Test method and test device for electromagnetic PT monitoring simulation

Abstract

The invention relates to the technical field of electrical equipment monitoring, and discloses a test method and a test device for electromagnetic PT monitoring simulation, three electromagnetic PTs are arranged in a cabinet body, and the test method comprises the following steps: acquiring monitoring values of the three electromagnetic PTs; comparing the three monitoring values with a standard value, and giving an alarm when the monitoring values exceed the multiple of the standard value; wherein when the three electromagnetic type PTs all give an alarm, it is judged that the three electromagnetic type PTs have a ground fault, or the three electromagnetic type PTs have a fault; when at least one electromagnetic type PT gives an alarm, it is judged that the electromagnetic type PT breaks down, the state of the electromagnetic type PT can be monitored in real time, the method better fits the actual situation, and the reliability of the research result is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment monitoring, and in particular to a test method and a test device for electromagnetic PT monitoring simulation. Background Art

[0002] Electromagnetic PT is an important electrical device that monitors characteristic quantities such as voltage and power, and is of great significance to the operating status and stability of the power grid. Online monitoring of the operating status of PT is a necessary measure to ensure the safe operation of the power grid. The PT cabinet is the actual cabinet where the PT is placed in the power station, usually containing three PTs, providing good electrical insulation for the PT and ensuring the stability of the PT operating environment. However, in the experimental research on PT status monitoring, scholars usually only conduct experimental research on a single PT, lacking consideration of the actual operating status and environment of the PT. Summary of the invention

[0003] The object of the present invention is to provide a test method and a test device for electromagnetic PT monitoring simulation, aiming to solve or improve at least one of the above-mentioned technical problems.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a test method for electromagnetic PT monitoring simulation, wherein three electromagnetic PTs are arranged in a cabinet, and the test method comprises:

[0005] Obtaining monitoring values ​​of the three electromagnetic PTs;

[0006] Comparing the three monitoring values ​​with the standard value, and generating an alarm when the monitoring value exceeds the standard value by a multiple;

[0007] When the three electromagnetic PTs all generate alarms, it is determined that the three electromagnetic PTs are grounded, or the three electromagnetic PTs themselves are faulty.

[0008] When at least one of the electromagnetic PTs generates an alarm, it is determined that the electromagnetic PT itself has a fault.

[0009] Optionally, the test method further includes calculating a normal value range of the primary side current as the standard value through a formula based on the original data of the electromagnetic PT.

[0010] Optionally, the formula is:

[0011]

[0012]

[0013] Where: I 2 is the secondary current;

[0014] U2 is the secondary side voltage;

[0015] S is the rated capacity;

[0016] n is the rated transformation ratio;

[0017] I 1 is the primary side current.

[0018] Optionally, the multiple is 3-6 times.

[0019] Optionally, the wiring method of the three electromagnetic PTs is a three-phase electrical wiring method.

[0020] Optionally, the wiring method of the three electromagnetic PTs is a single-phase electrical wiring method.

[0021] The present invention also provides an electromagnetic PT monitoring simulation test device, comprising:

[0022] An acquisition module, used for acquiring monitoring values ​​of the three electromagnetic PTs;

[0023] The determination module is used to compare the three monitoring values ​​with the standard value, and generate an alarm when the monitoring value exceeds the multiple of the standard value.

[0024] Optionally, the acquisition module and the determination module are integrated in a current monitoring box.

[0025] Optionally, there are three current monitoring boxes, which correspond to and are connected to the three electromagnetic PTs respectively.

[0026] Optionally, a plurality of partitions are provided in the cabinet, and the plurality of partitions divide the cabinet into three installation cavities. The three electromagnetic PTs are respectively arranged in the three installation cavities, and the installation cavities are provided with insulating sleeves for electrical insulation of the electromagnetic PTs during wiring.

[0027] The present invention discloses the following technical effects: by comparing the monitoring values ​​of three electromagnetic PTs with standard values, observing the number of electromagnetic PTs that generate alarms after an alarm is generated, it is convenient to comprehensively consider the operating status and environment of the three electromagnetic PTs, monitor the status of the electromagnetic PTs in real time, better fit the actual situation, and ensure the reliability of the research results. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 It is a front view of the test device of the present invention;

[0030] Figure 2 It is a side view of the test device of the present invention;

[0031] Figure 3 It is a circuit diagram of the three-phase electrical wiring method of the present invention;

[0032] Figure 4 It is the alarm multiple test chart of the present invention.

[0033] Figure 5 The present invention is a flow chart of the test method.

