CN216926923U

CN216926923U - Instrument capable of measuring direct resistance of opening and closing coil of circuit breaker with rectifier module

Info

Publication number: CN216926923U
Application number: CN202220324149.5U
Authority: CN
Inventors: 万阳; 陈腾渊; 王恒杰; 王连龙; 汪健; 陈浩; 黄冯; 汤玉龙; 詹琛; 王恒招; 贺云虎; 邹刚; 陆智勇; 王平; 朱兴刚; 江明
Original assignee: State Grid Anhui Electric Power Co ltd Lu'an Power Supply Co
Current assignee: State Grid Anhui Electric Power Co ltd Lu'an Power Supply Co
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2022-07-08
Anticipated expiration: 2032-02-17

Abstract

The utility model discloses an instrument capable of measuring direct resistance of a switching-on and switching-off coil of a circuit breaker with a rectification module, which comprises a shell, wherein the surface of the shell is provided with a plurality of keys and a liquid crystal display screen, a battery and a test circuit board are arranged in the shell, and the test circuit board comprises a power module, a constant current and signal conditioning module, a CPU and a sampling module, wherein the constant current and signal conditioning module is connected with the output end of the power module; the power supply module is powered by a battery, converts the voltage of the battery into +/-15V and +/-3.3V and respectively supplies power to the constant current and signal conditioning module, the CPU and the sampling module; the constant current and signal conditioning circuit is connected with the CPU and the sampling module and is used for providing various constant current and conditioning voltage signals; the CPU and the sampling module are used for controlling the detection of the external interface and the electric quantity of the battery. According to the utility model, the rectification module is not required to be dismounted and restored, and the measurement is directly carried out on the alternating current side of the rectification module, so that the test time is greatly reduced, and the controllability of the site safety is improved.

Description

Instrument capable of measuring direct resistance of opening and closing coil of circuit breaker with rectifier module

Technical Field

The utility model relates to the technical field of electric power detection, in particular to an instrument capable of measuring direct resistance of a switching-on and switching-off coil of a circuit breaker with a rectification module.

Background

The defects of the material quality and the manufacturing process of the opening and closing coil of the circuit breaker cause the problem that the resistance of the coil is unqualified occasionally, and hidden danger is brought to the normal action of the circuit breaker. The traditional multimeter measurement method is accurate in measurement when only coils are in a switching-on and switching-off control circuit, but rectification modules exist in partial switching-on and switching-off coil circuits used in actual transformer substation engineering, data cannot be measured by the multimeter at the moment, and great difficulty is brought to measurement work.

All there is the rectifier module before present most circuit breaker divide-shut brake coil, unable direct measurement, need demolish the rectifier module during actual measurement, the manpower that the operation needs like this, the material resources are more, work load is big, the efficiency ratio is lower, and need can just demolish and resume work to the staff that the inner structure of various circuit breakers is very familiar, the in-process can cause wiring mistake or contact failure grade hidden danger, the operation risk increases, consequently need urgently to provide one kind and can take the rectifier module to measure the instrument of circuit breaker divide-shut brake coil direct resistance to solve above-mentioned problem.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of providing an instrument capable of measuring the direct resistance of the opening and closing coil of the circuit breaker with a rectifier module, the rectifier module is not required to be dismounted and restored, the measurement is directly carried out on the alternating current side of the rectifier module, and the test time is greatly reduced.

In order to solve the technical problems, the utility model adopts a technical scheme that: the instrument comprises a shell, wherein the surface of the shell is provided with a plurality of keys and a liquid crystal display screen, a battery and a test circuit board are arranged in the shell, and the test circuit board comprises a power supply module, a constant current and signal conditioning module, a CPU and a sampling module, wherein the constant current and signal conditioning module is connected with the output end of the power supply module;

the power module is powered by a battery, converts the voltage of the battery into +/-15V and +/-3.3V and respectively supplies power for the constant current and signal conditioning module, the CPU and the sampling module, and comprises a switch J4, an isolation power chip J6, a 3.3V voltage conversion circuit and a 5V voltage conversion circuit;

the constant current and signal conditioning circuit is connected with the CPU and the sampling module, is used for providing various constant current and conditioning voltage signals, and comprises a constant current driving circuit, a current detection circuit and a voltage detection circuit which are all connected with the CPU;

the CPU and the sampling module are used for controlling the detection of the external interface and the battery power, and comprise a CPU, a reset circuit connected with the CPU, a battery power detection circuit, a liquid crystal interface J3 and a keyboard interface J2.

