Multi-parallel frequency converter control system and method for high-capacity compressed air energy storage

Abstract

A multi-parallel frequency converter control system and method for large-capacity compressed air energy storage belongs to the technical field of data processing, and comprises the following steps: if all frequency converters on a current target electrical wiring system are indicated to work in compliance under the condition that all instant working parameters I are reasonable, all frequency converters are controlled to work in compliance under the condition; if the decision index is smaller than the decision index critical value, it is indicated that the similarity between the working parameter regression line equation and the corresponding working parameter reference regression line equation is not good, and it is indicated that the instant working parameter II of the corresponding main frequency converter is reasonable; however, it is also an abnormal throughout, it is confirmed that attention is paid to the frequency converter and the corresponding working parameters for display are preferentially handled in the PDA, so that workers can detect the working parameters of the corresponding frequency converter more emphatically, and the efficiency of finding out the working failure of the frequency converter is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of data processing, and in particular relates to a multi-parallel inverter control system and method for large-capacity compressed air energy storage. Background Art

[0002] Compressed-Air Energy Storage (CAES) refers to a storage method that uses electrical energy to compress air during the low-load period of the power grid, seals the air at high pressure in abandoned mines, sunken seabed gas tanks, caves, expired oil and gas wells or newly built gas storage wells, and releases the compressed air to drive steam turbines to generate electricity during the peak load period of the power grid.

[0003] On the other hand, compressed air energy storage requires the use of inverters in a parallel system (inverter is a frequency conversion device). As mentioned in the prior art solution with patent publication number "CN116707012B", several inverters for compressed air energy storage are arranged side by side to form a parallel structure. One inverter is configured on a compression line, and each compression line is sequentially configured with a first-stage compressor, a second-stage compressor and a third-stage compressor connected to the inverter configured on the compression line. Accordingly, after the first-stage compressor and the second-stage compressor are switched to the high-voltage compressor transformer for power supply, the third-stage compressor of each compression line is driven by the inverter configured on the compression line.

[0004] It can be seen that the role of the frequency converter is very critical, and its performance status needs to be understood in real time. Therefore, the method often used in the prior art for detecting the performance status of the frequency converter during compressed air energy storage is: sampling the working parameters of each frequency converter during compressed air energy storage through various measuring equipment and displaying them on the worker's PDA, which is convenient for the worker to perform real-time inspection. As long as an abnormality occurs, a corresponding warning will be issued. However, under this method, because the parameters displayed on the PDA are very complicated, it is difficult for the worker to find the precursor of the frequency converter failure (the frequency converter failure may be the failure conditions such as frequency converter overload, frequency converter overheating or frequency converter grounding short circuit) from the parameters, and the frequency converter is often already failed when the warning is issued, which will lead to poor efficiency in finding the frequency converter failure. Summary of the invention

[0005] In order to solve the defects in the prior art, the present invention proposes a multi-parallel inverter control system and method for large-capacity compressed air energy storage, which effectively avoids the defects in the prior art that it is difficult for workers to find the precursor of inverter failure from the working parameters of the inverter used for compressed air energy storage, and the inverter often fails when the alarm is issued, resulting in low efficiency in finding inverter failure.

[0006] The present invention utilizes the following technical solutions.

[0007] A multi-parallel inverter control method for large-capacity compressed air energy storage, comprising: After the first-stage compressor and the second-stage compressor are switched to the high-voltage compressor transformer for power supply, the third-stage compressor of each compression line is driven by the frequency converter configured on the compression line for compressed air energy storage; The measuring device samples the working parameters of the inverter and transmits them to the controller. The controller analyzes the sampled working parameters of the inverter to confirm the performance of the inverter and transmits the performance and working parameters of the inverter to the PDA for display. The method of analyzing the working parameters of the inverter transmitted by the controller to confirm the performance status of the inverter includes: Step 1, obtaining the instantaneous working parameter 1 of the frequency converter corresponding to each compression line in the target electrical wiring system of the large compressed air energy storage power station sampled in the current time period; Step 2, under the condition that all the immediate working parameters are reasonable, one or more main inverters that are likely to fail after the current time period are identified based on the target inverters that are likely to fail in each inverter and the corresponding target failure time period; Step 3, according to the instant working parameter 2 of each main inverter in the pre-defined time period before the current time period, under the condition that each instant working parameter 2 is reasonable, according to each instant working parameter 2, determine the working parameter regression line equation of the corresponding main inverter; Step 4, calculate the resolution index of the working parameter regression line equation and the corresponding working parameter baseline regression line equation. If the resolution index is less than the pre-defined resolution index critical value, the corresponding main inverter is identified as the important inverter, and the working parameters for display of the important inverter in the worker's PDA are prioritized.

[0008] Further, in step 1, the instantaneous working parameter 1 of the frequency converter corresponding to each compression line is a parameter cluster formed by more than one type of working parameters of the corresponding frequency converter.

[0009] Furthermore, step 2 specifically includes: after obtaining the real-time working parameter 1 of each inverter transmitted by sampling, each real-time working parameter 1 is transmitted to the worker's PDA for display, and then each type of working parameter in the real-time working parameter 1 is compared with the reasonable parameter range of the corresponding type. If it is within the reasonable parameter range of the corresponding type, it is confirmed that the working parameter of the corresponding type is reasonable. If all types of working parameters are reasonable, it is determined that the corresponding real-time working parameter 1 is reasonable, that is, each real-time working parameter 1 is reasonable.

[0010] Furthermore, step 2 specifically includes: when all current working parameters are reasonable, based on the past failure entries of the target electrical wiring system, the past failure entries include the time when each inverter of the target electrical wiring system had working failures in the past and the working parameters of a single type with abnormalities, the past failure entries are stored in the controller, and the display frequency of past working failures of each inverter is summed up, and in order of the display frequency from high to low, a corresponding number of inverters are selected in each inverter to confirm as the target inverter that is prone to working failure.

