Distributed power supply grid-connected control method and system, medium and storage device

Abstract

The invention belongs to the technical field of distributed power supply grid-connected control, and particularly relates to a distributed power supply grid-connected control method and system, a medium and storage equipment, and the method comprises the steps: obtaining a multi-dimensional power grid state data set; calculating a load change trend of the distributed power supply based on the obtained multi-dimensional power grid state data set; adjusting operation parameters of the power grid according to the obtained load change trend, and generating an operation parameter adjustment record; calling the generated operation parameter adjustment record, detecting the voltage drop amplitude of the grid-connected point of the distributed power supply, and generating a voltage compensation gradient value; based on the generated voltage compensation gradient value, detecting and analyzing phase sequence characteristics of a distributed power supply grid-connected point in real time, adjusting harmonic impedance, and generating a harmonic suppression parameter; and calling the generated harmonic suppression parameter, monitoring the load fluctuation of the distributed power supply grid-connected point in real time, obtaining a load synchronous adjustment parameter, and completing the grid-connected control of the distributed power supply.

Description

Technical Field

[0001] The present invention belongs to the technical field of distributed power grid connection control, and particularly relates to a distributed power grid connection control method, system, medium and storage device. Background Art

[0002] The statements in this part merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] The field of power automation technology includes multiple aspects such as the automatic control, monitoring, dispatching and optimization of power systems, aiming to achieve the efficient, safe and stable operation of power systems through automation technology, including the remote monitoring, condition detection, fault diagnosis, automatic dispatching and power grid management of power equipment, focusing on improving the reliability, flexibility and economy of power systems while ensuring power supply, covering various technologies such as the protection and control of power systems, smart distribution grids, power load forecasting, power grid dispatching and optimization, and distributed power access, and enhancing the adaptive ability and emergency response ability of power systems.

[0004] Distributed power grid connection control is a control technology specifically for the connection of distributed power sources to the power grid, involving power regulation and synchronization control required during the process of distributed power sources accessing the power grid, aiming to solve various problems such as voltage fluctuations and current instability caused by distributed power sources during grid connection. By real-time monitoring and adjusting the output power of distributed power sources, it ensures the coordinated operation of the power grid and distributed power sources, including power balance control, voltage and frequency regulation, and grid connection operations implemented through an automatic control system, ensuring that distributed power sources remain synchronized with the power grid during the grid connection process and avoiding adverse effects.

[0005] Traditional power grid connection control methods have certain limitations in distributed power grid connection control. They have insufficient real-time and comprehensive processing of power grid operation data, resulting in the inability to accurately predict and respond to load changes. They rely on fixed operation parameter adjustment strategies, lack the ability to dynamically adjust the voltage transient drop amplitude in stages, causing voltage fluctuations and current instability problems. Their ability to suppress harmonic interference is limited, and they fail to fully analyze the phase sequence relationship between the output waveform of distributed power sources and the power grid waveform, resulting in poor harmonic impedance regulation effect and affecting power quality. Their ability to monitor and predict load fluctuations is weak, and it is difficult to adjust the output power and frequency regulation parameters of distributed power sources in real time, resulting in an unsatisfactory synchronous operation effect between the power grid and distributed power sources. When dealing with complex power grid environments and large-scale access of distributed power sources, traditional technologies have problems such as low operation efficiency, insufficient stability and weak emergency response ability, affecting the overall performance of power systems. Summary of the Invention

[0006] To solve the above problems, the present invention proposes a distributed power grid connection control method, system, medium and storage device. By obtaining real-time power grid operation data, it comprehensively reflects the real-time state of the power grid. Using the detection of the transient voltage drop amplitude at the connection point of the distributed power source, it realizes phased adjustment of the output power, analyzes the phase sequence relationship between the output waveform of the distributed power source and the power grid waveform, adjusts the harmonic impedance, monitors the load fluctuation in real time and predicts the load trend, and adjusts the output power and frequency adjustment parameters to ensure the synchronous operation of the distributed power source and the power grid, and enhances the adaptive ability and emergency response ability.

[0007] According to some embodiments, the first solution of the present invention provides a distributed power grid connection control method, adopting the following technical solution:

[0008] A distributed power grid connection control method includes:

[0009] Obtain a multi-dimensional power grid state data set;

[0010] Calculate the load change trend of the distributed power source based on the obtained multi-dimensional power grid state data set;

[0011] Adjust the operation parameters of the power grid according to the obtained load change trend, and generate an operation parameter adjustment record;

[0012] Call the generated operation parameter adjustment record, detect the voltage drop amplitude at the connection point of the distributed power source, and generate a voltage compensation gradient value;

[0013] Based on the generated voltage compensation gradient value, detect and analyze the phase sequence characteristics at the connection point of the distributed power source in real time, adjust the harmonic impedance, and generate harmonic suppression parameters;

[0014] Call the generated harmonic suppression parameters, monitor the load fluctuation at the connection point of the distributed power source in real time, obtain load synchronization adjustment parameters, and complete the grid connection control of the distributed power source.

[0015] As a further technical limitation, in the process of obtaining the multi-dimensional power grid state data set, obtain real-time power grid operation data including instantaneous voltage, frequency fluctuation, load change rate and power factor, perform time series aggregation on the obtained real-time power grid operation data, calculate the statistical characteristics in each time interval, obtain a time series aggregation data set, align the aggregation data in the obtained time series aggregation data set according to the time dimension and perform multi-dimensional combination, calculate the power grid operation stability, and obtain the multi-dimensional power grid state data set.

[0016] As a further technical limitation, the output power of the distributed power source and the grid load demand data are extracted from the obtained multi-dimensional power grid state data set, and the change trends of the power output and the load demand in multiple time periods are calculated, that is, the load change trend of the distributed power source is obtained; the fluctuation range of the grid load is evaluated according to the obtained load change trend to obtain load fluctuation data; the operation parameters of the power grid are adjusted in combination with the obtained load fluctuation data, and an operation parameter adjustment record is obtained.

