CN101008674A - Device for testing axial displacement of hydroelectric generating set and working method therefor - Google Patents

Abstract

The invention relates to a detection device for the axial displacement of a hydroelectric generating set and its working method. The device includes a central control unit, a transmission drive circuit, a reception drive circuit, a detection result output device, a first transducer and a second transducer There is a reflector at a distance H2 from the second transducer; the central control unit calculates the sound velocity v in the current environment through the time information T2 captured by the second transducer, and then combines the time information captured by the first transducer T1 is used to calculate the current axial displacement of the hydro-generator set and control the detection result output device to output the axial displacement information of the hydro-generator set. The central control unit of the present invention performs sound velocity correction through the second transducer and its reflecting plate to detect the sound velocity in the current environment, eliminating the influence of factors such as ambient temperature, humidity, dust amount, and wind speed on the measured displacement. Using methods such as temperature or humidity compensation, it has the characteristics of simple structure, high calculation accuracy and high speed.

Description

Axial Displacement Detecting Device and Working Method of Hydrogenerator Set

technical field

The invention relates to a detection device and a working method for the axial displacement of a hydroelectric generating set of a hydropower station.

Background technique

With the gradual development of my country's hydropower resources, large and medium-sized hydraulic turbines are continuously put into production, which makes the proportion of large hydraulic turbines in the entire power grid more and more large. The average annual power generation time is prolonged and the maintenance time is shortened. Once an accident stops, the economic loss caused is extremely high. serious. Therefore, it is very necessary to ensure the normal and safe operation of large-scale hydraulic turbines, monitor their status, find fault symptoms in time, and carry out fault diagnosis research on hydraulic turbines. In the research of fault diagnosis, the study of turbine vibration is an important index directly related to the normal operation of the hydroelectric generating set. The above-mentioned related content was disclosed in "Hydraulic and Hydropower Technology" 1995 (3) "Hydraulic Turbine Generating Unit Operation Status Monitoring" and "Journal of Harbin Institute of Technology" 1998 (additional) "Dynamic Stability Research of Hydroelectric Generating Set" .

The vibration information of the hydroelectric generating set will be reflected in its axial displacement information to a large extent. Therefore, the detection of the axial displacement information of the hydro-generator set plays a very important role in ensuring the safety, reliability and stability of the hydro-generator set. "The Large Axis Displacement of Hydrogenerator Sets" in "Journal of Sun Yat-Sen University (Natural Science Edition)" 2003 (addition 2), "The Analysis and Analysis of the Large Axis Displacement of Hydrogenerator Sets" in "Guangdong Water Conservancy and Hydropower" 2002 (1) Treatment" and "Journal of Vibration Engineering" 2000 (additional) "Calculation of Shafting Vibration of Hydrogenerator" discloses relevant content.

The traditional axial displacement detection methods of hydro-generators are as follows:

(1) Mechanical hydraulic axial displacement monitoring and protection device. The device has simple structure, reliable action and easy adjustment. But it does not have an indicator, and cannot monitor the change of the shaft displacement during operation. The contact directly contacts the rotor flange, which will be worn during operation, which will affect the accuracy.

(2) Hydraulic axial displacement protection device. This device has no mechanical wear problem, and the protection operation is accurate and reliable, but it cannot accurately indicate the axial displacement value, and the displacement change can only be roughly seen from the change of the oil pressure of the monitoring pressure gauge, and the relationship between displacement and oil pressure is not shown. Linear, the adjustment is not very convenient. When the pressure oil pressure changes greatly, the spring on the wrong throttle must be replaced, which increases the complexity of the adjustment system.

(3) Inductive axial displacement measurement protection device. It works on the principle of electromagnetic induction. The axial displacement transmitter converts the rotor mechanical displacement variable into the induced voltage variable. On the one hand, the electrical instrument indicates the change of the axial displacement of the rotor; achieve a protective effect. The device has no mechanical wear and is not affected by changes in oil pressure, but the detection function is relatively simple.

(4) An intelligent axial displacement monitor based on a single-chip microcomputer. With the development of modern electronic monitoring technology and microcomputer technology, intelligent monitoring instruments based on single-chip microcomputers have become the direction. However, most of its primary sampling signals are electrical signals, which are easily disturbed by the harsh on-site environment, and due to the limitations of the single-chip microcomputer itself, such as weaknesses such as long instruction execution cycles, it is difficult to collect fast and accurate changes.

Some existing large-scale hydropower stations use high-precision sensors for online monitoring, but this method is costly, the sensors used depend on imports, and the maintainability of the system is not high, making it difficult to popularize and apply.

Chinese patent document CN2602385 discloses an ultrasonic range finder, which is composed of a host computer and a target. Connect the ultrasonic transmitting circuit or the infrared transmitting circuit, connect the host amplifying circuit after the ultrasonic transmitting circuit, the host ultrasonic transmitting/receiving sensor transmits and receives the measuring signal, and the measuring signal emitted by the infrared transmitting circuit passes through the infrared receiving circuit, the target amplifying circuit, Oscillating circuit, target ultrasonic transmitting circuit, target ultrasonic transmitting sensor transmitting, target ultrasonic receiving sensor receiving, pre-amplifier circuit amplified and then connected to the host amplifier circuit, the output of the host amplifier circuit is integrated by the integration circuit and then input to the microprocessor for calculation The measured value is displayed by the liquid crystal display and stored in the memory.

