An intelligent control system and method for off-grid inverter

Abstract

The present invention relates to the technical field of inverter control systems and provides an intelligent control system and method for an off-grid inverter. The system includes a sensor data monitoring terminal, an intelligent analysis terminal, a control signal generation terminal, an output regulation terminal, and a fault prevention terminal. The sensor data monitoring terminal is used to collect voltage, current, and temperature data of the off-grid inverter. The intelligent analysis terminal is used to analyze the collected data, determine the current operating status of the off-grid inverter, predict load change trends, and generate intelligent analysis information. The control signal generation terminal is used to generate a control signal based on the intelligent analysis information, which is used to adjust the output parameters of the off-grid inverter. The output regulation terminal is used to adjust the output of the off-grid inverter based on the control signal. The fault prevention terminal is used to sense faults during the operation of the off-grid inverter and generate and execute safety measures. The present invention has the effect of improving the operating stability of the inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter control systems, and in particular to an intelligent control system and method for an off-grid inverter. Background Art

[0002] An off-grid inverter is a device specifically designed for use in standalone power supply systems. It is typically used in locations disconnected from the grid or in situations where grid access is unavailable, providing stable AC power to the system. Unlike grid-connected inverters, off-grid inverters do not rely on grid power. They are often combined with battery energy storage systems to ensure continuous power supply in the absence of a grid. The intelligent control system for off-grid inverters is a comprehensive system that combines modern control, sensor, and information technologies to improve the performance, efficiency, and reliability of off-grid inverters. Through intelligent algorithms and real-time monitoring, this system dynamically adjusts the inverter's operating parameters to adapt to changing load conditions and battery status, ensuring a stable and efficient power supply.

[0003] Many inverter control systems have been developed. After extensive research and reference, we discovered that existing inverter control systems include those disclosed in publications CN105915093A, CN116260354A, CN103299536A, EP3805038A1, US20160248317A1, and JP2017189086A. These inverter control systems generally include: a data acquisition terminal, a data analysis terminal, and a control terminal; the data acquisition terminal is used to collect inverter operating data and load operating data; the data analysis terminal is used to perform data analysis based on the operating and operating data; and the control terminal is used to output inverter control instructions based on the data analysis results. Because the inverter control process of these systems is relatively simple, it is not conducive to providing stable power supply to different loads, resulting in a defect of reduced inverter operating stability. Summary of the Invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned inverter control system and to provide an intelligent control system and method for an off-grid inverter.

[0005] The present invention adopts the following technical solutions:

[0006] An intelligent control system for an off-grid inverter, comprising a sensor data monitoring terminal, an intelligent analysis terminal, a control signal generation terminal, an output regulation terminal, and a fault prevention terminal; the sensor data monitoring terminal is used to collect voltage, current, and temperature data of the off-grid inverter; the intelligent analysis terminal is used to analyze the collected data, determine the current operating status of the off-grid inverter, predict load change trends, and generate intelligent analysis information; the control signal generation terminal is used to generate a control signal based on the intelligent analysis information, for adjusting the output parameters of the off-grid inverter; the output regulation terminal is used to regulate the output of the off-grid inverter based on the control signal; and the fault prevention terminal is used to sense faults during the operation of the off-grid inverter and generate and execute safety measures.

[0007] The sensor data monitoring terminal includes a voltage data monitoring module, a current data monitoring module and a temperature data monitoring module; the voltage data monitoring module is used to collect voltage data during the operation of the off-grid inverter; the current data monitoring module is used to collect current data during the operation of the off-grid inverter; the temperature data monitoring module is used to collect temperature data during the operation of the off-grid inverter.

[0008] Optionally, the control signal generating terminal includes an output voltage compensation value calculation module and a control signal generating module; the output voltage compensation value calculation module is used to calculate the output voltage compensation value based on the operating data and load conditions of the off-grid inverter; the control signal generating module is used to generate a corresponding control signal based on the output voltage compensation value, so that the system can output an adaptive voltage signal under different load conditions.

[0009] Optionally, the output regulation terminal includes a normal regulation module and a temperature abnormality regulation module; the normal regulation module is used to regulate the output of the off-grid inverter according to the control signal; the temperature abnormality regulation module is used to regulate the voltage output of the off-grid inverter when the temperature of the off-grid inverter is abnormal.

