Thermal power energy storage distributed boost segmented grid-connected system and method

Abstract

The invention discloses a thermal power energy storage distributed boost subsection grid-connected system and method, and relates to the technical field of thermal power energy storage, and the system is characterized in that an A set of energy storage DC networking unit and a B set of energy storage DC networking unit are connected to a low-voltage side A section and a low-voltage side B section of a low-voltage energy storage boost transformer through a current conversion device, the voltage is boosted from 690V to 6kV through low-voltage energy storage boost, and confluence energy storage passes through a high-voltage split winding transformer; the low-voltage side of the high-voltage split winding transformer is 6kV, and the voltage level of the high-voltage side is 20kV; a high-voltage side is divided into a section A and a section B which are respectively connected to an alternating-current 20kV energy storage section A and an alternating-current 20kV energy storage section B, and the alternating-current 20kV energy storage section A and the alternating-current 20kV energy storage section B are respectively connected to outlets of a first generator and a second generator and are combined with a thermal power generating unit to carry out frequency adjustment. According to the method, a segmented commutation concentrated boosting and re-segmented boosting mode is adopted, the control mode is flexible, and compared with a concentrated boosting distributed power supply scheme of a distributed generator of a modern electric power system, two-segment energy storage can flexibly assist in frequency adjustment of two thermal power generating units.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power energy storage, and in particular to a thermal power energy storage distributed boosting segmented grid-connected system and method. Background Art

[0002] At present, the typical design of the power supply system of large thermal power units is to tap the step-down transformer at the generator outlet, which can be divided into two-stage transformers. The first stage is to step down the 20kV at the generator outlet to 6kV, and the second stage is to step down the 6kV to 400V. Both use industrial frequency transformers and involve AC power. With the continuous increase in the capacity of the unit, the capacity of the power supply system is also increasing. The capacity of the high-voltage power supply transformer is getting larger, and the short-circuit current of the power supply system is very large, which puts higher requirements on the short-circuit breaking capacity of the high-voltage switch. In order to meet the requirements of short-circuit thermal stability, the high-voltage cable of the power supply system needs to choose thicker cables, which increases the investment cost. Traditional high-voltage power supply transformers use industrial frequency transformers, which are huge in size, and in order to obtain a larger capacity of the power supply system, they are often remodeled for capacity expansion. The cost of the transformation is huge, the construction period is long, and the normal power generation of the power plant is delayed.

[0003] The use of DC networking in the power supply system can effectively solve some bottleneck problems in the development of traditional AC power supply systems. Compared with the traditional AC power supply system, DC networking has many advantages: DC networking has a larger power supply capacity; DC networking does not need to consider phase angle and frequency, and can realize asynchronous system interconnection. The power supply load is connected to the DC power supply system through the rectifier, which can improve the efficiency of power conversion and reduce equipment loss, realize load variable frequency drive, simplify the internal circuit of the load, and reduce the failure rate and equipment cost. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is that as the capacity of the unit continues to increase, the capacity of the plant power system is also increasing, the capacity of the high-voltage plant transformer becomes larger, the short-circuit current of the plant power system is very large, and higher requirements are put forward on the short-circuit breaking capacity of the high-voltage switch. In order to meet the requirements of short-circuit thermal stability, the high-voltage cable of the plant power system needs to select thicker cables, which increases the investment cost.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a thermal power energy storage distributed boosting segmented grid-connected system, comprising a thermal power energy storage segmented grid-connected unit, an energy storage segmented commutation transformer splitting boosting unit and an energy storage segmented DC main grid unit; the first generator and the second generator in the thermal power energy storage segmented grid-connected unit are respectively boosted to 330kV by the first main transformer and the second main transformer, and connected to the 330kV power grid system, and the outlets of the first generator and the second generator are respectively connected to the AC 20kV energy storage A segment bus and AC 20kV energy storage B section bus; the energy storage segmented conversion transformer splitting boost unit includes a high-voltage energy storage boost transformer, a low-voltage energy storage boost transformer, a low-voltage segmented A set of energy storage commutation devices and a low-voltage segmented B set of energy storage commutation devices; the AC 20kV energy storage A section bus and the AC 20kV energy storage B section bus are connected to the high-voltage energy storage boost transformer; an A section bus switch is provided between the high-voltage energy storage boost transformer and the AC 20kV energy storage A section bus, and the A section bus switch is used to control the AC 20 kV energy storage A section bus and the high voltage energy storage step-up transformer are disconnected; a B section bus switch is provided between the low voltage energy storage step-up transformer and the AC 20kV energy storage B section bus, and the B section bus switch is used to control the disconnection between the AC 20kV energy storage B section bus and the low voltage energy storage step-up transformer; the energy storage segmented DC main grid unit includes a segment A DC energy storage networking unit and a segment B DC energy storage networking unit, which are connected in the form of DC networking; the segment A DC energy storage networking unit includes a 976V energy storage A The 976V energy storage segment A is connected to the segment A energy storage system converter cabinet, and the segment A energy storage module is connected to the segment A energy storage system converter cabinet through a DC-DC converter device; the segment B DC energy storage networking unit includes a 976V energy storage segment B, a segment B energy storage system converter cabinet and a segment B energy storage module; the 976V energy storage segment B is connected to the segment B energy storage system converter cabinet, and the segment B energy storage system converter cabinet is connected to the segment B energy storage module through a DC-DC converter device.

