CN216117834U

CN216117834U - Handheld transformer no-load loss test circuit

Info

Publication number: CN216117834U
Application number: CN202122077700.9U
Authority: CN
Inventors: 袁松; 王聪; 李学伍
Original assignee: Wuhan Deya Electric Power Technology Co ltd
Current assignee: Wuhan Deya Electric Power Technology Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-03-22
Anticipated expiration: 2031-08-31

Abstract

The utility model provides a handheld transformer no-load loss test circuit, which comprises an ARM control unit, a data acquisition module, a real-time clock module, a key module, a data storage module, a touch screen module and a battery module, wherein the ARM control unit is used for controlling the ARM control unit to acquire data; the input end of the data acquisition unit is electrically connected with the secondary side of the transformer, and the output end of the data acquisition unit is electrically connected with the ARM control unit; the output end of the real-time clock module is electrically connected with the ARM control unit; the key module, the data storage module and the touch screen module are respectively electrically connected with the ARM control unit; the battery module is respectively used for supplying power for the ARM control unit, the data acquisition module, the real-time clock module, the key module, the data storage module and the touch screen module.

Description

Handheld transformer no-load loss test circuit

Technical Field

The utility model relates to the technical field of transformer performance parameter detection equipment, in particular to a handheld transformer no-load loss test circuit.

Background

The transformer no-load test is a method for measuring the electrical parameters of the single-phase or three-phase power transformer, such as the effective value of alternating voltage, the average value of voltage, the effective value of voltage, active power, power factor and the like.

Common transformer air load test equipment is suitcase type structure, and is bulky and weight is big, leads to it to carry and use convenience inadequately. In view of the above disadvantages, it is necessary to develop a portable and reliable test circuit for testing the empty load loss and a corresponding tester, so as to improve the convenience of measurement.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a handheld transformer no-load loss test circuit with compact structure, convenient carrying and high integration level.

The technical scheme of the utility model is realized as follows: the utility model provides a handheld transformer no-load loss test circuit which comprises an ARM control unit (1), a data acquisition module (2), a real-time clock module (3), a key module (4), a data storage module (5), a touch screen module (6) and a battery module (7); the input end of the data acquisition unit is electrically connected with the secondary side of the transformer, and the output end of the data acquisition unit is electrically connected with the ARM control unit (1); the output end of the real-time clock module (3) is electrically connected with the ARM control unit (1); the key module (4), the data storage module (5) and the touch screen module (6) are respectively electrically connected with the ARM control unit (1); the battery module (7) is used for supplying power for the ARM control unit (1), the data acquisition module (2), the real-time clock module (3), the key module (4), the data storage module (5) and the touch screen module (6) respectively;

the data acquisition module (2) is used for acquiring voltage signals or current signals of phase lines on the secondary side of the transformer and sending the voltage signals and the current signals into the ARM control unit (1); the real-time clock module (3) provides current real-time information and inputs the current real-time information into the ARM control unit (1), the key module (4) and the touch screen module (6) can perform input, and the touch screen module (6) can perform output display; and the data storage module (5) stores the voltage signal, the current signal and the current real-time information acquired by the ARM control unit (1).

On the basis of the above technical solution, preferably, the data acquisition module (2) includes three groups of voltage sampling units, three groups of current sampling units, and a metering unit U1; the voltage sampling unit acquires a single-phase voltage signal from the transformer and inputs the single-phase voltage signal into the metering unit U1, and the current sampling unit acquires a single-phase current signal from the transformer and inputs the single-phase current signal into an input channel of the metering unit U1; the ARM control unit (1) comprises a plurality of SPI serial interfaces, IIC interfaces and universal input and output interfaces; the output end of the metering unit U1 is electrically connected with an SPI serial interface of the ARM control unit (1) in a one-to-one correspondence manner.

