An output voltage and mains power adaptive synchronization system

Abstract

The present invention relates to the field of voltage control technology, specifically to an output voltage and mains adaptive synchronization system. In the present invention, by collecting the amplitude and phase data of the mains voltage, and combining the disturbance information on the load side, a disturbance weight set is established, which can realize the quantitative analysis of the impact of the mains fluctuation, thereby improving the perception of the mains change trend, so that the regulation strategy can be adaptively adjusted for specific disturbance events. Based on the weight set, the disturbance probability of the future short period is calculated, and the mains fluctuation range is predicted in combination with the UPS output data, so that the amplitude or phase compensation strategy can be adjusted in advance, which improves the response speed of the power supply system to the mains fluctuation and reduces the impact of sudden fluctuations on the load. The amplitude and phase of the UPS output are sampled at multiple frequencies, and converted to a unified reference system using a coordinate transformation method, which can ensure that the amplitude and phase information of each frequency component are compared under the same coordinate reference.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage control, and in particular to an output voltage and mains power adaptive synchronization system. Background Art

[0002] An output voltage and mains adaptive synchronization system refers to an electric power system that can adjust the output voltage and achieve synchronous regulation according to the fluctuation of the mains voltage. The system mainly aims at the voltage matching problem between the mains power supply and the power supply equipment, covering technologies such as voltage detection, power conversion, and synchronous control. Its core working method includes: using a voltage sampling device to detect the mains voltage in real time, adjusting the output voltage to make it conform to the mains characteristics, and achieving phase matching with the mains through synchronous control.

[0003] The existing technology only samples the mains voltage in real time and adjusts the output voltage to match the mains, but fails to fully consider the disturbance characteristics of the mains, resulting in the lack of pertinence in the adjustment strategy of the UPS when dealing with complex power grid environments, and it is difficult to predict the mains fluctuations in advance, so that when a large voltage or phase offset occurs in a short period of time, the compensation effect may lag, affecting the stable operation of the load equipment. In addition, the existing technology only performs synchronization control based on the fundamental component, lacks multi-frequency sampling and analysis of the UPS output voltage waveform, and easily ignores the differences between different harmonic components, which may lead to insufficient adjustment ability of the UPS on high-order harmonic components, so that the harmonic mismatch problem between the UPS and the mains is not effectively solved, which may increase the harmonic pollution of the power grid and affect the overall power supply quality. In terms of synchronization judgment, the existing technology is mainly based on the static comparison of amplitude and phase, and fails to effectively evaluate the stability of the synchronization state. Even if the UPS meets the synchronization requirements in a short period of time, the synchronization state may drift due to load changes or mains fluctuations, thereby affecting the reliability of the long-term stable grid-connected operation of the UPS. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings in the prior art and to propose an output voltage and mains power adaptive synchronization system.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: an output voltage and mains power adaptive synchronization system comprises:

[0006] The disturbance weight setting module obtains the mains amplitude and phase data and load-end disturbance information in the substation system, analyzes the corresponding adjacent disturbance phenomena and sets the disturbance weights to generate a disturbance weight set;

[0007] The feedforward estimation execution module calculates the future disturbance probability according to the disturbance weight set, derives the mains power fluctuation range in the future specified period, determines the amplitude or phase compensation that needs to be executed in advance according to the mains power fluctuation range, and generates a voltage feedforward instruction set;

[0008] The phasor sampling conversion module applies the voltage feedforward instruction set to the UPS output terminal, obtains the UPS output voltage waveform and the mains voltage waveform and performs multi-frequency sampling, converts the sample sequence formed by the multi-frequency sampling to the same coordinate system through Park transformation, marks the main harmonic amplitude and phase, and generates a phasor waveform set;

[0009] The harmonic difference adjustment module compares the phasor deviation of the UPS output voltage waveform and the mains voltage waveform in the phasor waveform set on each main harmonic component, uses the phasor deviation as a real-time correction amount to further correct the UPS output voltage, and generates an output voltage adjustment result;

[0010] The adaptive synchronization generation module confirms the synchronization state between the UPS output voltage and the mains voltage in the output voltage adjustment result. If the synchronization requirement is met, it determines that the UPS output is adaptively synchronized with the mains, and generates an output voltage and mains adaptive synchronization result.

[0011] As a further solution of the present invention, the step of analyzing the corresponding adjacent disturbance phenomenon is specifically:

[0012] Obtain the mains amplitude and phase data and load-end disturbance information in the substation system, wherein the mains amplitude and phase data are collected by a voltage sampling device installed at the AC incoming line loop or the AC bus, and the load-end disturbance information is obtained by statistics of the operating data on the load side, generating a mains voltage change and load-end disturbance data set;

[0013] Based on the mains voltage change and load-end disturbance data set, adjacent disturbance phenomena corresponding to mains amplitude and phase changes, and adjacent disturbance phenomena corresponding to load-end disturbances are analyzed, and the correlation between different adjacent disturbance phenomena is calculated using the Pearson correlation coefficient to generate adjacent disturbance phenomenon analysis results.

[0014] As a further solution of the present invention, the step of obtaining the disturbance weight set is specifically:

[0015] Based on the analysis results of the adjacent disturbance phenomenon, the formula is adopted:

[0016] ,

[0017] ,

[0018] ;

[0019] In the analysis results of adjacent disturbance phenomena, the current The adjacent disturbance weight of a mains amplitude disturbance event among all mains amplitude disturbance events , the current The adjacent disturbance weight of a mains phase disturbance event among all mains phase disturbance events , the current The adjacent disturbance weight of a load-side current disturbance event among all load-side current disturbance events , obtain adjacent perturbation weights, integrate all of the adjacent perturbation weights to generate a perturbation weight set.

[0020] As a further solution of the present invention, the step of calculating the future disturbance probability is specifically:

[0021] Obtain UPS output amplitude and phase data of AC and DC power supplies, as well as AC power amplitude and phase change inputs, to generate UPS and AC power output data sets;

[0022] Based on the UPS and mains output data set and the disturbance weight set, the formula is used:

[0023] ,

[0024] ,

[0025] ;

[0026] Calculate the The probability of disturbance of the future mains amplitude at a time point , No. The probability of future mains phase disturbance at a time point , and The probability of future load-side disturbance at a time point , generating different sets of future perturbation probabilities.

[0027] As a further solution of the present invention, the steps of acquiring the voltage feedforward instruction set are specifically as follows:

[0028] According to the different future disturbance probability sets, deriving the mains power fluctuation interval in a future specified time period, and generating the mains power fluctuation information in the future time period;

[0029] The amplitude or phase compensation that needs to be performed in advance is determined according to the future mains power fluctuation interval derived from the mains power fluctuation information in the future period, and the UPS feedforward adjustment value is mapped to generate a voltage feedforward instruction set.

