Grid-connected and off-grid control system and method for wind turbine generator

Abstract

The invention provides a grid-connected and off-grid control system and method for a wind turbine generator. A control module judges a system operation mode by monitoring a real-time state of a power grid side of a boosting transformer. When the power grid is normal, the wind turbine generator generates power through the boosting transformer in a grid-connected mode and supplies power to the power grid preferentially. And when the power grid has a fault or the voltage fluctuation exceeds a threshold value, switching to an off-grid mode, and supplying power to a local load by the wind turbine generator, the energy storage module and the diesel generator set. The power utilization requirements in the grid-connected mode and the off-grid mode are determined through the simulation load, whether power distribution is reasonable or not is verified according to the power utilization requirements, and stable power supply of the power utilization load is ensured. In the grid-connected mode, the control module adjusts the output power of the wind turbine generator and controls the charging and discharging of the energy storage module according to the demand of a power grid and the power generation capacity of the wind turbine generator, so as to stabilize the power fluctuation; in the off-grid mode, the control module coordinates the output of the wind turbine generator set, the diesel generator set and the energy storage module according to the change of the electrical load.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a wind turbine grid-connected and off-grid control system and method. Background Technology

[0002] In grid-connected mode, wind turbines need to maintain synchronization with the power grid and possess fault ride-through capability to ensure stable operation when grid anomalies occur. In off-grid mode, wind turbines need to autonomously support the load to maintain voltage and frequency stability. However, the output power of wind turbines is significantly affected by wind speed, exhibiting strong intermittency and volatility, which poses a significant challenge to grid-connected and off-grid control.

[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0004] The purpose of this application is to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the first objective of this application is to propose an off-grid control system for wind turbine generators.

[0006] The second objective of this application is to propose a method for controlling wind turbine generators both on and off the grid.

[0007] The third objective of this application is to propose an electronic device.

[0008] The fourth objective of this application is to provide a computer-readable storage medium.

[0009] The fifth objective of this application is to provide a computer program product.

[0010] To achieve the above objectives, the first aspect of this application proposes a wind turbine grid-connected and off-grid control system, including a wind turbine, a converter, a step-up transformer, a distribution transformer, an energy storage module, a diesel generator set, an electrical load, a simulated load, and a control module, wherein: The converter includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the wind turbine generator set, the first output terminal is connected to the power grid via the step-up transformer, and the second output terminal is connected to the input terminal of the distribution transformer. The energy storage module, the diesel generator set, the electrical load, and the simulated load are all connected to the output terminal of the distribution transformer. The diesel generator set is used to provide supplementary power, the simulated load is used to test the power demand in grid-connected and off-grid modes, and the distribution transformer is used for power distribution. The control module is connected to the wind turbine, the step-up transformer, the distribution transformer, the energy storage module, the diesel generator set, the electrical load, and the simulated load. It determines whether the wind turbine is in grid-connected or off-grid mode by monitoring the real-time status of the grid side of the step-up transformer, and controls the output power of the wind turbine and the diesel generator set, the charging and discharging status of the energy storage module, the power distribution status of the distribution transformer, and the operating status of the electrical load and the simulated load based on the determination result.

[0011] To achieve the above objectives, a second aspect of this application provides a wind turbine grid-connected / off-grid control method, applicable to the wind turbine grid-connected / off-grid control system proposed in the first aspect of this application, comprising: Obtain real-time operating data of the step-up transformer on the grid side; The wind turbine is determined to be either in grid-connected or off-grid mode based on the real-time operating data. Based on the judgment results, the output power of wind turbines and diesel generators, the charging and discharging status of energy storage modules, the power distribution status of distribution transformers, and the operating status of electrical loads and simulated loads are controlled.

[0012] To achieve the above objectives, a third aspect of this application provides an electronic device, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the wind turbine grid connection / off-grid control method proposed in the second aspect of this application.

[0013] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium that, when the instructions in the storage medium are executed by a processor of an electronic device, enables the electronic device to execute the wind turbine off-grid control method proposed in the second aspect of this application.

[0014] To achieve the above objectives, a fifth aspect of this application provides a computer program product, including a computer program that, when executed by a processor in a communication device, implements the wind turbine off-grid control method proposed in the second aspect of this application.

