Ground fault protection device suitable for 6kV power supply system in mining area

Abstract

The utility model discloses a ground fault protection device suitable for a mining area 6kV power supply system, and belongs to the technical field of mining area power supply system ground fault protection. Which comprises a sensor installed in a line, an opening and closing switch and a protection terminal device, and is characterized by further comprising an opening and closing control unit, the input and output end of a main control unit is in bidirectional connection with the input and output end of an auxiliary controller, and the output end of the auxiliary controller is connected with the input end of an execution module; the execution module is connected with the opening and closing switch, the opening and closing switch is further connected with the signal receiving module, and the signal output end of the signal receiving module is connected with the auxiliary controller. According to the grounding fault protection device suitable for the 6kV power supply system in the mining area, the opening and closing control unit is arranged, the auxiliary controller in the opening and closing control unit is used for controlling the opening and closing switch to act, the operation pressure of the main control unit is reduced, and meanwhile the switching state of the opening and closing switch is fed back through the signal receiving module; and the reliability of opening and closing is improved.

Description

Technical Field

[0001] A grounding fault protection device applicable to a 6kV power supply system in a mining area belongs to the technical field of grounding fault protection for power supply systems in mining areas. Background Art

[0002] As an important industrial power infrastructure, the stable operation of the power supply system in a mining area is crucial for the production safety and economic benefits of the mining area. To meet the power consumption needs of high-power equipment, the 6kV voltage level is usually adopted in the power supply system of the mining area. More and more distributed power sources such as wind power and photovoltaic power generation are introduced into the power supply system to reduce the dependence on traditional thermal power generation and improve energy utilization efficiency. This also makes the power supply system more complex and more difficult to maintain. To ensure the safe operation of the system and reduce the power outage time after a grounding fault occurs in the line, it is very important to accurately locate and isolate the fault location in a timely manner.

[0003] The grounding fault protection in traditional mining area power supply systems mainly targets centralized power supply systems, and its protection strategies and equipment configurations cannot effectively handle the grounding fault problems generated when distributed power sources are connected. These faults include increased grounding resistance, short circuit of grounding lines, etc., which may cause partial or complete shutdown of the power supply system in severe cases. In the prior art, some technical solutions for grounding faults in power supply systems are also recorded, such as the technical solution disclosed in the Chinese utility model patent with the application number 200420093823.5, the application date of October 10, 2004, and the patent name of "A new type of grounding fault detection device for distribution network", and the technical solution disclosed in the Chinese invention patent with the application number 201310753603.4, the application date of December 31, 2013, and the patent name of "Overvoltage suppression and fault location isolation control device for distribution network".

[0004] However, the prior art including the above technical solutions is difficult to be directly applied to the grounding fault detection and treatment of the mining area power supply system. The reasons are as follows: there is a problem of insufficient complex grounding fault handling ability in modern mining area power supply systems. In traditional technical solutions for grounding fault handling, only the main controller is used for processing, so the processing load of the controller is relatively large. At the same time, in the existing technical solutions, the grounding fault protection mechanism and equipment configuration fail to effectively handle the complex grounding problems brought about by the access of distributed power sources. And the switch states in the line are not fed back to the controller, so there is also a problem that reliable switching on and off are difficult to achieve. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a grounding fault protection device applicable to the 6kV power supply system in mining areas. By setting a closing and opening control unit and using the sub-controller in the closing and opening control unit to control the closing and opening switch to act, the operating pressure of the main control unit is reduced. At the same time, the switch state of the closing and opening switch is fed back through the signal receiving module, improving the reliability of closing and opening.

[0006] The technical solution adopted by the utility model to solve its technical problems is as follows: The grounding fault protection device applicable to the 6kV power supply system in mining areas includes a sensor installed in the line and a closing and opening switch, and a protection terminal device is also provided. The protection terminal device includes a main control unit. The sensor is connected to the main control unit, and the main control unit is connected to the closing and opening switch. It is characterized in that the protection terminal device further includes a closing and opening control unit. The main control unit is bidirectionally connected to the closing and opening control unit, and the closing and opening control unit is connected to the closing and opening switch.

