CN216351162U - Portable high-precision measuring device for unbalance rate of offshore wind power transformer winding - Google Patents
Portable high-precision measuring device for unbalance rate of offshore wind power transformer winding Download PDFInfo
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- CN216351162U CN216351162U CN202122087370.1U CN202122087370U CN216351162U CN 216351162 U CN216351162 U CN 216351162U CN 202122087370 U CN202122087370 U CN 202122087370U CN 216351162 U CN216351162 U CN 216351162U
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Abstract
The utility model provides a portable high-precision measuring device for the unbalance rate of an offshore wind power transformer winding, which comprises a constant current source, a microprocessor, a display screen and a voltage measuring device, wherein the display screen and the voltage measuring device are connected with the microprocessor, two measuring ends of the voltage measuring device are respectively connected with two ends of the constant current source, the constant current source is connected with a first leading-out end and a second leading-out end, the first leading-out end and the second leading-out end are respectively used for connecting two ends of the transformer winding to be measured, and an additional resistor is connected in series between the first leading-out end/the second leading-out end and the constant current source. This scheme has simple structure with low costs, and small in size is portable, advantages such as convenient to use can reduce time constant through for experimental return circuit series resistance to improve experimental speed, satisfy the strict requirement of marine test to test time.
Description
Technical Field
The utility model belongs to the technical field of direct current resistance tests of marine transformer windings, and particularly relates to a portable high-precision measuring device for the unbalance rate of marine wind power transformer windings.
Background
The direct-current resistance test of the transformer winding is one of basic items of delivery, handover and preventive tests, and is also an important inspection item after the transformer fails, and the test purpose is as follows: checking the welding quality of the transformer winding joint; checking whether the transformer winding has turn-to-turn short circuit or not and checking whether the transformer winding has turn-to-turn short circuit or not; checking whether the contact of each tapping position of all the tapping switches is good or not; checking whether the actual position of the tap changer conforms to the indication; checking whether the outgoing line is broken or not; checking whether a winding wound by a plurality of strands of wires has a short strand condition; and checking whether the contact between the winding lead-out wire and the conducting rod is good or not. Therefore, for a long time, measuring the direct-current resistance of the winding is considered as one of the main means for examining the longitudinal insulation of the transformer, and sometimes even the only method for judging the connection condition of the current loop.
The transformer winding can be equivalent to an inductor L and a resistor R which are connected in series, when the resistance test is carried out on the transformer winding, a charging process from zero to a stable value exists through direct current of the winding, only when the current is stable, the accurate test can be carried out, and the current needs a certain time when being stable. The offshore test environment is worse than the land test environment, the offshore test requires the conditions of 'no strong wind, no sea wave and no rain', while the southeast coast of China is influenced by marine climate and continental climate alternately and frequently encounters extreme weather such as typhoon, heavy rain, tide and billow, so that the time of the offshore test must be shortened, and the time is in conflict, so that the stabilization time required by the direct current resistance test of the winding of the offshore transformer is very necessary to be shortened.
The length of the settling time depends on a plurality of factors, wherein the most important factor is the time constant, i.e. the ratio of the inductance L to the resistance R, the smaller the time constant is, the shorter the settling time is, but generally, the transformer winding has a large L and a small R, resulting in a long settling time. At present, the method for shortening the stabilization time mainly starts with reducing the inductance L or increasing the resistance R, the reduction of the inductance L is mainly realized by increasing the current, and the increase of the resistance R is mainly realized by connecting the resistance in series on the test loop of the transformer winding. The current increasing mode can cause the problem of excessive testing remanence due to overlarge testing current to a certain extent, so that the mode of series resistance is generally adopted at present. However, the way of connecting resistors in series also has certain defects, such as the resistors themselves will have certain influence on the measurement result, and need to be further improved.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the problems and provides a portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer.
