Network construction type converter proportion configuration method and system suitable for hundred percent new energy independent power supply system

Abstract

The invention provides a network construction type converter proportion configuration method and system suitable for a hundred percent new energy independent power supply system. The method comprises the following steps: carrying out information sampling before configuration of a network construction type converter of the hundred percent new energy independent power supply system; according to the number of the sampled network construction converters and the internal impedance of the network construction converters, performing network construction type new energy field station internal impedance equivalence to obtain the network construction type new energy field station internal impedance; calculating the short-circuit ratio of the low-voltage side of the step-up transformer of the following network type new energy station, comparing the calculated short-circuit ratio with a critical short-circuit ratio SCR0, and setting the short-circuit ratio of the low-voltage side of the step-up transformer of the following network type new energy station not to be less than the critical short-circuit ratio SCR0 according to the stable operation requirement of the system; and calculating to obtain the proportion configuration of the networking converter in the hundred percent new energy independent power supply system. According to the invention, an effective basis can be provided for the proportion configuration of the networking converter in the hundred-percent new energy independent power supply system, and the safe and stable operation capability of the hundred-percent new energy independent operation system is improved.

Description

Technical Field

[0001] The present invention relates to the field of operation control technology for a new energy power generation system, and specifically to a method and system for configuring the proportion of a grid-connected converter suitable for a 100% new energy independent power supply system. Background Art

[0002] With the rapid development of new energy power generation and control technology, high-proportion new energy represented by wind and light is gradually connected to the power system. The wide access of high-proportion new energy and the large-scale application of high-proportion power electronic equipment are becoming important trends and key features of the development of power systems. At present, most new energy converters in power systems adopt grid-following control. Through the input of active power or voltage, the input current is controlled for adjustment, and then the active / reactive power fed into the power grid is controlled. At the same time, it must rely on the phase-locked loop to synchronize with the power grid, showing the characteristics of current source, lacking the ability to actively support the power grid and inertia response. Many studies have been carried out on the single-machine operation characteristics of grid-building converters, evaluating the inertia characteristics of photovoltaic and wind turbines under grid-building control, and believing that they have good support capabilities for the voltage / frequency of the power grid, but there are few stability analyses under high-proportion or even 100% grid-building / grid-following hybrid systems. From the perspective of power grid operation, some countries in the world, such as Denmark and Ireland, have experienced scenarios where the instantaneous penetration rate of new energy has reached or even exceeded 100% during some periods of the year. The system stability operation problem in this extreme scenario is essentially different from the AC power grid dominated by high-proportion synchronous machines.

[0003] Photovoltaic power generation and wind power generation have limited frequency and reactive power support capabilities for the power grid under the traditional current source control mode, and it is difficult to meet the stable operation requirements of a 100% renewable energy independent power grid. For a 100% renewable energy independent power grid, a certain proportion of grid-forming control units must be added to form a grid-forming / grid-following hybrid system. The addition of grid-forming control units can enhance the stability of the system on certain time scales, improve the system's support capabilities, and enhance the strength of the power grid. However, too few grid-forming units are not enough to support the entire independent operation system, and too many grid-forming units may cause oscillation problems with a wider frequency band. At the same time, the mechanical and electrical systems of the grid-forming wind turbines are electromechanically coupled, forming a new electromechanical coupling oscillation risk, which may cause serious equipment damage.

[0004] Therefore, there is an urgent need to provide a method and system for configuring the proportion of grid-connected converters suitable for a 100% renewable energy independent power supply system, which can provide an effective basis for the minimum proportion configuration of grid-connected converters in a 100% renewable energy independent power supply system, and is of great significance for improving the safe and stable operation of a 100% renewable energy independent operation system. Summary of the invention

[0005] To solve the above problems, the present invention provides a method and system for configuring the proportion of grid-connecting converters suitable for a 100% new energy independent power supply system, which can provide an effective basis for the proportional configuration of grid-connecting converters in the 100% new energy independent power supply system, effectively avoid the situation where the grid-connecting converters are configured too much or too little, and improve the safe and stable operation capability of the 100% new energy independent operation system.