In a preferred embodiment of the present invention, the side of the housing is provided with a charging port, and the switch J4 is also provided on the side of the housing.

In a preferred embodiment of the present invention, the test circuit board further includes a key circuit and a liquid crystal display circuit, both of which are connected to the CPU, and the power module provides +5V voltage to the liquid crystal display circuit.

In a preferred embodiment of the present invention, the 3.3V voltage converting circuit includes a linear regulator chip U7, capacitors C8, C9, and polar capacitors C15 and C16, wherein the capacitor C8 is connected in parallel with the polar capacitor C15 and then connected to the port Vin of U7 and GND, and the capacitor C9 is connected in parallel with the polar capacitor C16 and then connected to the port Vout and GND of U7.

In a preferred embodiment of the present invention, the 5V voltage conversion circuit includes a buck chip U6, a capacitor C7, a capacitor C14, an electrolytic capacitor C13, a diode D1, and an inductor L1.

In a preferred embodiment of the present invention, the power module provides 12V voltage for the constant current driving circuit and ± 15V voltage for the voltage detection circuit.

In a preferred embodiment of the present invention, the constant current driving circuit includes a MAX333 chip U5, a linear constant current chip U1, a resistor R1, a capacitor C1, and resistors R6 to R9, and the MAX333 chip U5 and the resistors R1, R6 to R9 form a current step switching circuit for providing multiple constant currents.

In a preferred embodiment of the utility model, the voltage detection circuit comprises an AD620 high-precision instrument amplifier U4, and capacitors C4 and C6 for conditioning voltage signals.

In a preferred embodiment of the present invention, the battery power detection circuit includes resistors R10 and R11, one end of R10 and one end of R11 are connected in parallel and then connected to port P0.2 of the CPU, the other end of R10 is connected to the battery voltage, and the other end of R11 is grounded.

Further, the CPU employs a micro control chip C8051F 850.

The utility model has the beneficial effects that:

(1) according to the device, the rectification module is not required to be dismounted and restored, the measurement is directly carried out on the alternating current side of the rectification module, the test time is greatly reduced, the accident that equipment is damaged due to misoperation in the process of dismounting the circuit breaker is avoided to the greatest extent, and the controllability of field safety is improved;

(2) the measuring device has small volume and light weight, can complete the test without being particularly familiar with the internal structure of the circuit breaker, and has simple operation, thereby reducing the number of operators;

(3) the application of the device greatly improves the testing efficiency, shortens the power failure time, reduces the operation risk of a power grid, improves the power supply reliability of a transformer substation, standardizes the field operation behavior, realizes the direct resistance testing operation of the opening and closing coil, is simple and easy to operate, changes the jiong position which cannot be measured by a rectifier module of the traditional multimeter, simplifies the operation flow, shortens the power failure time and improves the power supply reliability.

Drawings

FIG. 1 is a structural diagram of an instrument for measuring direct resistance of a switching-on and switching-off coil of a circuit breaker, which can be provided with a rectification module, of the utility model;

FIG. 2 is a block diagram of the schematic structure of the test circuit board;

FIG. 3 is a specific structural block diagram of the apparatus for measuring direct resistance of the opening and closing coil of the circuit breaker with the rectifier module;

FIG. 4 is a circuit diagram of the power supply module;

FIG. 5 is a circuit diagram of the constant current and signal conditioning module;

fig. 6 is a circuit diagram of the CPU and the sampling module.