[0007] As a preferred solution of the thermal power energy storage distributed boost segmented grid-connected system described in the present invention, wherein: the low-voltage segmented A set of energy storage commutation devices and the low-voltage segmented B set of energy storage commutation devices will centrally invert the electric energy converged by the AC 20kV energy storage A segment bus and the AC 20kV energy storage B segment bus, and the low-voltage segmented A set of energy storage commutation devices and the low-voltage segmented B set of energy storage commutation devices adopt a droop control scheme containing a compensation module; the high-voltage side of the high-voltage energy storage boosting transformer adopts a split winding scheme; the low-voltage side of the low-voltage energy storage boosting transformer adopts a split winding scheme.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: A method for a thermal power energy storage distributed boost segmented grid-connected system, which includes: a segment A DC energy storage networking unit and a segment B DC energy storage networking unit are connected to the low-voltage side A and B segments of the low-voltage energy storage boost transformer through their own low-voltage segment A set of energy storage commutation devices and low-voltage segment B set of energy storage commutation devices, and the voltage is boosted from 690V to 6kV through a low-voltage energy storage boost transformer, and the energy storage is merged through a high-voltage energy storage boost transformer; the high-voltage energy storage boost transformer The low voltage side is 6kV, and the high voltage side adopts split winding with a voltage level of 20kV; the high voltage side of the high voltage energy storage step-up transformer is divided into two sections, A and B, which are respectively connected to the AC 20kV energy storage section A and the AC 20kV energy storage section B. The AC 20kV energy storage sections A and B are respectively connected to the outlets of the first generator and the second generator, and the thermal power units are combined for frequency regulation; in the low voltage segmented A set of energy storage commutation devices and the low voltage segmented B set of energy storage commutation devices, a droop control compensation scheme containing a compensation module is adopted.

[0009] As a preferred solution of the method of the thermal power energy storage distributed boost segmented grid-connected system described in the present invention, wherein: the droop control compensation scheme using a compensation module includes adopting a resistive droop control scheme in the A and B sets of energy storage commutation devices, establishing voltage-active power and frequency-reactive power droop control equations expressed as, , in, Output voltage amplitude for energy storage commutation device; Output voltage reference value for energy storage commutation device; is the voltage-active power droop coefficient of the energy storage commutation device; Output / absorb active power for energy storage commutation device; Output the current value of the frequency to the energy storage commutation device; Output frequency reference value for energy storage commutation device; is the frequency-reactive power droop coefficient of the energy storage commutation device; Output / absorb reactive power for energy storage inverter.

[0010] As a preferred solution of the method of a thermal power energy storage distributed boost segmented grid-connected system described in the present invention, the droop control compensation scheme using a compensation module also includes introducing an active and reactive power fluctuation PI control supplementary module to suppress the fluctuation. The mathematical expression of the active and reactive power fluctuation PI control supplementary module is: , Among them, k pE k is the proportional phase in the active power fluctuation PI regulation, iE k is the integral phase in the active power fluctuation PI regulation; pɷis the proportional phase in reactive power fluctuation PI regulation, k iɷ is the integral phase in reactive power fluctuation PI regulation; s is the Laplace factor; Output voltage regulation value for energy storage commutation device; Output frequency adjustment value for the energy storage inverter.

