CN215833539U

CN215833539U - Switch cabinet transient ground signal acquisition device

Info

Publication number: CN215833539U
Application number: CN202121624810.6U
Authority: CN
Inventors: 于文明; 马德平; 陈双强; 陈国斌; 李康; 刘明鑫; 马吉琛; 牧继清; 崔飞飞; 白巧真; 李俊岭; 吴万里; 陶志豪; 于高均
Original assignee: ZHENGZHOU JINGCHENG ELECTRIC POWER EQUIPMENT CO LTD
Current assignee: Zhengzhou Jingcheng Intelligent Technology Co ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2022-02-15
Anticipated expiration: 2031-07-16

Abstract

The utility model discloses a transient ground signal acquisition device of a switch cabinet, which aims to solve the problems of low sensitivity and weak anti-interference capability of the existing transient ground detection equipment. The device comprises a coupling module, a filtering module, an amplifying module and a frequency reducing module, wherein the coupling module is arranged on a shell of the switch cabinet, the coupling module is correspondingly connected with the input end of the filtering module, the output end of the filtering module is correspondingly connected with the input end of the amplifying module, the output end of the amplifying module is correspondingly connected with the input end of the frequency reducing module, and the output end of the frequency reducing module is used for outputting transient ground signals of the switch cabinet. The utility model has the beneficial effects that: high sensitivity, high anti-interference ability and high precision.

Description

Switch cabinet transient ground signal acquisition device

Technical Field

The utility model relates to the technical field of transient ground signal detection, in particular to a switch cabinet transient ground signal acquisition device.

Background

When a fault occurs in the power equipment, the electromagnetic wave excited by the partial discharge pulse can generate an instantaneous voltage to ground on the metal shell of the equipment, and the insulation state in the equipment can be judged by detecting the voltage.

The conventional detection methods mainly include a pulse current method, an ultrasonic method, a radio frequency method, an ultrahigh frequency method, and the like. However, the method is mostly used for testing the faults of the power cable, and for the switch cabinet equipment, the switch cabinet equipment is easily affected by background noise interference, and when partial discharge occurs, transient ground voltage signals generated are only a few millivolts to a few volts and are difficult to acquire.

Disclosure of Invention

The utility model provides a switch cabinet transient ground signal acquisition device, which aims to solve the problems of low sensitivity and weak anti-interference capability of the existing transient ground detection equipment.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the utility model provides a cubical switchboard transient state ground signal pickup assembly, includes coupling module, filtering module, amplification module, the module of falling frequency, coupling module sets up on the shell of cubical switchboard, coupling module with filtering module's input corresponds the connection, filtering module's output with amplification module's input corresponds the connection, amplification module's output with the input of the module of falling frequency corresponds the connection, the output of the module of falling frequency is used for exporting the transient state ground signal of cubical switchboard.

Preferably, the coupling module includes an insulating film and a metal electrode, the insulating film is disposed on the outer shell of the switch cabinet, and the metal electrode is disposed on the insulating film.

Preferably, the filtering module includes a diode D3, a first capacitor, and a first resistor, the diode D3 is correspondingly connected to the output end of the coupling module, the first capacitor is connected in series between the coupling module and the amplifying module, one end of the first resistor is connected to the first capacitor, and the other end of the first resistor is grounded.

Preferably, the amplifying circuit comprises a reference voltage source IC and an amplifier IC, an output terminal of the reference voltage source IC is connected with an input pin of the amplifier IC, the input pin of the amplifier IC is connected with an output terminal of the filtering module, and an output pin of the amplifier IC is connected with an input terminal of the frequency reducing circuit.

Preferably, the down-conversion circuit comprises an envelope detector for outputting a signal available for the ADC to collect.

Preferably, the envelope detector is integrated within a high bandwidth RMS power detector.

Compared with the prior art, the utility model has the main beneficial technical effects that:

1. the capacitive coupling module is used for receiving transient ground signals, clutter is filtered by the filtering module to obtain required signals, weak signals are amplified by the amplifying circuit, and required low-frequency signals are obtained by the frequency reduction module.

2. The utility model adopts a demodulation logarithmic operational amplifier with the bandwidth as high as 4GHz, and the back end outputs signals for ADC to collect through a high-bandwidth envelope detector, so that the data collection is accurate.

Drawings

Fig. 1 is a schematic structural diagram of a coupling module of the transient ground signal acquisition device of the switch cabinet of the utility model.

Fig. 2 is a circuit diagram of a filtering module of the transient ground signal acquisition device of the switch cabinet of the utility model.

Fig. 3 is a circuit diagram of an amplifying module of the transient signal acquisition device of the switch cabinet of the utility model.

Fig. 4 is a circuit diagram of a frequency reduction module of the transient ground signal acquisition device of the switch cabinet of the utility model.

Fig. 5 is a circuit diagram of a power supply module of the transient ground signal acquisition device of the switch cabinet of the utility model.

In the figure, 1 is a GIS housing, 2 is an insulating film, and 3 is a metal electrode.

Detailed Description

The following examples are intended to illustrate the present invention in detail and should not be construed as limiting the scope of the present invention in any way.

Example 1: the utility model provides a cubical switchboard transient state ground signal pickup assembly, refers to fig. 1 to 5, including coupling module, filtering module, amplification module, the module that reduces the frequency, receives transient state ground signal through capacitive coupling module, obtains required signal through filtering module filtering clutter, passes through amplifier circuit and amplifies weak signal, finally obtains required low frequency signal through the module that reduces the frequency. The low-frequency signal can be collected by the ADC, converted into a digital signal, then input into a single chip microcomputer controller, a display and other rear-end equipment to display the discharging condition of the switch cabinet, or can be connected with an alarm device and other warning devices.