Preferably, each voltage sampling unit comprises a current transformer, a first sampling resistor, a first RC parallel filter circuit and a second RC parallel filter circuit; two ends of the first sampling resistor are respectively and electrically connected with two output ends of the current transformer; one end of the first sampling resistor is electrically connected with the input end of the first RC parallel filter circuit, the other end of the first sampling resistor is electrically connected with the input end of the second RC parallel filter circuit, and the output end of the first RC parallel filter circuit and the output end of the second RC parallel filter circuit are correspondingly and electrically connected with one group of input channels of the metering unit U1; each current sampling unit all includes divider resistance, the second sampling resistance, third RC parallel filter circuit and the parallel filter circuit of fourth RC, divider resistance's one end and the phase line electric connection of transformer, divider resistance's the other end and the one end of second sampling resistance and the parallel filter circuit's of third RC input electric connection, the other end of second sampling resistance respectively with transformer central line and the parallel filter circuit's of fourth RC input electric connection, the parallel filter circuit's of third RC output and the parallel filter circuit's of fourth RC output and another group's input channel of measurement unit U1 correspond electric connection.

Preferably, the real-time clock module (3) includes an RTC chip U2, and an output terminal of the RTC chip U2 is electrically connected to an IIC interface of the ARM control unit (1) in a one-to-one correspondence manner; the power end of the RTC chip U2 is electrically connected with the battery module (7).

Preferably, the KEY module (4) comprises a plurality of KEY KEYs, one end of each KEY is electrically connected with a general input/output interface and a +3.3V power supply of the ARM control unit (1), and the other end of each KEY is grounded.

Preferably, the DATA saving module (5) includes a TF card slot U3, and the command response port CMD, the clock signal port CLK and the DATA transmission port DATA of the TF card slot U3 are electrically connected with the general input/output interfaces PD2, PC12, PC8, PC9, PC10 and PC11 of the ARM control unit (1) in a one-to-one correspondence manner.

Preferably, the touch screen module (6) comprises a touch screen and a driving chip U4, wherein the positive input end of the touch screen is electrically connected with the pin 2 and the pin 3 of the driving chip U4, and the negative input end of the touch screen is electrically connected with the pin 4 and the pin 5 of the driving chip U4;

pins

11 and 13 of the driving chip U4 are electrically connected with the general input/output interface of the ARM control unit (1) in a one-to-one correspondence manner; and the

pins

12, 14, 15 and 16 of the driver chip U4 are electrically connected with the other SPI serial interface of the ARM control unit (1) in a one-to-one correspondence manner.

Preferably, the battery module (7) comprises a charging chip U5 and a lithium battery BAT, a pin 4 of the charging chip U5 is connected with an external USB charging interface, and the pin 4 is further electrically connected with a pin 1 through a resistor R48 and a light emitting diode LED1 which are sequentially arranged; pin 3 of the charging chip U5 is electrically connected to the positive electrode of the lithium battery BAT.

Preferably, the metering unit U1 is a three-phase electric energy metering chip ATT7022 EU.

Compared with the prior art, the handheld transformer air load loss test circuit provided by the utility model has the following beneficial effects:

(1) according to the utility model, by configuring the ARM control unit with high integration level, the data acquisition module, the real-time clock module, the key module, the data storage module and the touch screen module, multiple functions of data acquisition, universal time recording, key or touch input and display output are realized, the volume of a circuit board is greatly optimized, and the weight and the volume of the transformer empty load test equipment are greatly reduced on the premise of ensuring the measurement reliability;

(2) the data acquisition module samples each phase voltage and current of the transformer respectively, inputs analog signals of positive and negative half cycles into corresponding input ports of the metering unit after filtering, and the metering unit automatically calculates active power, reactive power, apparent power, power factor, phase angle, effective value of voltage or effective value of current and outputs the result to the ARM control unit;

(3) the real-time clock module can accurately provide world time, and is continuously powered by the lithium battery, so that the accuracy of the measured time and the reliability of calculation of the metering unit are ensured;

(4) the key module, the data storage module or the touch screen module can better realize corresponding functions of data input, data output or data storage and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of a circuit for testing an empty load loss of a hand-held transformer according to the present invention;

FIG. 2 is a wiring diagram of a data acquisition module of an air load loss test circuit of a hand-held transformer according to the present invention;

FIG. 3 is a wiring diagram of a real-time clock module of an air load loss test circuit of a hand-held transformer according to the present invention;