[0006] To achieve the above purpose, the first embodiment of the present invention provides a method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system, comprising the following steps:

[0007] Step S1: Conducting information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting the system topology, collecting the boost transformer leakage reactance of the grid-type new energy station, collecting the internal impedance of the grid-type converter, collecting the number of grid-type converters, and collecting the boost transformer leakage reactance of the grid-type new energy station;

[0008] Step S2: define the proportion of grid-connected converters in the 100% new energy system g , New energy short circuit ratio SCR e , according to the number of grid-forming converters sampled in step S1 and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station;

[0009] S3: According to the system topology structure collected in step S1, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-following new energy station and the internal impedance of the grid-forming new energy station obtained in step S2, calculate the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station, compare the calculated short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station with the critical short-circuit ratio SCR0, set the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station to be not less than the critical short-circuit ratio SCR0 according to the requirements for stable operation of the system, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

[0010] Furthermore, in step S2, the proportion of grid-type converters s is defined by the following formula: g :

[0011]

[0012] Among them, s g is the proportion of grid-connected converters, S gfm , S gfl They are the installed capacities of grid-building converter and grid-following converter respectively.

[0013] Further, in step S2, the new energy short circuit ratio SCR of the 100% new energy independent power supply system is defined by the following formula: e, used to measure the relative strength of the AC system constructed by the grid-forming converter and the grid-following new energy:

[0014]

[0015] Among them, SCR e is the short-circuit ratio of new energy, S ac is the system short-circuit capacity, P N For the rated capacity of grid-following renewable energy, Z pu is the per unit value of the system impedance.

[0016] Further, in step S2, the internal impedance of the grid-forming new energy station is equalized according to the number of grid-forming converters and the internal impedance of the grid-forming converter sampled in step 1 to obtain the internal impedance of the grid-forming new energy station, which specifically includes:

[0017] According to the number of grid-connected converters N and the internal impedance Z of the grid-connected converter gfm Conduct impedance calculations for network-based new energy stations:

[0018]

[0019] Z gfm_c Represents the internal impedance of a grid-connected new energy station.

[0020] Further, in step S3, according to the system topology structure collected in step 1, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-forming new energy station, and the internal impedance of the grid-forming new energy station obtained in step 2, the short-circuit ratio of the boost transformer low-voltage side of the grid-forming new energy station is calculated, which specifically includes:

[0021] According to the system topology structure acquired in step S1, the per unit value of the system impedance on the step-up to low-voltage side of the grid-connected new energy station is calculated as follows:

[0022]

[0023] According to the calculation formula of the new energy short-circuit ratio defined in step S2, the short-circuit ratio of the boost-to-low-voltage side of the grid-connected new energy station is calculated:

[0024]

[0025] Among them, Z gfm_c represents the internal impedance of the grid-type new energy station, Z T1 To build a grid-type new energy station boost transformer leakage resistor, s g is the proportion of grid-connected converters, Z T2 To boost the leakage resistance of grid-connected new energy stations.

[0026] Further, in step S3, the calculated short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station is compared with the critical short-circuit ratio SCR0, and the short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station is set to be not less than the critical short-circuit ratio SCR0 according to the system stable operation requirements, and the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system is calculated, specifically including:

[0027] According to the requirements of stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station is set to be no less than the critical short-circuit ratio SCR0, that is:

[0028]

[0029] According to the above formula, it is calculated that the proportional configuration of the grid-connected converter in the 100% renewable energy independent power supply system must satisfy the following formula:

[0030]

[0031] A grid-type converter ratio configuration system applicable to a 100% renewable energy independent power supply system, comprising:

[0032] The first processor is used to carry out information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting system topology, collecting grid-type new energy station boost transformer leakage reactance, collecting grid-type converter internal impedance, collecting grid-type converter quantity, and collecting grid-type new energy station boost transformer leakage reactance;

