Calculation method and calculation device for grid-connected short-circuit ratio of new energy equipment

Abstract

The invention provides a calculation method and a calculation device for a grid-connected short-circuit ratio of new energy equipment. The calculation method comprises the steps of adjusting an output power value of new energy equipment, and collecting a first parameter of each branch equipment of a power grid system and a second parameter of the new energy equipment when the new energy equipment is at different output power values; calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different moments; and according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system, calculating to obtain a real-time grid-connected short-circuit ratio of the new energy equipment. According to the scheme provided by the invention, the grid-connected short-circuit ratio parameter of the new energy equipment in the current operation system state can be calculated, so that the operation characteristics of the new energy equipment can be accurately evaluated on line in real time.

Description

Technical Field

[0001] The present invention belongs to the field of electronic engineering technology, and specifically relates to a method for calculating a grid-connected short-circuit ratio of new energy equipment, a calculation device, an electronic device, a computer-readable storage medium, and a computer program product. Background Art

[0002] The short-circuit ratio is an important parameter that affects the operating performance of new energy equipment. Affected by the operation mode of the power grid system, the short-circuit ratio of new energy equipment on the grid changes continuously within a certain range. At present, the short-circuit ratio of new energy equipment on the grid is mainly calculated by simulating the short-circuit current of the power grid system through offline software, which cannot well reflect the dynamic changes of the short-circuit ratio of new energy equipment on the grid during actual operation. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a calculation method, a calculation device, a computer-readable storage medium and a computer program product capable of online and real-time calculation of the grid-connected short-circuit ratio. The solution provided by the present disclosure can calculate the online short-circuit ratio of the new energy grid-connected during the operation of the new energy equipment, and can provide important operation reference indicators for the operation of the new energy equipment.

[0004] In order to achieve the above-mentioned object, in a first aspect, the present disclosure provides a method for calculating the grid-connected short-circuit ratio of a new energy device, the method being applied to a power grid system, the power grid system comprising at least one group of branch circuit devices, the method comprising:

[0005] Adjusting the output power value of the new energy equipment, collecting the first parameters of each branch device of the power grid system and the second parameters of the new energy equipment when the new energy equipment has different output power values;

[0006] Calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times;

[0007] The real-time grid-connected short-circuit ratio of the new energy equipment is calculated based on the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

[0008] In some embodiments, calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times includes:

[0009] According to the first parameter and the second parameter collected at any four moments, the phase angle between the current at the collection end and the output voltage of the new energy station, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid are calculated at each of the said moments;

[0010] Calculate the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid;

[0011] According to the intermediate variable value, the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment are calculated;

[0012] According to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the collection end and the output voltage of the new energy station at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed under the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated.

[0013] In some embodiments, the first parameter includes the collecting terminal current and the collecting current amplitude, the voltage amplitude and the current amplitude of each branch device, the voltage phase angle and the current phase angle of each branch device relative to the grid voltage, and the speed at the power frequency;

[0014] The second parameters include the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy equipment, and the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage.

[0015] In some embodiments, according to the first parameter and the second parameter collected at any four moments, the phase difference between the current at the sink end and the output voltage of the new energy station, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid are calculated at each of the said moments, including:

[0016] For each of the four moments:

[0017] Obtain the current at the collecting end and the output voltage of the new energy station collected at the moment, and calculate the phase angle of the current at the collecting end and the output voltage of the new energy station at the moment based on the current at the collecting end and the output voltage of the new energy station;

[0018] Obtain the amplitude of the current at the collecting end and the amplitude of the output voltage of the new energy station collected at the moment, calculate the ratio of the amplitude of the current at the collecting end to the amplitude of the output voltage of the new energy station at the moment, and obtain the current coefficient at the moment;

[0019] Obtain the voltage amplitude and current amplitude of the new energy equipment running collected at this moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculate the equivalent resistance and equivalent inductance of the new energy equipment at this moment based on the voltage amplitude and current amplitude of the new energy equipment running, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage;

[0020] Obtain the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, collected at that moment; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, calculate the equivalent resistance and equivalent inductance of the mth branch device among the branch devices of the power grid system at that moment;

[0021] Calculate the conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices;

[0022] Based on the conductance and susceptance, calculate the equivalent resistance and equivalent inductance of m branches in the branch equipment of the power grid system at that moment after aggregation;

[0023] Based on the equivalent resistance and equivalent inductance of the new energy equipment at that moment, and the equivalent resistance and equivalent inductance of the m branch devices in the power grid system at that moment after aggregation, the aggregated equivalent resistance and aggregated equivalent inductance of each grid-connected branch are calculated.

[0024] In some embodiments, the intermediate variable value is calculated according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid, including:

[0025] Use the following third-party program group to calculate the intermediate variable value:

[0026] j1, j2, j3, and j4 are the four selected moments;

[0027] Among them, A j12 , B j12 , C j12 , A j34 , B j34 , C j34 is the intermediate variable;

[0028] sin(α ispj1 )、sin(αispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0029] cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0030] K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively;

[0031] L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

[0032] In some embodiments, according to the intermediate variable value, the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment are calculated, including:

[0033] The following fourth set of equations is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment:

[0034] α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

[0035] In some embodiments, according to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the latest collection end and the output voltage of the new energy station, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the power frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated, including:

[0036] The real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated using the fifth set of equations as follows:

[0037]

[0038] Among them, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspj Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj represents the aggregate equivalent inductance of each branch connected to the grid at the latest moment, w represents the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Represents the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

[0039] In some embodiments, the real-time grid-connected short-circuit ratio of the new energy equipment is calculated based on the equivalent resistance, equivalent impedance and equivalent voltage of the power grid system, specifically including:

[0040] Calculating the square of the equivalent resistance of the power grid system as a first value, and calculating the product of the square of the equivalent inductance of the power grid system and the square of the rotation speed at the power frequency as a second value;

[0041] Taking a square root of the sum of the first value and the second value to obtain a third value;

[0042] Calculate a ratio of the third value to square root of 2 times the rated current of the new energy equipment as a fourth value;

[0043] The ratio of the equivalent voltage of the power grid system to the fourth value is calculated to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

