Photovoltaic inverter operation control system and method based on multi-source data

Abstract

The invention discloses a photovoltaic inverter operation control system and method based on multi-source data, and belongs to the technical field of inverter control. According to the method, a loop is built in a current collection circuit associated with an inverter; judging whether the photovoltaic power station has a power generation condition, and generating a control instruction; after the commissioning instruction is triggered, commissioning is delayed when the current exceeds the standard; a vacuum contactor of the main on-off loop is controlled to be switched on, and the suppression loop is connected into the circuit; after the current of the main loop is stable, screening an optimal path, switching to a bypass loop for operation, and disconnecting the suppression loop; when the voltage suddenly rises or drops, the closing rate of the main on-off loop is adjusted; when the shutdown instruction is triggered, the main on-off loop is controlled to be opened, the main connection between the current collection line and the inverter is cut off, and the bypass loop keeps running; after the main loop is opened, detecting the current and voltage states of the bypass loop, and cutting off the bypass loop after determining that no abnormity exists; and when the voltage fluctuation is detected to exceed the standard, the locking is triggered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inverter control, and particularly relates to a photovoltaic inverter operation control system and method based on multi-source data. BACKGROUND

[0002] As a core clean energy, photovoltaic power generation is developed on a large scale. As a core component for connecting a photovoltaic system and a power grid, the stability and efficiency of operation control of an inverter directly determine the power generation efficiency of a power station and the safety of power grid connection. As a key carrier for transmitting power by the inverter, the on-off control, path switching and fault suppression of a collection line are core links of operation control of the inverter. When put into operation, the inverter needs to avoid the magnetic core saturation caused by the closing current impact. In operation, the inverter needs to reduce the path transmission loss. When stopped, the inverter needs to prevent voltage fluctuation from spreading to the power grid.

[0003] The traditional operation only relies on fixed closing rate control, does not combine the accurate judgment of low load states of the power grid side and the inverter side, and lacks predictive control of the closing current. The matching degree of the suppression loop access time and the resistance current limiting effect is low. The bypass loop is mostly dependent on manual presetting or a single distance parameter, and does not combine the correlation between the main power generation area of the photovoltaic array and the loop orientation. The non-optimal path is easily selected, which increases the transmission loss and reduces the power generation efficiency of the power station. In the operation and shutdown process, the monitoring of the grid-connected voltage fluctuation is mostly after the standard remediation, and lacks a trend prediction and dynamic adjustment mechanism. The closing or opening rate adjustment is lagging, which easily leads to the spread of the fluctuation to the power grid. SUMMARY

[0004] The present application relates to the technical field of inverter control, and particularly relates to a photovoltaic inverter operation control system and method based on multi-source data.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: In a first aspect, the present application provides a photovoltaic inverter operation control method based on multi-source data, comprising the following steps: In the collection line associated with the inverter, a main on-off loop, a bypass loop and a suppression loop are built. Multi-source data is collected to determine whether the photovoltaic power station has power generation conditions, and control instructions, including operation instructions and shutdown instructions, are generated. When the operation instruction is triggered, the current of the power grid side and the inverter side is detected by a detection device to determine whether the current is in a low load state. When the current is out of standard, the operation is delayed. An LSTM prediction model is used to control the closing of the vacuum contactor of the main on-off loop, the suppression loop is connected to the circuit, and the resistance is used to slow down the current rising rate at the moment of closing. After the main circuit current is stable, the optimal path is selected according to the azimuth relationship between the main circuit and the bypass circuit and the photovoltaic power station, the bypass circuit is switched to run, and the suppression circuit is disconnected; the grid-connected voltage is monitored in real time, and when the voltage rises or drops suddenly, the closing speed of the main circuit breaker is adjusted; When the shutdown instruction is triggered, the main circuit breaker is opened to disconnect the main connection between the collector circuit and the inverter, and the bypass circuit remains running; after the main circuit is opened, the current and voltage states of the bypass circuit are detected, and after confirming that there is no abnormal overcurrent or overvoltage, the bypass circuit is disconnected; when the voltage fluctuation exceeds the standard, the latching is triggered, and the opening operation is suspended.

[0006] In combination with the first aspect, in a first implementation manner of the first aspect of the present application, the main circuit breaker, the bypass circuit and the suppression circuit are built in the collector circuit associated with the inverter, including: The main circuit breaker is responsible for the main control of the collector circuit operation and shutdown, the bypass circuit is responsible for the current shunt after the main circuit is stable, and the suppression circuit is responsible for suppressing the excitation inrush current and voltage fluctuation during operation; The main circuit breaker is connected in series between the inverter output end and the collector circuit bus, forming a main current channel, and the disconnecting switch, the vacuum contactor and the current transformer are connected in series in the circuit, the voltage monitoring points are connected in parallel at both ends of the circuit, the voltage transformer is connected, and the voltage at both ends of the main circuit is monitored in real time; the bypass circuit is connected in parallel between the vacuum contactors of the main circuit breaker, forming a structure in parallel with the main circuit breaker and the bypass circuit, the bypass disconnecting switch, the bypass contactor and the current transformer are arranged in the circuit, and the bypass circuit is grouped according to the azimuth of the photovoltaic array; the suppression circuit is connected in series between the vacuum contactor of the main circuit breaker and the collector circuit bus, forming a series path, and the current limiting resistor and the suppression circuit contactor are arranged in the circuit, and the voltage monitoring points are connected in parallel at both ends of the suppression circuit to assist in judging the voltage division when the resistor is connected.

