A method and system for setting the frequency difference fixed value of a synchronous condenser for grid connection

Abstract

The present invention discloses a method and system for setting the frequency difference fixed value of a synchronous condenser for grid connection, which relates to the technical field of automatic control of power systems, and includes: collecting the rotational speed of the synchronous condenser in real time after it enters the coasting state; plotting the coasting curve of the synchronous condenser based on rotational speed-time, and fitting to obtain the rotational speed-time function of the synchronous condenser; calculating the integral of the difference between the rotational speed-time function and the rated rotational speed of the actual power grid to obtain the phase angle difference function between the synchronous condenser and the actual power grid during the grid connection process; based on the phase angle difference function, setting the initial phase angle of the synchronous condenser, making the phase angle difference equal to an integer multiple of 2π, and at the same time, based on the rotational speed-time function, making the rotational speed value equal to the rated rotational speed of the actual power grid, and then performing joint solution, and screening according to multiple time points obtained by the solution to obtain the leading and lagging grid connection closing time points, and further calculating the frequency difference fixed value. The present invention can determine the optimal fixed value for synchronous grid connection, ensure 100% grid connection can be achieved while minimizing the impact on the unit.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control of power systems, and particularly to a method and system for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser. Background Art

[0002] In recent years, synchronous condensers have been widely used in the DC converter stations of power grids. By utilizing their dynamic reactive power support capabilities and transient voltage regulation capabilities, synchronous condensers can effectively suppress commutation failures and improve system stability. Moreover, currently, distributed synchronous condensers are also widely used in new energy power stations. Compared with power electronic compensation devices, distributed synchronous condensers have unique advantages in providing short-circuit capacity and short-term overload capacity to the system. At the same time, they can also provide inertia support and play an important role in improving the voltage stability of new energy power stations.

[0003] Regarding the operation control of synchronous condensers, synchronous grid connection is a key technology in the grid connection process of synchronous condensers. Since synchronous condensers have no prime mover drive, they usually enter the coasting state after being dragged to a certain speed, such as 1.05 times the rated speed, by an SFC (Static Frequency Converter Starter). During the coasting process, the synchronization system captures a suitable synchronization point for grid connection and issues a grid connection command. Therefore, it is necessary to analyze the coasting grid connection process of the synchronous condenser to determine the grid connection success rate of the synchronous condenser under the current fixed value or the fixed value that meets the 100% grid connection condition. Among them, considering that the speed of the synchronous condenser cannot be controlled during the coasting process and decreases at a certain rate, the synchronous condenser mostly uses the differential frequency method for grid connection. Differential frequency grid connection refers to the grid connection operation when the voltages on both sides of the paralleling point are similar, the frequencies are similar, and the phase difference is 0 degrees. The most critical coasting grid connection parameter is the frequency difference fixed value (abbreviated as the frequency difference fixed value). Setting the frequency difference fixed value too large will bring a large grid connection impact to the synchronous condenser, while a smaller frequency difference setting range will result in no synchronous connection point.

[0004] There are still certain problems in the existing methods for setting the fixed values of synchronous grid connection parameters: Since the calculation of the coasting grid connection parameters of synchronous condensers is relatively complex and requires one-by-one analysis of the characteristics of each machine without any coherence and universality, currently, for the connection points that need to be dynamically captured during the coasting grid connection process of synchronous condensers, the analysis and calculation of the frequency difference are mainly based on mathematical models, which are difficult for ordinary personnel to master. Usually, the staff still use empirical values and repeatedly drag the synchronous condenser on-site to verify the rationality of the synchronous grid connection fixed value parameters. On the one hand, this will increase the dragging burden and workload of the unit. And according to the requirements of the regulations and specifications, a dummy synchronization test should be completed before grid connection, at least 3 times, which requires high requirements for the unit and auxiliary systems. On the other hand, it is difficult to ensure the rationality and accuracy of the fixed value setting, and it is difficult to balance and determine the minimum impact current on the unit itself during the synchronization process and the grid connection success rate. In addition, there is currently a lack of targeted devices for analyzing the synchronization process and calculating the fixed values, resulting in potential safety risk points. Summary of the Invention

