CN104237842A - Alternating voltage test verification device for verifying automatic single-phase kilowatt-hour meter production line - Google Patents

Abstract

The invention discloses an AC voltage test checking device for verifying an automatic single-phase electric energy meter assembly line, which includes an insulating shell; the insulating shell and its interior are connected through connection terminals; wherein, the insulating shell includes a resistor for sampling high-voltage input signals Voltage dividing sampling circuit, its output signal is transmitted to the measurement detection unit to measure the sampling voltage, the measurement detection unit communicates with the MCU unit through the SPI interface, and the measurement value is displayed on the display module controlled by the MCU unit; the power supply and its The management unit supplies power to the MCU unit and the measurement detection unit. The design of the invention is simple, intuitive and portable, which is convenient for operators to connect, test and read data, and can greatly improve the efficiency of withstand voltage testing.

Description

AC voltage test and verification device for calibrating automatic single-phase electric energy meter assembly line

technical field

The invention relates to an AC voltage test checking device for testing an automatic single-phase electric energy meter assembly line. the

Background technique

The withstand voltage tester is a measuring instrument, which is mainly used for the testing of electric meters, collectors, terminals and other equipment between power companies and between power supply companies and users. An important part of the withstand voltage performance of equipment such as terminals and terminals. In order to ensure that the on-site test work is carried out accurately and smoothly, the AC voltage test verification device is particularly important. the

At present, there is no accurate measuring instrument for testing the voltage withstand meter in the world and at home. The State Grid has higher requirements for the accuracy of the reliability test of the electric meter, and puts forward higher requirements for the accuracy of the AC withstand voltage meter. Moreover, the use of the national automatic assembly line is The AC voltage test verification device provides a large market space. the

The AC voltage test is a verification item stipulated in the National Metrology Verification Regulations JJG596-2012. The verification device must provide an AC test voltage of 2kV or 4kV during the test, and the test time is 1min. For the manual inspection of the AC voltage items of the electric energy meter one by one, it can be easily It is easy to judge and complete the test, but for the large-scale multi-meter automatic verification single-phase smart energy meter assembly line system, the regulations require that each meter should meet the specified test requirements. It is difficult to judge whether all the epitopes have been provided with test voltage, and there is no similar device in the world or in China at present. the

Contents of the invention

The main purpose of the present invention is to provide an AC voltage test verification device for automatic single-phase electric energy meter assembly line verification in order to solve the problem of checking the current device for performing AC voltage tests on multi-meter single-phase smart energy meters. the

In order to achieve the above object, the device of the present invention adopts the following technical solutions:

An AC voltage test and checking device for verifying an automatic single-phase electric energy meter assembly line, which includes an insulating shell; the insulating shell and its interior are connected through terminal blocks; wherein, the insulating shell includes a resistor divider sampling circuit for sampling high-voltage input signals , the output signal is transmitted to the measurement detection unit to measure the sampling voltage, the measurement detection unit communicates with the MCU unit through the SPI interface, and the measurement value is displayed on the display module controlled by the MCU unit; the power supply and its management unit are MCU Unit and measurement detection unit power supply. the

The MCU unit is also connected with the infrared communication unit, the storage unit, the key operation unit and the extension unit. the

The resistance voltage sampling circuit is composed of a plurality of 300K resistances connected in series in the circuit. the

The power supply and its management unit use a linear regulated power supply chip RP130N501D, and a reverse diode is added to the ground pin of the chip RP130N501D. the

The shape and structure size of the AC voltage test checking device is consistent with the size of the single-phase smart electric energy meter. the

The test voltage range of the AC voltage test checking device is 1000-5000V. the

The beneficial effects of the present invention are:

(1) For the first time, this device has realized the verification of the device for the AC voltage test of the multi-meter single-phase smart energy meter. The measurement voltage range is wide and the measurement accuracy of the device is high;

(2) The test data is recorded with events through the memory, and the events include the time of the test, the maximum voltage value, and the duration;

(3) The power supply of the device is simple, battery-powered, low power consumption, about 6mA, capable of recording more than 10,000 verification tests;

(4) The design of the device is light and simple, and it is easy to automatically connect, test, store and read data in the assembly line system, which improves the efficiency of the AC voltage test and has a good application and promotion prospect. the

Description of drawings

Fig. 1 is the block diagram of the working principle of the withstand voltage testing device of the present invention;

Fig. 2 is the resistance divider sampling circuit of the present invention;

Fig. 3 is metering detection unit circuit of the present invention;

Fig. 4 is the power supply circuit of the present invention;

Fig. 5 a) is the infrared sending unit of the present invention

Fig. 5 b) is the infrared receiving unit of the present invention;

Fig. 6 is the connection schematic diagram of the present invention;

Fig. 7 is the structural representation of analog single-phase electric energy meter of the present invention;