[0007] In combination with the first aspect, in a second implementation manner of the first aspect of the present application, the multi-source data is collected, it is judged whether the photovoltaic power station has power generation conditions, and control instructions including operation instructions and shutdown instructions are generated, including: The multi-source data includes photovoltaic component working condition data, power grid access state data, environmental interference data and equipment health state data, and the effective threshold of each type of multi-source data is preset based on the design standard and equipment parameters of the photovoltaic power station; the multi-source data is collected, data preprocessing is performed, the multi-source data is compared with the effective threshold, when the component has power generation capacity, the power grid has receiving capacity and the equipment has operation safety, the operation instruction is generated, otherwise the shutdown instruction is generated.

[0008] In a third implementation form of the first aspect, when the operation instruction is triggered, whether the grid-side and inverter-side currents are in the low-load state is determined by detecting devices, and when the currents exceed the threshold, the operation is delayed, including: The quantification threshold of the low-load state is set based on the rated parameters of the inverter, the design standard of the power collection line, and the excitation inrush current suppression target. The detection devices on the grid side and the inverter side are pre-calibrated. When the operation instruction is triggered, the collection of the grid-side and inverter-side currents is triggered, and data preprocessing is performed. When the grid-side current is not greater than the low-load threshold and the inverter-side current is not greater than the low-load threshold, it is determined that the low-load state is met, otherwise it is determined that the currents exceed the threshold. When the currents exceed the threshold, the main on-off circuit closing action is frozen, and an initial delay duration is set. After the delay duration ends, it is determined again whether the low-load requirement is met. If the currents still exceed the threshold, the verification process is repeated until the low-current working condition requirement is met.

[0009] In a fourth implementation form of the first aspect, the vacuum contactor of the main on-off circuit is controlled using the LSTM prediction model to connect the suppression circuit to the circuit, and the resistance is used to slow down the current rise rate at the moment of closing, including: The time sequence data of the past closing process of the photovoltaic power station is collected to build a training sample library, input the time sequence features including the grid-side voltage sequence, the inverter-side initial current sequence, the light intensity sequence, the component temperature sequence, and the real-time temperature sequence of the suppression resistance, and output the time sequence label, specifically the current rise sequence after closing. The data is cleaned and normalized, and divided into a training set and a validation set. The LSTM prediction model is constructed to minimize the mean square error between the predicted current sequence and the actual sequence, and the Adam optimizer is used for training to ensure that the prediction error is within the allowed range. The current time sequence features are input into the LSTM model to output the prediction result, specifically the current rise curve. The predicted peak value, predicted rise slope, and predicted magnetic core saturation time are extracted based on the curve to generate the control parameters of the closing and suppression circuits. Based on the control parameters, the step closing instruction is sent to the vacuum contactor, and the early closing instruction is sent to the suppression circuit contactor.

[0010] In a fifth implementation form of the first aspect, after the main circuit current is stabilized, the optimal path is selected according to the orientation relationship between the main circuit and the bypass circuit and the photovoltaic power station, the bypass circuit is switched to operate, and the suppression circuit is disconnected, including: The pre-stored power station topology data is called, which defines the physical connection relationship and electrical path of all bypass circuits and each group of photovoltaic arrays. The data attributes include circuit identification, associated array group, orientation coordinates, and current state. The associated array group is a subset of photovoltaic arrays connected by the circuit. The orientation coordinates are the relative electrical distance between the circuit access point and the array group. The current state is the state of the disconnector and contactor of the bypass circuit. The screening principle is set to select the bypass circuit closest to the current main power generation array, real-time power generation data of each photovoltaic array group is obtained, one or more array groups that contribute to the main power generation are identified, the identified main power generation array group is matched with the array group associated with each bypass circuit, a path priority score of each bypass circuit is calculated, the score logic is that if the array group associated with a bypass circuit overlaps with the current main power generation array group to the largest extent, the score of the bypass circuit is the highest, the bypass circuit with the highest path priority score is selected as the target bypass circuit for this switching, when multiple bypass circuits with the same score appear, one with the shortest electrical path is selected, an operation blocking signal is sent to the vacuum contactor of the main on-off circuit, the bypass disconnecting switch of the target bypass circuit is closed, then the bypass contactor of the circuit is closed, when it is confirmed that the target bypass circuit has stably carried the current and the main circuit current starts to drop and stabilizes at a threshold value, it is determined that the current transfer is successful, a trip command is sent to the suppression circuit contactor to cut it out of the circuit, and the operation blocking of the vacuum contactor of the main on-off circuit is released.

[0011] In combination with the first aspect, in a sixth implementation manner of the first aspect of the application, the real-time grid-connected voltage is monitored, and when a voltage surge or drop trend occurs, the closing rate of the main on-off circuit is adjusted, including: The grid-connected point voltage value is sampled, linear regression analysis is performed on the collected voltage sequence in each analysis time window, the instantaneous slope and acceleration are calculated, the drop trend indicates that the instantaneous slope is negative and the absolute value exceeds the drop trend threshold, the surge trend indicates that the instantaneous slope is positive and the absolute value exceeds the rise trend threshold, and the stable state indicates that the absolute value of the instantaneous slope is below the threshold, when the drop trend is determined, the control target is to slow down the voltage drop rate and increase the voltage, and when the surge trend is determined, the control target is to slow down the voltage rise rate and suppress the voltage.

[0012] In combination with the first aspect, in a seventh implementation manner of the first aspect of the application, after the shutdown instruction is triggered, the main on-off circuit is controlled to trip to cut off the main connection between the collector circuit and the inverter, and the bypass circuit remains in operation, including: A trip instruction is sent to the control unit of the main on-off circuit to start the main connection cutting process, the bypass circuit maintains the original operating state to ensure that the current is continuously carried, during the tripping process, the operating state of the main on-off circuit is monitored in real time to confirm that the contacts are gradually separated and the main connection between the collector circuit and the inverter is gradually disconnected, when the main on-off circuit feedbacks a tripping-in-place signal and it is monitored that the main circuit current has dropped to zero, it is determined that the main connection is successfully cut off, it is synchronously confirmed that the bypass circuit still remains in normal operation and the current and voltage parameters are stable and are not affected by the tripping of the main circuit, the current operation is completed and the state is recorded.