[0034] In the figure: 1. Electromagnetic PT; 2. Cabinet; 3. Current monitoring box; 4. Partition; 5. Insulating sleeve. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Reference Figure 1-Figure 5 The present invention provides a test method for electromagnetic PT monitoring simulation, wherein three electromagnetic PT1 are arranged in a cabinet 2, and the test method comprises:

[0038] Get the monitoring values ​​of three electromagnetic PT1s;

[0039] Compare the three monitoring values ​​with the standard values, and generate an alarm when the monitoring value exceeds the standard value by multiples;

[0040] When the three electromagnetic PT1s all generate alarms, it is determined that the three electromagnetic PT1s are grounded, or the three electromagnetic PT1s themselves are faulty;

[0041] When at least one electromagnetic PT1 generates an alarm, it is determined that the electromagnetic PT1 itself has a fault.

[0042] By comparing the monitoring values ​​of the three electromagnetic PT1s with the standard values ​​and observing the number of electromagnetic PT1s that generate alarms after an alarm is generated, it is convenient to comprehensively consider the operating status and environment of the three electromagnetic PT1s, monitor the status of the electromagnetic PT1 in real time, which is more in line with the actual situation and ensures the reliability of the research results.

[0043] In one embodiment of the present invention, the test method further comprises calculating the normal value range of the primary side current as the standard value based on the original data of the electromagnetic PT1 by a formula.

[0044] The original data includes primary side rated voltage, rated capacity, rated transformation ratio, accuracy level, ratio difference, etc.

[0045] Further, in this embodiment, a group of electromagnetic PT1s from a certain factory is selected, the model is JDZ10-20: the original data of electromagnetic PT1 is obtained according to the manufacturer and the electric field operation data, the rated capacity of JDZX10-20 voltage transformer is 30VA, the rated voltage of the primary side is 20kV, the rated transformation ratio is 200:1, the accuracy level is 0.2, and the ratio difference of the error test is shown in Table 1:

[0046] Table 1 Error test (load power factor cosθ=0.8)

[0047]

[0048] In one embodiment of the present invention, the formula for calculating the electromagnetic PT1 is as follows, in combination with the above raw data:

[0049]

[0050]

[0051] Where: I 2 is the secondary side current, which is 100V in this embodiment;

[0052] U 2 is the secondary voltage, which is 30VA in this embodiment;

[0053] S is the rated capacity, which is 200 in this embodiment;

[0054] n is the rated transformation ratio, which is 100 in this embodiment;

[0055] I 1 is the primary side current.

[0056] From this calculation, it is concluded that the normal value range of the primary side current of the electromagnetic PT1 is 1.49mA-1.5mA, which is used as the standard value.

[0057] In one embodiment of the present invention, the multiple is 3-6 times. Specifically, preferably 5 times, the real-time monitoring alarm value is set to 5 times the normal value, i.e. 7.5 mA, in combination with the above standard value.

[0058] Furthermore, normal PTs and PTs with different inter-turn short-circuit defects were set for experiments. The PTs with inter-turn short-circuit defects were short-circuited with solder during the manufacturing stage, and the number of short-circuit turns was set to 0.05%, 0.1%, and 0.3% of the total number of turns. The primary side current, secondary side voltage, secondary side current and other data were obtained under different voltages. The secondary side voltage was used to determine whether the PT could work normally. When the secondary side voltage deviation did not exceed ±2% of the rated voltage (i.e., 98V to 102V), the PT was considered to be able to work normally. In this case, the severity of the defect was determined based on the size of the primary side current.

[0059] Table 1 Normal PT primary current

[0060] Primary voltage(kV) Primary current (mA) Secondary voltage (V) Secondary current (mA) 4 0.1 20.4 0.4 8 0.3 40.5 0.9 12 0.4 60.4 1.4 16 0.6 80.9 1.9 20 1 100.9 2.3

[0061] Table 2 Primary current of PT with 0.05% turn-to-turn short circuit defect

[0062]

[0063]

[0064] Table 3 PT primary current with 0.1% turn-to-turn short circuit defect

[0065] Primary voltage(kV) Primary current (mA) Secondary voltage (V) Secondary current (mA) 4 4.3 20.2 0.5 8 8.2 40.3 1 12 11.5 61.3 1.5 16 14.3 80.8 2 20 16.8 101.2 2.5

[0066] Table 4 PT primary current with 0.3% turn-to-turn short circuit defect

[0067] Primary voltage(kV) Primary current (mA) Secondary voltage (V) Secondary current (mA) 4 7.6 20.2 0.6 8 14.3 40.3 1.2 12 20.6 60.2 1.7 16 25.6 80 2.1 20 28.7 100.1 2.7

[0068] According to the test results, the relationship between the primary current data and the short-circuit turns ratio at 20 kV is fitted, as shown in Table 5 and Figure 4 , and the fitting calculation formula is: y = -0.02×(1-e 0.08x ). Where y represents the short-circuit turns ratio, and x represents the primary current. By fitting the formula, it is calculated that when x=5mA, y=0.01%. When the primary current is set to 5 times the normal value, i.e. 5mA, the detection limit of the short-circuit turns ratio can be reduced to 0.01%, which is crucial for early detection of PT latent defects.

