Wide-range frequency measuring device

Abstract

The utility model discloses a wide-range frequency measuring device, comprising a signal processing module which processes an input analog signal and outputs a digital pulse signal; the signal counting module is connected with the signal processing module, and the signal counting module counts and outputs a pulse value and a period value of the digital pulse signal; and the frequency calculation module is connected with the signal counting module, and the frequency calculation module calculates the frequency value of the digital pulse signal according to the pulse numerical value and the period value. According to the utility model, the high-precision measurement of signals in different frequency ranges is realized, the rapid response and anti-interference capabilities are realized, the high requirements of modern industry and energy fields on frequency measurement can be met, and the reliable guarantee is provided for the safe operation of rotating machinery.

Description

TECHNICAL FIELD

[0001] The utility model relates to a steam turbine monitoring and protection instrument technical field, especially a wide range frequency measuring device. BACKGROUND

[0002] In modern industry and energy field, the safe and stable operation of rotating machinery is crucial. The steam turbine monitoring and protection instrument (TSI) is an important equipment for real-time monitoring and diagnosis of rotating machinery, and one of its core functions is the accurate measurement of rotating machinery speed and frequency. The existing frequency measurement device faces the following main problems in actual application:

[0003] 1. Narrow measurement range

[0004] The existing frequency measurement device can usually only work within a limited frequency range. When the rotating machinery speed changes greatly, the existing device often fails to cover all possible frequency ranges, resulting in measurement limitations.

[0005] 2. Low precision

[0006] The precision of frequency measurement directly affects the state monitoring and fault diagnosis of rotating machinery. At present, the precision of most frequency measurement devices is not high enough to meet the demand for high-precision data. This may lead to the failure to discover potential fault risks in time, affecting the safe operation of equipment.

[0007] The main reason for the above phenomenon is the limitation of current frequency measurement technology. The existing measurement technology generally includes the following:

[0008] Counting measurement: count the input pulses to calculate the frequency. This method is usually used for high-frequency signal measurement, and its basic principle is to determine the frequency of the signal by counting the number of pulses input within a fixed time window. For example, using a time window, the counter counts the number of pulses within the window. By knowing the length of the time window, the frequency of the input signal can be calculated. Although the counting measurement method performs well in high-frequency signal processing, it is easily affected by noise interference and pulse jitter in actual application, thereby affecting the measurement precision. In addition, for low-frequency signals, the precision of counting measurement will decrease, because the number of pulses counted within a longer time window is less, resulting in an increase in frequency calculation error.

[0009] Period measurement: the frequency is calculated by measuring the period of the input signal. This method is commonly used for low-frequency signal measurement, and its basic principle is to determine the period by capturing the time interval between two consecutive rising edges (or falling edges) of the signal. For example, a timer can be used to start timing at the rising edge of the signal, and stop timing at the next rising edge, and the recorded time interval is the period of the signal, and the frequency is obtained by taking the reciprocal. The period measurement method performs well in low-frequency signal processing, because the period of low-frequency signal is longer, and high-precision frequency value can be obtained by accurate time measurement. However, this method has low measurement accuracy when processing high-frequency signals, because the period of high-frequency signal is short, and the resolution and reaction speed of the timer may not be sufficient to capture the rapidly changing signal. SUMMARY

[0010] According to the embodiment of the utility model, a wide range frequency measurement device is provided, which comprises:

[0011] The signal processing module processes the input analog signal and outputs a digital pulse signal.

[0012] The signal counting module is connected to the signal processing module, and counts and outputs the pulse value and period value of the digital pulse signal.

[0013] The frequency calculation module is connected to the signal counting module, and calculates the frequency value of the digital pulse signal according to the pulse value and period value.

[0014] Further, the signal processing module is a DC blocking shaping circuit, which is connected to the signal counting module, removes the DC component of the analog signal, and converts the analog signal into a digital pulse signal.

[0015] Further, the signal counting module comprises:

[0016] The pulse counting timer is connected to the signal processing module and the frequency calculation module, and counts the pulse value of the digital pulse signal.