[0011] Furthermore, step 2 specifically also includes: based on past failure entries, confirming the past time periods in which each target inverter failed in the past, totaling the display frequency two of each past time period in order of the display frequency two from high to low, and selecting the past time period with number two from each past time period to confirm it as the target failure time period of the corresponding target inverter, that is, the time period that is prone to work failure.

[0012] Further, step 2 specifically includes: calculating the weight 1 of each target frequency converter and the weight 2 of each corresponding target failure time period, the weight 1 being the ratio of the appearance frequency 1 of each target frequency converter divided by the cumulative value of the appearance frequency 1 of all target frequency converters, and the weight 2 being the ratio of the appearance frequency 2 of the corresponding single target failure time period of the target frequency converter divided by the cumulative value of the appearance frequency 2 of all corresponding target failure time periods; then, based on the weight 1 and the corresponding weight 2, confirming one or more main frequency converters that are prone to work failure after the current time period, confirming when The method for identifying one or more main frequency converters that are prone to work failure after a previous time period is as follows: the target frequency converters that work in the current time period and those in the corresponding target failure time periods are identified as key frequency converters, and the target failure time period that includes the target frequency converters that work in the current time period is identified as key failure time period; then, the product value 1 obtained by multiplying the weight 1 of each key frequency converter with the weight 2 of the corresponding key failure time period is calculated; if the product value 1 is higher than a pre-defined product value critical value, the corresponding key frequency converter is identified as the main frequency converter that is prone to work failure after the current time period.

[0013] Furthermore, step 3 specifically also includes: under the condition that each instant working parameter 2 is reasonable, indicating that the corresponding main inverter has not failed to work during the pre-defined time length, the same type of working parameters in each instant working parameter 2 are selected, and the working parameter is used as the dependent variable and the sampling time of the working parameter is used as the independent variable through the least squares method, so as to obtain the working parameter regression line equation of each main inverter.

[0014] Furthermore, the method in which the controller analyzes the operating parameters of the frequency converter transmitted by sampling to confirm the performance status of the frequency converter also includes: Step 5, if there is any abnormality in the instant working parameter, the corresponding inverter is confirmed as an abnormal inverter, the compression line where the abnormal inverter is located is confirmed as an abnormal compression line, and when the third-stage compressor of the abnormal compression line works properly, the target abnormal type of the abnormal inverter is confirmed; Step 6, summing up the appearance frequencies of past working failures of the past abnormal types of the next inverter, and selecting three past abnormal types from each past abnormal type as the easy abnormal type in descending order of the appearance frequencies; Step 7, obtaining the compressed air energy storage status of each easily abnormal type of the subsequent inverter and the target abnormal type of the abnormal inverter, summing up the appearance frequency of compressed air energy storage working errors in the compressed air energy storage status, and selecting the compressed air energy storage working errors of number 4 from each compressed air energy storage working error to be identified as easily occurring errors according to the appearance frequency from high to low; Step 8, calculating the weight 3 of each easily abnormal type and the corresponding weight 4 of each easily erroneous type; Step 9: According to the weight three and the corresponding weight four, the working parameters for display of the latter frequency converter in the PDA are adjusted.

[0015] Further, step 8 specifically includes: calculating the weight 3 of each easily abnormal category and the corresponding weight 4 of each easily error-generating category, the weight 3 is the ratio obtained by dividing the appearance frequency 1 of each easily abnormal category by the cumulative value of the appearance frequency 1 of all easily abnormal categories, and the weight 4 is the ratio obtained by dividing the appearance frequency 2 of each easily error-generating category corresponding to the easily abnormal category by the cumulative value of the appearance frequency 2 of all easily error-generating categories; Step 9 specifically includes: calculating the sum of each weight 3 and the product value 2 of each corresponding weight 4, the sum is the sum of the product value 1 of the corresponding easily abnormal type, then performing accumulation on the sum of each product value 1, the accumulated amount is the final sum of the product values, if the final sum of the product values ​​is higher than the predefined critical value of the sum of the product value 1, the working parameter for display of the next inverter in the PDA is preferentially processed, and the processed working parameter is obtained; If the sum of the product value 1 is higher than the predefined sum of the product value 2 critical value, the corresponding easy abnormal type is confirmed as the relevant abnormal type, and then when the next inverter is the target inverter, the target failure time period corresponding to the next inverter is located after the current time period and is confirmed as the core abnormal time period, and the past occurrence frequency of the anomaly of each relevant abnormal type of the next inverter in the core abnormal time period is summed up. The higher the past occurrence frequency, the higher the probability of the corresponding relevant abnormal type appearing in the core abnormal time period. Calculate the weight five of each core abnormal period and the weight six of each corresponding related abnormal type, the weight five is the ratio of the appearance frequency two of each core abnormal period divided by the cumulative value of the appearance frequency two of all target failure time periods corresponding to the next inverter, the weight six is ​​the ratio of the past appearance frequency of each related abnormal type corresponding to the core abnormal period divided by the cumulative value of the past appearance frequency of all related abnormal types, then calculate the product value three obtained by multiplying the weight five of each core abnormal period by the weight six of each corresponding related abnormal type, then perform accumulation on each product value three corresponding to the same related abnormal type, so as to obtain the corresponding sum of the product value two, according to the sum of the product value two, arrange and adjust the related types of working parameters corresponding to each related abnormal type in the processed working parameters, so as to obtain the final parameter cluster, thereby achieving the adjustment of the working parameters for display of the next inverter in the PDA.