[0010] Optionally, the fault prevention terminal includes a fault risk assessment module and a safety measures execution module; the fault risk assessment module is used to calculate the fault risk assessment score based on the data during the operation of the off-grid inverter; the safety measures execution module is used to select and execute corresponding safety measures based on the fault risk assessment score.

[0011] Optionally, the output voltage compensation value calculation module includes a reference voltage reading submodule, a harmonic component superposition submodule, a dynamic compensation submodule, a real-time adaptive submodule and an output voltage compensation value output submodule; the reference voltage reading submodule is used to read the reference output voltage value input by the operation and maintenance personnel; the harmonic component superposition submodule is used to control the amplitude and phase of the harmonics, suppress the harmonic components in the output in real time, and calculate the harmonic component superposition term; the dynamic compensation submodule is used to compensate for the voltage fluctuation caused by the load change according to the dynamic change characteristics of the load, and calculate the dynamic compensation term; the real-time adaptive submodule is used to automatically adjust the stability of the output voltage and the harmonic suppression effect according to the load change, and adjust the dynamic parameters in the dynamic compensation term; the output voltage compensation value output submodule is used to calculate the output voltage compensation value based on the reference output voltage value, the harmonic component superposition term, the dynamic compensation term and the dynamic parameters.

[0012] An intelligent control method for an off-grid inverter is applied to the intelligent control system of the off-grid inverter as described above. The intelligent control method for the off-grid inverter includes:

[0013] S1, collects voltage, current and temperature data of the off-grid inverter;

[0014] S2, analyzes the collected data, determines the current operating status of the off-grid inverter, predicts the load change trend, and generates intelligent analysis information;

[0015] S3, generating a control signal based on the intelligent analysis information to adjust the output parameters of the off-grid inverter;

[0016] S4, adjusting the output of the off-grid inverter according to the control signal;

[0017] S5, performing fault sensing during the operation of the off-grid inverter, and generating and executing safety measures.

[0018] The beneficial effects achieved by the present invention are:

[0019] 1. The sensor data monitoring terminal, intelligent analysis terminal, control signal generation terminal, output regulation terminal, and fault prevention terminal are configured. The sensor data monitoring terminal includes the voltage data monitoring module, current data monitoring module, and temperature data monitoring module. This improves data monitoring quality and stability by independently monitoring key data. Furthermore, the intelligent analysis, output regulation, and fault prevention functions enrich the control process, thereby improving the accuracy and stability of the control process. This allows the system to operate stably under different inverters and loads, thereby improving the working stability of the inverter.

[0020] 2. Output regulation and temperature anomaly regulation are performed through the settings of the output voltage compensation value calculation module and the control signal generation module, which is conducive to further enriching the control process and control mode, thereby further improving the working stability of the inverter;

[0021] 3. The setting of the normal regulation module and the temperature abnormality regulation module is conducive to achieving independent control of normal regulation and temperature abnormality regulation, improving the stability of the control process, and thus facilitating more accurate and stable regulation of the inverter;

[0022] 4. By setting up the fault risk assessment module and the safety measure execution module, the fault risk assessment score can be quickly and accurately calculated based on the data during the off-grid inverter's operation. Then, the corresponding safety measures can be selected and executed based on the fault risk assessment score. This helps to improve the accuracy of safety measure selection and the stability of execution, reduces the risk of off-grid inverter failure, and thus helps to improve the working stability of the inverter.

[0023] 5. By setting the reference voltage reading submodule, harmonic component superposition submodule, dynamic compensation submodule, real-time adaptive submodule and output voltage compensation value output submodule in conjunction with the output voltage compensation value output algorithm, the reference output voltage value, harmonic component superposition item, dynamic compensation item and dynamic parameter are calculated respectively, and then the output voltage compensation value is calculated. This is conducive to improving the calculation accuracy of the output voltage compensation value, and further conducive to improving the adaptability of the output voltage compensation process to different loads, thereby helping to improve the working stability of the inverter;

