10kV overhead line single-phase grounding test device based on power distribution network

Abstract

The utility model discloses a 10kV overhead line single-phase grounding test device based on a power distribution network, and belongs to the technical field of power distribution network grounding fault simulation. Which comprises a main controller, a fault type switching module and a grounding mode selection module, the output end of the main controller is respectively connected with the fault type switching module and the grounding mode selection module, and is characterized in that a change-over switch is arranged in the fault type switching module and is connected with a plurality of different actual grounding scenes; the 10kV overhead line is grounded with one of the actual grounding scenes through the change-over switch. According to the 10kV overhead line single-phase grounding test device based on the power distribution network, the 10kV overhead line is connected with an actual grounding scene through a change-over switch in the fault type switching module, and compared with a mode of simulating different grounding scenes through resistors in the prior art, accurate simulation of different grounding fault types such as grounding faults is achieved.

Description

Technical Field

[0001] A single-phase grounding test device based on a 10kV overhead line in a power distribution network belongs to the field of power distribution network grounding fault simulation technology. Background Technology

[0002] 10kV overhead lines are a key component of medium-voltage distribution networks in power systems. These lines suspend conductors above the ground via poles, directly supplying power to operators. However, 10kV overhead lines are prone to grounding faults caused by factors such as tree contact, single-phase grounding due to tree branches touching the conductor, or broken branches pressing on the conductor, causing a line break. These faults can cause line tripping and affect power supply reliability. Therefore, designing a test to address grounding faults in 10kV overhead lines to improve the efficiency of research and testing is a commonly used technical approach in existing technologies.

[0003] In existing technologies, the most traditional grounding test method relies primarily on manual operation. This method suffers from numerous problems, including significant safety hazards, inconvenience, susceptibility to external environmental influences, and inaccurate parameter control. To address these issues, several technical solutions have emerged, such as:

[0004] The technical solutions described in the following Chinese invention patents are as follows: Application No. 202010120401.6, filed on February 26, 2020, entitled "A 10kV Closing Angle Control System and Precise Control Method"; Application No. 202310117442.3, filed on February 15, 2023, entitled "A Ground Fault Intelligent Generation Method and System"; and Application No. 202222439961.5, filed on September 15, 2022, entitled "A Multimode Feeder Automated Training Device".

[0005] Existing technologies, including the aforementioned solutions, mostly focus on grounding angle control and data acquisition. However, in practical operation, they still have the following shortcomings:

[0006] (1) There are still shortcomings in the selection of grounding methods and the simulation of grounding fault types. On the one hand, existing technologies mainly focus on adjusting the resistance value for grounding fault types. However, this method is difficult to reproduce the complex characteristics of real fault scenarios and cannot meet the test requirements of complex scenarios.

[0007] (2) The existing scheme is insufficient in terms of safety protection mechanism and ease of operation. On the one hand, it lacks a real-time monitoring and protection mechanism for abnormal situations (such as overcurrent, overvoltage, short circuit, etc.) during the test, which poses a safety hazard; on the other hand, the operation process is complicated, relying on manual adjustment or complex switch combinations, which is inefficient and difficult to achieve remote control and automated operation.

[0008] (3) Most existing devices do not fully consider remote control functions, and some operations still require operators to manually operate on site, which increases the operational risk. Utility Model Content

[0009] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a 10kV overhead line single-phase grounding test device based on the distribution network that connects the 10kV overhead line to the actual grounding scenario through the switching switch in the fault type switching module. Compared with the prior art of simulating different grounding scenarios through resistance, this device achieves accurate simulation of different grounding fault types such as grounding faults.

[0010] The technical solution adopted by this utility model to solve its technical problem is as follows: The single-phase grounding test device based on 10kV overhead line of distribution network includes a main controller, a fault type switching module and a grounding mode selection module. The output terminal of the main controller is connected to the fault type switching module and the grounding mode selection module respectively. The fault type switching module is equipped with a switching switch, which connects to multiple different actual grounding scenarios. The 10kV overhead line is grounded to one of the actual grounding scenarios through the switching switch.

