Product use

The device is suitable for underground coal mine with explosive dangerous gas and coal dust, and is suitable for 1140V, 660V, 127V low voltage neutral point ungrounded system power supply.

The device adopts the centralized idea of decentralized synchronous collection of leakage information, centralized judgment and decentralized control, and adopts the principle of multi-data fusion, the correct rate of line selection reaches 100%, and fully meets the safety technical requirements of 30mA.s in coal mine. It can not only protect personal safety, but also reduce the power failure model, and facilitate the search of fault lines, is an advanced and reliable selective leakage protection device. With optical fiber communication interface, it can access the power monitoring system through optical fiber to realize synchronous real-time remote monitoring.

Product overview

At present, the low voltage leakage protection in coal mine is realized by the leakage protection function in the feed switch, and its line selection principle is realized by the zero sequence current magnitude principle.

Because the transformer is neutral point ungrounded mode, each feed switch only depends on the fault of the branch to determine whether leakage occurs. However, the occurrence of low-voltage leakage faults requires the judgment of the entire power grid to accurately determine the fault line, so only relying on the collection of information of a single branch can not accurately determine the low-voltage leakage fault line, which is prone to misjudgment, rejection, and even cause leakage level tripping, resulting in greater power supply accidents.

Because the neutral point of coal transformer is not grounded, the selective leakage of low voltage feeder switch is poor at present. The device adopts zero sequence fundamental wave time sequence identification and uses CPLD, EDA, ASIC and other principles to fuse with each other, and adopts zero sequence current magnitude direction principle, zero sequence power direction principle and group ratio amplitude and phase method to synthetically judge whether leakage fault occurs. To achieve centralized selective leakage protection and avoid the limitation of a single principle, it is a centralized selective protection device for a variety of different modes of leakage faults.

Main feature

The shell adopts quick-opening, double-cavity structure design, modular installation, easy connection maintenance;

The control unit adopts FPGA+ dual-ARM embedded structural core processing technology, which has the characteristics of powerful function, fast processing speed and strong anti-interference ability.

Intelligent man-machine interface and fault information database query;

Strong intelligence, intelligent selection and conversion of a variety of principles, dynamic correction of system capacitance and system grid voltage on the impact of leakage resistance measurement accuracy;

At the same time, centralized monitoring of 1 main switch and 16 separate switches;

The correct rate of line selection is 100% by using multiple line selection comprehensive judgment.

No need to modify the existing low-voltage feed switch;

The state of incoming and outgoing lines can be set to achieve upper and lower control, and the leakage anti-tripping network can be formed.

Main technical parameters

Product application topology