Substation 10kV system single-phase grounding monitoring alarm and area judgment device and method

Abstract

The single-phase grounding monitoring alarm and area judgment device of the 10kV system of the substation includes a step voltage acquisition grounding terminal, a voltage acquisition module, an MCU, a voltage display module, an audible and visual alarm module, an access control module, a human-computer interaction module, an information sending module, and a power supply module; the method of the single-phase grounding monitoring alarm and area judgment device of the 10kV system in the substation, when a line of the 10kV system is single-phase grounded, the dispatcher will perform line selection processing, and after determining the grounding line, the line patrol personnel will be notified to patrol the line for processing. The advantages of the present invention are: it can give early warnings for grounding during daily patrols of operation and maintenance personnel, avoid single-phase grounding during substation patrols, enter the grounding area without knowing it, generate step voltage and contact the equipment casing to cause the risk of electric shock; at the same time, through the use of the device, it can realize rapid and accurate judgment of the grounding situation inside the substation and can judge the grounding area, thereby improving the efficiency of investigation.

Description

Technical Field

[0001] The present invention relates to the field of power systems, and in particular to a device and method for monitoring and alarming single-phase grounding and determining an area of ​​a 10kV system in a substation. Background Art

[0002] When a 10kV system is single-phase grounded, the regional dispatcher will select the grounding line, and after determining the grounding line, notify the line patrol personnel to patrol the line and handle it, and notify the operation and maintenance personnel to go to the substation to check whether the line is abnormal. If the grounding line is not determined, the dispatcher notifies the operation and maintenance personnel to conduct a grounding inspection in the station. The inspection range is from the secondary bushing of the transformer to the 10kV line outlet. The investigation process to determine the grounding point is time-consuming, and even if the operating personnel have taken protective measures, it is easy to enter the 4-meter range of the grounding point during on-site inspections, which may cause electric shock hazards due to step voltage or contact with the casing of high-voltage equipment. When the operation and maintenance personnel conduct daily inspections, they do not need to wear insulating boots and insulating gloves. If they happen to encounter a single-phase grounding in the high-voltage room of a substation, it is very dangerous for the patrol personnel. Summary of the invention

[0003] The purpose of the present invention is to avoid the risk of electric shock caused by operating personnel entering a high-voltage room with single-phase grounding without knowing it during daily inspections, and to avoid blindly entering the high-voltage room to check the grounding point, which is time-consuming and dangerous. There is an urgent need for a device that can automatically monitor the single-phase grounding situation in the high-voltage room in real time and can determine the grounding area to ensure the personal safety of personnel and improve the efficiency of investigation. A single-phase grounding monitoring alarm and area judgment device and method for a 10kV system in a substation are provided.

[0004] The present invention provides a substation 10kV system single-phase grounding monitoring alarm and area judgment device, which is characterized in that: the substation 10kV system single-phase grounding monitoring alarm and area judgment device comprises a step voltage acquisition grounding terminal, a voltage acquisition module, an MCU, a voltage display module, an audible and visual alarm module, an access control module, a human-computer interaction module, an information sending module, and a power supply module;

[0005] The step voltage collection grounding terminal is set under the cable trench cover plate on both sides of the high-voltage room switch cabinet and close to the ground surface; every two grounding terminals form a group. When single-phase grounding occurs in the high-voltage room, the potential difference between the two grounding terminals is converted into the step voltage of the group after conversion. Multiple groups of grounding terminals are set as needed. The grounding terminals are connected to the voltage collection module through cables, and connected to the MCU through the voltage collection module; the voltage collection module is a multi-channel voltage and current collection module, which transmits the collected voltage to the MCU; the voltage display module is a serial port LCD screen, which is used to display each group of step voltage values, grounding prediction areas, main alarm information of the background monitoring system in the station, view historical data, and modify set parameters;

[0006] The sound and light alarm module includes voice broadcast function, running light and warning light.