[0015] In this embodiment, the control module determines the system operating mode by monitoring the real-time status of the step-up transformer on the grid side. When the grid is normal, the wind turbine generates electricity through the step-up transformer, prioritizing power supply to the grid. When a grid fault occurs or voltage fluctuations exceed a threshold, the system switches to off-grid mode, where the wind turbine, energy storage module, and diesel generator jointly supply power to the local load, avoiding the risk of power outages. The power demand in both grid-connected and off-grid modes is determined by simulating the load. Based on the power demand, the rationality of power allocation is verified, and the operating parameters of the distribution transformer are optimized to ensure a stable power supply to the load. In grid-connected mode, the control module adjusts the output power of the wind turbine according to the grid demand and the wind turbine's generating capacity, while simultaneously controlling the charging and discharging of the energy storage module to smooth out power fluctuations. In off-grid mode, the control module coordinates the output of the wind turbine, diesel generator, and energy storage module according to changes in the power load, ensuring a stable and reliable power supply.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a wind turbine grid-connected and off-grid control system provided in an embodiment of this application; Figure 2 This is a schematic diagram of another wind turbine grid-connected control system provided according to an embodiment of this application; Figure 3 This is a schematic diagram of another wind turbine grid-connected control system provided according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a control module according to an embodiment of this application; Figure 5 This is a schematic diagram of an off-network mode provided according to an embodiment of this application; Figure 6 This is a schematic diagram of a grid connection mode provided according to an embodiment of this application; Figure 7 A schematic flowchart illustrating a wind turbine grid connection / off-grid control method provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0018] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0019] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a” and “the” as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0020] It should be understood that although the terms first, second, third, etc., may be used to describe various information in the embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words "if" and "suppose" as used herein can be interpreted as "when," "when," or "in response to a determination."

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0022] Wind turbines are mainly divided into two operating modes: grid-connected mode and off-grid mode, depending on different application scenarios and needs, and each mode undertakes different tasks.

[0023] In grid-connected mode, wind turbines do not operate in isolation but require close synchronization with the power grid. The power grid has strict frequency and phase standards; only when wind turbines maintain a high degree of consistency with the grid in frequency and phase can smooth power transmission and efficient utilization be achieved, avoiding serious problems such as power oscillations and equipment damage caused by asynchrony. Simultaneously, grid-connected wind turbines must also possess fault ride-through capability. During operation, the power grid is inevitably affected by various internal and external factors, such as lightning strikes, short-circuit faults, and equipment aging, resulting in abnormal situations such as voltage drops and frequency fluctuations. In such cases, wind turbines cannot simply disconnect from the grid and shut down as under normal circumstances. Instead, they must maintain a certain power output within a specified time frame to continue supporting the grid, helping it to quickly restore normal operation and ensuring the stability and reliability of the entire power system.

[0024] In off-grid mode, wind turbines must independently support the loads. As the core energy source, wind turbines provide the necessary electrical energy to various connected loads. Because loads have stringent requirements for voltage and frequency stability, wind turbines need precise voltage and frequency regulation capabilities. Through preset control strategies and internal power electronics, wind turbines monitor and adjust their output parameters in real time to ensure that voltage and frequency remain stable within permissible ranges under various load variations, providing high-quality power to the loads.

[0025] However, the output power of wind turbines is affected by wind speed, which is inherently uncertain and random, resulting in strong intermittency and fluctuation in the output power of wind turbines. For example, when wind speed suddenly increases, the output power of a wind turbine rises rapidly; conversely, when wind speed decreases or gusts occur, the output power drops sharply. This unstable power output characteristic poses a significant challenge to the control of wind turbines in both grid-connected and off-grid modes. In grid-connected mode, power fluctuations may cause fluctuations in grid frequency and voltage, affecting power quality and even threatening the stable operation of the grid. In off-grid mode, intermittent power changes may lead to local voltage and frequency instability, failing to meet the normal load demands and thus affecting the reliable operation of the entire local power system.

[0026] Therefore, how to effectively address the intermittency and fluctuation of wind turbine output power and achieve stable and efficient control in grid-connected and off-grid modes has become a key issue that urgently needs to be addressed in the current wind power generation field.

[0027] The following description, with reference to the accompanying drawings, describes a wind turbine grid connection and off-grid control system and method according to embodiments of this application.

[0028] Figure 1This is a schematic diagram of the structure of a wind turbine grid-connected and off-grid control system provided in an embodiment of this application.

[0029] like Figure 1 As shown, the wind turbine grid-connected control system includes a wind turbine, converter, step-up transformer, distribution transformer, energy storage module, diesel generator set, electrical load, simulated load, and control module, wherein: like Figure 1 As shown, the converter of this wind turbine grid-connected control system includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the wind turbine and receives the AC power captured and converted by the wind turbine. The first output terminal of the converter is connected to the grid via a step-up transformer. In grid-connected mode, the electrical energy generated by the wind turbine is processed by the power electronic conversion inside the converter and then output from the first output terminal. The step-up transformer can boost the lower voltage level of the electrical energy output by the converter to a higher voltage level that matches the grid, thereby meeting the grid's requirements for power transmission and distribution. The second output terminal of the wind turbine is connected to the input terminal of a distribution transformer, forming a local power supply network. In this local power supply network, energy storage modules, diesel generator sets, electrical loads, and simulated loads are all connected to the output terminal of the distribution transformer.