[0017] As a further technical limitation, the generated operation parameter adjustment record is called to obtain the grid load demand change data, the voltage sag amplitude is detected according to the obtained data, real-time voltage sag data is generated, and the voltage transient sag amplitude is classified, and the adjustment requirements of the power output for various change amplitudes are analyzed to generate a sag amplitude classification result; according to the sag amplitude classification result, the output power of the distributed power source is adjusted in stages, the power change of the power source is calculated, and a voltage compensation gradient value is generated.

[0018] As a further technical limitation, the generated voltage compensation gradient value is called to monitor the phase sequence characteristics of the connection point of the distributed power source, analyze the phase sequence relationship between the power grid waveform and the power source output waveform, identify the phase sequence difference, generate phase sequence relationship characteristic data, detect the harmonic influence between the distributed power source output waveform and the power grid waveform, calculate the harmonic waveform parameters, evaluate the power grid harmonic interference level, generate a harmonic influence evaluation value, and optimize the harmonic matching degree between the power source output waveform and the power grid waveform by adjusting the harmonic impedance parameters of the power source to generate harmonic suppression parameters.

[0019] As a further technical limitation, the generated harmonic suppression parameters are called to monitor the load fluctuation at the connection point of the distributed power source, detect the amplitude and frequency of the load change, calculate the load change rate in each time period, obtain the load change data, predict the change trend of the load data, analyze the influence of the load trend on the power source output, generate a prediction value calculation result, adjust the output power and frequency regulation parameters of the distributed power source, optimize the response of the power source to the load change, generate load synchronization regulation parameters, and perform grid connection control of the distributed power source in combination with the generated load synchronization regulation parameters.

[0020] According to some embodiments, the second solution of the present invention provides a distributed power source grid connection control system, which adopts the following technical solutions:

[0021] A distributed power source grid connection control system includes:

[0022] An acquisition module configured to acquire a multi-dimensional power grid state data set;

[0023] A calculation module configured to calculate the load change trend of the distributed power source based on the acquired multi-dimensional power grid state data set;

[0024] A generation module, which is configured to adjust the operating parameters of the power grid according to the obtained load change trend, generate an operating parameter adjustment record; call the generated operating parameter adjustment record, detect the voltage sag amplitude at the connection point of the distributed power source, and generate a voltage compensation gradient value; based on the generated voltage compensation gradient value, detect and analyze the phase sequence characteristics at the connection point of the distributed power source in real time, adjust the harmonic impedance, and generate harmonic suppression parameters;

[0025] A control module, which is configured to call the generated harmonic suppression parameters, monitor the load fluctuations at the connection point of the distributed power source in real time, obtain load synchronous adjustment parameters, and complete the grid connection control of the distributed power source.

[0026] According to some embodiments, the third solution of the present invention provides a computer-readable storage medium, adopting the following technical solution:

[0027] A computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, it implements the steps in a distributed power source grid connection control method as described in the first solution of the present invention.

[0028] According to some embodiments, the fourth solution of the present invention provides an electronic device, adopting the following technical solution:

[0029] An electronic device, including a memory, a processor, and a program stored on the memory and running on the processor, and when the processor executes the program, it implements the steps in a distributed power source grid connection control method as described in the first solution of the present invention.

[0030] According to some embodiments, the fifth solution of the present invention provides a computer program product, adopting the following technical solution:

[0031] A computer program product, including software code, and the program in the software code executes the steps in a distributed power source grid connection control method as described in the first solution of the present invention.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The present invention obtains the power grid operation data in real time, comprehensively reflects the real-time state of the power grid, uses the detection of the voltage transient sag amplitude at the connection point of the distributed power source to realize the phased adjustment of the output power, effectively alleviates the voltage fluctuation problem, improves the stability of the power grid, analyzes the phase sequence relationship between the output waveform of the distributed power source and the power grid waveform, adjusts the harmonic impedance, reduces the harmonic interference, monitors the load fluctuations in real time and predicts the load trend, adjusts the output power and frequency adjustment parameters, ensures the synchronous operation of the distributed power source and the power grid, and enhances the adaptive ability and emergency response ability. Description of the Drawings

[0034] The accompanying drawings forming a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments and descriptions thereof of this embodiment are used to explain this embodiment and shall not unduly limit this embodiment.

[0035] Figure 1 It is a flowchart of a distributed power grid connection control method in Embodiment 1 of the present invention;

[0036] Figure 2 It is a detailed flowchart of S1 in Embodiment 1 of the present invention;

[0037] Figure 3 It is a detailed flowchart of S2 in Embodiment 1 of the present invention;

[0038] Figure 4 It is a detailed flowchart of S3 in Embodiment 1 of the present invention;

[0039] Figure 5 It is a detailed flowchart of S4 in Embodiment 1 of the present invention;

[0040] Figure 6 It is a detailed flowchart of S5 in Embodiment 1 of the present invention;

[0041] Figure 7 It is a structural block diagram of a distributed power grid connection control system in Embodiment 2 of the present invention. Detailed implementation manners

[0042] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further descriptions of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0044] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0045] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0046] Embodiment 1

[0047] Embodiment 1 of the present invention introduces a distributed power grid connection control method.

[0048] As Figure 1 shown, a distributed power grid connection control method includes the following steps:

[0049] S1: Obtain real-time power grid operation data, including instantaneous voltage, frequency fluctuation, load change rate, and power factor, perform time-series aggregation on the data, and generate a multi-dimensional power grid state data set;

[0050] S2: Based on the multi-dimensional power grid state data set, calculate the change trends of the distributed power output power and the power grid load demand, and adjust the operation parameters of the power grid according to the difference between the load change rate and the conventional load level, and generate an operation parameter adjustment record;

[0051] S3: Call the operation parameter adjustment record, detect the voltage transient drop amplitude at the distributed power grid connection point and the change of the power grid load demand, and adjust the distributed power output power in stages according to the voltage drop amplitude to generate a voltage compensation gradient value;

[0052] S4: Based on the voltage compensation gradient value, detect the phase sequence characteristics at the distributed power grid connection point in real time, analyze the phase sequence relationship between the distributed power output waveform and the power grid waveform, and adjust the harmonic impedance to generate harmonic suppression parameters;

[0053] S5: Call the harmonic suppression parameters, monitor the load fluctuation at the distributed power grid connection point in real time, calculate the load change rate and predict the load trend, and adjust the distributed power output power and frequency regulation parameters to generate load synchronization regulation parameters.