Chinese patent document CN2657016 discloses a kind of ultrasonic ranging device with sensitivity automatic gain function, and this device includes microprocessor; An ultrasonic transmitting circuit; An ultrasonic receiving circuit; An echo signal amplifying circuit; An echo signal detecting circuit , a display circuit and a digital potentiometer, the digital potentiometer is connected with the microprocessor and the operational amplifier of the echo signal amplifying circuit, the microprocessor controls the digital potentiometer, so that the digital potentiometer automatically changes its output resistance to Adjust the magnification of the echo signal so that a relatively balanced echo signal can be obtained during the entire distance measurement process, and effectively shield the generation of false display signals such as geodesy without affecting the short-distance distance measurement.

Chinese patent document CN1099870 discloses a method and device for ultrasonic distance measurement, which is characterized in that the transmitted wave is a pulse signal wave with time sequence characteristics composed of a plurality of square envelope pulse waves, and the repetition period pulse width of each square envelope pulse wave is preset. Set, the microcomputer only gates the signal with timing characteristics.

Chinese patent document CN2645091 discloses an ultrasonic rangefinder with the same body type for transmitting and receiving. It includes a transducer, a transmitting circuit, a receiving circuit, and a single-chip controller. The transducer is connected with the transmitting circuit and the receiving circuit. It is connected with the single-chip controller, and the single-chip controller is connected with the upper computer; the single-chip controller controls the transmitting circuit, so that the ultrasonic transmitting circuit drives the transducer to transmit ultrasonic narrow pulse train signals at regular intervals, and at the same time, the transducer receives the reflected wave, and the receiving circuit will After the reflected wave is amplified and processed, it is sent to the single-chip controller. The single-chip controller captures the time interval corresponding to the peak value of the transmitted wave and the reflected wave, and then transmits the time signal to the host computer with the RS-485 bus standard.

The above-mentioned ultrasonic distance measuring devices in the prior art all use a microprocessor to control the emission and reception of ultrasonic waves, and use the time interval between the emission and reception of ultrasonic waves to calculate the measured distance. However, since the speed of sound in the air is affected by various factors, such as ambient temperature, humidity, dust volume, wind speed, etc., and the above technical solutions have not taken corresponding compensation measures, the error of the detection result is relatively large, generally above 10mm , which cannot meet the accuracy requirements of the axial displacement detection of the hydraulic turbine generator set, and the error requirement is less than 0.1mm.

Chinese patent document CN2356355 discloses an ultrasonic distance measuring device, which adopts gain amplification, peak detection and transit time detection. The gain amplification circuit is used to adjust the amplitude of the echo signal generated by the pre-amplification; the peak detection circuit is used to eliminate the interference signal, and the echo peak value is detected to enter the single-chip A/D conversion channel; the transit time detection circuit is used to judge whether the echo If it is an echo, stop the timer, request the single-chip microcomputer to interrupt, read in the timing value, and the single-chip microcomputer completes the distance calculation. At the same time, a temperature detection circuit is used as temperature compensation to correct the sound velocity.

Japanese patent document JP11044759 discloses an ultrasonic rangefinder capable of accurately compensating the influence of air temperature. The ultrasonic range finder has a signal transmitting device, a signal receiving device, a pulse signal generating device and a distance calculating device. The frequency of the pulse signal generated by the pulse signal generating device changes with the change of temperature. The signal transmitting device sends an ultrasonic wave to the object under test until the signal receiving device receives the reflected ultrasonic wave, and the distance calculating device counts the number of pulse signals and calculates the distance to the object under test according to the number of pulse signals.

Japanese patent document JP2000088959 also discloses an ultrasonic range finder similar to Japanese patent document JP11044759, and its distinguishing feature is that the frequency signal used is adjustable.

The above-mentioned ultrasonic distance measuring device in the prior art also utilizes a microprocessor to control the emission and reception of ultrasonic waves, and uses the time interval between the emission and reception of ultrasonic waves to calculate the measured distance. Accuracy requirements for the detection of the axial displacement of the generator set. On the one hand, the speed of sound is affected by many factors, such as ambient temperature, humidity, dust volume, wind speed, etc., and it is not enough to take temperature compensation measures alone. On the other hand, the detection device in the above technical solution only uses a single-chip microcomputer as the central control unit, and its calculation rate and accuracy are not high enough. The reason is mainly affected by the instruction execution time of the microprocessor used and the interrupt response time of the microprocessor. For example, the microprocessor adopts the 51 series single-chip microcomputer commonly used at present. If the crystal oscillator is 12MHz, one machine cycle still needs It takes 1us to enter the interrupt, and it needs to perform jump, stack and other process instructions. The working speed is low, and there is still an error of 6-10us. Calculated according to the propagation speed of sound waves in the air of 340m/s, it will lead to the measurement distance. 2.04-3.4mm error. However, the alarm limit of the axial displacement detection of the hydro-generator set is ±5mm, and the axial displacement rate and frequency of the hydro-generator set due to vibration are relatively high. The speed requirements and accuracy requirements of the displacement detection. In addition, even if the operating frequency and accuracy of the single-chip microcomputer can be improved by increasing the operating frequency of the crystal oscillator used in the single-chip microcomputer, the problem brought about is that the working stability and reliability of the single-chip microcomputer will be greatly reduced, and it is not suitable for water wheels with high stability requirements. Actual requirements for axial displacement detection of generator sets.

