Control method and device based on static power angle and voltage stability margin of photovoltaic power station

Abstract

The invention provides a control method and device based on a static power angle and a voltage stability margin of a photovoltaic power station. The method comprises the following steps: acquiring a pre-established conversion relation between a lifting index of the static power angle and the voltage stability margin of the photovoltaic power station and a lifting parameter of the static power angle and the voltage stability margin of the photovoltaic power station; establishing a time sequence of each lifting parameter; determining an influence factor of each lifting parameter at the next moment based on each lifting parameter; based on the time sequence and the influence factor, determining a lifting parameter prediction value of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment; performing normalization processing on the lifting parameter prediction values of the static power angle and the voltage stability margin of the photovoltaic power station to obtain corresponding normalized values; based on the normalized value, determining a promotion index prediction value of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment; and based on the promotion index prediction value, controlling a power grid system of the photovoltaic power station, accurately predicting the static power angle and voltage stability margin change of the photovoltaic power station, and realizing power grid stability.

Description

Technical Field

[0001] The present invention relates to the technical field of power quality optimization of photovoltaic power stations, and in particular to a control method and device based on static power angle and voltage stability margin of photovoltaic power stations. Background Art

[0002] In recent years, with the global emphasis on and promotion of renewable energy, new energy power generation sites represented by photovoltaics have increased rapidly and are connected to traditional power systems at a high rate. This trend has gradually led to the modern power system showing a "double high" feature - a high proportion of renewable energy and a high degree of power electronics. This transformation has brought many new challenges, especially in terms of power system stability and power quality.

[0003] As an important part of new energy, photovoltaic power stations show characteristics different from traditional power generation methods during operation. Their power generation capacity is directly affected by sunshine conditions and is intermittent and volatile. In addition, although the photovoltaic inverters used in large quantities in photovoltaic power stations can convert direct current into alternating current and feed it into the power grid, they provide limited frequency and voltage support. In the absence of an energy storage system, these characteristics may lead to voltage instability and power angle instability in the power system when disturbed, thus affecting the safe and stable operation of the entire power grid.

[0004] In order to deal with the above problems, ensure that photovoltaic power plants can provide stable power quality under various operating conditions, and provide effective active support to the power grid when necessary, it is necessary to improve the static power angle and voltage stability margin of photovoltaic power plants. However, there is currently a lack of effective technical solutions for how to accurately predict the changes in the static power angle and voltage stability margin of photovoltaic power plants, and how to effectively adjust the behavior of photovoltaic power plants or power grids based on the prediction results to achieve optimal stability and power quality. Summary of the invention

[0005] The present invention provides a control method and device based on the static power angle and voltage stability margin of a photovoltaic power station, which is used to solve the technical problem in the prior art that the static power angle and voltage stability margin changes of the photovoltaic power station cannot be accurately predicted, and thus the grid stability cannot be effectively achieved.

[0006] In one aspect, the present invention provides a control method based on a static power angle and a voltage stability margin of a photovoltaic power station, comprising:

[0007] Obtaining a conversion relationship between a pre-established improvement index of the static power angle and voltage stability margin of a photovoltaic power station and an improvement parameter of the static power angle and voltage stability margin of the photovoltaic power station; wherein the improvement parameters include the total input power and total output power of the grid-connected inverter in the photovoltaic power station, the total input power and total output power of the grid-following inverter, the inverter static power angle, and the voltage of the MW-class synchronous machine in the grid-connected mode;

[0008] Establishing a time series of each of the boosting parameters;

[0009] Based on the boost parameters, determining the impact factor of each boost parameter at the next moment;

[0010] Based on the time series and the influencing factors, determining the predicted values ​​of the improved parameters of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment;

[0011] Normalizing the predicted values ​​of the static power angle and voltage stability margin of the photovoltaic power station to obtain corresponding normalized values;

[0012] Based on the normalized value, determining a predicted value of an improvement index of a static power angle and a voltage stability margin of the photovoltaic power station at a next moment;

[0013] Based on the predicted value of the boost index, a power grid system of the photovoltaic power station is controlled.