[0016] A multi-parallel inverter control system for large-capacity compressed air energy storage, comprising: A plurality of frequency converters for compressed air energy storage are arranged in parallel from left to right to form a parallel structure, one frequency converter is arranged on one compression line, and each compression line is sequentially provided with a first-stage compressor, a second-stage compressor and a third-stage compressor connected to the frequency converter arranged on the compression line; The frequency converter is also provided with a number of measuring devices, and the measuring devices and the WIFI module are connected to the controller. The controller is connected to the PDA configured for the worker in the WLAN via the WIFI module. The measuring devices are used to sample the working parameters of the frequency converter and transmit them to the controller. The controller is used to analyze the sampled working parameters of the frequency converter to confirm the performance status of the frequency converter and transmit the performance status and working parameters of the frequency converter to the PDA for display. The modules running on the controller include: Parameter module 1, which is used to obtain the real-time working parameters of the inverters corresponding to each compression line in the electrical wiring system of the large compressed air energy storage power station sampled in the current time period; A failure module is used to identify one or more main frequency converters that are likely to fail after the current time period based on the target frequency converters that are likely to fail in each frequency converter and the corresponding target failure time period when all the current working parameters are reasonable; A confirmation module is used to confirm the working parameter regression line equation of the corresponding main inverter according to the instant working parameter 2 in the pre-defined time period before the current time period of each main inverter, under the condition that each instant working parameter 2 is reasonable; A processing module is used to obtain the resolution index of the working parameter regression line equation and the corresponding working parameter baseline regression line equation. If the resolution index is less than the pre-defined resolution index critical value, the corresponding main inverter is identified as an important inverter, and the working parameters of the important inverter for display in the worker's PDA are given priority processing.

[0017] The beneficial effects of the present invention are that, compared with the prior art, the technical effects of the present invention include: If all the current working parameters are reasonable, it means that all the inverters on the current target electrical wiring system are working properly. Under this condition, the target inverter that is prone to work failure and the corresponding target failure time period are identified, and the probability of the target inverter having work failure after the current time period is analyzed based on this, so as to identify the main inverter from it, and then perform focused analysis on the working parameters of the main inverter in the pre-defined time period before the current time period. If the resolution index is less than the resolution index critical value, it means that the working parameter regression line equation and the corresponding working parameter baseline regression line equation are not similar, indicating that even if the current working parameters of the corresponding main inverter are reasonable, they are often abnormal precursors. Therefore, the main inverter is identified and the corresponding working parameters for display are prioritized in the PDA (the priority treatment is to confirm the performance status of the inverter and transmit the performance status of the inverter to the PDA for display), so that the worker can perform more focused detection on the working parameters of the corresponding inverter, so as to improve the efficiency of finding inverter work failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a partial flow chart of the multi-parallel inverter control method for large-capacity compressed air energy storage described in the present invention; Figure 2 It is a partial structural diagram of the multi-parallel inverter control system for large-capacity compressed air energy storage described in the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely express the technical solution of the present invention. The embodiments expressed in this application are only partial embodiments of the present invention, not all embodiments. According to the spirit of the present invention, other embodiments obtained by technicians in this field without making creative work are all within the protection scope of the present invention.

[0020] like Figure 1 As shown, the multi-parallel inverter control method for large-capacity compressed air energy storage described in the present invention includes: After the first-stage compressor and the second-stage compressor are switched to the high-voltage compressor transformer for power supply, the third-stage compressor of each compression line is driven by the inverter for compressed air energy storage configured on the compression line; the inverter for compressed air energy storage often drives the third-stage compressor of each compression line in order from left to right.

[0021] The measuring device samples the working parameters of the inverter and transmits them to the controller. The controller analyzes the sampled working parameters of the inverter to confirm the performance of the inverter and transmits the performance and working parameters of the inverter to the PDA for display. A method for confirming the performance status of the inverter by analyzing the working parameters of the inverter transmitted by the controller through sampling, the method being executed on the controller and comprising: Step 1, obtain the real-time working parameters of the frequency converter of each compression line corresponding to the electrical wiring system of the large compressed air energy storage power station (the corresponding is configured on the compression line) transmitted by the current time period sampling; the current time period is a time period from now, and the size of the current time period can be determined according to requirements, such as 2 seconds, 3 seconds or 5 seconds. The sampling speed of the working parameters of the frequency converter of the measuring device can be one millisecond.

[0022] The number of electrical wiring systems of a large-scale compressed air energy storage power station is more than one. Here, each compression line of the electrical wiring system of the large-scale compressed air energy storage power station corresponds to (the correspondence is configured on the compression line) a frequency converter to achieve the driving of the third-stage compressor by the compression line. The target electrical wiring system is an electrical wiring system that is currently working in the large-scale compressed air energy storage power station and is to execute the corresponding parameters of the frequency converter that drives the third-stage compressor to confirm the performance status of the frequency converter. The number of target electrical wiring systems is more than one. In addition, in a preferred but non-restrictive embodiment of the present invention, in step 1, the instantaneous working parameter one of the frequency converter corresponding to each compression line is a parameter cluster formed by one or more types of working parameters of the corresponding frequency converter. Different frequency converters have different corresponding instantaneous working parameters one. The measuring equipment includes power sensor 1, power sensor 2, voltage sensor 1 and voltage sensor 2. Power sensor 1, power sensor 2, voltage sensor 1 and voltage sensor 2 are respectively used for synchronously sampling (the synchronization means that the sampling time of each sensor is the same) the input power of the inverter, the output power of the inverter, the input voltage of the inverter and the output voltage of the inverter. The real-time working parameter 1 includes the input power of the inverter, the output power of the inverter, the input voltage of the inverter and the output voltage of the inverter in the current time period, etc., which can determine whether the inverter is invalid.

[0023] When the target electrical wiring system starts working, the worker can transmit the start instruction of parameter detection during compressed air energy storage to the controller through the PDA software. The controller obtains different types of working parameters of the inverters in each compression line in the current time period through the measuring equipment, and finally obtains the real-time working parameters of the inverters corresponding to each compression line.

