Automatic quick response method and system for three-phase inverter in off-grid state

Abstract

The embodiment of the invention discloses an automatic quick response method and system for a three-phase inverter in an off-grid state, and the method comprises the steps: monitoring an output control parameter of the three-phase inverter in real time, and recognizing a sudden change condition of a load based on the detected output control parameter; in response to the sudden change condition, determining the change type of the load, dynamically adjusting the output control parameter according to the change type and the current operation state, and maintaining the output control parameter in a preset stable range; and according to the current change condition and the historical change data of the load, predicting whether the output control parameter may generate oscillation in the next preset time period, if so, generating a control increment for suppressing oscillation, and adjusting the output control parameter of the three-phase inverter to a preset stable range. According to the invention, the performance of the three-phase inverter without the support of a power grid can be optimized, so that the three-phase inverter can maintain stable output even if the load changes rapidly, and the power supply quality and the system reliability are improved.

Description

Technical Field

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

[0002] When three-phase inverters are operating in an off-grid (island) state, they face challenges in stability and response speed when the load changes due to the lack of grid support. In the existing technology, it is often difficult for inverters to quickly adapt to sudden load changes in an 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 adjust the output immediately, causing short-term instability in voltage and frequency, and causing damage to sensitive equipment. Summary of the invention

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

[0004] In a first aspect, an embodiment of the present application provides an automatic rapid response method for a three-phase inverter in an off-grid state, the method comprising 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; Based on the current and historical change data of the output control parameter, it is predicted whether the output control parameter is likely to oscillate within the next preset time period. If so, a control increment for suppressing the oscillation is generated through an incremental control model to adjust the output control parameter to a preset stable range.

[0005] In some possible implementations, 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.

[0006] In some possible implementations, 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 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, fine-tuning 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 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.

[0007] In some possible implementations, the adaptive control model is iteratively optimized using the following optimization 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 also 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.

[0008] In some possible implementations, the following prediction model is used 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 generated 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.

[0009] In a second aspect, an embodiment of the present application provides an automatic rapid response system for a three-phase inverter in an off-grid state, the system comprising: 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; The oscillation prediction and suppression unit is used to predict whether the output control parameter is likely to oscillate within the next preset time period based on the current and historical change data of the output control parameter. If so, a control increment for suppressing the oscillation is generated through an incremental control model to adjust the output control parameter to a preset stable range.

[0010] In some possible implementations, 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.

[0011] In some possible implementations, the load change response unit specifically includes: a change type identification unit, configured to detect that a change value of the output control parameter exceeds a preset threshold, determine that a sudden change has occurred in the load, 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, fine-tuning 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 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.

[0012] In some possible implementations, the load change response unit further 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.

[0013] In some possible implementations, 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 generated 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.

[0014] The beneficial effects of this application are: The embodiment of the present application monitors the output control parameters of the three-phase inverter in real time during the operation of the load, identifies sudden changes in the load based on the detected output control parameters, and dynamically adjusts the output control parameters according to the type of load change and the current operating state to maintain them within a preset stable range; and predicts whether the output control parameters will oscillate within the next preset time period based on the current and historical change data of the output control parameters. If so, a control increment is generated to suppress the oscillation, and the output control parameters are adjusted to a preset stable range, thereby significantly optimizing the performance of the three-phase inverter without grid support, ensuring that the three-phase inverter in an 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

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a flow chart of the automatic rapid response method of the three-phase inverter in the off-grid state according to an embodiment of the present application.

[0017] Figure 2 It is a structural schematic diagram of the automatic rapid response system of the three-phase inverter in the off-grid state according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail by way of implementation methods with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0019] It should be noted that: in the accompanying drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions; in the description of the present application, the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; in the description of the present application, "first", "second", etc. are only used to distinguish each other, rather than to indicate their importance and order, etc.

[0020] 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal communication of two components, etc. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0021] Please refer to Figure 1 The embodiment of the present application provides an automatic rapid response method of a three-phase inverter in an off-grid state, the method comprising the following steps: In step S1, 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 step S2, in response to the sudden change, the load change type is determined and the output control parameter is dynamically adjusted according to the change type and the current operating state to maintain it within a preset stable range; In step S3, based on the current and historical change data of the output control parameter, it is predicted whether the output control parameter is likely to oscillate within the next preset time period. If so, a control increment for suppressing the oscillation is generated through an incremental control model to adjust the output control parameter to a preset stable range.

[0022] In some possible implementations, 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.

[0023] In some possible implementations, 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 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, fine-tuning 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 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.

[0024] In some possible implementations, the adaptive control model is iteratively optimized using the following optimization 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 also 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.

[0025] In some possible implementations, the following prediction model is used 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 generated 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.

