CN203135432U - Arc-resonance extinction route-selecting over-voltage protection device - Google Patents

Abstract

The utility model provides an arc-resonance extinction route-selecting over-voltage protection device, which comprises an over-voltage integration protector, an isolation switch, a voltage transformer, a vacuum contactor, a high voltage fusing resistor and a ZRX controller, the lower end of the over-voltage integration protector enables ground connection, and a high voltage fuse is connected between the voltage transformer and the isolation switch in series. When the over-voltage protection device is accessed to a non-direct grounding system, the voltage transformer detects voltage of the non-direct grounding system, and voltage data is input to the ZRX controller, closing of a vacuum contactor is controlled through the ZRX controller, the arc extinguishing can be realized by closing of the vacuum contactor, large power which enables parallel connection at a voltage transformer secondary side opening triangle loop is used for destroying resonance parameter, consuming resonance energy and eliminating resonance fault, and over-voltage restriction protection during a breaking or closing process of the vacuum contactor can be realized through the over-voltage integration protector.

Description

Arc Suppression Harmonic Elimination Line Selection Overvoltage Protection Device

technical field

The utility model relates to the technical field of power distribution system safety maintenance, in particular to an overvoltage protection device for arc suppression, harmonic elimination, and line selection.           

Background technique

With the rapid development of the power system, the safe operation of the system and the reliability of power supply are critical issues. Due to the continuous increase of large-scale industrial and mining enterprises and residential electrical equipment. The distribution network in most areas of our country adopts the operation mode that the neutral point is not grounded, which causes the capacitive current of the grid to the ground to be much larger than before. After the single-phase grounding, the arc is not easy to extinguish, and the longer the arc exists, the gap generated The higher the arc ground overvoltage, the higher the accident rate will be.

Therefore, those skilled in the art urgently need to solve the problem of how to better eliminate arc hazards, while limiting arc overvoltage, resonant overvoltage and other types of overvoltage to a relatively low level.

Utility model content

In view of the above shortcomings, the purpose of this utility model is to provide an overvoltage protection device for arc suppression and harmonic elimination line selection.

The technical scheme that the utility model solves its technical problem adopts is:

An arc suppression and harmonic elimination line selection overvoltage protection device, which has an overvoltage comprehensive protector, an isolation switch, a voltage transformer, a vacuum contactor, a high-voltage fuse resistor, and a ZRX controller, wherein the upper end of the isolation switch is connected to the bus bar, and the lower end is respectively Connect the overvoltage comprehensive protector, high voltage fuse resistor and voltage transformer, the lower end of the voltage transformer is grounded, the lower end of the high voltage fuse resistor is connected to the upper end of the vacuum contactor, the ZRX controller is connected with the voltage transformer and the vacuum contactor respectively. The contactor is connected, the lower end of the overvoltage comprehensive protector is grounded, and a high voltage fuse is connected in series between the voltage transformer and the isolating switch.

The ZRX controller is provided with an RS485 communication interface.

The interface of the ZRX controller adopts optical/electrical isolation.

The overvoltage protection device for arc suppression, harmonic elimination and line selection is provided with a charged indicator, the upper end of the charged indicator is connected to the lower end of the isolating switch, and the lower end is grounded.

A capacitor is connected in series between the charged display and the isolating switch.

The vacuum contactor is a three-phase split high-voltage permanent magnet vacuum contactor.

The lower end of the vacuum contactor is grounded with a current transformer connected in series.

The beneficial effect of the utility model is that when the utility model is connected to the indirect grounding system, the voltage transformer detects the voltage of the system, and the voltage data is input to the ZRX controller, and the vacuum contactor is controlled by the ZRX controller to close, and the vacuum contactor The closure of the transformer realizes arc suppression. At the same time, through the high-power resonance elimination resistor connected in parallel to the open triangle circuit on the secondary side of the voltage transformer, the resonance parameter is destroyed, the resonance energy is consumed, and the resonance fault is eliminated. At the same time, the vacuum contact is realized through the overvoltage comprehensive protector. Overvoltage limit protection during the opening or closing process of the device.

Description of drawings

Fig. 1 is the electrical schematic diagram of the utility model.