[0014] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the conversion relationship is shown in the following formula (1):

[0015]

[0016] The time series is shown in the following formula (2):

[0017]

[0018] Among them, CI SPA-VSM is the static power angle and voltage stability margin improvement index of the photovoltaic power station, T1, T2, ..., T z ,...,T m is the time at a fixed time interval, where m is a natural number, z is the zth time, and z is a natural number, z∈{1,2,L,m}; N is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total input power of the grid-connected inverter in the photovoltaic power station, T z At the moment, the output power of the i-th grid-connected inverter in the photovoltaic power station is is the total output power of the grid-connected inverters in the photovoltaic power station; M is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, It is the total output power of the grid-connected inverter in the photovoltaic power station; T zThe output power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total output power of the grid-type inverter in the photovoltaic power station; the allowable power factor of the photovoltaic inverter is (-cosφ, cosφ), T z The static power angle of the photovoltaic inverter at this moment.

[0019] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the influencing factor can be expressed as the following formula (3):

[0020]

[0021] in, For the T z The influence factor of the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the moment on the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the next moment; P MDC-i,min The input power of the grid-connected inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P MAC-i,max The grid-type inverter output power is T1, T2, ..., T z ,...,T m The maximum value of the measured value at these m fixed time intervals; P LDC-i,min The input power of the grid-following inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P LAC-i,max The output power of the grid-following inverter is T1, T2, ..., T z ,...,T m The maximum value of the measured values ​​at these m fixed time intervals.

[0022] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the parameter prediction value is improved as shown in the following formula (4):

[0023]

[0024] in, T m+1 The predicted value of the total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total input power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the static power angle of the inverter at the moment; T m+1 The predicted value of the voltage in the grid-connected mode of the MW-class synchronous machine at the moment.

[0025] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the normalized value is shown in the following formula (5):

[0026]

[0027] in, T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the static power angle prediction value of the inverter at the moment; T m+1 The normalized value of the voltage prediction value in the MW-class synchronous machine grid-connected mode at time t; P MAC-i,min For T1, T2, ..., T z ,...,T m The minimum value of the measured output power of the grid-connected inverter in the m fixed time intervals; P LAC-i,min For T1, T2, ..., T z ,...,T m The minimum output power of the grid-connected inverter during these m fixed time intervals; P MDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; P LDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; is the static power angle of the inverter at T1, T2, ..., T z,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals; U SG,max , U SG,min The voltage of MW-class synchronous machine in grid-connected mode is T1, T2, ..., T z ,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals.

[0028] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the predicted value of the improvement index is shown in the following formula (6):

[0029]

[0030] in, To improve the predicted value of the index.

[0031] According to a control method based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the power grid system of the photovoltaic power station is controlled based on the predicted value of the boost index, including:

[0032] Comparing the predicted value of the improvement index with a preset index threshold;

[0033] When the predicted value of the boost index is less than the preset index threshold, increasing the output power of the MW-class synchronous machine in the power grid to compensate for the output of the photovoltaic power station;

[0034] When the predicted value of the boost index is greater than or equal to the preset index threshold, the output power of the MW-class synchronous machine in the power grid is reduced to compensate for the output of the photovoltaic power station.

[0035] According to a control method based on static power angle and voltage stability margin of a photovoltaic power station provided by the present invention, the preset index threshold is 0.637.

[0036] On the other hand, the present invention also provides a control device based on the static power angle and voltage stability margin of a photovoltaic power station, comprising:

[0037] An acquisition module is provided to acquire a conversion relationship between a pre-established improvement index of a photovoltaic power station static power angle and a voltage stability margin and an improvement parameter of a photovoltaic power station static power angle and a voltage stability margin; wherein the improvement parameter includes a total input power and a total output power of a grid-connected inverter in the photovoltaic power station, a total input power and a total output power of a grid-following inverter, an inverter static power angle, and a voltage of a MW-class synchronous machine in a grid-connected mode;

[0038] A time series module, for establishing a time series of each of the boosted parameters;

[0039] An impact factor module, based on each of the boost parameters, determines the impact factor of each boost parameter at the next moment;

[0040] A first prediction module determines, based on the time series and the influencing factors, prediction values ​​of the improvement parameters of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment;

[0041] The normalization module normalizes the predicted values ​​of the static power angle and voltage stability margin of the photovoltaic power station to obtain the corresponding normalized values;

[0042] A second prediction module determines, based on the normalized value, a prediction value of an improvement index of a static power angle and a voltage stability margin of the photovoltaic power station at a next moment;

[0043] A control module controls a power grid system of the photovoltaic power station based on the predicted value of the boost index.