[0026] Please refer to Figure 2 Based on the above embodiments, the present application also provides an automatic rapid response system for a three-phase inverter in an off-grid state, the system comprising: A load change identification unit 1 is 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 2, for determining the load change type in response to the sudden change and dynamically adjusting the output control parameter according to the change type and the current operating state to maintain it within a preset stable range; The oscillation prediction and suppression unit 3 is used to predict whether the output control parameter is likely to oscillate within the next preset time period based on the current and historical change data of the output control parameter. If so, a control increment for suppressing the oscillation is generated through an incremental control model to adjust the output control parameter to a preset stable range.

[0027] In some possible implementations, 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.

[0028] In some possible implementations, the load change response unit specifically includes: The change type identification unit 21 is used to detect that the change value of the output control parameter exceeds a preset threshold, 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 22, 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 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, fine-tuning 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 within a range matching the load change; And / or, the system further comprises: The working mode switching unit 4 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.

[0029] In some possible implementations, the load change response unit further 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.

[0030] In some possible implementations, 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 generated 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.

[0031] In order to improve the three-phase inverter's ability to respond quickly to load changes when off-grid, high-precision current transformers (CTs) and voltage sensors can be used to collect the load's current and voltage signals in real time. The following steps can be used to quickly detect sudden load changes: Signal acquisition: The load current at the output of the three-phase inverter is monitored contactlessly using a current transformer, while the voltage sensor synchronously acquires the output voltage signal.

[0032] Signal processing: The collected current and voltage analog signals are filtered to remove high-frequency noise and then converted into digital signals through an analog-to-digital converter (ADC).

[0033] Mutation detection algorithm: A differential detection algorithm model is applied to the converted digital signal to compare the difference between the current sampling value and the historical sampling value in real time. If the difference exceeds the preset threshold, it is determined to be a load mutation.

[0034] The differential detection algorithm model is as follows:

[0035]

[0036] in, and Represents time The current and voltage changes, and Represents time Real-time current and voltage values.

[0037] Dynamic threshold adjustment: Dynamically adjust the detection threshold based on historical data to adapt to load changes under different working conditions.

[0038] The above process is illustrated below with a specific example.

[0039] Assume that the three-phase inverter is operating in an off-grid state, supplying power to a constant load. The threshold value of the current change is set as , the voltage change threshold is .

[0040] After the system is initialized, it starts to collect current and voltage signals in real time.

[0041] After filtering and analog-to-digital conversion, assuming that at a certain moment , the current from Increased to ,Voltage Remain unchanged.

[0042] According to the mutation detection algorithm, we can calculate , exceeds the preset current change threshold .

[0043] Therefore, the system determines it as a sudden load change and triggers subsequent load change responses to quickly adapt to the new load conditions.

[0044] By implementing the steps in the above-mentioned rapid detection strategy for load mutation, it is possible to respond quickly to load changes without grid support to ensure stable operation of the inverter.

[0045] Assume that in the off-grid state, due to a sudden increase in load, the system detects that the current change 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: Load change analysis: First, analyze the type of load change detected to distinguish whether it is a sudden increase, a sudden decrease, or a slow change, so as to determine the control strategy.

[0046] Adaptive control algorithm: According to the load change type and the current operating status of the system, the above adaptive control model is used to calculate the dynamic adjustment of 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 output voltage and frequency.

[0047] PWM signal adjustment: According to the dynamic adjustment amount calculated by the above algorithm, the duty cycle of the PWM signal is dynamically adjusted to change the output voltage and frequency of the inverter.

[0048] By implementing the above steps of dynamically adjusting the output control parameters of the three-phase inverter, the PWM duty cycle is continuously adjusted through closed-loop control to maintain the long-term stability of the output voltage and frequency, which can effectively cope with load changes in the off-grid state and ensure the stability of the output performance of the three-phase inverter.

[0049] In the off-grid state, in order to maintain the stability of the system and avoid output fluctuations caused by load changes or external interference, the predictive control strategy and optimization algorithm can be combined to implement system stability maintenance through the following steps: Predictive control strategy: Use historical data and real-time monitoring information to predict the dynamic behavior of the system in the future. The above prediction model can be used to predict possible oscillation patterns and their development trajectories.

[0050] Optimization algorithm: Combined with the prediction results, the control increment calculated by the above incremental control model is used to adjust the control strategy to suppress the predicted oscillation and achieve the optimization goal of minimizing output fluctuations and system response time.

[0051] Control instruction generation: Based on the optimization results, corresponding control instructions are generated to adjust the switching state and PWM signal of the inverter to achieve stability maintenance.