[0007] The access control module is used to lock the high voltage room door when a ground alarm occurs.

[0008] The information sending module is used to inform the operator of the alarm information as soon as possible when the device alarms.

[0009] The voltage display module, the sound and light alarm module, the access control module, the human-computer interaction module and the information sending module are all connected to the MCU, which is a single-chip microcomputer.

[0010] The power module provides working power for the device; except for the step voltage acquisition ground terminal, other modules are integrated on the host outside the high-voltage room door.

[0011] A method for monitoring and alarming single-phase grounding of a 10kV system in a substation and a regional judgment device. When a line of a 10kV system is single-phase grounded, the background monitoring host in the station will display the 3U0 over-limit alarm of the 10kV bus PT, and the bus voltage will increase in two phases and decrease in one phase. The dispatcher will select the line, and after determining the grounded line, notify the line patrol personnel to patrol the line, and notify the operation and maintenance personnel to go to the substation to check whether the line is abnormal; if the grounding point is the grounding on the outgoing line side of the line in the station, the alarm device will send an alarm message to the monitoring host in the station and send a text message alarm to the operation and maintenance personnel, reducing the unnecessary workload of the line patrol personnel.

[0012] If the dispatcher fails to identify the grounding line and suspects that there is grounding inside the station, he will notify the operation and maintenance personnel to conduct an inspection inside the station; when the step voltage inside the high-voltage room of the substation exceeds the limit and the alarm sounds, it can be determined that there is grounding inside the high-voltage room of the substation. The LCD screen displays the step voltage value of each grounding end. The size of the step voltage value at several locations can be preliminarily determined that there is grounding somewhere on the I or II bus in the high-voltage room. The alarm information will be received by the dispatcher and operation personnel as soon as possible.

[0013] If the dispatcher fails to identify the grounding line and suspects grounding inside the station, and if the step voltage in the high-voltage room does not exceed the limit alarm, the grounding point may be between the secondary bushing of the main transformer outside the high-voltage room and the busbar in the station, which can narrow the inspection scope and improve the efficiency of investigation. When a grounding alarm occurs, the sound and light alarm module will send out a sound and light alarm to remind the operating personnel to take protective measures. When a grounding alarm occurs, the information sending module will send a text message reminder to the operating personnel, so that they can understand the situation on site in time and take protective measures.

[0014] When the grounding alarm occurs, the host controls the high-voltage room door to be locked. If you need to enter, you can unlock it with a manual password and open the high-voltage room door. Personal protective measures are taken to ensure the personal safety of operation and maintenance personnel.

[0015] Advantages of the present invention:

[0016] It can provide early warning for operation and maintenance personnel when grounding occurs during their daily inspections, avoiding single-phase grounding during substation inspections, and entering the grounding area without knowing it, which can cause the risk of step voltage and electric shock caused by contact with the equipment casing. At the same time, through the use of this device, it can quickly and accurately determine the grounding situation inside the substation and the grounding area, thereby improving the efficiency of investigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0018] Figure 1 Principle structure diagram of the single-phase grounding monitoring alarm and area judgment device of the substation 10kV system;

[0019] Figure 2 Distribution diagram of high voltage indoor grounding terminals;

[0020] Figure 3 Host structure diagram;

[0021] Figure 4 Flowchart of the single-phase grounding monitoring alarm and area judgment method for the 10kV system in the substation. DETAILED DESCRIPTION

[0022] Example

[0023] according to Figure 1 As shown, the present invention provides a method and device for monitoring and warning single-phase grounding and determining the area of ​​a 10kV system in a substation. The device can effectively solve the problem that the operating personnel may enter the high-voltage room with single-phase grounding without knowing it during daily inspections, which may cause electric shock, and the problem that it is time-consuming and dangerous to blindly enter the high-voltage room to check the grounding point.