[0030] It should be noted that the energy storage module has the ability to store and release electrical energy. When the wind turbine output power is excessive, it stores the excess electrical energy; when the wind turbine output power is insufficient or in off-grid mode, it releases the stored electrical energy to provide continuous and stable power support for the electrical load. This can smooth out the intermittency and fluctuation of the wind turbine output power, thereby improving the reliability and stability of power supply.

[0031] It should be noted that diesel generator sets are used to provide supplemental power. When wind turbines are unable to provide sufficient power due to insufficient wind speed or other reasons, and the energy storage module is nearly depleted, the diesel generator set can quickly start to provide the necessary power supplement to the electrical load, ensuring the normal operation of the local power system.

[0032] It should be noted that the simulated load can simulate electricity demand of different scales and characteristics, and by adjusting the size and characteristics of the simulated load, key indicators such as power quality, power distribution, and fault ride-through capability in grid-connected and off-grid modes can be tested and evaluated.

[0033] It should be noted that the distribution transformer is responsible for the reasonable allocation and regulation of the input electrical energy. According to the needs of different electrical loads, the electrical energy is distributed to each electrical device based on appropriate voltage levels and power, ensuring that each electrical load can obtain a stable and high-quality power supply.

[0034] like Figure 1As shown, the control module of the wind turbine grid-connected and off-grid control system is connected to the wind turbine, step-up transformer, distribution transformer, energy storage module, diesel generator set, electrical load, and simulated load. By monitoring the real-time status of the grid side of the step-up transformer, it determines whether the wind turbine is in grid-connected or off-grid mode, and controls the output power of the wind turbine and diesel generator set, the charging and discharging status of the energy storage module, the power distribution status of the distribution transformer, and the operating status of the electrical load and simulated load based on the determination result.

[0035] In one feasible implementation, the real-time status of the step-up transformer on the grid side includes voltage, frequency, phase, and power factor. By performing in-depth analysis and comprehensive judgment of the real-time status, the control module can determine whether the wind turbine should operate in grid-connected or off-grid mode. For example, if the voltage, frequency, phase, and power factor are all within preset threshold ranges, the control module determines that the wind turbine should operate in grid-connected mode; conversely, if a grid fault or abnormal fluctuation occurs, and any one of the voltage, frequency, phase, or power factor exceeds the preset threshold range, the control module determines and switches the wind turbine to off-grid mode to ensure the continuity of local power supply.

[0036] In one feasible implementation, the control module dynamically adjusts the output power of wind turbines and diesel generators based on factors such as current electricity demand, the status of energy storage modules, and the grid's capacity. In grid-connected mode, when wind speed is sufficient and the grid has adequate capacity, the control module instructs the wind turbines to operate in maximum power point tracking (MPPT) mode to maximize the utilization of clean energy. Simultaneously, if the diesel generators are already running, their output power is appropriately reduced to conserve fuel. In off-grid mode, the control module rationally allocates the output power of the wind turbines and diesel generators according to the size and priority of the electricity load to ensure a stable power supply to critical loads.

[0037] In one feasible implementation, for the energy storage module, in grid-connected mode, when the wind turbine output power is excessive, the control module will promptly control the energy storage module to charge and store the excess electrical energy; conversely, when the grid experiences power shortages or the wind turbine output power is insufficient, the control module will quickly activate the energy storage module's discharge function to provide supplementary electrical energy to the load, thus smoothing power fluctuations and improving power supply reliability. In off-grid mode, the control module will rationally arrange the charging and discharging process of the energy storage module according to the load demand and its own power availability, ensuring that the system can operate continuously for a period of time without external power support.

[0038] In one feasible implementation, for the distribution transformer, the control module precisely adjusts the output voltage and power distribution ratio of the distribution transformer according to the characteristics and demands of different power consumption areas and different power loads. For example, in industrial power consumption areas, the control module distributes higher voltage and greater power through the distribution transformer to meet the operational needs of large production equipment; in residential power consumption areas, the control module dynamically adjusts the output voltage and power of the distribution transformer according to the time patterns and load characteristics of residential electricity consumption to ensure normal electricity supply for residents.

[0039] In one feasible implementation, the control module dynamically controls the operating status of the electrical load and the simulated load based on the operating mode and timing requirements. In grid-connected mode, the control module prioritizes meeting the power supply needs of critical electrical loads while conducting relevant tests and adjustments based on the simulated load settings. In off-grid mode, the control module rationally allocates electrical energy based on the power supply capacity of the energy storage module and the diesel generator set to ensure the continuous operation of critical electrical loads, and makes corresponding adjustments and optimizations to the simulated load to simulate the power demand under different scenarios.