[0024] Step 2, under the condition that all the immediate working parameters are reasonable, one or more main inverters that are likely to fail after the current time period are identified based on the target inverters that are likely to fail in each inverter and the corresponding target failure time period; In a preferred but non-limiting embodiment of the present invention, step 2 specifically includes: after obtaining the instantaneous working parameter 1 of each frequency converter transmitted by sampling, each instantaneous working parameter 1 is transmitted to the worker's PDA for display, so that during the compressed air energy storage period, the worker can instantly understand the working conditions of each frequency converter. Then, the working parameters of each type in the instantaneous working parameter 1 and the reasonable parameter range of the corresponding type (the method for obtaining the reasonable parameter range of the corresponding type can be: that is, during the compressed air energy storage period of the same method and process in the past, the frequency converter to which the corresponding type of working parameter belongs is in a non-failure state (non-failure means that the frequency converter works in compliance) The minimum value and the maximum value of the corresponding type of working parameter sampled and transmitted by the measured device and the value between the minimum value and the maximum value are regarded as the reasonable parameter range of the corresponding type) are compared. If it is located in the reasonable parameter range of the corresponding type, it is confirmed that the working parameter of the corresponding type is reasonable. If all types of working parameters are reasonable, it is determined that the corresponding instantaneous working parameter 1 is reasonable, that is, each instantaneous working parameter 1 is reasonable.

[0025] In a preferred but non-restrictive implementation manner of the present invention, step 2 specifically also includes: when all, that is, each instant working parameter is reasonable, it indicates that all inverters on the target electrical wiring system in the current time period are working in compliance with regulations, based on the past failure entries of the target electrical wiring system (the past is the period before the current time), the past failure entries include the time when each inverter of the target electrical wiring system in the past produced working failures (the time may be the starting time of the inverter working failure) and abnormal single-type working parameters (the abnormal single-type working parameters are the working parameters of the type sampled and transmitted by the test equipment during the period when the inverter produced working failures, and the abnormal single type is the abnormal type), etc. The past failure entries are stored in the controller, and the display frequency of each inverter's past working failures is totaled (the display frequency may be the number of starting times when the inverter produced working failures). The higher the value of the display frequency, the more likely the corresponding inverter is to produce working failures. According to the order of the display frequency from high to low, the corresponding number of inverters are selected from each inverter to be confirmed as the target inverter that is prone to working failure. The size of number one can be determined according to specific requirements.

[0026] In a preferred but non-restrictive implementation of the present invention, step 2 specifically also includes: based on the past failure entries, confirm the past time periods in which each target frequency converter failed to work in the past, and add up the display frequency 2 of each past time period (the display frequency 2 of each past time period is the number of past failures of each target frequency converter in the past time period). The higher the display frequency 2, the easier it is for the target frequency converter to fail to work in the corresponding past time period. In order of the display frequency 2 from high to low, the past time period of number 2 is selected from each past time period to confirm it as the target failure time period of the corresponding target frequency converter, that is, the time period that is easy to fail to work. The size of number 2 can be determined according to specific requirements. The past time period is a number of time periods that are evenly divided according to the time period size defined by specific requirements during the working period of the target electrical wiring system in the past before the current time period.

[0027] In a preferred but non-restrictive implementation of the present invention, step 2 specifically also includes: calculating the weight 1 of each target frequency converter and the weight 2 of each corresponding target failure time period, the weight 1 being the ratio of the appearance frequency 1 of each target frequency converter divided by the cumulative value of the appearance frequency 1 of all target frequency converters, and the weight 2 being the ratio of the appearance frequency 2 of the corresponding single target failure time period of the target frequency converter divided by the cumulative value of the appearance frequency 2 of all corresponding target failure time periods; then, based on the weight 1 and the corresponding weight 2, confirming one or more main frequency converters that are prone to work failure after the current time period, confirming one or more main frequency converters that are prone to work failure after the current time period. The method is as follows: the target inverters that work in the current time period are identified as key inverters in the corresponding target failure time periods, and the target failure time periods that work in the current time period are identified as key failure time periods. Then, the product value 1 obtained by multiplying the weight 1 of each key inverter with the weight 2 of the corresponding key failure time period is calculated. The higher the product value 1 is, the more likely the corresponding key inverter will fail to work after the current time period. If the product value 1 is higher than the pre-defined product value critical value, it indicates that the corresponding key inverter is more likely to fail to work after the current time period, and the corresponding key inverter is identified as the main inverter that is likely to fail to work after the current time period. The pre-defined product value critical value can be set according to specific requirements.

[0028] Step 3, based on the instantaneous working parameter 2 of each compression line corresponding to the sampling of the test equipment (the correspondence is configured on the compression line) of each main inverter in the pre-defined time length before the current time period, under the condition that each instantaneous working parameter 2 is reasonable (the method for determining that the instant working parameter 2 is reasonable is the same as the method for determining that the instant working parameter 1 is reasonable), according to each instantaneous working parameter 2, confirm the working parameter regression line equation of the corresponding main inverter; the size of the pre-defined time length can be set according to specific requirements.

[0029] In a preferred but non-restrictive implementation of the present invention, step 3 specifically also includes: after the main inverter is confirmed, because the various types of working parameters of each inverter are obtained in real time, the real-time working parameter 2 of each main inverter in the pre-defined time period before the current time period is obtained. Under the condition that each real-time working parameter 2 is reasonable, it indicates that the corresponding main inverter has not failed in the pre-defined time period. Then, the same type of working parameters in each real-time working parameter 2 are selected, and the working parameter is used as the dependent variable and the sampling time of the working parameter is used as the independent variable through the least squares method, so as to obtain the working parameter regression line equation of each main inverter.

[0030] Step 4, obtain the resolution index of the working parameter regression line equation and the corresponding working parameter reference regression line equation. If the resolution index is less than the pre-defined resolution index threshold, the corresponding main inverter is identified as an important inverter, and the working parameters of the important inverter for display in the worker's PDA are processed first. The resolution index threshold can be set according to specific requirements.

