HYXHX series 10kv Arc Suppression Cabinet
product description
In order to solve the long-term overvoltage problem of arc grounding, most of them used to install arc suppression coils at the neutral point to compensate the capacitive current to suppress the probability of arc occurrence at the fault point. Obviously, the purpose of this method is to eliminate the arc, but due to the many characteristics of the arc suppression coil itself, it is difficult to effectively compensate the capacitive current, especially the damage caused by the high frequency component to the power supply equipment cannot be overcome. On the basis of the arc suppression coil, our company has developed the YXHX intelligent arc suppression device.
working principle
●When the system is running normally, the microcomputer controller ZK of the device continuously detects the voltage signal provided by the voltage transformer PT.
●When the open triangle voltage U of the voltage transformer PT auxiliary secondary turns from low potential to high potential, it indicates that the system is faulty. At this time, the microcomputer controller ZK starts immediately, and at the same time according to the PT secondary output signals Ua, Ub, Uc Change to judge the fault type and phase difference:
A. If it is a single-phase PT disconnection fault, the microcomputer controller ZK will display the phase difference and disconnection signal of the disconnection fault, and output the passive switch contact signal at the same time
B. If it is a metal ground fault, the microcomputer controller ZK will display the phase difference and ground attribute signal of the ground fault, and at the same time output the passive switch contact signal. It can also send a closing action command to the vacuum contactor JZ in the cabinet according to the special requirements of the user. , can greatly reduce the contact voltage and step voltage, which is conducive to ensuring personal safety.
C. If it is an arc ground fault, the microcomputer controller ZK displays the ground fault phase difference and ground attribute signals, and at the same time sends a closing command to the vacuum contactor JZ of the fault phase to directly transform the arc ground into a metal ground, and the ground arc is due to two The arc voltage at the end is immediately reduced to zero, and the arc light is completely extinguished. If the power grid mainly consists of overhead lines, the vacuum contactor JZ of the device will automatically open after 5 seconds. If it is a transient fault, the system will return to normal. If it is a permanent fault, it will operate again to permanently limit the overvoltage. Function and output passive switch contact signal
D. If the device is equipped with an automatic line selection function, when the secondary open triangle voltage U of the voltage transformer PT assists from low potential to high potential, the small current grounding line selection module immediately performs data on the zero-sequence current of each line If there is no single-phase ground fault, it will return to normal; if there is a metal ground fault, the fault line will be selected according to the amplitude of the zero-sequence current of the line. Data collection is carried out on the zero-sequence current of the line, and the faulty line is selected according to the principle that the mutation amount of the faulty line is the largest before and after the grounding arc is extinguished.
Additional features of the device
●This device can be equipped with automatic line selection function according to user requirements.
●The HYLX small current grounding line selection device developed by our company mainly selects the line according to the amplitude of the zero-sequence current of the line when the system is metal grounded, and selects the line mainly based on the sudden change of the zero-sequence current of the line before and after the device operates when the system is grounded by arc light. It overcomes the shortcomings of the conventional line selection device, such as slow line selection speed and low line selection accuracy when the arc is grounded.
●This device can be equipped with the function of eliminating (removing) resonance (vibration) according to user requirements
●This device can be equipped with the special anti-saturation voltage transformer developed by our company and the primary current-limiting resonance eliminator, which fundamentally destroys the condition of ferromagnetic resonance and avoids “burning PT” and In case of “explosion PT insurance” accident; it can also be equipped with a microcomputer resonance elimination device to eliminate ferromagnetic resonance according to user requirements.
product model
scope of application
●This device is suitable for 3~35kV medium voltage power system;
The device is suitable for power systems where the neutral point is not grounded, the neutral point is grounded through the arc suppression coil, or the neutral point is grounded through high resistance;
●This device is suitable for power grids dominated by cable lines, mixed power grids of cables and overhead lines, and power grids dominated by overhead lines.
Technical Parameters
Features
When the device is working normally, it has the function of putting the dead body into the cabinet; at the same time, it has the function of system disconnection alarm and blocking; the system metal ground fault alarm, the function of transferring the system ground fault point; the function of eliminating arc light grounding and system resonance; low voltage and overvoltage alarm function ; and the function of recording information such as fault alarm elimination time, fault nature, fault phase difference, system voltage, opening three-free voltage, and ground capacitance current, which is convenient for fault handling and analysis.
●When a single-phase ground fault occurs in the system, the device can directly ground the faulty phase through a special phase-splitting vacuum contactor in about 30mS. If the arc is grounded, the arc will be extinguished immediately, and the arc ground overvoltage will stabilize the online voltage level, which can effectively avoid The phase-to-phase short circuit caused by single-phase grounding and the arrester explosion accident caused by arc grounding overvoltage; if it is metal grounding, it can greatly reduce the contact voltage and step voltage, which is conducive to ensuring personal safety (metal grounding can be set according to user requirements) action); if it is used in a power grid dominated by overhead lines, the vacuum contactor will automatically open after the device operates for 5 seconds. If it is a transient fault, the system will return to normal. Limit the effect of overvoltage.
●When a system disconnection fault occurs, the device will display the disconnection fault phase and output contact signals at the same time, so that the user can reliably lock the protection device that may cause malfunction due to disconnection.
●The device’s unique “intelligent switch (PTK)” technology can fundamentally suppress the occurrence of ferromagnetic resonance, and effectively protect against accidents such as burns and explosions caused by system resonance.
●The device is equipped with RS485 interface and adopts standard MODBUS communication protocol to ensure that the device is compatible with the entire monitoring system and realize data transmission and remote operation functions.
Other parameters
main feature
1. The device operates at a fast speed, and can act quickly within 30}40ms, which greatly shortens the duration of the single-phase grounding arc;
2. The arc can be extinguished immediately after the device operates, and the arc grounding overvoltage can be effectively limited within the line voltage range;
3. After the device operates, the system capacitive current is allowed to pass continuously for at least 2}1 hours, and the user can deal with the faulty line after completing the switching operation of transferring the load;
4. The protection function of the device is not affected by the scale and operation mode of the power grid;
5. The device has high functional cost performance, and the voltage transformer in it can provide voltage signals for metering and protection, replacing conventional transformers;
6. The device is equipped with a small current grounding line selection device, which can greatly improve the accuracy of line selection by using the characteristic of the largest zero-sequence current mutation of the fault line before and after the arc is extinguished.
7. The device adopts the combination of anti-saturation voltage transformer and special primary current limiting resonance eliminator, which can fundamentally suppress ferromagnetic resonance and effectively protect PT;
8. The device has the arc light grounding fault wave recording function, which provides data for users to analyze accidents.