[0011] As a preferred solution of the method of the thermal power energy storage distributed boost segmented grid-connected system described in the present invention, the droop control compensation scheme using the compensation module also includes introducing the active and reactive power fluctuation PI control supplementary module into the voltage-active power and frequency-reactive power droop control equations, and suppressing the active and reactive power fluctuations during voltage and frequency regulation. , in, The output voltage amplitude of the energy storage converter after active power fluctuation suppression is: It is the current value of the output frequency of the energy storage converter after the reactive power fluctuation is suppressed.

[0012] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned thermal power energy storage distributed boosting and segmented grid-connected system and method are implemented.

[0013] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a thermal power energy storage distributed boosting and segmented grid-connected system and method as described above.

[0014] The beneficial effects of the present invention are as follows: in the energy storage segmented commutation transformer split boost unit 2, the present invention adopts segmented commutation centralized boosting and then segmented boosting, and the control method is flexible, which is analogous to the centralized boosting and distributed power supply scheme of the modern power system distributed generator, and can realize two-stage energy storage to flexibly assist the frequency regulation of two thermal power units.

[0015] The present invention adopts a droop control scheme containing a compensation module in the A and B sets of energy storage converters to reduce the transient fluctuations of active and reactive power during frequency and voltage regulation. Specifically, voltage-active power and frequency-reactive power droop control equations are constructed, and active and reactive power fluctuation PI control supplementary modules are introduced to suppress the fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 This is a structural diagram of a thermal power energy storage distributed boost segmented grid-connected system in Example 1.

[0018] In the figure: 1. Thermal power energy storage segmented grid-connected unit; 2. Energy storage segmented commutation transformer splitting and boosting unit; 3. Energy storage segmented DC main grid unit; 11. First generator; 12. First main transformer; 13. 30kV power grid system; 14. AC 20kV energy storage section A bus; 15. Section A bus switch; 16. AC 20kV energy storage section B bus; 17. Section B bus switch; 18. Second generator; 19. Second main transformer; 21. High-voltage energy storage boosting transformer; 22. Boosting switch; 23. Low-voltage storage 1. Energy step-up transformer; 24. Low-voltage segment A set of energy storage conversion device; 25. Low-voltage segment B set of energy storage conversion device; 31. DC 976V energy storage segment A; 32. A segment energy storage system converter cabinet 1; 33. A segment #1 energy storage module; 34. A segment energy storage system converter cabinet n; 35. A segment #n energy storage module; 36. DC 976V energy storage segment B; 37. B segment energy storage system converter cabinet 1; 38. B segment #1 energy storage module; 39. B segment energy storage system converter cabinet m; 310. B segment #n energy storage module. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] Example 1 Reference Figure 1 , which is the first embodiment of the present invention, and which provides a thermal power energy storage distributed boost segmented grid-connected system including: Figure 1 As shown: The system includes a thermal power energy storage segmented grid-connected unit 1; an energy storage segmented commutation transformation splitting and boosting unit 2; and an energy storage segmented DC main grid unit 3.

[0022] Among them, the first generator 11 and the second generator 18 in the thermal power energy storage segmented grid-connected unit 1 are respectively stepped up to 330 kV through the first main transformer 12 and the second main transformer 19, and connected to the 330 kV power grid system 13, and the outlets of the first generator 11 and the second generator 18 are respectively connected to the AC 20 kV energy storage A section bus 14 and the AC 20 kV energy storage B section bus 16.

[0023] The energy storage segmented commutation transformer splitting boost unit 2 comprises a high voltage energy storage boost transformer 21, a low voltage energy storage boost transformer 23, a low voltage segmented A set of energy storage commutation devices 24 and a low voltage segmented B set of energy storage commutation devices 25.

[0024] The AC 20 kV energy storage A section bus 14 and the AC 20 kV energy storage B section bus 16 are connected to the high-voltage energy storage step-up transformer 21 .

[0025] A section bus switch 15 is provided between the high-voltage energy storage boosting transformer 21 and the AC 20kV energy storage section A bus 14 . The section A bus switch 15 is used to control the disconnection between the AC 20kV energy storage section A bus 14 and the high-voltage energy storage boosting transformer 21 .