[0030] As a further solution of the present invention, the step of acquiring the phasor waveform set is specifically as follows:

[0031] Apply the UPS feedforward adjustment value corresponding to the voltage feedforward instruction set to the UPS output, obtain the UPS output voltage waveform and the mains voltage waveform and perform multi-frequency sampling, convert the sample sequence formed by the multi-frequency sampling to the d-axis and q-axis components of the same coordinate system through Park transformation, for the mains voltage waveform, obtain the phase of the mains voltage fundamental wave and set it as the reference phase, the d-axis is aligned with the mains voltage fundamental wave phase, and the q-axis is orthogonal to the mains voltage fundamental wave phase, for the UPS output voltage waveform, its reference phase is at the same frequency as the mains voltage fundamental wave phase, the d-axis represents the part of the UPS output voltage waveform that is in phase with the mains voltage fundamental wave phase, and the q-axis represents the part of the UPS output voltage waveform that is orthogonal to the mains voltage fundamental wave phase, and generate component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinate;

[0032] Based on the component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinates, the main harmonic amplitudes and phases in the UPS output voltage waveform and the mains voltage waveform are marked, and the harmonic amplitudes of the observable components in the UPS output voltage waveform and the mains voltage waveform other than the main harmonic amplitudes and phases are distinguished to generate a phasor waveform set.

[0033] As a further solution of the present invention, the step of obtaining the output voltage adjustment result is specifically:

[0034] Comparing the phasor deviations of the UPS output and the mains voltage in each main harmonic component in the phasor waveform set, and generating deviation information of the UPS output in each harmonic component;

[0035] The deviation information of the UPS output on each harmonic component is superimposed or merged into the amplitude and phase of the UPS output as a correction amount to generate an output voltage adjustment result.

[0036] As a further solution of the present invention, the step of obtaining the result of adaptive synchronization between the output voltage and the mains power is specifically:

[0037] Compare the amplitude and phase of the corrected UPS output on each frequency component in the output voltage adjustment result with the amplitude and phase of the mains voltage on the same frequency component one by one to generate a phase comparison result of the mains input;

[0038] According to the phasor comparison result of the AC power input, the synchronization state between the UPS output voltage and the AC power voltage is confirmed. If the synchronization requirements are met, the UPS output is determined to be adaptively synchronized with the AC power. When the UPS confirms the synchronization state, the UPS can be safely switched to the bypass mode to generate an output voltage and AC power adaptive synchronization result.

[0039] Compared with the prior art, the advantages and positive effects of the present invention are:

[0040] In the present invention, by collecting the amplitude and phase data of the mains voltage, and combining the disturbance information on the load side, a disturbance weight set is established, which can realize the quantitative analysis of the mains fluctuation impact, thereby improving the perception of the mains change trend, so that the regulation strategy can be adaptively adjusted for specific disturbance events. Based on the weight set, the disturbance probability of the future short period is calculated, and the mains fluctuation interval is predicted in combination with the UPS output data, so that the amplitude or phase compensation strategy can be adjusted in advance, which improves the response speed of the power supply system to the mains fluctuation and reduces the impact of sudden fluctuations on the load. The amplitude and phase of the UPS output are multi-frequency sampled, and converted to a unified reference system using a coordinate transformation method, which can ensure that the amplitude and phase information of each frequency component are compared under the same coordinate reference, improve the analysis accuracy of the UPS output voltage waveform, and ensure the consistency of the UPS compensation effect on each frequency component. Based on the phasor deviation of the UPS output and the mains voltage on each main harmonic component, the output amplitude and phase of the UPS are dynamically adjusted, so that the UPS can adapt to different mains harmonic characteristics, reduce the harmonic interference when the UPS is synchronized with the mains, and improve the compatibility of the power grid. When making the final synchronization judgment, not only is a static comparison made on the amplitude and phase of the UPS output, but the synchronization stability is also analyzed in combination with historical data to ensure the continuity of the UPS synchronization state, making it suitable for long-term operation power environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a system flow chart of the present invention;

[0042] Figure 2 A flow chart of the corresponding adjacent disturbance phenomenon analyzed by the present invention;

[0043] Figure 3 A flow chart of obtaining a disturbance weight set for the present invention;

[0044] Figure 4 A flow chart for calculating the probability of future disturbances for the present invention;

[0045] Figure 5 A flow chart for obtaining a voltage feedforward instruction set for the present invention;

[0046] Figure 6 A flow chart for obtaining a phasor waveform set according to the present invention;

[0047] Figure 7 A flow chart of obtaining an output voltage adjustment result of the present invention;

[0048] Figure 8 The present invention is a flow chart for obtaining the result of adaptive synchronization between the output voltage and the mains. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0050] See also Figure 1 , an output voltage and mains adaptive synchronization system comprising:

[0051] The disturbance weight setting module obtains the mains amplitude and phase data and load-end disturbance information in the substation system, analyzes the corresponding adjacent disturbance phenomena and sets the disturbance weights to generate a disturbance weight set;

[0052] The feedforward estimation execution module calculates the probability of future disturbances according to the disturbance weight set, derives the mains power fluctuation range within the specified future period, determines the amplitude or phase compensation that needs to be executed in advance according to the mains power fluctuation range, and generates a voltage feedforward instruction set;

[0053] The phasor sampling conversion module applies the voltage feedforward instruction set to the UPS output end, obtains the UPS output voltage waveform and the mains voltage waveform and performs multi-frequency sampling. The sample sequence formed by multi-frequency sampling is converted to the same coordinate system through Park transformation and the main harmonic amplitude and phase are marked to generate a phasor waveform set.

[0054] The harmonic difference adjustment module compares the phasor deviation of the UPS output voltage waveform and the mains voltage waveform in the phasor waveform set on each main harmonic component, and uses the phasor deviation as a real-time correction amount to further correct the UPS output voltage and generate an output voltage adjustment result;

[0055] The adaptive synchronization generation module confirms the synchronization state between the UPS output voltage and the mains voltage in the output voltage adjustment result. If the synchronization requirement is met, it determines that the UPS output is adaptively synchronized with the mains, and generates the output voltage and mains adaptive synchronization result.