[0044] In a second aspect, the present disclosure further provides a device for calculating the short-circuit ratio of a new energy device connected to the grid, comprising:

[0045] A collection module, used for adjusting the output power value of the new energy equipment, collecting the first parameters of each branch device of the power grid system and the second parameter of the new energy equipment when the new energy equipment has different output power values;

[0046] A first calculation module, used for calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times;

[0047] The second calculation module is used to calculate the real-time grid-connected short-circuit ratio of the new energy equipment according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

[0048] In some embodiments, the first computing module includes a first computing submodule, a second computing submodule, a third computing submodule, and a fourth computing submodule:

[0049] The first calculation submodule is used to calculate the phase angle between the current at the collection end and the output voltage of the new energy station at each time, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid according to the first parameter and the second parameter collected at any four times;

[0050] The second calculation submodule is used to calculate the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid;

[0051] The third calculation submodule is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment according to the intermediate variable value;

[0052] The fourth calculation submodule is used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment.

[0053] In some embodiments, the first parameter includes the collecting terminal current and the collecting current amplitude, the voltage amplitude and the current amplitude of each branch device, the voltage phase angle and the current phase angle of each branch device relative to the grid voltage, and the speed at the power frequency;

[0054] The second parameters include the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy equipment, and the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage.

[0055] In some embodiments, the first computing submodule is specifically configured to perform the following steps:

[0056] For each of the four moments:

[0057] Obtain the current at the collecting end and the output voltage of the new energy station collected at the moment, and calculate the phase angle of the current at the collecting end and the output voltage of the new energy station at the moment based on the current at the collecting end and the output voltage of the new energy station;

[0058] Obtain the amplitude of the current at the collecting end and the amplitude of the output voltage of the new energy station collected at the moment, calculate the ratio of the amplitude of the current at the collecting end to the amplitude of the output voltage of the new energy station at the moment, and obtain the current coefficient at the moment;

[0059] Obtain the voltage amplitude and current amplitude of the new energy equipment running collected at this moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculate the equivalent resistance and equivalent inductance of the new energy equipment at this moment based on the voltage amplitude and current amplitude of the new energy equipment running, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage;

[0060] Obtain the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, collected at that moment; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, calculate the equivalent resistance and equivalent inductance of the mth branch device among the branch devices of the power grid system at that moment;

[0061] Calculate the conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices;

[0062] Based on the conductance and susceptance, calculate the equivalent resistance and equivalent inductance of m branches in the branch equipment of the power grid system at that moment after aggregation;

[0063] Based on the equivalent resistance and equivalent inductance of the new energy equipment at that moment; and the equivalent resistance and equivalent inductance of m branch devices in the branch devices of the power grid system at that moment after aggregation, the aggregated equivalent resistance of each grid-connected branch and the aggregated equivalent inductance of each grid-connected branch are calculated, where m is a positive integer.

[0064] In some embodiments, the second calculation submodule is specifically used to calculate the intermediate variable value using the following third-party program group:

[0065]

[0066] Among them, j1, j2, j3, and j4 are four selected moments, A j12 , B j12 , C j12 , A j34 , B j34 , C j34 is the intermediate variable;

[0067] sin(α ispj1 )、sin(α ispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0068] cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0069] K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively;

[0070] L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

[0071] In some embodiments, the third calculation submodule is specifically used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment using the following fourth equation group:

[0072] α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

[0073] In some embodiments, the fourth calculation submodule is specifically used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system using the following fifth set of equations:

[0074]

[0075] Among them, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspj Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj Indicates the latest aggregate equivalent inductance of each branch connected to the grid, ω indicates the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Indicates the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

[0076] In some embodiments, the second computing module is specifically configured to perform the following steps:

[0077] Calculating the square of the equivalent resistance of the power grid system as a first value, and calculating the product of the square of the equivalent inductance of the power grid system and the square of the rotation speed at the power frequency as a second value;

[0078] Taking a square root of the sum of the first value and the second value to obtain a third value;

[0079] Calculate a ratio of the third value to square root of 2 times the rated current of the new energy equipment as a fourth value;

[0080] The ratio of the equivalent voltage of the power grid system to the fourth value is calculated to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

[0081] In a third aspect, the present disclosure further provides an electronic device, comprising 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 computing method of the first aspect described above is implemented.

[0082] In a fourth aspect, the present disclosure further provides a computer-readable storage medium storing a computer program for executing the computing method of the first aspect.

[0083] In a fifth aspect, the present disclosure further provides a computer program product, including a computer program / instruction, which implements the steps of the computing method of the first aspect when the computer program / instruction is executed by a processor.

[0084] The present disclosure collects the first parameters of each branch device of the power grid system and the second parameters of the new energy device under different output power values ​​of the new energy device, and calculates the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the collected first and second parameters, and calculates the real-time grid-connected short-circuit ratio of the new energy device according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system. The grid-connected short-circuit ratio calculation method provided by the present disclosure can calculate the online short-circuit ratio of the new energy grid during the operation of the new energy device. Compared with the traditional solution of calculating the short-circuit current of the power grid system by simulating offline software, the calculation method provided by the present disclosure can well reflect the dynamic change of the short-circuit ratio during the actual operation of the new energy device, thereby realizing the online real-time and accurate evaluation of the operating characteristics of the new energy device, and can provide important operating reference indicators for the operation of the new energy device. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0086] Figure 1 A flow chart of a method for calculating the short-circuit ratio of a new energy device connected to the grid provided by an embodiment of the present disclosure;

[0087] Figure 2 A schematic diagram of an equivalent circuit of a new energy equipment grid connection point provided by an embodiment of the present disclosure;

[0088] Figure 3 A circuit diagram of a new energy station including a main transformer provided in an embodiment of the present disclosure;

[0089] Figure 4 A method flow chart of step S102 provided in an embodiment of the present disclosure;

[0090] Figure 5 A structural block diagram of a device for calculating the short-circuit ratio of a new energy device connected to the grid provided by an embodiment of the present disclosure;

[0091] Figure 6 A structural block diagram of a first computing module provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0092] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail and completely in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0093] In a first aspect, an embodiment of the present disclosure provides a method for calculating the grid-connected short-circuit ratio of new energy equipment.

