Thermal power storage segmented commutation and segmented direct current transformation system and thermal power storage segmented commutation and segmented direct current transformation method

Abstract

The invention discloses a thermal power storage segmented commutation segmented direct current transformation system and method, and relates to the field of thermal power storage, and the method comprises the steps: generating electric energy based on a first generator and a second generator, and transmitting the electric energy to a thermal power storage segmented grid-connected unit through the outlets of the first generator and the second generator; the electric energy enters the energy storage subsection commutation conflux split boost unit through the energy storage 20kV high-voltage grid-connected A section bus and the energy storage 20kV high-voltage grid-connected B section bus; a set of energy storage current converter A and a set of energy storage current converter B of the energy storage segmented commutation confluence split boost unit adopt a power regulation control strategy to complete energy storage auxiliary frequency modulation. According to the self-adaptive droop control, the droop coefficient is adjusted according to the power adjustment deviation during frequency adjustment, so that the power is more accurately matched with the frequency adjustment quantity; the power dynamic supplement steady-state module takes an active power change rate as a compensation characteristic, is applied to PI adjustment to avoid power oscillation, and further improves the effect of energy storage auxiliary frequency modulation.

Description

Technical Field

[0001] The present invention relates to the field of thermal power energy storage, and in particular to a thermal power energy storage segmented commutation segmented DC transformation system and method. Background Art

[0002] The traditional power frequency transformer step-down model still dominates the design of auxiliary power systems for large thermal power units. Under this model, the auxiliary power system undergoes two-stage voltage transformation, stepping down from the generator output voltage of 20kV to 6kV and then further down to 400V. As unit capacity continues to increase, the capacity of the auxiliary power system has also increased dramatically. This has led to a continuous increase in the capacity of the high-voltage auxiliary transformer (HVT), significantly increasing the short-circuit current of the auxiliary power system, and placing higher demands on the short-circuit breaking capacity of the high-voltage switch.

[0003] To meet short-circuit thermal stability standards, the high-voltage cables in the power supply system must be thicker, significantly increasing investment costs. Furthermore, traditional power-frequency transformers are bulky, and expanding the power supply system often requires a capacity expansion and retrofit. This is not only costly and time-consuming, but also severely impacts the plant's normal power generation operations.

[0004] In contrast, the application of DC networking in plant power systems has shown many outstanding advantages. The DC networking has a more substantial power supply capacity, does not need to consider phase angle and frequency issues, and can realize the interconnection of asynchronous systems. Connecting plant loads to the DC plant power system through a rectifier can effectively improve the efficiency of power conversion, reduce equipment losses, realize load variable frequency drive, simplify the internal circuit of the load, and thus reduce the failure rate and equipment cost. However, despite the obvious advantages of DC networking, the actual application of the integration of thermal power energy storage and plant power systems still faces many technical challenges, such as how to achieve coordinated frequency control between energy storage systems and thermal power units and how to efficiently convert energy between different voltage levels. These problems urgently need to be solved with innovative technical solutions. Summary of the Invention

[0005] In view of the above-mentioned problem of how to achieve coordinated frequency regulation control between the energy storage system and the thermal power units in the practical application of the integration of thermal power energy storage and the plant power system, the present invention is proposed.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a thermal power energy storage segmented commutation segmented DC transformer system, which includes the following steps: A thermal power energy storage segmented grid-connected unit includes a first generator and a second generator, wherein the first generator and the second generator are respectively stepped up to 330 kV through a first main transformer and a second main transformer and connected to a 330 kV power grid system; The outlet of the first generator is connected to the A set of energy storage access switches through the energy storage 20kV high-voltage grid-connected A section bus; The outlet of the second generator is connected to the B set of energy storage access switch through the energy storage 20kV high-voltage grid-connected B section bus; The energy storage segmented commutation bus splitting and boosting unit includes an energy storage splitting and boosting transformer; the energy storage splitting and boosting transformer is connected to the energy storage 690V AC bus through a bus energy storage grid-connected switch; The energy storage 690V AC busbar is connected to the energy storage low-voltage DC circuit breaker set A and the energy storage low-voltage DC circuit breaker set B through the energy storage converter set A and the energy storage converter set B respectively; Energy storage distributed DC networking unit, including energy storage 976V DC A-section bus and energy storage 976V DC B-section bus; The energy storage 976V DC A-section bus is connected to a corresponding number of A-section energy storage modules through several groups of A-section energy storage system converter cabinets DC-DC converters; The energy storage 976V DC B-segment bus is connected to a corresponding number of B-segment energy storage modules through several groups of B-segment energy storage system converter cabinet DC-DC converters.