Chinese patent document CN2591642 discloses a kind of ultrasonic ranging device, and it is made up of ultrasonic generator, pulse modulator, amplifier, transmitting transducer, receiving transducer, filter amplifier, wave detector, clock pulse generator, display, buzzer It is composed of circuit and components of controller and controller, and its controller is realized with a CPLD chip. The device can measure the distance between the transducer and the target object, and the test result is displayed through the digital tube. When the measured distance is less than the preset threshold value, the buzzer will alarm. The disadvantage of this device is that, on the one hand, the device does not consider the influence of factors such as ambient temperature, humidity, dust amount, wind speed, etc. that the speed of sound in the air may be subjected to; on the other hand, the device only uses CPLD to collect ultrasonic propagation time And through the digital tube display to display the distance of the target object, the detection results cannot be sent to the monitoring terminal, and the alarm limit cannot be manually set, the alarm history can be checked, and the measurement data can be checked in real time. At the same time, in this device, the output frequency of the ultrasonic generator is 40KHz, the output frequency of the pulse modulator is 2Hz, the duty cycle is 0.05%, the amplification factor of the filter amplifier is 60dB, and the output frequency of the clock pulse generator is 170.0KHz. The result is the measured distance in mm. The maximum measurement distance of the ultrasonic distance measuring device realized by this scheme is 8.6m, the error is less than 2.0mm, and the minimum alarm threshold is 1Cm. Obviously, this device cannot meet the accuracy requirements of the axial displacement detection of the hydro-generator set, and can only be used in occasions where the detection accuracy is low, such as motor vehicle reversing collision avoidance, blind pathfinding, and robot positioning.

Contents of the invention

The object of the present invention is to provide a detection device and working method for the axial displacement of the hydroelectric generating set to solve the above-mentioned existing problems.

In order to achieve the above object, the present invention provides the following technical solution: design a detection device for the axial displacement of the hydroelectric generating set, including a central control unit, a transmission drive circuit connected to the ultrasonic output control terminal of the central control unit, and a central control unit. The receiving drive circuit connected to the echo signal receiving end of the control unit, the detection result output device and the first transducer connected to the detection result output end of the central control unit; the output end of the transmitting drive circuit and the input of the first transducer The input end of the receiving drive circuit is connected with the output end of the first transducer; it is characterized in that: it also has a second transducer, the output end of the transmitting drive circuit is connected with the input end of the second transducer, and the second transducer is connected to the input end of the second transducer. The output end of the second transducer is connected to the input end of the receiving drive circuit, and a reflector is provided at a distance H2 from the second transducer; The shaft end of the hydroelectric generating set is a transducer that transmits ultrasonic narrow pulse train signals and receives echoes; the second transducer is a transducer for transmitting ultrasonic narrow pulse train signals to the reflector and receiving echoes; the central control The unit is used to control the timing transmission and echo reception of the ultrasonic narrow burst signal and capture the time information T1 and T2, at the same time, calculate the sound velocity v in the current environment according to the time information T2, and then calculate the current distance H11 between the first transducer and the measured surface according to the time information T1, so as to calculate the axial displacement of the hydro-generator set and control the detection The result output device is a central control unit that outputs the axial displacement information of the hydroelectric generating set.

The initial distance H1 refers to the distance between the first transducer and the measured surface when the hydroelectric generating set stops working.

The working method of the detection device for the axial displacement of the hydroelectric generating set of the present invention comprises:

The central control unit controls the first transducer and the second transducer to regularly transmit ultrasonic narrow pulse train signals through the transmitting drive circuit; the central control unit receives echoes through the receiving drive circuit to capture the first transducer and the second transducer respectively. The time information T1 and T2 used by the transducer during the transmission and reception of the respective ultrasonic narrow burst signals, and then calculate the sound velocity v in the current environment according to the time information T2 and the distance H2 from the second transducer to the reflector, and then Combining the time information T1 to calculate the current distance H11 between the first transducer and the measured surface to calculate the axial displacement ΔH of the hydro-generator set, that is, the distance between the initial distance H1 and H11 between the first transducer and the measured surface difference; the central control unit outputs the axial displacement information of the hydroelectric generating set through the detection result output device.

Compared with the prior art, the above technical solution of the present invention has the following advantages: (1) in the detection device for the axial displacement of the hydraulic turbine generator set of the present invention, the central control unit performs sound velocity correction through the second transducer and its reflecting plate, To detect the speed of sound in the current environment, thereby eliminating the influence of environmental temperature, humidity, dust volume, wind speed and other factors on the measurement of the current displacement ΔH; compared with the traditional method of temperature or humidity compensation, it has a simple structure and significant effect. features. (2) In the working method of the detection device for the axial displacement of the hydroelectric generating set of the present invention, the counting pulse signal with a frequency of 20 to 200 times the frequency of the ultrasonic narrow pulse train signal is used for pulse counting, so as to capture the first transduced energy respectively. The time information T1 and T2 used by the transducer and the second transducer during the transmission and reception of their respective ultrasonic narrow burst signals, calculate the sound velocity v in the current environment according to T2 and H2, and then combine the time information T1 to calculate the current first The distance between the transducer and the measured surface is H11 to calculate the axial displacement ΔH of the hydro-generator set, with high calculation accuracy and speed.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below in conjunction with the specific embodiments according to the accompanying drawings, wherein

Fig. 1 is the implementation schematic diagram of the detection device of the axial displacement of the hydroelectric generating set of the present invention;

Fig. 2 is the circuit block diagram of the detection device of the hydraulic generator set axial displacement of the present invention;

Fig. 3 is a circuit block diagram of another detection device for the axial displacement of the hydroelectric generating set of the present invention;

Fig. 4 is the block diagram of the hardware logic function circuit realized by ASIC among Fig. 3;

Fig. 5 is a schematic circuit diagram of the central control unit in Fig. 3;

Fig. 6 is a circuit schematic diagram of the receiving drive circuit in Fig. 3;

FIG. 7 is a circuit schematic diagram of the emission driving circuit in FIG. 3;

Fig. 8 is the circuit schematic diagram of the keyboard control circuit in Fig. 3;

Fig. 9 is a schematic circuit diagram of the data display module in Fig. 3;

Fig. 10 is the schematic circuit diagram of the RS-485 remote communication module in Fig. 3;

Fig. 11 is the schematic circuit diagram of the RS-232 communication module in Fig. 3;

Fig. 12 is a schematic diagram of the power supply circuit of the present invention;

FIG. 13 is a program flow diagram of the ASIC in FIG. 3 .

Detailed ways

(Example 1)

See Fig. 1-2, the detection device of the axial displacement of the hydraulic turbine generator set in this embodiment includes a central control unit 1, a transmitting drive circuit 2 connected to the ultrasonic output control terminal of the central control unit 1, and a central control unit 1 The receiving drive circuit 3 connected to the receiving end of the echo signal, the detection result output device connected to the detection result output end of the central control unit 1, the first transducer 21 and the second transducer 22. The output end of the transmitting drive circuit 2 is connected to the input end of the first transducer 21, and the input end of the receiving drive circuit 3 is connected to the output end of the first transducer 21; the output end of the transmitting drive circuit 2 is connected to the second transducer The input end of the second transducer 22 is connected, the output end of the second transducer 22 is connected with the input end of the receiving drive circuit 3 , and a reflector 24 is provided at a distance H2 from the second transducer 22 .

The first transducer 21 is a transducer for transmitting ultrasonic narrow pulse train signals to the measured surface 23 at an initial distance of H1, that is, the shaft end of the hydroelectric generator set, and receiving echoes.

The second transducer 22 is a transducer for transmitting ultrasonic narrow pulse train signals to the reflector and receiving echoes.

The central control unit 1 is used to control the timing transmission and echo reception of ultrasonic narrow burst signals and respectively capture the first transducer 21 and the second transducer 22 used during the transmission and reception of respective ultrasonic narrow burst signals. Time information T1 and T2 of the time information, at the same time calculate the sound velocity v in the current environment according to the time information T2, and then combine the time information T1 to calculate the current distance H11 between the first transducer 21 and the measured surface, so as to calculate the axis of the hydro-generator unit The central control unit that outputs the axial displacement information of the hydroelectric generating set to the displacement amount and controls the detection result output device.

The initial distance H1 refers to the distance between the first transducer 21 and the measured surface 23 when the hydroelectric generating set stops working.

The first transducer 21 and the second transducer 22 are arranged on the top plate 25 and the initial distance H1 from the first transducer 21 to the measured surface 23 is greater than the distance H2 from the second transducer 22 to the reflector 24 . And the H1 is 3-8 meters, and the H2 is 1-2 meters. In this embodiment, H1 is 6 meters, and H2 is 1.5 meters.

The working method of the detection device for the axial displacement of the hydroelectric generating set includes: the central control unit 1 controls the first transducer 21 and the second transducer 22 to regularly transmit ultrasonic narrow pulse train signals through the transmission drive circuit 2; the central control unit 1. Receiving the echo through the receiving drive circuit 3 to respectively capture the time information T1 and T2 used by the first transducer 21 and the second transducer 22 during the transmission and reception of the respective ultrasonic narrow burst signals, and then according to the time information T2 and the distance H2 from the second transducer 22 to the reflector 24 to calculate the sound velocity v in the current environment, and then combine the time information T1 to calculate the current distance H11 between the first transducer 21 and the measured surface 23 to calculate The axial displacement of the hydro-generator set ΔH, that is, the difference between the initial distance H1 from the first transducer 21 to the measured surface 23 and the H11; the central control unit 1 outputs the axial displacement of the hydro-generator set through the detection result output device to the displacement information.

The central control unit 1 in this embodiment is a digital signal processor DSP. In other embodiments, the central control unit 1 may be a control device such as a single-chip microcomputer or an ARM embedded processor.

The present invention can also have following modification on the basis of embodiment 1:

(Example 2)

See Fig. 3, described central control unit 1 comprises single-chip microcomputer 11 and the application-specific integrated circuit ASIC 12 that is bidirectionally electrically connected with single-chip microcomputer 11.

