltage acquisition module, a first voltage lifting circuit, a second voltage lifting circuit and a third voltage lifting circuit which are respectively connected with the main control chip;
the main control chip generates a first PWM signal, a second PWM signal and a third PWM signal, and the first PWM signal, the second PWM signal and the third PWM signal respectively control the output values of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit;
the first voltage acquisition module converts the output current of the A phase of the transformer direct current resistance tester into a voltage signal U a The second voltage acquisition module converts the output current of the B phase of the transformer direct current resistance tester into a voltage signal U b The third voltage acquisition module converts the output current of the C phase of the transformer direct current resistance tester into a voltage signal U c The voltage signal U a 、U b And U c Is divided into two paths, the voltage signal U a 、U b And U c One path is respectively sent to the main control chip, and the other path is respectively used as the control voltage input of the first voltage lifting circuit, the second voltage lifting circuit and the third voltage lifting circuit.
2. The calibration device for a transformer direct current resistance tester according to claim 1, wherein: the first voltage acquisition module comprises a first standard load resistor and a first current sampling circuit, wherein the first standard load resistor is connected with the first current sampling circuit, and the first current sampling circuit is connected with the main control chip.
3. The calibration device for a transformer direct current resistance tester according to claim 2, wherein: the second voltage acquisition module comprises a second standard load resistor and a second current sampling circuit, wherein the second standard load resistor is connected with the second current sampling circuit, and the second current sampling circuit is connected with the main control chip.
4. A transformer direct current resistance tester calibration apparatus as recited in claim 3, wherein: the third voltage acquisition module comprises a third standard load resistor and a third current sampling circuit, wherein the third standard load resistor is connected with the third current sampling circuit, and the third current sampling circuit is connected with the main control chip.
5. The calibration device for a transformer direct current resistance tester according to claim 4, wherein: the first, second and third standard load resistors have an accuracy level greater than or equal to 0.01.
6. The calibration device for a transformer direct current resistance tester according to claim 1, wherein: the first voltage step-up/step-down circuit is used for outputting a voltage signal U A The first voltage lifting circuit comprises an inductor L1, a diode D1, a full-control device Q1, a capacitor C1 and a resistor R1;
the base electrode of the full-control device Q1 is connected with a first PWM signal, and the collector electrode of the full-control device Q1 is connected with a voltage signal U a The emitter of the full-control device Q1 is connected with the inductor L1 and the cathode of the diode D1 respectively, one end of the capacitor C1 and one end of the resistor R1 are connected with the anode of the diode D1 respectively, and the other end of the capacitor C1 and the other end of the resistor R1 are connected with the inductor L1 respectively.
7. The calibration device for a transformer direct current resistance tester according to claim 1, wherein: the second voltage step-up/step-down circuit is used for outputting a voltage signal U B The second voltage lifting circuit comprises an inductor L2, a diode D2, a full-control device Q2, a capacitor C2 and a resistor R2;
the base electrode of the full-control device Q2 is connected with a second PWM signal, and the collector electrode of the full-control device Q2 is connected with a voltage signal U b The emitter of the full-control device Q2 is connected with the cathodes of the inductor L2 and the diode D2 respectively, one ends of the capacitor C2 and the resistor R2 are connected with the anode of the diode D2 respectively, and the other ends of the capacitor C2 and the resistor R2 are connected with the inductor L2 respectively.
8. The calibration device for a transformer direct current resistance tester according to claim 1, wherein: the third voltage step-up/step-down circuit is used for outputting a voltage signal U C The third voltage lifting circuit comprises an inductor L3, a diode D3, a full-control device Q3, a capacitor C3 and a resistor R3;
the base electrode of the full-control device Q3 is connected with a third PWM signal, and the collector electrode of the full-control device Q3 is connected with a voltage signal U b The emitter of the full-control device Q3 is connected with the inductor L3 and the cathode of the diode D3 respectively, one end of the capacitor C3 and one end of the resistor R3 are connected with the anode of the diode D3 respectively, and the other end of the capacitor C3 and the other end of the resistor R3 are connected with the inductor L3 respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320636853.9U CN219737744U (en) | 2023-03-28 | 2023-03-28 | Calibrating device for DC resistance tester of transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320636853.9U CN219737744U (en) | 2023-03-28 | 2023-03-28 | Calibrating device for DC resistance tester of transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219737744U true CN219737744U (en) | 2023-09-22 |
Family
ID=88031660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320636853.9U Active CN219737744U (en) | 2023-03-28 | 2023-03-28 | Calibrating device for DC resistance tester of transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219737744U (en) |
-
2023
- 2023-03-28 CN CN202320636853.9U patent/CN219737744U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102801300B (en) | Primary-side feedback controlled switching power line loss compensating system and method | |
| CN107345996B (en) | Field effect transistor test circuit and test method | |
| TWI405066B (en) | Power factor correction circuit and method therefor | |
| EP0636889A1 (en) | Current estimating circuit for switch mode power supply | |
| CN203479877U (en) | Device and system for sensing and regulating inductor current in inductor | |
| CN207424076U (en) | Current detection circuit | |
| CN106535391B (en) | Peak current absorbing circuit and its control method and light emitting diode drive device | |
| CN106714367B (en) | Constant-current circuit and its constant-current controller | |
| CN218240297U (en) | Dynamic performance testing device for wide-bandgap power semiconductor device | |
| CN111064401A (en) | High-precision voltage-regulating constant-current source system suitable for strong inductive load | |
| CN107402324A (en) | Power supply sample circuit, method and its low-voltage circuit breaker based on single electric current transformer | |
| CN219737744U (en) | Calibrating device for DC resistance tester of transformer | |
| CN109343433B (en) | High-precision high-resolution programmable power supply circuit | |
| CN109327141A (en) | A kind of wide-range voltage and High-current output method and power-supply system | |
| CN108964464B (en) | Circuit and method for nondestructive testing of load current at output side of switching power supply | |
| CN116203373B (en) | Multifunctional semiconductor field effect transistor test circuit and method | |
| CN211321248U (en) | High-precision voltage-regulating constant-current source system suitable for strong inductive load | |
| CN209072343U (en) | A kind of wide-range voltage and High-current output power-supply system | |
| CN208538011U (en) | A kind of high-precision pulse constant-current source | |
| CN112953171A (en) | High-precision power supply based on direct-current resistance measurement and implementation method thereof | |
| CN209730437U (en) | A kind of low-power laser and its driving circuit | |
| CN203645895U (en) | Load sampling circuit of non-isolated LED driving circuit | |
| CN207946716U (en) | A kind of numerical control constant-current source device | |
| CN208174540U (en) | A kind of negative voltage transition circuit | |
| CN210982689U (en) | Direct current electronic load device with constant current and constant voltage working modes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |