Online tester for dynamic parameters of high-speed rail locomotive

Abstract

The utility model discloses a high-speed rail locomotive dynamic parameter on-line tester, and belongs to the technical field of locomotive dynamic parameter detection. The high-speed rail locomotive dynamic parameter online tester solves the problems that an existing high-speed rail locomotive dynamic parameter online tester is large in testing current, long in testing time and low in measuring precision. Collected alternating-current voltage is converted into small voltage through the alternating-current amplitude control circuit, then the voltage is added to the alternating-current and direct-current conversion circuit to be converted into direct-current voltage, the direct-current voltage passes through the isolation amplifier and then is converted into digital signals through the high-speed A / D converter, the single-chip microcomputer receives the digital signals, and the single-chip microcomputer outputs the digital signals. And the data is displayed by the display circuit after being processed by software. And the direct current is converted into direct current voltage through the current-voltage converter and then is measured. The device is suitable for dynamic parameter testing of high-speed rail locomotives.

Description

Technical Field

[0001] The utility model belongs to the technical field of locomotive dynamic parameter detection. Background Art

[0002] At present, the development of high-speed rail technology in my country has ranked first in the world. At the same time, the inspection and testing equipment related to high-speed rail is also constantly innovating with the development of high-speed rail technology. However, the development and utilization of online testers for dynamic parameters of high-speed rail electrical lines needs to be further strengthened, especially in the resistance signal test. Most of the micro-resistance tests use micro-ohm meters, which have a large current constant current source, and the current is generally 100A or 200A. High-frequency switching power supplies and large current transformers are used to achieve the constant current effect of large current. However, these testers have large test currents and long test times, which have an impact on the temperature rise of the measured resistance and reduce the measurement accuracy. Moreover, these measuring instruments are generally large in size and weight, inconvenient to carry on site, and their cost is relatively high. In addition, due to the small contact resistance in the existing measurement process, there are problems of poor measurement accuracy and stability. Summary of the invention

[0003] The present invention aims to solve the problems of large test current, long test time and low measurement accuracy in the existing online tester for dynamic parameters of high-speed railway locomotives. An online tester for dynamic parameters of high-speed railway locomotives is provided.

[0004] The high-speed rail locomotive dynamic parameter online tester of the present invention comprises: an AC amplitude control circuit, an AC to DC conversion circuit, a constant current source circuit, and a resistance test circuit. The circuit comprises: an AC amplitude control circuit, an AC to DC conversion circuit, a constant current source circuit, a resistance test circuit, a DC amplitude control circuit, an isolation amplifier circuit, a high-speed AD conversion circuit, a current-voltage converter, a single-chip microcomputer circuit, an interface circuit, and a display screen;

[0005] The AC amplitude control circuit is used to convert the AC high voltage and low voltage output by the high-speed rail locomotive into AC low voltage signals, and then send the AC low voltage signals to the AC to DC conversion circuit;

[0006] The high voltage is a voltage greater than 1000V, the low voltage is a voltage less than 200mV, and the small voltage is a voltage between 10V and 200mV;

[0007] The AC to DC conversion circuit converts the AC low voltage signal into a DC low voltage signal; and sends the DC low voltage signal to the isolation amplifier circuit;

[0008] The DC amplitude control circuit is used to convert the DC high voltage signal and the low voltage signal output by the high-speed rail locomotive into a DC low voltage signal, and send the DC low voltage signal to the isolation amplifier circuit;

[0009] The current-to-voltage converter is used to convert the DC current signal output by the high-speed rail locomotive into a DC voltage signal, and send the converted DC voltage signal to the isolation amplifier circuit;

[0010] The isolation amplifier circuit isolates and amplifies the received voltage signal and then sends it to the high-speed AD conversion circuit (7);

[0011] The high-speed AD conversion circuit performs analog-to-digital conversion on the received voltage signal and then sends the converted signal to the single-chip microcomputer circuit (10);

[0012] The constant current source circuit is used to generate a stable direct current signal, and the direct current signal is loaded onto the resistor to be tested;

[0013] The resistance testing circuit obtains a voltage signal and a current signal of the resistor to be tested, obtains the resistance value of the resistor to be tested according to the voltage signal and the current signal, and sends the resistance value of the resistor to be tested to the single chip microcomputer circuit;

[0014] The single chip microcomputer circuit sends the received signal to the display screen via the interface circuit;

[0015] The display screen is used to display the received resistance and current signals.

