Anti-islanding low-voltage fan grid-connected control unit system and hardware

Abstract

The invention provides an anti-islanding low-voltage fan grid-connected control unit system and hardware, and relates to the technical field of fan power generation, the system structure is composed of a fan generator set, a sensing layer, a processing layer and an application layer, and the corresponding hardware structure in the system comprises an equipment frame where the system is located and a plurality of fan generator sets. A grid-connected model of the fan generator set is built through application layer setting in the system, analog simulation training is carried out by setting various parameters of various structures of the fan generator set, and the parameters are displayed, so that a user can comprehensively understand the relationship among various parameter units of the fan generator set, and the user experience is improved. And simulation parameters are stored through simulation training to form a database, so that when a corresponding parameter structure is generated for an actual fan generator set, rapid response processing is carried out, fan grid connection detection is conveniently added, and safety and model simulation training teaching use are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine power generation, and in particular to an anti-islanding low-pressure wind turbine grid-connected control unit system and hardware. Background Art

[0002] The economic value of wind power generation is comparable to that of natural gas power generation, and it is a relatively cheap renewable energy source today. The active power output of wind turbines is still limited by wind speed, and wind speed is related to factors such as season and weather. Therefore, the output power of wind turbines cannot be maintained stable, which in turn affects the power quality of wind power grid connection points. With the continuous increase in wind power installed capacity, the voltage quality problem at the grid connection points will become more and more prominent. In severe cases, voltage collapse may even occur, posing a huge safety hazard to the stable operation of the power grid.

[0003] According to a multi-phase wind turbine DC grid-connected system and its low voltage ride-through control method disclosed in Chinese patent number "CN113315114B", the method controls the operation of the switch element of the isolation conversion module by a first trigger pulse signal, and controls the operation of the switch element of the half-bridge module by a second trigger pulse signal, so that the multi-phase wind turbine DC grid-connected system can achieve low voltage ride-through DC grid-connected. The low voltage ride-through control method of the multi-phase wind turbine DC grid-connected system realizes the maximum power tracking of the generator motor side by the outer loop control of the speed of the generator motor, and realizes the DC grid-connected low voltage ride-through control by summarizing the average value of the capacitor voltage of the half-bridge sub-module in the half-bridge module when a fault occurs by tracking. No auxiliary equipment is required to achieve low voltage ride-through, and the stability of the multi-phase wind turbine DC grid-connected system is also improved, which solves the technical problem that the existing multi-phase wind turbine DC grid-connected system uses three-phase wind turbine DC grid-connected to achieve low voltage ride-through with the help of auxiliary equipment, and increases the construction of the multi-phase wind turbine DC grid-connected system.

[0004] The above patent documents and prior art have the following technical problems when used:

[0005] Problem 1: In the above patent documents and prior art, when multiple wind turbines are connected to the power generation system, the voltage stability of the grid-connected system cannot be stably compensated, resulting in the problem of unstable grid voltage;

[0006] Problem 2: When multiple wind turbines are connected to the grid, the above document fails to monitor the wind turbine parameters in a targeted manner, resulting in the inability to timely warn and handle abnormal conditions of wind turbine power generation equipment, which is not safe.

[0007] Problem three: For the grid-connected system, it is impossible to build a simulation training structure based on the grid connection, which results in the system being unable to provide assistance in simulation teaching. At the same time, it is impossible to prepare in advance and respond quickly to changes in different parameters of the wind turbine. Summary of the invention

[0008] Technical issues solved

[0009] In view of the shortcomings of the prior art, the present invention provides an anti-islanding low-pressure fan grid-connected control unit system and hardware, which solves the following problems:

[0010] 1. The voltage stability of multiple wind turbines connected to the grid is insufficient, and voltage compensation cannot be performed;

[0011] 2. When multiple groups of fans are connected to the grid, it is impossible to collect multiple parameters of the fans, resulting in the inability to handle emergencies in a timely manner;

[0012] 3. The wind turbine grid-connected system is not operable and teachable enough to provide parameter basis and rapid response data support for wind turbine emergency situations.