[0007] As a preferred solution of the thermal power energy storage segmented commutation segmented DC transformation system described in the present invention, the two branches A and B on the high-voltage side of the energy storage split step-up transformer are connected to the energy storage 20kV high-voltage grid-connected A section bus and the energy storage 20kV high-voltage grid-connected B section bus through the A set of energy storage access switches and the B set of energy storage access switches, respectively, to complete DC to AC power conversion, convergence and boosting.

[0008] As a preferred solution of the thermal power energy storage segmented commutation segmented DC transformation system described in the present invention, the energy storage 976V DC segment A bus is connected to the DC side of the A set of energy storage converters through the A set of energy storage low-voltage DC circuit breakers; The energy storage 976V DC B section bus is connected to the DC side of the B set of energy storage converters through the B set of energy storage low voltage DC circuit breakers.

[0009] Another object of the present invention is to provide a method for segmented commutation and segmented DC transformation of thermal power energy storage.

[0010] To solve the above technical problems, the present invention provides the following technical solutions: a thermal power energy storage segmented commutation and segmented DC transformation method, comprising: generating electric energy based on a first generator and a second generator, and transmitting the electric energy to a thermal power energy storage segmented grid-connected unit through the outlets of the first generator and the second generator; The electric energy enters the energy storage segmented commutation bus splitting and boosting unit through the energy storage 20kV high-voltage grid-connected section A bus and the energy storage 20kV high-voltage grid-connected section B bus; The A set of energy storage converters and the B set of energy storage converters of the energy storage segmented commutation bus splitting boost unit adopt power regulation control strategy to complete energy storage assisted frequency regulation.

[0011] As a preferred solution of the thermal power energy storage segmented commutation and segmented DC transformation method described in the present invention, the power regulation control strategy includes adopting a frequency-active power control strategy, which is expressed as: , in, is the current value of the AC side output frequency of the energy storage converter; The reference value of the AC side output frequency of the energy storage converter; is the droop control coefficient of the energy storage converter; is the initial value of the power absorbed / released on the AC side of the energy storage converter; is the current value of the power absorbed / released on the AC side of the energy storage converter; When the energy storage in section A is running, the energy storage converter set A performs power regulation. If it assists the first generator in frequency regulation, the energy storage access switch set A is closed; if it assists the second generator in frequency regulation, the energy storage access switch set B is closed. When the B section energy storage is running, the B set of energy storage converters performs power adjustment and also closes the corresponding energy storage access switch according to the different auxiliary units.

[0012] As a preferred solution of the thermal power energy storage segmented commutation and segmented DC transformation method described in the present invention, the power regulation control strategy also includes adopting an adaptive droop control scheme to increase the frequency regulation accuracy when regulating the energy storage converter, and the expression is: , in, is the droop control coefficient after frequency adjustment accuracy, is the rate of change of active power regulation; It is the active power deviation adjustment exponential coefficient.

[0013] The beneficial effects of the present invention are as follows: the adaptive droop control of the present invention adjusts the droop coefficient according to the power regulation deviation during frequency regulation, so that the power more accurately matches the frequency regulation amount; the power dynamic supplement steady-state module uses the active power change rate as the compensation feature, which is applied to PI regulation to avoid power oscillation, further improving the effect of energy storage-assisted frequency regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is a structural diagram of a thermal power energy storage segmented commutation and segmented DC transformation system provided by the first embodiment of the present invention.

[0016] In the figure: 1. Thermal power energy storage segmented grid-connected unit, 11. First generator, 12. First main transformer, 13. 330kV power grid system, 14. Energy storage 20kV high-voltage grid-connected busbar section A, 15. Energy storage access switch set A, 16. Energy storage 20kV high-voltage grid-connected busbar section B, 17. Energy storage access switch set B, 18. Second generator, 19. Second main transformer, 2. Energy storage segmented commutation, bus splitting and boosting unit, 21. Energy storage splitting and boosting transformer, 22. Bus splitting and grid-connected switch, 2 3. Energy storage converter set A, 24. Energy storage low-voltage DC circuit breaker set A, 25. Energy storage converter set B, 26. Energy storage low-voltage DC circuit breaker set B, 27. 690V AC busbar, 3. Energy storage distributed DC networking unit, 31. Energy storage 976V DC section A busbar, 32. DC-DC converter of energy storage system converter cabinet of section A, 33. Energy storage module of section A, 34. Energy storage 976V DC section B busbar, 35. DC-DC converter of energy storage system converter cabinet of section B, 36. Energy storage module of section B. DETAILED DESCRIPTION

[0017] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0018] Example 1, with reference to Figure 1 , which is an embodiment of the present invention, provides a thermal power energy storage segmented commutation segmented DC transformation system.