[0024] 6. By configuring the temperature anomaly determination submodule, the temperature anomaly voltage compensation value calculation submodule, and the temperature anomaly voltage output regulation submodule in conjunction with the temperature anomaly voltage compensation value algorithm, the temperature anomaly voltage compensation value is calculated based on the temperature change of the off-grid inverter and the reference output voltage. This is beneficial to improving the accuracy of the temperature anomaly voltage compensation value, thereby improving the working quality of the off-grid inverter under temperature anomalies, thereby further improving the working stability of the inverter;

[0025] 7. By setting up the monitoring data acquisition submodule and the fault risk assessment score calculation submodule in conjunction with the fault risk assessment score algorithm, calculating the fault risk assessment score based on real-time monitoring data is conducive to improving the accuracy and timeliness of the fault risk assessment score, thereby improving the accuracy and timeliness of the implementation of safety measures, thereby greatly improving the working stability of the inverter.

[0026] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and illustration and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 Schematic diagram of the structure of the output voltage compensation value calculation module in the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the temperature anomaly adjustment module in the present invention;

[0030] Figure 4 A schematic diagram of a method flow of an intelligent control method for an off-grid inverter in the present invention;

[0031] Figure 5 FIG. 4 is a structural diagram of a fault risk assessment module in another embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only for simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0033] Example 1: This example provides an intelligent control system for an off-grid inverter. Figure 1 As shown, an intelligent control system for an off-grid inverter includes a sensor data monitoring terminal, an intelligent analysis terminal, a control signal generation terminal, an output regulation terminal, and a fault prevention terminal; the sensor data monitoring terminal is used to collect voltage, current, and temperature data of the off-grid inverter; the intelligent analysis terminal is used to analyze the collected data, determine the current operating status of the off-grid inverter, and predict load change trends to generate intelligent analysis information; the control signal generation terminal is used to generate a control signal based on the intelligent analysis information, which is used to adjust the output parameters of the off-grid inverter; the output regulation terminal is used to regulate the output of the off-grid inverter based on the control signal; and the fault prevention terminal is used to sense faults during the operation of the off-grid inverter and generate and execute safety measures;

[0034] The sensor data monitoring terminal includes a voltage data monitoring module, a current data monitoring module and a temperature data monitoring module; the voltage data monitoring module is used to collect voltage data during the operation of the off-grid inverter; the current data monitoring module is used to collect current data during the operation of the off-grid inverter; the temperature data monitoring module is used to collect temperature data during the operation of the off-grid inverter.

[0035] Optionally, the control signal generating terminal includes an output voltage compensation value calculation module and a control signal generating module; the output voltage compensation value calculation module is used to calculate the output voltage compensation value based on the operating data and load conditions of the off-grid inverter; the control signal generating module is used to generate a corresponding control signal based on the output voltage compensation value, so that the system can output an adaptive voltage signal under different load conditions.

[0036] Optionally, the output regulation terminal includes a normal regulation module and a temperature abnormality regulation module; the normal regulation module is used to regulate the output of the off-grid inverter according to the control signal; the temperature abnormality regulation module is used to regulate the voltage output of the off-grid inverter when the temperature of the off-grid inverter is abnormal.

[0037] Optionally, the fault prevention terminal includes a fault risk assessment module and a safety measures execution module; the fault risk assessment module is used to calculate the fault risk assessment score based on the data during the operation of the off-grid inverter; the safety measures execution module is used to select and execute corresponding safety measures based on the fault risk assessment score.

[0038] Optional, combined Figure 2 As shown, the output voltage compensation value calculation module includes a reference voltage reading submodule, a harmonic component superposition submodule, a dynamic compensation submodule, a real-time adaptive submodule and an output voltage compensation value output submodule; the reference voltage reading submodule is used to read the reference output voltage value input by the operation and maintenance personnel; the harmonic component superposition submodule is used to control the amplitude and phase of the harmonics, suppress the harmonic components in the output in real time, and calculate the harmonic component superposition term; the dynamic compensation submodule is used to compensate for the voltage fluctuation caused by the load change according to the dynamic change characteristics of the load, and calculate the dynamic compensation term; the real-time adaptive submodule is used to automatically adjust the stability of the output voltage and the harmonic suppression effect according to the load change, and adjust the dynamic parameters in the dynamic compensation term; the output voltage compensation value output submodule is used to calculate the output voltage compensation value according to the reference output voltage value, the harmonic component superposition term, the dynamic compensation term and the dynamic parameters.

[0039] Specifically, when the output voltage compensation value output submodule is working, the following formula is satisfied:

[0040] ;

[0041] ;

[0042] Among them, V comp (t) represents the output voltage compensation value at time t; V ref Indicates the reference output voltage value; a k and b k They represent the amplitude coefficients of different harmonic components, which are known values ​​in the formula. The specific values ​​are extracted by the system from the voltage signal collected in real time. The system can be directly measured by equipment or modules such as harmonic analyzers; k represents the kth harmonic generated by the load; n represents the number of harmonic types; w k represents the angular frequency of the kth harmonic, which is directly measured by the system; ϕ k and φ k They represent different phase angles, which are used to determine the starting position of the kth harmonic signal on the time axis. They are known values ​​in the formula. The specific values ​​are extracted by the system from the real-time collected voltage signal. The system can be directly measured by devices or modules such as phase analyzers; k and φ k They are the phase angle of the sine signal and the phase angle of the cosine signal respectively; the phase angle of the sine signal adjusts the initial phase of the sine wave, that is, the position of the initial time point of the waveform; the phase angle of the cosine signal adjusts the initial phase of the cosine wave, that is, the offset relative to the time zero point; λ k It represents the attenuation coefficient of the harmonic component. The higher the frequency of the harmonic, the greater the attenuation coefficient. The specific value is set by the operation and maintenance personnel based on experience or historical data. η(t) represents the adaptive adjustment value. The larger the reference output voltage value, the greater the adaptive adjustment value. The specific value is set by the operation and maintenance personnel based on experience or historical data. D(t) represents the integral compensation. and They represent different dynamic compensation coefficients, with specific values ​​set by operations and maintenance personnel based on experience. The goal is to compensate for voltage fluctuations caused by load changes through a combination of sine and cosine functions. w' represents the compensation angular frequency, which is set based on the current system operating frequency and the expected compensation target, and can also be pre-set according to the system design specifications. t' is the integral variable, representing the system's changes at any point in time. t' is the upper limit of the integral, representing the current time point and determining the range of the integral, i.e., the time window of the accumulated signal from t' = 0 to t'.

[0043] For example, at an industrial site, an off-grid inverter supplies power to a motor drive system. This load generates three types of harmonics: the third harmonic (150 Hz), the fifth harmonic (250 Hz), and the seventh harmonic (350 Hz). The following parameters are known: Reference output voltage V ref=230V; harmonic frequencies w3=2π*150rad / s, w5=2π*250rad / s, w7=2π*350rad / s; amplitude coefficients a3=10, b3=5, a5=7, b5=3, a7=5, b7=2; phase angle 、 、 、 、 、 Attenuation coefficients λ3=0.1, λ5=0.15, λ7=0.2; η(t)=0.05*t, time t is 0.02s; 、 、 The calculation process is as follows:

[0044] Step 1: Calculate the harmonic suppression part:

[0045] ;

[0046] ;

[0047] ;

[0048] So the formula The terms in this example are:

[0049] ;

[0050] Step 2: Calculate the dynamic compensation part:

[0051] ;

[0052] ;

[0053] Therefore, the dynamic compensation part is 0.0002V;

[0054] Step 3: Calculate the output voltage compensation value:

[0055] ;

[0056] In this specific example, the system's dual adaptive control mechanism achieved harmonic suppression and dynamic compensation for the off-grid inverter's output voltage at time t = 0.02 seconds. Because the system detected harmonics and load fluctuations, it compensated for the output voltage, ultimately achieving a compensated output voltage of 227.6296V, a decrease from the reference output voltage of 230V. This ensures the system maintains a stable power supply even with complex nonlinear loads, thereby protecting the normal operation of on-site equipment.

[0057] Optional, combined Figure 3 As shown, the temperature abnormality adjustment module includes a temperature abnormality determination submodule, a temperature abnormality voltage compensation value calculation submodule and a temperature abnormality voltage output adjustment submodule; the temperature abnormality determination submodule is used to determine the temperature state of the operating temperature of the off-grid inverter; when the temperature abnormality determination submodule determines that the temperature state of the operating temperature of the off-grid inverter is abnormal, the temperature abnormality voltage compensation value calculation submodule is used to calculate the temperature abnormality voltage compensation value according to the temperature change of the off-grid inverter and the reference output voltage; the temperature abnormality voltage output adjustment submodule is used to adjust the voltage output of the off-grid inverter when the temperature is abnormal according to the temperature abnormality voltage compensation value.