[0013] Technical Solution

[0014] To achieve the above objectives, the present invention is implemented through the following technical solutions: an anti-islanding low-pressure wind turbine grid-connected control unit system and hardware, the system structure consists of a wind turbine generator set, a perception layer, a processing layer and an application layer, and the corresponding hardware structure in the system includes a device framework where the system is located and multiple groups of wind turbine generator sets, wherein,

[0015] The perception layer is connected to the external wind turbine generator set. It uses multiple sets of phasor measurement devices to accurately record and save the steady-state and dynamic processes of the power signals and electrical quantities of each measuring point of the multiple sets of generator sets in real time, so as to provide a data basis for monitoring and early warning of the wind turbine generator set grid connection.

[0016] The processing layer receives the monitoring data from the perception layer, centrally aggregates the data obtained by multiple phasor measurement devices through the internal phasor data collector, and electronically synchronizes the connection structure of the wind turbine generator set in real time;

[0017] The application layer is used for display, early warning, emergency response, power grid storage and simulation training of the entire system. The application layer performs online analysis of the synchronous oscillation mode of the data transmitted by the processing layer, and can display the sub-synchronous oscillation mode parameters and related early warning information on the system interface based on the analysis results of the measured data;

[0018] The wind turbine generator set provides the wind power grid-connected foundation for the entire system framework. It adopts a wind turbine system structure that combines a doubly-fed wind turbine with a dual PWM converter, and adds a static VAR generator at the wind turbine generator set grid-connected point to perform reactive power compensation for the wind turbine generator set.

[0019] Preferably, the wind turbine generator set is composed of blades, a wind turbine, a gearbox, a double-fed wind turbine, a dual PWM converter, a filter, a static VAR generator and other control systems, wherein:

[0020] The dual PWM converter is divided into a rotor-side converter and a grid-side converter, and a static VAR generator is connected between the rotor-side converter and the grid-side converter;

[0021] The static VAR generator receives the reactive current in the system, detects it, generates a PWM pulse signal, and outputs the corresponding total compensation current to manage the reactive power shortage of the power grid.

[0022] Preferably, the perception layer collects parameters of the wind turbine generator set including current, voltage, frequency, load, wind speed, stability, and fluctuation, and each group of wind turbine generator sets is numbered in digital sequence, and the number and order of phasor measurement devices correspond one-to-one to the wind turbine generator set.

[0023] Preferably, the application layer further includes:

[0024] The early warning module stores the data calculation model of the wind turbine generator set, stores the corresponding data of the changes between the parameters through the calculation model, compares the data of the actual wind turbine generator set, and issues a timely early warning when it exceeds a certain threshold;

[0025] Display module, which displays the warning parameters and simulation training parameters in the system, and controls the simulation training parameters by touch;

[0026] The storage module is used to store the grid-connected electric energy of the wind turbine generator set, and is internally provided with filters, voltage regulating equipment, and voltage stabilizing equipment to output the grid electric energy in a stable voltage;

[0027] The simulation training module is used to display and control the electronic structure of multiple wind turbine generator sets, and to change the corresponding current, voltage, wind speed and other control parameters through the display module, to simulate the actual grid-connected framework structure, and to store the simulation data to assist in the comparison and adjustment of the actual parameters of the wind turbine generator sets.

[0028] Preferably, the processing layer performs signal type analysis in the grid-connected system based on the parameter information of the wind turbine generator set in the perception layer, which are free oscillation corresponding signals and random corresponding signals, and the free oscillation corresponding signals at least include circuit breaking, line breaking and instantaneous unit grid connection, and the random corresponding signals at least include random fluctuations in energy output and load switching.

[0029] Preferably, the system accommodates the hardware of the entire perception layer, processing layer and application layer through an external frame cabinet structure, and collects, processes, analyzes and warns data after being connected to multiple external wind turbine generator sets through grid-connected lines, forming the hardware structure of the entire wind turbine grid-connected system.