[0033] The second processor is used to define the proportion of grid-connected converters in the 100% new energy system. g , New energy short circuit ratio SCR e , according to the number of sampled grid-forming converters and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station;

[0034] The third processor is used to calculate the short-circuit ratio of the boost transformer side of the grid-type new energy station according to the collected system topology, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-forming new energy station and the obtained internal impedance of the grid-forming new energy station, compare the calculated short-circuit ratio of the boost transformer side of the grid-forming new energy station with the critical short-circuit ratio SCR0, set the short-circuit ratio of the boost transformer side of the grid-forming new energy station to be not less than the critical short-circuit ratio SCR0 according to the requirement of stable operation of the system, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

[0035] Further, the third processor calculates the short-circuit ratio of the boost transformer low-voltage side of the grid-type new energy station according to the collected system topology, the boost transformer leakage reactance of the grid-type new energy station, the boost transformer leakage reactance of the grid-type new energy station, and the obtained internal impedance of the grid-type new energy station, specifically including:

[0036] According to the collected system topology, the per unit value of the system impedance on the boost-to-low voltage side of the grid-connected new energy station is calculated as follows:

[0037]

[0038] According to the defined calculation formula of new energy short-circuit ratio, the short-circuit ratio of the boost-to-low-voltage side of the grid-connected new energy station is calculated:

[0039]

[0040] Among them, Z gfm_c represents the internal impedance of the grid-type new energy station, Z T1 To build a grid-type new energy station boost transformer leakage resistor, s g is the proportion of grid-connected converters, Z T2 To boost the leakage resistance of grid-connected new energy stations.

[0041] Further, the third processor compares the calculated short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station with the critical short-circuit ratio SCR0, and sets the short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station to be not less than the critical short-circuit ratio SCR0 according to the system stable operation requirements, and calculates the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system, specifically including:

[0042] According to the requirements of stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station is set to be no less than the critical short-circuit ratio SCR0, that is:

[0043]

[0044] According to the above formula, it is calculated that the proportional configuration of the grid-connected converter in the 100% renewable energy independent power supply system must satisfy the following formula:

[0045]

[0046] In order to solve the problem of unclear configuration ratio of grid-type converters in the stable operation of a 100% new energy independent power supply system, the present invention provides a method for configuring the proportion of grid-type converters based on short-circuit ratio, which can avoid the problem of system oscillation caused by over-configuration of grid-type converters while ensuring the stable operation of the independent power supply system. It effectively solves the problem of configuration ratio of grid-type converters in a 100% new energy independent power supply system and provides an effective basis for the configuration of grid-type converters in independent power supply systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the topological structure of a 100% renewable energy independent power supply system according to an embodiment of the present invention;

[0049] Figure 3 This is a root locus analysis diagram of a 100% renewable energy independent power supply system according to an embodiment of the present invention;

[0050] Figure 4 It is the time domain waveform result after configuration of a grid-connecting converter ratio configuration method applicable to a 100% new energy independent power supply system in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention clearer and easier to understand, the present invention will be further described in detail in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 Embodiment 1 of the present invention provides a method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system, the method comprising the following steps:

[0053] Step S1: Carry out information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting the system topology, collecting the grid-type new energy station boost transformer leakage reactance, collecting the grid-type converter internal impedance, collecting the number of grid-type converters, and collecting the grid-type new energy station boost transformer leakage reactance.

[0054] Acquisition system topology, Figure 2 As an example, the topology of a 100% renewable energy independent power supply system is obtained; the grid-type renewable energy station boost transformer leakage resistor Z is collected T1 , the internal impedance Z of the grid-type convertergfm ,Number of grid-connected converters,N,Grid-connected new energy station boost transformer leakage resistor Z T2 .

[0055] Step S2: define the proportion of grid-connected converters in the 100% new energy system g , New energy short circuit ratio SCR e According to the number of grid-forming converters sampled in step S1 and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station.