In order to achieve the purpose, the utility model adopts the following technical scheme:
the utility model provides a portable high accuracy measuring device of marine wind power transformer winding unbalance rate, includes constant current source, microprocessor and display screen, the voltage measurement device who is connected with microprocessor, two measuring terminals of voltage measurement device are connected respectively at the both ends of constant current source, the constant current source be connected with first drawing end and second and draw forth the end, first drawing end and second draw forth the end and be used for connecting the both ends of the transformer winding that awaits measuring respectively, just first drawing end/second and drawing forth and establish ties between end and the constant current source and have additional resistance.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the microprocessor is used for receiving a voltage value measured by the voltage measuring device and displaying the measured voltage value on the display screen.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the microprocessor stores the resistance value of the additional resistor, and is used for obtaining the measured resistance value according to the voltage value obtained by the voltage measuring device and displaying the measured resistance value on the display screen.
In the portable high-precision measuring device for the unbalance rate of the offshore wind power transformer winding, the additional resistor is a low-temperature drift low-resistance resistor.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the constant current source is used for providing a large current which is greater than or equal to 10A.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the constant current source is a multi-gear constant current source with a multi-gear constant direct current power supply.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the microprocessor is connected with a relay, and a normally open switch K1 of the relay is connected with the additional resistor in parallel.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the relay is further provided with a normally closed switch K2 connected with the additional resistor in series, and the normally open switch K1 is connected with the normally closed switch K2 and the additional resistor in parallel.
In the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer, the device further comprises a scanning camera connected to the microprocessor.
The utility model has the advantages that:
1. the structure is simple, the cost is low, and the use is convenient and quick;
2. the time constant can be reduced for testing the loop series resistance, so that the testing speed is improved, and the strict requirement of an offshore test on the testing time is met;
3. the large current source is used for measurement, so that the measurement speed is higher, and the strict requirement of the offshore test on the test time is further met;
4. the influence of the additional resistor on the measurement result can be reduced as much as possible by adopting the low-temperature drift resistor with low resistance value, so that the test precision is improved;
5. the relay loop is used for disconnecting the additional resistor after the current is stable, and the constant current source is adopted, so that the voltage is only influenced after one resistance value is disconnected, the winding transformer still has stable current, and the inductor only obstructs the change of the current, therefore, the change of the voltage is almost instantly finished, the voltage value can be read in a very short time, the measurement time can be shortened, the influence of the additional resistor on the test result can be completely avoided, and the test precision is improved.
6. Because the reading of the voltage measuring device is carried out after the additional resistor is disconnected, only the voltage changes at the moment, and the voltage change is almost instantly finished, the circuit is stable, the jumping voltage value is not easy to occur, the voltage seen by a user is the final accurate voltage, the problem of inaccurate data caused by unstable copying is avoided, and the practical application effect is outstanding.
Drawings
FIG. 1 is a schematic structural diagram of a portable high-precision measuring device for measuring the unbalance rate of windings of a wind power transformer on the sea in an embodiment of the utility model;
FIG. 2 is a block diagram of a circuit structure of a portable high-precision measuring device for measuring the unbalance rate of windings of a wind power transformer in the middle sea area according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a portable high-precision measuring device for measuring the unbalance rate of windings of an offshore wind turbine in the second embodiment of the present invention;
fig. 4 is a block diagram of a circuit structure of a portable high-precision measuring device for measuring the winding imbalance rate of an offshore wind turbine transformer in the second embodiment of the present invention.