[0030] Preferably, the grid-side converter inside the wind turbine generator set is used to provide stability of the bus voltage and stability of the rotor-side converter. The rotor-side converter controls the power and no power and rotor speed of the stator side of the doubly fed wind turbine by adjusting the current, and is used for coordination with the wind turbine.

[0031] Beneficial Effects

[0032] The present invention provides an anti-islanding low-pressure fan grid-connected control unit system and hardware. It has the following beneficial effects:

[0033] 1. The present invention adopts multiple groups of wind turbine generator sets to cooperate with the perception layer, processing layer and application layer to form the framework structure and hardware structure of the entire wind turbine grid-connected system, so that the system can collect, store, analyze and process data of multiple groups of wind turbine generator sets through the perception layer and the processing layer, and calculate the oscillation stability of each group of wind turbines and the numerical value of each parameter through the application layer and compare them with the existing stable database structure, so as to realize timely early warning and emergency processing of abnormal conditions of wind turbine generator sets, with high safety and stability, and convenient for automatic detection and protection of system faults.

[0034] 2. The present invention adopts a doubly-fed wind turbine in conjunction with a dual PWM converter to form the entire wind turbine power generation structure, and adds a static reactive generator at the wind turbine generator set grid-connected point to perform reactive power compensation for the wind turbine generator set. Compared with the existing connection structure directly connected to the DC voltage, the static reactive generator can not only achieve rapid tracking and control of the reactive power of the power grid and maintain the stability of the power grid voltage in real time, but also has the functions of suppressing negative sequence current, reducing the system harmonic distortion rate, and automatically managing the three-phase load imbalance problem of the system, thereby improving the stability of the wind turbine grid-connected system and reducing fluctuations.

[0035] 3. The present invention adopts the system's internal application layer to set up a model for the grid-connected wind turbine generator set, and performs simulation training by setting various parameters of various structures of the wind turbine generator set, and displays them, so that users can fully understand the relationship between various parameter sets of the wind turbine generator set, and store the simulation parameters through simulation training to form a database, which is convenient for rapid response processing when generating corresponding parameter structures for actual wind turbine generator sets, which is convenient for increasing the detection of wind turbine grid connection, improving safety and model simulation training and teaching use. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a system connection structure diagram of the present invention;

[0037] Figure 2 It is a reactive power compensation capacity calculation module diagram of the present invention;

[0038] Figure 3 It is a grid-connected simulation wiring diagram of a wind turbine generator set of the present invention;

[0039] Figure 4 This is the application layer control structure diagram of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Specific embodiment one:

[0042] like Figure 1-4 As shown, the anti-islanding low-pressure wind turbine grid-connected control unit system and hardware, the system structure consists of a wind turbine generator set, a perception layer, a processing layer and an application layer, and the corresponding hardware structure in the system includes the device framework where the system is located and multiple wind turbine generator sets, among which,

[0043] The perception layer is connected to the external wind turbine generator set. It uses multiple sets of phasor measurement devices to accurately record and save the steady-state and dynamic processes of the power signals and electrical quantities of each measuring point of the multiple sets of generator sets in real time, so as to provide a data basis for monitoring and early warning of the wind turbine generator set grid connection.

[0044] The processing layer receives the monitoring data from the perception layer, centrally aggregates the data obtained by multiple phasor measurement devices through the internal phasor data collector, and electronically synchronizes the connection structure of the wind turbine generator set in real time;

[0045] The application layer is used for display, early warning, emergency response, power grid storage and simulation training of the entire system. The application layer performs online analysis of the synchronous oscillation mode of the data transmitted by the processing layer, and can display the sub-synchronous oscillation mode parameters and related early warning information on the system interface based on the analysis results of the measured data;

[0046] The wind turbine generator set provides the wind power grid-connected foundation for the entire system framework. It adopts a wind turbine system structure that combines a doubly-fed wind turbine with a dual PWM converter, and adds a static VAR generator at the wind turbine generator set grid-connected point to perform reactive power compensation for the wind turbine generator set.