[0005] To solve the deficiencies of the above-mentioned existing technologies, the present invention provides a method and system for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser. By measuring and obtaining the actual speed parameters during the coasting process of the synchronous condenser, a coasting curve of the synchronous condenser is generated. Through effective analysis and calculation of the coasting curve, the optimal fixed value for synchronous grid connection is determined, ensuring that 100% grid connection can be achieved while minimizing the impact on the unit, effectively reducing the influence of human factors, and ensuring the accuracy of the fixed value.

[0006] In the first aspect, the present invention provides a method for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser.

[0007] A method for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser includes:

[0008] Real-time collect the speed of the synchronous condenser after it enters the coasting state;

[0009] According to the collected speed of the synchronous condenser, draw a coasting curve of the synchronous condenser based on speed-time, and fit to obtain the speed-time function of the synchronous condenser;

[0010] Calculate the integral of the difference between the speed-time function of the synchronous condenser and the rated speed of the actual power grid to obtain the phase angle difference function between the synchronous condenser and the actual power grid during the grid connection process;

[0011] Based on the phase angle difference function, set the initial phase angle of the synchronous condenser, make the phase angle difference equal to an integer multiple of 2π, and at the same time, based on the speed-time function, make the speed value equal to the rated speed of the actual power grid, and perform joint solution accordingly. Then, screen according to the multiple time points obtained from the solution to obtain the closing time points of the in-phase and out-of-phase grid connection points;

[0012] Calculate the frequency difference fixed value according to the closing time of the in-phase and out-of-phase grid connection points.

[0013] In the second aspect, the present invention provides a system for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser.

[0014] A system for setting the frequency difference fixed value for the synchronous grid connection of a synchronous condenser includes:

[0015] A sampling module for real-time collecting the speed of the synchronous condenser after it enters the coasting state;

[0016] A data analysis module, which is used to draw the coasting curve of the synchronous condenser based on the rotational speed-time according to the collected rotational speed of the synchronous condenser, and fit to obtain the rotational speed-time function of the synchronous condenser; calculate the integral of the difference between the rotational speed-time function of the synchronous condenser and the rated rotational speed of the actual power grid to obtain the phase angle difference function between the synchronous condenser and the actual power grid during the grid connection process; based on the phase angle difference function, set the initial phase angle of the synchronous condenser, make the phase angle difference equal to an integer multiple of 2π, and at the same time, based on the rotational speed-time function, make the rotational speed value equal to the rated rotational speed of the actual power grid, so as to perform joint solution, and screen according to multiple time points obtained by the solution to obtain the leading and lagging grid connection closing time points, and then calculate the frequency difference setting value.

[0017] A further technical solution further includes:

[0018] An operation display module, which is used to input and display the relevant parameters of the synchronous condenser's synchronous grid connection and the calculated frequency difference setting value; wherein, the relevant parameters include unit information, grid connection voltage, transformer ratio, closing lead time, and synchronous device information.

[0019] In a third aspect, the present invention further provides an electronic device, including: a memory for storing executable instructions; a processor, when executing the executable instructions stored in the memory, implementing the above-mentioned method for setting the frequency difference setting value of the synchronous condenser's synchronous grid connection.

[0020] In a fourth aspect, the present invention further provides a computer-readable storage medium, storing executable instructions, which are used to cause a processor to implement the above-mentioned method for setting the frequency difference setting value of the synchronous condenser's synchronous grid connection when executing the executable instructions.

[0021] In a fifth aspect, the present invention further provides a computer program product, which includes executable instructions stored in a computer-readable storage medium; wherein, when a processor of an electronic device reads the executable instructions from the computer-readable storage medium and executes the executable instructions, the above-mentioned method for setting the frequency difference setting value of the synchronous condenser's synchronous grid connection is implemented.