Reference numerals: a large current source 1; a voltage dividing resistor 2; a voltage measuring device 3; a first leading-out terminal 4; a second lead-out terminal 5; a transformer winding 6 to be tested; a microprocessor 7; a display screen 8; and a relay 9.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Example one
As shown in fig. 1 and fig. 2, the present embodiment provides a portable high-precision measurement device for the unbalance rate of the winding of the offshore wind power transformer, which includes a constant current source 1, a microprocessor 7, a display screen 8 connected to the microprocessor 7, and a voltage measurement device 3. The constant current source 1 is connected with a first leading-out end 4 and a second leading-out end 5, the first leading-out end 4 and the second leading-out end 5 are respectively used for being connected with two ends of a transformer winding 6 to be tested so as to provide current for the transformer winding 6 to be tested to be connected with the constant current source 1, and an additional resistor 2 is connected in series between the first leading-out end 4/the second leading-out end 5 and the constant current source 1. Two measuring ends of the voltage measuring device 3 are respectively connected with two ends of the constant current source 1. The voltage value measured by the voltage measuring device 3 is the sum of the voltage of the transformer winding 6 to be measured and the voltage of the additional resistor 2.
The microprocessor 7 is used for receiving the voltage value measured by the voltage measuring device 3 and displaying the measured voltage value on the display screen 8. Then, the tester calculates the measured resistance value of the transformer winding 6 to be measured by ohm law.
Or, the microprocessor 7 stores the resistance value of the additional resistor 2, and the microprocessor 7 automatically obtains the measured resistance value through ohm's law when receiving the voltage value measured by the voltage measuring device 3 and displays the measured resistance value on the display screen 8:
Rtotal resistance value＝UAnd/Isource，RWinding wire＝RTotal resistance value-RAdditional resistance
UAnda voltage value measured by the voltage measuring device 3;
IsourceA current value supplied to the constant current source 1;
Rwinding wireThe measured resistance value of the transformer winding 6 to be measured;
Radditional resistanceIs the resistance value of the additional resistor 2.
Preferably, the additional resistor 2 used in the present embodiment is a low resistance resistor with low temperature drift and high power. Particularly preferably, a low temperature drift resistance with an accuracy of less than 10ppm is used. The additional resistor is a low-temperature drift resistor, the resistance value of the low-temperature drift resistor changes very little with the temperature, and a low-resistance resistor is further adopted, so that the additional resistor can be guaranteed to have very low temperature rise in the test process, the influence of the temperature rise on the resistance value of the additional resistor is avoided as far as possible, and the actual resistance value of the additional resistor is consistent with the stored resistance value in the test process.
Further, in order to further increase the measuring speed, the constant current source 1 is used to provide a large current of 10A or more, for example, 20A, 50A, 80A, etc., and the current is selected so as not to generate excessive remanence.
Preferably, a multi-gear constant current source is adopted, and a user can select one gear to test according to the needs of the user and the specific situation of the transformer winding 6 to be tested.
The measuring device of the embodiment is used for testing the series resistance of the loop, and can reduce the time constant, thereby improving the testing speed and meeting the strict requirement of the offshore test on the testing time. And further, the low-temperature drift resistor with low resistance is adopted, so that the influence of the additional resistor on the measurement result can be reduced as much as possible, and the test precision is improved.
Example two
As shown in fig. 3 and 4, the present embodiment is similar to the embodiment, except that the microprocessor 7 of the present embodiment is connected with the relay 9, the normally closed switch K2 of the relay 9 is connected in series with the additional resistor 2, and the normally open switch K1 is connected in parallel with the normally closed switch K2 and the additional resistor 2.
When the portable high-precision measuring device is put into use, the quick testing method of the portable high-precision measuring device for the unbalance rate of the winding of the offshore wind power transformer can be as follows:
s1, respectively connecting two ends of a transformer winding 6 to be tested to two leading-out ends of the device;
s2, opening a power switch of the constant current source 1, closing a normally open switch K1 and opening a normally closed switch K2 after a set time; the normally closed switch K2 is opened, so that the influence of the additional resistor 2 on the measurement can be completely avoided;
s3, the voltage measuring device 3 starts to read the voltage value and sends the result to the microprocessor 7;
and S4, calculating the resistance value of the transformer winding 6 to be detected according to the voltage value by the microprocessor 7 and displaying the resistance value on a display screen. This is achieved byAccording to ohm's law RWinding wire＝UAnd/IsourceAnd obtaining the resistance value of the transformer winding 6 to be tested.