[0047] In the system, the hardware of the entire perception layer, processing layer and application layer is accommodated through an external frame cabinet structure, and data collection, processing, analysis and early warning are carried out after being connected to multiple external wind turbine generator sets through grid-connected lines, forming the hardware structure of the entire wind turbine grid-connected. The system adopts the internal application layer to set up a model of wind turbine generator grid-connected, and simulates and trains various parameters of various structures of wind turbine generator sets, and displays them, so that users can fully understand the relationship between various parameter sets of wind turbine generator sets, and store simulation parameters through simulation training to form a database, so as to generate corresponding parameter structures for actual wind turbine generator sets. Rapid response processing is carried out, which is convenient for increasing the detection of wind turbine grid-connected, improving safety and model simulation training and teaching use. Specific embodiment 2:

[0049] like Figure 1-4 As shown, the wind turbine generator set consists of blades, wind turbines, gearboxes, double-fed wind turbines, dual PWM converters, filters, static VAR generators and other control systems, among which:

[0050] The dual PWM converter is divided into a rotor-side converter and a grid-side converter, and a static VAR generator is connected between the rotor-side converter and the grid-side converter;

[0051] The static VAR generator receives the reactive current in the system, detects it, generates a PWM pulse signal, and outputs the corresponding total compensation current to manage the reactive power shortage of the power grid.

[0052] The grid-side converter inside the wind turbine generator set is used to provide stability for the bus voltage and the rotor-side converter. The rotor-side converter controls the power and rotor speed on the stator side of the doubly-fed wind turbine by adjusting the current, and is used for coordination with the wind turbine.

[0053] When adjusting the voltage and reactive power of a wind farm, it is necessary to pre-set the reference value of the wind farm grid connection point voltage and set the expected grid connection point voltage value as U pcc_r , and the voltage is calculated according to the standard value. If the measured data of the voltage at the wind farm grid connection point is U pcc ∈[U pcc -0.05, U pcc +0.05], it means that the voltage at the wind farm grid connection point is qualified; if the voltage at the wind farm grid connection point is not within this range, the voltage needs to be adjusted to make it at a qualified level. The voltage deviation is defined as:

[0054] ΔU pcc =U pcc -U pcc_r

[0055] When the absolute value of the voltage deviation is greater than 0.05, the grid connection point voltage quality is unqualified, and reactive power compensation is required to improve the grid connection point voltage. Priority is given to driving SVG, that is, the static reactive power generator injects reactive power into the system. However, the reactive power capacity of SVG should have a certain margin to cope with problems such as system voltage drop under unexpected conditions, and the state of SVG is KSVG, which is expressed as follows:

[0056]

[0057] Where: Q SVG is the reactive power actually generated by SVG, Q SVGmax is the maximum capacity of SVG, K SVG =1 means that the SVG reactive power output has been fully generated. At this time, the remaining reactive power shortage of the system needs to be provided by the double-fed wind turbine to improve the voltage qualification rate of the grid connection point. In order to reasonably distribute the reactive power output of each wind turbine, it is assumed that each unit outputs reactive power according to the principle of equal power factor. The reactive power output of the wind turbine is adjusted according to the actual measured value of the unit's active power. The reactive power adjustment expression is as follows:

[0058]

[0059] Where: i is the number of the wind turbine;

[0060] Indicates the reactive power output value of the i-th fan;

[0061] Q DFIG_r Indicates the total reactive output value of the wind turbine;

[0062] P DFIG_mi Represents the active output of unit i.