[0007] The closing and opening switch includes a sub-controller, an execution module, and a signal receiving module. The input and output ends of the main control unit are bidirectionally connected to the input and output ends of the sub-controller. The output end of the sub-controller is connected to the input end of the execution module. The execution module is connected to the closing and opening switch. The closing and opening switch is also connected to the signal receiving module. The signal output end of the signal receiving module is connected to the sub-controller.

[0008] Preferably, the protection terminal device further includes an analog quantity acquisition unit. The signal output end of the sensor is connected to the input end of the analog quantity acquisition unit, and the output end of the analog quantity acquisition unit is connected to the main control unit.

[0009] Preferably, the analog quantity acquisition unit includes an analog-to-digital conversion module and a comparator module. The signal output end of the sensor is connected to the input end of the analog-to-digital conversion module, and the output end of the analog-to-digital conversion module is connected to the main control unit.

[0010] Preferably, the main control unit includes a main controller and a band-pass filter. The output end of the analog quantity acquisition unit is connected to the input end of the band-pass filter, and the output end of the band-pass filter is connected to the input end of the main controller. The main controller is bidirectionally connected to the closing and opening control unit.

[0011] Preferably, the protection terminal device further includes a communication unit. The main control unit is bidirectionally connected to the communication unit, and the communication unit is bidirectionally connected to the main station.

[0012] Preferably, the protection terminal device further includes a storage unit. The main control unit is connected to the storage unit.

[0013] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0014] In the grounding fault protection device applicable to the 6kV power supply system in mining areas, by setting up a switching control unit and using the sub-controller in the switching control unit to control the switching operation, the operating pressure on the main control unit is reduced. At the same time, the switching state of the switching is fed back through the signal receiving module, improving the reliability of switching.

[0015] In the grounding fault protection device applicable to the 6kV power supply system in mining areas, through real-time monitoring and rapid fault identification operations, the fault section can be located and isolated within the shortest time, reducing the damage to power equipment caused by faults and ensuring the stable operation of equipment to the greatest extent. By implementing a multi-level protection strategy and intelligent control, the device can have the ability to adapt to complex mining area environments.

[0016] In the grounding fault protection device applicable to the 6kV power supply system in mining areas, the device is equipped with a communication unit, supporting remote monitoring and control, and capable of sending alarms and anomaly notifications in real time, enabling maintenance personnel to respond and handle problems quickly, reducing the fault handling time and maintenance costs.

[0017] The device parameters and device operation data are recorded through the storage unit, providing data support for fault diagnosis, performance evaluation, and system optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic block diagram of the principle of the grounding fault protection device applicable to the 6kV power supply system in mining areas.

[0019] Figure 2 It is a schematic block diagram of the principle of the protection terminal device of the grounding fault protection device applicable to the 6kV power supply system in mining areas.

[0020] Figure 3 It is a schematic block diagram of the principle of the analog quantity acquisition unit of the grounding fault protection device applicable to the 6kV power supply system in mining areas.

[0021] Figure 4 It is a schematic block diagram of the principle of the main control unit of the grounding fault protection device applicable to the 6kV power supply system in mining areas.

[0022] Figure 5 It is a schematic block diagram of the principle of the switching control unit of the grounding fault protection device applicable to the 6kV power supply system in mining areas. DETAILED DESCRIPTION OF THE INVENTION

[0023] Figures 1 - 5 This is the best embodiment of the present invention. The following further describes the present invention in conjunction with the attached Figures 1 - 5 drawings.

[0024] Such as Figure 1As shown in the figure, a ground fault protection device applicable to a 6kV power supply system in a mining area (hereinafter referred to as the protection device) includes a protection terminal device, which is connected to the master station and realizes two-way communication. The protection terminal device is connected to a switch for opening and closing, and the switch for opening and closing is installed on the overhead line of the distribution network. The protection terminal device controls the opening and closing state of the switch for opening and closing to disconnect or reclose the power line, so as to isolate the fault and restore power supply. An external sensor connected to the protection terminal device is also provided, and the external sensor is connected in the line for sending the collected data to the protection terminal device.