[0024] Figure 1 The middle ground terminal 1 is connected to the voltage acquisition module 2, and the voltage acquisition module 2 transmits the step voltage to the MCU 3; the MCU 3 is also connected to the voltage display module 4, the sound and light alarm module 5, the access control module 6, the information sending module 7, the human-computer interaction module 8 and the background monitoring system 10;

[0025] Figure 2 The distribution diagram of the grounding terminal in the high-voltage room is shown in the figure. The present invention sets the grounding terminal 1 under the cable trench cover plate on both sides of the front and rear sides of the high-voltage room I and II female switch cabinets, and as close to the ground surface as possible. The grounding terminal can be replaced by a copper bar or a copper column; every two grounding terminals form a group. When a single-phase grounding occurs in the high-voltage room, the potential difference between the two grounding terminals is converted into the step voltage of the group after conversion. N groups of grounding terminals can be set as needed. The grounding terminal 1 is connected to the voltage acquisition module 2 through a cable, and is transmitted to the MCU3 through the voltage acquisition module 2;

[0026] Assume that the distance between the i-th group of ground terminals is Li, the potential difference is ULi, and the step voltage UKi of this group is 0.7*ULi / Li.

[0027] Voltage acquisition module 2 is a multi-channel voltage and current acquisition module, which transmits the collected ground terminal potential difference ULi to MCU3;

[0028] MCU3 is a single chip microcomputer, which can convert ULi into step voltage UKi, and exchange information with the substation background monitoring system 10, and then make a prediction on the grounding condition of the substation.

[0029] The voltage display module 4 is a serial port LCD screen, which is used to display each group of step voltage values, grounding prediction area, main alarm information of the station monitoring host, view historical data and modify setting parameters, etc.;

[0030] The sound and light alarm module 5 includes a voice broadcast function, an operating light and a warning light; when the device alarms, it can issue "single-phase grounding occurs in the system, enter with caution, and take precautions", etc., and can record the alarm voice as needed; when there is no alarm, the operating light is always green and the warning light is always off; when there is an alarm, the warning light flashes red and the operating light is always off;

[0031] The access control module 6 is used to lock the high-voltage room door when a ground alarm occurs, prohibiting personnel from entering the high-voltage room without taking protective measures;

[0032] The information sending module 7 can be a 4G communication module, which can send the alarm information to the operator and other relevant personnel in a timely manner in the form of text messages;

[0033] The human-computer interaction module 8 can be a matrix digital embedded keyboard, which can be used for parameter setting, password input, historical data viewing, updating the operator's mobile phone number, etc.;

[0034] When the grounding alarm door is locked, if you need to enter, you can manually enter the password through the human-computer interaction module 8 to unlock it, thereby ensuring that personnel open the high-voltage room door calmly and with safety protection in place, ensuring the personal safety of operation and maintenance personnel.

[0035] The power module 9 provides working power for the device;

[0036] Except for the step voltage acquisition ground terminal 1, other modules are integrated on the host outside the high voltage room door. The host structure diagram is as follows Figure 3 As shown;

[0037] When one of the following conditions is met on site, the device will issue an alarm action:

[0038] Case 1: The substation backend monitoring system 10 shows an over-limit alarm for the 10kV busbar PT. The busbar voltage increases in two phases and decreases in one phase, but the step voltage in the station does not exceed the limit alarm.

[0039] Case 2: The substation backend monitoring system 10 displays an over-limit alarm for the 10kV busbar PT of the substation. The busbar voltage increases in two phases and decreases in one phase. At the same time, an over-limit alarm is issued for the step voltage in the station.