[0013] In combination with the first aspect, in an eighth implementation manner of the first aspect of the application, after the main circuit is tripped, the current and voltage states of the bypass circuit are detected, and after it is confirmed that there is no abnormal overcurrent or overvoltage, the bypass circuit is cut off, including: After the main circuit is tripped, it is first confirmed that the current of the main circuit has dropped to zero and remains stable, and then the bypass circuit state detection process is started; the current and voltage of the bypass circuit are monitored in real time, and it is judged whether there is abnormal overcurrent or abnormal overvoltage; if the current and voltage of the bypass circuit are both in the normal range and there is no abnormal fluctuation during continuous monitoring, it is determined that the cut-off condition is met, and the cut-off operation is prepared to be performed; the bypass circuit cut-off program is started, and the cut-off speed is controlled according to the preset logic; after the cut-off action is completed, it is confirmed that the current of the bypass circuit has dropped to zero and the voltage has returned to a stable state, and it is determined that the cut-off is successful.

[0014] In a second aspect, the application provides a photovoltaic inverter operation control system based on multi-source data, including: A control instruction generation module includes a circuit building unit and a control instruction generation unit; wherein in the power collection circuit associated with the inverter, the circuit building unit builds a main on-off circuit, a bypass circuit and a suppression circuit; the control instruction generation unit collects multi-source data, judges whether the photovoltaic power station has power generation conditions, generates control instructions, including commissioning instructions and shutdown instructions; A commissioning control module includes a low-load state detection unit and an LSTM closing control unit; wherein the low-load state detection unit confirms whether the current at the grid side and the inverter side is in a low-load state through detection equipment after the commissioning instruction is triggered, and delays commissioning when the current exceeds the standard; the LSTM closing control unit uses an LSTM prediction model to control the closing of the vacuum contactor of the main on-off circuit, connects the suppression circuit to the circuit, and uses resistance to slow down the current rising rate at the moment of closing; A circuit control module includes a path optimization and switching unit and a voltage monitoring and adjusting unit; wherein the path optimization and switching unit selects the optimal path according to the positional relationship between the main circuit and the bypass circuit and the photovoltaic power station after the current of the main circuit is stable, switches to the bypass circuit operation, and disconnects the suppression circuit; the voltage monitoring and adjusting unit monitors the grid-connected voltage in real time, and adjusts the closing rate of the main on-off circuit when there is a trend of sudden voltage rise or drop; A shutdown control module includes a shutdown control unit, a bypass circuit cut-off control unit and a voltage fluctuation locking unit; wherein the shutdown control unit controls the main on-off circuit to be tripped after the shutdown instruction is triggered, cuts off the main connection between the power collection circuit and the inverter, and keeps the bypass circuit running; after the main circuit is tripped, the bypass circuit cut-off control unit detects the current and voltage states of the bypass circuit, and cuts off the bypass circuit after confirming that there is no abnormal overcurrent or overvoltage; the voltage fluctuation locking unit triggers the lock when the detected voltage fluctuation exceeds the standard, and suspends the tripping operation.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention establishes a three-circuit architecture of main switching, bypass, and suppression, and combines multi-source data to determine power generation conditions. Before commissioning, it verifies the low-load state to avoid blind closing. It introduces an LSTM prediction model to dynamically optimize the closing rate of the vacuum contactor, and uses the suppression circuit resistor to limit current and reduce current surges.

[0016] 2. After the main circuit is stabilized, this invention selects the optimal path based on the orientation relationship between the main and bypass circuits and the photovoltaic array, combined with the overlap of the main power generation array, to ensure that the path matches the core area of ​​power transmission, reduce transmission loss, and improve the operating efficiency of the power station.

[0017] 3. This invention monitors the grid-connected voltage in real time and captures sudden rises and falls, dynamically adjusts the closing rate of the main on / off circuit, and achieves proactive prevention and control through trend prediction and real-time adjustment to avoid fluctuations spreading to the power grid; when the voltage exceeds the standard during a shutdown, it triggers immediate blocking and resumes operation after stabilization, ensuring grid-friendliness. Attached Figure Description

[0018] Fig. 1 This is a schematic diagram of the steps of a photovoltaic inverter operation control method based on multi-source data according to the present invention; Fig. 2 This is a system structure diagram of a photovoltaic inverter operation control system based on multi-source data according to the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example: Figs. 1-2 As shown, the present invention provides a technical solution: like Fig. 1 As shown, this application provides a photovoltaic inverter operation control method based on multi-source data, including the following steps: Step S100: In the collector lines associated with the inverter, build the main on / off circuit, bypass circuit and suppression circuit; collect multi-source data, determine whether the photovoltaic power station has the conditions for power generation, and generate control commands, including commissioning commands and shutdown commands; Specifically, the main switching circuit is responsible for the main control switching of the collector line during commissioning and shutdown, the bypass circuit is responsible for the current diversion after the main circuit stabilizes, and the suppression circuit is responsible for suppressing inrush current and voltage fluctuations during commissioning. The main on-off circuit is connected in series between the inverter output end and the power collection circuit bus, forming a main current channel, and the disconnector, the vacuum contactor and the current transformer are connected in series in the circuit, and the voltage monitoring points are connected in parallel at both ends of the circuit, and the voltage transformer is connected, and the voltage at both ends of the main circuit is monitored in real time; the bypass circuit is connected in parallel to the vacuum contactor of the main on-off circuit, forming a structure in parallel with the main on-off circuit and the bypass circuit, and the bypass disconnector, the bypass contactor and the current transformer are arranged in the circuit, and the bypass circuit is grouped according to the orientation of the photovoltaic array; the suppression circuit is connected in series between the vacuum contactor of the main on-off circuit and the power collection circuit bus, forming a series path, and the current limiting resistor and the suppression circuit contactor are arranged in the circuit, and the voltage monitoring points are connected in parallel at both ends of the suppression circuit to assist in judging the voltage division when the resistor is connected.