[0056] Specifically, the proportion of grid-type converters s is defined as follows: g :

[0057]

[0058] Among them, s g is the proportion of grid-connected converters, S gfm , S gfl They are the installed capacities of grid-building converter and grid-following converter respectively.

[0059] Define the new energy short circuit ratio SCR of 100% new energy independent power supply system by the following formula e , used to measure the relative strength of the AC system constructed by the grid-forming converter and the grid-following new energy:

[0060]

[0061] Among them, SCR e is the short-circuit ratio of new energy, S ac is the system short-circuit capacity, P N For the rated capacity of grid-following renewable energy, Z pu is the per unit value of the system impedance.

[0062] According to the number of grid-connected converters N and the internal impedance Z of the grid-connected converter gfm Conduct impedance calculations for network-based new energy stations:

[0063]

[0064] Z gfm_c Represents the internal impedance of a grid-connected new energy station.

[0065] S3: According to the system topology structure collected in step S1, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-following new energy station and the internal impedance of the grid-forming new energy station obtained in step S2, calculate the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station, compare the calculated short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station with the critical short-circuit ratio SCR0, and according to the requirements for stable system operation, set the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station to be no less than the critical short-circuit ratio SCR0, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

[0066] Specifically, according to the system topology structure acquired in step S1, the per unit value of the system impedance of the boost-to-low-voltage side of the grid-type new energy station under the system topology structure is calculated to be

[0067]

[0068] According to the calculation formula of the new energy short-circuit ratio defined in step S2, the short-circuit ratio of the boost-to-low-voltage side of the grid-connected new energy station is calculated:

[0069]

[0070] Among them, Z gfm_c represents the internal impedance of the grid-type new energy station, Z T1 To build a grid-type new energy station boost transformer leakage resistor, s g is the proportion of grid-connected converters, Z T2 To boost the leakage resistance of grid-connected new energy stations.

[0071] According to the requirements of stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station is set to be no less than the critical short-circuit ratio SCR0, that is:

[0072]

[0073] According to the above formula, it can be calculated that the proportional configuration of grid-connected converters in a 100% renewable energy independent power supply system must satisfy the following formula:

[0074]

[0075] In a specific embodiment, build in MATLAB / Smulink Figure 2 The 100% renewable energy independent power supply system shown in the figure, according to an embodiment of the present invention, provides a method for configuring the proportion of grid-connected converters suitable for the 100% renewable energy independent power supply system, in which the critical short-circuit ratio SCR0 is set to 1.5 and N is 3. According to formula (6), it can be calculated that the proportion of grid-connected converters is not less than 30%.

[0076] Figure 3This is the root locus analysis diagram of the 100% renewable energy independent power supply system. The black dotted line with an arrow indicates the direction of movement of the characteristic root, and the black dot indicates the characteristic root. As the proportion of the grid-connected converter changes from large to small, the characteristic root moves in the direction of the dotted arrow. When the proportion of the grid-connected converter is less than 30%, the characteristic root with the largest real part appears in the right half plane. According to the properties of the characteristic root, the system is no longer stably operating at this time.

[0077] Figure 4 This is the time domain waveform result after the proposed method is configured. At this time, the proportion of grid-connected converters is 33%, which is slightly larger than the result calculated according to formula (6). The system operates stably.

[0078] pass Figure 3 and Figure 4 The analysis results show that the system can operate stably by configuring the grid-connected converter according to the results calculated by the proposed method.

