Equiphase acquisition system for hydroelectric generating set vibration signals
By adopting an equal phase acquisition system in the vibration signal acquisition system of the hydroelectric unit, combined with DC coupling and disconnection detection technology, the problems of low signal acquisition accuracy and difficulty in fault positioning of existing systems are solved, and high-precision signal acquisition and effective fault positioning are achieved.
Patent Information
- Application Number
- CN202411766952.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-04-11
AI Technical Summary
The existing hydroelectric unit vibration signal acquisition system has low signal acquisition accuracy and cannot effectively locate faults.
The equal phase acquisition system is adopted, including a power supply unit, an interface unit, a storage unit, a display unit, a main control unit, a collection unit, an isolation unit, a disconnect detection and DC coupling unit. The signal phase accuracy is improved through DC coupling, and fault positioning is achieved through the disconnection detection function.
It improves the accuracy of the vibration signal acquisition of the hydroelectric unit, can accurately locate faults, and enhances the system's maintenance and fault analysis capabilities.
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Figure CN119803653A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of signal acquisition, and in particular to an equal-phase acquisition system for vibration signals of a hydropower unit. Background Art
[0002] The traditional key phase signal acquisition method usually sets a groove on the measured shaft, which is called the key phase mark. When the groove is rotated to the probe position, it is equivalent to a sudden change in the distance between the probe and the measured surface. The sensor will generate a pulse. Every time the shaft rotates one circle, a pulse signal will be generated. The time of generation indicates the position of the shaft in each rotation cycle. By counting the pulses, the speed of the rotating shaft can be measured. By comparing the pulses with the vibration signal of the rotating shaft, the phase angle of the vibration can be determined, which is used for dynamic balance analysis of the shaft and fault analysis and diagnosis of the equipment.
[0003] The signal output by the key phase sensor is a pulse / square wave, which contains a low-level potential, a high-level potential and a common-mode voltage. The common-mode voltage is related to the sensor installation position. The distance between the sensor and the key phase position is related to the common-mode voltage. Existing solutions generally use AC coupling to collect key phase signals. The accuracy of signal acquisition is poor, and when the entire system fails, the system fault cannot be located.
[0004] Based on the above problems, there is an urgent need for a hydropower unit vibration signal acquisition system that can improve signal acquisition accuracy and realize fault location. Summary of the invention
[0005] In view of the low accuracy of vibration signal acquisition of hydropower units and the inability to locate system faults, the present application provides an equal-phase acquisition system for vibration signals of hydropower units to solve the above problems.
[0006] To achieve the above object, the present invention is implemented through the following technical solutions: The embodiment of the present application discloses an equal phase acquisition system for vibration signals of a hydropower unit, comprising: Power supply unit: The power supply unit provides power to the entire board, including isolated power supply, digital power supply and analog power supply; Interface unit: The interface unit is a communication interface with the host computer or other boards. The board is controlled by the host computer to obtain the collected signals and can be linked with other boards to complete operations or command actions; Storage unit: The storage unit stores various information of the board, including the ID, version number and operation log of the board, stores the waveform of the signal generated by the collected signal value, and stores the waveform information of the signal to be output; Display unit: The display unit can display the running status of the board, including the overall running status of the board and the running status of each channel; Main control unit: The main control unit contains a specific execution program, which controls all other units according to the execution program; Acquisition unit: The acquisition unit is the main component for collecting key phase signals. It processes the key phase signals accordingly and converts them into digital signals through the digital-to-analog conversion circuit in the acquisition unit.
[0007] Isolation unit: The isolation unit is for digital interface isolation, isolating the high-frequency noise of the main control unit, the acquisition unit and the output unit; Wire break detection and DC coupling unit: DC coupling is used to obtain the distance information between the sensor position and the key phase position, and the wire break detection function can realize fault location.
[0008] The above technical scheme is adopted: the above scheme is that the equal phase acquisition system of the vibration signal of the water supply generator set is equipped with corresponding disconnection detection and DC coupling units. The use of DC coupling can improve the phase accuracy of the key phase signal, and the distance information of the sensor position and the key phase position can be obtained. Moreover, during DC coupling, the accuracy is not affected within a certain frequency range, and the disconnection detection function can realize fault location when a fault occurs.
[0009] Preferably, the line break detection and DC coupling unit includes: a first operational amplifier U1, the reverse input terminal and the output terminal of the first operational amplifier U1 are electrically connected to a resistor R3 to form a voltage follower, the non-inverting input terminal of the first operational amplifier U1 is electrically connected to a current limiting resistor R2, the non-inverting input terminal of the first operational amplifier U1 is also connected to a power supply VCC through R1, and the output terminal of the first operational amplifier U1 is also electrically connected to a resistor R4 and a capacitor C1, and the capacitor C1 is grounded.
[0010] The above technical solution is adopted: the above solution discloses a circuit of a disconnection detection and DC coupling unit, which can determine whether a collection system is disconnected by means of circuit signal detection.
[0011] Further preferably, the acquisition unit includes a key phase acquisition circuit, the key phase acquisition circuit includes a second operational amplifier, the in-phase input terminal of the second operational amplifier is electrically connected to a resistor R18 and a resistor R8 that are electrically connected to each other, the input end of a capacitor C13 is also connected between the connecting line between the resistor R18 and the resistor R8, the output end of the capacitor C13 is electrically connected to the output end of the second operational amplifier, the in-phase input terminal of the second operational amplifier is also electrically connected to a capacitor C18, the capacitor C18 is grounded, and the input end of the acquisition unit is electrically connected to the output end of the line break detection and DC coupling unit.
[0012] By adopting the above technical solution, the key phase acquisition circuit provided above can realize the acquisition of key phase signals.
[0013] Further preferably, the acquisition unit also includes a key phase output circuit, which includes: a central control module U11, the power output end of the central control module U11 is grounded through capacitors C46 and C49, the power input end of the central control module U11 is connected to a 24V voltage input, and the central control module U11 sets a limited current value through a resistor, and the current limit value is limited to a range of ≤50mA.
[0014] Further preferably, the isolation unit comprises: a power isolation unit and a signal isolation unit, the power isolation unit adopts two power isolation modules, and the signal isolation unit uses an ADIADuM series isolation IC to isolate the digital signal of the ADC.
[0015] Further preferably, the main control unit includes: an FPGA module and peripheral circuits, the FPGA module contains a specific program, and can collect and output signals according to the program settings, the FPGA also includes a communication interface, and the communication interface can connect other boards and a host computer, and the PFGA can be configured through the host computer to distribute the signals.
[0016] Further preferably, the storage unit comprises: an EEPROM chip, a power supply access terminal of the EEPROM chip is electrically connected to a power supply via a magnetic bead FB8, and a power supply access terminal of the EEPROM chip is grounded via a capacitor C95.
[0017] Further preferably, the digital power supply includes a 3.3V power rail and a 5V power rail, the 3.3V power rail is used for IO power supply and isolation IC, and the 5V power rail is used to power the FPGA module; The analog power supply includes an isolated power supply and other power supplies. The isolated power supply includes two Jinshengyang power modules. The input voltage of the Jinshengyang power modules is 24V, and the output voltage is ±12V and ±24V; the other power supplies are converted and output from the two Jinshengyang power modules.
[0018] Further preferably, it also includes a signal matrix unit, which includes: a key phase board module and an external device module, the key phase board module includes multiple key phase input terminals and multiple key phase output terminals, the external device module includes multiple input terminals, when the external device module needs a zero point of the key phase signal seat time, the signal is introduced into the external device module through a connecting line, and the signal matrix unit is configured with a signal matrix function.
[0019] Further preferably, it also includes: an ADC module, the ADC module is configured in serial mode, a passive RC filter is configured at the input end of the ADC module to filter out noise outside the high-frequency band, and the four channels of the ADC module are used for collecting input board cards. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 This is a circuit connection block diagram of the equal phase acquisition system of the vibration signal of the hydropower unit in this application; Figure 2 For this application, the line break detection and DC coupling unit circuit; Figure 3 This is the circuit diagram of the key phase acquisition circuit of this application; Figure 4 This is the circuit diagram of the key phase output circuit of this application; Figure 5 The circuit diagram of the isolation unit for this application; Figure 6 This is the circuit diagram of the main control unit of this application; Figure 7 The circuit diagram of the storage unit for this application; Figure 8 A schematic diagram of the power supply unit circuit for this application; Fig. 9 This is a schematic block diagram of the signal matrix unit of this application; Fig.10 This is the circuit diagram of the ADC module for this application.
[0022] In the figure: 1. Power supply unit; 2. Interface unit; 3. Storage unit; 4. Display unit; 5. Main control unit; 6. Acquisition unit; 7. Isolation unit; 8. Disconnection detection and DC coupling unit; 9. Output unit. DETAILED DESCRIPTION
[0023] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.
[0024] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.
[0025] See also Figure 1-Figure 10 For example, in the prior art solution, AC coupling is used for acquisition. AC coupling filters out the common mode voltage. Although the key phase information can be obtained, the installation position information of the sensor is unclear. AC coupling uses the charging and discharging of capacitors to achieve signal transmission. The charging and discharging of capacitors is related to the frequency, which causes errors in the signal and causes phase shift. AC coupling generally cannot detect line breaks, which is not conducive to maintenance and fault location during subsequent use. When the same key phase signal needs to be analyzed, the key phase signal needs to be connected to different boards through wiring, and if different key phase signals need to be switched, the wiring method needs to be adjusted accordingly.
[0026] Based on the above problems, the embodiment of the present application discloses an equal phase acquisition system for vibration signals of a hydropower unit, comprising: Power supply unit 1: Power supply unit 1 provides power for the entire board, including isolated power supply, digital power supply, and analog power supply. The digital power supply supplies power for the digital circuit part (main control unit 5, storage unit, interface unit 2, display unit 4, etc.), and the analog power supply supplies power for the analog circuit part (acquisition unit 6, output unit 9, etc.). The isolated power supply and the isolated power supply separate the digital circuit and the analog circuit to prevent the high-frequency noise of the digital circuit from affecting the analog circuit.
[0027] Interface unit 2: Interface unit 2 is a communication interface with the host computer or other boards. The board is controlled by the host computer to obtain the collected signals and can be linked with other boards to complete operations or command actions; Storage unit 3: Storage unit 3 stores various information of the board, including the ID, version number and operation log of the board, stores the waveform of the signal generated by the collected signal value, and stores the waveform information of the signal to be output; Display unit 4: Display unit 4 can display the running status of the board, including the overall running status of the board and the running status of each channel; Main control unit 5: The main control unit 5 contains a specific execution program, and controls all other units according to the execution program; Acquisition unit 6: Acquisition unit 6 is the main component for collecting key phase signals, performs corresponding processing on the key phase signals, and converts them into digital signals through the digital-to-analog conversion circuit in the acquisition unit 6.
[0028] Isolation unit 7: The isolation unit 7 is for digital interface isolation, isolating the high-frequency noise of the main control unit 5, the acquisition unit 6 and the output unit 9; Wire break detection and DC coupling unit 8: By adopting DC coupling, the distance information between the sensor position and the key phase position can be obtained, and the wire break detection function can realize fault location.
[0029] It is worth mentioning that the above scheme of the equal phase acquisition system of the vibration signal of the water supply generator set is equipped with a corresponding disconnection detection and DC coupling unit 8. The use of DC coupling can improve the phase accuracy of the key phase signal, and the distance information of the sensor position and the key phase position can be obtained. In addition, the DC coupling does not affect the accuracy within a certain frequency range. The present invention can realize input disconnection detection. During the process of detecting the signal, if the signal input signal is suddenly interrupted, the board can automatically identify it and prompt an alarm. Possible reasons for the interruption of the signal input include: the sensor is damaged or the connecting harness is damaged or loose due to vibration and other reasons.