[0021] Further, the multi-source data includes photovoltaic component working condition data, power grid access state data, environmental interference data and equipment health state data, and based on photovoltaic power station design standards and equipment parameters, the effective threshold of each type of multi-source data is preset; the multi-source data is collected, data preprocessing is performed, the multi-source data is compared with the effective threshold, when the component has power generation capacity, the power grid has receiving capacity and the equipment has operation safety, the operation instruction is generated, otherwise the shutdown instruction is generated.

[0022] In a specific embodiment, the embodiment is based on a 300kW photovoltaic inverter and a 10kV power collection circuit scene, and the experimental time is 9:10 in the morning on a sunny day.

[0023] The main on-off circuit is connected in series between the 300kW inverter output end and the 10kV power collection bus, and the GN30-12 / 200 disconnector (rated current 200A), the JCZ5-12D / 200 vacuum contactor (rated current 200A, on-off time 45ms), the LMZJ1-0.5 current transformer (turns ratio 200 / 5A) and the JDZJ-10 voltage transformer are connected in series, and the voltage is monitored at both ends; the bypass circuit is grouped according to the east and west arrays (300kW capacity corresponds to two groups of small arrays), each group is connected in parallel to the vacuum contactor, and the GW9-12 / 200 disconnector and the CJX2-200 contactor are arranged; the suppression circuit is connected in series between the vacuum contactor and the bus, including a 10Ω / 5kW current limiting resistor and an LC1D200 contactor, and voltage monitoring points are connected at both ends.

[0024] Pre-set effective threshold: single-component open-circuit voltage 32-40V, array total power ≥50kW, grid-connected voltage 9.5-10.5kV, frequency 49.5-50.5Hz, light intensity ≥200W / m², inverter insulation resistance ≥100MΩ. Real-time data collection: single-component open-circuit voltage 36V, array total power 280kW, grid-connected voltage 10.0kV, frequency 50.1Hz, harmonic distortion rate 2.2%, light intensity 800W / m², ambient temperature 25℃, inverter insulation resistance 500MΩ, contactor coil temperature 40℃. After data preprocessing, the comparison threshold: the components, power grid and equipment all meet the standards, and the operation instruction is generated.

[0025] Step S200: When the operation instruction is triggered, it is confirmed by the detection equipment whether the current on the grid side and the inverter side is in a low load state, and the operation is delayed when the current exceeds the standard; the vacuum contactor of the main on-off circuit is controlled to close by using the LSTM prediction model, and the suppression circuit is connected to the circuit to slow down the current rising rate at the moment of closing; Specifically, based on the rated parameters of the inverter, the design standards of the power collection line and the excitation inrush suppression target, the quantitative threshold of the low load state is set; the detection equipment on the grid side and the inverter side is pre-calibrated; when the operation instruction is triggered, the current collection on the grid side and the inverter side is triggered, and the data is pre-processed; when the current on the grid side is not greater than the low load threshold and the current on the inverter side is not greater than the low load threshold, it is determined that it is in a low load state, otherwise it is determined that the current exceeds the standard; when the current exceeds the standard, the closing action of the main on-off circuit is frozen, and the initial delay time is set; after the delay time is over, it is determined again whether the low load requirement is met, if it still exceeds the standard, the verification process is repeated until the low current working condition requirement is met.

[0026] Further, the time sequence data of the past closing process of the photovoltaic power station is collected, a training sample library is constructed, time sequence features are input, including grid side voltage sequence, inverter side initial current sequence, light intensity sequence, component temperature sequence and suppression resistance real-time temperature sequence, and time sequence labels are output, specifically the current rising sequence after closing; the data is cleaned and normalized, and divided into training set and validation set; the LSTM prediction model is constructed, the mean square error of the predicted current sequence and the actual sequence is minimized as the target, the Adam optimizer is used for training, and the prediction error is ensured to be within the allowable range; the current time sequence features are input into the LSTM model, and the prediction result is output, specifically the current rising curve, the predicted peak value, the predicted rising slope and the predicted magnetic core saturation time are extracted based on the curve, and the control parameters of the closing and suppression circuit are generated; based on the control parameters, the step closing instruction is sent to the vacuum contactor, and the advance closing instruction is sent to the suppression circuit contactor.

[0027] In a specific embodiment, the embodiment is based on a 300kW photovoltaic inverter and a 10kV power collection line scenario, and the commissioning instruction triggering time is 9:15 on a sunny day (S100 commissioning instruction is received).

[0028] In the low load state confirmation stage, based on the rated current 17.32A of the 300kW inverter (10kV system), the low load threshold is set to 10% of the rated value, that is, 1.75A; the pre-calibration grid side and inverter side LMZJ1-0.5 type current transformer (ratio 200 / 5A) is calibrated, and the accuracy after calibration reaches 0.5 level. After the commissioning instruction is triggered, the grid side current is 1.2A and the inverter side current is 0.8A, both of which are lower than 1.75A after filtering and pretreatment, and it is determined that the low load state meets the standard. Counterexample: if the grid side current is 2.0A (over standard), the freeze combination is closed and delayed for 10 seconds for re-measurement, and the second acquisition value is 1.3A which meets the standard.

