CN112014784A - Full-automatic calibrating device of residual current operated protective device operating characteristic detector - Google Patents
Full-automatic calibrating device of residual current operated protective device operating characteristic detector Download PDFInfo
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- CN112014784A CN112014784A CN202010974333.XA CN202010974333A CN112014784A CN 112014784 A CN112014784 A CN 112014784A CN 202010974333 A CN202010974333 A CN 202010974333A CN 112014784 A CN112014784 A CN 112014784A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/005—Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
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Abstract
The invention discloses a full-automatic calibration device for an operating characteristic detector of a residual current operated protector, which comprises a measurement interface, a current sampler, an amplification filter circuit, a range switching unit, a high-speed ADC chip, a CPU processing unit, a high-speed switch, an LTE radio frequency module and a touch liquid crystal display. The calibration device changes the traditional calibration mode, realizes automatic data transmission and automatic generation of a certificate report through the LTE network technology, reduces the participation of personnel in the calibration process, greatly improves the detection efficiency and realizes wireless network data transmission; the calibration device measures parameters such as residual current, residual current breaking time and the like of the residual current operated protector action characteristic detector, analyzes and processes measured original data, automatically generates original records meeting the requirements according to the requirements of national calibration standards, and realizes the functions of automatic detection and automatic data analysis and processing.
Description
Technical Field
The invention relates to the field of product detection and calibration, in particular to a full-automatic calibration device for an operating characteristic detector of a residual current operated protector.
Background
The residual current operated protector (RCD for short) is arranged in a low-voltage power grid, so that personal electric shock, electric fire and damage of electrical equipment can be effectively prevented, and the residual current operated protector is calibrated regularly (such as during annual safety inspection) in order to comprehensively master the running condition of the residual current operated protector. At present, the conventional calibration device of the residual current operated protector operating characteristic detector is widely used at home and abroad, and the conventional calibration device has the following problems:
1. the function is single, the operation is more complicated, the detection efficiency is lower, and the wireless network data transmission cannot be realized;
2. the existing device is easy to influence the calibration result by external factors, and the reliability of the measurement result is low.
Disclosure of Invention
The invention aims to provide a full-automatic calibration device for an operating characteristic detector of a residual current operated protector, aiming at the defects. The calibration device changes the traditional calibration mode, realizes automatic data transmission and automatic generation of a certificate report through the LTE network technology, reduces the participation of personnel in the calibration process, greatly improves the detection efficiency and realizes wireless network data transmission; the calibration device measures parameters such as residual current, residual current breaking time and the like of the residual current operated protector action characteristic detector, analyzes and processes measured original data, automatically generates original records meeting the requirements according to the requirements of national calibration standards, and realizes the functions of automatic detection and automatic data analysis and processing.
The technical scheme of the invention is as follows:
the invention provides a full-automatic calibrating device for an operating characteristic detector of a residual current operated protector, which comprises a measuring interface, a current sampler, an amplifying and filtering circuit, a range switching unit, a high-speed ADC chip, a CPU (central processing unit), a high-speed switch, an LTE (long term evolution) radio frequency module and a touch liquid crystal display, wherein the measuring interface is connected with the current sampler; the signal input end of the measurement interface is connected to the signal output end of the equipment to be calibrated, the signal output end of the measurement interface is connected to the signal input end of the current sampler through the high-speed switch, the signal output end of the current sampler is connected to the signal input end of the range switching unit through the amplification filter circuit, the signal output end of the range switching unit is connected to the signal input end of the high-speed ADC chip, the high-speed ADC chip is connected to the CPU, the signal output end of the CPU is connected to the LTE radio frequency module, and the LTE radio frequency module transmits original data analyzed and processed by the CPU processing unit to the terminal server; the touch liquid crystal display is connected with the CPU, and the signal output end of the CPU is also connected with the high-speed switch; the touch liquid crystal display transmits the calibration parameters to the CPU processing unit, and the calibration parameter signals are transmitted to the high-speed switch after being processed by the CPU processing unit.
Furthermore, the CPU processing unit comprises a singlechip minimum system circuit, and a USB-to-serial port circuit, a liquid crystal display interface circuit, a 4G communication module circuit, a data storage circuit and an audible and visual alarm circuit which are connected with the singlechip minimum system circuit.
