Parallel resistance line selection equipment

Product Introduction:

The selection of fault line for neutral grounding through arc suppression coil has become a difficult problem that has plagued power supply system for a long time. Domestic and foreign research institutions and manufacturers have carried out a lot of research on this and introduced various fault line selection devices for small current grounding system based on different line selection principles. The operation results show that: The existing small current grounding line selection devices have different degrees of shortcomings, which affect the accuracy of the device line selection.

The basic principle of resistance line selection in parallel is to increase the active power component of zero sequence current in a short time through the back control of the parallel resistance, so that the zero sequence current on the fault line and the non-fault line have obvious feature difference, and then through a unique calculation method, accurately identify the fault line to achieve the purpose of line selection. It is proved by theory and practice that this method has high line selection accuracy and can suppress the neutral voltage, so it does not need to accurately judge the polarity of zero-sequence CT.

Use environment:

Installation location: indoor/outdoor

Temperature range: -5℃ ~ +45 ℃; Maximum change rate: 20℃/h.

Humidity: Relative humidity: 5% ~ 95%; Maximum absolute humidity: 28g/m3.

Atmospheric pressure: 86kPa ~ 108kPa.

Power requirements:

a) The AC power supply voltage is single-phase 220V, or three-phase 380V, and the allowable voltage deviation is -20% ~ + 15%;

b) AC power supply frequency 50Hz, allowable deviation + 5%;

c) AC power supply voltage waveform is sine wave, harmonic content is less than 5%;

d) The DC power supply voltage is 110V or 220V, and the allowable voltage deviation is -20% ~ + 15%;

e) The ripple coefficient of DC supply voltage is less than 5%.

Power loss: <100W

Frequency: 50Hz

Note: The above main technical indicators are for ordinary products, if you have other special requirements, please contact us first.

Product characteristics

The advantages of neutral resonance grounding and resistance grounding are synthesized by parallel connection of arc suppression coil. It not only maintains the advantages of accurate line selection for resistance grounding, but also reduces the residual current at the ground point, limits the arc grounding overvoltage, and ensures that the 10kV system runs for more than 2 hours with fault after single-phase grounding.

The line selection for non-metallic single-phase grounding fault is more accurate than other manufacturers.

It is not necessary to accurately judge the polarity of zero-sequence CT, and the line whose polarity is difficult to judge can also be correctly selected

All Chinese interface, operation and maintenance is simple and convenient: the microcomputer regulator is equipped with a large-screen LCD Chinese display screen, all menus are displayed in Chinese characters, the interface is clear, friendly, easy to view, easy to operate personnel maintenance and operation.

High reliability, strong anti-interference: the microcomputer regulator adopts secondary power technology, which can resist devastating electromagnetic interference, and the first and second systems all adopt optical/electrical isolation, which can eliminate the interference of the primary system to the line selection device. A dual Watchdog self-reset circuit is designed to realize the automatic recovery of the system.

Perfect telecontrol function: The system is designed with perfect telecontrol function, which can realize the connection with the traditional telecontrol device (RTU) and realize the remote monitoring of the system. The system also has two RS-232 and RS-485 serial interfaces, which can be used as a sub-station of the substation integrated automation system to connect to the integrated automation system.

Automatic cutting fault line function: when a single-phase grounding fault occurs, the industrial control computer calculates and analyzes the zero sequence voltage and current parameters of the fault, determines the grounding line, and can also quickly cut the fault line when equipped with a relay output module.

Product use

Suitable for 6-66KV voltage level of small current grounding system distribution network, in the power system substation and power plant has been widely used, in the mining, petrochemical and other enterprise power supply system is more and more widely used, to improve the reliability of the system power supply and safe operation has obvious effect.

Product parameter

Voltage level: 6kV, 10kV, 20kV, 35kV, 66kV

Communication interface: RS-232/RS-422/RS-485, Ethernet

Communication protocol: Built-in CDT, ISA, MODBUS and other protocols, IEC61850

Number of routes: 1 to 48 routes are optional

Fault wave recording: 500 fault waveforms can be recorded

Grounding information: can record 500 fault grounding information

Number of selected lines: 2 bus lines