[0026] A section B bus switch 17 is provided between the low-voltage energy storage boosting transformer 23 and the AC 20 kV energy storage section B bus 16 . The section B bus switch 17 is used to control the disconnection between the AC 20 kV energy storage section B bus 16 and the low-voltage energy storage boosting transformer 23 .

[0027] The energy storage segmented DC main grid unit 3 includes a segment A DC energy storage networking unit and a segment B DC energy storage networking unit, which are connected in the form of DC networking.

[0028] The A-section DC energy storage networking unit includes the 976V energy storage A-section, the A-section energy storage system converter cabinet and the A-section energy storage module; the 976V energy storage A-section is connected to the A-section energy storage system converter cabinet, and the A-section energy storage system converter cabinet is connected to the A-section energy storage module through a DC-DC converter device.

[0029] The B-section DC energy storage networking unit includes the 976V energy storage B-section, the B-section energy storage system converter cabinet and the B-section energy storage module; the 976V energy storage B-section is connected to the B-section energy storage system converter cabinet, and the B-section energy storage system converter cabinet is connected to the B-section energy storage module through a DC-DC converter device.

[0030] The low voltage segment A set of energy storage inverter devices 24 and the low voltage segment B set of energy storage inverter devices 25 centrally invert the electric energy converged through the AC 20kV energy storage A section bus 14 and the AC 20kV energy storage B section bus 16, and the low voltage segment A set of energy storage inverter devices 24 and the low voltage segment B set of energy storage inverter devices 25 adopt a droop control scheme containing a compensation module.

[0031] The high voltage side of the high voltage energy storage boost transformer 21 adopts a split winding solution; the low voltage side of the low voltage energy storage boost transformer 23 adopts a split winding solution.

[0032] A further improvement of the present invention is that the energy storage is connected to the generator outlet of the thermal power unit through two-stage voltage boosting through commutation, which is more efficient for the unit frequency response, and is in parallel with the thermal power unit. As a stable voltage source, energy storage provides more services such as black start, voltage stabilization, and stable power for the power system. Furthermore, the voltage changes from DC 976V to AC 690V to AC 6kV to AC 20kV. In the AC 6kV section, the original equipment of the thermal power unit can be connected, which can be used as a backup power supply for the high-voltage plant 6kV section, improving the power supply reliability of the unit plant system.

[0033] The further improvement of the present invention is that in the energy storage segmented conversion transformer split boost unit 2, segmented conversion centralized boosting and then segmented boosting are adopted, and the control mode is flexible, which is similar to the centralized boosting and distributed power supply scheme of the modern power system distributed generator, and can realize the two-stage energy storage to flexibly assist the frequency regulation of two thermal power units. When the A-stage energy storage assists the first generator in frequency regulation, the A-set energy storage conversion device performs power control, the B-set energy storage conversion device is in a locked disconnected state, and the AC 20kV energy storage A-stage grid-connected switch is closed; when the A-stage energy storage assists the second generator 18 in frequency regulation, the A-set energy storage conversion device performs power control, the B-set energy storage conversion device is in a locked disconnected state, and the AC 20kV energy storage B-stage bus switch is closed. (Similarly, write that the B-stage energy storage assists the first generator 11 and the second generator 18 in frequency regulation).

[0034] A further improvement of the present invention is that a droop control scheme containing a compensation module is adopted in the A and B sets of energy storage converters to reduce the transient fluctuations of active and reactive power when the frequency and voltage are adjusted. The specific structure is the voltage-active power and frequency-reactive power droop control equations, and the active and reactive power fluctuation PI control supplementary module is introduced to suppress the fluctuations.

[0035] Example 2 This is the second embodiment of the present invention, which is different from the first embodiment in that: a method for a thermal power energy storage distributed boost segmented grid-connected system includes: a section A DC energy storage networking unit and a section B DC energy storage networking unit are connected to the low-voltage side A and B sections of the low-voltage energy storage boost transformer through their own low-voltage segment A set of energy storage conversion devices and low-voltage segment B set of energy storage conversion devices, and the voltage is boosted from 690V to 6kV through a low-voltage energy storage boost transformer, and the energy storage is merged through a high-voltage energy storage boost transformer.

[0036] The low-voltage side of the high-voltage energy storage step-up transformer is 6kV, and the high-voltage side adopts split winding with a voltage level of 20kV.