[0017] The period measurement timer is connected to the signal processing module and the frequency calculation module, and counts the period value of the digital pulse signal.

[0018] Further, the signal counting module further comprises a master timer connected to the frequency calculation module, which periodically triggers the frequency calculation module and provides a time window for the pulse counting timer and the period measurement timer.

[0019] Further, it further comprises a denoising module connected to the frequency calculation module, which receives the frequency value and performs denoising processing.

[0020] Furthermore, the noise reduction module is a digital filter.

[0021] The wide-range frequency measuring device according to the present invention achieves high-precision measurement of signals in different frequency ranges, has fast response and anti-interference capabilities, can meet the high requirements of modern industry and energy fields for frequency measurement, and provides reliable protection for the safe operation of rotating machinery.

[0022] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a wide-range frequency measuring device according to an embodiment of the present invention. Detailed Implementation

[0024] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, further illustrating the present invention.

[0025] First, combine Figure 1 The present invention describes a wide-range frequency measuring device according to an embodiment of the present invention, which is used to measure signal frequency and has a wide range of applications.

[0026] like Figure 1 As shown, the wide-range frequency measurement device of this utility model embodiment includes: a signal processing module 1, a signal counting module, and a frequency calculation module 3.

[0027] Specifically, such as Figure 1 As shown, in this embodiment, signal processing module 1 processes the input analog signal and outputs a digital pulse signal; signal counting module is connected to signal processing module 1, and the signal counting module counts and outputs the pulse value and period value of the digital pulse signal; frequency calculation module 3 is connected to signal counting module, and the frequency calculation module 3 calculates the frequency value of the digital pulse signal based on the pulse value and period value. In this embodiment, signal processing module 1 uses an existing DC blocking and shaping circuit, which is connected to signal counting module. The DC blocking and shaping circuit removes the DC component of the analog signal and converts the input analog signal into a standard digital pulse signal. The shaped digital pulse signal has a clear rising edge and falling edge, ensuring the stability and accuracy of the signal for subsequent counting and capture.

[0028] Furthermore, such as Figure 1As shown, in the present embodiment, the signal counting module comprises: a pulse counting timer 21, which is connected with the signal processing module 1 and the frequency calculation module 3, and counts the pulse value of the digital pulse signal; a period measurement timer 22, which is connected with the signal processing module 1 and the frequency calculation module 3, and counts the period value of the digital pulse signal. By using the two timers for pulse counting and input capture at the same time, the measurement of high-frequency and low-frequency signals is applicable respectively. By combining the two measurement methods and comprehensively processing by the frequency calculation module 3, the accuracy and range of frequency measurement are improved. In the present embodiment, the signal counting module further comprises: a master timer 23, which is connected with the frequency calculation module 3, triggers the frequency calculation module 3 periodically, and provides the time window of the pulse counting timer 21 and the period measurement timer 22. By using the adjustable timing trigger mode, the operation of the frequency calculation module 3 is performed periodically, ensuring the real-time and continuity of frequency measurement, improving the response speed of the system, and providing flexible adjustment of the response time of frequency measurement.

[0029] In the present embodiment, the shaped pulse signal is sent to the pulse counting timer 21 for pulse counting. The pulse counting timer 21 counts the number of input pulses within the time window set by the master timer 23, generating a pulse value. The master timer 23 is used to start the time window for starting the pulse counter counting, and the pulse counter starts recording the number of input pulses within the set time window. When the time window ends, the pulse counter records the total number of pulses. By dividing the pulse number by the length of the time window, the frequency of the input analog signal is calculated. To prevent counting overflow, the pulse counting timer 21 is provided with an overflow interrupt, which records the number of each overflow, thereby widening the counting range and ensuring accurate counting of high-frequency signals.