[0025] As Figure 2 shown, the protection terminal device includes an analog quantity acquisition unit, a main control unit, a storage unit, a communication unit, and a switch control unit for opening and closing. The external sensor is connected to the analog quantity acquisition unit, and the analog quantity acquisition unit is connected to the main control unit. The data collected by the external sensor is sent to the main control unit through the analog quantity acquisition unit. The external sensor includes common voltage sensors, current sensors, zero-sequence current transformers, and zero-sequence voltage transformers in the art. The three-phase voltage, three-phase current, zero-sequence current, and zero-sequence voltage in the line are respectively collected through the external sensor.

[0026] The output end of the main control unit is connected to the storage unit. At the same time, the input and output ports of the main control unit are respectively bidirectionally connected to the communication unit and the switch control unit for opening and closing. The main control unit communicates with the master station through the communication unit. At the same time, the main control unit is connected to the switch for opening and closing through the switch control unit for opening and closing. The main control unit controls the action of the switch for opening and closing through the switch control unit for opening and closing, and obtains the on-off state of the switch for opening and closing through the switch control switch.

[0027] As Figure 3 shown, the analog quantity acquisition unit includes an analog-to-digital conversion module and a comparator module, and the analog-to-digital conversion module and the comparator module are respectively implemented by commercially available common analog-to-digital conversion chips and comparator chips. The signal output end of the external sensor is connected to the input end of the analog-to-digital conversion module, and the analog-to-digital conversion is performed by the analog-to-digital conversion module. The output end of the analog-to-digital conversion module is connected to the comparator module, and the comparator module is used to compare the collected zero-sequence voltage or zero-sequence current with a set threshold. If the collected value exceeds the pre-reviewed threshold, the comparator module will send the data to the main control module to indicate that a ground fault has occurred in the line.

[0028] As Figure 4 shown, the main control unit includes a band-pass filter and a main controller. The output end of the comparator module is connected to the input end of the band-pass filter, and the output end of the band-pass filter is connected to the input end of the main controller. The main controller is respectively connected to the storage unit, the communication unit, and the switch control unit for opening and closing.

[0029] As Figure 5As shown in the figure, the closing and opening control unit includes a secondary controller, an execution module, and a signal receiving module. The main controller in the main control unit is bidirectionally connected to the secondary controller. The output end of the secondary controller is connected to the input end of the execution module. The output end of the execution module is connected to the closing and opening switch, and the closing and opening switch is also connected to the signal receiving module. The signal receiving module collects the switch state of the closing and opening switch and sends it to the secondary controller, and the secondary controller feeds back the on-off state of the closing and opening switch to the main control unit.

[0030] The specific working process and working principle are as follows:

[0031] The three-phase current, three-phase voltage, zero-sequence current, and zero-sequence voltage in the line are collected by an external sensor, and the data collected by the external sensor is sent to the analog quantity acquisition unit. After the data enters the analog quantity acquisition unit, it is first subjected to analog-to-digital conversion by the analog-to-digital conversion module, and then sent to the comparator module for threshold comparison. When the collected data is greater than the preset threshold, it indicates that a fault has occurred in the line, and the comparator module sends a signal to the main control unit.

[0032] After the signal output by the comparator module enters the main control unit, it is first filtered by a band-pass filter to extract the transient signal characteristics, and then the filtered signal is sent to the main controller, and the main controller judges the fault direction according to the transient signal characteristics.