[0094] Figure 1 A flow chart of a method for calculating the short-circuit ratio of a new energy device connected to the grid provided in an embodiment of the present disclosure, the calculation method can be applied to a power grid system, the power grid system including at least one group of branch devices. Specifically, the whole composed of substations and transmission and distribution lines of various voltages in the power system is called a power grid system, which includes three units: substation, transmission, and distribution. The task of the power grid system is to transmit and distribute electric energy and change the voltage. In the power grid system, new energy equipment generally refers to equipment related to renewable energy power generation, which may include but is not limited to: Wind turbines: equipment that converts wind energy into electric energy, including onshore wind power and offshore wind power equipment. Photovoltaic power generation equipment: equipment that converts sunlight into electric energy using solar panels. Energy storage equipment: such as a battery energy storage system, used to store excess electric energy for emergency use. It should be noted that the branch equipment in the power grid system is also a type of new energy equipment. In order to distinguish between the original new energy equipment in the power grid system and the new energy equipment to be incorporated into the power grid system, in the embodiments of the present disclosure, the new energy equipment specifically refers to the new energy equipment to be incorporated into the power grid system, and the branch equipment specifically refers to the new energy equipment that has been incorporated into the power grid system. The present disclosure aims to study the impact of new energy equipment on the operation of various power equipment in the power grid system after it is incorporated into the power grid system. After the new energy equipment is incorporated into the power grid system, the new energy equipment and various branch equipment are all new energy equipment in the power grid system.

[0095] Figure 2 A schematic diagram of an equivalent circuit of a new energy equipment grid connection point provided by an embodiment of the present disclosure; Figure 3 The circuit diagram of a new energy station with a main transformer is provided in an embodiment of the present disclosure. Figure 2-3 As shown, R x With wL x The branch where it is located can represent the new energy equipment connected to the grid, where R x Indicates the resistance of new energy equipment, L x represents the inductance of new energy equipment, w represents the speed at the power frequency; R d1 With wL d1 The branch road 、 Rd2 With wL d2 The branch road … R dm With wL dm The branches where they are located represent multiple branch devices of the power grid system. dm Indicates the resistance of the mth branch device, L dm represents the inductance of the mth branch device, and m is a positive integer. Wherein, the power grid system provided by the embodiment of the present disclosure includes at least one branch device, that is, m is a positive integer greater than or equal to 1. Figure 2 As shown in the figure, Rs represents the equivalent resistance of the power grid system after the new energy equipment is connected to the grid, Ls represents the equivalent inductance of the power grid system after the new energy equipment is connected to the grid, and U s *sin(wt+α us ) represents the equivalent voltage of the power grid system after the new energy equipment is connected to the grid. Figure 3 As shown, U p *sin(wt+α up ) represents the output voltage of the new energy station.

[0096] like Figure 1 to Figure 3 As shown, the calculation method can be applied to a power grid system, which includes at least one group of branch devices. The calculation method specifically includes the following steps:

[0097] S101, adjusting the output power value of the new energy equipment, collecting the first parameters of each branch equipment of the power grid system and the second parameters of the new energy equipment when the new energy equipment has different output power values.

[0098] Specifically, different output powers of new energy equipment can represent different operating states of new energy equipment. Taking the new energy equipment as a solar power generation equipment as an example, the output power of the solar power generation equipment (new energy equipment) can be adjusted by controlling the load of the solar power generation equipment. For example, when the load of the solar power generation equipment is X1, the corresponding output power of the solar power generation equipment is P1. When the load of the solar power generation equipment is increased so that the load of the solar power generation equipment is X2, the corresponding output power of the solar power generation equipment is P2, and so on. After the new energy equipment is connected to the power grid system for grid connection, the operating state of the new energy equipment will also affect the operating state of each branch equipment in the power grid system. The embodiment of the present disclosure represents the operating state of each branch equipment in the power grid system by the first parameter of each branch equipment in the power grid system, and represents the operating state of the new energy equipment by the second parameter of the new energy equipment.

[0099] Optionally, when adjusting the output power value of the new energy device and collecting the first parameter and the second parameter, the first parameter of each branch device of the power grid system and the second parameter of the new energy device can be collected continuously, or interval collection can be performed as needed, and the present disclosure does not limit this. It should be noted that the collected first parameter and second parameter at least include the operating status corresponding to each branch device of the power grid system and the new energy device at the latest moment. In this way, the real-time grid-connected short-circuit ratio of the new energy device can be calculated based on the collected first parameter and second parameter.

[0100] In some embodiments, the first parameter includes the current at the collecting end and the amplitude of the collecting current, the voltage amplitude and current amplitude of each branch device, the voltage phase angle and current phase angle of each branch device relative to the grid voltage, and the speed at the power frequency. Among them, the collecting end current refers to the current at the collection point of each branch device and the new energy device in the power grid system, and the speed at the power frequency is generally 314.

[0101] In some embodiments, the second parameter includes the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy device, and the voltage phase angle and current phase angle of the new energy device relative to the grid voltage. Among them, the output voltage of the new energy station refers to the total voltage of the substation transmitting power to the power grid system.

[0102] Specifically, by adjusting the different output power values ​​of new energy equipment (j=1,2,3...n, S=P+jQ, P is active power, Q is reactive power), and through the online recording equipment, the output current of the new energy equipment at different operating states j (j=1,2,3...n) of the corresponding new energy equipment can be collected. The output voltages of new energy equipment are The currents of each branch device of the power grid system are (m represents each branch of the power grid system, m is a positive integer, for example, m can be 1, 2, 3...), the current at the collection end is The grid-connected voltages of new energy equipment are The output voltages of new energy stations are

[0103] Among them, the output voltage and output current waveforms of the new energy equipment are Among them, U xj ,I xj are the amplitudes of the output voltage and output current of the new energy equipment at different operating states j (j=1, 2, 3...n) at different times, α uxj , α ixjThey are the voltage and current phase angles of the new energy equipment relative to the grid voltage when the new energy equipment is running at different times. In addition, in order to reduce the impact of the grid system fluctuation when the new energy equipment is connected to the grid, the value of n should have sufficient sample data.