[0016] Furthermore, in the utility model, the isolation amplifier circuit includes an input isolation circuit, a DC amplifier, an output isolation circuit, an analog switch array and a feedback control circuit;

[0017] The input end of the input isolation circuit is the input end of the isolation amplifier circuit, and the input signal is input to the DC amplifier and the feedback control circuit via the input isolation circuit;

[0018] The DC amplifier amplifies the received DC signal according to the received amplification factor information, outputs the amplified signal through the output isolation circuit, and the output isolation circuit transmits the output result signal to the feedback control circuit;

[0019] The feedback control circuit compares the two received signals and sends the difference obtained by the comparison to the analog switch array. The analog switch array obtains the amplification factor information by using the received difference signal and sends the amplification factor information to the DC amplifier.

[0020] Further, in the utility model, the AC to DC conversion circuit includes an input preprocessing circuit, a broadband analog multiplier and an output isolation circuit;

[0021] The input end of the input preprocessing circuit is the input end of the AC to DC conversion circuit;

[0022] The input preprocessing circuit amplifies or reduces the amplitude and frequency of the input AC small voltage signal to obtain an AC voltage signal with an amplitude and frequency in a fixed range; and sends the AC voltage signal to a broadband analog multiplier;

[0023] The broadband analog multiplier performs a square root operation on the received AC voltage signal to obtain a DC effective voltage signal;

[0024] The output isolation circuit is used for isolating and amplifying the DC effective voltage signal and outputting the amplified DC effective voltage signal.

[0025] Furthermore, the utility model also includes a power supply circuit and a power supply battery. The power supply circuit converts the voltage output by the power supply battery into different voltages to power the AC amplitude control circuit, AC to DC conversion circuit, constant current source circuit, resistance test circuit, DC amplitude control circuit, isolation amplifier circuit, high-speed AD conversion circuit, current-voltage converter, single-chip microcomputer circuit, interface circuit and display screen.

[0026] The utility model converts the collected AC voltage into 2V voltage (large voltage attenuates, small voltage amplifies) through the AC amplitude control circuit, and adds it to the AC / DC conversion circuit to convert it into DC voltage. The DC voltage is converted into a digital signal through the isolation amplifier and the high-speed A / D converter. The single-chip microcomputer receives the digital signal and displays it through software processing by the display circuit. The DC voltage measurement is similar to the AC voltage, but it does not need to pass through the AC / DC conversion circuit. The DC current is converted into a DC voltage by the current-voltage converter and then measured. The resistance test is relatively complicated. First, a stable and accurate DC current signal (10mA-0.5A) is generated by the constant current source circuit and added to the measured resistor. The voltage signal of the resistor is processed by the resistance test circuit, and then added to the high-speed A / D converter to convert it into a digital signal, and finally controlled and displayed by the single-chip microcomputer. The test data is stored in the single-chip microcomputer circuit, and transmitted to the computer through the interface circuit for analysis and processing or uploaded to the display screen for display. The power supply circuit converts the battery voltage into various voltages required by the entire system, and can also control the charging of the battery. The key technology is the resistance test technology, and the use of high-stability constant current source technology can ensure the accuracy of the test. High-stability constant current source technology is our own technology developed in the DC standard source project, which can ensure good stability and high accuracy of the output DC current. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a block diagram of the overall principle of the present invention;

[0028] Figure 2 This is the principle block diagram of the isolation amplifier circuit;

[0029] Figure 3This is the block diagram of the AC to DC converter;

[0030] Figure 4 It is a constant current source circuit. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0032] Specific implementation method 1: refer to Figures 1 to 3 Specifically describing this embodiment, the high-speed rail locomotive dynamic parameter online tester described in this embodiment includes: an AC amplitude control circuit 1, an AC to DC conversion circuit 2, a constant current source circuit 3, a resistance test circuit 4, a DC amplitude control circuit 5, an isolation amplifier circuit 6, a high-speed AD conversion circuit 7, a current-voltage converter 9, a single-chip computer circuit 10, an interface circuit 11 and a display screen 12;