[0056] See also Figure 2 , the specific steps for analyzing the corresponding adjacent disturbance phenomenon are:

[0057] Obtain the mains amplitude and phase data and load-end disturbance information in the substation system, wherein the mains amplitude and phase data are collected by a voltage sampling device installed at the AC incoming line loop or the AC bus, and the load-end disturbance information is obtained by statistics of the operating data on the load side, generating a mains voltage change and load-end disturbance data set;

[0058] First, a voltage sampling device is installed at the AC incoming line loop or AC bus, and a synchronous phasor measurement unit (PMU) is used for data collection. The PMU uses the GPS timing signal to ensure the synchronization of the sampling time across the entire network. The voltage signal of the three-phase AC power is low-pass filtered to remove high-frequency interference, and the analog-to-digital conversion (A / D conversion) technology is used to convert the analog voltage signal into a digital signal, extract the effective value and phase angle, and obtain the real-time voltage amplitude and phase data of the mains. At the same time, the voltage signal is decomposed into different time windows through short-time Fourier transform (STFT) to analyze the dynamic change characteristics of the mains voltage and provide basic data for subsequent disturbance analysis. On the other hand, the collection process of load-end disturbance information includes installing smart meters or digital relay protection devices on key load branches to measure load current, voltage, power and other parameters in real time. The collected data is uploaded to the monitoring center through the data acquisition terminal (RTU) or the intelligent monitoring system, and then the abnormal data is removed using data cleaning methods, such as The three sigma criterion is used to remove abnormal points that exceed the normal load range, and the sliding window averaging method is used to calculate the load current mean and standard deviation to evaluate the fluctuation of the load end. For example, within a set time window, if the standard deviation is between 0.1A and 0.3A, it indicates that the load current variation is within this range. If the standard deviation exceeds 0.3A, it indicates that the load current variation exceeds the reference range. If the standard deviation is lower than 0.1A, it indicates that the load current fluctuation is small. Compared with the reference range, the load current fluctuation can be further judged by calculating the time series change trend of the standard deviation. For example, within multiple time windows, if the standard deviation fluctuates within 5%, it can be determined that the load current change trend is relatively stable. If the standard deviation changes by more than 10% in different time windows, it indicates that the load current fluctuation trend has changed significantly. Therefore, it can be judged whether the load is in a stable operating state or has sudden fluctuations in combination with the specific load operation conditions.

[0059] Based on the mains voltage change and load-end disturbance data sets, the adjacent disturbance phenomena corresponding to the mains amplitude and phase changes, as well as the adjacent disturbance phenomena corresponding to the load-end disturbance are analyzed, and the correlation between different adjacent disturbance phenomena is calculated using the Pearson correlation coefficient to generate adjacent disturbance phenomenon analysis results;

[0060] First, the mains voltage amplitude and phase data are obtained, and the short-time Fourier transform (STFT) is used to analyze the voltage changes in different time windows to identify the mutation points of the mains fluctuations. The mutation points can be determined by setting voltage change thresholds. For example, the amplitude change in adjacent time windows exceeds 2% of the nominal voltage (for example, if the nominal voltage is 220V, the voltage fluctuation amplitude must exceed 4.4V), or the phase mutation exceeds 5°. Combined with the sliding window analysis method, the Pearson correlation coefficient is used to calculate the correlation between adjacent disturbances. In the sliding time window, the mains amplitude change time series and The covariance between the load current change time series is normalized to obtain the correlation between the disturbances. If the correlation coefficient is close to 1, it indicates that there is a strong correlation between the two. If it is close to -1, it indicates that the change trend is opposite. If it is close to 0, it indicates that there is no obvious relationship between the two. For example, during the operation of a substation, multiple disturbances occurred in the mains system. At a certain moment, the mains voltage amplitude dropped to less than 98% of the steady-state value within 20ms (that is, the amplitude decreased by more than 2%), and then within 1ms, the phase shifted by 2.5°. At this time, it is necessary to determine whether these fluctuations are related to each other. In order to confirm the correlation, the historical disturbance data within 100ms is used for comparison, the average phase shift before and after the voltage drop is calculated, and matched with the current disturbance event. If more than 80% of similar disturbances in the historical data (that is, the voltage drop exceeds 2%, and the phase change exceeds 2° within 1ms) show a highly correlated change trend, it can be preliminarily determined that the mains voltage mutation and the phase shift belong to the same disturbance category. Furthermore, the Pearson correlation coefficient is calculated. If the calculated correlation coefficient is greater than 0.85, it means that there is a strong correlation between the adjacent disturbance phenomena; if the correlation coefficient is less than 0.5, it means that it may be an independent disturbance event. For the analysis of the disturbance phenomenon at the load end, the change of the load current waveform can be monitored, and the energy characteristics of different frequency bands can be decomposed by wavelet transform, and the high-frequency and low-frequency components can be distinguished to identify different types of load fluctuations. If the current change of a load current change event exceeds 5% of the nominal current within 50ms (for example, if the rated load current is 100A, the change must exceed 5A), and this load current fluctuation and the fluctuation of the mains voltage are highly overlapped on the time axis (that is, the time interval between the two fluctuations is less than 2ms), it can be inferred that the load fluctuation may be the triggering factor of the mains disturbance. For example, in a factory power system, after a device with a rated current of 150A is started, the load current increases by 10A within 30ms, and within 2ms after the device is started, the AC voltage amplitude drops by 0.8V. At this time, further analysis can be performed by calculating the correlation between the load current fluctuation and the AC voltage change.If the change in load current is aligned with the transient drop time of the AC voltage, and the calculated correlation coefficient is above 0.85, it can be determined that the startup of the load device may be the main triggering factor of the AC disturbance. Finally, the time series, amplitude changes and phase offsets of these disturbance events are recorded for subsequent disturbance weight setting analysis.

[0061] See also Figure 3 , the specific steps for obtaining the perturbation weight set are:

[0062] Based on the analysis results of adjacent disturbance phenomena, the formula is adopted:

[0063] ,

[0064] ,

[0065] ;

[0066] In the analysis results of adjacent disturbance phenomena, the current The adjacent disturbance weight of a mains amplitude disturbance event among all mains amplitude disturbance events , the current The adjacent disturbance weight of a mains phase disturbance event among all mains phase disturbance events , the current The adjacent disturbance weight of a load-side current disturbance event among all load-side current disturbance events ;