[0019] Preferably, the distributed energy storage module constructed by the present invention is connected to the DC network through the DC-DC converter device, and is first respectively integrated into the energy storage 976V DC A section bus 31 and the energy storage 976V DC B section bus 34, and then respectively converted into electric energy through the A set of energy storage converters 23 and the B set of energy storage converters 25; after the electric energy conversion, the two sections of the distributed energy storage module converge on the energy storage 690V AC bus 27, and the energy storage voltage is boosted from 690V to 20kV through the energy storage splitting step-up transformer 21, and connected to the energy storage 20kV high-voltage grid-connected bus; the energy storage 20kV high-voltage grid-connected bus is divided into the energy storage 20kV high-voltage grid-connected bus 14 and the energy storage 20kV high-voltage grid-connected bus 16, and are respectively connected to the outlets of the first generator 11 and the second generator 18, and combined with the thermal power unit for frequency response. The A-set energy storage converter 23 and the B-set energy storage converter 25 adopt a power regulation control strategy to reasonably allocate the power required for frequency regulation, so that the 20kV high-voltage grid-connected energy storage section A bus 14 and the 20kV high-voltage grid-connected energy storage section B bus 16 can flexibly assist the two thermal power units in frequency regulation. Among them, the 20kV high-voltage grid-connected energy storage section A bus 14 and the 20kV high-voltage grid-connected energy storage section B bus 16 can assist the two thermal power units in frequency regulation respectively, or assist one of the thermal power units in frequency regulation as a whole, or assist two thermal power units in frequency regulation at the same time. In order to increase the frequency regulation accuracy of the A-set energy storage converter 23 and the B-set energy storage converter 25 during regulation, an adaptive droop control scheme is adopted. Furthermore, a power dynamic supplement steady-state module is introduced to avoid power oscillation.

[0020] Preferably, the specific implementation method of the thermal power energy storage segmented commutation segmented DC transformation system of the present invention is: Step 1: Build the energy storage distributed DC networking unit 3. The distributed energy storage modules are networked via n DC-DC converters 32 in the energy storage system converter cabinets of segment A and n DC-DC converters 35 in the energy storage system converter cabinets of segment B. These converters 32 feed into the energy storage 976V DC segment A bus 31, while the n DC-DC converters 35 feed into the energy storage 976V DC segment B bus 34.

[0021] Among them, the DC-DC converter 32 of the energy storage system converter cabinet in section A and the DC-DC converter 35 of the energy storage system converter cabinet in section B can stabilize the DC bus voltage, providing a stable DC power supply foundation for subsequent power conversion and transmission, and at the same time realizing the initial integration and connection of the energy storage module.

[0022] Step 2: Based on the energy storage 976V DC A-segment bus 31 and the energy storage 976V DC B-segment bus 34 formed in step 1, build the energy storage segmented commutation bus splitting and boosting unit 2.

[0023] Among them, in the energy storage segmented commutation bus splitting boost unit 2, the energy storage 976V DC A segment bus 31 is connected to the DC side of the A set of energy storage converter 23 through the A set of energy storage low-voltage DC circuit breaker 24; the energy storage 976V DC B segment bus 34 is connected to the DC side of the B set of energy storage converter 25 through the B set of energy storage low-voltage DC circuit breaker 26.

[0024] At the same time, an energy storage split step-up transformer 21 is used, and its low-voltage side is connected to the energy storage 690V AC bus 27 through the energy storage grid-connected switch 22, and the energy storage 690V AC bus 27 is connected to the AC side of the A set energy storage converter 23 and the B set energy storage converter 25 respectively.

[0025] The A and B branches on the high-voltage side of the energy storage split step-up transformer 21 are connected to the energy storage 20kV high-voltage grid-connected A section bus 14 and the energy storage 20kV high-voltage grid-connected B section bus 16 through the A set of energy storage access switch 15 and the B set of energy storage access switch 17 respectively.