The ultrasonic output control end of the central control unit 1 is the ultrasonic output control end of the application-specific integrated circuit ASIC 12, the echo signal receiving end of the central control unit 1 is the echo signal receiving end of the application-specific integrated circuit ASIC12, and the central control unit 1 The detection result output terminal is the detection result output terminal of the single-chip microcomputer 11 .

The application-specific integrated circuit ASIC 12 is used to control the transmission and reception of the ultrasonic narrow burst signal to capture the first transducer 21 and the second transducer 22 respectively during the transmission and reception of the ultrasonic narrow burst signal. time information T1 and T2, and send the time information T1 and T2 to the application-specific integrated circuit ASIC of the single-chip microcomputer 11.

The single-chip microcomputer 11 receives the time information T1 and T2 from the application-specific integrated circuit ASIC 12, and calculates the sound velocity v in the current environment according to the time information T2, and then combines the time information T1 to calculate the current first transducer 21 and the measured frequency. The distance H11 of the surface is used to calculate the axial displacement of the hydro-generator set and control the detection result output device to output the single-chip microcomputer of the axial displacement information of the hydro-generator set.

See Fig. 4, the hardware logic function circuit that application-specific integrated circuit ASIC 12 realizes comprises the main control module that is used to receive the control signal from single-chip microcomputer 11 and the echo signal from receiving drive circuit 3, the second frequency output module, the third frequency output Module, a frequency division module that divides the signal of the first frequency _f1 input from the outside and simultaneously generates a signal of the second frequency _f2 and a signal of the third frequency _f3 , a 16-bit counter and a decoding module.

The control signal output terminal of the single-chip microcomputer 11 is connected with the control signal input terminal of the main control module, and the control output terminal of the main control module is connected with the control input terminals of the second frequency output module, the third frequency output module, 16-bit counter and the decoding module. The second frequency output terminal and the third frequency output terminal of the frequency module are respectively connected with the frequency signal input terminals of the second frequency output module and the third frequency output module, and the output terminal of the second frequency output module is connected with the counting frequency input of the 16-bit counter connected, the counting output of the 16-bit counter is connected to the counting input of the decoding module, the counting output of the decoding module is connected to the time information input of the single-chip microcomputer 11, and the output of the third frequency output module is also the ultrasonic wave of the application-specific integrated circuit ASIC 12. The output control terminal is connected with the control input terminal of the emission drive circuit 2 .

The application-specific integrated circuit (ASIC) adopted in the present invention can be complex programmable logic device CPLD or field programmable gate array FPGA, and its hardware logic function can be realized by user's on-site programming, has the advantages of high integration, fast working speed, convenient programming and low price. Advantages such as low cost. Especially CPLD, its internal logic structure is simple, the connection is relatively fixed, the delay is small and predictable, which is more conducive to the operation of the device at high frequency, and the system speed can easily reach and exceed 300MHz. The timing characteristics of CPLD are generally measured in nanoseconds. ns or MHz description, CPLD input to output delay can be as short as 3.0ns. Therefore, the application-specific integrated circuit ASIC is used to control the transmission and reception echoes of ultrasonic narrow burst signals to capture the time information used during the transmission and reception of ultrasonic narrow burst signals, with fast speed, small error and stable and reliable operation. In the present embodiment, the single-chip microcomputer 11 is an 8051 single-chip microcomputer, and the application-specific integrated circuit ASIC 12 adopts a complex programmable logic device CPLD, and the specific model is Mars-95108 of Xilinx Company.

The counting frequency adopted by the complex programmable logic device CPLD in this embodiment, that is, the second frequency f ₂ is 1 MHz, the third frequency f ₃ is 40 kHz, and the first frequency f ₁ is 32 MHz. The first frequency _f1 is input by an external crystal oscillator. The 1MHz pulse signal is used to count the pulses during the transmission and reception of the ultrasonic narrow pulse train signal, so as to obtain accurate echo time, so that the captured time information T1 and T2 in this embodiment are accurate to 1us level, and make The maximum theoretical measurement error is 0.17 mm, which overcomes the limitation of speed and precision of only using single-chip microcomputer in the prior art. In the present invention, if the counting frequency, that is, the second frequency f ₂ is increased, the measurement accuracy and measurement response rate can be further improved without affecting the working stability of the CPLD. Simultaneously in the present invention, single-chip microcomputer 11 calculates the speed of sound in the current environment according to the time information T2, calculates the distance H11 between the current first transducer 21 and the measured surface according to the time information T1, and finally outputs the water by the detection result output device. The axial displacement of the turbine generator set and the operation of the single-chip microcomputer have almost negligible influence on the accuracy of the detection results, so the grade and use cost of the single-chip microcomputer can be reduced.

Referring to Fig. 6-7, the first transducer 21 and the second transducer 22 are connected to the transmitting drive circuit 2 and the receiving drive circuit 3 through the interface J10. The Vi(S) terminal of the transmitting drive circuit 2 receives the ultrasonic output control signal from the ultrasonic output control terminal Vi(S) of the CPLD, and after being amplified by U11A, it is sent to the Vo(S) terminal of the interface J10 to drive the first transducer 21 and the second transducer 22 output ultrasonic narrow pulse train signals. When H2 is 1.5 meters and H1 is 6 meters, the second transducer 22 and the first transducer 21 successively receive the echoes, and successively input the received signals from the receiving drive circuit 3Vi end, and pass through the amplifying circuit U11B, U12A and U12B are amplified, and then output to the V_flec end of the echo signal receiving end of CPLD U2 through the comparator U13A and the optocoupler U14 of model H11L1, so as to realize the echo signal reception. The optocoupler U14 realizes the isolation of the analog circuit and the digital circuit, and enhances the anti-interference ability.