Furthermore, the singlechip minimum system circuit comprises a singlechip chip, and a power circuit, a reset circuit, a clock circuit and an SWD download port which are connected with the singlechip chip.
Furthermore, the acousto-optic alarm circuit mainly comprises a light-emitting diode and a buzzer. When the input current exceeds the maximum rated value, the system gives out sound and light alarm; when the switching control switch is out of control, the voltage value is sampled by the sampling resistor for judgment, and at the moment, the system sends out audible and visual alarm.
Furthermore, a phase-locked frequency multiplication circuit is arranged between the range switching unit and the CPU processing unit, and the signal output end of the range switching unit is connected to the signal input end of the CPU processing unit through the phase-locked frequency multiplication circuit.
Further, the high-speed ADC chip is connected with a resistor divider. The data sampling rate of the high-speed ADC chip is up to 3MHZ, and the high-speed ADC chip can expand the dynamic range, expand the data rate and an internal fault monitor for energy monitoring, protection and control application. The input of the high-speed ADC chip is independently connected with the resistor voltage divider, and voltage or current can be measured through the transformer, so that the effective resolution can be improved to the maximum extent, and the requirement on measurement precision is met.
Further, the CPU processing unit is connected to a computer through a serial port communication interface. The serial communication interface is adopted to ensure the direct communication of data between the computer and the CPU processing unit.
Furthermore, a power supply is arranged on the calibration device, and the power supply comprises an analog circuit and a digital circuit. The power supply is carried out independently, the power supply of the analog circuit and the power supply of the digital circuit are isolated by adopting an optical coupling isolation mode, and the problem of interference between system signals is solved.
Further, a signal indicator lamp is arranged on the calibration device and is directly connected to the CPU processing unit. The signal indicator lamp mainly has the following functions: the POWER indicator light represents the POWER supply of the device, and the starting lamp is on; TXD and RXD pilot lamp represent the state that this apparatus communicates with computer, RXD is the data receiving pilot lamp of communication, TXD is the data transmitting pilot lamp of communication; the ALARM indicating lamp represents the ALARM state of the device, and the ALARM lamp is lightened when the measuring current exceeds the measuring range.
Furthermore, the touch liquid crystal display has storage capacity, the picture menu is convenient to realize, and meanwhile, the space of the single chip microcomputer can be saved. The high-speed switch is a high-speed switch with the precision of 10 ns. Because the device needs to measure the tripping time, namely the time difference between the input signal and the tripping cut-off, the high-speed switch can reduce the measurement error of the time, and because the measurement time is accurate to 100us, if a common relay is selected as the switch, the requirement cannot be met, the high-speed switch with the accuracy of 10ns is selected.
The invention has the beneficial effects that:
(1) the calibration device provided by the invention changes the traditional calibration mode, transmits the compiled original record to the headquarter terminal server through the LTE network technology, and the server automatically generates a corresponding certificate report, so that the work of 'Internet + metering calibration' is finally realized, the participation of personnel is reduced in the calibration process, the detection efficiency is greatly improved, and the wireless network data transmission is realized.
(2) The output end of the calibrated device is connected with the measuring interface of the calibrating device by a lead, a calibrating person can set the parameters of the calibrating device by touching the liquid crystal display, measure the parameters of residual current, residual current breaking time and the like of the residual current operated protector motion characteristic detector, analyze and process the measured original data, automatically generate original records meeting the requirements according to the requirements of national calibration standards, and realize the functions of automatic detection and automatic data analysis and processing.
Drawings
Fig. 1 shows a schematic diagram of an internal structure of a fully automatic calibration device for an operation characteristic detector of a residual current operated protector according to the present invention.
Fig. 2 shows a minimum system circuit diagram of a single chip microcomputer of the full-automatic calibration device for the residual current operated protector operating characteristic detector.