[0030] like Figure 2 As shown in, the disconnection detection and DC coupling unit 8 includes: a first operational amplifier U1, the reverse input terminal and the output terminal of the first operational amplifier U1 are electrically connected to a resistor R3 to form a voltage follower, the non-inverting input terminal of the first operational amplifier U1 is electrically connected to a current limiting resistor R2, the non-inverting input terminal of the first operational amplifier U1 is also connected to the power supply VCC through R1, and the output terminal of the first operational amplifier U1 is also electrically connected to a resistor R4 and a capacitor C1, and the capacitor C1 is grounded. The above scheme discloses a circuit of a disconnection detection and DC coupling unit 8, which can realize the judgment of whether the acquisition system is disconnected by circuit signal detection.
[0031] The voltage acquisition input range is -20V to +24V. The first-stage input op amp uses a 10M resistor to pull up to +24.5V. The external signal is an output signal, the internal resistance of the source end is very small, and the driving ability is large. The 10M resistor pull-up has little effect on the input signal. Therefore, when there is an external input, the level of the op amp's in-phase end is determined by the drive signal. When there is no external input, the level of the op amp's in-phase end is pulled up to +24.5V by the 10M resistor.
[0032] It is worth mentioning that the input structure mentioned above is a high-impedance input of the op amp, which is implemented by direct DC coupling. U1 is an operational amplifier, which forms a voltage follower with R3. R2 is the current-limiting resistor at the non-inverting input of the op amp U1. R1 is a large-value resistor, one end of which is connected to the non-inverting input of the op amp and the other end is connected to the power supply VCC. When there are two input signals at one input end, the signal level is determined by the driving capability of the input signal. When there is no external input signal, the non-inverting end of U1 has only one input, which is VCC input to the non-inverting end of U1 through R1. Since the input impedance of the non-inverting end of U1 is very large, much larger than the value of R1, for the non-inverting end of U1, the input signal at this time is VCC. When there is an external signal input, since R1 is a resistor with a large resistance value, the driving capability is much smaller than the driving capability of the external input signal. For the non-inverting end of U1, the input signal at this time is the external input signal.
[0033] The disconnection detection is based on the above principle. The input signal is a known range value. The maximum actual input range of the system we design here exceeds the input signal range. At the same time, the input end is pulled up to a value exceeding the input signal range through a large resistor R1. Here, if the actual input range is designed to exceed the signal input range too much, the effective resolution of the measurement system will be wasted. Therefore, it is generally not exceeded. The signal input range is ±24V, and we design the input range to be ±24.5V.
[0034] It is necessary to ensure that the measurement system has sufficient effective resolution, and at the same time, the detected broken wire fault signal value must fall outside the input signal range. Therefore, when we collect a value that is not within the input range of the signal, we consider the line to be broken.
[0035] DC coupling means coupling the signal in without using capacitors. It is generally used in situations where the common mode level of the signal is relatively high.
[0036] As shown in the figure above, during AC coupling, R2 is adjusted to a capacitor, and the charging and discharging of the capacitor is used to couple the signal. However, the RC network composed of the coupling capacitor and the input resistor, C in the RC network is easily affected by temperature and humidity. At the same time, the transfer function of the RC network itself is related to the frequency. When C changes, its output will change with C. In the working environment of this system, the temperature and humidity may change at any time. This reduces the acquisition accuracy during AC coupling.
[0037] When DC coupling is used, the input link is to some extent resistive devices, and its transfer function is independent of frequency. This greatly improves the phase accuracy of the acquisition. The difficulty of DC coupling is that the common-mode voltage level of general signals is very high, and the system needs to have a very wide input range to cover it. We can achieve a maximum peak-to-peak input of 50V, which can cover the input range of the key phase signal. DC coupling can also be used to obtain the value of the common-mode voltage, which is related to the distance between the sensor and the key phase position. The distance between the sensor and the key phase position can be analyzed.