The coupling module adopts an external composite electrode method, referring to fig. 1, an insulating film 2 and a metal electrode 3 are laid on a GIS shell 1, the metal electrode 3 and the insulating film 2 form a capacitor-like structure, and the metal electrode 3 can be coupled to a transient ground voltage. The voltage firstly enters a filter module, referring to fig. 2, P1 is an interface between a metal electrode 3 of a coupling module and a GIS housing 1, pin 1 is connected with the metal electrode 3, pin 2 and pin 3 are commonly grounded, a diode D3 is connected between pin 1 and

pins

2 and 3, meanwhile, the anode of a diode D3 is connected with a capacitor C119, a capacitor C82 and filter banks C83, LFCN-80 and C84 are connected in series behind the capacitor C119, a resistor R49 is connected between the capacitor C119 and the capacitor C82, a resistor R50 and an inductor L23 are connected between the capacitor C82 and the filter banks, resistors R46 and R51 connected in parallel are connected on the right side of the filter banks, resistors R47 and R48 are connected between the capacitor C81 are connected at the output end of R48, and an output end a of the capacitor C81 is connected with the input end of an amplifying module.

Referring to fig. 3, an a terminal is connected to an input terminal 2 pin of an amplifier IC, a transient ground signal obtained by a coupling module can reach GHz level, so a demodulation logarithmic operation amplifier with a bandwidth as high as 4GHz is adopted in the amplification module, a 9 pin of the amplifier is connected to a reference voltage source IC, a power supply terminal connected to the input terminal 3 pin and the 4 pin of the reference voltage source is connected to a dc power supply VCC _ TEV through an inductor L22,

pins

5 and 6 at an output terminal are connected to the 9 pin of the amplifier IC through an inductor L21 and a resistor R77, the amplifier provides a stable 20 dB gain, the gain does not change with frequency, temperature, power supply and devices, the stability is high, and a pin 12 VOUT at the output terminal is connected to an input terminal of a frequency reduction module through a capacitor C10.

Referring to fig. 4, the output terminal B of the amplifying module is connected to pin 3 INP of the down-converting IC through resistor R57, resistor R58, and capacitor C100, and pin 4 INN of the other input terminal is grounded after being absorbed by the resistor-capacitor. The frequency reduction IC adopts an RMS power detector integrated with a high-bandwidth envelope detector, the RMS output is RF real signal power represented by temperature compensation type, monotone and linear dB, the input detection range of 70 dB is adopted for measurement, the built-in envelope detector can provide accurate voltage output, and the voltage output is in linear proportion to the envelope amplitude of an RF input signal with the modulation bandwidth of up to 150 MHz. The high bandwidth envelope detection of the down-converting IC makes it suitable for detecting commonly used wideband and high crest factor RF signals, and in addition, the instantaneous envelope output can be used to implement an envelope tracking PA for fast RF over-power protection, PA linearization, and enhanced efficiency. The RMS detector integration bandwidth of the down-conversion IC can be digitally programmed with over 40 times the range of input pin SCI1-4, thus allowing the user to dynamically set the operating bandwidth and also support different types of modulation detection on the same platform.

The chips are driven by the power circuit shown in fig. 5, a grounded filter capacitor C8 and a grounded filter capacitor C9 are arranged on a 3.3V direct current power supply, a power supply end VCC _ TEV is obtained through a fuse F6 and supplies power to an operational amplifier IC and a reference power supply IC in the amplification module, and the VCC _ TEV obtains a power supply VDDA through 6 sets of filter capacitors C85-C90 and supplies power to the down-conversion IC.

While the utility model has been described in detail with reference to the drawings and examples, it will be understood by those skilled in the art that various changes in the specific parameters of the embodiments described above may be made or equivalents may be substituted for elements, structures and materials thereof without departing from the scope of the utility model, and therefore, all matters in the embodiments are to be understood as being modified within the scope of the utility model and not to be described in detail herein.

Claims

1. The utility model provides a cubical switchboard transient state ground signal pickup assembly which characterized in that: including coupling module, filtering module, amplification module, the module of falling frequency, coupling module sets up on the shell of cubical switchboard, coupling module with filtering module's input corresponds the connection, filtering module's output with amplification module's input corresponds the connection, amplification module's output with the input of the module of falling frequency corresponds the connection, the output of the module of falling frequency is used for exporting the transient state ground signal of cubical switchboard.

2. The switchgear cabinet transient signal acquisition device according to claim 1, wherein: the coupling module comprises an insulating film and a metal electrode, the insulating film is arranged on the shell of the switch cabinet, and the metal electrode is arranged on the insulating film.

3. The switchgear cabinet transient signal acquisition device according to claim 1, wherein: the filtering module comprises a diode D3, a first capacitor and a first resistor, the diode D3 is correspondingly connected with the output end of the coupling module, the first capacitor is connected in series between the coupling module and the amplifying module, one end of the first resistor is connected with the first capacitor, and the other end of the first resistor is grounded.

4. The switchgear cabinet transient signal acquisition device according to claim 1, wherein: the amplifying circuit comprises a reference voltage source IC and an amplifier IC, wherein the output end of the reference voltage source IC is connected with the input pin of the amplifier IC, the input pin of the amplifier IC is connected with the output end of the filtering module, and the output pin of the amplifier IC is connected with the input end of the frequency reduction circuit.

5. The switchgear cabinet transient signal acquisition device according to claim 1, wherein: the frequency reducing circuit comprises an envelope detector and is used for outputting signals which can be collected by the ADC.

6. The switch cabinet transient signal acquisition device of claim 5, wherein: the envelope detector is integrated within a high bandwidth RMS power detector.