Suppression device for in-situ monitoring and arc absorption

Abstract

The utility model relates to the technical field of electric power protection, and discloses a suppression device for in-situ monitoring and arc absorption, which is characterized in that a first end of an isolation handcart is connected with a bus of a monitored power grid, a second end of the isolation handcart is connected with a first end of a high-voltage fuse, and a second end of the high-voltage fuse is connected with a first end of a voltage transformer; a neutral point outgoing line of the voltage transformer is connected with a first end of the primary resonance eliminator, a second end of the primary resonance eliminator is grounded, a neutral point outgoing line of the voltage transformer is connected with a first end of the instantaneous switch, and a second end of the instantaneous switch is grounded; the second end of the isolation handcart is also connected with the first end of the overvoltage protector, and the second end of the overvoltage protector is grounded; a secondary side opening triangle of the voltage transformer is connected to the intelligent microcomputer controller. When high-voltage fuse disconnection, overvoltage, low voltage, voltage loss, resonance, arc grounding and metal grounding occur in the system, the device can quickly and accurately judge the fault condition.

Description

TECHNICAL FIELD

[0001] The utility model relates to power protection technical field, concretely is a kind of suppression device of in-situ monitoring and absorbing electric arc. BACKGROUND

[0002] There are several overvoltages in 3-35 KV power supply system in China: operating overvoltage generated in the process of circuit breaker action, arc overvoltage generated in single-phase grounding and atmospheric overvoltage generated in lightning stroke, etc.At present, there is no complete protection scheme for these overvoltages, and power supply system still often has cable blasting, motor insulation breakdown, lightning arrester explosion and voltage transformer burning, etc.The reasons for such accidents are related to the performance of overvoltage protection products installed in the system, and the complexity of the system itself has an important influence on overvoltage.

[0003] For different systems, the type of power transmission line, the network structure of power transmission and distribution line, the nature of load and the grounding mode of system, etc.

[0004] For the current situation of overvoltage prevention and control difficulty in medium and low voltage system, the utility model provides a kind of suppression device of in-situ monitoring and absorbing electric arc. UTILITY MODEL CONTENTS

[0005] (I) technical problem solved

[0006] In view of the deficiencies of prior art, the utility model provides a kind of suppression device of in-situ monitoring and absorbing electric arc, makes up the deficiency of overvoltage protection element and device in system, monitors and effectively suppresses various overvoltages, and improves the overvoltage protection level of system.

[0007] (II) technical scheme

[0008] To achieve the above purpose, the utility model provides the following technical scheme:

[0009] A kind of suppression device of in-situ monitoring and absorbing electric arc, the device includes:

[0010] Isolation handcart, high-voltage fuse, voltage transformer, overvoltage protector, primary harmonic absorber, instantaneous switch, intelligent microcomputer controller;

[0011] The first end of the isolation handcart is connected with a bus of a monitored power grid, the second end of the isolation handcart is connected with a first end of a high-voltage fuse, a second end of the high-voltage fuse is connected with a first end of a voltage transformer, a neutral point lead of the voltage transformer is connected with a first end of a primary harmonic eliminator, a second end of the primary harmonic eliminator is grounded, the neutral point lead of the voltage transformer is connected with a first end of a transient switch, and a second end of the transient switch is grounded.

[0012] The second end of the isolation handcart is also connected with a first end of the overvoltage protector, and a second end of the overvoltage protector is grounded.

[0013] The secondary side open delta of the voltage transformer is connected to the intelligent microcomputer controller.

[0014] The intelligent microcomputer controller is used for controlling the primary harmonic eliminator, and the primary harmonic eliminator is used for eliminating primary side resonance of the system.

[0015] In a possible implementation, the device further comprises a live sensor and a live display, wherein the second end of the isolation handcart is connected with a first end of the live sensor, the second end of the live sensor is connected with a first end of the live display, and a second end of the live display is grounded.