In the figure, 1. Overvoltage comprehensive protector, 2. Current transformer, 3. Vacuum contactor, 4. High voltage fuse resistor, 5. Voltage transformer, 6. Live display, 7. Capacitor, 8. High voltage fuse, 9. Isolation switch, 10. ZRX controller.

Detailed ways

Embodiments of the utility model are further described below in conjunction with the accompanying drawings:

Referring to Fig. 1, the utility model has an overvoltage comprehensive protector 1, an isolating switch 9, a voltage transformer 5, a vacuum contactor 3, a high-voltage fuse resistor 4 and a ZRX controller 10, wherein the upper end of the isolating switch 9 is connected to the bus bar, and the lower end The integrated voltage protector 1, the high-voltage fuse resistor 4 and the voltage transformer 5 are respectively connected, the lower end of the voltage transformer 5 is grounded, the lower end of the high-voltage fuse resistor 4 is connected to the upper end of the vacuum contactor 3, and the ZRX controller 10 are respectively connected with the voltage transformer 5 and the vacuum contactor 3, the lower end of the integrated overvoltage protector 1 is grounded, and the high voltage fuse 8 is connected in series between the voltage transformer 5 and the isolating switch 9.

Overvoltage comprehensive protector 1 is the first device for limiting various overvoltages in the utility model, mainly used to limit atmospheric overvoltage and operating overvoltage, and it is composed of large-capacity ZnO nonlinear elements. The overvoltage comprehensive protector 1 is a special high-capacity zinc oxide overvoltage protector, which uses a large-capacity ZnO non-linear resistor and a discharge gap combined structure. Due to the cooperation of the gap element and the ZnO valve plate, the protector solves the problem of The charging rate and power frequency aging problem; the impact coefficient is 1, the discharge voltage value under various voltage waveforms is equal, not affected by the voltage waveform, the overvoltage protection value is accurate, and the protection performance is excellent; at the same time, it adopts four-star connection method , can greatly reduce the phase-to-phase overvoltage, compared with conventional surge arresters, the phase-to-phase overvoltage is reduced by 60-70%, and the protection reliability is greatly improved.

The vacuum contactor 3 is a three-phase split high-voltage permanent magnet vacuum contactor. The vacuum contactor 3 adopts a high-voltage permanent magnet vacuum contactor that can be controlled by phase separation. Its three-phase split body is connected to the busbar at one end of each phase. The other end is grounded. During normal operation, the vacuum contactor 3 is in the disconnected state. It is controlled by the ZRX controller 10 to act, and the phases are locked. When any phase is closed to ground the bus bar of this phase, any of the other two phases One phase will never act closed. When arcing grounding occurs in the system, it changes from an unstable arcing grounding fault to a stable metallic grounding, thereby protecting the equipment in the system.

The voltage transformer 5 can transform the high-voltage three-phase signal of the system into a three-phase voltage signal (Ua, Ub, Uc) and a neutral point signal (Uo) that can be processed by the ZRX controller.

The high-voltage fuse resistor 4 adopts a high-voltage current-limiting fuse resistor. As a backup protection device for the entire device, it has special functions such as large breaking capacity, rapid breaking, good current limiting effect, and low breaking arc voltage, ensuring compliance with the utility model. backup protection reliability.

The ZRX controller 10 is provided with an RS485 communication interface, which can report the real-time fault information of the system and the working conditions of the device to the control center.

The interface of the ZRX controller 10 adopts optical/electrical isolation, and adopts optical/electrical isolation as a method for the interface to resist electromagnetic interference, which can eliminate the interference of the power supply and the primary system to the controller, so that the ZRX controller 10 of the present utility model is resistant to electromagnetic interference. Good interference performance and high reliability.

The arc-extinguishing and harmonic-elimination line selection overvoltage protection device is provided with a charged display, the upper end of the charged display 6 is connected to the lower end of the isolating switch 9, and its lower end is grounded, and the ZRX controller can display the voltage data of the system in digital form, Data display is performed directly on the electrified display, which is convenient for observation.

A capacitor 7 is connected in series between the charged display 6 and the isolating switch 9, and the capacitor is charged and discharged to ensure the voltage stability of the charged display.