[0104] For each branch device of the power grid system, the voltage and current waveforms of the mth branch device at the grid connection point of the new energy equipment are respectively Among them U djm ,I djm are the voltage and current amplitude of the mth branch of the grid connection point of the new energy equipment under the different operating states j (j=1,2,3...n) of the new energy equipment at different times, α udjm , α idjm They are the voltage and current phase angles of the mth branch of the grid-connected point of the new energy equipment relative to the grid-connected voltage under the operating state j (j=1, 2, 3...n) of the new energy equipment at different times. In order to reduce the impact of system fluctuations, the value of n has sufficient sample data. In addition, for convenience, the embodiment of the present disclosure takes the power grid system with one branch device as an example for explanation. If there are m branch devices in the power grid system, multiple branch devices can be aggregated into one branch device according to the impedance characteristics.

[0105] New energy station output voltage U pj is the output voltage amplitude of the new energy station, wt+α upj It is the output voltage phase of the new energy station.

[0106] S102: Calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times.

[0107] Specifically, the system equivalent voltage is the system voltage equivalent to the operation process of the new energy equipment. The system equivalent voltage changes with the operation mode of the power grid system, but in a fixed power grid system operation state, the system voltage amplitude and phase remain stable. Assume that the system equivalent voltage is U s is the amplitude of the system equivalent voltage, wt+α usj is the phase of the system equivalent voltage, α usj is the phase angle of the system equivalent voltage, and w is the speed at the power frequency, which is 314. Similarly, the system equivalent resistance and system equivalent inductance are also the system resistance and system inductance equivalent to the operation process of new energy equipment. The system equivalent resistance and system equivalent inductance will also change with the operation mode of the power grid system.

[0108] Since the collected first parameter and second parameter at least include the operating status of each branch device and the corresponding new energy device of the power grid system at the latest moment, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system can be calculated based on the collected first parameter and second parameter.

[0109] S103. Calculate the real-time grid-connected short-circuit ratio of the new energy equipment according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

[0110] Specifically, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system represent the latest real-time operating status of the new energy equipment. The present disclosure can calculate the real-time grid-connected short-circuit ratio of the new energy equipment based on the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

[0111] The present disclosure collects the first parameters of each branch device of the power grid system and the second parameters of the new energy device under different output power values ​​of the new energy device, and calculates the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the collected first and second parameters, and calculates the real-time grid-connected short-circuit ratio of the new energy device according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system. The grid-connected short-circuit ratio calculation method provided by the present disclosure can calculate the online short-circuit ratio of the new energy grid during the operation of the new energy device. Compared with the traditional solution of calculating the short-circuit current of the power grid system by simulating offline software, the calculation method provided by the present disclosure can well reflect the dynamic change of the short-circuit ratio during the actual operation of the new energy device, thereby realizing the online real-time and accurate evaluation of the operating characteristics of the new energy device, and can provide important operating reference indicators for the operation of the new energy device.

[0112] Figure 4 A method flow chart of step S102 provided in an embodiment of the present disclosure. Figure 4 As shown, in some embodiments, step S102, calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times, specifically includes:

[0113] S1021. Calculate, based on the first parameter and the second parameter collected at any four moments, the phase angle between the current at the collection end and the output voltage of the new energy station, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each grid-connected branch, and the aggregate equivalent inductance of each grid-connected branch at each of the said moments.

[0114] S1022. Calculate the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid.

[0115] S1023. Calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment according to the intermediate variable value.

[0116] S1024. Calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system based on the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase difference between the equivalent voltage of the system and the collected current at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment.

[0117] It is understandable that when calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system in step S102, the first parameter and the second parameter at more than four moments can also be selected for calculation, so that the calculation error of the first parameter and the second parameter due to acquisition error or other errors can be reduced, and the accuracy of the calculation can be improved. In addition, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system can also be obtained by other calculation methods based on the first parameter and the second parameter, and the present disclosure does not limit this.

[0118] In some embodiments, step S1021 calculates the phase difference between the current at the sink end and the output voltage of the new energy station at each time, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid according to the first parameter and the second parameter collected at any four times, specifically including:

[0119] For each of the four moments:

[0120] Step S10211, obtaining the current at the collecting end and the output voltage of the new energy station collected at this moment, and calculating the phase angle of the current at the collecting end and the output voltage of the new energy station at this moment based on the current at the collecting end and the output voltage of the new energy station.

[0121] That is, calculate the current at the collecting end of the new energy equipment at different operating states j (j = 1, 2, 3...n) at different times Output voltage of new energy station The phase difference between them is α isp1 , α isp2 ...α ispj .

[0122] Step S10212, obtain the amplitude of the current at the collection end and the amplitude of the output voltage of the new energy station collected at this moment, calculate the ratio of the amplitude of the current at the collection end to the amplitude of the output voltage of the new energy station at this moment, and obtain the current coefficient at this moment.

[0123] That is, calculate the current coefficient K of the new energy equipment under different operating states j (j = 1, 2, 3...n) at different times ij =I sj / U pj , U pj ,I sj They are respectively the amplitude of the output voltage of the new energy station and the amplitude of the current at the collection end.

[0124] Step S10213, obtain the voltage amplitude and current amplitude of the new energy equipment collected at this moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculate the equivalent resistance and equivalent inductance of the new energy equipment at this moment based on the voltage amplitude and current amplitude of the new energy equipment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage.

[0125] Among them, the equivalent resistance R of the new energy equipment at different operating states j (j = 1, 2, 3...n) is set xj (j=1,2,3...n), equivalent inductance L xj (j=1,2,3...n), we can get R xj =U xj / I xj *cos(α uxj -α ixj ), L xj =U xj / I xj *sin(α uxj -α ixj ) / w;U xj Indicates the voltage amplitude of the new energy equipment operation, I xj represents the current amplitude, α uxj Indicates the voltage phase angle of the new energy equipment relative to the grid voltage; α ixj Indicates the current phase angle of new energy equipment relative to the grid voltage.

[0126] Step S10214, obtain the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, calculate the equivalent resistance and equivalent inductance of the mth branch device in the branch devices of the power grid system at that moment.