[0054] The multi-dimensional power grid state data set in this embodiment includes instantaneous voltage record data, frequency fluctuation data, and load change rate information. The operation parameter adjustment record includes output power change trend information, power grid load demand data, and the volatility of the power grid load. The voltage compensation gradient value is specifically the voltage drop amplitude, power grid load demand information, and staged voltage compensation amplitude. The harmonic suppression parameters include harmonic impedance adjustment value, waveform adjustment frequency, and phase sequence adjustment coefficient. The load synchronization regulation parameters are specifically the power supply output power adjustment value, frequency regulation value, and load prediction value.

[0055] As Figure 2 shown, the steps of obtaining real-time power grid operation data, including instantaneous voltage, frequency fluctuation, load change rate, and power factor, and performing time-series aggregation on the data to generate a multi-dimensional power grid state data set are specifically as follows:

[0056] S101: Obtain power grid operation data, including instantaneous voltage, frequency fluctuation, load change rate, and power factor, perform timestamp marking on the data, and generate a power grid operation data set;

[0057] When obtaining power grid operation data, the instantaneous voltage, frequency fluctuation, load change rate, and power factor of the power grid are recorded through real-time sensors and monitoring systems. The data acquisition is real-time, and each data point is timestamped. The formula for instantaneous voltage is:

[0058]

[0059] where V inst is the instantaneous voltage, V max and V min are the maximum and minimum values of the voltage of the power grid at a certain moment respectively. For example, if the power grid voltage fluctuates between 200V and 220V at a certain moment, the instantaneous voltage is

[0060]

[0061] Frequency fluctuation is the monitoring of the power grid frequency change, and its calculation formula is;

[0062] Δf = |f current - f nominal |;

[0063] where Δf is the frequency fluctuation, f current is the currently measured power grid frequency, f nominal is the standard power grid frequency (50Hz). Assuming that the power grid frequency is 50.05Hz at a certain moment, the frequency fluctuation is:

[0064] Δf = |50.05Hz - 50Hz| = 0.05Hz;

[0065] The load change rate reflects the change rate of the load, and its calculation formula is:

[0066]

[0067] where L rate is the load change rate, L current is the load at the current moment, L previous is the load at the previous moment.

[0068] For example, if the current load is 100MW and the load at the previous moment is 95MW, the load change rate is:

[0069]

[0070] The calculation formula for the power factor is:

[0071]

[0072] where PF is the power factor, P active is the active power, P apparentis the apparent power.

[0073] Assume the active power is 80 MW and the apparent power is 100 MW, then the power factor is:

[0074]

[0075] S102: Invoke the power grid operation dataset, perform time series aggregation on the instantaneous voltage, frequency fluctuation, load change rate, and power factor, calculate the statistical features within each time interval, and generate a time series aggregation dataset;

[0076] When performing time series aggregation on parameters such as the instantaneous voltage, frequency fluctuation, load change rate, and power factor in the power grid operation dataset, first sort the data in chronological order and divide it into multiple time periods. Assume the time interval of the data is 1 minute, and aggregate the data in time periods such as every 5 minutes, 10 minutes, or 15 minutes. The goal of the aggregation process is to calculate a statistical value representing the power grid state within that time period by processing the values within each time period.

[0077] Assume the voltage data within a certain time period is 220V, 215V, 218V, 219V, 217V. Calculate the average voltage within this time period. The calculation formula is as follows:

[0078]

[0079] where V avg is the average voltage within this time period. V 1 , V 2 , V 3 , V 4 , V 5 are the voltage values within this time period, representing the voltages at different time points within this time period.

[0080] Substitute the data, and we get:

[0081]

[0082] Therefore, the average voltage within this time period is 218V, indicating the voltage change of the power grid within these 5 minutes.

[0083] For the frequency fluctuation, calculate the maximum value of the frequency fluctuation within each time period. Assume the frequency fluctuation data within a certain time period is 0.05Hz, 0.07Hz, 0.08Hz, 0.06Hz, 0.1Hz. Calculate the maximum change amount of the frequency fluctuation within this time period, that is, the calculation formula is:

[0084] Δf max = max(Δf 1 , Δf2 , Δf 3 , Δf 4 , Δf 5 );

[0085] Among them, Δf max is the maximum frequency fluctuation during this time period. Δf 1 , Δf 2 , Δf 3 , Δf 4 , Δf 5 is the frequency fluctuation value at each time point during this time period, representing the frequency change amount at different time points during this time period.

[0086] Substituting the data, we can get:

[0087] Δf max = max(0.05Hz, 0.07Hz, 0.08Hz, 0.06Hz, 0.1Hz) = 0.1Hz;

[0088] Therefore, the maximum frequency fluctuation during this time period is 0.1Hz.

[0089] The aggregation of the load change rate usually calculates the maximum amplitude of the load change within each period of time. For example, the load change rates within a certain period of time are 0.02, 0.05, 0.03, 0.04, 0.06. Calculate the maximum load change rate within this time period. The calculation formula is:

[0090]

[0091] Among them, L ratemax is the maximum load change rate during this time period, is the load change rate at each time point during this time period, representing the load change rate at different time points during this time period.

[0092] Substituting the data, we get

[0093]

[0094] Therefore, the maximum load change rate during this time period is 0.06.