[0016] (Three) beneficial effects

[0017] Compared with the prior art, the device provided by the utility model has the following beneficial effects:

[0018] The device is provided with a single-phase transient switch, which fundamentally solves the harm caused by the ferromagnetic resonance of the system. When the system has three-phase potential imbalance and gap arc grounding, the device can solve the problem that the current of the live sensor to the ground will pass through the PT and cause PT burning or the fusing of the fuse.

[0019] When the device is normally operated, the three-phase voltage, the PT open delta voltage and the zero sequence current of each feeding loop are monitored in real time. Once the system has high-voltage fuse wire breakage, overvoltage, low voltage, voltage loss, resonance, arc grounding or metal grounding, the device can quickly and accurately judge the fault condition, display the fault category, output the corresponding switch quantity contact signal, the related device acts and alarms. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A principle diagram of a device for monitoring and absorbing arc in situ is shown.

[0021] Reference signs:

[0022] Isolation handcart 1, high-voltage fuse 2, voltage transformer 3, overvoltage protector 4, primary harmonic eliminator 5, transient switch 6, intelligent microcomputer controller 7, live display 8 and live sensor 9. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be apparently and completely described in connection with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative labor belong to the scope of protection of the utility model.

[0024] Please refer to Figure 1 A kind of suppression device of arc monitoring and absorbing in situ, the device includes:

[0025] Isolation handcart, high voltage fuse, voltage transformer, overvoltage protector, primary harmonic absorber, instantaneous switch, intelligent microcomputer controller;

[0026] Among them, the first end of isolation handcart is connected to the bus of monitored power grid, the second end of isolation handcart is connected to the first end of high voltage fuse, the second end of high voltage fuse is connected to the first end of voltage transformer, the neutral point lead of voltage transformer is connected to the first end of primary harmonic absorber, the second end of primary harmonic absorber is grounded, the neutral point lead of voltage transformer is connected to the first end of instantaneous switch, the second end of instantaneous switch is grounded;

[0027] The second end of isolation handcart is also connected to the first end of the overvoltage protector, and the second end of the overvoltage protector is grounded.

[0028] The open delta connection of the secondary side of voltage transformer is connected to the intelligent microcomputer controller;

[0029] The intelligent microcomputer controller is used to control the primary harmonic absorber, and the primary harmonic absorber is used to eliminate the primary side resonance of system.

[0030] In a possible implementation, the device further includes a live line sensor and a live line display, wherein the second end of the isolation handcart is connected to the first end of the live line sensor, the second end of the live line sensor is connected to the first end of the live line display, and the second end of the live line display is grounded.

[0031] Working principle:

[0032] Operation monitoring function: the intelligent microcomputer controller calculates the A, B and C three-phase voltages collected by the voltage transformer, the open delta voltage and the current signal on the secondary side of the current transformer in real time. The effective values of the system operation phase voltage, line voltage and current are displayed on the display panel of the suppression device, replacing the conventional PT cabinet (voltage transformer cabinet) monitoring instrument.

[0033] Loss of voltage fault is that the voltage of ABC three-phase is less than 5V. Low voltage fault is that the voltage of ABC three-phase is less than 5V. Over voltage fault is that the voltage of ABC three-phase is greater than 80V.

[0034] Out of limit alarm function: when the line voltage of the system exceeds or is lower than the pre-set limit value (the default is more than 80V or less than 40V), the system can give an alarm in time, the panel displays the fault type and the voltage at the time of the fault, and outputs a pre-warning signal, so that the user can give an alarm or trip operation according to the pre-warning signal of the suppression device.

[0035] Wire break alarm function: when the open delta voltage exceeds the limit value (about 30V) and the voltage of the non-fault phase is normal, the system determines whether the high voltage fuse is broken according to whether the phase voltage is lower than the limit value (30V). Once the system has a wire break fault, the display panel of the suppression device displays the type of the wire break phase and the three-phase voltage.