[0079] Embodiment 2 of the present invention provides a grid-connected converter ratio configuration system applicable to a 100% renewable energy independent power supply system, including:

[0080] The first processor is used to carry out information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting system topology, collecting grid-type new energy station boost transformer leakage reactance, collecting grid-type converter internal impedance, collecting grid-type converter quantity, and collecting grid-type new energy station boost transformer leakage reactance;

[0081] The second processor is used to define the proportion of grid-connected converters in the 100% new energy system. g , New energy short circuit ratio SCR e , according to the number of sampled grid-forming converters and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station;

[0082] The third processor is used to calculate the short-circuit ratio of the boost transformer side of the grid-type new energy station according to the collected system topology, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-forming new energy station and the obtained internal impedance of the grid-forming new energy station, compare the calculated short-circuit ratio of the boost transformer side of the grid-forming new energy station with the critical short-circuit ratio SCR0, set the short-circuit ratio of the boost transformer side of the grid-forming new energy station to be not less than the critical short-circuit ratio SCR0 according to the requirement of stable operation of the system, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

[0083] Compared with the prior art, the grid-connected converter ratio configuration method and system provided by the embodiment of the present invention, which is applicable to a 100% renewable energy independent power supply system, has the following beneficial effects:

[0084] In order to solve the problem of unclear configuration ratio of grid-type converters in the stable operation of 100% new energy independent power supply system, a grid-type converter ratio configuration method based on short-circuit ratio is provided, which can avoid the problem of system oscillation caused by over-configuration of grid-type converters while ensuring the stable operation of the independent power supply system. It effectively solves the problem of configuration ratio of grid-type converters in 100% new energy independent power supply system and provides an effective basis for the configuration of grid-type converters in independent power supply system.

[0085] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system, characterized in that: The following steps are involved: Step S1: Conducting information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting the system topology, collecting the boost transformer leakage reactance of the grid-type new energy station, collecting the internal impedance of the grid-type converter, collecting the number of grid-type converters, and collecting the boost transformer leakage reactance of the grid-type new energy station; Step S2: define the proportion of grid-connected converters in the 100% new energy system g , New energy short circuit ratio SCR e , according to the number of grid-forming converters sampled in step S1 and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station; S3: According to the system topology structure collected in step S1, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-following new energy station and the internal impedance of the grid-forming new energy station obtained in step S2, calculate the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station, compare the calculated short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station with the critical short-circuit ratio SCR0, set the short-circuit ratio of the boost transformer low voltage side of the grid-following new energy station to be not less than the critical short-circuit ratio SCR0 according to the requirements for stable operation of the system, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

2. The method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to claim 1, characterized in that: In step S2, the proportion of grid-type converters s is defined by the following formula: g : Among them, s g is the proportion of grid-connected converters, S gfm , S gfl They are the installed capacities of grid-building converter and grid-following converter respectively.

3. The method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to claim 1, characterized in that: In step S2, the new energy short circuit ratio SCR of the 100% new energy independent power supply system is defined by the following formula: e , used to measure the relative strength of the AC system constructed by the grid-forming converter and the grid-following new energy: Among them, SCR e is the short-circuit ratio of new energy, S ac is the system short-circuit capacity, P N is the rated capacity of grid-following renewable energy, Z pu is the per unit value of the system impedance.

4. The method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to claim 3, characterized in that: In step S2, the internal impedance of the grid-forming new energy station is equalized according to the number of grid-forming converters and the internal impedance of the grid-forming converter sampled in step S1 to obtain the internal impedance of the grid-forming new energy station, which specifically includes: According to the number of grid-connected converters N and the internal impedance Z of the grid-connected converter gfm Conduct impedance calculations for network-based new energy stations: Z gfm_c Represents the internal impedance of a grid-connected new energy station.

5. The method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to claim 4, characterized in that: Step S3 calculates the short-circuit ratio of the boost transformer low-voltage side of the grid-type new energy station according to the system topology structure collected in step S1, the boost transformer leakage reactance of the grid-type new energy station, the boost transformer leakage reactance of the grid-type new energy station, and the internal impedance of the grid-type new energy station obtained in step 2, specifically including: According to the system topology structure acquired in step S1, the per unit value of the system impedance on the step-up to low-voltage side of the grid-connected new energy station is calculated as follows: According to the calculation formula of the new energy short-circuit ratio defined in step S2, the short-circuit ratio of the boost-to-low-voltage side of the grid-connected new energy station is calculated: Among them, Z gfm_c represents the internal impedance of the grid-type new energy station, Z T1 To build a grid-type new energy station boost transformer leakage resistor, s g is the proportion of grid-connected converters, Z T2 To boost the leakage resistance of grid-connected new energy stations.