[0067] in, It is the current one in the adjacent disturbance phenomenon analysis results. The voltage amplitude change of a mains amplitude disturbance event, unit: V, is calculated by: , Is the current After a mains amplitude disturbance event occurs ( ) Mains voltage at a certain point in time, unit: V, obtained by measuring the voltage value of the PMU device or voltage sensor. Is the current Before the mains amplitude disturbance event occurs ( ) Mains voltage at a certain point in time, in V, obtained by measuring the voltage value through the PMU device or voltage sensor. It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all mains amplitude disturbance events. The voltage amplitude change of a mains amplitude disturbance event, unit: V, acquisition method is the same as Same, for . It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of each mains amplitude disturbance event is obtained through Pearson correlation analysis. It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all mains amplitude disturbance events. The correlation coefficient of the mains amplitude disturbance events. It is the current one in the adjacent disturbance phenomenon analysis results. The phase change of a mains phase disturbance event, unit: °, is calculated by: , Is the current The mains phase angle at a certain time point after a mains phase disturbance event occurs, unit: °, obtained by the phase angle measured by the PMU device, Is the current The mains phase angle at a certain time point before a mains phase disturbance event occurs, in degrees, obtained by measuring the phase angle of the PMU device. It is the first phase disturbance event corresponding to the adjacent disturbance phenomenon analysis result when traversing all the mains phase disturbance events. Phase change of a mains phase disturbance event, unit: °, acquisition method is the same as Same, for , It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of the mains phase disturbance events. It is the first phase disturbance event corresponding to the adjacent disturbance phenomenon analysis result when traversing all the mains phase disturbance events. The correlation coefficient of the mains phase disturbance events. It is the current one in the adjacent disturbance phenomenon analysis results. The current change of a load-end current disturbance event, unit: A, is calculated by: , Is the current The load current at a certain time point after a load-end current disturbance event occurs, unit: A, the current value measured by the smart meter, Is the current The load current at a certain time point before a load-end current disturbance event occurs, unit: A, the current value measured by the smart meter. It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all load-side current disturbance events. The current change caused by a load-side current disturbance event. It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of the load-side current disturbance events. It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all load-side current disturbance events. The correlation coefficient of the load-side current disturbance events. Used to sum the calculated values ​​of all mains amplitude disturbance events and mains phase disturbance events. Used to sum the calculated values ​​of all load current disturbance events. It is the total number of all mains amplitude disturbance events or mains phase disturbance events in the adjacent disturbance phenomenon analysis results, which is obtained by counting the number of corresponding events that meet the disturbance criteria within a period of time. is the total number of load-side current disturbance events in the adjacent disturbance phenomenon analysis results. To iterate over all or different disturbance events to be summed.

[0068] Assuming the first mains amplitude disturbance event, the voltage amplitude change is: , correlation coefficient: The second mains amplitude disturbance event, voltage amplitude change: , correlation coefficient: ,but ,

[0069] .

[0070] Assuming the first mains phase disturbance event, the phase change is: , correlation coefficient: The second mains phase disturbance event, phase change: , correlation coefficient: ,but ,

[0071] .

[0072] Assuming the first load-end disturbance event, the current change is: , correlation coefficient: The second load-end disturbance event, current change: , correlation coefficient: ,but ,

[0073] .

[0074] Final calculation results:

[0075] Disturbance Type Event 1 Event 2 Mains amplitude disturbance weight 0.73 0.27 Mains phase disturbance weight 0.73 0.27 Load end disturbance weight 0.68 0.32

[0076] Integrate all adjacent perturbation weights to generate a perturbation weight set;

[0077] First, obtain the calculation results of all disturbance events and map the corresponding amplitude, phase and load current disturbance weights. Each disturbance event corresponds to three types of disturbance weights, and their data structure is stored as: ,

[0078] in: ,

[0079] , then, according to the disturbance event index The three types of disturbance weights corresponding to the same disturbance event are merged and archived uniformly to build a disturbance weight data structure, which is convenient for subsequent system adaptive adjustment and processing.

[0080] See also Figure 4 , the specific steps for calculating the probability of future disturbances are:

[0081] Obtain UPS output amplitude and phase data of AC and DC power supplies, as well as AC power amplitude and phase change inputs, to generate UPS and AC power output data sets;

[0082] First, the real-time voltage amplitude and phase information of the UPS output are recorded. The data acquisition frequency is set according to the UPS adjustment requirements, such as 1000 samplings per second. The sampled data is stored in the data cache of the UPS control system for subsequent analysis. At the same time, the amplitude and phase changes of the AC power are obtained through the synchronous measurement device (such as the synchronous phasor measurement unit PMU) installed at the AC input end. The device can record the voltage fluctuation and phase drift of the AC power. After data acquisition, it needs to undergo preliminary preprocessing, including removing transient interference signals, filtering, and adjusting data timing so that the UPS output data and the AC power input data are aligned on the same time axis. In addition, before data storage, it is necessary to perform a data integrity check on the UPS and AC power data to eliminate possible abnormal data points. Finally, the processed UPS output data and AC power input data are stored in the data cache.

[0083] Based on the UPS and mains output data set and the disturbance weight set, the formula is used:

[0084] ,

[0085] ,

[0086] ;

[0087] Calculate the The probability of disturbance of the future mains amplitude at a time point , No. The probability of future mains phase disturbance at a time point , and The probability of future load-side disturbance at a time point ;

[0088] in, It is based on the UPS and mains output data set. The time series factor set at each time point indicates whether the fluctuation trend of UPS output is affected by the mains disturbance within a certain time window (such as 5 minutes), and reflects the possibility of short-term disturbances in the future. Setting basis: Comparison of UPS and mains data: By sampling the amplitude and phase data of UPS output, as well as the amplitude and phase data of mains input in the corresponding time period, compare their fluctuation trends. Fluctuation range and trend evaluation: Determine the fluctuation range of UPS output and mains input in a short period of time (such as the maximum change in amplitude fluctuation, phase drift rate, etc.), and determine the time series factor through the root mean square (RMS) change rate or fluctuation standard deviation in the time window. When the fluctuation of UPS output is highly correlated with the fluctuation of mains input, it means that the UPS is greatly disturbed by the mains in the current period. If the UPS output fluctuation is relatively stable, that is, the mains disturbance is not significantly transmitted to the UPS output, then For example, by collecting the real-time voltage and phase data of the UPS and the mains, the root mean square value (RMS) within a short time window (such as 5 minutes) is calculated to quantify the fluctuation range. For example, the RMS output of the UPS is , the RMS of the mains input is , and then use the Pearson correlation coefficient formula to calculate the correlation between the two , for example, the calculation result is , then according to the preset range (highly relevant: , moderately correlated: , low correlation: ) is highly correlated, indicating that UPS fluctuations are significantly affected by mains disturbances. Calculate the time series factor and get ; If the RMS of the UPS is small, such as , the correlation coefficient is , it is judged to be low correlation, indicating that the UPS output fluctuations are relatively independent, and the time series factor is By clarifying the disturbance range and correlation degree between UPS and AC power, it provides a basis for accurate assessment of the probability of future short-term disturbances of UPS.

[0089] Assume that the perturbation weight data is as follows:

[0090] Mains amplitude disturbance weight , ,

[0091] Mains phase disturbance weight , ,

[0092] Load end disturbance weight , ,

[0093] Assume that the time series factor is calculated based on short-term fluctuations as follows:

[0094] , .

[0095] Future short-term probability of mains amplitude disturbance:

[0096] ,

[0097] .

