Test system for detecting voltage and current leading-in direction by low-voltage simulation load
By using a low-voltage simulation of the load voltage and current introduction direction in the feeder of the electrified railway traction substation, the problem of inability to effectively detect the voltage and current introduction direction in the existing technology is solved, and higher safety and detection accuracy are achieved, while reducing detection costs.
Patent Information
- Application Number
- CN202421783079.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-26
AI Technical Summary
The prior art cannot effectively detect the voltage and current introduction directions in the feeder of the electrified railway traction substation, resulting in the quadrilateral impedance protection refusing to move when the voltage and current introduction direction is incorrect, which poses serious safety hazards.
A low-voltage analog load detection voltage and current introduction direction is used to use a test system. The system sets a voltage transformer, current transformer and external load, and uses a boost upstream module to amplify the current and voltage values, combines the feeder protection device to identify the load impedance angle, and judges the correctness of the voltage and current wiring.
It improves the safety and accuracy of inspection, reduces the detection cost, avoids high safety requirements of high-voltage loads, and shortens the test cycle.
Smart Images
Figure CN222926779U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of detecting the introduction direction of feeder current and voltage in railway traction substations, and particularly relates to a test system for detecting the introduction direction of voltage and current by a low-voltage analog load. Background Art
[0002] For the feeder of an electrified railway traction substation, the catenary line adopts a quadrilateral directional impedance protection as the main protection. When the introduction direction of voltage and current is incorrect, the protection will refuse to operate. If a fault occurs in the catenary line at this time, the quadrilateral directional impedance protection as the main protection will not issue a high-voltage circuit breaker tripping instruction, which has relatively serious potential safety hazards. Therefore, for newly built or rebuilt electrified railway feeders, before the line is officially opened to traffic, it is necessary to carry a load on the high-voltage side to verify whether the introduction direction of voltage and current is correct. This method requires setting a high-voltage load to form a high-voltage current closed loop. However, the high-voltage load has high safety requirements, high test costs, and a long test organization cycle. Content of the Utility Model
[0003] The purpose of the utility model is to provide a test system for detecting the introduction direction of voltage and current by a low-voltage analog load. This system uses low-voltage electricity to simulate high-voltage electricity to detect the introduction direction of voltage and current. As a pre-opening test, it has high safety, reduces the detection cost, and has good application prospects.
[0004] To achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A test system for detecting the introduction direction of voltage and current by a low-voltage analog load includes a voltage transformer arranged on the high-voltage bus side, a current transformer arranged on the high-voltage feeder branch, and an external load. A boost and current boost module is arranged in the secondary circuits of the current transformer and the voltage transformer. The boost and current boost module is used to boost the secondary current generated by the current transformer and boost the secondary voltage generated by the voltage transformer. A feeder protection device is arranged at the output end of the boost and current boost module. The feeder protection device is used to identify the impedance angle of the external load.
[0006] Preferably, the power of the external load is not less than 1 kW.
[0007] Preferably, a low-voltage introduction point is electrically connected to the high-voltage bus side. The low-voltage introduction point connects 220V alternating current to the high-voltage bus.
[0008] Preferably, the boost and current boost module includes a boost transformer and a current boost transformer. The boost transformer is used to boost the voltage on the secondary side of the voltage transformer, and the current boost transformer is used to boost the current on the secondary side of the current transformer.
[0009] Preferably, the voltage boost ratio of the step-up transformer is not less than 1:10; the current boost ratio of the current boost transformer is not less than 1:10.
[0010] In the present utility model, the system tests the current and voltage directions on the high-voltage side in a manner of simulating high voltage with low voltage, ensuring correct power supply for the feeders of newly built or renovated electrified railways, improving the safety of the test, and reducing the test cost. The provided step-up and current boost module can increase the values of the current and voltage to be measured, making the voltage and current display more intuitive, and being able to distinguish well from the interfering voltage and current, improving the detection accuracy of the system. Brief Description of the Drawings
[0011] Figure 1 is a schematic diagram of the wiring principle of the system of the present utility model;
[0012] Figure 2 is a schematic diagram of the wiring principle of the step-up and current boost module of the present utility model;
[0013] In the figure: 1. High-voltage feeder branch; 2. Current transformer; 3. Voltage transformer; 4. External load; 5. High-voltage busbar; 6. Step-up and current boost module; 7. Feeder protection device; 60. Step-up transformer; 61. Current boost transformer. Detailed Embodiment
[0014] The following further describes the present utility model in conjunction with the drawings:
[0015] As Figure 1 and Figure 2 shown, a test system for detecting the voltage and current introduction directions of a low-voltage analog load includes a voltage transformer 3 provided on the side of the high-voltage busbar 5, a current transformer 2 and an external load 4 provided on the high-voltage feeder branch 1. The power of the external load 4 is not less than 1 kW and generates a primary current. The current transformer 2 is used to generate a secondary current, and the voltage transformer 3 is used to generate a secondary voltage. A low-voltage introduction point is electrically connected to the high-voltage busbar 5. The low-voltage introduction point connects 220V alternating current to the high-voltage busbar 5. During the test, the high-voltage busbar 5 is not connected to high voltage, but 220V alternating current is connected through the low-voltage introduction point, improving the safety performance of the test. Through the current generated by the external load 4, the current transformer 2 generates a smaller secondary current, and the voltage transformer 3 generates a smaller secondary voltage. The phase angle of the smaller voltage and current is close to the true load impedance angle.