[0095] The aggregation calculation of the power factor usually uses the average value of the power factor within the time period. For example, the power factors within a certain period of time are 0.92, 0.89, 0.93, 0.91, 0.88. Calculate the average value of the power factor within this time period. The calculation formula is:

[0096]

[0097] Among them, PF avgis the average value of the power factor during this time period. PF 1 , PF 2 , PF 3 , PF 4 , PF 5 is the power factor at each time point during this time period, representing the power factors at different time points during this time period.

[0098] Substitute the data, and we can get:

[0099]

[0100] Therefore, the average power factor during this time period is 0.906.

[0101] Through the above calculations, aggregated data for each time period is extracted from the power grid operation data, such as the average value of voltage, the maximum value of frequency fluctuation, the maximum value of load change rate, and the average value of power factor. The aggregated data provides necessary statistical features for subsequent power grid stability analysis.

[0102] S103: Based on the time series aggregated data set, by aligning multiple parameters according to the time dimension, performing multi-dimensional combination on the aggregation result, calculating the operation stability of the power grid, and generating a multi-dimensional power grid state data set;

[0103] The specific formula for calculating the operation stability of the power grid is:

[0104]

[0105] Calculate the power grid stability to obtain the stability index;

[0106] Among them, S is the power grid stability index, w z is the weighted coefficient of voltage fluctuation, X z is the maximum value of instantaneous voltage fluctuation during a certain time period, w j is the weighted coefficient of frequency fluctuation, Y j is the maximum amplitude of frequency fluctuation, w k is the weighted coefficient of load change rate, Z k is the maximum value of load change rate during a certain time period, Z is the number of aggregation segments of the power grid instantaneous voltage data, z is the index of the voltage fluctuation data item, m is the number of aggregation segments of the frequency fluctuation data, j is the index of the frequency fluctuation data item, p is the number of aggregation segments of the load change rate data, and k is the index of the load change rate data item.

[0107] Formula The detailed explanation and the derivation process of the formula calculation are as follows:

[0108] The formula is used to calculate the stability index S of the power grid, and evaluates the operating stability of the power grid through the weighted combination of instantaneous voltage fluctuations, frequency fluctuations, and load change rates;

[0109] w z is the weighted coefficient of voltage fluctuation, representing the influence weight of voltage fluctuation on the power grid stability, and reflecting the sensitivity of voltage fluctuation to the power grid stability;

[0110] X z is the maximum value of instantaneous voltage fluctuation within a certain time period, representing the most severe degree of voltage fluctuation during this time period;

[0111] w j is the weighted coefficient of frequency fluctuation, representing the influence weight of frequency fluctuation on the power grid stability;

[0112] Y j is the maximum amplitude of frequency fluctuation, representing the most severe degree of frequency fluctuation during this time period;

[0113] w k is the weighted coefficient of load change rate, representing the influence weight of load change rate on the power grid stability;

[0114] Z k is the maximum value of load change rate within a certain time period, representing the most severe degree of load change during this time period;

[0115] Assume that within the target time period, the maximum value of instantaneous voltage fluctuation of the power grid is 0.05, the maximum amplitude of frequency fluctuation is 0.1, and the maximum value of load change rate is 0.02, and the corresponding weighted coefficients are 0.4, 0.3, and 0.3 respectively;

[0116] Substitute the parameters into the formula for calculation, that is:

[0117] S = (0.4 × 0.05) + (0.3 × 0.1) + (0.3 × 0.02);

[0118] S = 0.02 + 0.03 + 0.006;

[0119] S = 0.056;

[0120] The result 0.056 indicates that the stability index of the power grid within this time period is 0.056, and the smaller the value, the better the power grid stability.

[0121] As Figure 3 shown, based on the multi-dimensional power grid state dataset, the steps to calculate the change trends of distributed power generation output power and power grid load demand, and adjust the operating parameters of the power grid according to the differences in load change rate and conventional load level, and generate the operating parameter adjustment record are specifically as follows:

[0122] S201: Extract the output power of distributed power sources and grid load demand data from the multi-dimensional power grid state dataset, calculate the change trends of power output and load demand over multiple time periods, and obtain the power-load change trend data;

[0123] Using the multi-dimensional power grid state dataset, extract the output power of distributed power sources and grid load demand data from the power grid operation data, calculate the change trends of power output and load demand over multiple time periods, obtain the power-load change trend data, and by measuring the power output P t and the grid load demand L t changes, use the following formula to calculate the change rate for each time period:

[0124]

[0125] where P t and P t+1 are the power outputs at the current moment and the next moment respectively. Assume that the power output P t is 50 MW at a certain moment, and P t+1 is 55 MW at the next moment, then the change rate of power output is:

[0126]

[0127] For the change rate of grid load demand, use the same calculation method. Assume that the load demand L t is 80 MW at a certain moment, and L t+1 is 85 MW at the next moment, then the change rate of load demand is:

[0128]

[0129] Based on the calculation results, obtain the change trend data of power output and load demand over multiple time periods to reflect the fluctuation trends of the grid load and power source power.

[0130] S202: Based on the power-load change trend data, calculate the difference between the load change rate and the conventional load level, evaluate the fluctuation range and stability of the grid load, and generate load fluctuation data;

[0131] Based on the power-load change trend data, calculate the difference between the load change rate and the conventional load level. The conventional load level is usually the average load value of historical data, which is set to 75 MW in this example. By comparing with the load demand L t at the current moment, calculate the difference, and the formula is as follows:

[0132] ΔL diff =|L t -L normal |;

[0133] Among them, L t is the load demand at the current moment, and L normal is the normal load level, assumed to be 75 MW. Assuming the current load demand L t is 85 MW, then the load difference is:

[0134] ΔL diff = |85 MW - 75 MW| = 10 MW;

[0135] According to the calculation result, if the difference between the load demand and the normal load level exceeds the set threshold, it can be considered that the load fluctuates, and load fluctuation data is generated accordingly.

