Automatic Fast Response Method and System for Three-Phase Inverter in Off-Grid State

Abstract

Embodiments of the present application disclose an automatic fast response method and system for a three-phase inverter in an off-grid state. The method includes: real-time monitoring of the output control parameters of the three-phase inverter, and identifying the mutation situation of the load based on the detected output control parameters; in response to the mutation situation, determining the change type of the load and dynamically adjusting the output control parameters according to the change type and the current operating state, and maintaining the output control parameters within a preset stable range; according to the current change situation and historical change data of the load, predicting whether the output control parameters may oscillate within the next preset time period, and if so, generating a control increment for suppressing oscillation, and adjusting the output control parameters of the three-phase inverter to the preset stable range. The present application can optimize the performance of the three-phase inverter without grid support, enabling it to maintain stable output even when the load changes rapidly, and improving its power supply quality and system reliability.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of off-grid power supply of three-phase inverters, and particularly to an automatic and rapid response method and system for a three-phase inverter in an off-grid state. Background Art

[0002] When a three-phase inverter operates in an off-grid (island) state, due to the lack of grid support, it faces challenges in stability and response speed when the load changes. In the prior art, it is often difficult for an inverter to quickly adapt to sudden load changes in the off-grid state, resulting in output fluctuations and affecting the power supply quality. For example, when the load in an off-grid system suddenly increases, the inverter may not be able to immediately adjust the output, causing short-term instability of voltage and frequency and damaging sensitive devices. Summary of the Invention

[0003] The embodiments of the present application provide an automatic and rapid response method and system for a three-phase inverter in an off-grid state to optimize the performance of the three-phase inverter without grid support, so that it can maintain a stable output even when the load changes rapidly, and improve its power supply quality and system reliability.

[0004] In a first aspect, the embodiments of the present application provide an automatic and rapid response method for a three-phase inverter in an off-grid state, the method comprising the following steps:

[0005] During the operation of the load, the output control parameters of the three-phase inverter are monitored in real time, and the sudden change situation of the load is identified based on the detected output control parameters, where the output control parameters include any at least one of output current, output voltage, output power, and frequency;

[0006] In response to the sudden change situation, the change type of the load is determined and the output control parameters are dynamically adjusted according to the change type and the current operating state to maintain them within a preset stable range;

[0007] According to the current and historical change data of the output control parameters, it is predicted whether the output control parameters may oscillate within the next preset time period. If so, a control increment for suppressing the oscillation is generated through an incremental control model, and the output control parameters are adjusted to the preset stable range.

[0008] In some possible implementation manners, the following adaptive control model is used to calculate the dynamic adjustment amount of the output control parameters of the three-phase inverter:

[0009] Equation (1);

[0010] Equation (2);

[0011] Wherein, and represent the output power and the frequency adjustment amount at time respectively, and are the proportional and integral gains of the current loop, and are the proportional and integral gains of the voltage loop, and represent the current and voltage change amounts at time respectively.

[0012] In some possible implementation manners, the determining the change type of the load and dynamically adjusting the output control parameter according to the change type and the current operating state specifically includes:

[0013] If it is detected that the change value of the output control parameter exceeds a preset threshold, it is determined that a sudden change in the load occurs, and a type analysis of the load change is performed to distinguish whether it belongs to a sudden increase, a sudden decrease, or a slow change;

[0014] If the load change type is a sudden increase, the duty ratio of the inverter PWM control signal is increased according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power increases to a range matching the load change;

[0015] If the load change type is a sudden decrease, the duty ratio of the inverter PWM control signal is decreased according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power decreases to a range matching the load change;

[0016] If the load change type is a slow change, the duty ratio of the inverter PWM control signal is finely adjusted according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power is maintained in a range matching the load change;

[0017] And / or, the method further includes the following steps:

[0018] Determine whether there is an abnormality in the inverter output according to the monitored output control parameter, and determine the switching timing and the target operating mode of the three-phase inverter on the premise of avoiding or eliminating the abnormality.

[0019] In some possible implementation manners, the following optimization model is used to iteratively optimize the adaptive control model:

[0020] Equation (3);

[0021] Wherein, is the model parameter vector, is the actual output power, is the set output power, is a constraint condition, is a penalty factor; and / or

[0022] An anomaly detection model is also used to determine whether there is an anomaly in the inverter output:

[0023] Equation (4);

[0024] Wherein, is the monitoring data feature vector, is the weight, is the bias, represents a decision function for determining whether there is an anomaly.