[0016] At one end of the current transformer 2 and the voltage transformer 3, there is a boosting and current-increasing module 6. The boosting and current-increasing module 6 is used to increase the current of the secondary current generated by the current transformer 2 and boost the secondary voltage generated by the voltage transformer 3. Specifically, the boosting and current-increasing module 6 includes a boosting transformer 60 and a current-increasing transformer 61. The boosting transformer 60 is used to boost the voltage on the secondary side of the voltage transformer 3, and the current-increasing transformer 61 is used to increase the current on the secondary side of the current transformer 2. The boosting ratio of the boosting transformer 60 is not less than 1:10; the current-increasing ratio of the current-increasing transformer 61 is not less than 1:10. In this embodiment, the boosting ratio of the boosting transformer 60 is selected as 1:15; the current-increasing ratio of the current-increasing transformer 61 is selected as 1:15. The relatively small secondary voltage generated by the voltage transformer 3 and the relatively small secondary current generated by the current transformer 2 are amplified by boosting and current-increasing through the boosting and current-increasing module 6. Then, the feeder protection device 7 identifies the load impedance angle based on the amplified voltage and current, and is used to judge the wiring correctness of the voltage and current wiring of the quadrilateral directional impedance protection.
[0017] At the output end of the boosting and current-increasing module 6, there is a feeder protection device 7. The feeder protection device 7 is used to identify the impedance angle of the external load 4. When the resistance value read by the feeder protection device 7 is positive, it can be explained that the wiring of the voltage and current wiring of the quadrilateral directional impedance protection is correct, and the protection can be started normally. The feeder protection device 7 selects a mature product on the market and will not be described in detail in this specification.
[0018] The boosting transformer 60 has two input terminals b1 and b2. b1 and b2 are electrically connected to both ends of the voltage transformer 3 through a cable. The boosting transformer 60 has two output terminals B1 and B2. B1 and B2 are electrically connected to the two high-voltage bus voltage secondary wire number terminals of the feeder protection device 7 through a cable. Specifically, B1 is electrically connected to the voltage secondary wire number terminal A610, and B2 is electrically connected to the voltage secondary wire number terminal N610. Different substations have different high-voltage bus voltage secondary wire number terminals and current secondary wire number terminals, and the wiring is carried out according to the on-site situation during measurement.
[0019] The current-increasing transformer 61 has two input terminals d1 and d2. d1 and d2 are electrically connected to both ends of the current transformer 2 through a cable. The current-increasing transformer 61 has two output terminals D1 and D2. D1 and D2 are electrically connected to the two current secondary wire number terminals of the feeder protection device 7 through a cable. Specifically, D1 is electrically connected to the current secondary wire number terminal A421, and D2 is electrically connected to the current secondary wire number terminal N421.
[0020] The above embodiments are only several descriptions of the concept and implementation of the present invention, and do not limit it. Under the concept of the present invention, the technical solutions without substantial transformation are still within the protection scope.
Claims
1. A test system for detecting voltage and current introduction direction of a low voltage simulated load, characterized in that: It includes a voltage transformer arranged on the high-voltage bus side, a current transformer arranged on the high-voltage feeder branch, and an external load. A boost and current increasing module is arranged in the secondary circuit of the current transformer and the voltage transformer. The boost and current increasing module is used to increase the secondary current generated by the current transformer and the secondary voltage generated by the voltage transformer. A feeder protection device is arranged at the output end of the boost and current increasing module. The feeder protection device is used to identify the impedance angle of the external load.
2. The test system for detecting voltage and current introduction direction of a low voltage simulated load according to claim 1, characterized in that: The power of the external load is not less than 1 kW.
3. The test system for detecting voltage and current introduction direction of a low voltage simulated load according to claim 1 or 2, characterized in that: A low voltage lead-in point is electrically connected to the high voltage bus side, and the low voltage lead-in point connects 220V AC power to the high voltage bus.
4. The test system for detecting voltage and current introduction direction of low voltage simulated load according to claim 1, characterized in that: The voltage and current boosting module comprises a voltage boosting transformer and a current boosting transformer. The voltage boosting transformer is used to boost the voltage on the secondary side of the voltage transformer, and the current boosting transformer is used to boost the current on the secondary side of the current transformer.
5. The test system for detecting voltage and current introduction direction of low voltage simulated load according to claim 4, characterized in that: The voltage step-up ratio of the step-up transformer is not less than 1:10; the current step-up ratio of the current step-up transformer is not less than 1:10.