[0098] Future short-term probability of mains phase disturbance:

[0099] ,

[0100] .

[0101] Future short-term probability of load-side disturbance:

[0102] ,

[0103] .

[0104] Calculation results:

[0105] Disturbance Type Event 1 Event 2 Probability of mains amplitude disturbance 0.62 0.18 Mains phase disturbance probability 0.62 0.18 Load end disturbance probability 0.58 0.21

[0106] See also Figure 5 , the specific steps for obtaining the voltage feedforward instruction set are:

[0107] According to different future disturbance probability sets, the mains power fluctuation range in the future specified period is derived to generate the mains power fluctuation information in the future period;

[0108] First, the probability distribution of each disturbance event is processed. Assuming that the next five-minute time window is divided into 300 sampling points (taking one sampling per second as an example), the probability of mains amplitude disturbance (event 1 is 0.62, event 2 is 0.18), mains phase disturbance probability (event 1 is 0.62, event 2 is 0.18) and load-end disturbance probability (event 1 is 0.58, event 2 is 0.21) are distributed and mapped respectively, and the disturbance contribution at each time point is calculated. For example, the disturbance probability of event 1, 0.62, is evenly mapped to the five-minute time axis, and the disturbance contribution per second is , for event 2, its disturbance contribution is . Similarly, the mapping of the mains amplitude, phase and load-side disturbance probability is processed respectively. Secondly, for each time point, two disturbance events of the same type are superimposed. For example, at a certain time point t, the comprehensive probability of the mains amplitude disturbance is , the mains phase disturbance and load-end disturbance are calculated in the same way. By traversing all 300 time points, the comprehensive disturbance probability distribution of each disturbance type on the time axis for the next five minutes is obtained. Then, according to the distribution of the disturbance probability, the fluctuation range for the next five minutes is defined. For example, for the mains amplitude disturbance, the judgment standard for the disturbance intensity is set as: the mains amplitude disturbance probability When the disturbance is within the “significant disturbance interval”, it belongs to the “normal disturbance interval”; similarly, corresponding disturbance intensity thresholds are set for the mains phase disturbance and the load-end disturbance, such as the mains phase disturbance probability and load-side disturbance probability It belongs to the "significant disturbance interval" when the disturbance type is in the "significant disturbance interval". According to this standard, the significance of the disturbance type on the time axis is judged point by point, forming a complete distribution of high disturbance and low disturbance intervals in the next five minutes. Through the above derivation process, the fluctuation interval distribution of the mains amplitude disturbance, mains phase disturbance and load-end disturbance in the next five minutes can be obtained respectively, and the time distribution characteristics of each disturbance type are quantified. Combined with the comprehensive probability of the disturbance type, the overall interval description of the mains fluctuation in the next five minutes is finally formed.

[0109] According to the future mains power fluctuation interval derived from the future mains power fluctuation information, the amplitude or phase compensation that needs to be executed in advance is determined, the UPS feedforward adjustment value is mapped, and a voltage feedforward instruction set is generated;

[0110] According to the derived mains fluctuation range, the amplitude or phase compensation that needs to be performed in advance is determined for each disturbance type (mains amplitude disturbance, mains phase disturbance and load-end disturbance), mapped to the UPS feedforward adjustment value and generated a voltage feedforward instruction set. First, for mains amplitude disturbance, according to the classification of significant disturbance and ordinary disturbance in the fluctuation range, in the significant disturbance range, such as at a certain time point The probability of comprehensive amplitude disturbance , then the UPS output voltage needs to be compensated for amplitude, by calculating the amplitude deviation ,in: It is the voltage of the AC input, in volts (V), and is measured in real time by the voltage sampling device at the AC input end. It is the voltage at the UPS output end, in volts (V), measured in real time by the UPS output sampling device. , taking it as the amplitude adjustment target, mapping the UPS adjustment value, and setting it as The compensation instruction is sent, and the compensation operation is performed one by one for all time points in the significant disturbance interval within the next five minutes. For the mains phase disturbance, according to the derived fluctuation interval, in the significant disturbance interval, such as at a certain time point The comprehensive phase perturbation probability , it is necessary to dynamically compensate the phase of the UPS output by calculating the phase deviation ,in: It is the phase angle of the AC input, measured in degrees (°). The fundamental phase of the AC input voltage waveform is obtained through a phase measurement device. is the phase angle of the UPS output, in degrees (°). The fundamental phase of the UPS output voltage waveform is measured by the phase measurement device at the UPS output end. Assume that at a certain time point in a significant disturbance interval , then the phase compensation value of the mapped UPS is set to , execute phase compensation instructions point by point in the significant disturbance interval in the next five minutes to ensure that the output phase of the UPS is synchronized with the mains. For load-side disturbances, combined with the fluctuation interval, such as at a certain time point The comprehensive load-side disturbance probability , then the UPS output current amplitude needs to be adjusted by calculating the load end current deviation ,in: It is the current at the load end, measured in amperes (A), by the current sampling device at the load end. is the current output by the UPS in amperes (A), measured by the current sampling device at the UPS output end. , mapping the compensation value of UPS output current, set to , and generate corresponding current compensation instructions, which are implemented point by point in the significant disturbance interval. Finally, based on the compensation results of each disturbance type derived from the mains fluctuation interval, the above amplitude compensation instructions are , Phase compensation instruction and current compensation instructions Mapped to the UPS feedforward adjustment value, generate a complete voltage feedforward instruction set, and load it point by point in the UPS system to ensure that the UPS can perform synchronous dynamic compensation operations for the mains disturbance within the next five-minute time window.

[0111] See also Figure 6 , the specific steps for obtaining the phasor waveform set are:

[0112] Apply the UPS feedforward adjustment value corresponding to the voltage feedforward instruction set to the UPS output, obtain the UPS output voltage waveform and the mains voltage waveform and perform multi-frequency sampling, convert the sample sequence formed by the multi-frequency sampling to the d-axis and q-axis components of the same coordinate system through Park transformation, for the mains voltage waveform, obtain the phase of the mains voltage fundamental wave and set it as the reference phase, the d-axis is aligned with the mains voltage fundamental wave phase, and the q-axis is orthogonal to the mains voltage fundamental wave phase, for the UPS output voltage waveform, its reference phase is at the same frequency as the mains voltage fundamental wave phase, the d-axis represents the part of the UPS output voltage waveform that is in phase with the mains voltage fundamental wave phase, and the q-axis represents the part of the UPS output voltage waveform that is orthogonal to the mains voltage fundamental wave phase, and generate component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinate;