[0033] The AC amplitude control circuit 1 is used to convert the AC high voltage and low voltage output by the high-speed rail locomotive into AC low voltage signals, and then send the AC low voltage signals to the AC to DC conversion circuit 2;

[0034] The high voltage is a voltage greater than 1000V, the low voltage is a voltage less than 200mV, and the small voltage is a voltage between 10V and 200mV;

[0035] The AC to DC conversion circuit 2 converts the AC low voltage signal into a DC low voltage signal; and sends the DC low voltage signal to the isolation amplifier circuit 6;

[0036] The DC amplitude control circuit 5 is used to convert the DC high voltage signal and the low voltage signal output by the high-speed rail locomotive into a DC low voltage signal, and send the DC low voltage signal to the isolation amplifier circuit 6;

[0037] The current-to-voltage converter 9 is used to convert the DC current signal output by the high-speed railway locomotive into a DC voltage signal, and send the converted DC voltage signal to the isolation amplifier circuit 6;

[0038] The isolation amplifier circuit 6 isolates and amplifies the received voltage signal and then sends it to the high-speed AD conversion circuit 7;

[0039] The high-speed AD conversion circuit 7 performs analog-to-digital conversion on the received voltage signal and sends it to the single-chip microcomputer circuit 10;

[0040] The constant current source circuit 3 is used to generate a stable direct current signal, and load the direct current signal onto the resistor to be tested;

[0041] The resistance testing circuit 4 obtains the voltage signal and the current signal of the resistor to be measured, obtains the resistance value of the resistor to be measured according to the voltage signal and the current signal, and sends the resistance value of the resistor to be measured to the single chip microcomputer circuit 10;

[0042] The single chip circuit 10 sends the received signal to the display screen 12 via the interface circuit 11;

[0043] The display screen 12 is used to display the received resistance and current signals.

[0044] Furthermore, in the present invention, the isolation amplifier circuit 6 includes an input isolation circuit 61, a DC amplifier 62, an output isolation circuit 63, an analog switch array 64 and a feedback control circuit 65;

[0045] The input end of the input isolation circuit 61 is the input end of the isolation amplifier circuit 6, and the input signal is input to the DC amplifier 62 and the feedback control circuit 65 via the input isolation circuit;

[0046] The DC amplifier 62 amplifies the received DC signal according to the received amplification factor information, and outputs the amplified signal through the output isolation circuit 63, and the output isolation circuit 63 transmits the output result signal to the feedback control circuit 65;

[0047] The feedback control circuit 65 compares the two received signals and sends the difference obtained by the comparison to the analog switch array 64 . The analog switch array 64 obtains the amplification factor information using the received difference signal and sends the amplification factor information to the DC amplifier 62 .

[0048] Furthermore, in the present invention, the AC to DC conversion circuit 2 includes an input preprocessing circuit 201, a broadband analog multiplier (202) and an output isolation circuit 203;

[0049] Input preprocessing circuit 201 The input end of the input preprocessing circuit 201 is the input end of the AC to DC conversion circuit 2;

[0050] The input preprocessing circuit 201 amplifies or reduces the amplitude and frequency of the input AC small voltage signal to obtain an AC voltage signal with an amplitude and frequency in a fixed range; and sends the AC voltage signal to the broadband analog multiplier 202;

[0051] The broadband analog multiplier 202 performs a square root operation on the received AC voltage signal to obtain a DC effective voltage signal;

[0052] The output isolation circuit 203 is used to isolate and amplify the DC effective voltage signal and output the amplified DC effective voltage signal.

[0053] Furthermore, the utility model also includes a power supply circuit and a power supply battery. The power supply circuit converts the voltage output by the power supply battery into different voltages to power the AC amplitude control circuit 1, the AC to DC conversion circuit 2, the constant current source circuit 3, the resistance test circuit 4, the DC amplitude control circuit 5, the isolation amplifier circuit 6, the high-speed AD conversion circuit 7, the current-voltage converter 9, the single-chip computer circuit 10, the interface circuit 11 and the display screen 12.