In the figure, A is the AC voltage test checking device of the present invention, B is the AC withstand voltage instrument; C is the output terminal of the high voltage side of the AC withstand voltage instrument, D is the output terminal of the low voltage side of the AC withstand voltage instrument, a, b, c, d, e and f are the strong current terminals of the AC voltage test and verification device, g, h, i, j, k and l are the weak current terminals of the AC voltage test and verification device, 1 is the high voltage signal input, and 2 is the resistance voltage dividing sampling circuit , 3 is a measurement detection unit, 4 is an MCU unit, 5 is an infrared communication unit, 6 is a display module, 7 is a storage unit, 8 is a key operation unit, 9 is an expansion unit, and 10 is a power supply and its management unit. the

Detailed ways

As shown in Figure 1, an AC voltage test and checking device for verifying an automated single-phase electric energy meter assembly line includes an insulating case; the insulating case and its interior are connected through terminal blocks; wherein, the interior of the insulating case includes 1 The sampled resistance voltage divider sampling circuit 2, its output signal is sent to the measurement detection unit 3 to measure the sampling voltage, the measurement detection unit 3 communicates with the MCU unit 4 through the SPI interface, and the measurement value is controlled by the MCU unit 4 Display on the display module 6; power supply and its management unit 10 supply power for the MCU unit 4 and the measurement detection unit 3; the MCU unit 4 is also connected with the infrared communication unit 5, the storage unit 7, the key operation unit 8 and the expansion unit 9; the storage unit is used To record the test data, and record it with an event, the event includes the time of the test, the maximum voltage value, and the duration. the

As shown in Figure 2, the resistance voltage dividing sampling circuit that the present invention adopts is made up of 67 300K resistances (20.1M) connected in series, and its input signal is a high-voltage signal input; the output signal terminal is V3P/V3N, and the resistance dividing sampling circuit Multiple 300K resistors are connected in series, one is to consider the temperature drift effect of the resistors, and the other is to consider the voltage division effect of the resistors. The precision of the resistors selected by this device is below 15ppm, which ensures the measurement accuracy. the

As shown in Figure 3, the metering chip in the metering detection unit of the present invention selects RN8209G; V3P/V3N two pins in the RN8209G are the output end of the input terminal connection resistance voltage divider sampling circuit; RN8209G metering chip communicates with the MCU through the SPI interface For communication, SPI uses 2 control lines and 2 data lines: SCSN, SCLK, SDI and SWI. the

The metering chip RN8209G is a single-phase multi-functional anti-theft special metering chip. RN8209G integrates three channels of second-order Σ-ΔADC. RN8209G can measure active power and active energy, and can simultaneously provide two independent channels of active power and current RMS , RMS voltage, line frequency, zero-crossing interrupt, etc., RN8209G supports full digital gain, phase and offset correction. The active energy pulse is output from the PF pin, and the user-defined energy pulse frequency is output from the QF pin. The power monitoring circuit inside the RN8209G can ensure the reliable operation of the chip when the power is on and off. In RN8209G, a wealth of software calibration methods are provided, which not only saves the trouble of adding an external resistor network, but also has an accuracy of up to 0.5S; V, when the external voltage is 1000V, the sampling voltage is 0.05V, all within the sampling range. the

MCU unit, choose FM3308 as the core control chip. the

The metering chip RN8209G and FM3308 communicate through the SPI interface, and the sampling value is displayed through the display module; the FM3308 chip is equipped with functional modules required for the development of the State Grid smart meter, such as LCD driver, RTC real-time clock, 3 UART ports, and hardware I2C interface etc. the

(1) On the hardware, FM3308 integrates LCD driver and RTC real-time clock into the chip, which improves the integration level;

(2) Software part: the clock timing can ensure the clock accuracy meets the requirements by measuring the temperature and making compensation;

(3) Data storage, which can save historical voltage and current data, set parameters, etc.;

(4) Event recording function: including power-down recording, programming recording, timing recording and event clearing recording, etc.;

(5) Display function: It can display data such as power, time, parameters and measured values. the

As shown in Fig. 4, the input terminal of the power supply and its management module of the present invention is VIN1, and the module uses a linear regulated power supply chip RP130N501D. The chip has the advantages of fast response speed, small output ripple, and low noise generated during work. The output voltage is 5V. In order to increase the output voltage, a reverse diode M7 is added to the ground pin of the chip, and the voltage at the output terminal is 5.7V. the

Fig. 5 is an infrared communication unit. The infrared communication unit includes two parts, as shown in Fig. 5b), one part is an infrared receiving unit; as shown in Fig. 5a), the other part is an infrared sending unit. The invention selects high-efficiency AT205 as the transmitting tube, and the integrated infrared receiver HM238RL-W as the receiving tube. The HM238RL-W receiver packs a photodiode, a preamplifier and a demodulator into one package, and has the functions of receiving infrared signals, built-in signal amplification, 38kHZ filtering, and waveform detection output. the

As shown in Figure 5a), the infrared sending circuit is composed of a triode V25, a resistor R66, a resistor R67 and a sending tube, and the debugged infrared signal is output by pin 18 of the microcontroller. When the high level is sent, it is cut off and there is no signal output; when the low level is sent, the triode is turned on, the infrared sending tube is turned on, and the signal is transmitted. the