[0011] Preferred actual grounding scenarios include grasslands, bushes, and concrete surfaces.

[0012] Preferably, the grounding method selection module includes a switching switch, and the 10kV overhead line is connected to any one of the following systems through the switching switch in the grounding method selection module: ungrounded system, low-resistance grounding system, direct grounding system, arc suppression coil grounding system, and flexible grounding system.

[0013] Preferably, a human-machine interface is provided, which is connected to the main controller via wireless communication.

[0014] Preferably, a disconnecting switch is provided, with one end of the contacts of the disconnecting switch connected to the three phase lines of the 10kV overhead line, one end of the contacts of the disconnecting switch connected to the fault type switching module, and the signal output terminal of the main controller connected to the control terminal of the disconnecting switch.

[0015] Preferably, a grounding angle control module is provided, which is connected between the disconnecting switch and the fault type switching module, and the signal output terminal of the main controller is connected to the control terminal of the grounding angle control module.

[0016] Preferably, a data acquisition module is provided, with the input end of the data acquisition module connected to the output end of the disconnect switch and the output end of the data acquisition module connected to the main controller.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] In this single-phase grounding test device based on a 10kV overhead line in a power distribution network, the 10kV overhead line is connected to the actual grounding scenario through a switching switch in the fault type switching module. Compared with the existing technology that uses resistors to simulate different grounding scenarios, this device achieves accurate simulation of different grounding fault types such as grounding faults, improves the flexibility of grounding method selection, and can meet the test requirements in complex scenarios.

[0019] In this single-phase grounding test device based on a 10kV overhead line in a power distribution network,

[0020] In this single-phase grounding test device based on a 10kV overhead line in a power distribution network, the main controller connects to the human-machine interface via wireless communication, ensuring the safety of the operators.

[0021] By setting a grounding angle control module, operators can preset the grounding phase angle, and the device will automatically adjust the grounding angle to ensure the accuracy of the test.

[0022] By setting up a data acquisition module, key electrical parameters such as current and voltage can be monitored in real time during the test. If overcurrent, overvoltage or other abnormalities are detected, the overhead line can be disconnected through a disconnecting switch, effectively preventing accidents and ensuring the safety of the test process. Attached Figure Description

[0023] Figure 1 This is a block diagram of the principle of a single-phase grounding test device based on a 10kV overhead line in a power distribution network.

[0024] Figure 2 This is a circuit diagram of a single-phase grounding test device based on a 10kV overhead line in a power distribution network.

[0025] Figure 3 This is a circuit diagram of a single-phase grounding test device based on a 10kV overhead line in a power distribution network. Detailed Implementation

[0026] Figures 1-3 This is the preferred embodiment of the present invention, which is described below in conjunction with the appendix. Figures 1-3 The present invention will be further described below.

[0027] Example 1:

[0028] like Figure 1As shown, a single-phase grounding test device based on a 10kV overhead line of a power distribution network includes a human-machine interface and a main controller that is wirelessly connected to the human-machine interface. The communication between the human-machine interface and the main controller is achieved using wireless communication methods known in the art, such as Bluetooth and Wi-Fi.

[0029] The main controller's signal output terminal is connected to a grounding mode selection module, a disconnecting switch, a data acquisition module, a grounding angle control module, and a fault type switching module. The disconnecting switch is connected to a 10kV overhead line. The grounding angle control module and the fault type switching module are connected sequentially to the disconnecting switch's output terminal, with the output terminal of the fault type switching module grounded. The grounding mode selection module is also connected to the 10kV overhead line.

[0030] The main controller's signal output is simultaneously connected to the control signal inputs of the disconnect switch, grounding mode selection module, grounding angle control module, and fault type switching module. The main controller controls the operation of these modules respectively. A data acquisition module is also included; its input is connected to the output of the disconnect switch, and its output is connected to the main controller's signal input.