[0113] Apply the corresponding UPS feedforward adjustment value in the voltage feedforward instruction set to the UPS output, obtain the UPS output voltage waveform and the mains voltage waveform and perform multi-frequency sampling, use a high-precision data acquisition card (such as NIPXIe-6124) to perform synchronous sampling at a sampling rate of 10kHz, record the instantaneous waveform data of the UPS output voltage and the instantaneous waveform data of the mains input voltage, store these data in MATLAB for data processing, call the resample function in MATLAB to resample the sampled data to ensure timing alignment, and use the fft function to analyze the frequency components of the waveform, calculate the amplitude distribution of the fundamental wave and harmonics, obtain the phase information of the UPS output voltage and the mains input voltage through the Hilbert transform, and extract the mains fundamental wave phase , which is used for subsequent transformation of the basis. To perform Park transformation in MATLAB, first construct the dq axis transformation matrix: ,in, It is the component of the UPS output voltage waveform on the d-axis, indicating the part of the UPS output voltage waveform that is in phase with the fundamental wave of the AC voltage. It is the component of the UPS output voltage waveform on the q axis, indicating the part of the UPS output voltage waveform that is orthogonal to the phase of the AC voltage fundamental wave. It is calculated by Park transformation. and Transform to the dq axis coordinate system. Use the dqTransform custom function in MATLAB to calculate the dq components. It is the fundamental phase angle of the mains voltage, which is used as the reference for dq transformation. The phase information of the mains input voltage waveform is extracted through Hilbert transformation. The instantaneous phase angle is extracted using the Hilbert function in MATLAB. It is the α-axis component after Clarke transformation, corresponding to the projection of the UPS output voltage in the stationary coordinate system. It is the β-axis component after Clarke transformation, corresponding to the projection of the UPS output voltage in the stationary coordinate system. It is calculated by Clarke transformation, which converts the three-phase voltage into the α-β stationary coordinate system. ClarkeTransform is used in MATLAB to calculate the α-β axis component. Transformation matrix It is used to rotate the voltage component of the α-β axis coordinate system to the dq axis coordinate system, with the AC fundamental phase as the transformation reference, the d axis is aligned with the AC fundamental phase, and the q axis is orthogonal to the AC fundamental phase. The transformation matrix is ​​calculated through MATLAB, and the UPS output voltage waveform and the AC voltage waveform are transformed by dq axes respectively. Finally, the dq axis components of the UPS output voltage waveform and the AC voltage waveform are calculated in MATLAB, and the dq axis waveform distribution is plotted to provide benchmark data for subsequent harmonic component analysis.

[0114] Based on the component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinates, the main harmonic amplitudes and phases in the UPS output voltage waveform and the mains voltage waveform are marked, and the harmonic amplitudes of the observable components in the UPS output voltage waveform and the mains voltage waveform other than the main harmonic amplitudes and phases are distinguished to generate a phasor waveform set;

[0115] Mark the 3rd and 5th components in the UPS output voltage waveform and the mains voltage waveform as the main harmonic amplitude and phase, distinguish the harmonic amplitude of other observable components, generate a phasor waveform set, calculate the frequency spectrum data of the UPS output voltage waveform and the mains voltage waveform through MATLAB fft, set the frequency resolution to 1 Hz in MATLAB, calculate the amplitude spectrum and phase spectrum after FFT transformation, extract the harmonic component with the largest amplitude through findpeaks function, and screen the 3rd harmonic (3 times the fundamental frequency) and the 5th harmonic (5 times the fundamental frequency), calculate the amplitude ratio and phase difference between the UPS output and the mains input for the 3rd harmonic and the 5th harmonic, respectively, use the angle function to extract the phase information of the corresponding harmonic and store it in the phasor data structure. For other observable harmonic components, set the harmonic amplitude threshold (such as greater than 5% of the fundamental amplitude), use findpeaks to screen the harmonic components that exceed the threshold, and calculate their amplitude ratio and phase difference relative to the fundamental wave. Store all harmonic data in the MATLAB structure variable harmonicsStruct, use the bar function to draw the harmonic amplitude distribution diagram of the UPS output voltage waveform and the mains voltage waveform, and use the polarplot function to draw the phasor diagram of the UPS output voltage waveform and the mains voltage waveform.

[0116] See also Figure 7 , the steps for obtaining the output voltage adjustment result are as follows:

[0117] Compare the phasor deviations of the UPS output and the mains voltage on each main harmonic component in the phasor waveform set to generate deviation information of the UPS output on each harmonic component;

[0118] After obtaining the phasor waveform set of UPS output and mains input, the phasor deviation of UPS output and mains voltage on each main harmonic component is compared, and the fundamental wave, third harmonic and fifth harmonic are selected as the main comparison components. FFT calculation is performed by MATLAB to extract the amplitude and phase information of UPS output and mains input, and the comparison is performed for different harmonic components. For example, in the case of the third harmonic, the third harmonic phasor information of UPS output is extracted, including the amplitude and phase angle, and the phasor information of the mains input at the same frequency is extracted at the same time. The third harmonic amplitude of UPS output is recorded as 2.3V, the third harmonic amplitude of mains input is 2.1V, the phase angle of UPS output is 45°, and the phase angle of mains input is 50°. By comparing the amplitude, it is found that the harmonic amplitude of UPS output is slightly higher than that of mains input. The third harmonic amplitude deviation of UPS output is calculated to be 0.2V, and the phase deviation is -5°, that is, the UPS output has a 5° phase lag relative to the mains input on the third harmonic. Similarly, in the case of the fifth harmonic, the amplitude of the UPS output is 1.8V, the amplitude of the AC input is 2.0V, the phase angle of the UPS output is 60°, and the phase angle of the AC input is 58°. By comparing the phases of the UPS output and the AC input, the amplitude of the fifth harmonic of the UPS output is lower than that of the AC input, the amplitude deviation is -0.2V, and the phase deviation is +2°, that is, the fifth harmonic of the UPS output has a 2° phase lead relative to the AC input. For the fundamental wave part, by comparing the amplitude and phase of the UPS output and the AC input, the fundamental wave amplitude of the UPS output is recorded as 220V, the fundamental wave amplitude of the AC input is 218V, the phase angle of the UPS output is 0°, and the phase angle of the AC input is 1°. The fundamental wave amplitude deviation of the UPS output is calculated to be 2V, and the phase deviation is -1°, that is, the fundamental wave of the UPS output has a 1° phase lag relative to the AC input. Through the above comparison process, the phasor deviation of the UPS output on different harmonic components is analyzed in detail, the amplitude difference and phase difference data between the UPS output and the mains input are obtained, and the deviation information of the UPS output on each harmonic component is recorded.