[0029] In the LSTM control stage, the training sample library is the past 800 times of closing timing data (50ms step), the input features include grid voltage 10.0-10.05kV fluctuation sequence, inverter initial current 0.8A, illumination 800W / m², component temperature 25℃, and suppression resistance (10Ω / 5kW) temperature 23℃; the model is 2-layer LSTM (64+32 nodes), and the Adam optimizer (learning rate 0.001) is trained, and the verification set MSE=0.006A² after training. After the current feature is input, the model predicts the current peak value 16A after closing, the rising slope 0.18A / ms, and the saturation time 30ms, and generates the control parameters: the vacuum contactor step closing rate is 0.12 seconds, and the suppression loop contactor closes 5ms in advance. After execution, the actual measured current peak value is 16.3A, the slope is 0.19A / ms, and the error meets the requirements.

[0030] Step S300: After the main loop current is stable, the optimal path is selected according to the orientation relationship of the main loop and the bypass loop with the photovoltaic power station, the bypass loop is switched to run, and the suppression loop is disconnected; the grid voltage is monitored in real time, and when the voltage rises or drops suddenly, the closing rate of the main on-off loop is adjusted; Specifically, the pre-stored power station topology data is called, which defines the physical connection relationship and electrical path of all bypass loops and each group of photovoltaic arrays, and the data attributes include loop identification, associated array group, orientation coordinates and current state, the associated array group is the subset of photovoltaic arrays connected by the loop, the orientation coordinates are the relative electrical distance between the loop access point and the array group, and the current state is the state of the disconnector and contactor of the bypass loop. The screening principle is set to select the bypass circuit closest to the current main power generation array, real-time power generation data of each photovoltaic array group is obtained, one or more array groups that contribute to the main power generation are identified, and the identified main power generation array group is matched with the array group associated with each bypass circuit; the path priority score of each bypass circuit is calculated, and the score logic is that if the array group associated with a bypass circuit overlaps with the current main power generation array group to the maximum extent, the score of the bypass circuit is the highest; the bypass circuit with the highest path priority score is selected as the target bypass circuit for this switching, when multiple bypass circuits with the same score appear, the bypass circuit with the shortest electrical path is selected; an operation blocking signal is sent to the vacuum contactor of the main on-off circuit, the bypass disconnecting switch of the target bypass circuit is closed, then the bypass contactor of the circuit is closed; when it is confirmed that the target bypass circuit has stably carried the current and the main circuit current starts to decrease and stabilizes at a threshold value, it is determined that the current transfer is successful; a tripping instruction is sent to the suppression circuit contactor to cut it out of the circuit; the operation blocking of the vacuum contactor of the main on-off circuit is released.

[0031] Further, the grid-connected point voltage value is sampled, in each analysis time window, linear regression analysis is performed on the collected voltage sequence, the instantaneous slope and acceleration are calculated; the sudden drop trend indicates that the instantaneous slope is negative and the absolute value exceeds the drop trend threshold; the sudden rise trend indicates that the instantaneous slope is positive and the absolute value exceeds the rise trend threshold; the stable state indicates that the absolute value of the instantaneous slope is below the threshold; when the sudden drop trend is determined, the control target is to slow down the voltage drop rate and increase the voltage; when the sudden rise trend is determined, the control target is to slow down the voltage rise rate and suppress the voltage.

[0032] In a specific embodiment, the present embodiment is based on a 300kW photovoltaic inverter and a 10kV power collection line scenario, the main circuit is closed for 9:20, at which time the main circuit current is 17A (fluctuation ≤2%).

[0033] The pre-stored power station topology data is that the bypass circuit is divided into east and west groups, the east bypass is associated with the east zone array and has an electrical distance of 100m, the west bypass is associated with the west zone array and has a distance of 130m, and both groups are in a "disconnected isolating switch and disconnected contactor" standby state. Real-time array power is collected: east zone 160kW, west zone 120kW, and the east zone is identified as the main power generation (accounting for 53.3%). The score is calculated: the east bypass is associated with the main array (overlap degree 100%, score 1), the west bypass has no overlap (score 0), and the east bypass is selected as the target. The switching is executed: a blocking signal is sent to the main on-off circuit, the east bypass disconnecting switch is closed (feedback in place 18ms), and then the contactor is closed; 300ms later, the east bypass current rises to 16.5A, the main circuit current decreases to 8A (stable ≤10A), and it is determined that the transfer is successful; a tripping instruction is sent to the suppression circuit (tripping time 40ms), and the main circuit blocking is released.

[0034] Set voltage surge threshold: instantaneous slope > 0.003 kV / ms, analysis window 50 ms. Real-time acquisition of grid voltage during switching: from 10.0 kV to 10.2 kV, linear regression calculation of instantaneous slope 0.004 kV / ms (over threshold, determine surge). Immediately adjust the main break circuit closing rate (originally 0.12 seconds to 0.18 seconds), 100 ms later the voltage stabilizes to 10.1 kV, the slope drops to 0.002 kV / ms (returns to stable).

[0035] Step S400: When the shutdown instruction is triggered, control the main break circuit to open, cut off the main connection between the collector circuit and the inverter, and keep the bypass circuit running; after the main circuit is opened, detect the current and voltage state of the bypass circuit, confirm that there is no abnormal overcurrent or overvoltage, and then cut off the bypass circuit; when the voltage fluctuation exceeds the standard, trigger the lockout and suspend the opening operation.