[0127] Specifically, the equivalent resistance R of the mth branch in other branches under the operating state j (j=1, 2, 3...n) of the new energy equipment at different times is set. dmj , equivalent inductance I dmj , we can calculate R dmj =U dmj / I dmj *cos(α udmj -α idmj ), L dmj =U dmj / I dmj *sin(α udmj -α idmj ) / w;U dmj Indicates the voltage amplitude of the mth branch equipment at the grid connection point of the new energy equipment, I dmj Indicates the current amplitude of the mth branch equipment at the grid connection point of the new energy equipment, α udmj Represents the voltage phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, α idmj It represents the current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage.

[0128] Step S10215: Calculate the conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices.

[0129] Specifically, the equivalent impedance Z of the branch equipment of the power grid system is set at different operating states j (j=1, 2, 3...n) of the new energy equipment at different times. dj =R dj +j*ω*L dj , the equivalent admittance Y of the mth branch equipment dmj =G dmj +J*B dmj =1 / (R dmj +j*L dmj )(J is an imaginary unit), set the equivalent resistance R of the mth branch in the branch equipment of the power grid system under the operating state j (j=1,2,3...n) of the new energy equipment at different times dmj , equivalent inductance I dmj , from which the conductivity G of the mth branch device in the branch device of the power grid system can be calculated dmj and electrosusceptor B dmj .

[0130] Step S10216: Based on the conductance and susceptance, calculate the equivalent resistance and equivalent inductance of the m branches in the branch equipment of the power grid system at that moment after aggregation.

[0131] Specifically, under the setting of the operating state j (j=1, 2, 3...n) of the new energy equipment at different times, the equivalent resistance R after the aggregation of m branches in the branch equipment of the power grid system at that time is calculated. dj =(G d1j +G d2j +...+G dmj ) / (G d1j +G d2j +...+G dmj )*(G d1j +G d2j +...+G dmj )+(B d1j +B d2j +...+B dmj )*(B d1j +B d2j +...+B dmj ));

[0132] And calculate the equivalent inductance of m branches after aggregation in the branch equipment of the power grid system at that moment

[0133] L dj =-(B d1j +B d2j +...+B dmj ) / ((G d1j +G d2j +...+G dmj )*(G d1j +G d2j +...+G dmj )+(B d1j +B d2j +...+B dmj )*(B d1j +B d2j +...+B dmj )) / ω.

[0134] Step S10217, based on the equivalent resistance and equivalent inductance of the new energy equipment at this moment; and the equivalent resistance and equivalent inductance of the m branch devices in the branch devices of the power grid system at this moment after aggregation, calculate the aggregated equivalent resistance of each grid-connected branch and the aggregated equivalent inductance of each grid-connected branch.

[0135] Specifically, the aggregate equivalent impedance Z of the branch equipment under the operating state j (j=1, 2, 3...n) of the new energy equipment at different times is set. Mj =(R xj +j*ω*L xj ) / / (R dj +j*ω*L dj )=R Mj +j*ω*LMj , based on the aggregate equivalent impedance Z of the branch equipment Mj The aggregate equivalent resistance R of each branch connected to the grid can be calculated Mj , the aggregate equivalent inductance of each branch of the grid is L Mj .

[0136] In the embodiment of the present disclosure, the equivalent resistance and equivalent inductance of the new energy equipment and each branch equipment at the moment are calculated based on the collected first parameter and second parameter; thereby obtaining the aggregate equivalent resistance and aggregate equivalent inductance of each branch connected to the grid, so that the calculation result is more accurate. In addition, step S1021 can also be obtained based on other methods, which is not limited by the present disclosure.

[0137] In some embodiments, step S1022, calculating the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid, specifically includes: calculating the intermediate variable value using the following third-party program group:

[0138] j1, j2, j3, and j4 are the four selected moments;

[0139] Among them, sin(α ispj1 )、sin(α ispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0140] cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0141] K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively;

[0142] L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

[0143] It is understandable that the intermediate variable may also be obtained in other ways according to the circuit relationship, and the present disclosure does not limit this.

[0144] In some embodiments, step S1023, according to the intermediate variable value, calculates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment, specifically including:

[0145] The following fourth set of equations is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment:

[0146] α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

[0147] In some embodiments, step S1024, according to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the latest collection end and the output voltage of the new energy station, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the power frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment, calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system, specifically including:

[0148] The real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated using the fifth set of equations as follows:

[0149]

[0150] Among them, j is the latest time, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspj Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj represents the aggregate equivalent inductance of each branch connected to the grid at the latest moment, w represents the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Indicates the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

[0151] Specifically, the embodiments of the present disclosure are applicable to the scenario of a strong power grid, that is, when the new energy equipment is in operation at different times, the output voltage of the new energy station is not affected by the operation state of the new energy equipment, that is, the amplitude and phase difference between the system equivalent voltage and the output voltage of the new energy station remain constant, that is, α usp1 =α usp2 =... =α uspj =α usp , U s1 =U s2 =...=U sj =U s , U p1 =U p2 =...=U pj =U p . The matrix relationship equation is obtained

[0152]

[0153] From the above content and matrix equation, we can see that in addition to R s , L s , U s , α usp , K v is an unknown quantity, and the other variables can be obtained by the data processing method under the operating state j (j=1,2,3...n) of the new energy equipment at different times, that is, the first parameter and the second parameter collected at any four times are selected according to the above step S1021 and calculated. Further, according to step S1023, α can be calculated usp , K v , and α usp , K v Substituting into the above equations, we can get the real-time equivalent resistance R of the power grid system. s , equivalent impedance L s And the equivalent voltage U s .

[0154] In some embodiments, before step S1024, the calculation method further includes: determining whether the output voltage of the new energy station is affected by the operating state of the new energy equipment at different times, that is, determining whether the amplitude and phase difference between the system equivalent voltage and the output voltage of the new energy station remain constant. Only when the above conditions are met can the above steps be executed to calculate the real-time equivalent resistance R of the power grid system. s , equivalent impedance L s And the equivalent voltage U s .