[0025] In some possible implementation manners, the following prediction model is used to predict whether the output control parameter may oscillate in the next preset time period:

[0026] Equation (5);

[0027] Wherein, is the predicted future state, is the current state, is the current control input, and are the system state space model matrices, is the predictive control matrix, is the control increment;

[0028] The following incremental control model is used to generate the control increment:

[0029] Equation (6);

[0030] Wherein, is the desired system state, is the weight factor, which is used to balance the state tracking and the smoothness of the input control quantity.

[0031] In a second aspect, an embodiment of the present application provides an automatic fast response system for a three-phase inverter in an off-grid state. The system includes:

[0032] A load change recognition unit, configured to, during the operation of the load, monitor the output control parameters of the three-phase inverter in real time, and identify the mutation situation of the load based on the detected output control parameters. The output control parameters include any at least one of output current, output voltage, output power, and frequency;

[0033] A load change response unit, configured to determine a type of load change in response to the mutation situation and dynamically adjust the output control parameter according to the change type and the current operating state, so as to maintain it within a preset stable range;

[0034] An oscillation prediction and suppression unit, configured to predict whether the output control parameter may oscillate within the next preset time period according to current and historical change data of the output control parameter, and if so, generate a control increment for suppressing the oscillation through an incremental control model, and adjust the output control parameter to the preset stable range.

[0035] In some possible implementation manners, the load change response unit calculates a dynamic adjustment amount of the output control parameter of the three-phase inverter by using the following adaptive control model:

[0036] Equation (1);

[0037] Equation (2);

[0038] Wherein, and respectively represent the output power and the frequency adjustment amount at time ; and are the proportional and integral gains of the current loop; and are the proportional and integral gains of the voltage loop; and respectively represent the current and voltage change amounts at time ;

[0039] In some possible implementation manners, the load change response unit specifically includes:

[0040] A change type identification unit, configured to determine that a load mutation has occurred if a change value of the output control parameter exceeds a preset threshold, and perform type analysis on the load change to distinguish whether it belongs to a sudden increase, a sudden decrease or a slow change;

[0041] An output power adjustment unit, configured to increase the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model if the load change type is a sudden increase, so that its output power increases to a range matching the load change;

[0042] If the load change type is a sudden decrease, reduce the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power decreases to a range matching the load change;

[0043] If the load change type is slow change, the duty cycle of the inverter PWM control signal is finely adjusted according to the dynamic adjustment amount calculated by the adaptive control model, so that the output power is maintained within a range matching the load change;

[0044] And / or, the system further includes:

[0045] A working mode switching unit, configured to determine whether there is an abnormality in the inverter output according to the monitored output control parameters, and determine the switching timing and target working mode of the three-phase inverter on the premise of avoiding or eliminating the abnormality.

[0046] In some possible implementation manners, the load change response unit further iteratively optimizes the adaptive control model by using the following optimization model:

[0047] Equation (3);

[0048] Wherein, is the model parameter vector, is the actual output power, is the set output power, is the constraint condition, is the penalty factor; and / or

[0049] The working mode switching unit determines whether there is an abnormality in the inverter output by using the following abnormality detection model:

[0050] Equation (4);

[0051] Wherein, is the monitoring data feature vector, is the weight, is the bias, represents the decision function for judging whether there is an abnormality.

[0052] In some possible implementation manners, the oscillation prediction and suppression unit predicts whether the output control parameters may oscillate in the next preset time period by using the following prediction model:

[0053] Equation (5);

[0054] Wherein, is the predicted future state, is the current state, is the current control input, and are the system state space model matrices, is the predictive control matrix, is the control increment;

[0055] The control increment is generated by using the following incremental control model:

[0056] Equation (6);

[0057] wherein, is the desired system state, is the weight factor, which is used to balance the state tracking and the smoothness of the input control quantity.

[0058] The beneficial effects of the present application are as follows:

[0059] In the embodiment of the present application, during the operation of the load, the output control parameters of the three-phase inverter are monitored in real time, and the mutation situation of the load is identified based on the detected output control parameters. The output control parameters are dynamically adjusted according to the change type of the load and the current operation state to maintain them within a preset stable range; and according to the current and historical change data of the output control parameters, it is predicted whether the output control parameters will oscillate within the next preset time period. If so, a control increment for suppressing the oscillation is generated, and the output control parameters are adjusted to the preset stable range, thereby significantly optimizing the performance of the three-phase inverter without grid support, ensuring that the three-phase inverter in the off-grid state can maintain stable output even when the load changes rapidly, and greatly improving its power supply quality and system reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0061] Figure 1 is a schematic flow chart of the automatic fast response method of the three-phase inverter in the off-grid state in the embodiment of the present application.