[0036] Specifically, a trip command is sent to the control unit of the main break circuit to start the main connection cut-off process, and the bypass circuit maintains the original running state to ensure continuous current carrying; during the trip process, the action state of the main break circuit is monitored in real time to confirm that the contacts are gradually separated and the main connection between the collector circuit and the inverter is gradually disconnected; when the main break circuit feedback trip-in-place signal and the main circuit current is detected to have dropped to zero, it is determined that the main connection is successfully cut off; it is simultaneously confirmed that the bypass circuit still maintains normal operation, the current and voltage parameters are stable, and the operation is completed and the state is recorded.

[0037] Further, after the main circuit is tripped, it is first confirmed that the main circuit current has dropped to zero and remains stable, and then the bypass circuit state detection process is started; the current and voltage of the bypass circuit are monitored in real time to determine whether there is abnormal overcurrent or abnormal overvoltage; if the current and voltage of the bypass circuit are within the normal range without any abnormal fluctuations during continuous monitoring, it is determined that the cut-off condition is met and the cut-off operation is prepared to be performed; the bypass circuit cut-off program is started and the cut-off speed is controlled according to the preset logic; after the cut-off action is completed, it is confirmed that the bypass circuit current has dropped to zero and the voltage has returned to a stable state, and it is determined that the cut-off is successful.

[0038] In a specific embodiment, the present embodiment is based on a 300kW photovoltaic inverter and a 10kV collector circuit scenario, and the shutdown instruction triggering time is 17:40 in the evening (light intensity drops to 190W / m²).

[0039] The opening command is sent to the main on-off circuit control unit, and the JCZ5-12D / 200 type vacuum contactor is started to open (action time 45 ms). During the opening process, the main circuit current is monitored: gradually decreases from 16.5 A, decreases to 8 A at 25 ms, and decreases to 0 at 45 ms, and the current is confirmed to be zero for 50 ms, and it is determined that the main connection is cut off. The east bypass circuit is monitored synchronously: the current rises from 0 to 16.2 A (fluctuation ≤3%), and the voltage is 10.0 kV (stably in the range of 9.5-10.5 kV), and it is confirmed to be normal operation.

[0040] After the main circuit is opened, the bypass circuit detection is started: the current 16.2 A (normal range 0-18 A) and the voltage 10.0 kV (no overvoltage / undervoltage) are collected in real time, there is no fluctuation for 200 ms continuously, and the cut-off condition is met. According to the preset logic (0.15 second opening speed), the cut-off is started, and during the process, the current smoothly decreases from 16.2 A to 0 (time consumption 150 ms), and finally the voltage is stably at 10.1 kV, and it is determined that the cut-off is successful.

[0041] The power grid disturbance during opening simulation: the voltage suddenly rises to 10.6 kV (over the threshold of 10.5 kV), which immediately triggers the lockout and suspends the bypass cut-off; 1 second later, the voltage falls to 10.2 kV and stabilizes, the lockout is released, and the cut-off continues from the suspended step, and finally the operation is completed.

[0042] As shown in Fig. 2 The application provides a photovoltaic inverter operation control system based on multi-source data, which comprises: A control instruction generation module comprises a circuit building unit and a control instruction generation unit; wherein, in the power collection circuit associated with the inverter, the circuit building unit builds a main on-off circuit, a bypass circuit and a suppression circuit; the control instruction generation unit collects multi-source data, judges whether the photovoltaic power station has power generation conditions, generates control instructions, including operation instruction and shutdown instruction; An operation control module comprises a low-load state detection unit and an LSTM closing control unit; wherein, after the operation instruction is triggered, the low-load state detection unit confirms whether the current on the grid side and the inverter side is in a low-load state through detection equipment, and delays operation when the current exceeds the standard; the LSTM closing control unit uses an LSTM prediction model to control the vacuum contactor of the main on-off circuit to close, connects the suppression circuit to the circuit, and uses resistance to slow down the current rising rate in the closing moment; A circuit control module comprises a path optimization and switching unit and a voltage monitoring and adjusting unit; wherein, after the main circuit current is stable, the path optimization and switching unit selects the optimal path according to the orientation relationship between the main circuit and the bypass circuit and the photovoltaic power station, switches to the bypass circuit operation, and disconnects the suppression circuit; the voltage monitoring and adjusting unit monitors and adjusts the grid-connected voltage in real time, and adjusts the closing rate of the main on-off circuit when the voltage suddenly rises or drops; The shutdown control module comprises: a shutdown control unit, a bypass circuit cut-off control unit and a voltage fluctuation locking unit; wherein, the shutdown control unit controls the main on-off circuit to be tripped when the shutdown instruction is triggered, the main connection between the collector circuit and the inverter is cut off, and the bypass circuit keeps running; after the main circuit is tripped, the bypass circuit cut-off control unit detects the current and voltage state of the bypass circuit, and cuts off the bypass circuit after confirming that there is no abnormal overcurrent or overvoltage; the voltage fluctuation locking unit triggers locking and suspends the tripping operation when it is detected that the voltage fluctuation exceeds the standard.

[0043] It will be obvious to a person skilled in the art that, without departing from the spirit or essential characteristics of the application, the present application can be implemented in other specific forms. The present examples are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the description given above, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claim.

