Static electronic speed measurement test method for generator

Abstract

The invention discloses a static electronic speed measurement test method for a generator, and the method comprises the steps: collecting the stator current, stator voltage and torque data of the generator in real time through a current sensor, a voltage sensor and a torque sensor, carrying out the short-time Fourier transform STFT processing of a rotor current signal, and obtaining a preliminary rotation speed estimation value; thirdly, deducing a more accurate rotating speed estimated value based on a self-adaptive algorithm in combination with electromagnetic characteristics of the motor; and finally, automatically adjusting the weights of the two speed measurement methods according to the dynamic or steady-state working condition of the generator by adopting a self-adaptive weighted fusion algorithm, and generating final rotating speed output. The problem that a traditional mechanical sensor is prone to being interfered is solved through the combined measurement method, and the response speed and the measurement precision of sensorless speed measurement under the dynamic working condition are improved.

Description

Technical Field

[0001] The invention relates to the technical field of generator control and measurement, and in particular to a static electronic speed measurement test method for a generator. Background Art

[0002] During the operation of the generator, accurate speed measurement is of great significance for the generator's status monitoring, fault diagnosis and performance optimization of the control system; however, traditional speed measurement methods mostly rely on mechanical sensors, such as photoelectric encoders or Hall sensors, which are complex and costly to install and are easily interfered by external environmental factors, resulting in reduced measurement accuracy; in addition, mechanical sensors also require regular maintenance and calibration, which increases the maintenance cost and downtime of the equipment; on the other hand, existing sensorless speed measurement methods usually have difficulty in providing sufficient measurement accuracy under dynamic conditions, especially in non-steady-state conditions such as rapid load changes or generator start-up and shutdown. Traditional methods are prone to large measurement errors or insufficient response speed.

[0003] Based on this, a static electronic speed measurement test method for the generator is needed. Summary of the invention

[0004] To achieve the above object, the present invention provides the following solution: a static electronic speed measurement test method for a generator, comprising the following steps: Step 1: Collect stator current from the stator and rotor electrical ports of the generator in real time through high-precision sensors , rotor current , stator voltage and torque The electromagnetic parameters are collected using high-precision current sensors, voltage sensors and torque sensors. These three sensors are connected to the embedded control system to continuously monitor and collect electromagnetic signals in real time during the operation of the generator. The signal is processed by short-time Fourier transform (STFT) to obtain the spectrum of the rotor current signal. , and extract the main frequency component through spectrum analysis , the main frequency component is proportional to the generator speed; According to the formula Calculate a preliminary estimate of the generator speed ; in, is the estimated value of the speed, in revolutions per minute (RPM). is the main frequency component extracted from the rotor current spectrum, is the number of pole pairs of the generator; Step 2: Based on the preliminary speed estimation completed in step 1, adaptive motor data acquisition is performed simultaneously to collect the stator current of the generator in real time , stator voltage and torque The data is transmitted to the embedded control system for real-time calculation, and the speed is derived through the electromagnetic characteristic model of the generator. ,use calculate; in, is the adaptive speed estimate in revolutions per minute (RPM). is the electromagnetic constant of the generator, and They are the stator voltage and stator current collected in real time, The electromagnetic torque of the generator is automatically adjusted under different loads and working conditions based on the collected stator voltage, stator current and torque data combined with the real-time operating status. ; Step 3: Calculate the sensorless speed estimate in steps 1 and 2 respectively and adaptive speed estimate Then, according to the sensorless speed measurement results And adaptive speed calculation results The adaptive weighted fusion algorithm is used to comprehensively process the measurement results of the two speeds. The adaptive weighted fusion algorithm dynamically adjusts the weights of the two speed measurement results according to the current working state of the generator. and , generating the final accurate speed output , the fusion formula is: ; Among them, the weight , under the dynamic condition of the generator, , give priority to increasing the sensorless speed estimation results Weight ; Under steady-state conditions, , increase the adaptive speed calculation result Weight , the final speed generated As the real-time speed data output of the generator.