FIG. 4 is a wiring diagram of a key module of the no-load loss testing circuit of the hand-held transformer according to the present invention;

FIG. 5 is a wiring diagram of a data retention module of a hand-held transformer no-load loss test circuit of the present invention;

FIG. 6 is a wiring diagram of a touch screen module of a hand-held transformer no-load loss test circuit according to the present invention;

fig. 7 is a wiring diagram of a battery module of a hand-held transformer no-load loss test circuit according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, a diagram shows a handheld transformer no-load loss test circuit, which includes an ARM control unit 1, a data acquisition module 2, a real-time clock module 3, a key module 4, a data storage module 5, a touch screen module 6, and a battery module 7; the input end of the data acquisition unit is electrically connected with the secondary side of the transformer, and the output end of the data acquisition unit is electrically connected with the ARM control unit 1; the output end of the real-time clock module 3 is electrically connected with the ARM control unit 1; the key module 4, the data storage module 5 and the touch screen module 6 are respectively electrically connected with the ARM control unit 1; the battery module 7 respectively supplies power to the ARM control unit 1, the data acquisition module 2, the real-time clock module 3, the key module 4, the data storage module 5 and the touch screen module 6;

when the utility model is used, the data acquisition module 2 is used for acquiring voltage signals or current signals of each phase line on the secondary side of the transformer and sending the voltage signals and the current signals into the ARM control unit 1; the real-time clock module 3 provides current real-time information and inputs the current real-time information into the ARM control unit 1, the key module 4 and the touch screen module 6 can perform input, and the touch screen module 6 can also perform output display; and the data storage module 5 stores the voltage signal, the current signal and the current real-time information acquired by the ARM control unit 1. Due to the adoption of the chip with high integration level, the volume of the circuit board can be greatly reduced, so that the weight and the volume of the transformer empty load testing equipment are reduced, and the measurement convenience is improved on the premise of ensuring the measurement reliability.

As shown in fig. 2, the data acquisition module 2 includes three groups of voltage sampling units, three groups of current sampling units and a metering unit U1; the voltage sampling unit acquires a single-phase voltage signal from the transformer and inputs the single-phase voltage signal into the metering unit U1, and the current sampling unit acquires a single-phase current signal from the transformer and inputs the single-phase current signal into an input channel of the metering unit U1; the ARM control unit 1 comprises a plurality of SPI serial interfaces, IIC interfaces and universal input and output interfaces; the output end of the metering unit U1 is electrically connected with an SPI serial interface of the ARM control unit 1 in a one-to-one correspondence manner. In the utility model, the metering unit U1 is a three-phase electric energy metering chip ATT7022 EU. The ARM control unit 1 can be implemented by an STM32 series single chip microcomputer of an intentional semiconductor, and of course, similar controllers of other companies can be adopted, which are not described herein again.

Each voltage sampling unit comprises a current transformer, a first sampling resistor, a first RC parallel filter circuit and a second RC parallel filter circuit; two ends of the first sampling resistor are respectively and electrically connected with two output ends of the current transformer; one end of the first sampling resistor is electrically connected with the input end of the first RC parallel filter circuit, the other end of the first sampling resistor is electrically connected with the input end of the second RC parallel filter circuit, and the output end of the first RC parallel filter circuit and the output end of the second RC parallel filter circuit are correspondingly electrically connected with one group of input channels of the metering unit U1. Taking a voltage sampling unit for sampling the voltage of the phase a as an example, the voltage sampling unit outputs an alternating current signal by carrying out current mutual inductance on the phase a, converts the alternating current signal into an alternating voltage signal through a first sampling resistor R2, and divides the alternating voltage signal into two paths of alternating signals to be sent to a group of input channels of a metering unit U1 under the processing of a first RC parallel filter circuit consisting of a resistor R1 and a capacitor C1 and a second RC parallel filter circuit consisting of a resistor R3 and a capacitor C2. The effective value of two paths of alternating signals is 0.1 mV-0.5V, and the structures of other two groups of voltage sampling units are completely the same.