[0119] The deviation information of UPS output on each harmonic component is added or merged into the amplitude and phase of UPS output as a correction amount to generate an output voltage adjustment result;

[0120] According to the obtained amplitude and phase deviation of each main harmonic component between UPS output and mains input, the adjustment strategy is defined in MATLAB to set the correction method of the fundamental wave, third harmonic and fifth harmonic of UPS output. For example, in the fundamental wave part, since the fundamental wave amplitude of UPS output is 2V higher than the mains input and the phase lags 1°, it is necessary to adjust the fundamental wave amplitude of UPS output to reduce it by 2V and adjust the phase to advance by 1° to ensure synchronization with the mains input. In the specific implementation process, the correction amount of UPS output is calculated using CorrectionFactor in MATLAB and superimposed on the amplitude and phase of UPS output. For the third harmonic part, the amplitude of UPS output is 0.2V higher than the mains input and the phase lags 5°. Therefore, it is necessary to reduce the amplitude of the third harmonic of UPS output by 0.2V and adjust the phase to advance by 5° to keep the third harmonic of UPS output consistent with the mains input. The corrected data of the third harmonic of UPS is calculated in MATLAB, stored in the UPS_Corrected_Harmonic_Struct variable, and inversely transformed by ifft to obtain the adjusted UPS output signal. In the fifth harmonic part, since the amplitude of UPS output is 0.2V lower than the mains input and the phase is 2° ahead, it is necessary to adjust the amplitude of the fifth harmonic output of UPS to increase it by 0.2V and adjust the phase lag by 2° to ensure that the fifth harmonic output of UPS matches the mains input. The adjusted fifth harmonic data is calculated by MATLAB, and the adjustment result is stored in the corrected data set of UPS output voltage waveform. Finally, the corrected signal of UPS output is synthesized in MATLAB, and the time domain signal of UPS output is regenerated by ifft inverse transformation. The phasor distribution before and after the UPS output adjustment is displayed by plot and polarplot to ensure that the amplitude and phase adjustment of UPS output reach the target and the UPS output voltage adjustment result meets the phasor characteristics of the mains input.

[0121] See also Figure 8 , the specific steps for obtaining the adaptive synchronization result between the output voltage and the mains are:

[0122] Compare the amplitude and phase of the corrected UPS output on each frequency component in the output voltage adjustment result with the amplitude and phase of the mains voltage on the same frequency component one by one to generate a phase comparison result of the mains input;

[0123] First, the frequency analysis of the corrected UPS output is performed through the fft (fast Fourier transform) function in MATLAB or Python to obtain the amplitude and phase information of the main frequency components such as the fundamental wave, third harmonic, and fifth harmonic, and compare them with the corresponding components of the mains input. Since the UPS output has been adjusted, the amplitude and phase of the frequency components may have changed, so it is necessary to re-extract the latest phasor information of the UPS output instead of directly using the deviation information obtained by the previous calculation. After obtaining the phasor data of the UPS output and the mains input at the same frequency point, the angle function in MATLAB is used to extract the phase information of the UPS output and the mains input, and the abs function is used to calculate the amplitude of each frequency component. For the fundamental wave part, the amplitude of the UPS output and the mains input is extracted, and the amplitude deviation is calculated. At the same time, the phase deviation of the UPS output and the mains input is calculated to determine whether the UPS output is consistent with the mains in terms of the fundamental wave component. For the harmonic components, the same method is used to obtain the harmonic amplitude and phase information of the UPS output and the mains input one by one, and the corresponding amplitude and phase deviation are calculated. In order to ensure the accuracy of data analysis, a certain sampling accuracy is set in MATLAB to ensure that the spectrum data of UPS output and mains input are aligned on the same time axis, and interpolation is performed using interp1 to reduce data deviation. Finally, the phase comparison of UPS output and mains input is visualized through the plot function in MATLAB, and the phase difference between each frequency component of UPS and mains input is displayed using polarplot, providing basic data for subsequent synchronization judgment.

[0124] According to the phase comparison result of the mains input, the synchronization state between the UPS output voltage and the mains voltage is confirmed. If the synchronization requirements are met, the UPS output is determined to be adaptively synchronized with the mains. When the UPS confirms the synchronization state, the UPS can be safely switched to the bypass mode to generate the output voltage and the mains adaptive synchronization result;

[0125] First, set the synchronization judgment threshold, and set the corresponding amplitude and phase synchronization standards for different frequency components. For example, the fundamental wave part requires the amplitude error to be less than ±2V, the phase error to be less than ±2°, the amplitude error of the third harmonic and the fifth harmonic to be less than ±0.5V, and the phase error to be less than ±3°. If all the frequency components of the UPS output meet the set standards, the UPS output is determined to be adaptively synchronized with the mains. In MATLAB, by judging the synchronization status of the UPS output and the mains input, set the SyncStatus variable to store the synchronization status of each frequency component. If the errors of all the frequency components of the UPS output are within the allowable range, set SyncStatus=1, otherwise set SyncStatus=0, and trigger the subsequent adjustment process. When the UPS confirms the synchronization status, the UPS can safely switch to bypass mode to reduce the power loss of the UPS inverter and improve the overall power supply efficiency. If the UPS output does not meet the synchronization conditions, it is necessary to further adjust the amplitude or phase of the UPS to gradually approach the AC input to ensure that the synchronization standards are met, and finally complete the determination of the UPS adaptive synchronization state and the generation of output results. Finally, a bar chart is used to visualize the synchronization error between the UPS output and the AC input.

[0126] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An output voltage and mains power adaptive synchronization system, characterized in that: The system comprises: The disturbance weight setting module obtains the mains amplitude and phase data and load-end disturbance information in the substation system, analyzes the corresponding adjacent disturbance phenomena and sets the disturbance weights to generate a disturbance weight set; The feedforward estimation execution module calculates the future disturbance probability according to the disturbance weight set, derives the mains power fluctuation range in the future specified period, determines the amplitude or phase compensation that needs to be executed in advance according to the mains power fluctuation range, and generates a voltage feedforward instruction set; The phasor sampling conversion module applies the voltage feedforward instruction set to the UPS output terminal, obtains the UPS output voltage waveform and the mains voltage waveform and performs multi-frequency sampling, converts the sample sequence formed by the multi-frequency sampling to the same coordinate system through Park transformation, marks the main harmonic amplitude and phase, and generates a phasor waveform set; The harmonic difference adjustment module compares the phasor deviation of the UPS output voltage waveform and the mains voltage waveform in the phasor waveform set on each main harmonic component, uses the phasor deviation as a real-time correction amount to further correct the UPS output voltage, and generates an output voltage adjustment result; The adaptive synchronization generation module confirms the synchronization state between the UPS output voltage and the mains voltage in the output voltage adjustment result. If the synchronization requirement is met, it determines that the UPS output is adaptively synchronized with the mains, and generates an output voltage and mains adaptive synchronization result.