[0136] S203: According to the load fluctuation data, combined with the stability requirements of the power grid, adjust various operating parameters of multiple power grids to generate an operating parameter adjustment record;

[0137] According to the load fluctuation data, combined with the stability requirements of the power grid, adjust the operating parameters of multiple power grids. First, determine whether the load change exceeds the set threshold, for example, the load change rate exceeds 10%. The adjustment operations may include adjusting the power output of the power grid. Assume the power output of the power grid is P t , if the load change rate exceeds the set threshold, the adjustment formula is as follows:

[0138] ΔP adjust = P t ×ΔL;

[0139] Among them, P t is the current power output, and ΔL is the load change rate. For example, if the current power output is 50 MW and the load change rate is 0.1, then the adjusted power output is:

[0140] ΔP adjust = 50 MW × 0.1 = 5 MW;

[0141] According to the calculation result, the power output of the power grid will be adjusted by 5 MW to ensure the stability of the power grid load, and a corresponding operating parameter adjustment record will be generated.

[0142] As Figure 4 shown, call the operating parameter adjustment record, detect the voltage transient drop amplitude at the distributed power source connection point and the change in power grid load demand, and adjust the output power of the distributed power source in stages according to the voltage drop amplitude. The specific steps for generating the voltage compensation gradient value are as follows:

[0143] S301: Call the operating parameter adjustment record, obtain the power grid load demand change data, and detect the voltage drop amplitude to generate real-time voltage drop data;

[0144] When calling the operating parameter adjustment record, first obtain the data on the change in grid load demand, detect the voltage sag amplitude, and generate real-time voltage sag data. The voltage sag amplitude refers to the degree of voltage drop in the power grid within a short period, which is usually caused by power equipment failures, system load fluctuations, or other factors. In the power grid, it is usually necessary to measure the normal voltage of the power grid and the voltage after the voltage sag, and calculate the difference to determine the voltage sag amplitude. The calculation formula for the voltage sag amplitude is as follows:

[0145]

[0146] Where, ΔV represents the voltage sag amplitude, V normal is the normal voltage value of the power grid, V drop is the voltage value after the voltage sag.

[0147] Assume that the normal voltage of the power grid is 220V and the voltage after the voltage sag is 200V, then the calculation of the voltage sag amplitude is:

[0148]

[0149] In this way, the voltage sag amplitude is 9.09%, which means that the power grid voltage has dropped by 9.09%.

[0150] S302: According to the real-time voltage sag data, classify the transient voltage sag amplitude, analyze the adjustment requirements of the power output of the power supply for various change amplitudes, and generate the classification result of the sag amplitude;

[0151] According to the real-time voltage sag data, next, it is necessary to classify the transient voltage sag amplitude and analyze the adjustment requirements of the power output of the power supply for different sag amplitudes. The amplitude of the voltage sag can be classified according to a predetermined standard. Assume that a sag amplitude less than 5% is a slight sag, between 5% and 10% is a medium sag, and greater than 10% is a severe sag. When the voltage sag amplitude of the power grid is 9.09%, according to the above classification standard, this belongs to a medium sag. Next, analyze the impact of this sag amplitude on the power output of the power supply and adjust the power of the power supply to compensate for the voltage change. The specific adjustment calculation formula is as follows:

[0152] ΔP adjust =P nominal ×ΔV category ;

[0153] Where, ΔP adjust represents the adjustment amount of the power output of the power supply, P nominal is the power output of the power supply under normal conditions, ΔV category is the classification coefficient of the sag amplitude.

[0154] Assume that the normal power output of the power supply is P nominalis 50MW, and the drop amplitude belongs to a medium drop ΔV category = 0.05, then the adjustment amount of the power supply power is calculated as follows:

[0155] ΔP adjust = 50MW × 0.05 = 2.5MW;

[0156] That is, when the voltage drop amplitude is 9.09%, the power supply needs to reduce the output power by 2.5MW.

[0157] S303: According to the classification result of the drop amplitude, adjust the output power of the distributed power supply in stages, calculate the change of the power supply power, and generate a voltage compensation gradient value;

[0158] According to the classification result of the voltage drop amplitude, the output power of the power supply will be adjusted in stages, and the change of the power supply power will be calculated. The adjustment process is divided into multiple stages. For different situations of voltage drop in each stage, the corresponding power change is calculated. Assuming that the voltage drop amplitude is a medium drop (9.09%), the power supply power needs to be adjusted according to this drop amplitude. The calculation formula for the power adjustment of the power supply is as follows:

[0159] ΔP = P current - P adjust ;

[0160] Among them, ΔP represents the change amount of the power supply power, P current is the actual output power of the current power supply, and P adjust is the power supply power adjusted according to the voltage drop amplitude.

[0161] Assume that the actual power P of the current power supply current is 50MW, and in the previous stage, it has been calculated that the power P that the power supply needs to adjust adjust = 2.5MW, then the change amount of the power supply power is:

[0162] ΔP = 50MW - 2.5MW = 47.5MW;

[0163] Therefore, the change amount of the power supply output power is -2.5MW, that is, the power supply power is reduced by 2.5MW, and a voltage compensation gradient value record is generated, indicating that the power supply needs to perform corresponding power adjustment to compensate for the impact of voltage drop.