[0040] In one feasible implementation, the energy storage module includes at least one of battery energy storage, supercapacitor energy storage, and flywheel energy storage. Battery energy storage has the advantage of high energy density; supercapacitor energy storage has the advantages of high power density and fast charging and discharging speed; flywheel energy storage, as a physical energy storage method, has the advantages of long service life and simple maintenance. The configuration of the energy storage module should be selected according to the specific application scenario, which will not be elaborated here.

[0041] In one feasible implementation, the wind turbine grid-connected / off-grid control system can also be configured using the wind turbine, converter, step-up transformer, distribution transformer, energy storage module, electrical load, and control module. Figure 2 This is a schematic diagram of another wind turbine grid-connected / off-grid control system provided according to an embodiment of this application. Figure 2 Further details about each component can be found in the descriptions of the relevant content in the above embodiments, and will not be repeated here.

[0042] In one feasible implementation, the wind turbine grid-connected / off-grid control system can also be configured using wind turbines, converters, step-up transformers, distribution transformers, energy storage modules, electrical loads, diesel generator sets, photovoltaic generator sets, and control modules. Figure 3 This is a schematic diagram of another wind turbine grid-connected control system provided according to an embodiment of this application, wherein a photovoltaic generator can work in conjunction with the wind turbine to compensate for the power output shortfall during windless periods in the daytime. Regarding... Figure 3 Further details about each component can be found in the descriptions of the relevant content in the above embodiments, and will not be repeated here.

[0043] In one feasible implementation, Figure 4 This is a schematic diagram of the structure of a control module provided according to an embodiment of this application.

[0044] like Figure 4 As shown, the control module includes a data acquisition unit, a data processing unit, and an execution unit. The data acquisition unit is connected to the wind turbine, step-up transformer, distribution transformer, energy storage module, diesel generator set, electrical load, and simulated load, and is used to collect the real-time status of the grid side of the step-up transformer, as well as the operating parameters of the wind turbine, distribution transformer, energy storage module, diesel generator set, electrical load, and simulated load. The data processing unit is connected to the data acquisition unit and is used to process the real-time status and operating parameters, and determine the control strategy based on the processing results. The execution unit is connected to the data processing unit and is used to execute control actions according to the control strategy.

[0045] In some embodiments, for the grid side of the step-up transformer, the data acquisition unit collects key parameters such as voltage, frequency, phase, and power factor. Voltage parameters reflect the power supply level of the grid, and their fluctuation range directly affects the safe operation of electrical equipment; frequency parameters reflect the synchronicity of the grid, and frequency stability is crucial for maintaining the power balance of the system; phase parameters are closely related to power quality and transmission efficiency; and the power factor reflects the ratio of active power to apparent power in the grid and is used to evaluate the operating efficiency of the grid.

[0046] In some embodiments, for wind turbine generators, the data acquisition unit collects parameters such as output power, rotational speed, pitch angle, and wind speed. Output power reflects the power generation capacity of the wind turbine generator; rotational speed and pitch angle reflect key factors in the efficiency and stability of the wind turbine generator; wind speed is used to reflect the power generation output of the wind turbine generator.

[0047] In some embodiments, for distribution transformers, the data acquisition unit collects data such as load rate, temperature, and oil level. The load rate reflects the load level of the distribution transformer, while temperature and oil level are used to assess the transformer's operating status and safety.

[0048] In some embodiments, for an energy storage module, the data acquisition unit collects charging and discharging current, voltage, remaining power, number of charging and discharging cycles, etc. These parameters can reflect the charging and discharging status and health status of the energy storage module.

[0049] In some embodiments, for a diesel generator set, the data acquisition unit collects data such as output power, fuel consumption rate, speed, and oil pressure. Output power and fuel consumption rate reflect the power generation efficiency and economic indicators of the diesel generator set, while speed and oil pressure reflect whether the diesel generator set can operate normally.

[0050] In some embodiments, for electrical loads, the data acquisition unit collects power demand, electricity consumption, power factor, etc. Power demand and electricity consumption are used to reflect the size of the load and the electricity consumption trend, while the power factor is used to reflect the power quality of the load.

[0051] In some embodiments, for simulated loads, the data acquisition unit collects set parameters, operating status, simulated load, etc. These parameters are used to simulate power loads under different scenarios, providing convenience for testing and debugging.

[0052] In some embodiments, the data processing unit preprocesses the data collected by the data acquisition unit. Based on the preprocessed data, the data processing unit analyzes the grid-side parameters of the step-up transformer and combines them with historical data to determine the grid's operating mode (grid-connected or off-grid) and its stability and reliability. By analyzing the correlation between wind turbine speed, pitch angle, and output power, mechanical or electrical faults in the wind turbine can be detected. By monitoring the charging and discharging current and voltage of the energy storage module, it is possible to determine whether the charging and discharging status of the energy storage module is normal and whether there are problems such as overcharging or over-discharging.