[0062] Figure 2 is a schematic structural diagram of the automatic fast response system of the three-phase inverter in the off-grid state in the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the following will describe the technical solutions of this application in detail through implementation manners with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Without conflict, the embodiments and features in the embodiments of this application can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application.

[0064] It should be noted that in the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end; in the description of this application, terms such as "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation on the protection scope of this application; in the description of this application, "first", "second", etc. are only used for distinction from each other, rather than indicating their importance level and sequence, etc.

[0065] In the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a movable connection, or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements, etc. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0066] Please refer to Figure 1 , the embodiments of this application provide an automatic and rapid response method for a three-phase inverter in an off-grid state. The method includes the following steps:

[0067] In step S1, during the operation of the load, the output control parameters of the three-phase inverter are monitored in real time, and based on the detected output control parameters, the mutation situation of the load is identified. The output control parameters include any at least one of output current, output voltage, output power, and frequency;

[0068] In step S2, in response to the mutation situation, the change type of the load is determined, and the output control parameters are dynamically adjusted according to the change type and the current operating state to maintain them within a preset stable range;

[0069] In step S3, based on the current and historical change data of the output control parameter, it is predicted whether the output control parameter may oscillate within the next preset time period. If so, a control increment for suppressing the oscillation is generated through an incremental control model, and the output control parameter is adjusted to a preset stable range.

[0070] In some possible implementation manners, the following adaptive control model is used to calculate the dynamic adjustment amount of the output control parameter of the three-phase inverter:

[0071] Equation (1);

[0072] Equation (2);

[0073] Wherein, and respectively represent the output power and the frequency adjustment amount at time , and are the proportional and integral gains of the current loop, and are the proportional and integral gains of the voltage loop, and respectively represent the current and voltage change amounts at time .

[0074] In some possible implementation manners, the determining the change type of the load and dynamically adjusting the output control parameter according to the change type and the current operating state specifically includes:

[0075] If it is detected that the change value of the output control parameter exceeds a preset threshold, it is determined that the load has undergone a sudden change, and a type analysis of the load change is performed to distinguish whether it belongs to a sudden increase, a sudden decrease, or a slow change;

[0076] If the load change type is a sudden increase, the duty ratio of the inverter PWM control signal is increased according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power increases to a range matching the load change;

[0077] If the load change type is a sudden decrease, the duty ratio of the inverter PWM control signal is decreased according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power decreases to a range matching the load change;

[0078] If the load change type is a slow change, the duty ratio of the inverter PWM control signal is finely adjusted according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power is maintained in a range matching the load change;

[0079] And / or, the method further includes the following steps:

[0080] Determine whether there is an abnormality in the output of the inverter according to the monitored output control parameters, and determine the switching timing and target operating mode of the three-phase inverter on the premise of avoiding or eliminating the abnormality.

[0081] In some possible implementation manners, the following optimization model is used to iteratively optimize the adaptive control model:

[0082] Equation (3);

[0083] Wherein, is the model parameter vector, is the actual output power, is the set output power, is the constraint condition, is the penalty factor; and / or

[0084] The following anomaly detection model is also used to determine whether there is an abnormality in the output of the inverter:

[0085] Equation (4);

[0086] Wherein, is the monitoring data feature vector, is the weight, is the bias, represents the decision function for judging whether there is an abnormality.

[0087] In some possible implementation manners, the following prediction model is used to predict whether the output control parameters may oscillate in the next preset time period:

[0088] Equation (5);

[0089] Wherein, is the predicted future state, is the current state, is the current control input, and are the system state space model matrices, is the predictive control matrix, is the control increment;

[0090] The following incremental control model is used to generate the control increment:

[0091] Equation (6);

[0092] Wherein, is the desired system state, is a weight factor used to balance the smoothness of state tracking and input control quantity.