Claims

1. A method for photovoltaic inverter operation control based on multi-source data, characterized in that, The method comprises the following steps: In the power collection circuit associated with the inverter, a main on-off circuit, a bypass circuit and a suppression circuit are built; multi-source data is collected to determine whether the photovoltaic power station has power generation conditions, and control instructions, including operation instructions and shutdown instructions, are generated; After the operation instruction is triggered, it is confirmed through detection equipment whether the current on the grid side and the inverter side is in a low load state, and the operation is delayed when the current exceeds the standard; an LSTM prediction model is used to control the closing of the vacuum contactor of the main on-off circuit, the suppression circuit is connected to the circuit, and the resistance is used to slow down the current rising rate at the moment of closing; After the current of the main circuit is stable, the optimal path is selected according to the orientation relationship between the main circuit and the bypass circuit and the photovoltaic power station, the bypass circuit is switched to run, and the suppression circuit is disconnected; the grid-connected voltage is monitored in real time, and when the voltage rises or drops suddenly, the closing rate of the main on-off circuit is adjusted; After the shutdown instruction is triggered, the main on-off circuit is controlled to open, the main connection between the power collection circuit and the inverter is cut off, and the bypass circuit remains running; after the main circuit is opened, the current and voltage states of the bypass circuit are detected, and after it is confirmed that there is no abnormal overcurrent or overvoltage, the bypass circuit is cut off; when the voltage fluctuation exceeds the standard, the lock is triggered, and the opening operation is suspended.

2. The method of claim 1, wherein, The main on-off circuit, the bypass circuit and the suppression circuit are built in the power collection circuit associated with the inverter, comprising: The main on-off circuit is responsible for the main control on-off of the power collection circuit operation and shutdown, the bypass circuit is responsible for the current shunt after the main circuit is stable, and the suppression circuit is responsible for suppressing the excitation inrush current and voltage fluctuation during operation; The main on-off circuit is connected in series between the inverter output end and the power collection circuit bus, forming a main current channel, and the isolation switch, the vacuum contactor and the current transformer are connected in series in the circuit, the voltage monitoring points are connected in parallel at both ends of the circuit, the voltage transformer is connected, and the voltage at both ends of the main circuit is monitored in real time; the bypass circuit is connected in parallel between the vacuum contactors of the main on-off circuit, forming a structure in parallel with the main on-off circuit and the bypass circuit, the bypass isolation switch, the bypass contactor and the current transformer are arranged in the circuit, and the bypass circuit is grouped according to the orientation of the photovoltaic array; the suppression circuit is connected in series between the vacuum contactor of the main on-off circuit and the power collection circuit bus, forming a series path, and the current limiting resistor and the suppression circuit contactor are arranged in the circuit, and the voltage monitoring points are connected in parallel at both ends of the suppression circuit to assist in judging the voltage division when the resistance is connected.

3. The method of claim 1, wherein, The multi-source data is collected to determine whether the photovoltaic power station has power generation conditions, and the control instructions, including operation instructions and shutdown instructions, are generated, comprising: The multi-source data includes photovoltaic component working condition data, grid access state data, environmental interference data and equipment health state data, and the effective threshold of each type of multi-source data is preset based on the design standard of the photovoltaic power station and the equipment parameters; the multi-source data is collected, data preprocessing is performed, the multi-source data is compared with the effective threshold, and when the components have power generation capacity, the grid has receiving capacity and the equipment has operation safety, the operation instruction is generated, otherwise the shutdown instruction is generated.

4. The method of claim 1, wherein, After the operation instruction is triggered, it is confirmed through detection equipment whether the current on the grid side and the inverter side is in a low load state, and the operation is delayed when the current exceeds the standard, comprising: The quantification threshold of the low load state is set based on the rated parameters of the inverter, the design standard of the current collection line and the excitation inrush current suppression target; the detection devices on the grid side and the inverter side are pre-calibrated; after the operation instruction is triggered, the collection of the grid side current and the inverter side current is triggered, and data preprocessing is performed; when the grid side current is not greater than the low load threshold and the inverter side current is not greater than the low load threshold, it is determined that the low load state is reached, otherwise the current is over-standard; when the current is over-standard, the main on-off circuit closing action is frozen, and an initial delay time is set; after the delay time is over, it is determined again whether the low load requirement is met, if the current is still over-standard, the verification process is repeated until the low current working condition requirement is met.

5. The method of claim 1, wherein, The vacuum contactor of the main on-off circuit is controlled to close by using the LSTM prediction model, and the suppression circuit is connected to the circuit to slow down the current rising rate at the closing moment by using a resistor, including: The time sequence data of the past closing process of the photovoltaic power station is collected to construct a training sample library, the time sequence features are input, including the grid side voltage sequence, the inverter side initial current sequence, the light intensity sequence, the component temperature sequence and the real-time temperature sequence of the suppression resistor, and the time sequence label is output, specifically the current rising sequence after closing; the data is cleaned and normalized, and divided into a training set and a validation set; the LSTM prediction model is constructed, the mean square error of the predicted current sequence and the actual sequence is minimized as the target, the Adam optimizer is used for training to ensure that the prediction error is within the allowable range; the current time sequence features are input into the LSTM model, and the prediction result is output, specifically the current rising curve, the predicted peak value, the predicted rising slope and the predicted magnetic core saturation time are extracted based on the curve to generate the control parameters of the closing and suppression circuits; based on the control parameters, the step closing instruction is sent to the vacuum contactor, and the early closing instruction is sent to the suppression circuit contactor.