[0031] The working parameter regression line equation and the working parameter benchmark regression line equation of each type are obtained through the least square method, and the resolution index of the working parameter regression line equation and the working parameter benchmark regression line equation are obtained. The working parameter benchmark regression line equation is the working parameter regression line equation of the inverter that has never had any working failure (the regression line equation is: the working parameter is taken as the dependent variable and the sampling time of the working parameter is taken as the independent variable through the least square method, so as to obtain the working parameter benchmark regression line equation). If the resolution index is less than the pre-defined critical value of the resolution index, it means that the working parameter regression line equation and the corresponding working parameter benchmark regression line equation are not similar enough, indicating that even if the real-time working parameters of the corresponding main inverter are reasonable, the probability of its working failure is not small. The corresponding main frequency converter is identified as the important frequency converter, that is, the frequency converter whose working condition is to be paid special attention to, and then the working parameters for display of the important frequency converter displayed in the worker's PDA are given priority (the priority treatment can be to mark the working parameters in yellow for display). The PDA also displays the working parameters for display of frequency converters other than the important frequency converter. Here, the working parameters for display immediately reflect the working condition and performance condition of the corresponding frequency converter. In the present invention, the working parameters for display of the important frequency converter are given priority. When there are many frequency converters in the target electrical wiring system, the frequency converter with abnormal floating signs in the working parameters can be efficiently found. In this way, in the face of the prompt before the frequency converter fails, the frequency converter can be maintained to avoid being adversely affected by the working performance of the frequency converter during compressed air energy storage.

[0032] In a preferred but non-limiting embodiment of the present invention, a method in which a controller performs analysis on a sampled working parameter of the frequency converter to confirm the performance status of the frequency converter is executed on the controller and further includes: Step 5, if the instant working parameter 1 is abnormal (if there is a condition in the working parameter of the instant working parameter 1 that is not in the reasonable parameter range of the corresponding type, the working parameter of the type is determined to be abnormal, that is, the instant working parameter 1 is abnormal), the corresponding inverter is determined as an abnormal inverter, and the compression line where the abnormal inverter is located is determined as an abnormal compression line, and when the third-stage compressor of the abnormal compression line works correctly (working correctly means that the work of the inverter driving the third-stage compressor is achieved correctly according to the plan), the target abnormal type of the abnormal inverter is determined; Step 6, sum up the appearance frequencies of past working failures of the past abnormal types of the next inverter (that is, the inverter adjacent to the right of the abnormal inverter in step 5), and select three past abnormal types as the easy abnormal types from each past abnormal type in order of the appearance frequencies from high to low; the size of the number three can be determined according to specific requirements.

[0033] Step 7, obtain only the compressed air energy storage status (the compressed air energy storage status is the working shutdown status of the compressed air energy storage during the operation of the inverter) of the subsequent inverter producing various types of abnormalities and the abnormal inverter producing the target type of abnormalities, sum up the display frequency two of the compressed air energy storage working errors (working error is the compressed air energy storage shutdown) in the compressed air energy storage status (the compressed air storage shutdown is one time, and the display amount two is automatically increased by one, and the initial value of the display amount two is zero), and in the order of the display frequency two from high to low, select the compressed air storage working errors of number four from each compressed air storage working error (each compressed air storage working error is the compressed air storage working error in the compressed air energy storage status under the abnormal conditions of each type of abnormality produced by the subsequent inverter and the abnormal conditions of each type of target abnormality produced by the abnormal inverter) to confirm it as an error that is easy to produce; the size of the number four can be determined according to specific requirements.

[0034] If there is an abnormal real-time working parameter 1 among each real-time working parameter 1, the corresponding inverter is confirmed as an abnormal inverter, and the compression line where the abnormal inverter is located is confirmed as an abnormal compression line. The abnormal prompt message of the abnormal inverter is synchronously transmitted to the PDA. If the current abnormal inverter drives the third-stage compressor to work correctly according to the plan, that is, the third-stage compressor of the abnormal compression line works correctly, it means that the current abnormal inverter working failure does not cause disadvantages to the third-stage compressor of the abnormal compression line. According to the abnormal types of various types of working parameters in the real-time working parameter 1, the type of abnormal processing inverter working failure is confirmed, that is, the target abnormal type. Just as the type with abnormality is the input power of the inverter, it means that the corresponding target abnormal type is the input power. The abnormal type of abnormal type is the abnormal input power of the inverter. The abnormal type is the abnormal type.

[0035] Then, based on the above past invalid items, the display frequency of the past abnormal type generated by the next inverter is counted (the display frequency of the past abnormal type is how many times the past abnormal type has appeared). The higher the display frequency is, the easier it is for the next inverter to display the corresponding past abnormal type. Here, the next inverter is the inverter in the compression line adjacent to the right of the abnormal compression line. The past abnormal type is the abnormal type that the work of the third-stage compressor driven by the next inverter is achieved correctly according to the plan. Then, according to the order of the display frequency from high to low, the number three past abnormal types are selected from each past abnormal type to be confirmed as the easy abnormal type, that is, the past abnormal type that is easy to appear.

[0036] Then, according to the entry of the compressed air energy storage status (the entry is the information of the previous compressed air energy storage shutdown status stored in the controller), the compressed air energy storage status under the abnormal conditions of various prone abnormal types produced by the subsequent inverter and the compressed air energy storage status under the abnormal conditions of the target abnormal type produced by the abnormal inverter are screened out, and the display frequency 2 of the compressed air storage operation error (operation error means compressed air storage shutdown) in the compressed air energy storage status is summed up (the compressed air storage is shut down once, and the display amount 2 will increase by one, and the initial value of the display amount 2 is zero). The higher the display frequency 2, the higher the probability of the corresponding compressed air storage shutdown. According to the order of the second frequency of appearance from high to low, after each compressed air energy storage working error (each compressed air energy storage working error is the compressed air energy storage working error in the compressed air energy storage state under the abnormal conditions of each easy abnormal type produced by the latter inverter and the abnormal conditions of each abnormal inverter producing the target abnormal type), the compressed air energy storage working error under the abnormal conditions of the number four is selected and confirmed as an error that is easy to occur; that is, when the corresponding abnormalities of the easy abnormal type and the target abnormal type appear together in the abnormality of the abnormal type that is easy to occur, the compressed air energy storage is more likely to have the problem of shutdown.

[0037] Step 8, calculating the weight 3 of each easily abnormal type and the corresponding weight 4 of each easily erroneous type; Step 9: According to the weight three and the corresponding weight four, the working parameters for display of the latter frequency converter in the PDA are adjusted.