Detailed Description
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
Referring to fig. 1, a full-automatic calibration device for an aftercurrent operation protector operating characteristic detector includes a measurement interface, a current sampler, an amplification filter circuit, a range switching unit, a high-speed ADC chip, a CPU processing unit, a high-speed switch, an LTE radio frequency module, and a touch liquid crystal display; the signal input end of the measurement interface is connected to the signal output end of the equipment to be calibrated, the signal output end of the measurement interface is connected to the signal input end of the current sampler through the high-speed switch, the signal output end of the current sampler is connected to the signal input end of the range switching unit through the amplification filter circuit, the signal output end of the range switching unit is connected to the signal input end of the high-speed ADC chip, the high-speed ADC chip is connected to the CPU, the signal output end of the CPU is connected to the LTE radio frequency module, and the LTE radio frequency module transmits original data analyzed and processed by the CPU processing unit to the terminal server; the touch liquid crystal display is connected with the CPU, and the signal output end of the CPU is also connected with the high-speed switch; the control liquid crystal display transmits the calibration parameters to the CPU processing unit, and the calibration parameter signals are transmitted to the high-speed switch after being processed by the CPU processing unit.
The CPU processing unit mainly comprises a singlechip minimum system circuit, a USB-to-serial port circuit, a liquid crystal display interface circuit, a 4G communication module circuit, a data storage circuit and an audible and visual alarm circuit; the USB-to-serial port circuit, the liquid crystal display interface circuit, the 4G communication module circuit, the data storage circuit and the sound-light alarm circuit are respectively connected to the minimum system circuit of the single chip microcomputer. The CPU processing unit can manage each hardware unit circuit in the calibration device and process the calculation detection data. As shown in fig. 2, the minimum system circuit of the single chip microcomputer includes a single chip microcomputer chip, a power circuit, a reset circuit, a clock circuit and an SWD download port; the single chip can better and faster execute the current algorithm in the calibration device. The acousto-optic alarm circuit mainly comprises a light emitting diode and a buzzer. When the input current exceeds the maximum rated value, the system gives out sound and light alarm; when the switching control switch is out of control, the voltage value is sampled by the sampling resistor for judgment, and at the moment, the system sends out audible and visual alarm.
The single chip microcomputer power supply circuit mainly supplies power to the single chip microcomputer chip, the power supply is connected with pins VDD and VSS of the single chip microcomputer, and the power supply voltage is 3.3V direct current. The singlechip can work only after being electrified and needs to be reset, a power-on reset circuit formed by a resistor and a capacitor is used in the project, and a reset signal is connected with an NRST pin of the singlechip. The clock circuit is composed of a passive crystal oscillator and a capacitor and is connected with the OSCIN and OSCOUT pins of the singlechip. The downloading circuit adopts an SWD form and is respectively connected with VDD, VSS, SWCLK and SWDIO of the single chip microcomputer, wherein the SWCLK is a clock signal, and the SWDIO is a data signal.
And a phase-locked frequency multiplication circuit is arranged between the range switching unit and the CPU processing unit, and the signal output end of the range switching unit is connected to the signal input end of the CPU processing unit through the phase-locked frequency multiplication circuit.
The high-speed ADC chip is connected with the resistor divider. The data sampling rate of the high-speed ADC chip is up to 3MHZ, and the high-speed ADC chip can expand the dynamic range, expand the data rate and an internal fault monitor for energy monitoring, protection and control application. The input of the high-speed ADC chip is independently connected with the resistor voltage divider, and voltage or current can be measured through the transformer, so that the effective resolution can be improved to the maximum extent, and the requirement on measurement precision is met.
The CPU processing unit is connected to a computer through a serial port communication interface. The serial communication interface is adopted to ensure the direct communication of data between the computer and the CPU processing unit.
The calibration device is provided with a power supply, and the power supply comprises an analog circuit and a digital circuit. The power supply is carried out independently, the power supply of the analog circuit and the power supply of the digital circuit are isolated by adopting an optical coupling isolation mode, and the problem of interference between system signals is solved.
And a signal indicator lamp is arranged on the calibration device and is directly connected to the CPU processing unit. The signal indicator lamp mainly has the following functions: the POWER indicator light represents the POWER supply of the device, and the starting lamp is on; TXD and RXD pilot lamp represent the state that this apparatus communicates with computer, RXD is the data receiving pilot lamp of communication, TXD is the data transmitting pilot lamp of communication; the ALARM indicating lamp represents the ALARM state of the device, and the ALARM lamp is lightened when the measuring current exceeds the measuring range.
The touch liquid crystal display 1 has storage capacity, the picture menu is convenient to realize, and meanwhile, the space of a single chip microcomputer can be saved.