[0093] Please refer to Figure 2 , based on the above embodiments, the embodiments of the present application further provide an automatic fast response system for a three-phase inverter in an off-grid state, and the system includes:

[0094] A load change recognition unit 1, configured to, during the operation of the load, monitor in real time the output control parameters of the three-phase inverter, and identify the mutation situation of the load based on the detected output control parameters, where the output control parameters include any at least one of output current, output voltage, output power, and frequency;

[0095] A load change response unit 2, configured to, in response to the mutation situation, determine the change type of the load and dynamically adjust the output control parameters according to the change type and the current operation state so that they are maintained within a preset stable range;

[0096] An oscillation prediction and suppression unit 3, configured to, according to the current and historical change data of the output control parameters, predict whether the output control parameters may oscillate within the next preset time period, and if so, generate a control increment for suppressing the oscillation through an incremental control model, and adjust the output control parameters to the preset stable range.

[0097] In some possible implementation manners, the load change response unit calculates the dynamic adjustment amount of the output control parameters of the three-phase inverter by using the following adaptive control model:

[0098] Equation (1);

[0099] Equation (2);

[0100] Wherein, and respectively represent the output power and frequency adjustment amounts at time , and are the proportional and integral gains of the current loop, and are the proportional and integral gains of the voltage loop, and respectively represent the current and voltage change amounts at time .

[0101] In some possible implementation manners, the load change response unit specifically includes:

[0102] The change type recognition unit 21 is configured to determine that a load mutation has occurred when it detects that the change value of the output control parameter exceeds a preset threshold, analyze the type of the load change, and distinguish whether it belongs to a sudden increase, a sudden decrease, or a slow change;

[0103] The output power adjustment unit 22 is configured to, if the load change type is a sudden increase, increase the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power increases to a range matching the load change;

[0104] If the load change type is a sudden decrease, decrease the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power decreases to a range matching the load change;

[0105] If the load change type is a slow change, finely adjust the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power is maintained in a range matching the load change;

[0106] And / or, the system further includes:

[0107] The working mode switching unit 4 is configured to determine whether there is an abnormality in the inverter output according to the monitored output control parameter, and determine the switching timing and the target working mode of the three-phase inverter on the premise of avoiding or eliminating the abnormality.

[0108] In some possible implementation manners, the load change response unit further iteratively optimizes the adaptive control model by using the following optimization model:

[0109] Equation (3);

[0110] Wherein, is the model parameter vector, is the actual output power, is the set output power, is the constraint condition, is the penalty factor; and / or

[0111] The working mode switching unit determines whether there is an abnormality in the inverter output by using the following abnormality detection model:

[0112] Equation (4);

[0113] Wherein, is the monitoring data feature vector, is the weight, is the bias, represents the decision function for judging whether there is an abnormality.

[0114] In some possible embodiments, the oscillation prediction and suppression unit uses the following prediction model to predict whether the output control parameter may oscillate within the next preset time period:

[0115] Equation (5);

[0116] Wherein, is the predicted future state, is the current state, is the current control input, and are the system state space model matrices, is the predictive control matrix, is the control increment;

[0117] The following incremental control model is used to generate the control increment:

[0118] Equation (6);

[0119] Wherein, is the desired system state, is the weight factor, which is used to balance the state tracking and the smoothness of the input control quantity.

[0120] In order to improve the fast response ability of the three-phase inverter to load changes in the off-grid state as much as possible, a high-precision current transformer (CT) and a voltage sensor can be used to collect the current and voltage signals of the load in real time. The fast detection of load mutation can be achieved through the following steps:

[0121] Signal acquisition: The current transformer is used to non-contact monitor the load current at the output end of the three-phase inverter, and at the same time, the voltage sensor synchronously collects the output voltage signal.

[0122] Signal processing: After the collected current and voltage analog signals are filtered by the filter circuit to remove high-frequency noise, they are converted into digital signals through an analog-to-digital converter (ADC).

[0123] Mutation detection algorithm: Apply the differential detection algorithm model to the converted digital signal, compare the difference between the current sampling value and the historical sampling value in real time, and if the difference exceeds the preset threshold, it is determined that the load has mutated.

[0124] The differential detection algorithm model is as follows:

[0125]

[0126]

[0127] Wherein, and respectively represent the time current and voltage change amounts, and respectively represent the real-time current and voltage values at time

[0128] Dynamic threshold adjustment: Dynamically adjust the detection threshold according to historical data to adapt to load changes under different working conditions.

[0129] The following uses a specific example to illustrate the above process.

[0130] Suppose a three-phase inverter operates in an off-grid state, supplying a constant load. The system sets the threshold of the current change amount to and the threshold of the voltage change amount to .