[0038] In a preferred but non-limiting embodiment of the present invention, step 8 specifically includes: calculating the weight 3 of each easily abnormal category and the corresponding weight 4 of each easily error-prone category, the weight 3 is the ratio of the appearance frequency 1 of each easily abnormal category divided by the cumulative value of the appearance frequency 1 of all easily abnormal categories, and the weight 4 is the ratio of the appearance frequency 2 of each easily error-prone category corresponding to the easily abnormal category divided by the cumulative value of the appearance frequency 2 of all easily error-prone categories; Step 9 specifically includes: calculating the sum of each weight 3 and the product value 2 of each corresponding weight 4, the sum is the sum of the product value 1 of the corresponding easy abnormal type, the higher the sum of the product value 1, when the abnormal inverter produces the abnormality of the target abnormal type, the subsequent inverter produces the corresponding easy abnormal type of abnormality, the easier it is to cause the compressed air energy storage to work incorrectly, then perform accumulation on the sum of each product value 1, the amount obtained by the accumulation is the sum of the final product values, the higher the sum of the final product values, when the subsequent inverter produces the easy abnormal type of abnormality, the higher the probability of the compressed air energy storage to work incorrectly, if the final If the sum of the product values ​​is higher than the pre-defined product value sum threshold, the working parameters used for display of the next inverter in the PDA will be processed first, and the processed working parameters will be obtained (that is, the working parameters will be marked in yellow), so that the workers can track the real-time working status of the next inverter more efficiently. After seeing the yellow working parameters, the inverter to which the yellow working parameters belong can be maintained, that is, the maintenance can be performed efficiently, which can reduce the abnormality of the next inverter that is prone to abnormality and reduce the probability of the final compressed air energy storage operation error; the sum threshold can be set according to specific requirements.

[0039] If the sum of product value 1 is higher than the predefined critical value of the sum of product value 2, the critical value of the sum of product value 2 can be set according to specific requirements, indicating that the subsequent inverter is more likely to cause an error in the compressed air energy storage operation when the corresponding easy-to-abnormal type of abnormality occurs, the corresponding easy-to-abnormal type is confirmed as a related abnormal type, and then when the subsequent inverter is the target inverter, the target failure time period of the subsequent inverter corresponding to each target failure time period located after the current time period is confirmed as a core abnormal time period, and the past manifestation frequency of each related abnormal type of the subsequent inverter in the core abnormal time period is summed up (the past manifestation frequency is how many times the abnormality of each related abnormal type of the previous inverter in the core abnormal time period has appeared), the higher the past manifestation frequency, the higher the probability of the corresponding related abnormal type appearing in the core abnormal time period; Calculate the weight five of each core abnormal time period and the weight six of each corresponding related abnormal type. The weight five is the ratio of the appearance frequency two of each core abnormal time period divided by the cumulative value of the appearance frequency two of the corresponding all purpose failure time periods of the next inverter. The weight six is ​​the ratio of the past appearance frequency of each related abnormal type corresponding to the core abnormal time period divided by the cumulative value of the past appearance frequency of all related abnormal types. Then, calculate the product value three obtained by multiplying the weight five of each core abnormal time period by the weight six of each corresponding related abnormal type. Then, perform accumulation on each product value three corresponding to the same related abnormal type to obtain the sum of the corresponding product values ​​two. The higher the sum of the product values ​​two, the easier it is for the next inverter to produce after the current time period. The higher the probability of the compressed air energy storage working error of the corresponding related abnormality type, the higher the probability of the compressed air energy storage working error. According to the sum of the product value two, the corresponding related abnormality type in the processed working parameters are arranged and adjusted to obtain the final parameter cluster, thereby achieving the adjustment of the working parameters for display of the next inverter in the PDA. The higher the sum of the product value two, the front of the arrangement of the related working parameters of the corresponding related abnormality type, which is more convenient for workers to perform focused inverter failure detection. The front of the arrangement means that the abnormal precursor of the inverter failure to which the related working parameters belong is more obvious. Therefore, the order of the abnormal precursors can be efficiently executed in sequence, which is convenient to prevent the occurrence of related abnormality types.

[0040] If all the current working parameters are reasonable, it means that all the inverters on the current target electrical wiring system are working properly. Under this condition, the target inverter that is prone to work failure and the corresponding target failure time period are identified, and the probability of the target inverter having work failure after the current time period is analyzed based on this, so as to identify the main inverter from it, and then perform focused analysis on the working parameters of the main inverter in the pre-defined time period before the current time period. If the resolution index is less than the resolution index critical value, it means that the working parameter regression line equation and the corresponding working parameter baseline regression line equation are not similar, indicating that even if the current working parameters of the corresponding main inverter are reasonable, they are often abnormal precursors. Therefore, the main inverter is identified and the corresponding working parameters for display are prioritized in the PDA, so that the worker can perform more focused testing on the working parameters of the corresponding inverter, thereby improving the efficiency of finding inverter work failures.

[0041] like Figure 2 As shown, the multi-parallel inverter control system for large-capacity compressed air energy storage described in the present invention includes: A plurality of frequency converters for compressed air energy storage are arranged in parallel from left to right to form a parallel structure. One frequency converter is arranged on a compression line. Each compression line is sequentially provided with a first-stage compressor, a second-stage compressor and a third-stage compressor connected to the frequency converter arranged on the compression line. After the first-stage compressor and the second-stage compressor are switched to the high-voltage compressor transformer for power supply, the third-stage compressor of each compression line is driven by the frequency converter arranged on the compression line. The frequency converter for compressed air energy storage often drives the third-stage compressor of each compression line in the order from left to right.