[0038] The acquisition unit 6 includes a key phase acquisition circuit, which includes a second operational amplifier, the in-phase input end of the second operational amplifier is electrically connected to a resistor R18 and a resistor R8 electrically connected to each other, the connection line between the resistor R18 and the resistor R8 is also connected to the input end of a capacitor C13, the output end of the capacitor C13 is electrically connected to the output end of the second operational amplifier, the in-phase input end of the second operational amplifier is also electrically connected to a capacitor C18, the capacitor C18 is grounded, and the input end of the acquisition unit 6 is electrically connected to the output end of the disconnection detection and DC coupling unit 8. The key phase acquisition circuit provided in the above can realize the acquisition of key phase signals. It is worth mentioning that after the input signal passes through the resistor, it will be given to the first-stage operational amplifier, the operational amplifier is ADA4522, the maximum power supply is Vs=55V, the self-zero operational amplifier, and the rail-to-rail output. The input range is V- to V+-1.5V, and under the power supply of +26V to -24V, it can support -20V to +24V input. The output of the first-stage op amp is designed as a voltage follower, which is divided by a high-precision, low-temperature drift resistor and input to the second-stage op amp, with a voltage division ratio of 100 / 250. The third stage is a filter circuit. The acquisition unit 6 also includes a key phase output circuit, which includes: the output signal is generated by the FPGA and given to the driver after isolation by ADuM141. The maximum of ADuM141 is 150Mbps, which meets our frequency requirements here. The driver selects TIOS1023, which supports PushPull output, high-side output, and low-side output. The current limit value can be set by resistors. The current limit is currently limited to 50mA. Built-in overcurrent diagnosis, after overcurrent occurs, a signal will be fed back to the FPGA through Fault.
[0039] The central control module U11 has a power output terminal connected to ground via capacitors C46 and C49, a power input terminal connected to a 24V voltage input, and a current limiting value set via a resistor, wherein the current limiting value is limited to a range of ≤50mA.
[0040] The isolation unit 7 includes: a power isolation unit 7 and a signal isolation unit 7. The power isolation unit 7 uses two power isolation modules, with an operating temperature range of -40°C to 85°C, a maximum output power of 6W, and an actual power usage of less than 2W. The primary and secondary power supply meet 3KV withstand voltage.
[0041] The signal isolation unit 7 uses an ADIADuM series isolation IC to isolate the digital signal of the ADC; and uses ADuM141 isolation with a maximum withstand voltage of 3KV.
[0042] The main control unit 5 includes: an FPGA module and a peripheral circuit. The FPGA module contains a specific program, which can collect and output signals according to the program settings. The FPGA also includes a communication interface, which can connect other boards and a host computer. The host computer can configure PFGA to distribute signals. The main control unit 5 consists of FPGA and peripheral circuits (storage, temperature, etc.). The FPGA contains a specific program, which can collect and output signals according to the program settings. There is a specific communication interface that can be connected to other boards or a host computer. The host computer can configure PFGA to distribute signals (signal matrix), and the collected key phase signal can be recorded in the storage unit or transmitted to other boards or a host computer through the communication interface. PFGA has rich computing resources and can perform signal processing on the signal, such as Fourier transforming the signal and extracting the amplitude of the characteristic frequency point. The main control unit 5 also includes a temperature sensor that can measure the working temperature. When the temperature is too high, it can be reported through the communication interface to drive the external heat dissipation device to dissipate heat.
[0043] The storage unit 3 includes an EEPROM chip, a power supply access terminal of the EEPROM chip is electrically connected to a power supply via a magnetic bead FB8, and the power supply access terminal of the EEPROM chip is grounded via a capacitor C95.
[0044] The digital power supply includes a 3.3V power rail and a 5V power rail. The 3.3V power rail is used for IO power supply and isolation IC, and the 5V power rail is used to power the FPGA module. The digital power supply is implemented using TPS5430 DC-DC. TPS5430 has a maximum current of 3A, which fully meets the power supply requirements of the existing system.
[0045] The analog power supply includes an isolated power supply and other power supplies. The isolated power supply includes two Jinshengyang power modules. The input voltage of the Jinshengyang power modules is 24V, and the output voltage is ±12V and ±24V; the other power supplies are converted and output from the two Jinshengyang power modules.