[0063] When performing reactive power compensation on the wind farm grid-connected system, it is necessary to clarify the reactive power shortage of the system. The reactive power shortage of the system can be obtained by starting with the voltage deviation at the grid-connected point, and converting the node deviation into reactive power shortage through the proportional integral link, such as Figure 2 The calculation block diagram shown in the figure, where DFIG is a doubly fed wind turbine. In order to adjust the voltage at the wind power grid connection point to within the qualified range, the measured voltage value at the grid connection point is subtracted from the reference value, and the steady-state static error is eliminated through PI control, and a dead zone is set to prevent the equipment from operating too frequently, thereby obtaining the total reactive power shortage of the system.

[0064] like Figure 3 As shown in the figure, it is a simulation connection diagram of multiple wind turbine generator sets connected to the grid with SVG. Among them, T1, T2, T3, and T4 represent transformers. The wind turbine sets are connected to the grid through a 25kV step-up transformer. The SVG is connected to the grid through a 25kV busbar with a capacity of 20MVA. The wind speed of the double-fed wind turbine is 14m / s. Figure 3The other parameters of the corresponding grid-connected system are shown in Table 1 below:

[0065]

[0066] Table 1 Simulation parameters

[0067] According to Table 1 above, the corresponding parameters of the step-up transformer, the capacity of the SVG, the wind speed of the doubly-fed wind turbine and other parameters can be adjusted and set accordingly through the application layer during actual simulation to achieve simulation adjustment, thereby performing multi-parameter simulation training of the wind turbine generator set.

[0068] The voltage adjustment principle of the wind farm grid connection point of SVG and doubly-fed wind turbines shows that when the reactive power deficit of the wind farm grid-connected system is not greater than the sum of the reactive power capacity that can be provided by SVG and doubly-fed wind turbines, SVG can at least retain 10% of reactive power capacity to ensure the voltage stability of the system when reactive power fluctuations occur in the system. When the reactive power output of the doubly-fed wind turbine participating in voltage regulation reaches the upper limit, SVG can quickly supplement reactive power to the system to ensure that the system voltage is quickly adjusted, thus realizing the coordinated regulation of doubly-fed wind turbines and SVG, making full use of the reactive power capacity of both, reducing the reactive power investment cost of the system, and improving the economic benefits of the operation of the wind farm grid-connected system. Specific embodiment three:

[0070] like Figure 1-4 As shown, the perception layer collects parameters of the wind turbine generator set including current, voltage, frequency, load, wind speed, stability, and fluctuation, and each group of wind turbine generator sets are numbered in digital order. The number and order of phasor measurement devices correspond to the wind turbine generator set one by one. When actually connected to the grid, the controllers or control motherboards of the components or equipment on the surface of each group of wind turbine generator sets are connected to form a data control library, and each data control library is connected to form a neural network structure and controlled by the application layer, so that the parameters of the wind turbine generator set can be adjusted and the data can be read through the controller structure, and the application layer can also perform simulation. The processing layer is based on the perception layer. The parameter information of the wind turbine generator set is used to analyze the signal types in the grid-connected system, which are free oscillation corresponding signals and random corresponding signals. The free oscillation corresponding signals at least include circuit break, line break and instantaneous unit grid connection, and the random corresponding signals at least include random fluctuations in energy output and load switching. The system can collect, store, analyze and process data of multiple groups of wind turbine generator sets through the perception layer and the processing layer, and calculate the oscillation stability of each group of wind turbines and the values ​​of each parameter through the application layer and compare them with the existing stable database structure, so as to realize timely early warning and emergency processing of abnormal conditions of wind turbine generator sets. It has high safety and stability, and is convenient for automatic detection and protection of system faults. Specific embodiment four:

[0072] like Figure 1-4 As shown, the application layer further includes:

[0073] The early warning module stores the data calculation model of the wind turbine generator set, stores the corresponding data of the changes between the parameters through the calculation model, compares the data of the actual wind turbine generator set, and issues a timely early warning when it exceeds a certain threshold;

[0074] The coordination calculation model between the various devices of the wind turbine generator set is as follows. Since the wind turbine generator set captures wind energy and converts it into rotor kinetic energy through the wind turbine, from the perspective of dynamics, according to the further disclosed technical solution, the input power P of the wind turbine v The relationship with other system parameters is as follows:

[0075]

[0076] Where p represents the air density;

[0077] R W Indicates the radius of the wind wheel;

[0078] v represents the flow velocity.