[0053] In some embodiments, the data processing unit formulates corresponding control strategies based on the judgment results. In grid-connected mode, when the grid voltage fluctuates significantly, the data processing unit formulates a control strategy to adjust the reactive power output of the wind turbine to stabilize the grid voltage. In off-grid mode, when the electrical load suddenly increases, the data processing unit formulates a control strategy to start the diesel generator or adjust the discharge power of the energy storage module to meet the load's electricity demand. The data output unit formulates preventative control strategies based on the operating parameters of the electrical load and the simulated load to avoid potential faults.

[0054] In some embodiments, the execution unit establishes a control interface with the wind turbine, energy storage module, and diesel generator set by controlling actuators such as relays, circuit breakers, frequency converters, and contactors. Relays and circuit breakers are used to control the on / off state of the circuit, realizing the start-up and shutdown control of the equipment; frequency converters are used to adjust the operating frequency and speed of the equipment, realizing precise control of the output power of the equipment; and contactors are used to switch the circuit connection mode to meet the needs of different operating modes.

[0055] In some embodiments, when the control strategy of the data processing unit indicates an increase in the output power of the wind turbine, the execution unit adjusts the speed and pitch angle of the wind turbine by controlling the frequency converter, so that its output power increases according to predetermined requirements. When the control strategy of the data processing unit indicates that the energy storage module needs to be charged, the execution unit controls the on / off state of the charging circuit and the magnitude of the charging current to ensure that the energy storage module is charged safely and efficiently.

[0056] In one feasible implementation, the wind turbine grid connection and off-grid control system of this application embodiment further includes a protection module, which is connected to the wind turbine, converter, step-up transformer, distribution transformer, energy storage module and diesel generator for fault protection.

[0057] In some embodiments, if the protection module detects that the vibration amplitude of the wind turbine exceeds a preset safety threshold or that the rotational speed fluctuates abnormally, it determines that there may be a mechanical fault in the wind turbine and immediately triggers protection actions, such as shutdown protection, to prevent the fault from escalating further.

[0058] For example, when the protection module detects that the vibration amplitude of the wind turbine exceeds a preset safety threshold, it often indicates that one or more mechanical components of the turbine may have experienced abnormal conditions such as loosening, wear, or breakage, leading to increased vibration. For example, if the rotational speed fluctuates abnormally, such as a sudden increase or decrease exceeding the normal operating range, this could be due to rotor imbalance, gearbox failure, generator failure, or other reasons. In either of these cases, the protection module will quickly determine that the wind turbine may have a mechanical fault based on its built-in intelligent algorithm and fault diagnosis logic.

[0059] For example, when the protection module determines a fault, it will immediately trigger a protection action. The protection module will trigger a shutdown protection, which will quickly cut off the power input to the unit, causing the wind turbine to stop rotating. This prevents further damage to the faulty component under high-speed operation, thereby preventing the fault from spreading and protecting the structural integrity of the entire wind turbine and other normal components from being affected.

[0060] For example, the protection module will also upload fault information to the monitoring center in a timely manner, providing maintenance personnel with detailed fault data and diagnostic results so that they can quickly locate the fault, formulate reasonable maintenance plans, shorten maintenance time, and improve the availability of wind turbine units.

[0061] In some embodiments, the protection module monitors parameters such as the transformer's input and output current, voltage, and power. When the converter experiences faults such as overcurrent, overvoltage, undervoltage, or overtemperature, the protection module issues an alarm and takes corresponding protective measures based on the severity of the fault. For example, for minor overcurrent faults, the protection module may adjust the converter's control strategy to reduce output power and eliminate the overcurrent. For severe faults, such as short-circuit faults, the protection module will quickly cut off the converter's power supply to prevent the fault from spreading and protect the converter and other related equipment.

[0062] In some embodiments, the protection module monitors the charging and discharging process of the energy storage module. During charging, the protection module monitors parameters such as charging current, voltage, and battery temperature in real time to prevent overcharging. When the charging current or voltage exceeds the battery's safe charging range, or the battery temperature becomes too high, the protection module immediately stops charging and protects the battery to prevent damage from overcharging and extend its lifespan. During discharging, the protection module monitors the discharging current and remaining battery capacity to prevent over-discharging. When the discharging current is too high or the remaining battery capacity is too low, the protection module limits the discharging power or stops discharging to protect the battery's safety.

[0063] For example, during charging, the protection module uses current sensors, voltage sensors, and temperature sensors to continuously collect and monitor key parameters such as charging current, voltage, and battery temperature in real time. These sensors can accurately capture minute changes in these parameters. Internally, the protection module uses a preset safe charging range that matches the battery's characteristics (this range is based on the battery's chemical properties, design parameters, and multiple experimental verifications). When the charging current or voltage exceeds this safe range, it indicates that the battery may face overcharging risk. Overcharging can lead to electrolyte decomposition, electrode material structure damage, and consequently, serious consequences such as battery swelling, leakage, or even explosion.