[0069] Table 5 20kV fitting data

[0070] Primary current (mA) Short circuit turns ratio (%) 1 0 9.3 0.05 16.8 0.1 28.7 0.3

[0071] In one embodiment of the present invention, the connection method of the three electromagnetic PT1s is a three-phase electrical connection method.

[0072] In one embodiment of the present invention, the connection mode of the three electromagnetic PT1s is a single-phase electrical connection mode.

[0073] Different wiring methods are used to study the operating status of electromagnetic PT1 under different wiring methods, and obtain different change laws of characteristic quantities.

[0074] The present invention also provides an electromagnetic PT monitoring simulation test device, comprising:

[0075] An acquisition module is used to obtain the monitoring values ​​of three electromagnetic PT1s;

[0076] The judgment module is used to compare the three monitoring values ​​with the standard values ​​and generate an alarm when the monitoring value exceeds the standard value by multiples.

[0077] In one embodiment of the present invention, the acquisition module and the determination module are integrated into the current monitoring box 3 .

[0078] The calculated standard value is input into the current monitoring box 3, and the operating status of the electromagnetic PT1 is monitored in real time by the current monitoring box 3, and the monitoring value is compared with the standard value in real time. When the monitoring value exceeds the standard value by 5 times, an alarm is generated.

[0079] In one embodiment of the present invention, there are three current monitoring boxes 3, which correspond to and are connected to three electromagnetic PT1 respectively.

[0080] The three current monitoring boxes 3 monitor the three electromagnetic PT1s separately.

[0081] In one embodiment of the present invention, a plurality of partitions 4 are provided in the cabinet 2, and the plurality of partitions 4 divide the cabinet 2 into three installation cavities. Three electromagnetic PT1s are respectively arranged in the three installation cavities, and insulating sleeves 5 are provided in the installation cavities for electrical insulation of the electromagnetic PT1 during wiring.

[0082] Specifically, the three electromagnetic PT1s are distributed in a manner of one on the upper layer and two on the lower layer, and the three current monitoring boxes 3 are distributed and located in three installation cavities one by one.

[0083] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0084] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A test method for electromagnetic PT monitoring simulation, characterized in that: Three electromagnetic PTs (1) are arranged in a cabinet (2). The test method comprises: Obtaining monitoring values ​​of the three electromagnetic PTs (1); Comparing the three monitoring values ​​with the standard value, and generating an alarm when the monitoring value exceeds the standard value by a multiple; When the three electromagnetic PTs (1) generate an alarm, it is determined that the three electromagnetic PTs (1) are grounded, or the three electromagnetic PTs (1) themselves are faulty. When at least one of the electromagnetic PTs (1) generates an alarm, it is determined that the electromagnetic PT (1) itself has a fault.

2. The electromagnetic PT monitoring simulation test method according to claim 1 is characterized in that: The test method further comprises calculating the normal value range of the primary side current as the standard value through a formula based on the original data of the electromagnetic PT (1).

3. The electromagnetic PT monitoring simulation test method according to claim 2 is characterized in that: The formula is: Where: I2 is the secondary side current; U2 is the secondary voltage; S is the rated capacity; n is the rated transformation ratio; I1 is the primary side current.

4. The electromagnetic PT monitoring simulation test method according to claim 1 is characterized in that: The multiple is 3-6 times.

5. The electromagnetic PT monitoring simulation test method according to claim 1, characterized in that: The connection method of the three electromagnetic PTs (1) is a three-phase electrical connection method.

6. The electromagnetic PT monitoring simulation test method according to claim 1, characterized in that: The connection mode of the three electromagnetic PTs (1) is a single-phase electrical connection mode.

7. An electromagnetic PT monitoring simulation test device, used to implement an electromagnetic PT monitoring simulation test method according to any one of claims 1 to 6, characterized in that: include; An acquisition module, used for acquiring monitoring values ​​of the three electromagnetic PTs (1); The determination module is used to compare the three monitoring values ​​with the standard value, and generate an alarm when the monitoring value exceeds the multiple of the standard value.

8. The electromagnetic PT monitoring simulation test device according to claim 7, characterized in that: The acquisition module and the determination module are integrated in the current monitoring box (3).

9. The electromagnetic PT monitoring simulation test device according to claim 8, characterized in that: There are three current monitoring boxes (3), which correspond to and are connected to the three electromagnetic PTs (1) one by one.

10. The electromagnetic PT monitoring simulation test device according to claim 7, characterized in that: A plurality of partitions (4) are arranged in the cabinet (2), and the plurality of partitions (4) divide the cabinet (2) into three installation cavities. The three electromagnetic PTs (1) are arranged in the three installation cavities respectively, and the installation cavities are provided with insulating sleeves (5) for electrical insulation when the electromagnetic PTs (1) are connected.

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