CN212275853U

CN212275853U - Portable differential circuit calibrator

Info

Publication number: CN212275853U
Application number: CN201922440401.XU
Authority: CN
Inventors: 饶竹源; 魏波; 李娴; 陈楠; 金刚刚
Original assignee: Third Engineering Co Ltd of China Railway Construction Electrification Bureau Group Co Ltd
Current assignee: Third Engineering Co Ltd of China Railway Construction Electrification Bureau Group Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2021-01-01
Anticipated expiration: 2029-12-30

Abstract

The utility model provides a portable differential circuit check gauge, the differential circuit has two connecting terminal that are used for connecting current transformer, the check gauge includes central processing module, central processing module electric connection has constant current source module, man-machine interface module, signal acquisition module and power supply mechanism, wherein the constant current source module through two output terminal with connecting terminal is connected to constant current source module and power supply mechanism electric connection, man-machine interface module electric connection have man-machine interaction mechanism, the signal acquisition module include with output terminal electric connection's current signal collector and with constant current source module electric connection's temperature signal collector. The invention provides a portable differential circuit calibrator which has higher calibration result accuracy and calibration process efficiency.

Description

Portable differential circuit calibrator

Technical Field

The utility model relates to a current differential protection technical field, specific portable differential circuit check gauge that says so.

Background

The current differential protection is one of relay protection, and a current vector difference between both ends of an input CT (current transformer) starts an operation element when a set operation value is reached. Devices (which may be electrical devices such as lines, generators, motors, transformers, etc.) having a protection range between the two ends of the input CT generally serve as primary protection.

In a newly-built power supply system, because the current differential protection relates to the problem that a differential algorithm is matched with the polarities of a plurality of current mutual secondary coils, in a handover test, a great deal of time and energy are consumed for the traditional mode to check the differential protection system, and in addition, due to the fact that an observation method is mostly adopted to combine the principle to infer the correctness of the polarity of a differential loop, certain risks exist. Therefore, a test instrument which is convenient to carry, reliable in precision and capable of testing the differential protection circuit in an integrated manner is urgently needed on site.

SUMMERY OF THE UTILITY MODEL

In order to solve the deficiency among the prior art, the utility model provides a portable differential circuit check gauge, the efficiency of check-up result accuracy and check-up process is all higher.

In order to achieve the above object, the utility model discloses a concrete scheme does: the utility model provides a portable differential circuit check gauge, the differential circuit has two connecting terminal that are used for connecting current transformer, the check gauge includes central processing module, central processing module electric connection has constant current source module, man-machine interface module, signal acquisition module and power supply mechanism, wherein the constant current source module through two output terminal with connecting terminal is connected to constant current source module and power supply mechanism electric connection, man-machine interface module electric connection have man-machine interaction mechanism, the signal acquisition module include with output terminal electric connection's current signal collector and with constant current source module electric connection's temperature signal collector.

As a preferred scheme, the human-computer interaction mechanism comprises a liquid crystal display screen and a functional key which are electrically connected with the human-computer interface module.

As a preferred scheme, the power supply mechanism comprises an external AC power supply and an inverter power supply module which are electrically connected, wherein the inverter power supply module is electrically connected with both the central processing module and the constant current source module, and the external AC power supply is electrically connected with the constant current source module.

As a preferred scheme, the inverter power module comprises an IGBT and a phase shift controller, which are electrically connected, wherein the IGBT is electrically connected with both the central processing module and the inverter power module, and the phase shift controller is electrically connected with the output terminal.

As a preferable scheme, the central processing module includes a processor with a model of ATMEGA328p, and the temperature signal collector includes a temperature and humidity sensor with a model of DHT 22.

As a preferred scheme, the current signal collector comprises a straight-through current transformer, an AD converter and an operational amplifier which are electrically connected in sequence, wherein the straight-through current transformer is arranged on the side of the constant current source module, and the operational amplifier is electrically connected with the central processing module.

Has the advantages that: the utility model discloses utilize central processing module as core control ware, central processing module acquires the parameter of setting for through man-machine interface module and human-machine interaction mechanism, then control constant current source module to output stabilization current to output terminal, utilize stabilization current to carry out the check-up to differential circuit to control through signal acquisition module in the check-up process, with the steady operation of guaranteeing check gauge and differential circuit and acquire the accurate operational parameter of differential circuit. Adopt the utility model discloses, can utilize stabilization current to check up differential circuit in the certain limit, can avoid the unsafe problem of result that artifical dynamic verification probably produced to easy operation, convenient to use has improved verification efficiency by a wide margin.

Drawings

FIG. 1 is a block diagram of the structure of the calibration instrument of the present invention;

fig. 2 is a flow chart of a method of use of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1 and 2, a portable differential circuit calibrator, wherein a differential circuit has two connection terminals for connecting a current transformer, the calibrator includes a central processing module electrically connected to a constant current source module, a human-machine interface module, a signal acquisition module and a power supply mechanism, wherein the constant current source module is connected to the connection terminals through two output terminals, the constant current source module is electrically connected to the power supply mechanism, the human-machine interface module is electrically connected to a human-machine interaction mechanism, and the signal acquisition module includes a current signal collector electrically connected to the output terminals and a temperature signal collector electrically connected to the constant current source module.