[0058] Specifically, when the temperature anomaly voltage compensation value calculation submodule is working, the following formula is satisfied:

[0059] V T= ;

[0060] Among them, V T Indicates the temperature abnormality voltage compensation value; V out Indicates the output voltage value of the off-grid inverter when calculating the temperature abnormality voltage compensation value; δ1 represents the linear temperature compensation coefficient, which is set by the operation and maintenance personnel based on experience or historical data to achieve basic compensation for temperature changes. This part is the most basic compensation mechanism, which assumes that the temperature and output voltage are linearly related. inverter Indicates the current temperature of the off-grid inverter when the temperature is abnormal; T ref represents the reference temperature, which is set by the operation and maintenance personnel based on experience or historical data; ε represents the nonlinear temperature compensation parameter, which is set by the operation and maintenance personnel based on experience or historical data; μ represents the exponential attenuation coefficient, which is generally 0.1 and is set by the operation and maintenance personnel based on experience; Represents the nonlinear compensation term, ensuring that the compensation strength is significantly enhanced when the temperature difference is large, and the voltage offset is quickly suppressed. Specifically, when the temperature is significantly higher or lower than the reference temperature, the exponential decay term The smaller the value of , the smaller the denominator, which in turn increases the entire compensation coefficient, thus more effectively compensating the voltage. δ2 represents the sinusoidal modulation coefficient, which is set by the operation and maintenance personnel based on experience or historical data. T Indicates the sinusoidal modulation frequency, generally 2π×1 rad / s. The setting is designed to fine-tune small temperature fluctuations to prevent small fluctuations in output voltage caused by slight temperature changes. This sinusoidal modulation method can be regarded as a fine adjustment for temperature fluctuations, ensuring that the system can maintain a stable voltage output when the temperature changes.

[0061] Example: Assume that in a solar power station, the off-grid inverter works in a high temperature environment. The reference temperature T ref is 25 degrees Celsius, while the actual operating temperature T inverter Reached 45 degrees Celsius. The output voltage of the off-grid inverter is V out The known parameters are as follows: δ1=0.01, ε=0.5, μ=0.1, δ2=0.005, w T =2π×1 rad / s. The calculation process of temperature abnormality voltage compensation value is as follows:

[0062] Step 1: Calculate the linear temperature compensation part.

[0063] = =

[0064] Step 2: Calculate the sinusoidal modulation term.

[0065] .

[0066] Step 3: Calculate the temperature abnormality voltage compensation value.

[0067] .

[0068] In this example, because the off-grid inverter's temperature was 20°C higher than the reference temperature, the system employed linear and nonlinear temperature compensation mechanisms to increase the output voltage from 230V to 273.08V. Even in high-temperature environments, the off-grid inverter maintains a stable voltage output, preventing performance degradation or damage caused by high temperatures. This compensation mechanism is particularly useful in scenarios where the off-grid inverter operates in high or low temperatures for extended periods, or in environments with abnormal temperatures, ensuring device safety and power supply stability.