[0036] Grounding alarm function: when the open delta voltage exceeds the limit value (about 45V) and the voltage of two phases is close to or exceeds the line voltage, the suppression device determines whether it is a single-phase arc grounding or a single-phase metal grounding fault according to the change of the fault phase voltage to ground.

[0037] For example, when the voltage of phase A is less than or equal to 6V and the voltage of phases B and C is greater than 85V, it is determined to be a metal grounding fault. When the voltage of phase A is between 6V and 53V and the voltage of phases B and C is greater than 85V, it is determined to be a single-phase arc grounding fault.

[0038] Resonance elimination function: when the open delta voltage exceeds the limit value, the device immediately performs open delta voltage amplitude operation and Fourier series analysis, and determines the type of ferromagnetic resonance according to the amplitude and frequency of the open delta voltage. If it is determined to be a ferromagnetic resonance fault, the system immediately starts the microcomputer resonance elimination function to disconnect the primary resonance eliminator and put in the corresponding damping resistance (in the intelligent microcomputer controller) or instantaneous switch, while recording the fault data at the time of the fault. The recorded fault data includes fault time, resonance type, open delta voltage and phase voltage. When the resonance fault disappears, the primary resonance eliminator is put in and the display screen returns to the normal voltage monitoring interface.

[0039] System harmonic monitoring function: based on the principle of fast Fourier transform, the operation result is fast and accurate. It can monitor and analyze the fundamental wave and 2-21th harmonic of the voltage of the bus and line in the power grid in real time, and give an alarm for harmonic out of limit.

[0040] Data remote transmission function: the suppression device is equipped with an RS485 communication interface, which can realize data remote transmission with the background monitoring system according to the given communication protocol (MODBUS communication protocol). The user can monitor the system operating voltage and current in real time, review the fault type, fault state and electrical parameters at the time of the fault in the monitoring center.

[0041] Event record and fault alarm function: no matter which level the display screen interface is, once a fault occurs, a fault interface is popped up immediately, the fault type, fault time, fault parameter and the like are displayed, meanwhile, the system automatically records 200 times of fault information and outputs an alarm contact.

[0042] Waveform viewing function: the real-time waveform is viewed for the secondary voltage.

[0043] Control primary harmonic eliminator (PTK) on-off function: after the system ferromagnetic resonance fault, the microcomputer controller harmonic elimination function is put into the damping resistor to realize the secondary harmonic elimination, meanwhile, the primary harmonic eliminator is controlled by the relay to be put into work, so that the effect of eliminating the ferromagnetic resonance is better, and after the resonance elimination, the primary harmonic eliminator is withdrawn, so that the neutral point of the secondary winding of the voltage transformer is directly grounded.

[0044] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. An arc monitoring and absorbing suppression device in-situ, characterized by, The device comprises: an isolation trolley, a high-voltage fuse, a voltage transformer, an overvoltage protector, a primary harmonic eliminator, a transient switch, and an intelligent microcomputer controller; wherein the first end of the isolation trolley is connected to a busbar of a monitored power grid, the second end of the isolation trolley is connected to the first end of the high-voltage fuse, the second end of the high-voltage fuse is connected to the first end of the voltage transformer, the neutral point lead of the voltage transformer is connected to the first end of the primary harmonic eliminator, the second end of the primary harmonic eliminator is grounded, the neutral point lead of the voltage transformer is connected to the first end of the transient switch, and the second end of the transient switch is grounded; the second end of the isolation trolley is also connected to the first end of the overvoltage protector, and the second end of the overvoltage protector is grounded; the open delta connection on the secondary side of the voltage transformer is connected to the intelligent microcomputer controller; the intelligent microcomputer controller is used to control the primary harmonic eliminator, and the primary harmonic eliminator is used to eliminate the primary side resonance of the system.

2. The arc monitoring and absorbing suppression device of claim 1, wherein, The device further comprises a live sensor and a live display; wherein the second end of the isolation trolley is connected to the first end of the live sensor, the second end of the live sensor is connected to the first end of the live display, and the second end of the live display is grounded.

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