[0131] After the system is initialized, it starts to collect current and voltage signals in real time.

[0132] After filtering and analog-to-digital conversion, assume that at a certain moment , the current suddenly increases from to , and the voltage remains unchanged.

[0133] According to the mutation detection algorithm, it is calculated that , exceeding the preset current change threshold .

[0134] Therefore, the system determines that there is a load mutation and triggers subsequent load change responses to quickly adapt to the new load conditions.

[0135] By implementing the steps in the above fast detection strategy for load mutation, it is possible to quickly respond to load changes without grid support and ensure the stable operation of the inverter.

[0136] Suppose in the off-grid state, due to a sudden increase in the load, the system detects that the current change amount exceeds the preset threshold. After detecting the load change, the output control parameters of the three-phase inverter can be dynamically adjusted through the following steps in combination with the above adaptive control model to ensure the stability of the output voltage and frequency:

[0137] Load change analysis: First, analyze the type of the detected load change to distinguish whether it is a sudden increase, a sudden decrease, or a slow change, so as to determine the control strategy.

[0138] Adaptive control algorithm: According to the type of load change and the current operating state of the system, use the above adaptive control model to calculate the dynamic adjustment amounts of the output power and frequency, and dynamically adjust the switching strategy and PWM modulation signal of the inverter to meet the load demand and maintain the stability of the output voltage and frequency.

[0139] PWM signal adjustment: According to the dynamic adjustment amounts calculated by the above algorithm, dynamically adjust the duty cycle of the PWM signal, thereby changing the output voltage and frequency of the inverter.

[0140] By implementing the above steps for dynamically adjusting the output control parameters of the three-phase inverter, continuously adjusting the PWM duty cycle through closed-loop control to maintain the long-term stability of the output voltage and frequency, it can effectively cope with load changes in the off-grid state and ensure the stability of the output performance of the three-phase inverter.

[0141] In the off-grid state, in order to maintain the stability of the system and avoid output fluctuations caused by load changes or external disturbances, the prediction control strategy and optimization algorithm can be combined, and the system stability maintenance can be implemented through the following steps:

[0142] Prediction control strategy: Use historical data and real-time monitoring information to predict the dynamic behavior of the system in the future for a period of time. The possible oscillation modes and their development trajectories can be predicted through the above prediction model.

[0143] Optimization algorithm: Combining the prediction results, use the control increment calculated by the above incremental control model to adjust the control strategy to suppress the predicted oscillation and achieve the optimization goal of minimizing the output fluctuation and system response time.

[0144] Control instruction generation: According to the optimization results, generate corresponding control instructions to adjust the switching state and PWM signal of the inverter to achieve stability maintenance.

[0145] By implementing the above steps in the system stability maintenance, it can effectively predict and suppress system oscillation in the off-grid state, enhance the anti-interference ability of the system, and thus improve the performance of the three-phase inverter without grid support.

[0146] In order to achieve the rapid switching of the three-phase inverter between different working modes and reduce the energy loss during the switching process, the intelligent detection and optimized switching logic can be combined, and the rapid switching mechanism can be implemented through the following steps:

[0147] 1) Intelligent identification:

[0148] Real-time monitoring: Real-time monitor the key parameters of the three-phase inverter (such as output voltage, current, frequency, etc.).

[0149] Anomaly Detection: Adopt anomaly detection technology based on machine learning algorithms to quickly identify abnormal conditions that may lead to work mode switching through the above anomaly detection model.

[0150] 2) Optimization of Switching Logic:

[0151] Decision-making Logic: Design decision-making logic based on the output of the intelligent detection module to determine the switching timing and target work mode.

[0152] Dynamic Weight Adjustment: Introduce a dynamic weight adjustment mechanism to optimize the switching logic according to the current working state and load demand.

[0153] 3) Fast Switching Circuit Design:

[0154] Switching Elements: Adopt high-speed and low-loss switching elements to reduce energy loss during the switching process.

[0155] Synchronization Control: Design a synchronization control circuit to ensure seamless energy connection of the inverter during the switching process.

[0156] 4) Switching Process Control:

[0157] Soft Start / Soft Stop: Adopt soft start and soft stop technologies during the switching process for smooth transition and reduced impact.

[0158] PWM Modulation Strategy: Optimize the PWM modulation strategy to adjust the pulse width during switching and reduce output fluctuations.