[0037] The high-voltage side of the high-voltage energy storage step-up transformer is divided into two sections, A and B, which are connected to the AC 20kV energy storage section A and the AC 20kV energy storage section B respectively. The AC 20kV energy storage sections A and B are connected to the outlets of the first generator and the second generator respectively, and the frequency is adjusted in conjunction with the thermal power units.

[0038] In the low-voltage segment A set of energy storage commutation devices and the low-voltage segment B set of energy storage commutation devices, a droop control compensation scheme containing a compensation module is adopted.

[0039] The droop control compensation scheme including the compensation module includes adopting a resistive droop control scheme in the A and B energy storage commutation devices, and establishing voltage-active power and frequency-reactive power droop control equations expressed as: , in, Output voltage amplitude for energy storage commutation device; Output voltage reference value for energy storage commutation device; is the voltage-active power droop coefficient of the energy storage commutation device; Output / absorb active power for energy storage commutation device; Output the current value of the frequency to the energy storage commutation device; Output frequency reference value for energy storage commutation device; is the frequency-reactive power droop coefficient of the energy storage commutation device; Output / absorb reactive power for energy storage inverter.

[0040] The active and reactive power fluctuation PI control supplementary module is introduced to suppress the fluctuation. The mathematical expression of the active and reactive power fluctuation PI control supplementary module is: , Among them, k pE k is the proportional phase in the active power fluctuation PI regulation, iE k is the integral phase in the active power fluctuation PI regulation; pɷ is the proportional phase in reactive power fluctuation PI regulation, k iɷ is the integral phase in reactive power fluctuation PI regulation; s is the Laplace factor; Output voltage regulation value for energy storage commutation device; Output frequency adjustment value for the energy storage inverter.

[0041] The active and reactive power fluctuation PI control supplementary module is introduced into the voltage-active power and frequency-reactive power droop control equations to suppress the active and reactive power fluctuations during voltage and frequency regulation. , in, The output voltage amplitude of the energy storage converter after active power fluctuation suppression is: It is the current value of the output frequency of the energy storage converter after the reactive power fluctuation is suppressed.

[0042] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0043] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0044] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0045] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A distributed boosting and segmented grid-connected system for thermal power energy storage, characterized in that: include, A thermal power energy storage segmented grid-connected unit (1), an energy storage segmented commutation transformer splitting and boosting unit (2), and an energy storage segmented DC main grid unit (3); The first generator (11) and the second generator (18) in the thermal power energy storage segmented grid-connected unit (1) are respectively stepped up to 330 kV via the first main transformer (12) and the second main transformer (19), and connected to the 330 kV power grid system (13); the outlets of the first generator (11) and the second generator (18) are respectively connected to the AC 20 kV energy storage segment A busbar (14) and the AC 20 kV energy storage segment B busbar (16); The energy storage segmented commutation transformer splitting boost unit (2) comprises a high-voltage energy storage boost transformer (21), a low-voltage energy storage boost transformer (23), a low-voltage segmented A set of energy storage commutation devices (24) and a low-voltage segmented B set of energy storage commutation devices (25); The AC 20 kV energy storage A section busbar (14) and the AC 20 kV energy storage B section busbar (16) are connected to the high-voltage energy storage step-up transformer (21); A section bus switch (15) is provided between the high-voltage energy storage boosting transformer (21) and the AC 20 kV energy storage section A bus (14), and the section A bus switch (15) is used to control the opening and closing between the AC 20 kV energy storage section A bus (14) and the high-voltage energy storage boosting transformer (21); A section B bus switch (17) is provided between the low-voltage energy storage boosting transformer (23) and the AC 20 kV energy storage section B bus (16), and the section B bus switch (17) is used to control the opening and closing between the AC 20 kV energy storage section B bus (16) and the low-voltage energy storage boosting transformer (23); The energy storage segmented DC main grid unit (3) comprises a segment A DC energy storage networking unit and a segment B DC energy storage networking unit, which are connected in a DC networking form; The A-section DC energy storage networking unit includes a 976V energy storage A-section, an A-section energy storage system converter cabinet and an A-section energy storage module; the 976V energy storage A-section is connected to the A-section energy storage system converter cabinet, and the A-section energy storage system converter cabinet is connected to the A-section energy storage module through a DC-DC converter device; The B-section DC energy storage networking unit includes a 976V energy storage B-section, a B-section energy storage system converter cabinet and a B-section energy storage module; the 976V energy storage B-section is connected to the B-section energy storage system converter cabinet, and the B-section energy storage system converter cabinet is connected to the B-section energy storage module through a DC-DC converter device.