[0042] The frequency converter is also provided with a number of measuring devices, and the measuring devices and the WIFI module are connected to the controller. The controller is connected to the PDA configured for the worker in the WLAN via the WIFI module. The measuring devices are used to sample the working parameters of the frequency converter and transmit them to the controller. The controller is used to analyze the sampled working parameters of the frequency converter to confirm the performance status of the frequency converter and transmit the performance status and working parameters of the frequency converter to the PDA for display. The modules running on the controller include: Parameter module 1, which is used to obtain the real-time working parameters of the inverters corresponding to each compression line in the electrical wiring system of the large compressed air energy storage power station sampled in the current time period; A failure module is used to identify one or more main frequency converters that are likely to fail after the current time period based on the target frequency converters that are likely to fail in each frequency converter and the corresponding target failure time period when all the current working parameters are reasonable; A confirmation module is used to confirm the working parameter regression line equation of the corresponding main inverter according to the instant working parameter 2 in the pre-defined time period before the current time period of each main inverter, under the condition that each instant working parameter 2 is reasonable; A processing module is used to obtain the resolution index of the working parameter regression line equation and the corresponding working parameter baseline regression line equation. If the resolution index is less than the pre-defined resolution index critical value, the corresponding main inverter is identified as an important inverter, and the working parameters of the important inverter for display in the worker's PDA are given priority processing.

[0043] The inverter failure may be caused by inverter overload, inverter overheating or inverter ground short circuit. The controller may be a single chip microcomputer or a PLC.

[0044] The beneficial effects of the present invention are that, compared with the prior art, the technical effects of the present invention include: If all the current working parameters are reasonable, it means that all the inverters on the current target electrical wiring system are working properly. Under this condition, the target inverter that is prone to work failure and the corresponding target failure time period are identified, and the probability of the target inverter having work failure after the current time period is analyzed based on this, so as to identify the main inverter from it, and then perform focused analysis on the working parameters of the main inverter in the pre-defined time period before the current time period. If the resolution index is less than the resolution index critical value, it means that the working parameter regression line equation and the corresponding working parameter baseline regression line equation are not similar, indicating that even if the current working parameters of the corresponding main inverter are reasonable, they are often abnormal precursors. Therefore, the main inverter is identified and the corresponding working parameters for display are prioritized in the PDA (the priority treatment is to confirm the performance status of the inverter and transmit the performance status of the inverter to the PDA for display), so that the worker can perform more focused detection on the working parameters of the corresponding inverter, so as to improve the efficiency of finding inverter work failures.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not deviate from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A multi-parallel inverter control method for large-capacity compressed air energy storage, characterized in that: include: After the first-stage compressor and the second-stage compressor are switched to the high-voltage compressor transformer for power supply, the third-stage compressor of each compression line is driven by the frequency converter configured on the compression line for compressed air energy storage; The measuring device samples the working parameters of the inverter and transmits them to the controller. The controller analyzes the sampled working parameters of the inverter to confirm the performance of the inverter and transmits the performance and working parameters of the inverter to the PDA for display. The method of analyzing the working parameters of the inverter transmitted by the controller to confirm the performance status of the inverter includes: Step 1, obtaining the instantaneous working parameter 1 of the frequency converter corresponding to each compression line in the target electrical wiring system of the large compressed air energy storage power station sampled in the current time period; Step 2, under the condition that all the immediate working parameters are reasonable, one or more main inverters that are likely to fail after the current time period are identified based on the target inverters that are likely to fail in each inverter and the corresponding target failure time period; Step 3, according to the instant working parameter 2 of each main inverter in the pre-defined time period before the current time period, under the condition that each instant working parameter 2 is reasonable, according to each instant working parameter 2, determine the working parameter regression line equation of the corresponding main inverter; Step 4, calculate the resolution index of the working parameter regression line equation and the corresponding working parameter baseline regression line equation. If the resolution index is less than the pre-defined resolution index critical value, the corresponding main inverter is identified as the important inverter, and the working parameters for display of the important inverter in the worker's PDA are prioritized.

2. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 1 is characterized in that: In step 1, the instantaneous working parameter 1 of the inverter corresponding to each compression line is a parameter cluster formed by more than one type of working parameters of the corresponding inverter.

3. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 2 is characterized in that: Step 2 specifically includes: after obtaining the real-time working parameter 1 of each inverter transmitted by sampling, each real-time working parameter 1 is transmitted to the worker's PDA for display, and then the working parameters of each category in the real-time working parameter 1 are compared with the reasonable parameter range of the corresponding category. If they are within the reasonable parameter range of the corresponding category, it is confirmed that the working parameters of the corresponding category are reasonable. If all categories of working parameters are reasonable, it is determined that the corresponding real-time working parameter 1 is reasonable, that is, each real-time working parameter 1 is reasonable.

4. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 3 is characterized in that: Step 2 specifically includes: when all current working parameters are reasonable, based on the past failure entries of the target electrical wiring system, the past failure entries include the time when each inverter of the target electrical wiring system had working failures in the past and the working parameters of each type with abnormalities, the past failure entries are stored in the controller, and the display frequency of the past working failures of each inverter is summed up, and in order of the display frequency from high to low, a corresponding number of inverters are selected in each inverter to be identified as the target inverter that is prone to working failure.

5. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 4 is characterized in that: Step 2 specifically also includes: based on past failure entries, confirming the past time periods in which each target inverter failed in the past, summing up the display frequency two of each past time period in order of the display frequency two from high to low, and selecting the number two past time periods from each past time period to confirm as the target failure time period of the corresponding target inverter, that is, the time period that is prone to work failure.

6. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 5 is characterized in that: Step 2 specifically also includes: calculating the weight 1 of each target frequency converter and the weight 2 of each corresponding target failure time period, the weight 1 is the ratio of the appearance frequency 1 of each target frequency converter divided by the cumulative value of the appearance frequency 1 of all target frequency converters, and the weight 2 is the ratio of the appearance frequency 2 of the corresponding single target failure time period of the target frequency converter divided by the cumulative value of the appearance frequency 2 of all corresponding target failure time periods; then, based on the weight 1 and the corresponding weight 2, confirming one or more main frequency converters that are prone to work failure after the current time period, the method for confirming one or more main frequency converters that are prone to work failure after the current time period is: confirming the target frequency converters that work in the current time period in the corresponding target failure time period as key frequency converters, and confirming the target failure time period of the target frequency converters that work in the current time period as key failure time periods, and then, calculating the product value 1 obtained by multiplying the weight 1 of each key frequency converter by the weight 2 of the corresponding key failure time period, if the product value 1 is higher than the pre-defined product value critical value, the corresponding key frequency converter is confirmed as the main frequency converter that is prone to work failure after the current time period.

7. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 6 is characterized in that: Step 3 specifically also includes: under the condition that all real-time working parameters 2 are reasonable, indicating that the corresponding main inverter has not failed to work during the pre-defined time length, the same type of working parameters in each real-time working parameter 2 are selected, and the working parameter is used as the dependent variable and the sampling time of the working parameter is used as the independent variable through the least squares method, so as to obtain the working parameter regression line equation of each main inverter.

8. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 7, characterized in that: The method in which the controller analyzes the working parameters of the frequency converter transmitted by sampling to confirm the performance status of the frequency converter also includes: Step 5, if there is any abnormality in the instant working parameter, the corresponding inverter is confirmed as an abnormal inverter, the compression line where the abnormal inverter is located is confirmed as an abnormal compression line, and when the third-stage compressor of the abnormal compression line works properly, the target abnormal type of the abnormal inverter is confirmed; Step 6, summing up the appearance frequencies of past working failures of the past abnormal types of the next inverter, and selecting three past abnormal types from each past abnormal type as the easy abnormal type in descending order of the appearance frequencies; Step 7, obtaining the compressed air energy storage status of each easily abnormal type of the subsequent inverter and the target abnormal type of the abnormal inverter, summing up the appearance frequency of compressed air energy storage working errors in the compressed air energy storage status, and selecting the compressed air energy storage working errors of number 4 from each compressed air energy storage working error to be identified as easily occurring errors according to the appearance frequency from high to low; Step 8, calculating the weight 3 of each easily abnormal type and the corresponding weight 4 of each easily erroneous type; Step 9: According to the weight three and the corresponding weight four, the working parameters for display of the latter frequency converter in the PDA are adjusted.

9. The multi-parallel inverter control method for large-capacity compressed air energy storage according to claim 8, characterized in that: Step 8 specifically includes: calculating the weight 3 of each easily abnormal category and the corresponding weight 4 of each easily error-prone category, the weight 3 is the ratio obtained by dividing the appearance frequency 1 of each easily abnormal category by the cumulative value of the appearance frequency 1 of all easily abnormal categories, and the weight 4 is the ratio obtained by dividing the appearance frequency 2 of each easily error-prone category corresponding to the easily abnormal category by the cumulative value of the appearance frequency 2 of all easily error-prone categories; Step 9 specifically includes: calculating the sum of each weight 3 and the product value 2 of each corresponding weight 4, the sum is the sum of the product value 1 of the corresponding easily abnormal type, then performing accumulation on the sum of each product value 1, the accumulated amount is the final sum of the product values, if the final sum of the product values ​​is higher than the predefined critical value of the sum of the product value 1, the working parameter for display of the next inverter in the PDA is preferentially processed, and the processed working parameter is obtained; If the sum of the product value 1 is higher than the predefined sum of the product value 2 critical value, the corresponding easy abnormal type is confirmed as the relevant abnormal type, and then when the next inverter is the target inverter, the target failure time period corresponding to the next inverter is located after the current time period and is confirmed as the core abnormal time period, and the past occurrence frequency of the anomaly of each relevant abnormal type of the next inverter in the core abnormal time period is summed up. The higher the past occurrence frequency, the higher the probability of the corresponding relevant abnormal type appearing in the core abnormal time period. Calculate the weight five of each core abnormal period and the weight six of each corresponding related abnormal type, the weight five is the ratio of the appearance frequency two of each core abnormal period divided by the cumulative value of the appearance frequency two of all target failure time periods corresponding to the next inverter, the weight six is ​​the ratio of the past appearance frequency of each related abnormal type corresponding to the core abnormal period divided by the cumulative value of the past appearance frequency of all related abnormal types, then calculate the product value three obtained by multiplying the weight five of each core abnormal period by the weight six of each corresponding related abnormal type, then perform accumulation on each product value three corresponding to the same related abnormal type, so as to obtain the corresponding sum of the product value two, according to the sum of the product value two, arrange and adjust the related types of working parameters corresponding to each related abnormal type in the processed working parameters, so as to obtain the final parameter cluster, thereby achieving the adjustment of the working parameters for display of the next inverter in the PDA.

10. A multi-parallel inverter control system for large-capacity compressed air energy storage, characterized in that: include: A plurality of frequency converters for compressed air energy storage are arranged in parallel from left to right to form a parallel structure, one frequency converter is arranged on one compression line, and each compression line is sequentially provided with a first-stage compressor, a second-stage compressor and a third-stage compressor connected to the frequency converter arranged on the compression line; The frequency converter is also provided with a number of measuring devices, and the measuring devices and the WIFI module are connected to the controller. The controller is connected to the PDA configured for the worker in the WLAN via the WIFI module. The measuring devices are used to sample the working parameters of the frequency converter and transmit them to the controller. The controller is used to analyze the sampled working parameters of the frequency converter to confirm the performance status of the frequency converter and transmit the performance status and working parameters of the frequency converter to the PDA for display. The modules running on the controller include: Parameter module 1, which is used to obtain the real-time working parameters of the inverters corresponding to each compression line in the electrical wiring system of the large compressed air energy storage power station sampled in the current time period; A failure module is used to identify one or more main frequency converters that are likely to fail after the current time period based on the target frequency converters that are likely to fail in each frequency converter and the corresponding target failure time period when all the current working parameters are reasonable; A confirmation module is used to confirm the working parameter regression line equation of the corresponding main inverter according to the instant working parameter 2 in the pre-defined time period before the current time period of each main inverter, under the condition that each instant working parameter 2 is reasonable; A processing module is used to obtain the resolution index of the working parameter regression line equation and the corresponding working parameter baseline regression line equation. If the resolution index is less than the pre-defined resolution index critical value, the corresponding main inverter is identified as an important inverter, and the working parameters of the important inverter for display in the worker's PDA are given priority processing.

Images