[0164] As Figure 5 shown, based on the voltage compensation gradient value, the steps of detecting the phase sequence characteristics of the distributed power supply connection point in real time, analyzing the phase sequence relationship between the output waveform of the distributed power supply and the grid waveform, adjusting the harmonic impedance, and generating harmonic suppression parameters are specifically as follows:

[0165] S401: Invoke the voltage compensation gradient value, monitor the phase sequence characteristics of the connection point of the distributed power source, analyze the phase sequence relationship between the power grid waveform and the power source output waveform, identify the phase sequence difference, and generate phase sequence relationship characteristic data;

[0166] When invoking the voltage compensation gradient value, first monitor the phase sequence characteristics of the connection point of the distributed power source and analyze the phase sequence relationship between the power grid waveform and the power source output waveform. The phase sequence relationship refers to the relative positions between different phases in the power grid, and its correctness directly affects the stability of the power system. If the phase sequence of the power grid is inconsistent with that of the power source output, it may lead to phase disorder, and further cause damage to power equipment or power quality problems. When analyzing the phase sequence relationship between the power grid waveform and the power source output waveform, first obtain the voltage waveform data of the power grid and the power source output waveform data, and measure the voltage waveforms of each phase. Usually, the waveform data of the power grid is obtained by sensors, and the power source output waveform is monitored in real time by a power analyzer. By comparing the voltage waveforms of the three phases of the power grid with the voltage waveforms of the three phases of the power source output, check whether the waveforms of each phase appear at the maximum value or zero crossing point at the same moment, etc. If a phase sequence difference is found, the following calculation formula is used to quantify the difference:

[0167] Δθ = |θ grid - θ source |;

[0168] where, Δθ represents the phase sequence difference between the power grid and the power source, θ grid represents the power grid phase angle; θ source represents the power source phase angle. Suppose the phase angle of a certain phase of the power grid is 30°, and the phase angle of the power source output is 40°, the phase sequence difference is:

[0169] Δθ = |30° - 40°| = 10°;

[0170] At this time, the phase sequence difference is 10°. Identify the phase sequence difference between the power grid and the power source through the calculation result, and generate phase sequence relationship characteristic data.

[0171] S402: Based on the phase sequence relationship characteristic data, detect the harmonic influence between the distributed power source output waveform and the power grid waveform, calculate the harmonic waveform parameters, evaluate the power grid harmonic interference level, and generate a harmonic influence evaluation value;

[0172] The specific formula for evaluating the power grid harmonic interference level is:

[0173]

[0174] Calculate the harmonic influence evaluation value to obtain the power grid harmonic interference level;

[0175] where, THD represents the total harmonic distortion between the power grid and the power source, H nrepresents the amplitude of the nth harmonic component, H 1 is the amplitude of the fundamental wave, V source is the voltage amplitude of the power supply, THD grid is the total harmonic distortion of the power grid, THD source is the total harmonic distortion of the power supply, I source is the output current of the power supply, N represents the maximum number of times of harmonic analysis, and n represents the number of the harmonic currently being analyzed.

[0176] Formula The detailed explanation and the derivation process of the formula calculation are used to calculate the total harmonic distortion between the power grid and the power supply and evaluate the harmonic interference level of the power grid;

[0177] THD represents the total harmonic distortion and is used to represent the ratio of the harmonic components in the power grid or power supply waveform to the fundamental wave;

[0178] H n is the amplitude of the nth harmonic and represents the intensity of different frequency components;

[0179] H 1 is the amplitude of the fundamental wave;

[0180] V source is the voltage amplitude of the power supply and is the voltage value of the power supply output waveform;

[0181] THD grid is the total harmonic distortion of the power grid;

[0182] THD source is the total harmonic distortion of the power supply;

[0183] I source is the output current of the power supply and reflects the magnitude of the power supply output current;

[0184] Assume that the fundamental wave amplitude of the power grid H 1 = 230V, the amplitude of the second harmonic H 2 = 10V, the amplitude of the third harmonic H 3 = 5V, the amplitude of the fourth harmonic H 4 = 2V, the fundamental wave amplitude of the power supply H 1 = 220V, the total harmonic distortion of the power grid THD grid = 5.08, the total harmonic distortion of the power supply THD source = 4.5, the output current of the power supply I source = 15A, the voltage amplitude of the power supply V source = 220V;

[0185] Substitute the parameters into the formula for calculation:

[0186]

[0187] THD = 0.0493 × 0.0853 = 0.0042 = 0.42%;

[0188] The result of 0.42% indicates that the total harmonic distortion between the power grid and the power source is low, meaning that the harmonic interference between the power grid and the power source is small, and the matching degree between the output waveform of the power source and the power grid is good.

[0189] S403: According to the harmonic influence evaluation value, by adjusting the harmonic impedance parameters of the power source, optimize the harmonic matching degree between the output waveform of the power source and the power grid waveform, and generate harmonic suppression parameters;

[0190] According to the harmonic influence evaluation value, adjust the harmonic impedance parameters of the power source to optimize the harmonic matching degree between the output waveform of the power source and the power grid waveform. The purpose of adjusting the harmonic impedance of the power source is to reduce the harmonic mismatch with the power grid by changing the output characteristics of the power source, thereby reducing the harmonic interference of the power source to the power grid. The specific process of adjusting the harmonic impedance parameters includes calculating the required harmonic compensation value according to the harmonic influence evaluation results of the power grid and the power source. Assuming that the harmonic distortion of the power grid is 5.08% and the harmonic distortion of the power source is 4.5%, then the adjustment amount required for the power source is calculated according to the following formula:

[0191]

[0192] Among them, ΔZ represents the harmonic impedance adjustment amount of the power source, V source is the voltage amplitude of the power source, THD grid is the total harmonic distortion of the power grid, THD source is the total harmonic distortion of the power source, I source is the output current amplitude of the power source.

[0193] Assume that the voltage amplitude V of the power source source is 220V, and the output current I of the power source source is 10A, then the calculated harmonic impedance adjustment amount is:

[0194]

[0195] Therefore, the harmonic impedance of the power source needs to be adjusted by 0.128 Ω to optimize the harmonic matching between the power source and the power grid, and generate a record of harmonic suppression parameters.

[0196] As Figure 6 shown, the steps of calling the harmonic suppression parameters, real-time monitoring the load fluctuation of the distributed power source connection point, calculating the load change rate and predicting the load trend, and adjusting the output power and frequency regulation parameters of the distributed power source to generate the load synchronization regulation parameters are specifically as follows:

[0197] S501: Call the harmonic suppression parameters, monitor the load fluctuation at the connection point of the distributed power source, detect the amplitude and frequency of the load change, calculate the load change rate for each time period, and obtain the load change data;

[0198] When calling the harmonic suppression parameters, first monitor the load fluctuation at the connection point of the distributed power source, detect the amplitude and frequency of the load change, calculate the load change rate for each time period, and obtain the load change data. The load change rate in the power grid reflects the change speed of the load over time, and its calculation is completed by comparing the load values at consecutive moments. The calculation formula for the load change rate is as follows:

[0199]

[0200] where L rate represents the load change rate, L t is the load at the current moment, and L t+1 is the load at the next moment, with the unit of MW.