[0005] Further preferably, the short-time Fourier transform (STFT) processing in step 1 includes processing the collected rotor current The signal is preprocessed at multiple levels, and the high-frequency and low-frequency noise in the signal is suppressed by digital filters to ensure the stability and continuity of the signal; the time-frequency analysis window is selected, and the window length is dynamically adjusted according to the operating speed and frequency range of the generator, which can accurately extract the main frequency component of the rotor current under different working conditions. In the process of extracting frequency components, the spectrum The main peaks in the generator are identified and the threshold is set according to the preset frequency range so that the extracted main frequency component is highly consistent with the actual generator speed.

[0006] Further preferably, the electromagnetic parameter collection in step 1 also includes the collection of the stator phase voltage and phase current of the generator, and the data of the phase voltage and phase current are used to supplement the stator voltage and stator current Information, improve the frequency content in sensorless speed measurement Extraction.

[0007] Further preferably, the adaptive motor data acquisition in step 2 is implemented by: Real-time acquisition of generator stator current and stator voltage , using the torque sensor to obtain the electromagnetic torque of the generator The torque sensor adopts dynamic measurement mode to reflect the change of torque in real time according to the load change. All collected electromagnetic data are calculated in real time by the embedded control system to adjust the electromagnetic constant. The numerical value of .

[0008] Further preferably, the torque The acquisition is carried out by a high-precision torque sensor, which provides torque data in real time under different load conditions; the signal output of the torque sensor is corrected by an error compensation algorithm.

[0009] Further preferably, the adaptive weighted fusion algorithm in step 3 dynamically adjusts the weight coefficient and Realize, adjust the weight value according to the real-time monitored load fluctuation rate and torque change rate, and give priority to the sensorless speed estimation results under dynamic conditions Weight , and in steady-state conditions, the adaptive speed estimation result is increased Weight .

[0010] Further preferably, when adjusting the weight coefficient, the operating environment data of the generator temperature, humidity, load state and mechanical vibration are collected and analyzed in real time by the embedded sensor, and the electromagnetic parameters of the generator are combined for fusion processing, and the embedded control system dynamically adjusts the sensorless speed measurement results according to the fluctuation of the environmental parameters. and adaptive measurement results The weight coefficient of .

[0011] Further preferably, the method continuously monitors the operating state of the generator through a monitoring module, and the monitoring module is based on the stator current , rotor current , stator voltage and torque Real-time data is used to calculate the efficiency and load of the generator.