See Fig. 13, the working method of the detecting device for the axial displacement of the hydroelectric generating set of the present embodiment includes: the single-chip microcomputer 11 regularly sends out control instructions to the application-specific integrated circuit ASIC 12, so that the application-specific integrated circuit ASIC 12 controls the first A transducer 21 and a second transducer 22 regularly emit ultrasonic narrow pulse train signals, and receive echoes through the receiving drive circuit 3, the first transducer 21 and the second transducer 22; During the transmitting and echo receiving period of the ultrasonic narrow pulse train signal of the transducer 22, the application-specific integrated circuit ASIC 12 uses the pulse signal of the second frequency _f2 to perform pulse counting until there is the first echo signal, and the pulse count value m2 is obtained , which is the time information T2; during the transmission and echo reception of the ultrasonic narrow pulse train signal of the first transducer 21, the application specific integrated circuit ASIC 12 uses the pulse signal of the second frequency _f2 to perform pulse counting until There is the echo signal for the first time, and the pulse count value m1 is obtained, which is the time information T1; the application-specific integrated circuit ASIC12 sends the time information T1 and T2 to the single-chip microcomputer 11; the single-chip microcomputer 11 receives the time from the application-specific integrated circuit ASIC 12 information T1 and T2, and calculate the sound velocity v in the current environment according to the time information T2, and then combine the time information T1 to calculate the current distance H11 between the first transducer 21 and the measured surface 23, so as to calculate the axial The displacement ΔH is the difference between the initial distance H1 and H11 between the first transducer 21 and the measured surface 23; the central control unit 1 outputs the axial displacement information of the hydroelectric generator set through the detection result output device. Wherein, the second frequency _f2 is 20 to 200 times of the ultrasonic narrow pulse train signal frequency _f3 , so that the counting pulses have higher counting accuracy and reduce errors; in the present embodiment, the second frequency _f2 is 1MHz, The third frequency f ₃ is 40 kHz, and the first frequency f ₁ is 32 MHz.

(Example 3)

See Fig. 5, on the basis of above-described embodiment, single-chip microcomputer 11 is 8 single-chip microcomputers namely 8051 single-chip microcomputers U1, and single-chip microcomputers 11 are bidirectionally electrically connected with application-specific integrated circuit ASIC 12 namely CPLD U2 through eight in-phase three-state bus transceivers U13. Eight in-phase three-state bus transceivers are used, so that the data communication terminals AD0-AD7 of the single-chip microcomputer U1 can be multiplexed by the data communication terminals of the test result output device, and only one 8-bit single-chip microcomputer can be used to reduce costs. The ultrasonic output control terminal of CPLD U2 is the Vi(S) terminal of U2 in the figure, the echo signal receiving terminal of CPLD U2 is the V_flec terminal of U2 in the figure, and the detection result output terminal of the single-chip microcomputer 11 is the data communication terminal AD0 of U1 in the figure -AD7 terminal, A13 of U1 is the addressing terminal, and RD is the control terminal. The first frequency _f1 of 32 MHz is input to U2 from the crystal oscillator Y1 through the CLK terminal.

The detection result output device includes a data display module 4 (see FIG. 9 ) connected to the single-chip microcomputer 11 for displaying the axial displacement information of the hydro-generator set, and an RS module for realizing remote monitoring of the axial displacement information of the hydro-generator set by the remote monitoring center. -485 remote communication module 5 (see Figure 10), RS-232 communication module 7 (see Figure 11) for monitoring the axial displacement information of the hydro-generator set via the host computer, and used for when the axial displacement information of the hydro-generator set is measured When the displacement is greater than the set alarm limit, an alarm device such as a buzzer will be turned on to alarm.

8, there is also a keyboard control circuit 6 connected to the single-chip microcomputer 11, which is used to manually set the alarm limit, query the alarm history, check the measurement data in real time and set the working status of the single-chip microcomputer 11 through the data display module 4. Keyboard control circuit 6 is connected with data communication terminal AD0-AD7, addressing terminal A11 and control terminal RD of single-chip microcomputer U1 through eight in-phase three-state bus transceivers U3, so that the data communication terminals AD0-AD7 of single-chip microcomputer U1 realize multiplexing, to reduce cost. Wherein, the INT0 end is an interrupt signal output end connected with the INT0 end of the microcontroller.

As shown in Figure 9, when the data display module 4 is working and displaying, firstly, the RD pin, WR pin and A15 pin of the single-chip microcomputer U1 send control signals to make the LCD effective through the processing of the gate circuit U5, and then the single-chip microcomputer sends commands to the LCD through the data ports AD0-AD7 and data to make the LCD display the corresponding data. A8 and A9 are addressing terminals.