[0044] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the control method based on the static power angle and voltage stability margin of a photovoltaic power station as described above is implemented.

[0045] The control method and device based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention obtain the conversion relationship between the pre-established improvement index of the static power angle and voltage stability margin of the photovoltaic power station and the improvement parameter of the static power angle and voltage stability margin of the photovoltaic power station; establish a time series of each improvement parameter; based on each improvement parameter, determine the influencing factor of each improvement parameter at the next moment; based on the time series and the influencing factor, determine the improvement parameter prediction value of the static power angle and voltage stability margin of the photovoltaic power station at the next moment; normalize the improvement parameter prediction value of the static power angle and voltage stability margin of the photovoltaic power station to obtain the corresponding normalized value; based on the normalized value, determine the improvement index prediction value of the static power angle and voltage stability margin of the photovoltaic power station at the next moment; based on the improvement index prediction value, control the power grid system of the photovoltaic power station, realize accurate prediction of the static power angle and voltage stability margin changes of the photovoltaic power station, improve and optimize the static power angle and voltage stability margin of the photovoltaic power station, thereby providing a certain degree of active support capability for the power grid and improving the stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 It is a flow chart of a control method based on static power angle and voltage stability margin of a photovoltaic power station provided by an embodiment of the present invention;

[0048] Figure 2 It is a structural schematic diagram of a control device based on static power angle and voltage stability margin of a photovoltaic power station provided by an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0051] Figure 1 It is a flow chart of a method for controlling transient power angle of a station with photovoltaic standby participating in multiple grid-connected modes provided by an embodiment of the present invention.

[0052] See also Figure 1 The method for controlling transient power angle of a station with multi-grid-connected mode photovoltaic backup participating may include the following steps.

[0053] 101. Obtain the conversion relationship between the pre-established improvement index of the static power angle and voltage stability margin of the photovoltaic power station and the improvement parameters of the static power angle and voltage stability margin of the photovoltaic power station. The improvement parameters include the total input power and total output power of the grid-connected inverter in the photovoltaic power station, the total input power and total output power of the grid-following inverter, the inverter static power angle, and the voltage of the MW-class synchronous machine in the grid-connected mode.

[0054] 102. Establish a time series for each boost parameter.

[0055] The conversion relationship is shown in the following formula (1):

[0056]

[0057] The time series is shown in the following formula (2):

[0058]

[0059] Among them, CI SPA-VSM is the static power angle and voltage stability margin improvement index of the photovoltaic power station, T1, T2, ..., T z ,...,T mis a fixed time interval (a total of m), where m is a natural number, z is the zth moment, and z is a natural number, z∈{1,2,L,m}; N is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total input power of the grid-connected inverter in the photovoltaic power station, T z At the moment, the output power of the i-th grid-connected inverter in the photovoltaic power station is is the total output power of the grid-connected inverters in the photovoltaic power station; M is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, It is the total output power of the grid-connected inverter in the photovoltaic power station; T z The output power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total output power of the grid-type inverter in the photovoltaic power station; the allowable power factor of the photovoltaic inverter is (-cosφ, cosφ), T z The static power angle of the photovoltaic inverter at this moment.

[0060] 103. Based on each boosting parameter, determine an impact factor of each boosting parameter at a next moment.

[0061] The impact factor can be expressed as follows:

[0062]

[0063] in, For the T z The influence factor of the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the moment on the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the next moment; P MDC-i,min The input power of the grid-connected inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P MAC-i,max The grid-type inverter output power is T1, T2, ..., T z ,...,T m The maximum value of the measured value at these m fixed time intervals; P LDC-i,min The input power of the grid-following inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P LAC-i,maxThe output power of the grid-following inverter is T1, T2, ..., T z ,...,T m The maximum value of the measured values ​​at these m fixed time intervals.

[0064] 104. Based on the time series and influencing factors, determine the predicted values ​​of the improved parameters of the static power angle and voltage stability margin of the photovoltaic power station at the next moment.

[0065] The predicted value of the improved parameter is shown in the following formula (4):

[0066]

[0067] in, T m+1 The predicted value of the total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total input power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the static power angle of the inverter at the moment; T m+1 The predicted value of the voltage of the MW-class synchronous machine in the grid-connected mode at the time. The next time refers to the next time of the current time. For example, m represents the current time, and m+1 represents the next time.