2. The output voltage and mains power adaptive synchronization system according to claim 1, characterized in that: The steps of analyzing the corresponding adjacent disturbance phenomena are specifically as follows: Obtain the mains amplitude and phase data and load-end disturbance information in the substation system, wherein the mains amplitude and phase data are collected by a voltage sampling device installed at the AC incoming line loop or the AC bus, and the load-end disturbance information is obtained by statistics of the operating data on the load side, generating a mains voltage change and load-end disturbance data set; Based on the mains voltage change and load-end disturbance data set, adjacent disturbance phenomena corresponding to mains amplitude and phase changes, and adjacent disturbance phenomena corresponding to load-end disturbances are analyzed, and the correlation between different adjacent disturbance phenomena is calculated using the Pearson correlation coefficient to generate adjacent disturbance phenomenon analysis results.

3. The output voltage and mains power adaptive synchronization system according to claim 2, characterized in that: The steps for obtaining the disturbance weight set are specifically as follows: Based on the analysis results of the adjacent disturbance phenomenon, the formula is adopted: ， ， ； In the analysis results of adjacent disturbance phenomena, the current The adjacent disturbance weight of a mains amplitude disturbance event among all mains amplitude disturbance events , the current The adjacent disturbance weight of a mains phase disturbance event among all mains phase disturbance events , the current The adjacent disturbance weight of a load-side current disturbance event among all load-side current disturbance events , obtain adjacent disturbance weights, integrate all the adjacent disturbance weights to generate a disturbance weight set; in, It is the current one in the adjacent disturbance phenomenon analysis results. The voltage amplitude change of a mains amplitude disturbance event, It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all mains amplitude disturbance events. The voltage amplitude change of a mains amplitude disturbance event, It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of the mains amplitude disturbance event, It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all mains amplitude disturbance events. The correlation coefficient of each mains amplitude disturbance event, It is the current one in the adjacent disturbance phenomenon analysis results. The phase change of a mains phase disturbance event, It is the first phase disturbance event corresponding to the adjacent disturbance phenomenon analysis result when traversing all the mains phase disturbance events. Phase change of a mains phase disturbance event, It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of the mains phase disturbance events is It is the first phase disturbance event corresponding to the adjacent disturbance phenomenon analysis result when traversing all the mains phase disturbance events. The correlation coefficient of the mains phase disturbance events is It is the current one in the adjacent disturbance phenomenon analysis results. The current change of a load-side current disturbance event, It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all load-side current disturbance events. The current change of a load-side current disturbance event, It is the current one in the adjacent disturbance phenomenon analysis results. The correlation coefficient of the load-side current disturbance events, It is the first value corresponding to the adjacent disturbance phenomenon analysis result when traversing all load-side current disturbance events. The correlation coefficient of the load-side current disturbance events, is the total number of all mains amplitude disturbance events or mains phase disturbance events in the adjacent disturbance phenomenon analysis results, is the total number of load-side current disturbance events in the adjacent disturbance phenomenon analysis results, To iterate over all or different disturbance events.

4. The output voltage and mains power adaptive synchronization system according to claim 3, characterized in that: The steps of calculating the future disturbance probability are specifically as follows: Obtain UPS output amplitude and phase data of AC and DC power supplies, as well as AC power amplitude and phase change inputs, to generate UPS and AC power output data sets; Based on the UPS and mains output data set and the disturbance weight set, the formula is used: ， ， ； Calculate the The probability of disturbance of the future mains amplitude at a time point , No. The probability of future mains phase disturbance at a time point , and The probability of future load-side disturbance at a time point , generating different sets of future perturbation probabilities; in, It is based on the UPS and mains output data set. A time series factor set at each time point.

5. The output voltage and mains power adaptive synchronization system according to claim 4, characterized in that: The steps for acquiring the voltage feedforward instruction set are specifically as follows: According to the different future disturbance probability sets, deriving the mains power fluctuation interval in a future specified time period, and generating the mains power fluctuation information in the future time period; The amplitude or phase compensation that needs to be performed in advance is determined according to the future mains power fluctuation interval derived from the mains power fluctuation information in the future period, and the UPS feedforward adjustment value is mapped to generate a voltage feedforward instruction set.

6. The output voltage and mains power adaptive synchronization system according to claim 1, characterized in that: The steps of obtaining the phasor waveform set are specifically as follows: Apply the UPS feedforward adjustment value corresponding to the voltage feedforward instruction set to the UPS output, obtain the UPS output voltage waveform and the mains voltage waveform and perform multi-frequency sampling, convert the sample sequence formed by the multi-frequency sampling to the d-axis and q-axis components of the same coordinate system through Park transformation, for the mains voltage waveform, obtain the phase of the mains voltage fundamental wave and set it as the reference phase, the d-axis is aligned with the mains voltage fundamental wave phase, and the q-axis is orthogonal to the mains voltage fundamental wave phase, for the UPS output voltage waveform, its reference phase is at the same frequency as the mains voltage fundamental wave phase, the d-axis represents the part of the UPS output voltage waveform that is in phase with the mains voltage fundamental wave phase, and the q-axis represents the part of the UPS output voltage waveform that is orthogonal to the mains voltage fundamental wave phase, and generate component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinate; Based on the component distribution information of the UPS output voltage waveform and the mains voltage waveform under the same reference coordinates, the main harmonic amplitudes and phases in the UPS output voltage waveform and the mains voltage waveform are marked, and the harmonic amplitudes of the observable components in the UPS output voltage waveform and the mains voltage waveform other than the main harmonic amplitudes and phases are distinguished to generate a phasor waveform set.

7. The output voltage and mains power adaptive synchronization system according to claim 1, characterized in that: The steps of obtaining the output voltage adjustment result are specifically as follows: Comparing the phasor deviations of the UPS output and the mains voltage in each main harmonic component in the phasor waveform set, and generating deviation information of the UPS output in each harmonic component; The deviation information of the UPS output on each harmonic component is superimposed or merged into the amplitude and phase of the UPS output as a correction amount to generate an output voltage adjustment result.

8. The output voltage and mains power adaptive synchronization system according to claim 1, characterized in that: The steps for obtaining the result of the adaptive synchronization between the output voltage and the mains are as follows: Compare the amplitude and phase of the corrected UPS output on each frequency component in the output voltage adjustment result with the amplitude and phase of the mains voltage on the same frequency component one by one to generate a phase comparison result of the mains input; According to the phasor comparison result of the AC power input, the synchronization state between the UPS output voltage and the AC power voltage is confirmed. If the synchronization requirements are met, the UPS output is determined to be adaptively synchronized with the AC power. When the UPS confirms the synchronization state, the UPS can be safely switched to the bypass mode to generate an output voltage and AC power adaptive synchronization result.

Images