The parts in the drawings are numbered as follows: 1. casing, 2, button, 3, liquid crystal display, 4, charging port P1, 5, switch J4.

Detailed Description

The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the present invention more comprehensible to those skilled in the art, and will thus provide a clear and concise definition of the scope of the present invention.

Referring to fig. 1 to 3, an embodiment of the present invention includes:

the utility model provides a can take rectifier module to measure breaker divide-shut brake coil direct resistance instrument, includes

casing

1, and 1 surface of casing is equipped with a plurality of buttons 2, liquid crystal display 3, is equipped with battery, test circuit board in the

casing

1, and 1 side of casing is equipped with charge mouth 4(P1), switch 5(J4), and switch 5(J4) are total switch. The testing circuit board comprises a power supply module of the testing circuit board, a constant current and signal conditioning module connected with the output end of the power supply module, a CPU and a sampling module. The power supply module is powered by a battery, converts the voltage of the battery into +/-15V and +/-3.3V and respectively supplies power to the constant current and signal conditioning module, the CPU and the sampling module; the constant current and signal conditioning circuit is connected with the CPU and the sampling module and is used for providing various constant current and conditioning voltage signals; the CPU and the sampling module are used for controlling the detection of the external interface and the electric quantity of the battery. The test circuit board further comprises a key circuit and a liquid crystal display circuit, the key circuit and the liquid crystal display circuit are both connected with the CPU, and the power supply module provides +5V voltage for the liquid crystal display circuit.

With reference to fig. 4, the power supply module includes a switch J4, an isolated power supply chip J6, a 3.3V voltage conversion circuit, and a 5V voltage conversion circuit. Preferably, the power module is powered by a 12.6V lithium battery, the lithium battery is mounted through a battery holder J5, a charging port P1 is arranged on one side of the battery holder J5, a switch J4 is arranged, and the voltage of the lithium battery is shunted through a switch J4. The isolation power supply chip J6 adopts WRE1215S-3WR2, and is an isolation voltage-stabilizing positive-negative dual-path output DC/DC module power supply with power of 3W and wide-voltage 18V input. The power module generates positive and negative 15V voltage for the constant current and signal conditioning module through WRE1215S-3WR2 chip J6.

The 3.3V voltage conversion circuit comprises a linear voltage stabilizing chip U7, capacitors C8, C9, polar capacitors C15 and C16, wherein the capacitor C8 is connected with the polar capacitor C15 in parallel and then is respectively connected with a port Vin of U7 and GND, the capacitor C9 is connected with the polar capacitor C16 in parallel and then is respectively connected with a port Vout of U7 and GND, and circuit components and connection relations thereof are shown in the figure. Preferably, AS1117 is adopted AS the linear voltage regulation chip U7.

The 5V voltage conversion circuit comprises a voltage reduction chip U6, capacitors C7, C14, an electrolytic capacitor C13, a diode D1 and an inductor L1. The circuit components and their connections are shown in the figure. Preferably, the BUCK chip U6 is an LM2596 switch type BUCK BUCK chip U6. The power supply module is divided into a group of voltage circuits, the group of voltage circuits is used for reducing and stabilizing the power supply voltage to 5V through a voltage reduction chip U6, and the voltage provides working voltage for a liquid crystal display for display; in addition, the power module can divide a group of 5V voltage into 3.3V voltage by the linear voltage stabilizing chip U7 to supply power for the CPU and the sampling module.

With reference to fig. 5, the constant current and signal conditioning module includes a constant current driving circuit, a current detection circuit, and a voltage detection circuit, all connected to the CPU, and the power supply module provides 12V voltage for the constant current driving circuit and ± 15V voltage for the voltage detection circuit.