6. The method of claim 1, wherein, After the main circuit current is stabilized, the optimal path is selected according to the orientation relationship of the main circuit and the bypass circuit with the photovoltaic power station, the bypass circuit is switched to run, and the suppression circuit is disconnected, including: The pre-stored power station topology data is called, which defines the physical connection relationship and electrical path of all bypass circuits and photovoltaic array groups, and the data attributes include circuit identification, associated array group, orientation coordinates and current state, the associated array group is a subset of photovoltaic arrays connected by the circuit, the orientation coordinates are the relative electrical distance between the circuit access point and the array group, and the current state is the state of the disconnecting switch and the contactor of the bypass circuit; The screening principle is set to select a bypass loop closest to the current main power generation array, real-time power generation data of each photovoltaic array group is obtained, one or more array groups that contribute to the main power generation are identified, and the identified main power generation array group is matched with the array group associated with each bypass loop; the path priority score of each bypass loop is calculated, and the score logic is that if the array group associated with a bypass loop overlaps with the current main power generation array group to the maximum extent, the score of the bypass loop is the highest; the bypass loop with the highest path priority score is selected as the target bypass loop for this switching, when multiple bypass loops with the same score appear, one with the shortest electrical path is selected; an operation blocking signal is sent to the vacuum contactor of the main on-off loop, the bypass disconnecting switch of the target bypass loop is closed, and then the bypass contactor of the loop is closed; when it is confirmed that the target bypass loop has stably carried the current and the main loop current starts to decrease and stabilizes at a threshold value, it is determined that the current transfer is successful; a trip command is sent to the suppression loop contactor to cut it out of the circuit; the operation blocking of the vacuum contactor of the main on-off loop is released.

7. The method of claim 1, wherein, The grid-connected voltage is monitored in real time, and when a voltage surge or drop trend occurs, the closing rate of the main on-off loop is adjusted, including: The grid point voltage value is sampled, linear regression analysis is performed on the collected voltage sequence in each analysis time window, the instantaneous slope and acceleration are calculated, a drop trend indicates that the instantaneous slope is negative and the absolute value exceeds a drop trend threshold, a surge trend indicates that the instantaneous slope is positive and the absolute value exceeds a rise trend threshold, and a stable state indicates that the absolute value of the instantaneous slope is below a threshold; when a drop trend is determined, the control target is to slow down the voltage drop rate and increase the voltage; when a surge trend is determined, the control target is to slow down the voltage rise rate and suppress the voltage.

8. The method for operating a photovoltaic inverter based on multi-source data according to claim 1, characterized in that, After the shutdown instruction is triggered, the main on-off loop is controlled to be tripped to cut off the main connection of the current collection line and the inverter, and the bypass loop remains running, including: A trip command is sent to the control unit of the main on-off loop to start the main connection cutting process, the bypass loop maintains the original running state, and the current is ensured to be continuously carried; during the tripping process, the action state of the main on-off loop is monitored in real time, it is confirmed that the contacts are gradually separated and the main connection of the current collection line and the inverter is gradually disconnected; when the main on-off loop feedbacks a tripping in-place signal and it is monitored that the main loop current has decreased to zero, it is determined that the main connection is successfully cut off; it is synchronously confirmed that the bypass loop still remains normal running, the current and voltage parameters are stable, and are not affected by the tripping of the main loop, the current operation is completed and the state is recorded.

9. The method for operating a photovoltaic inverter based on multi-source data according to claim 1, characterized in that, After the main loop is tripped, the current and voltage states of the bypass loop are detected, and after it is confirmed that there is no abnormal overcurrent or overvoltage, the bypass loop is cut off, including: After the main circuit is switched off, it is first confirmed that the current of the main circuit has dropped to zero and remains stable, and then the bypass circuit state detection process is started; the current and voltage of the bypass circuit are monitored in real time to determine whether there is abnormal overcurrent or abnormal overvoltage; if during continuous monitoring, the current and voltage of the bypass circuit are both within the normal range without any abnormal fluctuation, it is determined that the cut-off condition is met, and the cut-off operation is prepared to be performed; the bypass circuit cut-off program is started, and the cut-off speed is controlled according to the preset logic; after the cut-off action is completed, it is confirmed that the current of the bypass circuit has dropped to zero and the voltage has returned to a stable state, and it is determined that the cut-off is successful.

10. A multi-source data based photovoltaic inverter operation control system using the multi-source data based photovoltaic inverter operation control method of any one of claims 1-9, characterized in that, It comprises: a control instruction generation module, comprising: a circuit building unit and a control instruction generation unit; wherein, in the collector circuit associated with the inverter, the circuit building unit builds a main on-off circuit, a bypass circuit and a suppression circuit; the control instruction generation unit collects multi-source data, determines whether the photovoltaic power station has power generation conditions, generates control instructions, including commissioning instructions and shutdown instructions; a commissioning control module, comprising: a low-load state detection unit and an LSTM closing control unit; wherein, after the commissioning instruction is triggered, the low-load state detection unit confirms whether the current at the power grid side and the inverter side is in a low-load state through detection equipment, and delays commissioning when the current exceeds the standard; the LSTM closing control unit uses an LSTM prediction model to control the closing of the vacuum contactor of the main on-off circuit, connects the suppression circuit to the circuit, and uses resistance to slow down the current rise rate at the moment of closing; a circuit control module, comprising: a path optimization and switching unit and a voltage monitoring and adjustment unit; wherein, after the current of the main circuit is stable, the path optimization and switching unit selects the optimal path according to the positional relationship between the main circuit and the bypass circuit and the photovoltaic power station, switches to the bypass circuit operation, and disconnects the suppression circuit; the voltage monitoring and adjustment unit monitors the grid-connected voltage in real time, and adjusts the closing rate of the main on-off circuit when a voltage surge or a voltage drop trend occurs; a shutdown control module, comprising: a shutdown control unit, a bypass circuit cut-off control unit and a voltage fluctuation locking unit; wherein, after the shutdown instruction is triggered, the shutdown control unit controls the main on-off circuit to be switched off, disconnects the main connection between the collector circuit and the inverter, and keeps the bypass circuit running; after the main circuit is switched off, the bypass circuit cut-off control unit detects the current and voltage state of the bypass circuit, and cuts off the bypass circuit after confirming that there is no abnormal overcurrent or overvoltage; when the voltage fluctuation exceeds the standard is detected, the voltage fluctuation locking unit triggers the lock to suspend the switching-off operation.

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