Each current sampling unit comprises a divider resistor, a second sampling resistor, a third RC parallel filter circuit and a fourth RC parallel filter circuit, one end of the divider resistor is electrically connected with a phase line of the transformer, the other end of the divider resistor is electrically connected with one end of the second sampling resistor and the input end of the third RC parallel filter circuit, the other end of the second sampling resistor is electrically connected with the center line of the transformer and the input end of the fourth RC parallel filter circuit respectively, and the output end of the third RC parallel filter circuit and the output end of the fourth RC parallel filter circuit are electrically connected with the corresponding input channel of the metering unit U1. Taking a current sampling unit for sampling phase-A current as an example, a voltage signal is directly obtained between a phase-A and a central line N, the voltage is higher, the voltage is divided by a divider resistor and then is sent to a third RC parallel filter circuit and a fourth RC parallel filter circuit by a second sampling resistor R14, two paths of alternating signals are output to the other group of input channels of the metering unit U1, and the effective value of the two paths of alternating signals is about 0.05V.

As shown in fig. 3, the real-time clock module 3 includes an RTC chip U2, and an output terminal of the RTC chip U2 is electrically connected to an IIC interface of the ARM control unit 1 in a one-to-one correspondence manner; the power terminal of the RTC chip U2 is electrically connected to the battery module 7. The RTC chip U2 of the utility model selects DS3231 SN.

As shown in fig. 4, the KEY module 4 includes a plurality of KEY KEYs, one end of each KEY is electrically connected to a general input/output interface of the ARM control unit 1 and the +3.3V power supply, and the other end of each KEY is grounded.

As shown in fig. 5, the DATA saving module 5 includes a TF card slot U3, and the command response port CMD, the clock signal port CLK and the DATA transmission port DATA of the TF card slot U3 are electrically connected to the general input/output interfaces PD2, PC12, PC8, PC9, PC10 and PC11 of the ARM control unit 1 in a one-to-one correspondence manner. The command response port CMD indicates the selection and operating state of the TF card slot U3.

As shown in fig. 6, the touch screen module 6 includes a touch screen and a driving chip U4, a positive input terminal of the touch screen is electrically connected to

pins

2 and 3 of the driving chip U4, and a negative input terminal of the touch screen is electrically connected to

pins

4 and 5 of the driving chip U4;

pins

11 and 13 of the driving chip U4 are electrically connected with the general input/output interface of the ARM control unit 1 in a one-to-one correspondence manner;

pins

12, 14, 15 and 16 of the driver chip U4 are electrically connected to another SPI serial interface of the ARM control unit 1 in a one-to-one correspondence manner. The touch screen module 6 can realize multi-point touch input through the touch screen and can also perform display output. It should be noted that the touch screen module 6 can not only implement display output, but also implement a touch input function, and in this case, the use of the key module 4 can be avoided; if the touch screen with the input function is not selected, the key module 4 is required to be used for data input.

As shown in fig. 7, the battery module 7 includes a charging chip U5 and a lithium battery BAT, the pin 4 of the charging chip U5 is connected to an external USB charging interface, and the pin 4 is further electrically connected to the pin 1 through a resistor R48 and a light emitting diode LED1 which are sequentially arranged; pin 3 of the charging chip U5 is electrically connected to the positive electrode of the lithium battery BAT. The input signal of the charging chip U5 is a direct current signal of 5V1A, and can be charged by a lithium battery BAT of 3.7-4.2V. The lithium battery BAT can further output +3.3V power supply to be used by each chip during working through the linear stabilized voltage power supply.