[0068] 105. Normalize the predicted values ​​of the enhancement parameters of the static power angle and the voltage stability margin of the photovoltaic power station to obtain corresponding normalized values.

[0069] The normalized value is shown in the following formula (5):

[0070]

[0071] in, T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the static power angle prediction value of the inverter at the moment; T m+1 The normalized value of the voltage prediction value in the MW-class synchronous machine grid-connected mode at time t; P MAC-i,min For T1, T2, ..., T z ,...,T m The minimum value of the measured output power of the grid-connected inverter in the m fixed time intervals; P LAC-i,min For T1, T2, ..., T z ,...,T m The minimum output power of the grid-connected inverter during these m fixed time intervals; P MDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; P LDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; is the static power angle of the inverter at T1, T2, ..., T z ,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals; U SG,max , U SG,min The voltage of MW-class synchronous machine in grid-connected mode is T1, T2, ..., T z ,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals.

[0072] 106. Based on the normalized value, determine the predicted value of the improvement index of the static power angle and voltage stability margin of the photovoltaic power station at the next moment.

[0073] The predicted value of the lifting index is shown in the following formula (6):

[0074]

[0075] in, To improve the predicted value of the index.

[0076] 107. Based on the predicted value of the boost index, control the grid system of the photovoltaic power station.

[0077] In this embodiment, a conversion relationship between a pre-established improvement index of a photovoltaic power station static power angle and a voltage stability margin and an improvement parameter of the photovoltaic power station static power angle and a voltage stability margin is obtained; a time series of each improvement parameter is established; based on each improvement parameter, an influencing factor of each improvement parameter at the next moment is determined; based on the time series and the influencing factor, a predicted value of the improvement parameter of the photovoltaic power station static power angle and the voltage stability margin at the next moment is determined; the predicted value of the improvement parameter of the photovoltaic power station static power angle and the voltage stability margin is normalized to obtain a corresponding normalized value; based on the normalized value, a predicted value of the improvement index of the photovoltaic power station static power angle and the voltage stability margin at the next moment is determined; based on the predicted value of the improvement index, a power grid system of the photovoltaic power station is controlled, and accurate prediction of changes in the static power angle and the voltage stability margin of the photovoltaic power station is achieved, and the static power angle and the voltage stability margin of the photovoltaic power station are improved and optimized, thereby providing a certain degree of active support capability for the power grid and improving the stability of the power grid.

[0078] In one embodiment of the present specification, the controlling of the power grid system of the photovoltaic power station based on the predicted value of the boost index includes:

[0079] Comparing the predicted value of the improvement index with a preset index threshold;

[0080] When the predicted value of the boost index is less than the preset index threshold, increasing the output power of the MW-class synchronous machine in the power grid to compensate for the output of the photovoltaic power station;

[0081] When the predicted value of the boost index is greater than or equal to the preset index threshold, the output power of the MW-class synchronous machine in the power grid is reduced to compensate for the output of the photovoltaic power station.

[0082] In this embodiment, when the predicted value of the boost index is less than the preset index threshold, it is considered that the static power angle and voltage stability margin boost capabilities of the photovoltaic power station at the next moment are relatively poor, so that it cannot provide stable high-quality electric energy to meet the active support needs of the power grid. The output power of the photovoltaic power station can be increased by increasing the output power of the MW-level synchronous machine in the power grid to meet the active support needs of the power grid, ensuring that the power grid can use sufficient energy conversion for optimized operation. When the predicted value of the boost index is greater than or equal to the preset index threshold, it is considered that the static power angle and voltage stability margin boost capabilities of the photovoltaic power station at the next moment are relatively good, and the photovoltaic power station can provide higher-quality electric energy. At this time, the output of the MW-level generator can be appropriately reduced. The stability of the power grid can be effectively improved.

[0083] In one embodiment of the present specification, the preset index threshold may be any value between 0.6-0.7, preferably 0.637.

[0084] Based on the same general inventive concept, the present invention also protects a control device based on the static power angle and voltage stability margin of a photovoltaic power station, such as Figure 2 As shown, Figure 2 It is a structural schematic diagram of a control device based on the static power angle and voltage stability margin of a photovoltaic power station provided by an embodiment of the present invention. The control device based on the static power angle and voltage stability margin of a photovoltaic power station provided by the present invention is described below. The control device based on the static power angle and voltage stability margin of a photovoltaic power station described below and the control method based on the static power angle and voltage stability margin of a photovoltaic power station described above can be referred to each other.