[0022] The above one or more technical solutions have the following beneficial effects:

[0023] 1. The present invention provides a method and system for setting the frequency difference setting value of the synchronous condenser's synchronous grid connection. By measuring and obtaining the actual rotational speed data of the synchronous condenser during the coasting process through any method such as voltage, small current signal, digital signal, etc., the coasting curve of the synchronous condenser can be more simply and conveniently fitted; through effective analysis and calculation of the coasting curve, the optimal frequency difference setting value for synchronous grid connection is determined, ensuring that 100% grid connection can be achieved while minimizing the impact on the unit, effectively reducing the influence of human factors, ensuring the accuracy of the frequency difference setting value, reducing the number of times of frequent dragging and false synchronization of the unit, improving the progress of on-site work efficiency, and reducing the workload of personnel.

[0024] 2. In the method for setting the frequency difference fixed value for the synchronous grid connection of the synchronous condenser proposed by the present invention, for the obtained coasting-down curve, the phase angle difference function during the grid connection process is obtained by subtracting the actual grid rated speed and then integrating, and then combined with the rotation characteristics of the synchronous condenser, the characteristics of the phase angle difference function are analyzed, and it is clear that the final frequency difference setting is actually to find the maximum value of the minimum point of the grid connection frequency difference. Based on this, the final set frequency difference and its range are solved according to the speed-time function and the phase angle difference function describing the coasting-down curve. There must be a grid connection point within this frequency difference range that can meet the grid connection closing conditions, and the impact on the unit during grid connection closing at this grid connection point is the smallest. For the above method proposed by the present invention, the entire calculation process is simple, the operation cost is low, and the efficiency is high. It can conveniently, quickly, and accurately complete the setting of the frequency difference fixed value for the synchronous grid connection of the synchronous condenser, and then realize the synchronous grid connection of the synchronous condenser.

[0025] 3. The present invention also proposes a system for setting the frequency difference fixed value for the synchronous grid connection of the synchronous condenser. This system can be realized through specific devices. It can directly and automatically calculate the accurate frequency difference fixed value through the input relevant parameters of the synchronous grid connection of the synchronous condenser and output it, which is convenient for on-site use, improves the on-site work efficiency progress, reduces the personnel work burden, and has higher wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The attached drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0027] Figure 1 It is the overall flowchart of the method for setting the frequency difference fixed value for the synchronous grid connection of the synchronous condenser according to the embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the coasting-down curve of the synchronous condenser in the embodiment of the present invention;

[0029] Figure 3 It is a schematic curve diagram of the grid connection phase angle difference function of the synchronous condenser in the embodiment of the present invention;

[0030] Figure 4 It is a schematic diagram of the actual grid connection phase angle difference of the synchronous condenser in the embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the system for setting the frequency difference fixed value for the synchronous grid connection of the synchronous condenser according to the embodiment of the present invention.

[0032] Among them, 1. Sampling module; 2. Data analysis module; 3. Operation display module; 4. Housing; 5. Voltage signal interface; 6. 4-20mA small current signal interface; 7. Communication interface; 8. Operation panel; 9. Display screen; 10. Power supply interface; 11. Grounding interface. Specific Embodiments

[0033] It should be noted that the following detailed description is exemplary only for describing specific embodiments, aiming to provide further explanation of the present invention and not intended to limit the exemplary embodiments according to the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] Embodiment 1

[0035] This embodiment provides a method for setting the frequency difference setting value for the synchronous grid connection of a synchronous condenser, as Figure 1 shown, specifically including the following steps:

[0036] Step S1: Real-time collect the speed of the synchronous condenser after it enters the coasting state. Specifically, considering different actual situations, various different methods can be used to obtain the speed of the synchronous condenser, including:

[0037] (1) Collect the terminal voltage signal of the synchronous condenser, analyze and process it according to the voltage frequency or voltage signal period of the terminal voltage signal, and calculate the unit speed. For example, according to the voltage frequency (unit Hz) of the terminal voltage, use the formula to calculate the unit speed (unit rpm ); or, according to the voltage signal period (unit s) of the terminal voltage, use the formula to calculate the unit speed (unit rpm ).