[0064] For example, if the battery temperature is too high, exceeding the normal operating temperature range, it will accelerate the internal chemical reaction of the battery, exacerbate battery aging, and reduce battery performance and lifespan. Once the protection module detects the above-mentioned abnormal situation, it will immediately trigger the protection mechanism, quickly cut off the charging circuit, stop the charging process, and take necessary protective measures for the battery, such as activating the heat dissipation system to reduce the battery temperature and prevent the battery from being damaged due to overcharging.

[0065] For example, during the discharge process, the protection module continuously monitors parameters such as the discharge current and the remaining battery capacity. Excessive discharge current generates excessive heat inside the battery, leading to increased battery temperature, accelerated battery aging, and potentially causing safety issues such as short circuits. Continuing to discharge when the remaining battery capacity is too low will cause the battery to enter a deep discharge state, severely damaging the battery's electrode materials and affecting its capacity recovery and cycle life. Based on preset safety thresholds, the protection module takes protective actions when it detects excessive discharge current or excessively low remaining battery capacity.

[0066] For example, in cases of excessive discharge current, the protection module will limit the discharge power and reduce the current by adjusting the power devices in the discharge circuit. When the remaining battery charge falls below the safety limit, the protection module will decisively disconnect the discharge circuit and stop the discharge, ensuring battery safety. These protective measures effectively extend battery life and improve the reliability and stability of the energy storage system.

[0067] In some embodiments, the protection module comprehensively monitors and protects the diesel generator during startup, operation, and shutdown. During startup, the protection module monitors parameters such as starting current and speed to ensure a smooth start. If startup failure or excessive starting current occurs, the protection module will issue an alarm and take measures such as restarting or switching to another backup power source. During operation, the protection module monitors parameters such as output power, voltage, frequency, oil pressure, and water temperature of the diesel generator in real time. When abnormal parameters are detected, the protection module adjusts the operating status of the diesel generator or issues an alarm signal to prevent damage due to faults. During shutdown, the protection module monitors parameters such as shutdown speed and cooling time to ensure safe shutdown.

[0068] For example, during the start-up phase of a diesel generator, the protection module uses current and speed sensors to collect key parameters such as starting current and speed in real time and dynamically. When the protection module detects excessive starting current, it will immediately issue an alarm signal to alert the operator.

[0069] For example, according to a preset protection strategy, the protection module can restart the diesel generator to eliminate temporary faults. If the restart fails, the protection module will quickly switch to other backup power sources to ensure the continuity of power supply and avoid power outages to critical loads caused by diesel generator startup failure.

[0070] It should be noted that starting current sensors typically employ the Hall effect principle, accurately measuring the current in the circuit at the moment of startup and converting it into a standard electrical signal for transmission to the protection module. Speed ​​sensors, on the other hand, often use magnetoelectric or photoelectric sensors, accurately acquiring speed information by detecting the rotational signal of the diesel generator flywheel or crankshaft.

[0071] It should be noted that engine speed is also a monitoring indicator during the startup process. If the diesel generator fails to reach the normal starting speed during startup, it may indicate insufficient fuel supply, ignition system malfunction, or abnormal compression ratio. The protection module analyzes the speed change trend in real time, and takes appropriate measures promptly upon detecting any abnormalities to ensure a smooth startup process.

[0072] As an example, Figure 5 This is a schematic diagram of an off-grid mode provided according to an embodiment of this application. Figure 5As shown, when the wind turbine is in off-grid operation, the connection between the distribution transformer and the step-up transformer is disconnected. The control module determines whether the diesel generator set and the simulated load are put into operation based on the actual output of the wind turbine, and determines the charging and discharging status of the energy storage module to ensure stable power load.

[0073] As an example, Figure 6 This is a schematic diagram of a grid connection mode provided according to an embodiment of this application. Figure 6 As shown, when the wind turbine receives the grid connection command, it establishes a connection between the step-up transformer and the distribution transformer, while the diesel generator set and the simulated load are not put into operation. The control module determines the charging and discharging mode of the energy storage module according to the specific output of the wind turbine to ensure stable power load.