[0046] The digital power supply here is implemented using a DCDC power supply. Digital power supply has a large power demand, and high DCDC efficiency can reduce heat generation. The analog power supply is implemented using an LDO. Analog power supply has a small power demand but high requirements for power supply ripple noise. LDO can provide a large PSRR (power supply rejection ratio), which can greatly suppress ripple noise.
[0047] It also includes a signal matrix unit, which includes: a key phase board module and an external device module, the key phase board module includes multiple key phase input terminals and multiple key phase output terminals, the external device module includes multiple input terminals, when the external device module needs a zero point of the key phase signal seat time, the signal is introduced into the external device module through a connecting line, and the signal matrix unit is configured with a signal matrix function.
[0048] When an external device needs a key phase signal as the "zero point" of time, the signal is generally introduced to other devices through a connecting line. When there are multiple key phase signals, if the external device needs to switch different key phase signal sources, it is necessary to adjust the wiring. This system has a built-in "signal matrix" that can be switched through software without changing the wiring.
[0049] Let's take an example to illustrate. When the key phase output signal of the key phase board is connected to the external device, the default internal mapping key phase input 1 is mapped to key phase output 1. At this time, the signal on the input 1 of the external device is the key phase input 1 signal. If the external device needs to apply key phase input 3 to input 1 of the external device, if there is no matrix function, the wiring needs to be adjusted. However, our board can map the key phase input 3 signal to key phase output 1 through internal mapping, so it can be achieved without adjusting the wiring.
[0050] It also includes: an ADC module, which is configured in serial mode. A passive RC filter is configured at the input end of the ADC module to filter out high-frequency out-of-band noise. The four channels of the ADC module are used for input board acquisition. The ADC selects AD7606, 16 bits, bipolar, and supports input to ±10V under 5V power supply. It can withstand a maximum of ±16.5V without damage. A passive RC filter with a cutoff frequency of 48MHz is passed through the input ADC to filter out high-frequency out-of-band noise. The ADC has 8 channels, and 4 channels are used for input acquisition of the board. Configure the ADC as a serial mode external reference. The OS is configured to 000, no oversampling, and the maximum sampling rate is 200Ksps. Input signal resolution: 0.76mV.
[0051] Unless otherwise specified, the device components involved in the above embodiments are all conventional device components, and the connection methods and control methods involved are all conventional connection methods and control methods unless otherwise specified.
[0052] The present invention has been described in detail above in conjunction with the embodiments. However, those skilled in the art will appreciate that, without departing from the spirit of the present invention, the specific parameters in the above embodiments may be changed to form a plurality of specific embodiments, which are all within the common variation range of the present invention and will not be described in detail herein.
Claims
1. An equal phase acquisition system for vibration signals of a hydropower unit, characterized in that: include, Power supply unit: The power supply unit provides power to the entire board, including isolated power supply, digital power supply and analog power supply; Interface unit: The interface unit is a communication interface with the host computer or other boards. The board is controlled by the host computer to obtain the collected signals and can be linked with other boards to complete operations or command actions; Storage unit: The storage unit stores various information of the board, including the ID, version number and operation log of the board, stores the waveform of the signal generated by the collected signal value, and stores the waveform information of the signal to be output; Display unit: The display unit can display the running status of the board, including the overall running status of the board and the running status of each channel; Main control unit: The main control unit contains a specific execution program, which controls all other units according to the execution program; Acquisition unit: The acquisition unit is the main component for collecting key phase signals, performs corresponding processing on the key phase signals, and converts them into digital signals through the digital-to-analog conversion circuit in the acquisition unit; Isolation unit: The isolation unit is for digital interface isolation, isolating the high-frequency noise of the main control unit, the acquisition unit and the output unit; Wire break detection and DC coupling unit: DC coupling is used to obtain the distance information between the sensor position and the key phase position, and the wire break detection function can realize fault location.