[0031] Combination Figure 2 The A, B, and C phase lines of the 10kV overhead line are connected to module U2 via grounding transformer U1. Module U2 is the grounding mode selection module mentioned above. The main controller U5 is connected to the grounding mode selection module. Module U7 is the disconnecting switch mentioned above. The disconnecting switch includes contactor KM1. One end of the normally open contacts KM1-1 to KM1-3 of contactor KM1 is connected to the A, B, and C phase lines of the 10kV overhead line, respectively. The other end of the normally open contacts KM1-1 to KM1-3 is connected to module U3. The control signal output terminal of controller U5 is connected to the coil of contactor KM1. Controller U5 is the main controller mentioned above. Controller U5 controls the coil of contactor KM1, and controls the on / off state of normally open contacts KM1-1 to KM1-3 by controlling the opening and closing of the coil of contactor KM1.

[0032] Module U3 is the aforementioned grounding angle control module. Module U3 includes contactor KM2, with the other ends of normally open contacts KM1-1~KM1-3 simultaneously connected to one end of normally open contact KM2-1 of contactor KM2. The other end of normally open contact KM2-1 is connected to module U4. The control signal output terminal of controller U5 is connected to the coil of contactor KM2. Controller U5 controls the coil of contactor KM2, and by controlling the on / off state of the normally open contact KM2-1, the on / off state of the normally open contact KM2-1 is controlled.

[0033] Module U4 is the aforementioned fault type switching module. In this embodiment, the fault type switching module is equipped with multiple switching switches. One end of each switching switch is connected to the output terminal of the grounding angle control module, and the other end of each switching switch is connected to an actual scenario, including dry ground, wet ground, cement ground, grassland, and shrubland scenarios. When simulating grounding faults in dry ground, grounding faults in dry soil environments can be simulated, and the impact of changes in grounding resistance on fault characteristics can be studied. When simulating grounding faults in wet ground, grounding faults in moist soil environments can be simulated, and the impact of humidity on fault current and voltage can be analyzed. When simulating grounding faults in cement environments, the impact of cement on fault current and voltage can be analyzed. When simulating grounding faults in grassland environments, the impact of vegetation on fault paths and grounding resistance can be studied. When simulating grounding faults in shrubland environments, the impact of vegetation density and grounding distance on fault characteristics can be analyzed. Therefore, accurate simulation of different grounding fault types, including grounding faults, is achieved through actual scenarios. Operators can select different fault types through the operating interface, and the device will automatically adjust the corresponding parameters and environmental conditions.

[0034] The control switch can be implemented using contactors. The signal output terminal of the main controller is connected to the coil of each contactor (through a known drive circuit) to control each contactor. The number of contactors corresponds one-to-one with the actual scenario. One end of the normally open contact of the contactor is connected to the output terminal of the grounding angle control module, and the other end of the normally open contact is connected to the corresponding actual scenario.

[0035] Combination Figure 3 The aforementioned grounding method selection module also includes a switch. The main controller is connected to the coil of the switch to control the operation of the switch. It also has five contacts corresponding to the switch. The switch is connected to one of the contacts. The other end of the five contacts is connected to five branches: branches L1 to L5. Branches L1 to L5 are respectively connected to an ungrounded system, a low-resistance grounding system, a direct grounding system, an arc suppression coil grounding system, and a flexible grounding system. The low-resistance grounding system, the direct grounding system, the arc suppression coil grounding system, and the flexible grounding system adopt circuit structures known in the art and are grounded.

[0036] The switching switch in the grounding method selection module can also be implemented directly using contactors. That is, five contactors are set up, each corresponding to branch L1 to L5. One end of branch L1 to L5 is connected to the normally open contact of each corresponding contactor. The signal output terminal of the main controller is connected to the coil of each contactor to realize the control of each contactor.