[0155] In some embodiments, step S103, calculating the real-time grid-connected short-circuit ratio of the new energy equipment according to the equivalent resistance, equivalent impedance and equivalent voltage of the power grid system, specifically includes:

[0156] Calculating the square of the equivalent resistance of the power grid system as a first value, and calculating the product of the square of the equivalent inductance of the power grid system and the square of the rotation speed at the power frequency as a second value;

[0157] Taking a square root of the sum of the first value and the second value to obtain a third value;

[0158] Calculate a ratio of the third value to square root of 2 times the rated current of the new energy equipment as a fourth value;

[0159] The ratio of the equivalent voltage of the power grid system to the fourth value is calculated to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

[0160] That is, when the new energy equipment is connected to the grid, R s , L s , U s After the value is set, the online real-time grid-connected short-circuit ratio SCR is

[0161] SCR=U s / sqrt(R s *R s +ω*ω*L s *L s ) / sqrt2 / I XN , I XN Rated current of new energy equipment.

[0162] Among them, during the actual operation process, the SCR is generally greater than 5, and the amplitude and phase of the output voltage sent by the new energy station are less affected by the state changes of the new energy equipment.

[0163] The present disclosure collects the first parameters of each branch device of the power grid system and the second parameters of the new energy device under different output power values ​​of the new energy device, and calculates the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the collected first and second parameters, and calculates the real-time grid-connected short-circuit ratio of the new energy device according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system. The grid-connected short-circuit ratio calculation method provided by the present disclosure can calculate the online short-circuit ratio of the new energy grid during the operation of the new energy device. Compared with the traditional solution of calculating the short-circuit current of the power grid system by simulating offline software, the calculation method provided by the present disclosure can well reflect the dynamic change of the short-circuit ratio during the actual operation of the new energy device, thereby realizing the online real-time and accurate evaluation of the operating characteristics of the new energy device, and can provide important operating reference indicators for the operation of the new energy device.

[0164] In the second aspect, based on the same inventive concept, the disclosed embodiment also provides a device for calculating the grid-connected short-circuit ratio of new energy equipment. Figure 5 The structure block diagram of a calculation device 100 for the short-circuit ratio of a new energy device connected to the grid provided by an embodiment of the present disclosure. Figure 5 As shown, the computing device 100 includes a collection module 30 , a first computing module 40 and a second computing module 50 .

[0165] The acquisition module 30 is used to adjust the output power value of the new energy equipment, and to acquire the first parameters of each branch device of the power grid system and the second parameters of the new energy equipment when the new energy equipment has different output power values.

[0166] The first calculation module 40 is used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times.

[0167] The second calculation module 50 is used to calculate the real-time grid-connected short-circuit ratio of the new energy equipment according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

[0168] Figure 6 FIG. 1 is a structural block diagram of a first computing module provided in an embodiment of the present disclosure. Figure 6 As shown, in some embodiments, the first computing module 40 includes a first computing submodule 41 , a second computing submodule 42 , a third computing submodule 43 and a fourth computing submodule 44 .

[0169] Among them, the first calculation submodule 41 is used to calculate the phase angle between the collection end current and the output voltage of the new energy station at each moment, the new energy equipment current coefficient, the aggregate equivalent resistance of each grid-connected branch, and the aggregate equivalent inductance of each grid-connected branch based on the first parameter and the second parameter collected at any four moments.

[0170] The second calculation submodule 42 is used to calculate the intermediate variable value according to the phase angle between the collection end current and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each grid-connected branch.

[0171] The third calculation submodule 43 is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment according to the intermediate variable value.

[0172] The fourth calculation submodule 44 is used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the collection end and the output voltage of the new energy station at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment.

[0173] In some embodiments, the first parameter includes the collecting end current and the amplitude of the collecting current, the voltage amplitude and current amplitude of each branch device, the voltage phase angle and current phase angle of each branch device relative to the grid voltage, and the speed at the industrial frequency; the second parameter includes the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy device, and the voltage phase angle and current phase angle of the new energy device relative to the grid voltage.

[0174] In some embodiments, the first calculation submodule 41 is specifically used for: for each of the four arbitrary moments: obtaining the current at the collecting end and the output voltage of the new energy station collected at that moment, and calculating the phase angle of the current at the collecting end and the output voltage of the new energy station at that moment based on the current at the collecting end and the output voltage of the new energy station; obtaining the amplitude of the current at the collecting end and the amplitude of the output voltage of the new energy station collected at that moment, calculating the ratio of the amplitude of the current at the collecting end to the amplitude of the output voltage of the new energy station at that moment, and obtaining the current coefficient at that moment; obtaining the voltage amplitude and current amplitude of the new energy equipment running at that moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculating the equivalent resistance and equivalent inductance of the new energy equipment at that moment based on the voltage amplitude and current amplitude of the new energy equipment running, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage; obtaining the voltage amplitude and The current amplitude, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices of the power grid system at that moment are calculated; according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices The conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment are calculated; based on the conductance and susceptance, the equivalent resistance and equivalent inductance of the m branches in the branch devices of the power grid system at that moment are calculated; based on the equivalent resistance and equivalent inductance of the new energy equipment at that moment; and the equivalent resistance and equivalent inductance of the m branch devices in the branch devices of the power grid system at that moment, the aggregated equivalent resistance of each branch connected to the grid and the aggregated equivalent inductance of each branch connected to the grid are calculated.

[0175] In some embodiments, the second calculation submodule 42 is specifically used for:

[0176] Use the following third-party program group to calculate the intermediate variable value:

[0177] j1, j2, j3, and j4 are the four selected moments;

[0178] Among them, A j12 , B j12 , C j12 , A j34 , B j34 , C j34 is the intermediate variable;

[0179] sin(α ispj1 )、sin(α ispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0180] cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively;

[0181] K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively;

[0182] L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

[0183] In some embodiments, the third calculation submodule 43 is specifically used for:

[0184] The following fourth set of equations is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment:

[0185] α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

[0186] In some embodiments, the fourth calculation submodule 44 is specifically used to:

[0187] The real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated using the fifth set of equations as follows:

[0188]

[0189] Among them, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspjIndicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj represents the aggregate equivalent inductance of each branch connected to the grid at the latest moment, w represents the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Indicates the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

[0190] In some embodiments, the second calculation module 50 is specifically used to calculate the square of the equivalent resistance of the power grid system as the first value, and to calculate the product of the square of the equivalent inductance of the power grid system and the square of the rotational speed at the industrial frequency as the second value; to obtain the third value by taking the square root of the sum of the first value and the second value; to calculate the ratio of the third value to the square root of 2 times the rated current of the new energy equipment as the fourth value; to calculate the ratio of the equivalent voltage of the power grid system to the fourth value to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

[0191] It can be understood that the specific details of the computing device provided in the embodiment of the present disclosure can refer to the specific details of the computing method embodiment of the first aspect mentioned above, and will not be repeated here.