[0012] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention performs spectrum analysis on the electrical parameters of the generator and extracts the frequency components related to the rotational speed to achieve non-contact rotational speed measurement; the adaptive speed measurement collects the stator current, stator voltage and electromagnetic torque data of the generator in real time, dynamically derives the rotational speed in combination with the electromagnetic characteristic model, and automatically adjusts the parameters according to the operating conditions to improve the measurement accuracy. The adaptive weighted fusion algorithm automatically adjusts the weights of the two speed measurement methods according to the dynamic or steady-state conditions of the generator in the two test methods, and can provide high-precision rotational speed measurement under different load conditions; In addition, the present invention monitors the environmental operating status of the generator through embedded sensors, optimizes the weight adjustment process, and ensures the stability of measurement in complex and changeable environments; overcomes the problem of traditional mechanical sensors being susceptible to interference through combined measurement methods, and improves the response speed and measurement accuracy of sensorless speed measurement under dynamic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0017] like Figure 1 As shown, the static electronic speed measurement test method for a generator in this embodiment includes the following steps: Step 1: Use multiple high-precision sensors to measure the electromagnetic parameters of the generator. The sensors are distributed at the stator and rotor ports of the generator to collect stator current. , rotor current , stator voltage and the electromagnetic torque of the generator The stator current and stator voltage are collected through the current sensor and voltage sensor at the stator end. The collection sensor has extremely high sensitivity and maintains linear output within different current ranges, ensuring the accuracy and real-time performance of data collection. The rotor current measurement requires the use of a dedicated non-contact current sensor to avoid interfering with the rotating part of the generator. The electromagnetic torque is measured by a high-precision torque sensor installed on the shaft, which can accurately reflect the torque changes of the generator under different load conditions. The sensor is connected to the embedded control system through a high-speed data acquisition module. The system monitors and collects electromagnetic signals in real time during the operation of the generator. The collection frequency is related to the operating status of the generator. When running at high speed, the collection frequency will increase accordingly to ensure a rapid response to speed changes. During stable operation, the sampling frequency can be appropriately reduced to reduce data redundancy and improve processing efficiency. Accurate electromagnetic parameter data can be obtained under various environments through the arrangement of these sensors. After these electromagnetic parameters are collected, especially the rotor current After preliminary filtering, the signal is processed by digital filter to suppress high-frequency noise and low-frequency interference in the signal to ensure the stability and continuity of the signal. The noise mainly comes from electromagnetic interference, environmental factors and mechanical noise in the operation of the generator. The purpose of eliminating noise is to obtain a clean and accurate current signal. After filtering, the rotor current The signal will be processed by short-time Fourier transform (STFT). STFT is a commonly used time-frequency analysis tool. By dividing the signal into several short-time windows and performing Fourier transform on the signals in these windows respectively, the time domain and frequency domain information of the signal can be obtained simultaneously. In the present invention, the time-frequency analysis window of STFT will be dynamically adjusted according to the operating speed and frequency range of the generator. The higher the operating speed of the generator, the shorter the length of the analysis window, so as to obtain a higher time resolution in the frequency analysis; when the operating speed of the generator is low, a longer analysis window is selected to improve the frequency resolution; when performing STFT processing, the rotor current The signal is divided into multiple short time segments. The length of each segment is dynamically determined according to the real-time operating status of the generator. The signal is Fourier transformed in each segment to generate the corresponding spectrum diagram. The spectrum diagram shows the frequency distribution of the signal in different time periods. By analyzing the spectrum diagram, the most significant main frequency component can be extracted. ; After extracting the main frequency component of the rotor current After that, the initial speed of the generator is estimated by the following formula:

[0018] Number of pole pairs of generator is a known constant, and by calculating the main frequency Get the estimated value of the generator speed .

[0019] Step 2: In this step, the stator current of the generator and stator voltage is the core electromagnetic parameter used to derive the speed estimate The torque of the generator is monitored in real time by a dynamic high-precision torque sensor installed on the shaft. The torque sensor adopts non-contact measurement method, which does not affect the normal operation of the generator. The torque sensor can provide real-time torque data under different load conditions, reflecting the impact of the load on the generator. When the load of the generator increases or decreases, the torque sensor can accurately capture the torque fluctuation and transmit the data to the embedded control system for processing; collect the stator current , stator voltage and torque After that, the adaptive speed estimation is performed in combination with the electromagnetic characteristic model of the generator. The electromagnetic characteristic model is based on electromagnetic parameters and the speed estimation value of the generator is derived by real-time monitoring of these parameters. , the estimated speed is calculated by the following formula:

[0020] Under static conditions, is considered a constant. In actual operation, especially when the load changes, It will change dynamically with the generator operating status, temperature changes, and electromagnetic field distribution factors. To ensure the accuracy of the measurement, the electromagnetic constant must be adjusted in real time. , to adapt to different loads and working conditions, by dynamically adjusting The value can be changed with the change of the generator operation status. The adjustment of electromagnetic constants is automatically completed through the embedded control system. The system automatically adjusts the current, voltage and torque data collected in real time and the operation status of the generator. The value of the speed can be accurately estimated under different loads, speeds and operating conditions by adjusting ; The signal output by the torque sensor is corrected through the error compensation algorithm. Since the torque sensor's measurement environment is affected by external factors such as mechanical vibration, ambient temperature changes, and electromagnetic interference, the measured value is prone to certain deviations. The embedded controller monitors the external influencing factors in real time and corrects the measured value through a preset error compensation model. For example, when the ambient temperature rises, the output of the torque sensor is affected by thermal noise, and the system can correct the sensor signal based on real-time temperature data; similarly, when the generator is subject to electromagnetic interference, the system can eliminate the interference signal through a noise filtering algorithm. During the operation of the generator, the speed fluctuation can be reflected in real time according to the change of load, especially when the load of the generator suddenly increases or decreases. The adaptive speed estimation can respond to this change quickly. Due to the electromagnetic constant It is dynamically adjusted according to the real-time working conditions, through rapid correction The value ensures that the speed estimation result is not affected by load fluctuations.

[0021] Step 3: In this step, the sensorless speed is estimated and adaptive speed estimation based on motor built-in data The present invention adopts an adaptive weighted fusion algorithm to dynamically adjust the sensorless speed estimation value according to the working state of the generator. and adaptive speed estimate The weight coefficient and , so that the final speed estimation value can not only respond quickly to changes in operating conditions, but also provide accurate measurement results under stable operating conditions; Sensorless speed estimation The speed is derived by analyzing the current frequency component of the generator, and it has the ability to respond quickly under dynamic conditions such as generator acceleration, deceleration or load fluctuations. Under these dynamic conditions, in order to capture the rapid changes in the generator speed in time, the sensorless speed estimation value will be increased first Weight , at this time the weighted fusion algorithm automatically adjusts Make it dominant and ensure that the speed measurement can respond to the changes in the generator's operating conditions in a timely manner; the formula is as follows:

[0022] in, , when the generator operating conditions change dramatically, the weight Increase, Reduce accordingly to improve dynamic response capability. Under steady-state conditions, the load and operating environment of the generator are relatively stable, and it will rely more on adaptive speed estimation. , since the adaptive speed estimation is based on the motor stator current , stator voltage , and torque The result calculated by the data has a high measurement accuracy, so under the condition that the generator runs relatively smoothly, the adaptive algorithm can provide a very accurate speed estimation value. At this time, the weight It occupies a large proportion in the fusion algorithm, ensuring that the system obtains high-precision speed measurement results under steady-state conditions. It monitors the environmental operating status of the generator through embedded sensors, and collects temperature, humidity, load fluctuations, and mechanical vibration external parameters. Because environmental data will affect the electromagnetic characteristics and operating efficiency of the generator, the system combines these environmental factors to estimate the weight of the speed. and Make dynamic adjustments; For example, when temperature or load changes suddenly, the system temporarily increases the sensorless speed estimation. The weight of the speed estimation is increased to ensure that the generator can respond quickly when the ambient conditions change; when the temperature and load are stable, the adaptive speed estimation is increased. The weight of the measurement is used to improve the measurement accuracy and fuse the results. It is the final speed output, which is output to the local display device for real-time monitoring by the operator. In addition, the system also transmits the data to the remote monitoring platform through the remote communication interface. The remote monitoring system can analyze the operating status of the generator based on the received real-time speed data.