[0085] The control device based on the static power angle and voltage stability margin of a photovoltaic power station includes an acquisition module 201, a time series module 202, an impact factor module 203, a first prediction module 204, a normalization module 205, a second prediction module 206 and a control module 207.

[0086] The acquisition module 201 acquires the conversion relationship between the pre-established improvement index of the static power angle and voltage stability margin of the photovoltaic power station and the improvement parameters of the static power angle and voltage stability margin of the photovoltaic power station; wherein the improvement parameters include the total input power and total output power of the grid-connected inverter in the photovoltaic power station, the total input power and total output power of the grid-following inverter, the inverter static power angle and the voltage of the MW-class synchronous machine in the grid-connected mode;

[0087] The time series module 202 establishes the time series of each boosting parameter;

[0088] The impact factor module 203 determines the impact factor of each boosting parameter at the next moment based on each boosting parameter;

[0089] The first prediction module 204 determines the predicted values ​​of the improved parameters of the static power angle and voltage stability margin of the photovoltaic power station at the next moment based on the time series and the influencing factors;

[0090] The normalization module 205 normalizes the predicted values ​​of the static power angle and voltage stability margin of the photovoltaic power station to obtain corresponding normalized values;

[0091] The second prediction module 206 determines the predicted value of the improvement index of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment based on the normalized value;

[0092] The control module 207 controls the power grid system of the photovoltaic power station based on the predicted value of the boost index.

[0093] Figure 3 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 3As shown, the electronic device may include: a processor 310, a communication interface 320, a memory 330 and a communication bus 340, wherein the processor 310, the communication interface 320 and the memory 330 communicate with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute the control method based on the static power angle and voltage stability margin of the photovoltaic power station.

[0094] In addition, the logic instructions in the above-mentioned memory 330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0095] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method based on the static power angle and voltage stability margin of the photovoltaic power station provided by the above methods.

[0096] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the control method based on the static power angle and voltage stability margin of the photovoltaic power station provided by the above methods.

[0097] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method based on the static power angle and voltage stability margin of a photovoltaic power station, characterized in that: include: Obtaining a conversion relationship between a pre-established improvement index of the static power angle and voltage stability margin of a photovoltaic power station and an improvement parameter of the static power angle and voltage stability margin of the photovoltaic power station; wherein the improvement parameters include the total input power and total output power of the grid-connected inverter in the photovoltaic power station, the total input power and total output power of the grid-following inverter, the inverter static power angle, and the voltage of the MW-class synchronous machine in the grid-connected mode; Establishing a time series of each of the boosting parameters; Based on the boost parameters, determining the impact factor of each boost parameter at the next moment; Based on the time series and the influencing factors, determining the predicted values ​​of the improved parameters of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment; Normalizing the predicted values ​​of the static power angle and voltage stability margin of the photovoltaic power station to obtain corresponding normalized values; Based on the normalized value, determining a predicted value of an improvement index of a static power angle and a voltage stability margin of the photovoltaic power station at a next moment; Based on the predicted value of the boost index, a power grid system of the photovoltaic power station is controlled.

2. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 1 is characterized in that: The conversion relationship is shown in the following formula (1): The time series is shown in the following formula (2): Among them, CI SPA-VSM is the static power angle and voltage stability margin improvement index of the photovoltaic power station, T1, T2, ..., T z ,...,T m is the time at a fixed time interval, where m is a natural number, z is the zth time, and z is a natural number, z∈{1,2,L,m}; N is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total input power of the grid-connected inverter in the photovoltaic power station, T z At the moment, the output power of the i-th grid-connected inverter in the photovoltaic power station is is the total output power of the grid-connected inverters in the photovoltaic power station; M is the number of grid-connected inverters in the photovoltaic power station, T z The input power of the i-th grid-connected inverter in the photovoltaic power station at the moment, It is the total output power of the grid-connected inverter in the photovoltaic power station; T z The output power of the i-th grid-connected inverter in the photovoltaic power station at the moment, is the total output power of the grid-type inverter in the photovoltaic power station; the allowable power factor of the photovoltaic inverter is (-cosφ, cosφ), T z The static power angle of the photovoltaic inverter at this moment.

3. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 2 is characterized in that: The impact factor can be expressed as the following formula (3): in, For the T z The influence factor of the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the moment on the static power angle and voltage stability margin improvement parameters of the photovoltaic power station at the next moment; P MDC-i,min The input power of the grid-connected inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P MAC-i,max The grid-type inverter output power is T1, T2, ..., T z ,...,T m The maximum value of the measured value at these m fixed time intervals; P LDC-i,min The input power of the grid-following inverter is T1, T2, ..., T z ,...,T m The minimum value of the measured values ​​at these m fixed time intervals; P LAC-i,max The output power of the grid-following inverter is T1, T2, ..., T z ,...,T m The maximum value of the measured values ​​at these m fixed time intervals.

4. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 3 is characterized in that: The predicted value of the improved parameter is shown in the following formula (4): in, T m+1 The predicted value of the total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total input power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The predicted value of the static power angle of the inverter at the moment; T m+1 The predicted value of the voltage in the grid-connected mode of the MW-class synchronous machine at the moment.

5. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 4 is characterized in that: The normalized value is shown in the following formula (5): in, T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total input power of the grid-connected inverter in the photovoltaic power station at the moment; T m+1 The normalized value of the predicted total output power of the grid-connected inverters in the photovoltaic power station at the moment; T m+1 The normalized value of the static power angle prediction value of the inverter at the moment; T m+1 The normalized value of the voltage prediction value in the MW-class synchronous machine grid-connected mode at time t; P MAC-i,min For T1, T2, ..., T z ,...,T m The minimum value of the measured output power of the grid-connected inverter in the m fixed time intervals; P LAC-i,min For T1, T2, ..., T z ,...,T m The minimum output power of the grid-connected inverter during these m fixed time intervals; P MDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; P LDC-i,max For T1, T2, ..., T z ,...,T m The maximum value of the grid-connected inverter input power during these m fixed time intervals; is the static power angle of the inverter at T1, T2, ..., T z ,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals; U SG,max , U SG,min The voltage of MW-class synchronous machine in grid-connected mode is T1, T2, ..., T z ,...,T m The maximum and minimum values ​​of the measured values ​​at these m fixed time intervals.

6. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 5 is characterized in that: The predicted value of the lifting index is shown in the following formula (6): in, To improve the predicted value of the index.

7. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 1, characterized in that: The method of controlling the power grid system of the photovoltaic power station based on the predicted value of the boost index includes: Comparing the predicted value of the improvement index with a preset index threshold; When the predicted value of the boost index is less than the preset index threshold, increasing the output power of the MW-class synchronous machine in the power grid to compensate for the output of the photovoltaic power station; When the predicted value of the boost index is greater than or equal to the preset index threshold, the output power of the MW-class synchronous machine in the power grid is reduced to compensate for the output of the photovoltaic power station.

8. The control method based on the static power angle and voltage stability margin of a photovoltaic power station according to claim 7 is characterized in that: The preset index threshold is 0.

637.

9. A control device based on the static power angle and voltage stability margin of a photovoltaic power station, characterized in that: include: An acquisition module is provided to acquire a conversion relationship between a pre-established improvement index of a photovoltaic power station static power angle and a voltage stability margin and an improvement parameter of a photovoltaic power station static power angle and a voltage stability margin; wherein the improvement parameter includes a total input power and a total output power of a grid-connected inverter in the photovoltaic power station, a total input power and a total output power of a grid-following inverter, an inverter static power angle, and a voltage of a MW-class synchronous machine in a grid-connected mode; A time series module, for establishing a time series of each of the boosted parameters; An impact factor module, based on each of the boost parameters, determines the impact factor of each boost parameter at the next moment; A first prediction module determines, based on the time series and the influencing factors, prediction values ​​of the improvement parameters of the static power angle and the voltage stability margin of the photovoltaic power station at the next moment; The normalization module normalizes the predicted values ​​of the static power angle and voltage stability margin of the photovoltaic power station to obtain the corresponding normalized values; A second prediction module determines, based on the normalized value, a prediction value of an improvement index of a static power angle and a voltage stability margin of the photovoltaic power station at a next moment; A control module controls a power grid system of the photovoltaic power station based on the predicted value of the boost index.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the control method based on the static power angle and voltage stability margin of the photovoltaic power station as described in any one of claims 1 to 8 above is implemented.

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