[0038] (2) Obtain the 4 - 20mA small current signal I converted from the speed collected by the signal sensor. According to the small current signal I collected by the signal sensor, use the formula to calculate the unit speed. Among them, 3500 rpm is the speed corresponding to the upper limit of the signal sensor, that is, the speed value corresponding to 20mA; 0 rpm is the speed corresponding to the lower limit of the signal sensor, that is, the speed value corresponding to 4mA.

[0039] (3) Directly collect the speed digital signal through the network cable to obtain the unit speed.

[0040] The above-mentioned various methods for obtaining the speed of the synchronous condenser can ensure the effective acquisition of the speed of the synchronous condenser and the accuracy of the obtained speed. For example, multiple methods can be used for comparison and verification to ensure the effective and accurate acquisition of the final speed.

[0041] Step S2: Based on the collected synchronous condenser speed, plot the coasting curve of the synchronous condenser based on speed-time, and obtain the speed-time function of the synchronous condenser by fitting.

[0042] Through the synchronous condenser speed obtained by the above acquisition, the function of speed with respect to time is obtained , and a typical coasting curve of the synchronous condenser is as Figure 2 shown, where near the rated speed of the power system 3000 rpm (the rated frequency of the power system is 50 Hz, corresponding to a speed of 3000 rpm ) can be approximated as a straight line, and the coasting slope k is obtained through curve fitting. Furthermore, the speed-time function can be obtained. The expression of this linear function of speed with respect to time can be expressed as:

[0043] (1)

[0044] In the above formula, k represents the coasting slope, t represents time, represents the initial value of speed.

[0045] Step S3: Calculate the integral of the difference between the speed-time function of the synchronous condenser and the actual grid rated speed to obtain the phase angle difference function between the synchronous condenser and the actual grid during the grid connection process.

[0046] Specifically, calculate the difference between the speed-time function of the synchronous condenser and the rated speed of the actual grid (i.e., the power system), where the rated speed of the power system is 3000 rpm , and integrate this difference to obtain the phase angle difference between the synchronous condenser and the actual grid during the grid connection process. This phase angle difference function can be expressed as:

[0047] (2)

[0048] (3)

[0049] In the above formula, represents the initial phase angle, represents the phase angle difference.

[0050] Through the above calculation, a quadratic function of the phase angle difference with respect to time is obtained. A typical phase angle difference is as Figure 3 shown. Since the synchronous condenser is a rotating device, the phase angle returns to zero every revolution (i.e., 2π), and thus the phase angle difference returns to zero. Therefore, the actual phase angle difference during the grid connection of the synchronous condenser is as Figure 4 shown.

[0051] Step S4: Based on the phase angle difference function, set the initial phase angle of the synchronous condenser, making the phase angle difference equal to an integer multiple of 2π. At the same time, based on the rotational speed - time function, set the rotational speed value equal to the rated rotational speed of the actual power grid, and perform joint solution accordingly. Then, screen according to the multiple time points obtained from the solution to obtain the leading and lagging grid connection time points of the connection point.

[0052] Combined with Figure 4 It can be seen that Figure 4 each point with a phase angle difference of 0 in is the target connection point, and the target connection points appear periodically with unequal intervals; considering that rotational speed = frequency * 60 and rotational speed corresponds to frequency, when the rotational speed is closest to the rated rotational speed, the frequency is closest to the rated frequency, and at this time, the frequency difference between the synchronous condenser and the power system is the smallest, that is, the frequency difference of the connection point closest to the rated rotational speed is the smallest. In this embodiment, according to the rotational speed - time function of the synchronous condenser, set the rotational speed value equal to the rated rotational speed of the actual power grid, and solve to obtain the midpoint time