[0192] In a third aspect, an embodiment of the present disclosure further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described in any one of the first aspects is implemented.

[0193] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program of the method described in any one of the first aspects above.

[0194] In a fifth aspect, an embodiment of the present disclosure further provides a computer program product, comprising a computer program / instructions, which, when executed by a processor, implement the steps of any one of the methods described in the first aspect above.

[0195] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0196] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0197] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0198] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0199] The present disclosure uses specific embodiments to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method of the present disclosure and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present disclosure, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present disclosure.

Claims

1. A method for calculating the short-circuit ratio of a new energy device connected to the grid, characterized in that: The method is applied to a power grid system, the power grid system includes at least one group of branch circuit devices, and the method includes: Adjusting the output power value of the new energy equipment, and collecting the first parameters of each branch device of the power grid system and the second parameter of the new energy equipment when the new energy equipment has different output power values; Calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times; The real-time grid-connected short-circuit ratio of the new energy equipment is calculated based on the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

2. The method according to claim 1, characterized in that Calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times includes: According to the first parameter and the second parameter collected at any four moments, the phase angle between the current at the collection end and the output voltage of the new energy station, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid are calculated at each of the said moments; Calculate the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid; According to the intermediate variable value, the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment are calculated; According to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the collection end and the output voltage of the new energy station at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed under the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated.

3. The method according to claim 2, characterized in that The first parameters include the collecting end current and the collecting current amplitude, the voltage amplitude and current amplitude of each branch device, the voltage phase angle and current phase angle of each branch device relative to the grid voltage, and the speed at the power frequency; The second parameters include the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy equipment, and the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage.

4. The method according to claim 3, characterized in that According to the first parameter and the second parameter collected at any four moments, the phase difference between the current at the collection end and the output voltage of the new energy station at each moment, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid are calculated, including: For each of the four moments: Obtain the current at the collecting end and the output voltage of the new energy station collected at the moment, and calculate the phase angle of the current at the collecting end and the output voltage of the new energy station at the moment based on the current at the collecting end and the output voltage of the new energy station; Obtain the amplitude of the current at the collecting end and the amplitude of the output voltage of the new energy station collected at the moment, calculate the ratio of the amplitude of the current at the collecting end to the amplitude of the output voltage of the new energy station at the moment, and obtain the current coefficient at the moment; Obtain the voltage amplitude and current amplitude of the new energy equipment running collected at this moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculate the equivalent resistance and equivalent inductance of the new energy equipment at this moment based on the voltage amplitude and current amplitude of the new energy equipment running, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage; Obtain the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, collected at that moment; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, calculate the equivalent resistance and equivalent inductance of the mth branch device among the branch devices of the power grid system at that moment; Calculate the conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices; Based on the conductance and susceptance, calculate the equivalent resistance and equivalent inductance of m branches in the branch equipment of the power grid system at that moment after aggregation; Based on the equivalent resistance and equivalent inductance of the new energy equipment at that moment; and the equivalent resistance and equivalent inductance of m branch devices in the branch devices of the power grid system at that moment after aggregation, the aggregated equivalent resistance of each grid-connected branch and the aggregated equivalent inductance of each grid-connected branch are calculated, where m is a positive integer.

5. The method according to claim 2, characterized in that: According to the phase angle between the current at the collecting end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid, the intermediate variable value is calculated, including: Use the following third-party program group to calculate the intermediate variable value: Among them, j1, j2, j3, and j4 are four selected moments, A j12 , B j12 , C j12 , A j34 , B j34 , C j34 is the intermediate variable; sin(α ispj1 )、sin(α ispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively; cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively; K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively; L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

6. The method according to claim 5, characterized in that According to the intermediate variable value, the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment are calculated, including: The following fourth set of equations is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment: α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

7. The method according to claim 2, characterized in that According to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the latest collection end and the output voltage of the new energy station, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the power frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment, the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated, including: The real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system are calculated using the fifth set of equations as follows: Among them, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspj Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj Indicates the latest aggregate equivalent inductance of each branch connected to the grid, ω indicates the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Represents the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

8. The method according to claim 1, characterized in that The calculating of the real-time grid-connected short-circuit ratio of the new energy equipment according to the equivalent resistance, equivalent impedance and equivalent voltage of the power grid system specifically includes: Calculating the square of the equivalent resistance of the power grid system as a first value, and calculating the product of the square of the equivalent inductance of the power grid system and the square of the rotation speed at the power frequency as a second value; Taking a square root of the sum of the first value and the second value to obtain a third value; Calculate a ratio of the third value to square root of 2 times the rated current of the new energy equipment as a fourth value; The ratio of the equivalent voltage of the power grid system to the fourth value is calculated to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

9. A device for calculating the short-circuit ratio of a new energy device connected to the grid, characterized in that: The device comprises: A collection module, used for adjusting the output power value of the new energy equipment, and collecting the first parameters of each branch device of the power grid system and the second parameter of the new energy equipment when the new energy equipment has different output power values; A first calculation module, used for calculating the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the first parameter and the second parameter collected at different times; The second calculation module is used to calculate the real-time grid-connected short-circuit ratio of the new energy equipment according to the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system.