The lower end of the vacuum contactor 3 is grounded in series with the current transformer 2, which is used to detect the current value of the utility model, and is displayed by a charged display.

Arc suppression: When arc grounding occurs in the system, the ZRX controller 10 judges the grounding phase and the type of arc grounding, and at the same time issues an instruction to close the vacuum contactor 3 of the faulty phase, turning the unstable arc grounding fault of the system into a stable one. Metallic ground fault, the ground voltage of the fault phase drops to 0, the arc at the original ground fault point disappears, and the ground voltage of the other two phases rises to the line voltage.

After the vacuum contactor 3 is closed for a few seconds (according to the different grounding properties, the action time is different), the ZRX controller 10 will disconnect the vacuum contactor 3 of the faulty phase. If there is no arc ground fault phenomenon after the vacuum contactor 3 is disconnected, it means This ground fault is temporary, and the system returns to normal operation; if the arc light ground fault occurs again after the vacuum contactor 3 is disconnected, the vacuum contactor 3 will be closed for the second time, and after a few seconds, it will be disconnected for the second time; After the second disconnection, if the arc ground fault still occurs, the ZRX controller 10 will determine that the fault is a permanent arc ground fault. At this time, an instruction is issued to make the vacuum contactor 3 of the faulty phase close for the third time, and the ZRX controller 10 will send The alarm signal informs the staff on duty of the occurrence of the fault. When the vacuum contactor 3 is closed or disconnected, the transient overvoltage that occurs is limited and protected by the overvoltage comprehensive protector 1 .

Harmonic Elimination: This utility model adopts the secondary harmonic elimination technology of the microcomputer. When the system resonates, the ZRX controller 10 instantly connects a high-power harmonic elimination resistor to the open triangle winding of the voltage transformer 5, and uses the harmonic elimination resistor to destroy The resonance parameter of the system consumes resonance energy, thereby eliminating the resonance fault of the system. It has the characteristics of fast response time and high resonance elimination effect. The disadvantage that the harmonic elimination technology affects the voltage output of the voltage transformer 5 to protect the winding voltage.

The embodiment should not be regarded as limiting the utility model, but any improvement based on the spirit of the utility model should be within the protection scope of the utility model. the

Claims (7)

1. extinguishing arc resonance eliminating wire-selection overvoltage protection; it is characterized in that: have overvoltage comprehensive protection device (1); isolating switch (9); voltage transformer (5); vacuum contactor (3); high-voltage fuse resistance (4) and ZRX controller (10); wherein the upper end of isolating switch (9) is connected with bus; the lower end is taken over voltage comprehensive protection device (1) respectively; high-voltage fuse resistance (4) and voltage transformer (5); the lower end ground connection of described voltage transformer (5); the upper end of the following termination vacuum contactor (3) of described high-voltage fuse resistance (4); described ZRX controller (10) is connected with vacuum contactor (3) with voltage transformer (5) respectively; the high-tension fuse (8) of connecting between the lower end ground connection of described overvoltage comprehensive protection device (1), described voltage transformer (5) and isolating switch (9).

2. extinguishing arc resonance eliminating wire-selection overvoltage protection according to claim 1 is characterized in that, described ZRX controller (10) is provided with the RS485 communication interface.

3. extinguishing arc resonance eliminating wire-selection overvoltage protection according to claim 1 is characterized in that, the interface of described ZRX controller (10) adopts light/electricity to isolate.

4. extinguishing arc resonance eliminating wire-selection overvoltage protection according to claim 1; it is characterized in that; described extinguishing arc resonance eliminating wire-selection overvoltage protection is provided with electrification display, and described electrification display (6) upper end is connected its lower end ground connection with the lower end of isolating switch (9).

5. extinguishing arc resonance eliminating wire-selection overvoltage protection according to claim 4 is characterized in that, series capacitance (7) between described electrification display (6) and the isolating switch (9).

6. extinguishing arc resonance eliminating wire-selection overvoltage protection according to claim 1 is characterized in that, described vacuum contactor (3) is the high voltage permanent vacuum contactor of three-phase split.

7. according to claim 1 or 6 described extinguishing arc harmonic elimination overvoltage protections, it is characterized in that lower end series current instrument transformer (2) ground connection of described vacuum contactor (3).

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