[0053] At this midpoint time, the grid connection frequency difference between the synchronous condenser and the power system is the smallest. Furthermore, considering that the initial phase angle of the synchronous condenser is a random value at the start time of grid connection, this value is uncertain. Since the initial time of the synchronous condenser's coasting to grid connection is not fixed in different situations, the initial phase angle is different, and this uncertainty leads to different frequency differences at the grid connection time. Therefore, the ultimate goal is actually to find the maximum value of the point with the smallest grid connection frequency difference, that is, the required frequency difference is the maximum frequency difference closest to the rated rotational speed obtained when the initial phase angle takes different values. In this embodiment, set the initial phase angle

[0054] such that the phase angle difference is close to an integer multiple of 2π (at this time the phase angle difference is close to 0), and perform the solution accordingly. For the several time points obtained from the solution, take the two time points before and after the closest to the midpoint time as the leading and lagging grid connection time points of the connection point. At this time, the target connection points corresponding to these two time points are the farthest from the rated rotational speed, and the generated frequency difference is the largest. Within the frequency difference range corresponding to these two time points, there must be a connection point that can meet the grid connection and closing conditions, and grid connection and closing at this connection point cause the least impact on the unit.

[0055] (4)

[0056] (5)

[0057] In the above formula, is a positive integer.

[0058] After solution, calculate to obtain the midpoint time and the leading and lagging grid connection time points of the connection point 、 .

[0059] Step S5: Calculate the frequency difference setting value based on the closing times of the in-phase connection points with lead and lag.

[0060] Specifically, substitute the obtained time points 、 into the above formula (1) to solve for the corresponding rotational speeds 、 , which respectively correspond to the rotational speeds of the in-phase connection points with lead and lag; further, according to rotational speed = frequency * 60 and the rated frequency of the power system being 50 Hz, the frequency difference setting value can be calculated as 、 , and then determine the frequency difference range . Within this frequency difference range, there must be an in-phase connection point that can meet the grid connection closing conditions, and grid connection and closing at this in-phase connection point cause the least impact on the unit.

[0061] Embodiment 2

[0062] This embodiment provides a setting system for the frequency difference setting value of a synchronous condenser for grid connection. This system can be implemented through specific devices, such as Figure 5 shown, and includes a sampling module 1, a data analysis module 2, and an operation display module 3, specifically:

[0063] The sampling module is used to collect the rotational speed of the synchronous condenser in real time after it enters the coasting state.

[0064] The data analysis module is used to draw the coasting curve of the synchronous condenser based on the rotational speed - time according to the collected rotational speed of the synchronous condenser, and fit to obtain the rotational speed - time function of the synchronous condenser; calculate the integral of the difference between the rotational speed - time function of the synchronous condenser and the rated rotational speed of the actual power grid to obtain the phase angle difference function between the synchronous condenser and the actual power grid during the grid connection process; based on the phase angle difference function, set the initial phase angle of the synchronous condenser to make the phase angle difference equal to an integer multiple of 2π, and at the same time, based on the rotational speed - time function, make the rotational speed value equal to the rated rotational speed of the actual power grid, and perform joint solution accordingly, and screen according to the obtained multiple time points to obtain the closing time points of the in-phase connection points with lead and lag, and then calculate the frequency difference setting value.

[0065] The operation display module is used to input and display the parameters related to the synchronous condenser for grid connection and the calculated frequency difference setting value; among them, the said related parameters include unit information, grid connection voltage, transformer ratio, closing lead time, synchronous device information, etc.