[0030] The shaped pulse signal is also sent to the period measurement timer 22 for input capture. The function of the period measurement timer 22 is to accurately record the time when the rising edge or falling edge of the signal occurs. The master timer 23 is used to start the time window for starting the period measurement timer 22, and the period measurement timer 22 starts capturing the rising edge (or falling edge) of the signal and records the current timestamp. At the next rising edge (or falling edge), the period measurement timer 22 records the timestamp and calculates the interval between the two timestamps as the period value. By calculating the difference between the two timestamps, the period value of the signal is obtained. To prevent timing overflow, the period measurement timer 22 is provided with an overflow interrupt, which records the number of each overflow, thereby widening the timing range and ensuring accurate capture of low-frequency signals.

[0031] The master timer 23 is used to set a fixed periodic time to periodically trigger the operation of the frequency calculation module 3. The timing period of the master timer 23 can be set as needed to ensure the real-time and continuous nature of the frequency calculation. The master timer 23 is also responsible for providing the time window for the pulse counting timer 21 and the period counting timer to ensure the synchronous operation of each module.

[0032] The frequency calculation module 3 processes the count values ​​from the pulse counting timer 21 and the period values ​​from the period counting timer to calculate the frequency of the input signal. Using the pulse count value from the pulse counting timer 21 and the time window set by the main control timer 23, the frequency is calculated by dividing the number of pulses by the length of the time window to obtain the frequency value of the high-frequency signal. Using the time interval captured by the period counting timer, the frequency is calculated by the reciprocal of the period to obtain the frequency value of the low-frequency signal. The frequency calculation module 3 processes the frequency values ​​obtained from the pulse counting timer 21 and the period counting timer separately for high-frequency, mid-frequency, and low-frequency cases. For high-frequency signals, the result from the pulse counting timer 21 is used; for mid-frequency signals, the results from the pulse counting timer 21 and the period counting timer are combined; and for low-frequency signals, the result from the period counting timer is used. Existing microprocessors can be used for frequency calculation.

[0033] Furthermore, such as Figure 1 As shown, in this embodiment, it also includes: a noise reduction module 4, which is connected to the frequency calculation module 3. The noise reduction module 4 receives the frequency value and performs noise reduction processing. The noise reduction module 4 is a digital filter that uses digital filtering algorithms and smoothing processing to reduce noise interference and obtain a smoother and more stable frequency value, which is suitable for real-time monitoring and fault diagnosis.

[0034] Above, refer to Figure 1 This invention describes a wide-range frequency measuring device according to an embodiment of the present invention, which achieves high-precision measurement of signals in different frequency ranges, has fast response and anti-interference capabilities, can meet the high requirements of modern industry and energy fields for frequency measurement, and provides reliable protection for the safe operation of rotating machinery.

[0035] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes that element.

[0036] Although the content of the utility model has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A wide-range frequency measuring device, characterized by, The utility model relates to a signal processing device, comprising: a signal processing module for processing input analog signals and outputting digital pulse signals; a signal counting module connected to the signal processing module, the signal counting module counting and outputting the pulse value and cycle value of the digital pulse signals; a frequency calculation module connected to the signal counting module, the frequency calculation module calculating the frequency value of the digital pulse signals according to the pulse value and cycle value.

2. The wide-range frequency measuring device of claim 1, wherein The signal processing module is a DC isolation shaping circuit connected to the signal counting module, the DC isolation shaping circuit removing the DC component of the analog signals and converting the analog signals into digital pulse signals.

3. The wide-range frequency measuring device of claim 1, wherein The signal counting module comprises: a pulse counting timer connected to the signal processing module and the frequency calculation module, the pulse counter counting the pulse value of the digital pulse signals; a cycle measurement timer connected to the signal processing module and the frequency calculation module, the cycle measurement timer counting the cycle value of the digital pulse signals.

4. The wide-range frequency measuring device of claim 3, wherein The signal counting module further comprises a master timer connected to the frequency calculation module, the master timer periodically triggering the frequency calculation module and providing the time window of the pulse counting timer and the cycle measurement timer.

5. The wide-range frequency measuring device of claim 1, wherein The utility model further comprises a denoising module connected to the frequency calculation module, the denoising module receiving the frequency value and performing denoising processing.

6. The wide-range frequency measuring device of claim 5, wherein The denoising module is a digital filter.

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