[0069] In summary, through the setting of sensor data monitoring terminal, intelligent analysis terminal, control signal generation terminal, output regulation terminal and fault prevention terminal, combined with the setting of sensor data monitoring terminal including voltage data monitoring module, current data monitoring module and temperature data monitoring module, the data monitoring quality and stability are first improved by independently monitoring the main data respectively, and then the control process is enriched by the functions of intelligent analysis, output regulation and fault prevention, which is conducive to improving the accuracy and stability of the control process, so that the system can work stably when facing different inverters and different loads; output regulation and temperature anomaly regulation are carried out through the setting of output voltage compensation value calculation module and control signal generation module, which is conducive to further enriching the control process and control mode; through the setting of normal regulation module and temperature anomaly regulation module, it is conducive to realizing independent control of normal regulation and temperature anomaly regulation, and improving the stability of the control process; through the setting of fault risk assessment module and safety measure execution module, the fault risk assessment score is quickly and accurately calculated according to the data during the working process of the off-grid inverter, and then according to Selecting and executing corresponding safety measures based on the fault risk assessment score is conducive to improving the accuracy of safety measure selection and the stability of execution, and reducing the risk of off-grid inverter failure; through the setting of the reference voltage reading submodule, the harmonic component superposition submodule, the dynamic compensation submodule, the real-time adaptive submodule and the output voltage compensation value output submodule, in conjunction with the output voltage compensation value output algorithm, the reference output voltage value, the harmonic component superposition item, the dynamic compensation item and the dynamic parameter are calculated respectively, and then the output voltage compensation value is calculated, which is conducive to improving the calculation accuracy of the output voltage compensation value, and thus is conducive to improving the adaptability of the output voltage compensation process to different responsibilities; through the setting of the temperature anomaly judgment submodule, the temperature anomaly voltage compensation value calculation submodule and the temperature anomaly voltage output adjustment submodule, in conjunction with the temperature anomaly voltage compensation value algorithm, the temperature anomaly voltage compensation value is calculated according to the temperature change of the off-grid inverter and the reference output voltage, which is conducive to improving the accuracy of the temperature anomaly voltage compensation value, and thus improves the working quality of the off-grid inverter under temperature anomaly, thereby helping to improve the working stability of the inverter.

[0070] An intelligent control method for an off-grid inverter is applied to an intelligent control system of an off-grid inverter as described above, combined with Figure 4 As shown, the intelligent control method of the off-grid inverter includes:

[0071] S1, collects voltage, current and temperature data of the off-grid inverter;

[0072] S2, analyzes the collected data, determines the current operating status of the off-grid inverter, predicts the load change trend, and generates intelligent analysis information;

[0073] S3, generating a control signal based on the intelligent analysis information to adjust the output parameters of the off-grid inverter;

[0074] S4, adjusting the output of the off-grid inverter according to the control signal;

[0075] S5, performing fault sensing during the operation of the off-grid inverter, and generating and executing safety measures.

[0076] Example 2: This example includes all the contents of Example 1, and provides an intelligent control system for an off-grid inverter. Figure 5 As shown, the fault risk assessment module includes a monitoring data acquisition submodule and a fault risk assessment score calculation submodule; the monitoring data acquisition submodule is used to obtain real-time monitoring data of the off-grid inverter; the real-time monitoring data includes voltage monitoring data, current monitoring data, temperature monitoring data and vibration monitoring data; the fault risk assessment score calculation submodule is used to calculate the fault risk assessment score based on the real-time monitoring data;

[0077] Specifically, when the fault risk assessment score is working, the following formula is satisfied:

[0078] ;

[0079] Among them, F risk (t) represents the fault risk assessment score of the off-grid inverter at time t; f i (D monitor (t)) represents the basic risk value of the i-th real-time monitoring data, and its specific value is the difference between the real-time monitoring data and the safety reference value; n represents the total number of real-time monitoring data; in this embodiment, n=4; w i represents the risk assessment weight of the i-th type of real-time monitoring data, which is set by the operation and maintenance personnel based on experience. Generally, w1 is the risk assessment weight of voltage monitoring data, with a value of 0.4; w2 is the risk assessment weight of current monitoring data, with a value of 0.3; w3 is the risk assessment weight of temperature monitoring data, with a value of 0.2; and w4 is the risk assessment weight of vibration monitoring data, with a value of 0.1; σ i The adjustment coefficient for the i-th type of real-time monitoring data is set by the operation and maintenance personnel based on experience. If the current monitoring data type is risky, the adjustment coefficient can be set large, otherwise it can be set small. The risk increment of the monitoring data change rate is used to reflect the additional risk brought by the dynamic change of monitoring data; D monitor (t) represents the real-time monitoring data of item i; The monitoring data change rate of the i-th real-time monitoring data indicates the speed of change of the real-time monitoring data. The faster the change, the potential abnormality or failure. represents the time decay factor of the i-th real-time monitoring data, which is used to limit the long-term impact of drastic changes in a short period of time on the overall risk assessment; ρ i represents the time decay coefficient of the i-th real-time monitoring data. The higher the update frequency of the real-time monitoring data, the larger the time decay coefficient. The specific value is set by the operation and maintenance personnel based on experience; time (t) represents the long-term trend cumulative risk benchmark value. Generally, γ time (t)=0.001t; t represents time t, that is, the tth second after the off-grid inverter starts working.