6. The method for configuring the proportion of grid-connected converters applicable to a 100% renewable energy independent power supply system according to claim 5, characterized in that: In step S3, the calculated short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station is compared with the critical short-circuit ratio SCR0. According to the requirements for stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-type new energy station is set to be not less than the critical short-circuit ratio SCR0, and the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system is calculated, specifically including: According to the requirements of stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station is set to be no less than the critical short-circuit ratio SCR0, that is: According to the above formula, it is calculated that the proportional configuration of the grid-connected converter in the 100% renewable energy independent power supply system must satisfy the following formula:

7. A grid-type converter ratio configuration system suitable for a 100% renewable energy independent power supply system, characterized in that: include: The first processor is used to carry out information sampling before configuring the grid-type converter of the 100% new energy independent power supply system, including collecting system topology, collecting grid-type new energy station boost transformer leakage reactance, collecting grid-type converter internal impedance, collecting grid-type converter quantity, and collecting grid-type new energy station boost transformer leakage reactance; The second processor is used to define the proportion of grid-connected converters in the 100% new energy system. g , New energy short circuit ratio SCR e , according to the number of sampled grid-forming converters and the internal impedance of the grid-forming converter, the internal impedance of the grid-forming new energy station is equalized to obtain the internal impedance of the grid-forming new energy station; The third processor is used to calculate the short-circuit ratio of the boost transformer side of the grid-type new energy station according to the collected system topology, the boost transformer leakage reactance of the grid-forming new energy station, the boost transformer leakage reactance of the grid-forming new energy station and the obtained internal impedance of the grid-forming new energy station, compare the calculated short-circuit ratio of the boost transformer side of the grid-forming new energy station with the critical short-circuit ratio SCR0, set the short-circuit ratio of the boost transformer side of the grid-forming new energy station to be not less than the critical short-circuit ratio SCR0 according to the requirement of stable operation of the system, and calculate the proportional configuration of the grid-forming converter in the 100% new energy independent power supply system.

8. The grid-connected converter ratio configuration system applicable to a 100% renewable energy independent power supply system as described in claim 7, characterized in that: The third processor calculates the short-circuit ratio of the boost transformer low-voltage side of the grid-type new energy station according to the collected system topology, the boost transformer leakage reactance of the grid-type new energy station, the boost transformer leakage reactance of the grid-type new energy station, and the obtained internal impedance of the grid-type new energy station, specifically including: According to the collected system topology, the per unit value of the system impedance on the boost-to-low voltage side of the grid-connected new energy station is calculated as follows: According to the defined calculation formula of new energy short-circuit ratio, calculate the short-circuit ratio of the boost-to-low-voltage side of the grid-connected new energy station: Among them, Z gfm_c represents the internal impedance of the grid-type new energy station, Z T1 To build a grid-type new energy station boost transformer leakage resistor, s g is the proportion of grid-connected converters, Z T2 To boost the leakage resistance of grid-connected new energy stations.

9. The grid-connected converter ratio configuration system applicable to a 100% renewable energy independent power supply system as described in claim 8, characterized in that: The third processor compares the calculated short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station with the critical short-circuit ratio SCR0, sets the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station to be not less than the critical short-circuit ratio SCR0 according to the system stable operation requirements, and calculates the proportional configuration of the grid-building converter in the 100% new energy independent power supply system, specifically including: According to the requirements of stable operation of the system, the short-circuit ratio of the boost-to-low-voltage side of the grid-following new energy station is set to be no less than the critical short-circuit ratio SCR0, that is: According to the above formula, it is calculated that the proportional configuration of the grid-connected converter in the 100% renewable energy independent power supply system must satisfy the following formula:

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