2. The equal phase acquisition system for vibration signals of a hydropower unit according to claim 1 is characterized in that: The disconnection detection and DC coupling unit includes: a first operational amplifier U1, the inverting input terminal and the output terminal of the first operational amplifier U1 are electrically connected to a resistor R3 to form a voltage follower, the non-inverting input terminal of the first operational amplifier U1 is electrically connected to a current limiting resistor R2, the non-inverting input terminal of the first operational amplifier U1 is also connected to a power supply VCC through R1, and the output terminal of the first operational amplifier U1 is also electrically connected to a resistor R4 and a capacitor C1, and the capacitor C1 is grounded.
3. The equal phase acquisition system for vibration signals of a hydropower unit according to claim 2 is characterized in that: The acquisition unit includes a key phase acquisition circuit, which includes a second operational amplifier, a non-inverting input terminal of the second operational amplifier is electrically connected to a resistor R18 and a resistor R8 which are electrically connected to each other, an input terminal of a capacitor C13 is also connected between the connecting lines of the resistor R18 and the resistor R8, an output terminal of the capacitor C13 is electrically connected to an output terminal of the second operational amplifier, a non-inverting input terminal of the second operational amplifier is also electrically connected to a capacitor C18, and the capacitor C18 is grounded, and an input terminal of the acquisition unit is electrically connected to an output terminal of the line break detection and DC coupling unit.
4. The equal phase acquisition system for vibration signals of a hydropower unit according to claim 1 is characterized in that: The acquisition unit also includes a key phase output circuit, which includes: a central control module U11, a power output end of the central control module U11 is grounded through capacitors C46 and C49, a power input end of the central control module U11 is connected to a 24V voltage input, and the central control module U11 sets a limited current value through a resistor, and the current limit value is limited to a range of ≤50mA.
5. The equal phase acquisition system for vibration signals of a hydropower unit according to claim 1 is characterized in that: The isolation unit comprises: a power isolation unit and a signal isolation unit. The power isolation unit adopts two power isolation modules, and the signal isolation unit uses an ADIADuM series isolation IC to isolate the digital signal of the ADC.
6. The equal phase acquisition system for vibration signals of a hydroelectric unit according to claim 1 is characterized in that: The main control unit includes: an FPGA module and peripheral circuits. The FPGA module contains a specific program and can collect and output signals according to the program settings. The FPGA also includes a communication interface, which can connect other boards and a host computer. The host computer can configure PFGA to distribute signals.
7. The equal phase acquisition system for vibration signals of a hydroelectric unit according to claim 1 is characterized in that: The storage unit comprises an EEPROM chip, a power supply access terminal of the EEPROM chip is electrically connected to a power supply via a magnetic bead FB8, and the power supply access terminal of the EEPROM chip is grounded via a capacitor C95.
8. The equal phase acquisition system for vibration signals of a hydroelectric generator set according to claim 6 is characterized in that: The digital power supply includes a 3.3V power rail and a 5V power rail, the 3.3V power rail is used for IO power supply and isolation IC, and the 5V power rail is used to power the FPGA module; The analog power supply includes an isolated power supply and other power supplies. The isolated power supply includes two Jinshengyang power modules. The input voltage of the Jinshengyang power modules is 24V, and the output voltage is ±12V and ±24V; the other power supplies are converted and output from the two Jinshengyang power modules.
9. The equal phase acquisition system for vibration signals of a hydroelectric generator set according to claim 1 is characterized in that: It also includes a signal matrix unit, which includes: a key phase board module and an external device module, the key phase board module includes multiple key phase input terminals and multiple key phase output terminals, the external device module includes multiple input terminals, when the external device module needs a zero point of the key phase signal seat time, the signal is introduced into the external device module through a connecting line, and the signal matrix unit is configured with a signal matrix function.
10. The equal phase acquisition system for vibration signals of a hydroelectric generator set according to claim 1, characterized in that: Also includes: ADC module, the ADC module is configured in serial mode, a passive RC filter is configured at the input end of the ADC module to filter out noise outside the high-frequency band, and the four channels of the ADC module are used for collecting input boards.