[0159] 5) Switching Performance Evaluation:

[0160] Evaluation Metrics: Define performance evaluation metrics such as switching time and energy loss.

[0161] Feedback Adjustment: According to the performance evaluation results, feedback and adjust the switching logic and circuit parameters.

[0162] By implementing each step in the above fast switching mechanism, it is possible to minimize energy loss while ensuring the switching speed and improve the overall performance of the three-phase inverter in the off-grid state.

[0163] To improve the overall performance and energy efficiency of the three-phase inverter in the off-grid state, a performance optimization strategy based on real-time data analysis can also be adopted. The output control parameters of the three-phase inverter are dynamically adjusted through the following steps to adapt to changing load conditions and environmental factors, and improve the overall performance and energy efficiency of the inverter in the off-grid state:

[0164] 1) Real-time Data Analysis:

[0165] Data Acquisition: High-precision acquisition of key parameters such as the output voltage, current, and power factor of the inverter.

[0166] Data processing: Filter, analyze, and extract features from the collected data using digital signal processing techniques.

[0167] 2) Control strategy optimization:

[0168] Model establishment: Establish a mathematical model of the inverter output performance based on the collected data.

[0169] Parameter optimization: Iteratively optimize the parameters of the above adaptive control model using the above optimization models (such as particle swarm optimization or genetic algorithm).

[0170] 3) Dynamic parameter adjustment:

[0171] Adaptive control: According to the real-time data analysis results, adaptively adjust the operating point of the inverter to achieve the best performance.

[0172] Feedback mechanism: Establish a feedback mechanism to monitor the output performance in real time and adjust the control parameters in a timely manner.

[0173] 4) Performance evaluation:

[0174] Evaluation metrics: Define performance evaluation metrics including efficiency, stability, response time, etc.

[0175] Continuous improvement: According to the performance evaluation results, continuously adjust and optimize the algorithm, and through continuous data analysis and parameter adjustment, achieve the performance optimization of the inverter in the off-grid state.

[0176] By implementing each step in the above performance optimization strategy, it can be ensured that the inverter in the off-grid state can not only quickly respond to load changes, but also improve the energy conversion efficiency while ensuring stable output, achieving a double improvement in performance and energy efficiency.

[0177] The embodiments of the present application can significantly optimize the performance of the three-phase inverter without grid support, enabling it to maintain stable output even when the load changes rapidly, and improving its power supply quality and system reliability.

[0178] Those skilled in the art should be able to realize that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented by hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. The computer-readable medium includes computer storage media and communication media, where the communication media includes any medium that facilitates the transmission of a computer program from one place to another. The storage media can be any available medium accessible by a general-purpose or special-purpose computer.

[0179] Note that the above is only the preferred embodiment of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments only. Without departing from the concept of the present application, more other equivalent embodiments can be included, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. An automatic rapid response method for a three-phase inverter in an off-grid state, characterized in that: The method comprises the following steps: During the operation of the load, the output control parameters of the three-phase inverter are monitored in real time, and the sudden change of the load is identified based on the detected output control parameters, wherein the output control parameters include any at least one of output current, output voltage, output power, and frequency; In response to the sudden change, determining the type of load change and dynamically adjusting the output control parameter according to the type of change and the current operating state to maintain it within a preset stable range; According to the current and historical change data of the output control parameter, predict whether the output control parameter will oscillate in the next preset time period, and if so, generate a control increment for suppressing the oscillation, and adjust the output control parameter to a preset stable range; The following prediction model is used to predict whether the output control parameter may oscillate in the next preset time period: Formula (5); in, is the predicted future state, is the current state, is the current control input, and is the system state space model matrix, is the predictive control matrix, It is the control increment; The control increment is calculated using the following increment control model: Formula (6); in, is the desired system state, is a weight factor used to balance the smoothness of state tracking and input control quantity.

2. The method according to claim 1, characterized in that The following adaptive control model is used to calculate the dynamic adjustment amount of the output control parameter of the three-phase inverter: Formula (1); Formula (2); in, and Represents time The output power and frequency adjustment amount, and are the proportional and integral gains of the current loop, and are the proportional and integral gains of the voltage loop, and Represents time The current and voltage changes.