[0066] In this embodiment, the phasor measurement unit synchronization grid-connected frequency difference setting value system is implemented through specific devices, which includes a housing 4. A sampling module 1 for performing the sampling link is provided on the housing 4. The module includes a voltage signal interface 5, a 4-20 mA small current signal interface 6, and a communication interface 7, which can respectively collect the terminal voltage signal, small current signal, and rotational speed digital signal of the synchronous condenser; a data analysis module 2 is provided inside the housing 4 for performing data analysis and calculation, that is, for performing the phasor measurement unit synchronization grid-connected frequency difference setting value method proposed in the above-mentioned Embodiment 1; an operation display module 3 is provided on the outer surface of the housing 4. The operation display module 3 includes an operation panel 8 and a display screen 9. A variety of operation buttons are provided on the operation panel 8 for inputting relevant parameters of the phasor measurement unit synchronization grid connection, and the display screen 9 is used to display the input relevant parameters of the phasor measurement unit synchronization grid connection and the calculated frequency difference setting value. In addition, a power interface 10, a grounding interface 11, etc. are also provided on the device for subsequent safe and convenient use.

[0067] Embodiment 3

[0068] This embodiment provides an electronic device, including: a memory for storing executable instructions; a processor for implementing the above method provided in this embodiment when executing the executable instructions stored in the memory.

[0069] Embodiment 4

[0070] This embodiment also provides a computer-readable storage medium storing executable instructions, which, when executed by a processor, will cause the processor to execute the above method provided in this embodiment.

[0071] Embodiment 5

[0072] This embodiment provides a computer program product, which includes executable instructions, and the executable instructions are computer instructions; the executable instructions are stored in a computer-readable storage medium. When the processor of an electronic device reads the executable instructions from the computer-readable storage medium and the processor executes the executable instructions, the electronic device is caused to execute the above method provided in this embodiment.

[0073] The steps involved in Embodiments 2 to 5 above correspond to those in Method Embodiment 1. For specific implementation manners, reference may be made to the relevant description part of Embodiment 1. The term "computer-readable storage medium" should be understood to include a single medium or multiple media containing one or more instruction sets; it should also be understood to include any medium that can store, encode, or carry an instruction set for execution by a processor and cause the processor to execute any method in the present invention.

[0074] Those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computer device. Optionally, they can be implemented by program codes executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0075] The above are only the preferred embodiments of the present invention. Although the specific implementation manners of the present invention have been described in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications or deformations that can be made without creative efforts on the basis of the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for setting the frequency difference of a phase regulator synchronously connected to the grid, characterized in that: include: Real-time acquisition of the rotation speed of the condenser after it enters the idling state; According to the collected condenser speed, the condenser idling curve based on speed-time is drawn, and the speed-time function of the condenser is obtained by fitting; Calculate the integral of the difference between the speed-time function of the phase regulator and the actual rated speed of the power grid, and obtain the phase angle difference function between the phase regulator and the actual power grid during the grid connection process; Based on the phase angle difference function, the initial phase angle of the phase regulator is set to an integer multiple of 2π. At the same time, based on the speed-time function, the speed value is set to be equal to the rated speed of the actual power grid. This is used for joint solution, and multiple time points obtained are screened to obtain the leading and lagging grid connection point closing time points. The frequency difference setting value is calculated based on the leading and lagging grid connection point closing times; The frequency difference setting of synchronous grid-connected phase regulator refers to finding and solving the maximum value of the minimum grid-connected frequency difference, including: According to the speed-time function of the phase regulator, let the speed value be equal to the rated speed of the actual power grid, and solve for the midpoint time , at the midpoint The frequency difference between the time-controlled servo motor and the power grid is minimal; Based on the phase angle difference function, the initial phase angle of the phase condenser is set, and the phase angle difference is equal to an integer multiple of 2π, and several time points are obtained by solving; The two time points closest to the midpoint are the leading and lagging grid connection closing time points. and , the target grid-connected points corresponding to these two time points are farthest from the rated speed, and the resulting frequency difference is the largest.