[0079] However, in the actual process of wind energy capture, the wind energy obtained by the rotation of the wind rotor is lost during the capture process. The wind energy utilization coefficient C p To illustrate the conversion rate of wind energy captured by wind turbines:

[0080]

[0081] Where P o Represents the input power of the wind turbine.

[0082] To facilitate the discussion of wind energy utilization coefficient C p The definition of another important parameter is the tip speed ratio λ. The relationship between the tip speed ratio λ and the wind speed, wind rotor speed, and wind rotor diameter is as follows:

[0083]

[0084] In actual wind turbine systems, the required range of wind turbine speed is lower than that of rotor speed. Therefore, a variable speed gearbox is added between the wind turbine and rotor speed to connect the wind turbine and the rotor. The relationship between the rotor speed and the wind turbine speed is as follows:

[0085] burden m =N negative w ④

[0086] Where N represents the speed ratio of the gearbox.

[0087] The wind energy utilization coefficient C p The relationship curve between the pitch angle β and the blade tip speed ratio λ is shown in Table 2:

[0088]

[0089] Table 2C p -λ relationship curve table Substituting equations ②③④ into ①, we can get:

[0090]

[0091] From formula ⑤, we can see that when a certain pitch angle is maintained, there is a maximum tip speed ratio λ opt and the maximum wind energy coefficient C pmax Correspondingly, the wind turbine can capture maximum wind energy.

[0092] Display module, which displays the warning parameters and simulation training parameters in the system, and controls the simulation training parameters by touch;

[0093] The storage module is used to store the grid-connected electric energy of the wind turbine generator set, and is internally provided with filters, voltage regulating equipment, and voltage stabilizing equipment to output the grid electric energy in a stable voltage;

[0094] The simulation training module is used to display and control the electronic structure of multiple wind turbine generator sets, and change the corresponding current, voltage, wind speed and other control parameters through the display module to simulate the actual grid-connected framework structure, and store the simulation data to assist in the comparison and adjustment of the actual parameters of the wind turbine generator set. When using the simulation training, the application layer sets the corresponding wind turbine parameters through the wind farm voltage adjustment and compensation model in the above-mentioned specific embodiment 2, sets the wind speed, blade tip speed ratio and other parameters through the data calculation model of the wind turbine generator set in the early warning module to simulate the power supply of the wind turbine, and adjusts the corresponding parameters according to the changes in the data during the simulation. Adjustment is performed to achieve a stable structure of the wind turbine power supply system. Therefore, the application layer mainly realizes two main functions in the grid-connected system. The first is to analyze and process the collected data of the actual wind turbine power supply unit, identify the oscillation parameters, and issue an early warning through the display module when it exceeds the set threshold range. The second is to simulate the connected wind turbine power supply unit in conjunction with the system framework structure, and conduct simulation experiments through simulated scenarios. While realizing the teaching content, the corresponding parameter changes of the wind turbine power supply unit under different parameters can be detected and stored, providing data reference for the oscillation parameter identification process of the wind turbine power supply unit, and improving safety, stability and accuracy. Specific embodiment five:

[0096] like Figure 1-4As shown, when the entire system framework is actually built, at least a power storage device for wind power generation grid storage is provided inside. At the same time, a network layer is provided in the system framework architecture, and the network layer is internally provided with 4G / 5G communication modules, WiFi communication modules, GPRSS communication modules and other communication methods for connection and data transmission between various levels. The specific communication method can be set in combination with the existing system communication structure in this field.