[0026] The second step realizes the conversion, convergence and voltage boosting of DC to AC power, laying the foundation for the connection between the energy storage module and the thermal power unit.

[0027] Step 3: Set up the thermal power energy storage segmented grid-connected unit 1. Based on the energy storage distributed DC networking unit 3 and the energy storage segmented commutation, bus, splitting, and boosting unit 2 established in the previous two steps, set up the thermal power energy storage segmented grid-connected unit 1. Step up the thermal power generator from 20kV to 330kV through the main transformer and connect it to the 330kV grid system 13.

[0028] At the outlets of the first generator 11 and the second generator 18 (i.e., the low-voltage side of the main transformer), the energy storage 20kV high-voltage grid-connected section A bus 14 and the energy storage 20kV high-voltage grid-connected section B bus 16 are respectively arranged to enable the energy storage module to establish an electrical connection with the thermal power units, creating conditions for joint frequency regulation.

[0029] Step 4: Achieve energy storage-assisted frequency regulation. Based on the completed thermal power energy storage segmented commutation and segmented DC transformer system, energy storage-assisted frequency regulation is achieved using the power regulation control strategy adopted in the energy storage converter set A 23 and the energy storage converter set B 25.

[0030] When the A section energy storage module is running, the A set energy storage converter 23 performs power regulation. If it assists the first generator 11 in frequency regulation, the A set energy storage access switch 15 is closed; if it assists the second generator 18 in frequency regulation, the B set energy storage access switch 17 is closed.

[0031] When the B-section energy storage module is running, the B-set energy storage converter 25 performs power regulation and similarly closes the corresponding energy storage access switch according to the different auxiliary units.

[0032] In this way, the A and B sections of energy storage modules can flexibly assist the two thermal power units in frequency regulation. The A and B sections of energy storage modules can assist the two units separately, assist one of the units as a whole, or assist both units in frequency regulation at the same time.

[0033] In step 5, based on the energy storage-assisted frequency regulation achieved in step 4, an adaptive droop control scheme is adopted to increase the frequency regulation accuracy when regulating the energy storage converter set A 23 and the energy storage converter set B 25 .

[0034] In step 6, based on step 5, a power dynamic supplement steady-state module is further introduced to avoid power oscillation.

[0035] It should be noted that in the energy storage distributed DC networking unit 3, n segment A energy storage modules 33 are connected to the energy storage 976V DC segment A bus 31 via the segment A energy storage system converter cabinet DC-DC converter 32, and n segment B energy storage modules 36 are connected to the energy storage 976V DC segment B bus 34 via the segment B energy storage system converter cabinet DC-DC converter 35. This corresponds to step 1. Here, n is an arbitrary number greater than or equal to 2.

[0036] Preferably, this embodiment demonstrates a specific method of distributed energy storage DC networking. The DC-DC converter 32 of the energy storage system converter cabinet in section A and the DC-DC converter 35 of the energy storage system converter cabinet in section B ensure the stability of the DC bus voltage, realize the initial integration and connection of the energy storage module, and provide a stable DC power supply foundation for subsequent power conversion and transmission.

[0037] Reference Figure 1 In the energy storage segmented commutation bus splitting and boosting unit 2, the energy storage 976V DC A segment bus 31 formed based on the first step is connected to the A set energy storage converter 23 through the AC side of the A set energy storage low-voltage DC circuit breaker 24; the energy storage 976V DC B segment bus 34 formed based on the first step is connected to the B set energy storage converter 25 through the AC side of the B set energy storage low-voltage DC circuit breaker 26.

[0038] Meanwhile, the energy storage 976V DC A-section busbar 31 and the energy storage 976V DC B-section busbar 34 are connected to the AC sides of the energy storage converters A and B, respectively. They are also connected to the low-voltage side of the energy storage split-step-up transformer 21 via the energy storage grid-connected switch 22. The A and B branches of the high-voltage side of the energy storage split-step-up transformer 21 are connected to the energy storage 20kV high-voltage grid-connected A-section busbar 14 and the energy storage 20kV high-voltage grid-connected B-section busbar 16 via the energy storage access switch 15 and the energy storage access switch 17, respectively. This demonstrates the process of converting DC to AC, converging, and boosting electrical energy, and is a key architecture for connecting energy storage to thermal power units.