The high-speed switch is a high-speed switch with the precision of 10 ns. Because the device needs to measure the tripping time, namely the time difference between the input signal and the tripping cut-off, the high-speed switch can reduce the measurement error of the time, and because the measurement time is accurate to 100us, if a common relay is selected as the switch, the requirement cannot be met, the high-speed switch with the accuracy of 10ns is selected.
The working process of the full-automatic calibrating device for the residual current operated protector operating characteristic detector is as follows:
s1, connecting a signal output end of the residual current operated protector operating characteristic detector to be calibrated with a measurement interface of a calibration device through a lead, setting calibration device parameters through a touch liquid crystal display by a calibrator, transmitting the calibration parameters to a CPU (central processing unit) through the touch liquid crystal display, and transmitting calibration parameter signals to a high-speed switch after the calibration processing of the CPU; meanwhile, the measurement interface transmits instantaneous current signals output by the residual current action protector action characteristic detector to the high-speed switch, and the high-speed switch transmits the signals to the current sampler, so that the instantaneous current signals output by the corrected residual current action protector action characteristic detector are collected and input; wherein the calibration process is as follows: after receiving the calibration current and the command of starting calibration, the CPU processing unit switches the range gear according to the magnitude of the calibration current, simultaneously turns on the high-speed switch, then measures the current provided by the standard source, calculates the current conversion coefficient K according to the current data provided by the standard source, and finishes calibration after the calculation of the K is finished.
S2, the instantaneous current signal collected by the current sampler is amplified and filtered by the amplified current filter circuit 3, so that the precision of the alternating current is improved;
s3, inputting the amplified and filtered instantaneous current signal into a range switching unit, wherein the current signal output by the range switching unit has 24 bits, has anti-interference capacity and can be adjusted, so that the anti-interference processing of the instantaneous current signal is realized, and the current measurement resolution and precision are effectively improved;
s4, inputting the instantaneous current signal output by the range switching unit into a high-speed ADC chip (the data sampling rate is up to 3MHZ) and a phase-locked frequency doubling circuit respectively; the high-speed ADC chip collects current signals, 1024 current signals are adopted in one period, signals of each point in the 1024 current signals are instantaneous current signals, and sine wave signals are synthesized by fitting the 1024 current signals; the phase-locked frequency doubling circuit measures a waveform synchronous signal of instantaneous current and an AD measurement starting signal to realize waveform regeneration of the instantaneous current signal; meanwhile, the phase-locked frequency doubling circuit transmits a phase signal of the sine wave signal generated by the phase-locked frequency doubling circuit to the CPU processing unit, and displays a waveform image to be detected through the touch liquid crystal display; inputting sine wave signals to be synthesized by the high-speed ADC chip and further inputting the sine wave signals into the CPU processing unit; the high-speed ADC chip is independently and directly connected with the resistor voltage divider, voltage or current can be measured through the transformer, effective resolution can be improved to the maximum extent, and the requirement on measurement precision is met;
and S5, the CPU processing unit completes automatic detection of instantaneous current signal parameters, automatic analysis and calculation of detection data, and automatically generates an original record meeting the requirements according to the requirements of national calibration standards. The automatic measurement process comprises the following steps: the CPU processing unit can select gears according to set measuring current, wherein the current measurement of the calibration device is divided into three gears, and the three gears are controlled by a switching control switch (relay); after the gear is switched well (the gear is switched with a relay and a multi-channel selection circuit to be matched simultaneously, the gear switching can be completed), the CPU processing unit controls the high-speed switch to be switched on, signals are sent to an amplifying and filtering circuit-a phase-locked frequency doubling circuit and an AD measuring circuit of a high-speed ADC chip-the CPU processing unit continuously reads the measured data of the high-speed ADC chip, the read data are waveforms completed by a plurality of alternating current sine waves (the phase-locked frequency doubling circuit and a synchronous signal are matched to ensure that the measured data are complete sine wave signals), and then the CPU processing unit calculates the measured data to obtain the current value to be measured.
In the detection process, when the input instantaneous current signal exceeds the maximum rated value, the calibration device gives out sound-light alarm through the light-emitting diode and the buzzer; when the switching control switch (relay) is out of control, the sampling voltage value of the sampling resistor in the calibration device is used for judgment, and the calibration device also gives out sound and light alarm at the moment.