[0097] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprising a reference structure" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0098] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Anti-islanding low-pressure fan grid-connected control unit system and hardware, characterized by: The system structure consists of a wind turbine generator set, a perception layer, a processing layer and an application layer, and the corresponding hardware structure in the system includes a device framework where the system is located and multiple wind turbine generator sets, wherein: The perception layer is connected to the external wind turbine generator set. It uses multiple sets of phasor measurement devices to accurately record and save the steady-state and dynamic processes of the power signals and electrical quantities of each measuring point of the multiple sets of generator sets in real time, so as to provide a data basis for monitoring and early warning of the wind turbine generator set grid connection. The processing layer receives the monitoring data from the perception layer, centrally aggregates the data obtained by multiple phasor measurement devices through the internal phasor data collector, and electronically synchronizes the connection structure of the wind turbine generator set in real time; The application layer is used for display, early warning, emergency response, power grid storage and simulation training of the entire system. The application layer performs online analysis of the synchronous oscillation mode of the data transmitted by the processing layer, and can display the sub-synchronous oscillation mode parameters and related early warning information on the system interface based on the analysis results of the measured data; The wind turbine generator set provides the wind power grid-connected foundation for the entire system framework. It adopts a wind turbine system structure that combines a doubly-fed wind turbine with a dual PWM converter, and adds a static VAR generator at the wind turbine generator set grid-connected point to perform reactive power compensation for the wind turbine generator set.

2. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 1, characterized in that: The wind turbine generator set is composed of blades, a wind turbine, a gearbox, a double-fed wind turbine, a dual PWM converter, a filter, a static VAR generator and other control systems, wherein: The dual PWM converter is divided into a rotor-side converter and a grid-side converter, and a static VAR generator is connected between the rotor-side converter and the grid-side converter; The static VAR generator receives the reactive current in the system, detects it, generates a PWM pulse signal, and outputs the corresponding total compensation current to manage the reactive power shortage of the power grid.

3. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 1, characterized in that: The perception layer collects parameters of the wind turbine generator set including current, voltage, frequency, load, wind speed, stability, and fluctuation, and each group of wind turbine generator sets is numbered in digital sequence, and the number and sequence of phasor measurement devices correspond one-to-one to the wind turbine generator set.

4. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 1, characterized in that: The application layer further includes: The early warning module stores the data calculation model of the wind turbine generator set, stores the corresponding data of the changes between the parameters through the calculation model, compares the data of the actual wind turbine generator set, and issues a timely early warning when it exceeds a certain threshold; Display module, which displays the warning parameters and simulation training parameters in the system, and controls the simulation training parameters by touch; The storage module is used to store the grid-connected electric energy of the wind turbine generator set, and is internally provided with filters, voltage regulating equipment, and voltage stabilizing equipment to output the grid electric energy in a stable voltage; The simulation training module is used to display and control the electronic structure of multiple wind turbine generator sets, and to change the corresponding current, voltage, wind speed and other control parameters through the display module, to simulate the actual grid-connected framework structure, and to store the simulation data to assist in the comparison and adjustment of the actual parameters of the wind turbine generator sets.

5. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 1, characterized in that: The processing layer analyzes the signal types in the grid-connected system based on the parameter information of the wind turbine generator set in the perception layer, which are free oscillation corresponding signals and random corresponding signals. The free oscillation corresponding signals at least include circuit break, line break and instantaneous unit grid connection, and the random corresponding signals at least include random fluctuations in energy output and load switching.

6. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 1, characterized in that: In the system, the hardware of the entire perception layer, processing layer and application layer are accommodated through an external frame cabinet structure, and are connected to multiple external wind turbine generator sets through grid-connected lines to collect, process, analyze and warn data, forming the hardware structure of the entire wind turbine grid-connected system.

7. The anti-islanding low-pressure wind turbine grid-connected control unit system and hardware according to claim 2, characterized in that: The grid-side converter inside the wind turbine generator set is used to provide stability of the bus voltage and the rotor-side converter. The rotor-side converter controls the power and rotor speed of the stator side of the doubly fed wind turbine by adjusting the current, and is used for coordination with the wind turbine.

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