The constant current driving circuit comprises a MAX333 chip U5, a linear constant current chip U1, a resistor R1, a capacitor C1 and resistors R6-R9, and circuit components and connection relations thereof are shown in the figure. The MAX333 chip U5 and the resistors R1, R6-R9 form a current step switching circuit for providing various constant currents. The R1 has the function of ensuring that the RS end of the U1 is not suspended in the gear cutting process, and ensuring that the constant current chip can work normally all the time. The chip U5 is turned on by selecting different resistances through MAX333, and is matched with R1, so that U1 outputs a specified current value. In the use process, the states of four IO ports of P0.6, P0.7, P1.0 and P1.1 of the CPU are only required to be changed to realize various current gear combinations so as to be suitable for ensuring that the voltage values at two ends of the resistor are in an ideal measured range when the measured resistor in different ranges is measured. Preferably, the linear constant current chip U1 adopts DW8502, the DW8502 linear constant current chip U1 has few peripheral devices, the operation is simple, the single chip can realize constant current, and the constant current output size can be changed by only changing the resistance of the two pins to the ground.

The current detection circuit comprises a current sampling chip U3, a resistor R2 and a capacitor C3, wherein two ends of the resistor R2 are respectively connected with input and output pins-IN and + IN of the U3, and 12V voltage is input into the input pin + IN. The circuit components and their connection are shown in the figure. Preferably, the current sampling chip U3 adopts I282A, and the signal at the current sampling input end of the current sampling chip U3 can work higher than the power supply voltage of the chip, and is more suitable for the working condition of the current sampling resistor at the high-voltage end.

The voltage detection circuit comprises an AD620 high-precision instrument amplifier U4, capacitors C4 and C6 and is used for conditioning voltage signals. The circuit components and their connections are shown in the figure. The AD620 high-precision instrument amplifier U4 has the characteristics of differential input, low offset voltage, high precision and low offset drift, and is used for conditioning voltage signals.

In addition, the constant current and signal conditioning module further comprises a current output and voltage input terminal J7, and the current output and voltage input terminal J7 adopts a 4-wire resistance measurement mode, so that errors caused by test wires are effectively reduced.

Referring to fig. 6, the CPU and sampling module includes a CPU, a reset circuit connected to the CPU, a battery level detection circuit, a liquid crystal interface J3, and a keyboard interface J2. The circuit components and their connections are shown in the figure. Preferably, the CPU adopts a C8051F850 control chip U2 as a control core, and the control chip is provided with a 12-bit AD. The reset circuit is composed of a source crystal oscillator Y1, a debugging interface J1, resistors R3 and R4, capacitors C5 and C11. The keyboard interface J2 determines that one group of keys is pressed by detecting the level states of six port lines P1.2, P1.3, P1.4, P1.5, P1.6 and P1.7 of the CPU, and the liquid crystal interface J3 is connected with the single chip microcomputer through a serial port.

The battery capacity detection circuit comprises resistors R10 and R11, wherein one ends of R10 and R11 are connected in parallel and then connected with a port P0.2 of a CPU, the other end of R10 is connected with battery voltage, and the other end of R11 is grounded. The voltage of the battery is divided by the resistors and then is connected to an A/D conversion circuit of the singlechip through P0.2 to detect the electric quantity of the battery.

The circuit principle of the instrument is as follows: the lithium battery of the power supply module can respectively output voltages of +5V, 3.3V, 12V and +/-15V through the switch J4, the voltage of the battery output by the lithium battery is reduced to 5V through the LM2596 switch type BUCK voltage reduction chip U6 to supply power for the liquid crystal display, the LM2596 switch type BUCK voltage reduction chip U6 is a switch voltage reduction circuit, and the efficiency can reach more than 85%. The +5V voltage of output later steps down to 3.3V through linear voltage regulation chip U7 and supplies power for the singlechip, because the singlechip is integrated AD converter, so the power supply needs the power supply of low ripple, and linear voltage regulation chip U7 can satisfy the demand of low ripple power supply. The 12V voltage output by the other group is converted into +/-15V power through the isolation power module chip J6 to supply power to provide positive and negative power for the voltage detection circuit chip AD620 high-precision instrumentation amplifier U4. The battery 12V directly supplies power to the constant current driving circuit, and in this way, the current can be better supplied to the constant current circuit.