As shown in Figure 5b), the highest output low level of the infrared receiver is 0.5V, and the lowest output low level is 0V. The highest output high level is 5V, and the lowest output high level is 4.5V. The working voltage is 4.5-5.5V, and the working current is 0.3-0.6mA. The communication distance is 20 meters (horizontal), the infrared receiver is indicated by V24, R63 is the current limiting resistor, C39 is the decoupling capacitor, and C40 is the filter capacitor with a capacitance of 22pF. the

The test device does not need external power supply during the test, it is powered by the battery, the battery is CR-P2 battery from Wuhan Lixing, the battery voltage is 6V, and the input voltage of the chip is provided by the battery. The test device has been designed in terms of low power consumption. The capacity of the battery is 1500mAh. The battery is turned on during the withstand voltage test, and the battery is turned off after the test. The battery power consumption is about 6mA, and it can perform about 10,000 withstand voltage tests. the

In order to facilitate checking whether the voltage on the withstand voltage tester is accurately added to the single-phase smart energy meter on the meter inspection line, the AC voltage test verification device is made into the same shape and structure as the single-phase smart energy meter. The test voltage range of the AC voltage test and checking device of the present invention is 1000-5000V, the voltage display retains two decimal places, the accuracy reaches 0.1%, the resistor divider series resistance is 20.1MΩ, and the current range of the withstand voltage instrument is 0.05mA-0.25mA during the test; The data of each withstand voltage test is stored in the memory as an event. The event record includes the time of the experiment, the maximum voltage value, and the duration, and can be displayed on a split screen. the

The usage method of the present invention is:

Before leaving the factory, the AC voltage test and verification device is calibrated with a standard source, and the accuracy can reach 0.1%, which is very accurate. When the assembly line automatically verifies the single-phase smart energy meter, do the withstand voltage test project, put the AC voltage verification device and the smart energy meter on the withstand voltage verification platform, and do the 4KV withstand voltage test at the same time, the AC voltage verification device will record the withstand voltage test. The voltage value of the voltage test, the time of occurrence and the duration of the voltage. The error of the withstand voltage tester is within 5% when it leaves the factory. When the single-phase smart energy meter is used as a withstand voltage tester, the voltage value is generally added with 4KV. The difference between the maximum value and the minimum value is about 400V. The test is very inaccurate, so it is relatively For the voltmeter, the AC voltage test verification device is equivalent to a "standard source" to check whether the withstand voltage value added to the single-phase watt-hour meter by the withstand voltage tester is accurate. the

As shown in Figure 6, the output terminal C of the high voltage side of the AC withstand voltage instrument is connected to the strong current terminal of the AC voltage test and verification device; the output terminal D of the low voltage side of the AC withstand voltage instrument is connected to the weak current terminal of the AC voltage test and verification device. the

As shown in Figure 7, the AC voltage test and verification device simulates the structure of a single-phase electric energy meter, in which the high-voltage terminals a, b, c, d, e and f of the AC voltage test and verification device are connected to the high-voltage side of the withstand voltage instrument, and the AC The weak current terminals g, h, i, j, k and l of the voltage test and verification device are connected to the low-voltage side of the withstand voltage instrument. the

After the AC voltage test verification device plus the standard source is calibrated, the output voltage accuracy of the 15 selected verification devices is shown in Table 1 below: the first column indicates the serial number of the extracted verification device, the second column indicates the output voltage of the standard source, and the third column Indicates the output voltage of the verification device, and the fourth column indicates the relative error (%). the

Table 1 extracts the output voltage accuracy of 15 verification devices

Claims (6)

1. examine and determine an AC voltage test check device for robotization single-phase electric energy meter streamline, it is characterized in that, it comprises an insulation crust; Insulation crust is all connected by connection terminal with its inside; Wherein, insulation crust inside comprises, to the electric resistance partial pressure sample circuit of high input voltage signal sampling, its output signal is sent to gauge check unit and measures sampled voltage, described gauge check unit carries out communication by SPI interface and MCU unit, and described variable shows on the display module of MCU unit controls; Power supply and administrative unit thereof are that MCU unit and gauge check unit are powered.

2. a kind of AC voltage test check device examining and determine robotization single-phase electric energy meter streamline as claimed in claim 1, is characterized in that, MCU unit is also that storage unit, key operation unit and expanding element are connected with infrared communication unit.

3. a kind of AC voltage test check device examining and determine robotization single-phase electric energy meter streamline as claimed in claim 1, is characterized in that, described electric resistance partial pressure sample circuit, is made up of multiple 300K resistance of connecting in circuit.

4. a kind of AC voltage test check device examining and determine robotization single-phase electric energy meter streamline as claimed in claim 1, it is characterized in that, power supply and administrative unit thereof adopt linear stabilized power supply chip RP130N501D, add a backward dioded at the grounding pin of chip RP130N501D.

5. a kind of AC voltage test check device examining and determine robotization single-phase electric energy meter streamline as claimed in claim 1, is characterized in that, contour structures size and the single-phase intelligent electric energy meter of described AC voltage test check device are in the same size.

6. a kind of AC voltage test check device examining and determine robotization single-phase electric energy meter streamline as claimed in claim 1, is characterized in that, the test voltage scope of described AC voltage test check device is 1000 ~ 5000V.