[0040] Case 3: The substation backend monitoring system 10 has no single-phase grounding alarm, but the step voltage in the station exceeds the limit alarm. This situation may exist when there is an abnormality in the device itself;

[0041] The specific use process of the present invention includes but is not limited to the following four situations:

[0042] Situation (1) Most substations are unmanned. When the operation and maintenance personnel do daily inspections, they do not need to wear insulating boots and insulating gloves. If they happen to encounter a single-phase grounding in the high-voltage room of a substation, it is very dangerous for the inspectors. The use of this device can prevent the operating personnel from entering the grounding area without knowing it and causing the risk of electric shock;

[0043] Case (2) A line in the 10kV system is single-phase grounded, and the grounding point is on the line outside the substation. The substation background monitoring system 10 displays an over-limit alarm for the 10kV bus PT, and an alarm signal that the bus voltage increases in two phases and decreases in one phase. The dispatcher will select the line and notify the line patrol personnel to patrol and handle it after determining the grounded line. At the same time, the operation and maintenance personnel will be notified to go to the substation to check whether there is any abnormality in the line. At this time, the step voltage in the high-voltage room in the station has not reached the alarm value, but the substation background monitoring system 10 will send an alarm message to MCU3, causing the device to alarm. At the same time, the device will send a text message alarm to the operation and maintenance personnel: "The line is single-phase grounded, and the line grounding point may be outside the station."

[0044] Case (3) A line in the 10kV system is single-phase grounded, and the grounding point is on the line side of the high-voltage room in the substation. The substation background monitoring system 10 will display the over-limit alarm of the 10kV bus PT, and the alarm signal of the bus voltage rising in two phases and falling in one phase. The dispatcher will select the line and notify the line patrol personnel to patrol and handle it after determining the grounded line. At the same time, the operation and maintenance personnel will be notified to go to the substation to check whether there is any abnormality in the line. The step voltage in the high-voltage room in the station may exceed the limit. The device will alarm, send an alarm message to the substation background monitoring system 10 and send a text message alarm to the operation and maintenance personnel: "The line is single-phase grounded, and the grounding point may be on the line outlet side of the high-voltage room in the station", thereby reducing the unnecessary workload of the line patrol personnel.

[0045] Case (4) 10kV system single-phase grounding, the grounding point is between the secondary bushing of the main transformer and the busbar in the substation. The substation monitoring system 10 will display the over-limit alarm of the 10kV busbar PT, and the alarm signal of the busbar voltage rising in two phases and falling in one phase. The dispatcher failed to identify the grounding line and suspected that it was grounded in the station. The operation and maintenance personnel will be notified to conduct an inspection in the station. When the step voltage in the high-voltage room of the substation exceeds the limit alarm, it can be judged as grounding in the substation. The voltage display module 4 displays the step voltage value of each grounding terminal 1. Through the size of the step voltage value at several locations, it can be preliminarily judged that it is near the i-th grounding terminal of the I mother or II mother in the high-voltage room. The operating personnel will receive the message "grounding near the i-th grounding terminal of the I mother or II mother in the high-voltage room"; if the step voltage in the high-voltage room of the substation does not exceed the limit, the substation background monitoring system 10 will send an alarm message to MCU3, so that the device still alarms and sends an alarm message: "The grounding point may be between the secondary bushing of the outdoor main transformer and the busbar", which greatly reduces the inspection scope and improves the efficiency of troubleshooting. Figure 4 This is a flow chart of the single-phase grounding monitoring alarm and area judgment method for the substation 10kV system.

[0046] When the device is activated and the alarm is sounded, the voltage display module 4 will display the step voltage value at each grounding terminal 1, as well as the predicted grounding point position. The information sending module 7 will send a corresponding alarm text message to the operating personnel, and the sound and light alarm module 5 will be activated, the alarm light will flash red, the operating light will be off and the message "Single-phase grounding has occurred in the system, enter with caution and take precautions" will be issued. At the same time, the access control module will be activated to control the locking of the high-voltage room door. If you need to enter, you can manually enter the password through the human-computer interaction module 8 to unlock it, thereby ensuring that personnel open the high-voltage room door calmly and with safety protection in place, thereby ensuring the personal safety of the operation and maintenance personnel.