[0074] It should be added that the control module of the wind turbine grid-connected control system provided in this application embodiment can also adopt an application-specific integrated circuit (ASIC, which is an integrated circuit with proprietary application programs designed and manufactured for specific user requirements and specific systems) or an intellectual property (IP) core. An IP core is a mature design of a circuit module with independent functions in chip or integrated circuit design. This circuit design can be applied to other chip or integrated circuit design projects that include this circuit module, thereby reducing the design workload, shortening the design cycle, and improving the success rate of chip or integrated circuit design. IP cores are classified into three levels: behavioral, structural, and physical, thus corresponding to three types of IP cores. These can be configured in various ways, such as soft cores designed with hardware description languages, solid cores that have completed structural descriptions, and hard cores that are based on physical descriptions and have been verified by processes. The specific configuration methods will not be elaborated here. As long as the real-time status of the step-up transformer on the grid side can be monitored to determine whether the wind turbine is in grid-connected or off-grid mode, and the output power of the wind turbine and the diesel generator set, the charging and discharging status of the energy storage module, the power distribution status of the distribution transformer, and the operating status of the electrical load and simulated load can be controlled according to the determination results, any configuration method of the control module is applicable and is not limited to this embodiment.

[0075] In summary, the wind turbine grid-connected / off-grid control system provided in this application determines the system's operating mode by monitoring the real-time status of the step-up transformer on the grid side. When the grid is normal, the wind turbine generates electricity through the step-up transformer, prioritizing power supply to the grid. When a grid fault occurs or voltage fluctuations exceed a threshold, the system switches to off-grid mode, where the wind turbine, energy storage module, and diesel generator jointly supply power to the local load, avoiding the risk of power outages. The system determines the electricity demand in both grid-connected and off-grid modes by simulating load conditions, verifies the rationality of power allocation based on demand, optimizes the operating parameters of the distribution transformer, and ensures stable power supply to the load. In grid-connected mode, the control module adjusts the output power of the wind turbine based on grid demand and the wind turbine's generating capacity, while simultaneously controlling the charging and discharging of the energy storage module to smooth out power fluctuations. In off-grid mode, the control module coordinates the output of the wind turbine, diesel generator, and energy storage module based on changes in load, ensuring a stable and reliable power supply.

[0076] Figure 7 This is a flowchart illustrating a wind turbine grid connection / off-grid control method provided in an embodiment of this application.

[0077] like Figure 7 As shown, the wind turbine grid connection and disconnection control method is applicable to the wind turbine grid connection and disconnection control system provided in the embodiments of this application. The wind turbine grid connection and disconnection control method includes, but is not limited to, the following steps: S701 acquires real-time operating data of the step-up transformer on the grid side.

[0078] For further details on step S701, please refer to the relevant descriptions in the above embodiments, which will not be repeated here.

[0079] S702 determines whether the wind turbine will operate in grid-connected or off-grid mode based on real-time operating data.

[0080] For further details on step S702, please refer to the relevant descriptions in the above embodiments, which will not be repeated here.

[0081] S703 controls the output power of wind turbines and diesel generators, the charging and discharging status of energy storage modules, the power distribution status of distribution transformers, and the operating status of electrical loads and simulated loads based on the judgment results.

[0082] In one feasible implementation, if the wind turbine is in grid-connected mode, the wind turbine is controlled to operate in maximum power point tracking mode, and the energy storage module is controlled to charge or discharge according to the power demand in grid-connected mode and the remaining power of the energy storage module; if the wind turbine is in off-grid mode, the diesel generator is controlled to start to provide supplementary power to the electrical load and simulated load, and the output power of the wind turbine and the diesel generator is allocated according to the power demand in off-grid mode and the remaining power of the energy storage module.

[0083] For further details on step S703, please refer to the relevant descriptions in the above embodiments; they will not be repeated here.

[0084] The wind turbine grid-connected / off-grid control method provided in this application determines the system's operating mode by monitoring the real-time status of the grid side of the step-up transformer through a control module. When the grid is normal, the wind turbine generates electricity through the step-up transformer, prioritizing power supply to the grid. When a grid fault occurs or voltage fluctuations exceed a threshold, the system switches to off-grid mode, where the wind turbine, energy storage module, and diesel generator jointly supply power to the local load, avoiding the risk of power outages. The system determines the electricity demand in both grid-connected and off-grid modes by simulating load conditions, verifies the rationality of power allocation based on the demand, optimizes the operating parameters of the distribution transformer, and ensures stable power supply to the load. In grid-connected mode, the control module adjusts the output power of the wind turbine according to the grid demand and the wind turbine's generating capacity, while simultaneously controlling the charging and discharging of the energy storage module to smooth out power fluctuations. In off-grid mode, the control module coordinates the output of the wind turbine, diesel generator, and energy storage module according to changes in the electricity load, ensuring a stable and reliable power supply.

[0085] Figure 8 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Figure 8 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0086] like Figure 8 As shown, the electronic device 800 includes a processor 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from memory 806 into a random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the electronic device 800. The processor 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0087] The following components are connected to I / O interface 805: memory 806 including hard disk; and communication section 807 including network interface card such as LAN (Local Area Network) card, modem, etc., communication section 807 performs communication processing via a network such as the Internet; driver 808 is also connected to I / O interface 805 as needed.