The chip according to the present invention is easily available, and a corresponding technical manual can be obtained at the same time as the chip is obtained, and the present invention does not involve any improvement in the procedure.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a hand-held type transformer no-load loss test circuit which characterized in that: the device comprises an ARM control unit (1), a data acquisition module (2), a real-time clock module (3), a key module (4), a data storage module (5), a touch screen module (6) and a battery module (7); the input end of the data acquisition unit is electrically connected with the secondary side of the transformer, and the output end of the data acquisition unit is electrically connected with the ARM control unit (1); the output end of the real-time clock module (3) is electrically connected with the ARM control unit (1); the key module (4), the data storage module (5) and the touch screen module (6) are respectively electrically connected with the ARM control unit (1); the battery module (7) is used for supplying power for the ARM control unit (1), the data acquisition module (2), the real-time clock module (3), the key module (4), the data storage module (5) and the touch screen module (6) respectively;

2. The circuit for testing the empty load loss of the hand-held transformer according to claim 1, wherein: the data acquisition module (2) comprises three groups of voltage sampling units, three groups of current sampling units and a metering unit U1; the voltage sampling unit acquires a single-phase voltage signal from the transformer and inputs the single-phase voltage signal into the metering unit U1, and the current sampling unit acquires a single-phase current signal from the transformer and inputs the single-phase current signal into an input channel of the metering unit U1; the ARM control unit (1) comprises a plurality of SPI serial interfaces, IIC interfaces and universal input and output interfaces; the output end of the metering unit U1 is electrically connected with an SPI serial interface of the ARM control unit (1) in a one-to-one correspondence manner.

3. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: each voltage sampling unit comprises a current transformer, a first sampling resistor, a first RC parallel filter circuit and a second RC parallel filter circuit; two ends of the first sampling resistor are respectively and electrically connected with two output ends of the current transformer; one end of the first sampling resistor is electrically connected with the input end of the first RC parallel filter circuit, the other end of the first sampling resistor is electrically connected with the input end of the second RC parallel filter circuit, and the output end of the first RC parallel filter circuit and the output end of the second RC parallel filter circuit are correspondingly and electrically connected with one group of input channels of the metering unit U1; each current sampling unit all includes divider resistance, the second sampling resistance, third RC parallel filter circuit and the parallel filter circuit of fourth RC, divider resistance's one end and the phase line electric connection of transformer, divider resistance's the other end and the one end of second sampling resistance and the parallel filter circuit's of third RC input electric connection, the other end of second sampling resistance respectively with transformer central line and the parallel filter circuit's of fourth RC input electric connection, the parallel filter circuit's of third RC output and the parallel filter circuit's of fourth RC output and another group's input channel of measurement unit U1 correspond electric connection.

4. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the real-time clock module (3) comprises an RTC chip U2, and the output end of the RTC chip U2 is electrically connected with an IIC interface of the ARM control unit (1) in a one-to-one correspondence manner; the power end of the RTC chip U2 is electrically connected with the battery module (7).

5. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the KEY module (4) comprises a plurality of KEY KEY, one end of each KEY KEY is electrically connected with a general input/output interface and a +3.3V power supply of the ARM control unit (1), and the other end of each KEY KEY is grounded.

6. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the DATA storage module (5) comprises a TF card slot U3, and a command response port CMD, a clock signal port CLK and a DATA transmission port DATA of the TF card slot U3 are respectively and electrically connected with general input/output interfaces PD2, PC12, PC8, PC9, PC10 and PC11 of the ARM control unit (1) in a one-to-one correspondence mode.

7. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the touch screen module (6) comprises a touch screen and a driving chip U4, wherein the positive input end of the touch screen is electrically connected with a pin 2 and a pin 3 of a driving chip U4, and the negative input end of the touch screen is electrically connected with a pin 4 and a pin 5 of a driving chip U4; pins 11 and 13 of the driving chip U4 are electrically connected with the general input/output interface of the ARM control unit (1) in a one-to-one correspondence manner; and the pins 12, 14, 15 and 16 of the driver chip U4 are electrically connected with the other SPI serial interface of the ARM control unit (1) in a one-to-one correspondence manner.

8. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the battery module (7) comprises a charging chip U5 and a lithium battery BAT, a pin 4 of the charging chip U5 is connected with an external USB charging interface, and the pin 4 is also electrically connected with a pin 1 through a resistor R48 and a light-emitting diode LED1 which are sequentially arranged; pin 3 of the charging chip U5 is electrically connected to the positive electrode of the lithium battery BAT.

9. The circuit for testing the empty load loss of the hand-held transformer according to claim 2, wherein: the metering unit U1 is a three-phase electric energy metering chip ATT7022 EU.