3. The method according to claim 2, characterized in that Determining the load change type and dynamically adjusting the output control parameter according to the change type and the current operating state specifically includes: If it is detected that the change value of the output control parameter exceeds a preset threshold, it is determined that a sudden change has occurred in the load, and a type analysis is performed on the load change to distinguish whether it is a sudden increase, a sudden decrease or a slow change; If the load change type is a sudden increase, the duty cycle of the inverter PWM control signal is increased according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power increases to a range matching the load change; If the load change type is a sudden decrease, the duty cycle of the inverter PWM control signal is reduced according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power is reduced to a range matching the load change; If the load change type is a slow change, the duty cycle of the inverter PWM control signal is fine-tuned according to the dynamic adjustment amount calculated by the adaptive control model so that its output power is maintained within a range matching the load change; And / or, the method further comprises the following steps: It is determined whether there is an abnormality in the inverter output according to the monitored output control parameters, and the switching timing and target working mode of the three-phase inverter are determined on the premise of avoiding or eliminating the abnormality.

4. The method according to claim 3, characterized in that The following optimization model is also used to iteratively optimize the adaptive control model: Formula (3); in, is the model parameter vector, is the actual output power, is to set the output power, is a constraint, is a penalty factor; and / or The following abnormality detection model is used to determine whether there is an abnormality in the inverter output: Formula (4); in, is the monitoring data feature vector, is the weight, is the bias, Represents the decision function for determining whether an anomaly exists.

5. An automatic rapid response system for a three-phase inverter in an off-grid state, characterized in that: The system comprises: A load change identification unit, used to monitor the output control parameters of the three-phase inverter in real time during the load operation, and identify the sudden change of the load based on the detected output control parameters, wherein the output control parameters include any at least one of output current, output voltage, output power and frequency; A load change response unit, for responding to the mutation, determining the type of load change and dynamically adjusting the output control parameter according to the type of change and the current operating state, so as to maintain it within a preset stable range; An oscillation prediction and suppression unit, used to predict whether the output control parameter is likely to oscillate within a next preset time period based on the current and historical change data of the output control parameter, and if so, to generate a control increment for suppressing the oscillation through an incremental control model, and adjust the output control parameter to a preset stable range; The oscillation prediction and suppression unit uses the following prediction model to predict whether the output control parameter is likely to oscillate within the next preset time period: Formula (5); in, is the predicted future state, is the current state, is the current control input, and is the system state space model matrix, is the predictive control matrix, It is the control increment; The control increment is calculated using the following increment control model: Formula (6); in, is the desired system state, is a weight factor used to balance the smoothness of state tracking and input control quantity.

6. The system according to claim 5, characterized in that The load change response unit uses the following adaptive control model to calculate the dynamic adjustment amount of the output control parameter of the three-phase inverter: Formula (1); Formula (2); in, and Represents time The output power and frequency adjustment amount, and are the proportional and integral gains of the current loop, and are the proportional and integral gains of the voltage loop, and Represents time The current and voltage changes.

7. The system according to claim 6, characterized in that The load change response unit specifically includes: A change type identification unit is used to detect that the change value of the output control parameter exceeds a preset threshold, then determine that the load has undergone a sudden change, and perform a type analysis on the load change to distinguish whether it is a sudden increase, a sudden decrease or a slow change; An output power adjustment unit, configured to increase the duty cycle of the inverter PWM control signal according to the dynamic adjustment amount calculated by the adaptive control model if the load change type is a sudden increase, so that the output power thereof is increased to a range matching the load change; If the load change type is a sudden decrease, the duty cycle of the inverter PWM control signal is reduced according to the dynamic adjustment amount calculated by the adaptive control model, so that its output power is reduced to a range matching the load change; If the load change type is a slow change, the duty cycle of the inverter PWM control signal is fine-tuned according to the dynamic adjustment amount calculated by the adaptive control model so that its output power is maintained within a range matching the load change; And / or, the system further comprises: The working mode switching unit is used to determine whether there is an abnormality in the inverter output according to the monitored output control parameters, and determine the switching timing and target working mode of the three-phase inverter on the premise of avoiding or eliminating the abnormality.

8. The system according to claim 7, characterized in that The load change response unit also uses the following optimization model to iteratively optimize the adaptive control model: Formula (3); in, is the model parameter vector, is the actual output power, is to set the output power, is a constraint, is a penalty factor; and / or The working mode switching unit uses the following abnormality detection model to determine whether there is an abnormality in the inverter output: Formula (4); in, is the monitoring data feature vector, is the weight, is the bias, Represents the decision function for determining whether an anomaly exists.

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