[0033] The main controller starts the tripping delay program. During the tripping delay period, the fault state is continuously monitored. When the fault still has not disappeared when the tripping delay reaches the set value, the main controller sends a tripping instruction to the secondary controller in the closing and opening control unit. The secondary controller controls the closing and opening switch to perform the tripping action through the execution module. At the same time, the signal receiving module feeds back the on-off state of the closing and opening switch from the secondary controller to the main controller. The main controller receives the state data of the closing and opening switch changing from "closed" to "open" sent by the signal receiving module and determines that the tripping is successful. At this time, the fault is isolated.

[0034] After the tripping is successful, the main controller performs reclosing timing. After the reclosing delay arrives, a reclosing instruction is sent to the secondary controller, and the secondary controller controls the execution module to perform the reclosing action. Then the main control unit receives the state data of the closing and opening switch changing from "open" to "closed" sent by the signal receiving module and determines that the reclosing is successful;

[0035] If the main controller receives the fault occurrence message sent by the analog quantity acquisition unit again within 0.5 s after the reclosing, it immediately sends a second tripping instruction to the execution unit. The main control unit receives the data of changing from "closed" to "open" sent by the digital quantity unit signal receiving module and determines that the second tripping is successful, and the fault section is isolated again.

[0036] During the above-mentioned process of handling the current ground fault, the storage unit first records all the voltage and current waveform data collected by the analog quantity acquisition unit and the digital quantity acquisition unit, as well as the switch status information; for key information such as the transient signal characteristics before and after the fault, the fault direction judgment process, and the timestamps of tripping and reclosing, the storage unit makes a detailed record as the basis for subsequent fault analysis.

[0037] At the same time, the main control unit packs the zero-sequence voltage and zero-sequence current during the fault process, the corresponding judgment results and processing processes of the control unit, and the signal processing such as the change of the on-off switch status into the standard communication protocol format through the communication unit and transmits them to the master station.

[0038] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A grounding fault protection device applicable to a 6kV power supply system in a mining area, comprising sensors installed in a circuit and a switching-on and switching-off switch, and further provided with a protection terminal device. The protection terminal device includes a main control unit. The sensor is connected to the main control unit, and the main control unit is connected to the switching-on and switching-off switch. It is characterized in that: The protection terminal device further includes a closing and opening control unit. The main control unit is bidirectionally connected to the closing and opening control unit, and the closing and opening control unit is connected to the closing and opening switch. The closing and opening switch includes a sub-controller, an execution module, and a signal receiving module. The input and output ends of the main control unit are bidirectionally connected to the input and output ends of the sub-controller. The output end of the sub-controller is connected to the input end of the execution module. The execution module is connected to the closing and opening switch. The closing and opening switch is also connected to the signal receiving module. The signal output end of the signal receiving module is connected to the sub-controller.

2. The grounding fault protection device applicable to the 6kV power supply system in the mining area according to claim 1, characterized in that: The protection terminal device further includes an analog quantity acquisition unit. The signal output end of the sensor is connected to the input end of the analog quantity acquisition unit, and the output end of the analog quantity acquisition unit is connected to the main control unit.

3. The grounding fault protection device applicable to the 6kV power supply system in the mining area according to claim 2, characterized in that: The analog quantity acquisition unit includes an analog-to-digital conversion module and a comparator module. The signal output end of the sensor is connected to the input end of the analog-to-digital conversion module, and the output end of the analog-to-digital conversion module is connected to the main control unit.

4. The grounding fault protection device applicable to the 6kV power supply system in the mining area according to claim 2, wherein: The main control unit includes a main controller and a band-pass filter. The output end of the analog quantity acquisition unit is connected to the input end of the band-pass filter. The output end of the band-pass filter is connected to the input end of the main controller. The main controller is bidirectionally connected to the closing and opening control unit.

5. The grounding fault protection device applicable to the 6kV power supply system in the mining area according to claim 1, wherein: The protection terminal device further includes a communication unit. The main control unit is bidirectionally connected to the communication unit, and the communication unit is bidirectionally connected to the master station.

6. The grounding fault protection device applicable to the 6kV power supply system in the mining area according to claim 1, characterized in that: The protection terminal device further includes a storage unit. The main control unit is connected to the storage unit.

Images