[0201] Assume that the current load L t of the power grid is 80 MW, and the load L t+1 at the next moment is 85 MW, then the load change rate is:

[0202]

[0203] The load change rate for each time period is calculated through this formula, providing data support for further analysis of the load fluctuation. Generate the load change data for subsequent load prediction and adjustment.

[0204] S502: According to the load change data, predict the change trend of the load data, analyze the impact of the load trend on the power output, and generate the calculation result of the prediction value;

[0205] According to the load change data, predict the change trend of the load data and analyze the impact of this trend on the power output. Use the linear regression or exponential smoothing method to predict the load change trend. Assume that in the past load data, the current load is 80 MW and the predicted load is 85 MW. The predicted change trend uses the following formula:

[0206] L forecast = L t +(L t+1 - L t );

[0207] where L forecast represents the predicted load value, L t is the load at the current moment, and L t+1 is the load at the next moment.

[0208] Assume the current load Lt is 80 MW, and the next moment load L t+1 is 85 MW, and the predicted load is:

[0209] L forecast = 80 MW + (85 MW - 80 MW) = 85 MW;

[0210] When analyzing the impact of load prediction results on power source output, the power source needs to adjust the output power according to the change trend of the load to ensure the balance between the load and the power source output, generate the predicted value of the load trend, and use it as the basis for subsequent power source output adjustment.

[0211] S503: According to the prediction value calculation result, adjust the output power and frequency regulation parameters of the distributed power source, optimize the response of the power source to load changes, and generate load synchronization regulation parameters;

[0212] According to the prediction value calculation result, adjust the output power and frequency regulation parameters of the distributed power source, and optimize the response of the power source to load changes. The adjustment of the power source response is based on the result of load prediction, and the goal is to make the power source power output match the load change as much as possible and maintain the stability of the power grid. Assuming that the predicted load change is 5 MW, the power source needs to adjust the power and frequency according to this change. The adjustment amount of the power source power can be calculated by the following formula:

[0213] P adjust = P t + ΔL;

[0214] Among them, P adjust represents the adjusted power source output power, with the unit of MW; P t is the current power source output power, with the unit of MW; ΔL is the load change amount, with the unit of MW.

[0215] Assume that the current power source power P t is 50 MW and the load change amount ΔL is 5 MW, then the adjusted power source output power is:

[0216] P adjust = 50 MW + 5 MW = 55 MW;

[0217] In addition, the frequency regulation parameters of the power source also need to be adjusted accordingly to adapt to the new load demand. Assume that the current frequency of the power source is 50 Hz. When the load increases by 5 MW, the frequency is adjusted by the following formula:

[0218]

[0219] Among them, f adjust represents the adjusted power source frequency, f t is the current power source frequency, ΔL is the load change amount, Lnominal is the rated load of the power supply, f nominal is the rated frequency.

[0220] Assume that the rated frequency of the power supply is 50 Hz, the rated load is 100 MW, and the load change amount is 5 MW. Then the frequency adjustment amount is:

[0221]

[0222] Generate load synchronous adjustment parameters to ensure the rapid response of the power supply to load changes and maintain the balance and stability of the power grid.

[0223] In this embodiment, by obtaining the power grid operation data in real time, the real-time state of the power grid is comprehensively reflected. Using the detection of the transient voltage drop amplitude at the connection point of the distributed power supply, the output power is adjusted in stages, effectively alleviating the voltage fluctuation problem and improving the stability of the power grid. Analyze the phase sequence relationship between the output waveform of the distributed power supply and the power grid waveform, adjust the harmonic impedance, reduce the harmonic interference, monitor the load fluctuation in real time and predict the load trend, adjust the output power and frequency adjustment parameters to ensure the synchronous operation of the distributed power supply and the power grid, and enhance the adaptive ability and emergency response ability.

[0224] Embodiment 2

[0225] Embodiment 2 of the present invention introduces a distributed power supply grid connection control system.

[0226] As Figure 7 shown, a distributed power supply grid connection control system includes:

[0227] An acquisition module configured to acquire a multi-dimensional power grid state data set;

[0228] A calculation module configured to calculate the load change trend of the distributed power supply based on the acquired multi-dimensional power grid state data set;

[0229] A generation module configured to adjust the operation parameters of the power grid according to the obtained load change trend, generate an operation parameter adjustment record; call the generated operation parameter adjustment record, detect the voltage drop amplitude at the connection point of the distributed power supply, and generate a voltage compensation gradient value; based on the generated voltage compensation gradient value, detect and analyze the phase sequence characteristics at the connection point of the distributed power supply in real time, adjust the harmonic impedance, and generate harmonic suppression parameters;

[0230] A control module configured to call the generated harmonic suppression parameters, monitor the load fluctuation at the connection point of the distributed power supply in real time, obtain load synchronous adjustment parameters, and complete the grid connection control of the distributed power supply.

[0231] The detailed steps are the same as those of a distributed power supply grid connection control method provided in Embodiment 1 and will not be elaborated here.

[0232] Embodiment III

[0233] Embodiment III of the present invention provides a computer-readable storage medium.

[0234] A computer-readable storage medium has a program stored thereon, and when the program is executed by a processor, it implements the steps in a distributed power grid connection control method as described in Embodiment I of the present invention.

[0235] The detailed steps are the same as those in the distributed power grid connection control method provided in Embodiment I, and will not be elaborated here.

[0236] Embodiment IV

[0237] Embodiment IV of the present invention provides an electronic device.