[0039] Reference Figure 1 In the thermal power and energy storage segmented grid-connected unit 1, the first generator 11 and the second generator 18 are stepped up from 20kV to 330kV via the first main transformer 12 and the second main transformer 19, respectively, and then connected to the 330kV power system 13. At the outlets of the first and second generators 11 and 18 (on the low-voltage side of the main transformer), a 20kV high-voltage grid-connected busbar A for energy storage and a 20kV high-voltage grid-connected busbar B for energy storage are located. This section establishes the electrical connection between the energy storage and the thermal power units, creating conditions for joint frequency regulation.

[0040] Combined with step 4, from Figure 1 As can be seen from the overall connection relationship, when the system requires energy storage-assisted frequency regulation, the corresponding energy storage converter (set A energy storage converter 23 or set B energy storage converter 25) is used for power regulation depending on the energy storage operating segment (segment A or segment B). By closing or opening the set A energy storage access switch 15 and the set B energy storage access switch 17, the two-segment energy storage module can flexibly assist the frequency regulation of the first generator 11 and the second generator 18, assisting the frequency regulation of the units individually, collectively, or simultaneously.

[0041] According to steps 5 and 6, Figure 1 Based on the presented system architecture, the energy storage converter optimizes performance by adopting an adaptive droop control scheme and introducing a power dynamic supplement steady-state module.

[0042] Adaptive droop control adjusts the droop coefficient according to the power regulation deviation during frequency regulation, so that the power more accurately matches the frequency regulation amount.

[0043] The power dynamic supplement steady-state module uses the frequency-active power change rate as the compensation feature and applies it to PI regulation to avoid power oscillation and further improve the effect of energy storage-assisted frequency regulation.

[0044] Example 2, which is an embodiment of the present invention, provides a thermal power energy storage segmented commutation segmented DC transformation method, including: generating electric energy based on a first generator 11 and a second generator 18, and transmitting the electric energy to a thermal power energy storage segmented grid-connected unit 1 through the outlets of the first generator 11 and the second generator 18; The electric energy enters the energy storage segmented commutation bus splitting and boosting unit 2 through the energy storage 20kV high voltage grid-connected A section bus 14 and the energy storage 20kV high voltage grid-connected B section bus 16; The energy storage converter set A 23 and the energy storage converter set B 25 of the energy storage segmented commutation bus splitting boost unit 2 adopt the frequency-active power control strategy to complete the energy storage assisted frequency regulation, and the expression is: (1) in, is the current value of the AC side output frequency of the energy storage converter; The reference value of the AC side output frequency of the energy storage converter; is the droop control coefficient of the energy storage converter; is the initial value of the power absorbed / released on the AC side of the energy storage converter; It is the current value of the power absorbed / released on the AC side of the energy storage converter.

[0045] In order to increase the frequency regulation accuracy during energy storage converter regulation, an adaptive droop control scheme is adopted to increase the frequency regulation accuracy during energy storage converter regulation. The expression is: (2) in, is the droop control coefficient after frequency adjustment accuracy, is the droop control coefficient of the energy storage converter, is the rate of change of active power regulation; The active power deviation adjustment exponential coefficient is used to adaptively adjust the droop coefficient according to the power adjustment deviation during frequency adjustment. This can increase the frequency adjustment accuracy and make the video power more accurately match the frequency adjustment amount.

[0046] Furthermore, a power dynamic compensation steady-state module is introduced to avoid power oscillation. The numerical expression to be compensated is: (3) in, is the power value to be compensated, Dynamically supplement the steady-state proportional coefficient for power; is the power dynamic supplement steady-state integral coefficient; s is the Laplace operator; is the active power change rate.

[0047] Applying PI regulation to the power dynamic compensation steady-state module can effectively avoid power oscillations caused by frequency regulation. Using the active power change rate as the compensation characteristic can effectively reflect the amount of power change.