[0023] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0024] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A static electronic speed measurement test method for a generator, characterized in that: The following steps are involved: Step 1: Collect stator current from the stator and rotor electrical ports of the generator in real time through high-precision sensors , rotor current , stator voltage and torque The electromagnetic parameters are collected using high-precision current sensors, voltage sensors and torque sensors. These three sensors are connected to the embedded control system to continuously monitor and collect electromagnetic signals in real time during the operation of the generator. The signal is processed by short-time Fourier transform (STFT) to obtain the spectrum of the rotor current signal. , and extract the main frequency component through spectrum analysis , the main frequency component is proportional to the generator speed; According to the formula Calculate a preliminary estimate of the generator speed ; in, is the initial estimated speed value in revolutions per minute (RPM). is the main frequency component extracted by STFT, is the number of pole pairs of the generator, the number of pole pairs of the generator is a known constant, and by calculating the main frequency Get the estimated value of the generator speed ; Step 2: Based on the preliminary speed estimation completed in step 1, adaptive motor data acquisition is performed simultaneously to collect the stator current of the generator in real time , stator voltage and torque The data is transmitted to the embedded control system for real-time calculation, and the speed is derived through the electromagnetic characteristic model of the generator. ,use Calculate adaptive speed estimate ; in, is the electromagnetic constant of the generator, and They are the stator voltage and stator current collected in real time, The electromagnetic torque of the generator is automatically adjusted under different loads and working conditions based on the collected stator voltage, stator current and torque data combined with the real-time operating status. ; Step 3: Calculate the sensorless speed estimate in steps 1 and 2 respectively and adaptive speed estimate After that, the adaptive weighted fusion algorithm is used to comprehensively process the measurement results of the two speeds. The adaptive weighted fusion algorithm dynamically adjusts the weights of the two speed measurement results according to the current working state of the generator. and , generating the final accurate speed output , the fusion formula is: ; Among them, the weight ; In the dynamic condition of the generator, it is preferred to increase the sensorless speed estimation result Weight , and under steady-state conditions, the calculation result of increasing the adaptive speed Weight , the final speed generated As the real-time speed data output of the generator.

2. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The short-time Fourier transform (STFT) processing in step 1 includes the acquisition of the rotor current The signal is preprocessed, and the high-frequency and low-frequency noise in the signal is suppressed by digital filters to ensure the stability and continuity of the signal; the time-frequency analysis window is selected, and the window length is dynamically adjusted according to the operating speed and frequency range of the generator to accurately extract the main frequency component of the rotor current under different working conditions In the process of extracting frequency components, the spectrum The main peaks in the generator are identified and the threshold is set according to the preset frequency range so that the extracted main frequency component is highly consistent with the actual generator speed.

3. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The electromagnetic parameter collection in step 1 also includes the collection of the stator phase voltage and phase current of the generator, and the data of the phase voltage and phase current are used to supplement the stator voltage and stator current Information, improve the frequency content in sensorless speed measurement Extraction.

4. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The adaptive motor data acquisition in step 2 is implemented by: Real-time acquisition of generator stator current and stator voltage , using the torque sensor to obtain the electromagnetic torque of the generator The torque sensor adopts dynamic measurement mode to reflect the change of torque in real time according to the load change. All collected electromagnetic data are calculated in real time by the embedded control system to adjust the electromagnetic constant. The numerical value of .

5. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The torque The acquisition is carried out by a high-precision torque sensor, which provides torque data in real time under different load conditions; the signal output of the torque sensor is corrected by an error compensation algorithm.

6. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The adaptive weighted fusion algorithm in step 3 dynamically adjusts the weight coefficients and Realize, adjust the weight value according to the real-time monitored load fluctuation rate and torque change rate, and give priority to increasing the sensorless speed estimation results under dynamic conditions Weight , and in steady-state conditions, the adaptive speed estimation result is increased Weight .

7. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: When adjusting the weight coefficient, the embedded sensor collects and analyzes the operating environment data of the generator temperature, humidity, load status and mechanical vibration in real time, and combines them with the electromagnetic parameters of the generator for fusion processing. The embedded control system dynamically adjusts the sensorless speed measurement results according to the fluctuations of environmental parameters. and adaptive measurement results The weight coefficient of .

8. The static electronic speed measurement test method for a generator according to claim 1, characterized in that: The method continuously monitors the operating state of the generator through a monitoring module, and the monitoring module is based on the stator current , rotor current , stator voltage and torque Real-time data is used to calculate the efficiency and load of the generator.

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