During field test, the measuring lines of the instrument are connected, the measuring line clamps are respectively clamped at the opening and closing measuring heads of the aviation plug of the switch cabinet, the selection cursor is moved to the 'measuring' button on the liquid crystal display screen, the 'determining' button is clicked, and the measuring result can be displayed after waiting for several seconds. The test and the operation are simple, the rectification module does not need to be dismantled and restored, the measurement is directly carried out on the alternating current side of the rectification module, the test time is greatly reduced, the accident that equipment is damaged due to misoperation in the circuit breaker dismounting process is avoided to the greatest extent, and the controllability of site safety is improved.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes performed by the present invention or directly or indirectly applied to other related technical fields are included in the scope of the present invention.

Claims

1. An instrument capable of measuring direct resistance of a switching-on and switching-off coil of a circuit breaker with a rectification module is characterized by comprising a shell, wherein the surface of the shell is provided with a plurality of keys and a liquid crystal display screen, a battery and a test circuit board are arranged in the shell, and the test circuit board comprises a power supply module, a constant current and signal conditioning module, a CPU and a sampling module, wherein the constant current and signal conditioning module is connected with the output end of the power supply module;

the power supply module is powered by a battery, converts the voltage of the battery into +/-15V and +/-3.3V and respectively supplies power for the constant current and signal conditioning module, the CPU and the sampling module, and comprises a switch J4, an isolation power supply chip J6, a 3.3V voltage conversion circuit and a 5V voltage conversion circuit;

2. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module as claimed in claim 1, wherein the side of the casing is provided with a charging port, and the switch J4 is also arranged on the side of the casing.

3. The apparatus for measuring the direct resistance of the opening and closing coil of the circuit breaker according to claim 1, wherein the test circuit board further comprises a key circuit and a liquid crystal display circuit, the key circuit and the liquid crystal display circuit are both connected with the CPU, and the power module provides +5V voltage for the liquid crystal display circuit.

4. The apparatus for measuring the direct resistance of the opening and closing coil of the circuit breaker by the aid of the module with the rectifier according to claim 1, wherein the 3.3V voltage conversion circuit comprises a linear voltage stabilizing chip U7, capacitors C8, C9, polar capacitors C15 and C16, the capacitors C8 and the polar capacitors C15 are connected in parallel and then respectively connected with a port Vin and GND of the U7, and the capacitors C9 and the polar capacitors C16 are connected in parallel and then respectively connected with a port Vout and GND of the U7.

5. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module as claimed in claim 1, wherein the 5V voltage conversion circuit comprises a voltage reduction chip U6, capacitors C7 and C14, an electrolytic capacitor C13, a diode D1 and an inductor L1.

6. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module as claimed in claim 1, wherein the power module provides 12V voltage for the constant current driving circuit and ± 15V voltage for the voltage detection circuit.

7. The apparatus for measuring the direct resistance of the opening and closing coil of the circuit breaker according to claim 1, wherein the constant current driving circuit comprises a MAX333 chip U5, a linear constant current chip U1, a resistor R1, a capacitor C1, and resistors R6-R9, and the MAX333 chip U5, the resistors R1, R6-R9 form a current gear switching circuit for providing various constant currents.

8. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module as claimed in claim 1, wherein the voltage detection circuit comprises an AD620 high-precision instrument amplifier U4, and capacitors C4 and C6 for conditioning voltage signals.

9. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module as claimed in claim 1, wherein the battery capacity detection circuit comprises resistors R10 and R11, one ends of R10 and R11 are connected in parallel and then connected with a port P0.2 of a CPU, the other end of R10 is connected with a battery voltage, and the other end of R11 is grounded.

10. The apparatus for measuring direct resistance of opening and closing coils of circuit breakers with the rectification module according to claim 1 or 9, wherein the CPU adopts a micro control chip C8051F 850.