[0054] In this embodiment, the AC amplitude control circuit is used to convert the output AC high voltage amplitude and low voltage of the high-speed rail locomotive into small voltages, and then send the small voltages to the AC to DC conversion circuit. The AC to DC conversion circuit converts the AC voltage signal into a DC voltage signal through an analog multiplier, and then sends the DC voltage signal to the isolation amplifier circuit for processing. Constant current source circuit: The stable DC reference voltage signal is used to generate a stable and accurate DC current signal through the closed-loop automatic feedback principle, which is used to measure the resistance. Resistance test circuit: The voltage is measured by adding a constant current to the resistor, and the noise interference signal is removed after the voltage signal is processed. The resistance value of the measured resistor is obtained by the known voltage and current. DC amplitude control circuit: It is used to convert the output DC high voltage amplitude and low voltage of the high-speed rail locomotive into a small voltage, and then send the converted small voltage to the isolation amplifier circuit; isolation amplifier circuit: The signals of the AC to DC conversion circuit, the current-voltage converter and the DC amplitude control circuit are isolated and amplified after passing through the analog switch array, and the noise signal is removed at the same time, and sent to the high-speed AD conversion circuit. High-speed AD conversion circuit: Through high-speed data processing, the analog signal is converted into a digital signal and sent to the single-chip microcomputer circuit for data processing; current-voltage converter: It is used to convert the output DC current of the high-speed rail locomotive into a DC voltage, and the converted DC voltage is sent to the isolation amplifier circuit. Single-chip microcomputer circuit: Process the data and send it to the display screen for display. Interface circuit: The main function is to receive the command from the input key and send it to the microcontroller circuit control circuit for processing. At the same time, the test data can be downloaded through the interface circuit. Display screen: It is mainly used to display the measurement results and function menus.

[0055] The utility model uses automatic feedback direct current constant current source technology and calculation true effective value technology to develop a portable high-speed rail locomotive dynamic parameter online tester with high stability, high accuracy and high resolution.

[0056] (1) Develop a high-stability DC current source. The stable DC voltage reference UREF is amplified to the required power by a DC voltage amplifier (amplification factor B) and a current power amplifier (amplification factor W) and connected to the output terminal. The output DC signal is converted to a voltage signal by a current-to-voltage converter (conversion coefficient R) and then the difference is calculated with the DC current reference signal. The calculated error is amplified (amplification factor K) and added to the DC current reference. After feedback adjustment, the output signal is stabilized at the set value. The control principle of the constant current source circuit is as follows: Figure 4 shown.

[0057] When the circuit enters steady state, the output voltage I o for

[0058] I o =(UREF-KRI o )BW

[0059] It can be introduced:

[0060] I o =UREF / KR

[0061] UREF is the DC reference voltage, K is the error amplifier gain, R is the current to voltage conversion factor, B is the voltage amplifier gain, and W is the current power amplifier gain.

[0062] It can be seen that the output DC current is proportional to the reference voltage and inversely proportional to the error amplification K and the current-voltage conversion coefficient R. As long as the three links are controlled well, the stability and accuracy of the DC output current can be guaranteed.

[0063] (2) Develop a true effective value AC to DC converter for AC voltage measurement. Multi-purpose digital meters with less than 4.5 digits often use the average value measurement method. The measurement circuit is simple, and the accuracy will decrease when the waveform distortion is large. There are many methods for effective value measurement, and the commonly used ones are high-speed sampling and calculation. The high-speed sampling method is based on the definition of effective value, and the AC voltage is sampled at high speed, and then calculated by computer. This method requires good repeatability of the measured signal and has high requirements for A / D converters and computers. Another commonly used method is the calculation method. The calculation method can be completed by an operational amplifier, and there is also an integrated effective value converter, which is relatively simple to use. A high-accuracy AC-DC converter is the basis for ensuring the measurement of AC voltage. From the AC-DC converters that are widely used at present, there are two types: calculation method and thermoelectric method. The true effective value calculation method AC-DC converter has the characteristics of fast speed and high accuracy. This system uses a true effective value calculation method AC-DC converter to ensure the accuracy of AC measurement.

[0064] The utility model uses analog multipliers to develop operational true effective value technology, so that the AC voltage measurement accuracy reaches 0.02% rdg ± 5dgt. At the same time, the automatic feedback DC constant current source technology and dynamic zero tracking measurement amplifier are adopted to make the small resistance measurement range wide and the accuracy reach 0.1% rdg ± 5dgt.