[0047] The device can provide early warning for grounding during routine inspections by operation and maintenance personnel, avoiding single-phase grounding during substation inspections and the risk of entering the grounding area without knowing it, generating step voltage and contacting the equipment casing to cause electric shock. At the same time, through the use of this device, it is possible to quickly and accurately determine the grounding conditions inside the substation and the grounding area, thereby improving the efficiency of investigation.

Claims

1. A method for using a 10kV system single-phase grounding monitoring alarm and area judgment device in a substation, characterized in that: The substation 10kV system single-phase grounding monitoring alarm and area judgment device comprises a step voltage acquisition grounding terminal, a voltage acquisition module, an MCU, a voltage display module, an audible and visual alarm module, an access control module, a human-computer interaction module, an information sending module, and a power supply module; The step voltage collection grounding terminal is set under the cable trench cover plate on both sides of the high-voltage room switch cabinet and close to the ground surface; every two grounding terminals form a group. When single-phase grounding occurs in the high-voltage room, the potential difference between the two grounding terminals is converted into the step voltage of the group after conversion. Multiple groups of grounding terminals are set as needed. The grounding terminals are connected to the voltage collection module through cables, and connected to the MCU through the voltage collection module; the voltage collection module is a multi-channel voltage and current collection module, which transmits the collected voltage to the MCU; the voltage display module is a serial port LCD screen, which is used to display each group of step voltage values, grounding prediction areas, main alarm information of the background monitoring system in the station, view historical data and modify setting parameters; the sound and light alarm module includes voice broadcast function, operation light and warning light; the access control module is used to lock the high-voltage room door when a grounding alarm occurs; the information sending module is used to tell the operating personnel the alarm information as soon as possible when the device alarms; the voltage display module, the sound and light alarm module, the access control module, the human-computer interaction module and the information sending module are all connected to the MCU, which is a single-chip microcomputer; The power module provides working power for the device; except for the step voltage acquisition grounding terminal, other modules are integrated on the host outside the high-voltage room door; Usage: When a line of the 10kV system is single-phase grounded, the background monitoring host in the station will display the 3U0 over-limit alarm of the 10kV bus PT, and the bus voltage will increase in two phases and decrease in one phase; the dispatcher will select the line, and after determining the grounding line, notify the line patrol personnel to patrol the line, and notify the operation and maintenance personnel to go to the substation to check whether there is any abnormality in the line; if the grounding point is the grounding on the outgoing line side of the line in the station, the information sending module will send an alarm message to the monitoring host in the station and send a text message alarm to the operation and maintenance personnel, reducing the unnecessary workload of the line patrol personnel; if the dispatcher fails to determine the grounding line and suspects that it is grounded in the station, at the same time, when the step voltage in the high-voltage room of the substation exceeds the limit alarm, it can be judged that the high-voltage room of the substation is grounded, and the liquid The crystal screen displays the step voltage value of each grounding end. Through the size of the step voltage value at several positions, it can be preliminarily judged that there is grounding somewhere in the I mother or II mother of the high-voltage room, and the alarm information will be received by the dispatcher and operation personnel at the first time; if the dispatcher fails to determine the grounding line, it is suspected that it is grounded in the station. At the same time, the step voltage in the high-voltage room has not exceeded the limit alarm. The grounding point is between the secondary bushing of the main transformer outside the high-voltage room in the station and the busbar, which can narrow the inspection scope and improve the efficiency of investigation; when the grounding alarm occurs, the sound and light alarm module will send out a sound and light alarm to remind the operation personnel to take protective measures; when the grounding alarm occurs, the information sending module will send a text message reminder to the operation personnel, so as to understand the on-site situation in time and take protective measures; when the grounding alarm occurs, the host controls the high-voltage room door to be locked. If you need to enter, you can unlock it with a manual password, open the high-voltage room door, and take personal protective measures to ensure the personal safety of the operation and maintenance personnel.

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