2. A method for setting the frequency difference of a phase regulator connected to the grid synchronously as claimed in claim 1, characterized in that: Collect and obtain the speed of the phase regulator, including: Collect the terminal voltage signal of the phase regulator, and calculate the unit speed, that is, the speed of the phase regulator, according to the voltage frequency or voltage signal period of the terminal voltage signal; or, The small current signal I collected by the signal sensor is obtained, and the unit speed, that is, the speed of the phase regulator, is calculated based on the small current signal I and the speed corresponding to the upper and lower limits of the signal sensor; or, the speed digital signal is collected to obtain the unit speed, that is, the speed of the phase regulator.

3. A method for setting the frequency difference of a phase regulator connected to the grid synchronously as claimed in claim 1, characterized in that: The speed-time function is a linear function of the speed with respect to time, and the expression of the function is: ; The phase angle difference function between the phase regulator and the actual power grid during the grid connection process is: ； In the above formula, k represents the idling slope, t Indicates time, Indicates the initial value of the speed. represents the initial phase angle, Indicates the phase angle difference.

4. A method for setting the frequency difference of a phase regulator synchronously connected to the grid as claimed in claim 1, characterized in that: According to the obtained leading and lagging grid connection point closing time points and , substitute into the speed-time function and solve for the corresponding speed , , corresponding to the leading and lagging grid connection point speeds respectively; According to speed = frequency * 60 and the rated frequency of the power system, the frequency difference setting value is calculated and the frequency difference range is determined.

5. A frequency difference setting system for synchronous grid-connected phase regulator, characterized in that: include: The sampling module is used to collect the rotation speed of the phase regulator in real time after it enters the idling state; The data analysis module is used to draw the phase condenser idling curve based on speed-time according to the collected phase condenser speed, and fit the speed-time function of the phase condenser; calculate the integral of the difference between the speed-time function of the phase condenser and the rated speed of the actual power grid, and obtain the phase angle difference function between the phase condenser and the actual power grid during the grid connection process; based on the phase angle difference function, set the initial phase angle of the phase condenser, make the phase angle difference equal to an integer multiple of 2π, and at the same time, based on the speed-time function, make the speed value equal to the rated speed of the actual power grid, so as to perform a joint solution, and screen the multiple time points obtained by the solution to obtain the leading and lagging grid connection point closing time points, and then calculate the frequency difference setting value; The frequency difference setting of synchronous grid-connected phase regulator refers to finding and solving the maximum value of the minimum grid-connected frequency difference, including: According to the speed-time function of the phase regulator, let the speed value be equal to the rated speed of the actual power grid, and solve for the midpoint time , at the midpoint The frequency difference between the time-controlled servo motor and the power grid is minimal; Based on the phase angle difference function, the initial phase angle of the phase condenser is set, and the phase angle difference is equal to an integer multiple of 2π, and several time points are obtained by solving; The two time points closest to the midpoint are the leading and lagging grid connection closing time points. and , the target grid-connected points corresponding to these two time points are farthest from the rated speed, and the resulting frequency difference is the largest.

6. A phase regulator synchronous grid-connected frequency difference setting system as claimed in claim 5, characterized in that: Also includes: Operation and display module, used to input and display phase regulator synchronization grid-connected related parameters and calculate the frequency difference setting value; The relevant parameters include unit information, grid-connected voltage, transformer ratio, closing lead time, and synchronization device information.

7. An electronic device, characterized in that: include: A memory for storing executable instructions; The processor is used to implement the method for setting the frequency difference constant of the synchronous grid-connected phase regulator according to any one of claims 1 to 4 when executing the executable instructions stored in the memory.

8. A computer-readable storage medium, characterized in that: Executable instructions are stored, which are used to cause the processor to execute the executable instructions to implement a method for setting a frequency difference constant value of a phase-converter synchronously connected to the grid as described in any one of claims 1-4.

9. A computer program product, characterized in that The computer program product includes executable instructions stored in a computer-readable storage medium; When the processor of the electronic device reads the executable instructions from the computer-readable storage medium and executes the executable instructions, the method for setting the frequency difference constant of the synchronous grid-connected phase regulator described in any one of claims 1 to 4 is implemented.

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