[0052] By implementing the above steps in system stability maintenance, system oscillation can be effectively predicted and suppressed in an off-grid state, and the system's anti-interference ability can be enhanced, thereby improving the performance of the three-phase inverter when there is no grid support.

[0053] In order to achieve fast switching of the three-phase inverter between different working modes and reduce energy loss during the switching process, the fast switching mechanism can be implemented by combining intelligent detection and optimized switching logic through the following steps: 1) Intelligent identification: Real-time monitoring: Real-time monitoring of key parameters of three-phase inverters (such as output voltage, current, frequency, etc.).

[0054] Anomaly detection: Use anomaly detection technology based on machine learning algorithms to quickly identify abnormal conditions that may cause working mode switching through the above anomaly detection model.

[0055] 2) Optimize switching logic: Decision logic: Design decision logic based on the output of the intelligent detection module to determine the switching timing and target working mode.

[0056] Dynamic weight adjustment: Introduce a dynamic weight adjustment mechanism to optimize the switching logic based on the current working status and load requirements.

[0057] 3) Fast switching circuit design: Switching elements: Use high-speed, low-loss switching elements to reduce energy loss during switching.

[0058] Synchronous control: Design synchronous control circuit to ensure seamless energy connection of inverter during switching process.

[0059] 4) Switching process control: Soft start / soft stop: Soft start and soft stop technology are used during the switching process to ensure smooth transition and reduce impact.

[0060] PWM modulation strategy: Optimize the PWM modulation strategy, adjust the pulse width during switching, and reduce output fluctuations.

[0061] 5) Switching performance evaluation: Evaluation indicators: Define performance evaluation indicators such as switching time and energy loss.

[0062] Feedback adjustment: Based on the performance evaluation results, feedback is used to adjust the switching logic and circuit parameters.

[0063] By implementing the steps in the above-mentioned fast switching mechanism, it is possible to minimize energy loss while ensuring the switching speed, thereby improving the overall performance of the three-phase inverter in an off-grid state.

[0064] In order 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 the changing load conditions and environmental factors, thereby improving the overall performance and energy efficiency of the inverter in the off-grid state: 1) Real-time data analysis: Data collection: High-precision collection of key parameters such as the inverter's output voltage, current, power factor, etc.

[0065] Data processing: Use digital signal processing technology to filter, analyze and extract features from the collected data.

[0066] 2) Control strategy optimization: Model building: A mathematical model of the inverter output performance is established based on the collected data.

[0067] Parameter optimization: The above optimization model (such as particle swarm optimization or genetic algorithm) is used to iteratively optimize the parameters of the above adaptive control model.

[0068] 3) Dynamic parameter adjustment: Adaptive control: Adaptively adjust the inverter operating point based on real-time data analysis results to achieve optimal performance.

[0069] Feedback mechanism: Establish a feedback mechanism to monitor output performance in real time and adjust control parameters in a timely manner.

[0070] 4) Performance evaluation: Evaluation indicators: Define performance evaluation indicators including efficiency, stability, response time, etc.

[0071] Continuous improvement: Based on the performance evaluation results, the optimization algorithm is continuously adjusted, and the performance of the inverter in the off-grid state is optimized through continuous data analysis and parameter adjustment.

[0072] By implementing the steps in the above performance optimization strategy, it can be ensured that the inverter can not only respond quickly to load changes when off-grid, but also improve energy conversion efficiency while ensuring stable output, thereby achieving a dual improvement in performance and energy efficiency.

[0073] The embodiments of the present application can significantly optimize the performance of the three-phase inverter in the absence of grid support, so that it can maintain stable output even when the load changes rapidly, thereby improving its power supply quality and system reliability.

[0074] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented with 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. Computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0075] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, 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; Based on the current and historical change data of the output control parameter, it is predicted whether the output control parameter will oscillate within the next preset time period. If so, a control increment is generated to suppress the oscillation and adjust the output control parameter to a preset stable range.

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 is increased to a range matching the load change; If the load change type is a sudden decrease, then reducing 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 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. The method according to any one of claims 1 to 4, characterized in that The following prediction model is used 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. 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; The oscillation prediction and suppression unit is used to predict whether the output control parameter is likely to oscillate within the next preset time period based on the current and historical change data of the output control parameter. If so, a control increment for suppressing the oscillation is generated through an incremental control model to adjust the output control parameter to a preset stable range.

7. The system according to claim 6, 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.

8. The system according to claim 7, characterized in that The load change response unit specifically includes: a change type identification unit, configured to detect that a change value of the output control parameter exceeds a preset threshold, determine that a sudden change has occurred in the load, 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, fine-tuning 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 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.

9. The system according to claim 8, 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.

10. The system according to any one of claims 6 to 9, characterized in that: 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.

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