In Figure 10, the R0 terminal and DI terminal of the remote communication module MAX485 are connected to the RxD terminal and TxD terminal of the single-chip microcomputer respectively, and its 2nd pin and 3rd pin are connected to the P16 terminal of the single-chip microcomputer, and the interface J9 is used as the RS-485 remote communication interface. Used for remote communication.

The power supply circuit in Fig. 12 is used to supply power to each circuit.

On the basis of embodiment 2, the working method of the detection device of the axial displacement of the hydroelectric generator set also includes: a keyboard control circuit 6 connected with the single chip microcomputer 11, for manually setting the alarm limit through the data display module 4, Query the alarm history, check the measurement data in real time and set the working status of the single-chip microcomputer 11; the remote monitoring center connected with the single-chip microcomputer 11 is used for remote monitoring of the axial displacement information of the hydroelectric generator set through the RS-485 remote communication module 5; The RS-232 communication module 7 is connected with the single-chip microcomputer 11 to monitor the axial displacement information of the hydro-generator set; Call the police.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And these obvious changes or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims (10)

1, the pick-up unit of a kind of hydraulic generator unit axial displacement comprises central control unit (1), the emission driving circuit (2) that links to each other with the ultrasound wave output control terminal of central control unit (1), the reception driving circuit (3) that links to each other with the echoed signal receiving end of central authorities' control single (1), testing result output unit, first transducer (21) that links to each other with the testing result output terminal of central control unit (1); The output terminal of emission driving circuit (2) links to each other with the input end of first transducer (21), and the input end that receives driving circuit (3) links to each other with the output terminal of first transducer (21);

It is characterized in that: also have second transducer (22), the output terminal of emission driving circuit (2) links to each other with the input end of second transducer (22), the output terminal of second transducer (22) links to each other with the input end that receives driving circuit (3), is provided with reflecting plate (24) with second transducer (22) at a distance of the H2 place;

First transducer (21) be used for to its initial separation be that the tested surface (23) at H1 place is the axle head emission ultrasound wave burst pulse string signal of hydraulic generator unit and the transducer that receives echo;

Second transducer (22) is to be used for to reflecting plate (24) emission ultrasound wave burst pulse string signal and to receive the transducer of echo;

Central control unit (1) is to be used to control the timing emission of ultrasound wave burst pulse string signal and echo to receive and catch respectively first transducer (21) and second transducer (22) used temporal information T1 and T2 during the transmitting and receiving of separately ultrasound wave burst pulse string signal, simultaneously calculate velocity of sound v in the current environment according to temporal information T2, binding time information T1 calculates the distance H 11 of current first transducer (21) and tested surface then, to calculate the central control unit of hydraulic generator unit axial displacement and control detection output unit output as a result hydraulic generator unit axial displacement information.

2, the pick-up unit of hydraulic generator unit according to claim 1 axial displacement, it is characterized in that: first transducer (21) and second transducer (22) are arranged on (25) on the top board, and first transducer (21) to the initial separation H1 of tested surface (23) greater than the spacing H2 of second transducer (22) to reflecting plate (24).

3, the pick-up unit of hydraulic generator unit according to claim 2 axial displacement is characterized in that: described central control unit (1) comprise single-chip microcomputer (11) and with the two-way application-specific integrated circuit ASIC that is electrically connected of single-chip microcomputer (11) (12);

The ultrasound wave output control terminal of central control unit (1) is the ultrasound wave output control terminal of application-specific integrated circuit ASIC (12), the echoed signal receiving end of central authorities' control single (1) is the echoed signal receiving end of application-specific integrated circuit ASIC (12), and the testing result output terminal of central control unit (1) is the testing result output terminal of single-chip microcomputer (11);

Application-specific integrated circuit ASIC (12) be used to control ultrasound wave burst pulse string signal transmit and receive echo catching first transducer (21) and second transducer (22) used temporal information T1 and T2 during the transmitting and receiving of separately ultrasound wave burst pulse string signal respectively, and described temporal information T1 and T2 are delivered to the application-specific integrated circuit ASIC of single-chip microcomputer (11);

Single-chip microcomputer (11) is described temporal information T1 and the T2 that receives from application-specific integrated circuit ASIC (12), and calculate velocity of sound v in the current environment according to temporal information T2, back binding time information T1 calculates the distance H 11 of current first transducer (21) and tested surface, to calculate the single-chip microcomputer of hydraulic generator unit axial displacement and control detection output unit output as a result hydraulic generator unit axial displacement information.

4, the pick-up unit of hydraulic generator unit according to claim 3 axial displacement is characterized in that: the hardware logic functional circuit that application-specific integrated circuit ASIC (12) is realized comprises and is used for receiving from the control signal of single-chip microcomputer (11) with from the main control module of the echoed signal that receives driving circuit (3), second frequency output module, the 3rd frequency output module, to the first frequency f of outside input ₁Signal carry out frequency division and generate second frequency f simultaneously ₂Signal and the 3rd frequency f ₃Frequency division module, 16 digit counters and the decoder module of signal;

The control signal output ends of single-chip microcomputer (11) connects the signal input end of main control module, the control output end of main control module and second frequency output module, the 3rd frequency output module, the control input end of 16 digit counters and decoder module links to each other, the second frequency output terminal of frequency division module links to each other with the frequency signal input end of second frequency output module with the 3rd frequency output module respectively with the 3rd frequency output terminal, the output terminal of second frequency output module links to each other with the count frequency input end of 16 digit counters, the terminal count output of 16 digit counters connects the counting input end of decoder module, the terminal count output of decoder module connects the temporal information input end of single-chip microcomputer (11), and the output terminal of the 3rd frequency output module also is that the ultrasound wave output control terminal of application-specific integrated circuit ASIC (12) links to each other with the control input end of emission driving circuit (2).