[0065] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. High-speed rail locomotive dynamic parameter online tester, characterized in that: include: AC amplitude control circuit (1), AC to DC conversion circuit (2), constant current source circuit (3), resistance test circuit (4), DC amplitude control circuit (5), isolation amplifier circuit (6), high-speed AD conversion circuit (7), current-voltage converter (9), single-chip computer circuit (10), interface circuit (11) and display screen (12); The AC amplitude control circuit (1) is used to convert the AC high voltage and low voltage output by the high-speed rail locomotive into AC low voltage signals, and then send the AC low voltage signals to the AC to DC conversion circuit (2); The high voltage is a voltage greater than 1000V, the low voltage is a voltage less than 200mV, and the small voltage is a voltage between 10V and 200mV; The AC to DC conversion circuit (2) converts the AC low voltage signal into a DC low voltage signal; and sends the DC low voltage signal to the isolation amplifier circuit (6); The DC amplitude control circuit (5) is used to convert the DC high voltage signal and the low voltage signal output by the high-speed rail locomotive into a DC low voltage signal, and send the DC low voltage signal to the isolation amplifier circuit (6); The current-to-voltage converter (9) is used to convert the DC current signal output by the high-speed rail locomotive into a DC voltage signal, and send the converted DC voltage signal to the isolation amplifier circuit (6); The isolation amplifier circuit (6) isolates and amplifies the received voltage signal and then sends it to the high-speed AD conversion circuit (7); The high-speed AD conversion circuit (7) performs analog-to-digital conversion on the received voltage signal and then sends the converted signal to the single-chip microcomputer circuit (10); The constant current source circuit (3) is used to generate a stable direct current signal, and the direct current signal is loaded onto the resistor to be tested; The resistance testing circuit (4) obtains a voltage signal and a current signal of the resistor to be tested, obtains a resistance value of the resistor to be tested according to the voltage signal and the current signal, and sends the resistance value of the resistor to be tested to the single chip computer circuit (10); The single chip microcomputer circuit (10) sends the received signal to the display screen (12) via the interface circuit (11); The display screen (12) is used to display the received resistance and current signals.

2. The high-speed rail locomotive dynamic parameter online tester according to claim 1 is characterized in that: The isolation amplifier circuit (6) comprises an input isolation circuit (61), a DC amplifier (62), an output isolation circuit (63), an analog switch array (64) and a feedback control circuit (65); The input end of the input isolation circuit (61) is the input end of the isolation amplifier circuit (6), and the input signal is input to the DC amplifier (62) and the feedback control circuit (65) via the input isolation circuit (61); The DC amplifier (62) amplifies the received DC signal according to the received amplification factor information, outputs the amplified signal via the output isolation circuit (63), and the output isolation circuit (63) transmits the output result signal to the feedback control circuit (65); The feedback control circuit (65) compares the two received signals and sends the difference obtained by the comparison to the analog switch array (64). The analog switch array (64) obtains amplification factor information using the received difference signal and sends the amplification factor information to the DC amplifier (62).

3. The high-speed railway locomotive dynamic parameter online tester according to claim 1 or 2, characterized in that: The AC to DC conversion circuit (2) comprises an input preprocessing circuit (201), a broadband analog multiplier (202) and an output isolation circuit (63); The input end of the input preprocessing circuit (201) is the input end of the AC to DC conversion circuit (2); The input preprocessing circuit (201) amplifies or reduces the amplitude and frequency of the input AC low voltage signal to obtain an AC voltage signal with an amplitude and frequency within a fixed range; and sends the AC voltage signal to a broadband analog multiplier (202); The broadband analog multiplier (202) performs a square root operation on the received AC voltage signal to obtain a DC effective voltage signal; The output isolation circuit (63) is used for isolating and amplifying the DC effective voltage signal and outputting the amplified DC effective voltage signal.

4. The high-speed railway locomotive dynamic parameter online tester according to claim 3 is characterized in that: The invention also comprises a power supply circuit and a power supply battery. The power supply circuit converts the voltage output by the power supply battery into a different voltage to supply power to an AC amplitude control circuit (1), an AC to DC conversion circuit (2), a constant current source circuit (3), a resistance test circuit (4), a DC amplitude control circuit (5), an isolation amplifier circuit (6), a high-speed AD conversion circuit (7), a current-voltage converter (9), a single-chip computer circuit (10), an interface circuit (11) and a display screen (12).

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