10. The device according to claim 9, characterized in that The first calculation module includes a first calculation submodule, a second calculation submodule, a third calculation submodule and a fourth calculation submodule: The first calculation submodule is used to calculate the phase angle between the current at the collection end and the output voltage of the new energy station at each time, the current coefficient of the new energy equipment, the aggregate equivalent resistance of each branch connected to the grid, and the aggregate equivalent inductance of each branch connected to the grid according to the first parameter and the second parameter collected at any four times; The second calculation submodule is used to calculate the intermediate variable value according to the phase angle between the current at the collection end and the output voltage of the new energy station at each of the four arbitrary moments, the current coefficient of the new energy equipment, and the aggregate equivalent inductance of each branch connected to the grid; The third calculation submodule is used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment according to the intermediate variable value; The fourth calculation submodule is used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system according to the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, the voltage coefficient of the new energy equipment, the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, the aggregate equivalent inductance of each branch connected to the grid at the latest moment, the speed at the industrial frequency, the aggregate equivalent resistance of each branch connected to the grid at the latest moment, and the output voltage of the new energy station at the latest moment.

11. The device according to claim 10, characterized in that The first parameters include the collecting end current and the collecting current amplitude, the voltage amplitude and current amplitude of each branch device, the voltage phase angle and current phase angle of each branch device relative to the grid voltage, and the speed at the power frequency; The second parameters include the output voltage of the new energy station, the amplitude of the output voltage of the new energy station, the output current amplitude and output voltage amplitude of the new energy equipment, and the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage.

12. The device according to claim 11, characterized in that The first calculation submodule is specifically used to perform the following steps: For each of the four moments: Obtain the current at the collecting end and the output voltage of the new energy station collected at the moment, and calculate the phase angle of the current at the collecting end and the output voltage of the new energy station at the moment based on the current at the collecting end and the output voltage of the new energy station; Obtain the amplitude of the current at the collecting end and the amplitude of the output voltage of the new energy station collected at the moment, calculate the ratio of the amplitude of the current at the collecting end to the amplitude of the output voltage of the new energy station at the moment, and obtain the current coefficient at the moment; Obtain the voltage amplitude and current amplitude of the new energy equipment running collected at this moment, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage, and calculate the equivalent resistance and equivalent inductance of the new energy equipment at this moment based on the voltage amplitude and current amplitude of the new energy equipment running, as well as the voltage phase angle and current phase angle of the new energy equipment relative to the grid-connected voltage; Obtain the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, collected at that moment; based on the voltage amplitude and current amplitude of the mth branch device at the grid-connected point of the new energy equipment, as well as the voltage phase angle and current phase angle of the mth branch device at the grid-connected point of the new energy equipment relative to the grid-connected voltage, calculate the equivalent resistance and equivalent inductance of the mth branch device among the branch devices of the power grid system at that moment; Calculate the conductance and susceptance of the mth branch device in the branch devices of the power grid system at that moment according to the equivalent resistance and the equivalent inductance of the mth branch device in the branch devices; Based on the conductance and susceptance, calculate the equivalent resistance and equivalent inductance of m branches in the branch equipment of the power grid system at that moment after aggregation; Based on the equivalent resistance and equivalent inductance of the new energy equipment at that moment; and the equivalent resistance and equivalent inductance of m branch devices in the branch devices of the power grid system at that moment after aggregation, the aggregated equivalent resistance of each grid-connected branch and the aggregated equivalent inductance of each grid-connected branch are calculated, where m is a positive integer.

13. The device according to claim 10, characterized in that The second calculation submodule is specifically used to calculate the intermediate variable value using the following third-party program group: Among them, j1, j2, j3, and j4 are four selected moments, A j12 , B j12 , C j12 , A j34 , B j34 , C j34 is the intermediate variable; sin(α ispj1 )、sin(α ispj2 )、sin(α ispj4 )、sin(α ispj3 ) are the sine values ​​of the phase angles between the current at the sink end and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively; cos(α ispj1 )、cos(α ispj2 )、cos(α ispj3 )、cos(α ispj4 ) are the cosine values ​​of the phase angles between the sink current and the output voltage of the new energy station at time j1, time j2, time j3 and time j4 respectively; K ij2 , K ij1 , K ij4 , K ij3 They are the current coefficients of new energy equipment at time j1, time j2, time j3 and time j4 respectively; L Mj1 , L Mj2 , L Mj3 , L Mj4 are the aggregate equivalent inductance of each branch connected to the grid at time j1, time j2, time j3 and time j4 respectively; ω is the speed at the industrial frequency.

14. The device according to claim 13, characterized in that The third calculation submodule is specifically used to calculate the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station and the voltage coefficient of the new energy equipment using the following fourth equation group: α usp Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station, K v Indicates the voltage coefficient of new energy equipment.

15. The device according to claim 10, characterized in that The fourth calculation submodule is specifically used to calculate the real-time equivalent resistance, equivalent impedance and equivalent voltage of the power grid system using the following fifth set of equations: Among them, θ j Indicates the phase difference between the system equivalent voltage and the collection current at the latest moment, α uspj Indicates the phase angle between the equivalent voltage of the power grid system and the output voltage of the new energy station at the latest moment, α ispj Indicates the phase angle between the current at the sink end and the output voltage of the new energy station at the latest moment, L Mj Indicates the latest aggregate equivalent inductance of each branch connected to the grid, ω indicates the speed at the power frequency, R Mj Indicates the latest time the aggregate equivalent resistance of each branch connected to the grid, U pj Indicates the latest output voltage of the new energy station, L s Represents the real-time equivalent resistance of the power grid system, R s Indicates the real-time equivalent impedance of the power grid system, U s Indicates the real-time equivalent voltage of the power grid system.

16. The device according to claim 9, characterized in that The second calculation module is specifically used to perform the following steps: Calculating the square of the equivalent resistance of the power grid system as a first value, and calculating the product of the square of the equivalent inductance of the power grid system and the square of the rotation speed at the power frequency as a second value; Taking a square root of the sum of the first value and the second value to obtain a third value; Calculate a ratio of the third value to square root of 2 times the rated current of the new energy equipment as a fourth value; The ratio of the equivalent voltage of the power grid system to the fourth value is calculated to obtain the real-time grid-connected short-circuit ratio of the new energy equipment.

17. 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 computer program, the method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method according to any one of claims 1 to 8.

19. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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