The power switch is connected in series between the constant current source 1 and the measuring transformer winding 6 and is arranged on the shell of the measuring device, a user connects the measuring transformer winding 6 to toggle the power switch so as to connect a direct current power supply for the measuring transformer winding 6, and when the constant current source 1 is a multi-gear constant current source, a knob type power switch can be adopted.
The measuring device of the present embodiment requires a much shorter settling time than the prior art measuring device when it is directed to the same transformer winding. However, the same measuring device may need different settling times for different transformer windings, and the measuring device is no exception, so that the scheme preferably stores a time-transformer table (table 1) and a time-model table (table 2) in the microprocessor, and the table 2 is used for recording different settling times, which are required by the measuring device for different models of transformers and are obtained by testing by a manufacturer or other personnel in advance. Table 1 is used to record the average time required for testing different capacity, type transformers organized by the manufacturer or other personnel using the measuring device.
The tester can input the transformer model of the transformer winding 6 to be tested before testing the transformer winding 6 to be tested by using the measuring device, and the microprocessor 7 calls corresponding time as set time according to the transformer model input by a user. When the user does not know the model of the transformer to be tested or the time of the corresponding model of the transformer to be tested is not recorded in the table 2, the user can also input the capacity and the type of the transformer, and the microprocessor 7 calls the corresponding time as the set time according to the capacity and the type of the transformer.
Table 1: time-transformer meter
| Type of transformer | Time |
| SJL-1000/10 | 1.8s |
| SFSZ9-31500/110 | 2.8s |
| SCB9-2000/0.4～0.23Dyn11 | 1.1s |
| … | … |
Table 2: time-model table
| Transformer capacity/type | Time |
| 2000KVA dry transformer | 1.1s |
| 31500KVA power transformer | 2.8s |
| 1000KVA oil-immersed transformer | 1.8s |
| … | … |
Furthermore, the measuring device can also be provided with a scanning camera connected to the microprocessor 7, and the scanning camera is used for scanning a nameplate on the transformer winding to quickly acquire the type of the transformer winding and the capacity and the type of the transformer, so that a user does not need to input the type or the type of the transformer by himself, and the user is helped to quickly enter a test state.
The measuring device provided by the embodiment has the advantages of simple structure, low cost, high testing speed and the like, and solves the problems of overlarge volume, overweight mass, overlong testing time, inaccurate testing data and large deviation of the offshore wind power transformer winding direct current resistance testing equipment. In addition, in the embodiment, the relay loop is used for disconnecting the additional resistor after the current is stable, and the voltage value can be read in a very short time, so that the measurement time can be shortened, the influence of the additional resistor on the test result can be completely avoided, and the test precision is improved. And because the reading of the voltage measuring device is carried out after the set time and the additional resistor are disconnected, only the voltage changes, and the voltage change is almost instantly finished, the circuit is stable, the voltage value of jump is not easy to occur, the voltage seen by a user is the final accurate voltage, the problem of inaccurate data caused by unstable copying is avoided, and the practical application effect is prominent.
The accurate obtaining of the unbalance rate depends on the accurate measurement of the resistance values of the windings, and the winding resistance values can be quickly and accurately obtained through the scheme, so that the accurate unbalance rate can be obtained, and a user can manually calculate the unbalance rate according to the measured resistance values of the windings of the transformer. Of course, the microprocessor 7 may also embed an imbalance rate calculation algorithm, and the imbalance rate of the corresponding transformer is calculated by the microprocessor 7 directly according to the measured resistance values of the phase windings.
The specific embodiments described herein are merely illustrative of the spirit of the utility model. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the utility model as defined in the appended claims.
Although a large current source 1 is used more here; a voltage dividing resistor 2; a voltage measuring device 3; a first leading-out terminal 4; a second lead-out terminal 5; a transformer winding 6 to be tested; a microprocessor 7; a display screen 8; and a relay 9. Etc., but does not exclude the possibility of using other terms. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.