[0037] The specific working process and working principle are as follows:

[0038] Before conducting the test, the relevant test parameters are set through the human-machine interface, including: grounding method, grounding angle, and fault type. Then, the main controller controls the corresponding switching switches (contactors) in the grounding method selection module and the fault type switching module to select the grounding method and fault type.

[0039] After the test begins, the main controller determines the closing angle based on the voltage signal collected by the voltage transformer. When the preset angle is reached, the main controller controls the contactor KM2 in the grounding angle control module to operate, connecting this 10kV overhead line single-phase grounding test device to the 10kV overhead line, and testing the smart terminal based on the operation of the smart terminal installed in the 10kV overhead line.

[0040] During the test, when the main controller determines that the voltage in the line exceeds the threshold based on the data collected by the voltage transformer, it controls the isolating switch to open, thus providing protection. Furthermore, because the main controller and the human-machine interface are wirelessly connected, the personal safety of the operators is further ensured.

[0041] Example 2:

[0042] The difference between this embodiment and Embodiment 1 lies in the implementation method of the fault type switching module. In this embodiment, multiple resistors with different resistance values ​​are used to simulate fault types. Specifically, the fault type switching module includes multiple resistors with different resistance values ​​and multiple control switches corresponding to each resistor. One end of each resistor is connected to a contact of its corresponding control switch, and the other end is grounded. The main controller controls one of the control switches to connect the corresponding resistor to the line, thereby further realizing the accurate simulation of various different grounding fault types.

[0043] The control switch can be implemented using contactors. One end of the resistor is connected to one end of the normally open contact of its corresponding contactor, and the other end of the resistor is grounded. The signal output terminals of the main controller are connected to the coil of each contactor to control each contactor.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from its technical solution shall still fall within the protection scope of this utility model.

Claims

1. A single-phase grounding test device based on a power distribution network 10kV overhead line, comprising a main controller, a fault type switching module and a grounding mode selection module, the output of the main controller is connected with the fault type switching module and the grounding mode selection module respectively, characterized in that: the main controller is connected with a single-phase grounding test device, the single-phase grounding test device is connected with a 10kV overhead line, the fault type switching module is connected with a fault type switching device, and the grounding mode selection module is connected with a grounding mode selection device. The switching module is provided with a switching switch, the switching switch is connected with multiple different actual grounding scenes, and the 10kV overhead line is grounded through the switching switch and one of the actual grounding scenes.

2. The 10 kV overhead line single-phase grounding test device based on a power distribution network according to claim 1, characterized in that: The actual grounding scenes include grassland, shrubs and cement ground.

3. The 10 kV overhead line single-phase grounding test device based on a power distribution network according to claim 1, characterized in that: The grounding mode selection module includes a switching switch, and the 10kV overhead line is connected with any one of an ungrounded system, a small-resistance grounding system, a direct grounding system, an arc suppression coil grounding system and a flexible grounding system through the switching switch in the grounding mode selection module.

4. The 10 kV overhead line single-phase grounding test device based on power distribution network according to claim 1, characterized in that: A man-machine interface is arranged, and the man-machine interface is connected with the main controller in a wireless communication mode.

5. The 10 kV overhead line single-phase grounding test device based on power distribution network according to claim 1, characterized in that: A disconnector is arranged, one end of a contact in the disconnector is connected with three-phase lines of the 10kV overhead line, one end of the contact in the disconnector is connected with the switching module, and a signal output end of the main controller is connected with a control end of the disconnector.

6. The 10 kV overhead line single-phase grounding test device based on power distribution network according to claim 5, characterized in that: A grounding angle control module is arranged, the grounding angle control module is connected between the disconnector and the switching module, and a signal output end of the main controller is connected with a control end of the grounding angle control module.

7. The 10 kV overhead line single-phase grounding test device based on power distribution network according to claim 5, characterized in that: A data acquisition module is arranged, an input end of the data acquisition module is connected with an outgoing line end of the disconnector, and an output end of the data acquisition module is connected with the main controller.

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