5, according to the pick-up unit of the described hydraulic generator unit of one of claim 3-4 axial displacement, it is characterized in that: single-chip microcomputer (11) is 8 single-chip microcomputers, and single-chip microcomputer (11) is through eight homophase tristate bus line transceivers and two-way electrical connection of application-specific integrated circuit ASIC (12).

6, the pick-up unit of hydraulic generator unit according to claim 5 axial displacement is characterized in that: the testing result output unit comprises the data disaply moudle (4) that is used to show hydraulic generator unit axial displacement information that links to each other with single-chip microcomputer, be used to realize the RS-485 remote communication module (5) of remote monitoring center remote monitoring hydraulic generator unit axial displacement information, be used for RS-232 communication module (7) through ipc monitor hydraulic generator unit axial displacement information, be used for the warning device (8) of when recording hydraulic generator unit axial displacement, reporting to the police greater than the alarm limit set.

7, the pick-up unit of hydraulic generator unit according to claim 6 axial displacement, it is characterized in that: also be provided with the keyboard control circuit (6) that links to each other with single-chip microcomputer (11), be used for alarm limit, inquiry alarm history manually being set, consulting measurement data and the duty of single-chip microcomputer (11) is set in real time by data disaply moudle (4).

8, a kind of method of work of the pick-up unit according to the axial displacement of above-mentioned hydraulic generator unit comprises:

Central control unit (1) is regularly launched ultrasound wave burst pulse string signal by emission driving circuit (2) control first transducer (21) and second transducer (22);

Central control unit (1) receives echo by receiving driving circuit (3), to catch first transducer (21) and second transducer (22) used temporal information T1 and T2 during the transmitting and receiving of separately ultrasound wave burst pulse string signal respectively, the back is calculated velocity of sound v in the current environment according to temporal information T2 and second transducer (22) to the spacing H2 of reflecting plate (24), binding time information T1 calculates the spacing H11 of current first transducer (21) and tested surface (23) then, to calculate hydraulic generator unit axial displacement Δ H, also be that first transducer (21) is to the initial separation H1 of tested surface (23) and the difference of H11;

Central control unit (1) is by testing result output unit output hydraulic generator unit axial displacement information.

9, the method for work of the pick-up unit of hydraulic generator unit according to claim 8 axial displacement is characterized in that: central control unit (1) comprise single-chip microcomputer (11) and with the two-way application-specific integrated circuit ASIC that is electrically connected of single-chip microcomputer (11) (12);

Single-chip microcomputer (11) regularly sends steering order to application-specific integrated circuit ASIC (12), make application-specific integrated circuit ASIC (12) regularly launch ultrasound wave burst pulse string signal, and receive echo by receiving driving circuit (3), first transducer (21) and second transducer (22) by emission driving circuit (2) control first transducer (21) and second transducer (22);

In the emission and echo reception period of the ultrasound wave burst pulse string signal of described second transducer (22), application-specific integrated circuit ASIC (12) utilizes second frequency f ₂Pulse signal carry out step-by-step counting, and counted number of pulses m2, be temporal information T2;

In the emission and echo reception period of the ultrasound wave burst pulse string signal of described first transducer (21), application-specific integrated circuit ASIC (12) utilizes second frequency f ₂Pulse signal carry out step-by-step counting, and counted number of pulses m1, be temporal information T1; Second frequency f ₂Be ultrasound wave burst pulse string signal frequency f ₃20 to 200 times;

Application-specific integrated circuit ASIC (12) is delivered to single-chip microcomputer (11) with described temporal information T1 and T2;

Single-chip microcomputer (11) receives described temporal information T1 and the T2 from application-specific integrated circuit ASIC (12), and calculate velocity of sound v in the current environment according to temporal information T2, back binding time information T1 calculates the spacing H11 of current first transducer (21) and tested surface (23), to calculate hydraulic generator unit axial displacement Δ H, promptly first transducer (21) is to the initial separation H1 of tested surface (23) and the difference of H11;

Central control unit (1) is by testing result output unit output hydraulic generator unit axial displacement information.

10, the method for work of the pick-up unit of hydraulic generator unit according to claim 9 axial displacement, it is characterized in that: the keyboard control circuit (6) that links to each other with single-chip microcomputer (11) is used for alarm limit, inquiry alarm history manually being set, consulting measurement data and the duty of single-chip microcomputer (11) is set in real time by data disaply moudle (4);

The remote monitoring center that links to each other with single-chip microcomputer (11) is used for the axial displacement information of remote monitoring hydraulic generator unit by RS-485 remote communication module (5);

Host computer links to each other with single-chip microcomputer (11) by RS-232 communication module (7), with monitoring hydraulic generator unit axial displacement information;

When recording hydraulic generator unit axial displacement greater than the alarm limit set, single-chip microcomputer (11) is reported to the police by coupled warning device 8.

Images