[0048] Introducing formula (3) and formula (2) into formula (1), we can get: (4) in, is the current value of the AC side output frequency of the energy storage converter; The reference value of the AC side output frequency of the energy storage converter; is the vertical control coefficient after frequency adjustment accuracy; is the initial value of the power absorbed / released on the AC side of the energy storage converter; is the current value of the power absorbed / released by the AC side of the energy storage converter, is the power value to be compensated.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. 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 thermal power energy storage segmented commutation segmented DC transformation system, characterized in that: include: A thermal power energy storage segmented grid-connected unit (1) comprises a first generator (11) and a second generator (18), wherein the first generator (11) and the second generator (18) are respectively boosted to 330 kV via a first main transformer (12) and a second main transformer (19) and connected to a 330 kV power grid system (13); The outlet of the first generator (11) is connected to the A-set energy storage access switch (15) via the energy storage 20kV high-voltage grid-connected A-section busbar (14); The outlet of the second generator (18) is connected to the B set of energy storage access switch (17) via the energy storage 20kV high-voltage grid-connected B section bus (16); The energy storage segmented commutation bus splitting and boosting unit (2) comprises an energy storage splitting and boosting transformer (21); the energy storage splitting and boosting transformer (21) is connected to the energy storage 690V AC bus (27) via a bus energy storage grid-connected switch (22); The energy storage 690V AC busbar (27) is connected to the energy storage low-voltage DC circuit breaker (24) and the energy storage low-voltage DC circuit breaker (26) of set A through the energy storage converter (23) and the energy storage converter (25) of set B respectively; An energy storage distributed DC networking unit (3), comprising an energy storage 976V DC section A bus (31) and an energy storage 976V DC section B bus (34); The energy storage 976V DC A-section busbar (31) is connected to a corresponding number of A-section energy storage modules (33) through a plurality of groups of A-section energy storage system converter cabinet DC-DC converters (32); The energy storage 976V DC B-segment busbar (34) is connected to a corresponding number of B-segment energy storage modules (36) via a plurality of groups of B-segment energy storage system converter cabinet DC-DC converters (35).

2. The thermal power energy storage segmented commutation segmented DC transformation system according to claim 1, characterized in that: The two branches A and B on the high-voltage side of the energy storage split step-up transformer (21) are connected to the energy storage 20kV high-voltage grid-connected A section bus (14) and the energy storage 20kV high-voltage grid-connected B section bus (16) through the A set of energy storage access switches (15) and the B set of energy storage access switches (17), respectively, to complete the DC to AC power conversion, convergence and boosting.

3. The thermal power energy storage segmented commutation segmented DC transformation system according to claim 2, characterized in that: The energy storage 976V DC section A busbar (31) is connected to the DC side of the A set of energy storage converters (23) via the A set of energy storage low-voltage DC circuit breakers (24); The energy storage 976V DC B segment busbar (34) is connected to the DC side of the B set of energy storage converter (25) via the B set of energy storage low voltage DC circuit breaker (26).

4. A thermal power energy storage segmented commutation and segmented DC transformation method, using a thermal power energy storage segmented commutation and segmented DC transformation system according to any one of claims 1 to 3, characterized in that: Generate electric energy based on the first generator (11) and the second generator (18), and transmit the electric energy to the thermal power energy storage segmented grid-connected unit (1) through the outlets of the first generator (11) and the second generator (18); The electric energy enters the energy storage segmented commutation bus splitting and boosting unit (2) through the energy storage 20kV high voltage grid-connected section A bus (14) and the energy storage 20kV high voltage grid-connected section B bus (16); The A-set energy storage converter (23) and the B-set energy storage converter (25) of the energy storage segmented commutation bus splitting boost unit (2) adopt a power regulation control strategy to complete energy storage-assisted frequency regulation.

5. A thermal power energy storage segmented commutation and segmented DC transformation method according to claim 4, characterized in that: The power regulation control strategy includes adopting a frequency-active power control strategy, which is expressed as: ， in, is the current value of the AC side output frequency of the energy storage converter; The reference value of the AC side output frequency of the energy storage converter; is the droop control coefficient of the energy storage converter; is the initial value of the power absorbed / released on the AC side of the energy storage converter; is the current value of the power absorbed / released on the AC side of the energy storage converter; When the A section energy storage is running, the A set energy storage converter (23) performs power regulation. If it assists the first generator (11) in frequency regulation, the A set energy storage access switch (15) is closed; if it assists the second generator (18) in frequency regulation, the B set energy storage access switch (17) is closed. When the B section energy storage is in operation, the B set energy storage converter (25) performs power regulation and similarly closes the corresponding energy storage access switch according to the difference in the auxiliary units.

6. A thermal power energy storage segmented commutation and segmented DC transformation method according to claim 5, characterized in that: The power regulation control strategy also includes adopting an adaptive droop control scheme to increase the frequency regulation accuracy when regulating the energy storage converter. The expression is: ， in, is the droop control coefficient after frequency adjustment accuracy, is the rate of change of active power regulation; It is the active power deviation adjustment exponential coefficient.

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