[0088] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 807. When the computer program is executed by processor 801, it performs the functions defined in the methods of this application.

[0089] In an exemplary embodiment, a storage medium including instructions is also provided, such as a memory including instructions, which can be executed by a processor 801 of an electronic device 800 to perform the above-described method. Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0090] In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can transmit, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wireline, optical fiber, RF, etc., or any suitable combination thereof.

[0091] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0092] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A wind turbine grid-connected / off-grid control system, characterized in that, This includes wind turbine generators, converters, step-up transformers, distribution transformers, energy storage modules, diesel generator sets, electrical loads, simulated loads, and control modules, among which: The converter includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the wind turbine generator set, the first output terminal is connected to the power grid via the step-up transformer, and the second output terminal is connected to the input terminal of the distribution transformer. The energy storage module, the diesel generator set, the electrical load, and the simulated load are all connected to the output terminal of the distribution transformer. The diesel generator set is used to provide supplementary power, the simulated load is used to test the power demand in grid-connected and off-grid modes, and the distribution transformer is used for power distribution. The control module is connected to the wind turbine, the step-up transformer, the distribution transformer, the energy storage module, the diesel generator set, the electrical load, and the simulated load. It determines whether the wind turbine is in grid-connected or off-grid mode by monitoring the real-time status of the grid side of the step-up transformer, and controls the output power of the wind turbine and the diesel generator set, the charging and discharging status of the energy storage module, the power distribution status of the distribution transformer, and the operating status of the electrical load and the simulated load based on the determination result.

2. The wind turbine grid-connected / off-grid control system according to claim 1, characterized in that, The real-time status of the step-up transformer on the grid side includes voltage, frequency, phase, and power factor.

3. The wind turbine grid-connected / off-grid control system according to claim 2, characterized in that, If the voltage, frequency, phase, and power factor are all within the preset threshold range, the wind turbine is determined to be in grid-connected mode; if any one of the voltage, frequency, phase, and power factor exceeds the preset threshold range, the wind turbine is determined to be in off-grid mode.

4. The wind turbine grid-connected / off-grid control system according to claim 3, characterized in that, If the wind turbine is in grid-connected mode, the control module controls the wind turbine to operate in maximum power point tracking mode, and controls the energy storage module to charge or discharge according to the power demand in grid-connected mode and the remaining power of the energy storage module.

5. The wind turbine grid-connected / off-grid control system according to claim 3, characterized in that, If the wind turbine is in off-grid mode, the control module controls the diesel generator to start and provide supplementary power to the electrical load, and allocates the output power of the wind turbine and the diesel generator according to the power demand in off-grid mode and the remaining power of the energy storage module.

6. The wind turbine grid-connected / off-grid control system according to claim 1, characterized in that, The energy storage module includes at least one of battery energy storage, supercapacitor energy storage, and flywheel energy storage.

7. The wind turbine grid-connected / off-grid control system according to claim 1, characterized in that, The control module includes a data acquisition unit, a data processing unit, and an execution unit. The data acquisition unit is connected to the wind turbine, the step-up transformer, the distribution transformer, the energy storage module, the diesel generator set, the electrical load, and the simulated load. It is used to acquire the real-time status of the step-up transformer on the grid side, as well as the operating parameters of the wind turbine, distribution transformer, energy storage module, diesel generator set, electrical load, and simulated load. The data processing unit is connected to the data acquisition unit and is used to process the real-time status and operating parameters, and determine the control strategy based on the processing results. The execution unit is connected to the data processing unit and is used to execute control actions according to the control strategy.

8. The wind turbine grid-connected / off-grid control system according to claim 1, characterized in that, Also includes: The protection module is connected to the wind turbine, the converter, the step-up transformer, the distribution transformer, the energy storage module, and the diesel generator for fault protection.

9. A method for controlling the grid connection and disconnection of wind turbine generators, applicable to the grid connection and disconnection control system of wind turbine generators as described in any one of claims 1 to 8, characterized in that, include: Obtain real-time operating data of the step-up transformer on the grid side; The wind turbine is determined to be either in grid-connected or off-grid mode based on the real-time operating data. Based on the judgment results, the output power of wind turbines and diesel generators, the charging and discharging status of energy storage modules, the power distribution status of distribution transformers, and the operating status of electrical loads and simulated loads are controlled.

10. The wind turbine grid connection / off-grid control method according to claim 9, characterized in that, include: If the wind turbine is in grid-connected mode, control the wind turbine to operate in maximum power point tracking mode, and control the energy storage module to charge or discharge according to the power demand in grid-connected mode and the remaining power of the energy storage module. If the wind turbine is in off-grid mode, the diesel generator set is controlled to start and provide supplementary power to the electrical load and simulated load. The output power of the wind turbine and diesel generator set is allocated according to the power demand in off-grid mode and the remaining power of the energy storage module.

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