The utility model discloses utilize central processing module as core control ware, central processing module acquires the parameter of setting for through man-machine interface module and human-machine interaction mechanism, then control constant current source module to output stabilization current to output terminal, utilize stabilization current to carry out the check-up to differential circuit to control through signal acquisition module in the check-up process, with the steady operation of guaranteeing check gauge and differential circuit and acquire the accurate operational parameter of differential circuit. Adopt the utility model discloses, can utilize stabilization current to check up differential circuit in the certain limit, can avoid the unsafe problem of result that artifical dynamic verification probably produced to easy operation, convenient to use has improved verification efficiency by a wide margin.

Furthermore, the man-machine interaction mechanism comprises a liquid crystal display screen and a function key which are electrically connected with the man-machine interface module. The LCD screen adopts an LCD 1602 LCD screen, and the function keys can adopt a matrix keyboard.

Furthermore, the power supply mechanism comprises an external AC power supply and an inverter power supply module which are electrically connected, wherein the inverter power supply module is electrically connected with the central processing module and the constant current source module, and the external AC power supply is electrically connected with the constant current source module. The external AC power supply selects a conventional 220V power supply, and the inverter power supply module is used for outputting low voltage to supply power to the control part of the central processing and constant current source module.

Furthermore, the inverter power supply module comprises an IGBT and a phase-shifting controller which are electrically connected, wherein the IGBT is electrically connected with the central processing module and the inverter power supply module, and the phase-shifting controller is electrically connected with the output terminal. The IGBT is used for receiving a signal from the central processing module and then controlling the phase shifting controller to operate, the IGBT is used as a control part of the constant current source module and also used for receiving low-voltage power supply from the inverter power supply module, and the phase shifting controller converts current from an external AC power supply into set current according to the control of the IGBT and outputs the set current from the output terminal.

Further, the central processing module comprises a processor with the model number of ATMEGA328p, and the temperature signal collector comprises a temperature and humidity sensor with the model number of DHT 22. In other embodiments of the present invention, other types of devices having the same function can be selected according to actual conditions.

Furthermore, the current signal collector comprises a straight-through current transformer, an AD converter and an operational amplifier which are electrically connected in sequence, wherein the straight-through current transformer is arranged on the side of the constant current source module, and the operational amplifier is electrically connected with the central processing module. In particular, a feedthrough current transformer is used to sense the current at a connection terminal.

The use method of the portable differential circuit calibrator comprises the steps S1 to S4.

And S1, initializing the check meter, and connecting the connecting terminal with the output terminal. Specific methods of S1 are S1.1 to S1.2.

S1.1, deploying a check meter and protecting and grounding the check meter.

And S1.2, correspondingly connecting the connecting terminal and the output terminal of the differential circuit.

And S2, sending a verification parameter to the central processing module through the human-computer interaction mechanism, wherein the verification parameter is a target current value.

And S3, the central processing module controls the constant current source module to output current to the differential circuit through the output terminal.

And S4, reading the differential current of the differential circuit when the current reaches the verification parameter, and if the differential current is 0, the differential circuit is normal.

And S5, acquiring the temperature value of the constant current source module through the temperature sensor, judging whether the temperature value exceeds a set temperature threshold value, if not, executing S6, otherwise, ending the verification.

And S6, judging whether the running time exceeds a set time threshold, continuing to check if the running time does not exceed the time threshold, and ending the check if the running time exceeds the time threshold.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A portable differential circuit verifier, said differential circuit having two connection terminals for connecting a current transformer, characterized in that: the calibration instrument comprises a central processing module, the central processing module is electrically connected with a constant current source module, a human-computer interface module, a signal acquisition module and a power supply mechanism, the constant current source module is connected with the connecting terminals through two output terminals, the constant current source module is electrically connected with the power supply mechanism, the human-computer interface module is electrically connected with a human-computer interaction mechanism, and the signal acquisition module comprises a current signal collector and a temperature signal collector, wherein the current signal collector is electrically connected with the output terminals, and the temperature signal collector is electrically connected with the constant current source module.

2. A portable differential circuit verifier as recited in claim 1, wherein: the man-machine interaction mechanism comprises a liquid crystal display screen and a functional key, wherein the liquid crystal display screen and the functional key are electrically connected with the man-machine interface module.

3. A portable differential circuit verifier as recited in claim 1, wherein: the power supply mechanism comprises an external AC power supply and an inverter power supply module which are electrically connected, wherein the inverter power supply module is electrically connected with the central processing module and the constant current source module, and the external AC power supply is electrically connected with the constant current source module.

4. A portable differential circuit verifier as recited in claim 3, wherein: the inverter power supply module comprises an IGBT and a phase-shifting controller which are electrically connected, wherein the IGBT is electrically connected with the central processing module and the inverter power supply module, and the phase-shifting controller is electrically connected with the output terminal.

5. A portable differential circuit verifier as recited in claim 1, wherein: the central processing module comprises a processor with the model of ATMEGA328p, and the temperature signal collector comprises a temperature and humidity sensor with the model of DHT 22.

6. A portable differential circuit verifier as recited in claim 1, wherein: the current signal collector comprises a straight-through current transformer, an AD converter and an operational amplifier which are electrically connected in sequence, wherein the straight-through current transformer is arranged on the side of the constant current source module, and the operational amplifier is electrically connected with the central processing module.