[0238] An electronic device includes a memory, a processor, and a program stored on the memory and running on the processor. When the processor executes the program, it implements the steps in a distributed power grid connection control method as described in Embodiment I of the present invention.

[0239] The detailed steps are the same as those in the distributed power grid connection control method provided in Embodiment I, and will not be elaborated here.

[0240] Embodiment V

[0241] Embodiment V of the present invention provides a computer program product.

[0242] A computer program product includes software code, and the program in the software code implements the steps in a distributed power grid connection control method as described in Embodiment I of the present invention.

[0243] The detailed steps are the same as those in the distributed power grid connection control method provided in Embodiment I, and will not be elaborated here.

[0244] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes. The solutions in the embodiments of the present invention can be implemented in various computer languages, for example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0245] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general purpose computers, special purpose computers, embedded processors, or other programmable data processing devices to produce a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in one block or multiple blocks.

[0246] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in one block or multiple blocks.

[0247] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in one block or multiple blocks.

[0248] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0249] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

[0250] The above description is only the preferred embodiments of this embodiment and is not used to limit this embodiment. For those skilled in the art, this embodiment can have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this embodiment shall be included within the protection scope of this embodiment.

Claims

1. A distributed power grid-connected control method, characterized in that: include: Obtain a multi-dimensional power grid status data set; Calculate the load change trend of distributed generation based on the acquired multi-dimensional grid status data set; Adjust the operation parameters of the power grid according to the obtained load change trend, and generate an operation parameter adjustment record; Call the generated operation parameter adjustment record, detect the voltage drop amplitude of the distributed power grid connection point, and generate the voltage compensation gradient value; Based on the generated voltage compensation gradient value, the phase sequence characteristics of the distributed power grid connection point are detected and analyzed in real time, the harmonic impedance is adjusted, and the harmonic suppression parameters are generated; The generated harmonic suppression parameters are called to monitor the load fluctuation of the distributed power grid connection point in real time, obtain the load synchronization adjustment parameters, and complete the grid connection control of the distributed power source.

2. A distributed power grid-connected control method as claimed in claim 1, characterized in that: In the process of obtaining a multidimensional power grid status data set, real-time power grid operation data including instantaneous voltage, frequency fluctuation, load change rate and power factor are obtained, and the obtained real-time power grid operation data are aggregated in time series, and the statistical characteristics in each time interval are calculated to obtain a time series aggregated data set. The aggregated data in the obtained time series aggregated data set are aligned according to the time dimension and multi-dimensionally combined, and the power grid operation stability is calculated to obtain a multidimensional power grid status data set.

3. A distributed power grid-connected control method as claimed in claim 1, characterized in that: The output power of distributed power sources and grid load demand data are extracted from the acquired multi-dimensional grid status data set, and the changing trends of power output and load demand in multiple time periods are calculated to obtain the load change trend of distributed power sources; the fluctuation range of grid load is evaluated according to the obtained load change trend to obtain load fluctuation data; the operating parameters of the grid are adjusted in combination with the obtained load fluctuation data to obtain the operating parameter adjustment record.

4. A distributed power grid-connected control method as claimed in claim 1, characterized in that: The generated operating parameter adjustment record is called to obtain the grid load demand change data, the voltage drop amplitude is detected according to the acquired data, the real-time voltage drop data is generated, and the voltage transient drop amplitude is classified, and the adjustment requirements of various change amplitudes on the power supply output power are analyzed to generate the drop amplitude classification result; according to the drop amplitude classification result, the output power of the distributed power supply is adjusted in stages, the power supply power change is calculated, and the voltage compensation gradient value is generated.

5. A distributed power grid connection control method as claimed in claim 1, characterized in that: The generated voltage compensation gradient value is called to monitor the phase sequence characteristics of the distributed power grid connection point, analyze the phase sequence relationship between the grid waveform and the power supply output waveform, identify the phase sequence difference, generate phase sequence relationship characteristic data, detect the harmonic impact between the distributed power supply output waveform and the grid waveform, calculate the harmonic waveform parameters, evaluate the grid harmonic interference level, generate the harmonic impact assessment value, optimize the harmonic matching degree between the power supply output waveform and the grid waveform by adjusting the harmonic impedance parameters of the power supply, and generate the harmonic suppression parameters.

6. A distributed power grid-connected control method as claimed in claim 1, characterized in that: Call the generated harmonic suppression parameters, monitor the load fluctuations of the distributed power grid connection point, detect the amplitude and frequency of load changes, calculate the load change rate in each time period, obtain load change data, predict the change trend of load data, analyze the impact of load trends on power supply output, generate predicted value calculation results, adjust the output power and frequency regulation parameters of distributed power supplies, optimize the response of power supply to load changes, generate load synchronization regulation parameters, and combine the generated load synchronization regulation parameters to control the grid connection of distributed power supplies.

7. A distributed power grid-connected control system, characterized in that: include: An acquisition module, configured to acquire a multi-dimensional power grid status data set; A calculation module, configured to calculate a load change trend of a distributed power source based on the acquired multi-dimensional grid state data set; A generation module is configured to adjust the operation parameters of the power grid according to the obtained load change trend and generate an operation parameter adjustment record; call the generated operation parameter adjustment record, detect the voltage drop amplitude of the distributed power grid connection point, and generate a voltage compensation gradient value; based on the generated voltage compensation gradient value, real-time detect and analyze the phase sequence characteristics of the distributed power grid connection point, adjust the harmonic impedance, and generate harmonic suppression parameters; The control module is configured to call the generated harmonic suppression parameters, monitor the load fluctuation of the distributed power grid connection point in real time, obtain the load synchronization adjustment parameters, and complete the grid connection control of the distributed power source.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of a distributed power grid-connected control method as described in any one of claims 1 to 6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of a distributed power grid-connected control method as described in any one of claims 1-6 are implemented.

10. A computer program product comprising software code, characterized in that The program in the software code executes the steps of a distributed power grid-connected control method as described in any one of claims 1-6.

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