[0080] Let's take an example: In a power system, voltage, current, temperature, and vibration sensors are included. These sensors monitor the system's operating status in real time. The above formula is used to assess the system's failure risk at a given moment, and preventive measures are taken based on the risk value. The known parameter settings are as follows:

[0081] The voltage monitoring data at time t is 230V, with a change rate of -0.5V / s; the current monitoring data at time t is 10A, with a change rate of 0.1A / s; the temperature monitoring data at time t is 60°C, with a change rate of 2°C; the vibration monitoring data at time t is 0.02g, with a change rate of 0.005g / s; w1 is the risk assessment weight for voltage monitoring data, with a value of 0.4; w2 is the risk assessment weight for current monitoring data, with a value of 0.3; w3 is the risk assessment weight for temperature monitoring data, with a value of 0.2; and w4 is the risk assessment weight for vibration monitoring data, with a value of 0.1; the voltage adjustment coefficient is 0.2, the current adjustment coefficient is 0.3, the temperature adjustment coefficient is 0.5, and the vibration adjustment coefficient is 0.4; the voltage time decay coefficient is 0.05, the current time decay coefficient is 0.02, the temperature time decay coefficient is 0.1, and the vibration time decay coefficient is 0.15; and t is 5s. The fault risk assessment score is calculated using the following steps:

[0082] Step 1: Calculate the failure risk contribution of each real-time monitoring data.

[0083] For voltage, 240V is used as a safe reference value:

[0084] ;

[0085] Voltage change rate risk increment for ;

[0086] Voltage risk contribution is ;

[0087] For the current part, 10A is used as a safe reference value for current:

[0088] ;

[0089] Current rate of change risk increment for ;

[0090] The current risk contribution is ;

[0091] For temperature, 40℃ is used as a safe reference value:

[0092] ;

[0093] Temperature change rate risk increment for ;

[0094] Temperature risk contribution is ;

[0095] For vibration, 0.01g is used as a reference value for vibration safety:

[0096] ;

[0097] Vibration rate of change risk increment for ;

[0098] The vibration risk contribution is ;

[0099] Step 2: Calculate the total risk value, that is, the fault risk assessment score at time t=5.

[0100] .

[0101] In this specific example, through real-time monitoring and analysis of voltage, current, temperature and vibration data, the fault risk assessment score at the current moment is calculated to be 8.1594. Based on this risk value, the safety measure execution module can take corresponding preventive measures, such as increasing cooling, reducing load or starting the backup system, to prevent potential faults from causing more serious problems. The fault risk assessment scores in different intervals are preset with corresponding safety measures, so that safety measures can be quickly implemented according to the fault risk assessment scores. Since the contributions of temperature and voltage are generally the largest, it shows that these two parameters have an important impact on the safety of the system. Therefore, the system can, but is not limited to, give priority to temperature and voltage control, such as reducing the temperature by increasing cooling or reducing the load, or reducing the risk of voltage fluctuations by adjusting the voltage stabilizer.

[0102] In summary, by setting up the monitoring data acquisition submodule and the fault risk assessment score calculation submodule in conjunction with the fault risk assessment score algorithm, calculating the fault risk assessment score based on real-time monitoring data is conducive to improving the accuracy and timeliness of the fault risk assessment score, thereby improving the accuracy and timeliness of the execution of safety measures, thereby greatly improving the working stability of the inverter.

[0103] The contents disclosed above are only preferred feasible embodiments of the present invention and do not limit the scope of protection of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the scope of protection of the present invention. In addition, the elements therein can be updated as technology develops.

