Line protection measurement and control device is a power automation equipment that integrates protection, measurement, control, and communication. It is mainly installed in power facilities such as substations and distribution rooms, and is used for real-time monitoring, fault removal, and remote control of faults and operating status of transmission lines (such as overhead lines and cables). ​

Its core value lies in the ability to identify the fault type and issue a trip command within milliseconds when faults such as short circuit, overload, and grounding occur in the power line, cutting off the faulty line and avoiding the fault from expanding and affecting the entire power grid; At the same time, it can continuously collect operational data such as voltage, current, and power of the line, providing accurate equipment status information for the dispatch center and assisting operation and maintenance personnel in fault analysis and equipment management.

The application scenarios of line protection measurement and control devices are wide, from high-voltage transmission to low-voltage distribution network, almost all lines need to be configured. The following are three typical scenarios:

1. High voltage transmission lines (110kV and above)

In high-voltage transmission lines such as 220kV and 500kV, the device needs to have protection characteristics of "speed, selectivity, and sensitivity":

Adopting "longitudinal differential protection" as the main protection (accurately determining internal faults by comparing the currents at both ends of the line), with an action time of less than 0.05 seconds; ​

Equipped with "distance protection" as a backup protection, the action time can be adjusted according to the distance of the fault point to avoid indiscriminate disconnection of the line; ​

It is necessary to support the IEC 61850 protocol and connect to the integrated monitoring system of intelligent substations to achieve data sharing and collaborative control. ​

2. Medium voltage distribution network lines (10kV-35kV)

Medium voltage distribution network is the "bridge" connecting substations and users, with multiple branches and high probability of faults. The equipment needs to focus on "fault location and rapid recovery":

For single-phase grounding faults, configure the "small current grounding line selection function" to quickly locate the faulty line (avoiding the blindness of traditional "pulling and testing"); ​

Support "reclosing function": automatically reclose the circuit breaker after fault removal (if it is an instantaneous fault, power supply can be restored to reduce power outage time); ​

Connect to the distribution network automation system and upload data through GPRS/4G communication module to meet the monitoring needs of remote area lines. ​

3. Internal power lines of industrial enterprises (0.4kV-10kV)

Industrial enterprises (such as factories and parks) have large fluctuations in line load and multiple types of equipment, and their installations need to balance "protection and production continuity":

Configure "overload delay protection" (to avoid false tripping caused by short-term overload such as motor start-up); ​

Equipped with "energy metering function", providing data for internal energy consumption statistics and cost allocation of enterprises; ​

Support communication with PLC and DCS systems to achieve linkage control between production lines and power systems (such as automatic disconnection of non critical equipment in case of load overload).