2. A thermal power energy storage distributed boost segmented grid-connected system as claimed in claim 1, characterized in that: The low-voltage segment A set of energy storage commutation devices (24) and the low-voltage segment B set of energy storage commutation devices (25) centrally invert the electric energy converged through the AC 20 kV energy storage A segment busbar (14) and the AC 20 kV energy storage B segment busbar (16), and the low-voltage segment A set of energy storage commutation devices (24) and the low-voltage segment B set of energy storage commutation devices (25) adopt a droop control scheme containing a compensation module; The high-voltage side of the high-voltage energy storage step-up transformer (21) adopts a split winding solution; The low-voltage side of the low-voltage energy storage step-up transformer (23) adopts a split winding solution.

3. A method of using a thermal power energy storage distributed boost segmented grid-connected system as claimed in any one of claims 1 to 2, characterized in that: include, The DC energy storage networking unit of section A and the DC energy storage networking unit of section B are connected to the low-voltage side A and B sections of the low-voltage energy storage step-up transformer through their respective low-voltage segment A set of energy storage commutation devices and low-voltage segment B set of energy storage commutation devices, and are stepped up by the low-voltage energy storage step-up transformer from 690V to 6kV, and the energy storage is combined and passed through the high-voltage energy storage step-up transformer; The low voltage side of the high voltage energy storage step-up transformer is 6kV, and the high voltage side uses split windings with a voltage level of 20kV; The high-voltage side of the high-voltage energy storage step-up transformer is divided into two sections, A and B, which are connected to the AC 20kV energy storage section A and the AC 20kV energy storage section B respectively. The AC 20kV energy storage sections A and B are connected to the outlets of the first generator and the second generator respectively, and the thermal power unit is combined for frequency regulation; In the low-voltage segment A set of energy storage commutation devices and the low-voltage segment B set of energy storage commutation devices, a droop control compensation scheme containing a compensation module is adopted.

4. A method for a thermal power energy storage distributed boosting and segmented grid-connected system as claimed in claim 3, characterized in that: The droop control compensation scheme using the compensation module includes adopting a resistive droop control scheme in the A and B energy storage commutation devices, establishing voltage-active power and frequency-reactive power droop control equations expressed as: ， in, Output voltage amplitude for energy storage commutation device; Output voltage reference value for energy storage commutation device; is the voltage-active power droop coefficient of the energy storage commutation device; Output / absorb active power for energy storage commutation device; Output the current value of the frequency to the energy storage commutation device; Output frequency reference value for energy storage commutation device; is the frequency-reactive power droop coefficient of the energy storage commutation device; Output / absorb reactive power for energy storage inverter.

5. A method for a thermal power energy storage distributed boosting and segmented grid-connected system as claimed in claim 4, characterized in that: The droop control compensation scheme using the compensation module also includes introducing an active and reactive power fluctuation PI control supplementary module to suppress the fluctuation. The mathematical expression of the active and reactive power fluctuation PI control supplementary module is: ， Among them, k pE k is the proportional phase in the active power fluctuation PI regulation, iE k is the integral phase in the active power fluctuation PI regulation; pɷ k is the proportional phase in reactive power fluctuation PI regulation, iɷ is the integral phase in reactive power fluctuation PI regulation; s is the Laplace factor; Output voltage regulation value for energy storage commutation device; Output frequency adjustment value for the energy storage inverter.

6. A method for a thermal power energy storage distributed boosting and segmented grid-connected system as claimed in claim 5, characterized in that: The droop control compensation scheme using the compensation module also includes introducing the active and reactive power fluctuation PI control supplementary module into the voltage-active power and frequency-reactive power droop control equations to suppress the active and reactive power fluctuations during voltage and frequency regulation. ， in, The output voltage amplitude of the energy storage converter after active power fluctuation suppression is: It is the current value of the output frequency of the energy storage converter after the reactive power fluctuation is suppressed.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for a thermal power energy storage distributed boost segmented grid-connected system according to any one of claims 3 to 6 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for a thermal power energy storage distributed boost segmented grid-connected system according to any one of claims 3 to 6 are implemented.

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