And S5, the CPU transmits the generated original record to the original record detection data packet through the LTE radio frequency module under the condition of LTE mobile network coverage, and sends the original record detection data packet to the terminal server, and automatically generates a certificate report on the terminal server to complete the work of 'Internet + metering calibration'.
The device is also provided with a time measuring unit which is realized by adopting a CPLD mode. The single chip microcomputer STM32 sends time interval data to the CPLD chip, the CPLD chip waits for an external input signal after receiving the data, the first rising edge of the external signal triggers a time measuring program, when the time count is equal to the time interval data sent by the STM32, the CPLD sends a SWITCH signal to the high-speed MOS tube, the external signal is cut off, and the switching process of the simulated leakage protector is achieved.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed.
Claims (9)
1. A full-automatic calibration device for an operating characteristic detector of a residual current operated protector is characterized by comprising a measuring interface, a current sampler, an amplifying and filtering circuit, a range switching unit, a high-speed ADC chip, a CPU processing unit, a high-speed switch, an LTE radio frequency module and a touch liquid crystal display; the signal input end of the measurement interface is connected to the signal output end of the equipment to be calibrated, the signal output end of the measurement interface is connected to the signal input end of the current sampler through the high-speed switch, the signal output end of the current sampler is connected to the signal input end of the range switching unit through the amplification filter circuit, the signal output end of the range switching unit is connected to the signal input end of the high-speed ADC chip, the high-speed ADC chip is connected to the CPU, the signal output end of the CPU is connected to the LTE radio frequency module, and the LTE radio frequency module transmits original data analyzed and processed by the CPU processing unit to the terminal server; the touch liquid crystal display is connected with the CPU, and the signal output end of the CPU is also connected with the high-speed switch; the touch liquid crystal display transmits the calibration parameters to the CPU processing unit, and the calibration parameter signals are transmitted to the high-speed switch after being processed by the CPU processing unit.
2. The full-automatic calibration device for the residual current operated protector operating characteristic detector according to claim 1, wherein the CPU processing unit comprises a single chip microcomputer minimum system circuit, and a USB to serial port circuit, a liquid crystal display interface circuit, a 4G communication module circuit, a data storage circuit, and an audible and visual alarm circuit connected thereto.
3. The device for automatically calibrating the motion characteristic detector of the residual current operated protector according to claim 2, wherein the minimum system circuit of the single chip microcomputer comprises a single chip microcomputer chip, and a power circuit, a reset circuit, a clock circuit and an SWD download port which are connected with the single chip microcomputer chip.
4. The device for automatically calibrating the residual current operated protector operating characteristic detector according to claim 2, wherein the audible and visual alarm circuit comprises a light emitting diode and a buzzer.
5. The full-automatic calibration device for the residual current operated protector operating characteristic detector according to claim 1, wherein a phase-locked frequency doubling circuit is arranged between the range switching unit and the CPU processing unit, and a signal output end of the range switching unit is connected to a signal input end of the CPU processing unit through the phase-locked frequency doubling circuit.
6. The device for automatically calibrating the motion characteristic detector of the residual current operated protector according to claim 1, wherein the high-speed ADC chip is connected with a resistor voltage divider.
7. The device for automatically calibrating the motion characteristic detector of the residual current operated protector according to claim 1, wherein the CPU processing unit is connected to a computer through a serial communication interface.
8. The device of claim 1, wherein the calibration device is provided with a power supply for supplying power to the circuits.
9. The device for automatically calibrating the motion characteristic detector of the residual current operated protector according to claim 1, wherein a signal indicator lamp is arranged on the calibrating device, and the signal indicator lamp is directly connected to the CPU processing unit.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112578278A (en) * | 2020-12-16 | 2021-03-30 | 河南省计量科学研究院 | Residual current protector action characteristic tester calibration device and system algorithm |
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2020
- 2020-09-16 CN CN202010974333.XA patent/CN112014784A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112578278A (en) * | 2020-12-16 | 2021-03-30 | 河南省计量科学研究院 | Residual current protector action characteristic tester calibration device and system algorithm |
| CN112578278B (en) * | 2020-12-16 | 2024-05-31 | 河南省计量测试科学研究院 | Calibration method of residual current protector action characteristic tester calibration device |
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