Claims

1. An intelligent control system for an off-grid inverter, characterized in that: It includes a sensor data monitoring terminal, an intelligent analysis terminal, a control signal generation terminal, an output regulation terminal, and a fault prevention terminal; the sensor data monitoring terminal is used to collect voltage, current, and temperature data of the off-grid inverter; the intelligent analysis terminal is used to analyze the collected data, determine the current operating status of the off-grid inverter, and predict the load change trend to generate intelligent analysis information; the control signal generation terminal is used to generate a control signal based on the intelligent analysis information to adjust the output parameters of the off-grid inverter; the output regulation terminal is used to adjust the output of the off-grid inverter based on the control signal; the fault prevention terminal is used to sense faults during the operation of the off-grid inverter and generate and execute safety measures; When the control signal generating terminal is working, the following formula is satisfied: ； ； Among them, V comp (t) represents the output voltage compensation value at time t; V ref Indicates the reference output voltage value; a k and b k They represent the amplitude coefficients of different harmonic components respectively; k represents the kth harmonic generated by the load; n represents the number of harmonic types; w k represents the angular frequency of the kth harmonic; and are the phase angles of the sine signal and the cosine signal respectively; λ k represents the attenuation coefficient of the harmonic component; η(t) represents the adaptive adjustment value; D(t) represents the integral compensation; and Represent different dynamic compensation coefficients respectively; w' represents the compensation angular frequency; t' is the integral variable; t is the upper limit of the integral, indicating the current time point; The sensor data monitoring terminal includes a voltage data monitoring module, a current data monitoring module and a temperature data monitoring module; the voltage data monitoring module is used to collect voltage data during the operation of the off-grid inverter; the current data monitoring module is used to collect current data during the operation of the off-grid inverter; the temperature data monitoring module is used to collect temperature data during the operation of the off-grid inverter.

2. The intelligent control system for an off-grid inverter according to claim 1, characterized in that: The control signal generating terminal includes an output voltage compensation value calculation module and a control signal generating module; the output voltage compensation value calculation module is used to calculate the output voltage compensation value according to the operating data and load conditions of the off-grid inverter; the control signal generating module is used to generate a corresponding control signal according to the output voltage compensation value, so that the system can output an adaptive voltage signal under different load conditions.

3. The intelligent control system for an off-grid inverter according to claim 2, characterized in that: The output regulation terminal includes a normal regulation module and a temperature abnormality regulation module; the normal regulation module is used to regulate the output of the off-grid inverter according to the control signal; the temperature abnormality regulation module is used to regulate the voltage output of the off-grid inverter when the temperature of the off-grid inverter is abnormal.

4. The intelligent control system for an off-grid inverter according to claim 3, characterized in that: The fault prevention terminal includes a fault risk assessment module and a safety measure execution module; The fault risk assessment module is used to calculate the fault risk assessment score based on the data during the working process of the off-grid inverter; The safety measure execution module is used to select and execute corresponding safety measures according to the fault risk assessment score.

5. The intelligent control system for an off-grid inverter according to claim 4, characterized in that: The output voltage compensation value calculation module includes a reference voltage reading submodule, a harmonic component superposition submodule, a dynamic compensation submodule, a real-time adaptive submodule and an output voltage compensation value output submodule; The reference voltage reading submodule is used to read the reference output voltage value input by the operation and maintenance personnel; The harmonic component superposition submodule is used to control the amplitude and phase of the harmonics, suppress the harmonic components in the output in real time, and calculate the harmonic component superposition term; The dynamic compensation submodule is used to compensate for voltage fluctuations caused by load changes according to the dynamic change characteristics of the load, and calculate the dynamic compensation term; the real-time adaptive submodule is used to automatically adjust the stability of the output voltage and the harmonic suppression effect according to the load change, and adjust the dynamic parameters in the dynamic compensation term; the output voltage compensation value output submodule is used to calculate the output voltage compensation value according to the reference output voltage value, the harmonic component superposition term, the dynamic compensation term and the dynamic parameters.

6. An intelligent control method for an off-grid inverter, applied to the intelligent control system for an off-grid inverter according to claim 5, characterized in that: The intelligent control method of the off-grid inverter includes: S1, collects voltage, current and temperature data of the off-grid inverter; S2, analyzes the collected data, determines the current operating status of the off-grid inverter, predicts the load change trend, and generates intelligent analysis information; S3, generating a control signal based on the intelligent analysis information to adjust the output parameters of the off-grid inverter; S4, adjusting the output of the off-grid inverter according to the control signal; S5, performing fault sensing during the operation of the off-grid inverter, and generating and executing safety measures.

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