Claims (9)
1. The utility model provides a portable high accuracy measuring device of marine wind power transformer winding unbalance rate, its characterized in that, include constant current source (1), microprocessor (7) and display screen (8), voltage measurement device (3) be connected with microprocessor (7), two measuring terminals of voltage measurement device (3) are connected respectively at the both ends of constant current source (1), constant current source (1) be connected with first draw forth end (4) and second and draw forth end (5), first draw forth end (4) and second and draw forth end (5) and be used for connecting the both ends of awaiting measuring transformer winding (6) respectively, just first draw forth end (4)/second and draw forth and establish ties between end (5) and the constant current source (1) and have additional resistance (2).
2. Portable high-precision measurement device for the unbalance rate of windings of offshore wind power transformers according to claim 1, characterized in that said microprocessor (7) is adapted to receive the voltage values measured by the voltage measurement device (3) and to display the measured voltage values on a display screen (8).
3. Portable high-precision measurement device for the unbalance rate of windings of offshore wind power transformers according to claim 1, characterized in that the microprocessor (7) stores the resistance value of the additional resistor (2) and the microprocessor (7) is configured to obtain the measured resistance value from the voltage value measured by the voltage measurement device (3) and to display the measured resistance value on the display screen (8).
4. Portable high-precision measurement device for the unbalance rate of offshore wind power transformer windings according to claim 2 or 3, characterized in that the additional resistor (2) is a low temperature drift low resistance resistor.
5. Portable high-precision measurement device for offshore wind power transformer winding unbalance rates according to claim 4, characterized in that the constant current source (1) is used for supplying a large current of 10A or more.
6. Portable high-precision measurement device for offshore wind power transformer winding unbalance rates according to claim 5, characterized in that the constant current source (1) is a multi-step constant current source with a multi-step constant direct current power supply.
7. Portable high-precision measurement device for the unbalance rate of offshore wind power transformer windings according to claim 1, characterized in that the microprocessor (7) is connected with a relay (9), and a normally open switch K1 of the relay (9) is connected in parallel with the additional resistor (2).
8. Offshore wind power transformer winding unbalance rate portable high accuracy measurement device according to claim 7, characterized in that said relay (9) further has a normally closed switch K2 in series with said additional resistor (2), and said normally open switch K1 is in parallel with normally closed switch K2 and additional resistor (2).
9. Offshore wind power transformer winding imbalance ratio portable high-precision measurement device according to claim 8, characterized by further comprising a scanning camera connected to the microprocessor (7).
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| Application Number | Priority Date | Filing Date | Title |
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| CN202122087370.1U CN216351162U (en) | 2021-08-31 | 2021-08-31 | Portable high-precision measuring device for unbalance rate of offshore wind power transformer winding |
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| CN202122087370.1U CN216351162U (en) | 2021-08-31 | 2021-08-31 | Portable high-precision measuring device for unbalance rate of offshore wind power transformer winding |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777534A (en) * | 2021-08-31 | 2021-12-10 | 浙江大成中孚电力技术发展有限公司 | High-precision measurement device for unbalance rate of marine transformer winding and rapid test method |
| CN118214032A (en) * | 2024-05-22 | 2024-06-18 | 浙江大成中孚电力技术发展有限公司 | Frequency stability control method and system for offshore wind power access power grid |
-
2021
- 2021-08-31 CN CN202122087370.1U patent/CN216351162U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777534A (en) * | 2021-08-31 | 2021-12-10 | 浙江大成中孚电力技术发展有限公司 | High-precision measurement device for unbalance rate of marine transformer winding and rapid test method |
| CN118214032A (en) * | 2024-05-22 | 2024-06-18 | 浙江大成中孚电力技术发展有限公司 | Frequency stability control method and system for offshore wind power access power grid |
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