Line grounding short circuit fault location system

1. Introduction
There are quite a few single-phase grounding faults in overhead transmission and distribution lines in our country. Once a grounding fault occurs, it is necessary to manually search along the line. In areas with complex geographical conditions, fault search is difficult and time-consuming. Therefore, it is necessary to use simple and low-cost modern technology to locate the grounding fault point.
The GZTC line grounding fault location system combines our company's years of experience in fault detection technology in power systems, advanced wireless transmission technology, and popular GPRS (or SMS) communication technology, and has the function of automatic grounding fault location. When a grounding fault occurs in the line, this system specifically locates the fault to a certain pole and quickly transmits the grounding information to the monitoring center, so that the staff can make timely handling of the fault.

2、 Scope of application
The GZTC type line grounding fault location system is suitable for power grids operating in various grounding modes, including:
1. Neutral point direct grounding system.
2. The neutral point is grounded through a resistor system.
3. Neutral point ungrounded system for 10kV and below.
4. Neutral point grounding system with arc suppression coil for 10kV and below.

3、 System composition and principle
This system mainly includes: acquisition terminal, monitoring center, and signal generation device.
1. Collection terminal
The device is mounted on the line, collects fault signals, and sends them to the monitoring center in the form of GPRS (or SMS).
2. Monitoring Center
Composed of information receiving devices and computers, the system is equipped with dedicated GZTC monitoring software. The information receiving device is connected to the computer through a communication interface. The fault information is transmitted to the computer through the GPRS (or SMS) module in the receiving device, and the computer analyzes and processes the received data. Display the fault route and location on a wiring diagram, sound an alarm to notify the duty personnel, and send an alarm SMS to the designated mobile phone.
3. Signal generating device
This device is applied to neutral point ungrounded systems of 10kV and below or systems grounded through arc suppression coils. The main function is to provide better criteria for the GZTC type line grounding fault location system.

4、 Introduction to the Monitoring Center System
The monitoring center system consists of software and hardware, mainly responsible for collecting, recording, and processing data transmitted back by the collection and transmission terminals, recording ground fault events, automatic alarms, and other work, including:
(1) Route map, establishment and modification of monitoring points
(2) Instantly display the current network status
(3) Status inquiry
(4) Display fault description information and alarm after the fault occurs.
(5) Self checking and other functions
Management personnel use microcomputers as operating terminals to understand fault status, perform data queries, and participate in troubleshooting at any time.
1. Monitoring and Management
The monitoring and management function interface is the permanent interface of this system, allowing operators to understand the operation status of the line through this interface, query terminal parameters, set terminal parameters, historical data, and real-time waveforms based on detection points. On the interface, there is a set of green icons corresponding to the position of each group of terminals. When clicking on the icon with the mouse, the specific information of the detection point will be displayed
2. Data analysis
The data analysis function is a tool used to process monitoring data. This function provides a complete set of convenient, concise, and intuitive means for operators to browse and process data. Firstly, upon entering the function interface, all data is arranged in chronological order from first to last. The operator can directly access the data at the corresponding time by inputting the time of submitting the "alarm".
3. System configuration
The function of system configuration is to achieve:
(1) Association configuration between installation location of information collection and transmission terminal and software system
(2) System user permission management and configuration of related information
(3) The phone number to send the alarm message
4. Historical event query
Event query can display all current and historical events, with the starting time indicating the time of the event occurrence, making it easy for users to check at any time.

5、 Technical parameters
1. Collection terminal
GPRS (or SMS) operating frequency: 900/1800MHz
Dimensions: 100 × 230 × 270
Environmental temperature: -30~70 ℃
Protection level: IP65
Equipment lifespan: 10 years
2. Monitoring Center
Temperature: 25 ± 5 degrees Celsius
Humidity: 20% to 80%
Data Structure: Using SQL Server Database
Communication protocol: 104 protocol, slave station
3. Signal generating device
Voltage level: 10kV and below
Zero sequence voltage starting value: adjustable from 20V to 100V
Protection level: IP65
Insulation level: One terminal withstand voltage to the shell
42kV/1min
75kV lightning wave impulse withstand voltage: 15 times positive and 15 times negative
Secondary terminal to shell
2kV/1min
Equipment lifespan: 10 years

6、 Order
The company needs to assist users in determining the installation location and total number of information collection and transmission devices. Both parties will negotiate on installation quantity, system price, installation cost, mobile card procurement, training expenses, etc.

7、 System maintenance
Generally, no user maintenance is required. If there is a device malfunction, the GZTC system will report it to the user.