Thermal power energy storage high-voltage access system and method

Abstract

The invention discloses a thermal power storage high-voltage access system and method, and relates to the field of thermal power storage, and the method comprises the steps: generating electric energy through a first power generator and a second power generator, and transmitting the electric energy to a thermal power storage distributed access unit through the outlets of the first power generator and the second power generator; electric energy enters the energy storage distributed commutation boost unit through the 22kV energy storage bus of the A section and the B section; a set of energy storage flexible current converter A and a set of energy storage flexible current converter B of the energy storage distributed current conversion boosting unit adopt a direct current virtual synchronous machine control scheme, and the response performance of energy storage to frequency regulation is optimized. A direct-current virtual synchronous machine control scheme is adopted in an A set of energy storage flexible current converter and a B set of energy storage flexible current converter, a direct-current virtual synchronous machine rotor mechanical equation is constructed according to the steady-state active variable quantity and the dynamic power fluctuation quantity, and in order to reduce the power overshoot when energy storage responds to a thermal power generating unit frequency modulation instruction, the direct-current virtual synchronous machine rotor mechanical equation is constructed. A self-adaptive virtual damping control scheme is adopted, and a direct-current virtual synchronous machine control scheme containing self-adaptive virtual damping is constructed.

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 high-voltage access system and method. Background Art

[0002] Currently, the typical design for the auxiliary power system of large thermal power units utilizes a two-stage transformer with a tapped step-down transformer at the generator output. The first stage steps down the generator output voltage from 20kV to 6kV, and the second stage steps it down again from 6kV to 400V. Both stages utilize power-frequency transformers and operate on AC power. As unit capacity continues to increase, the capacity of auxiliary power systems also increases, leading to larger high-voltage transformers and significantly higher short-circuit currents in auxiliary power systems. This places higher demands on the short-circuit breaking capacity of high-voltage switchgear, necessitating thicker high-voltage cables for auxiliary power systems to meet short-circuit thermal stability requirements, thereby increasing investment costs. Traditional high-voltage auxiliary power transformers utilize power-frequency transformers, which are bulky. To achieve greater auxiliary power system capacity, these transformers often require capacity expansion and renovation, which is costly and time-consuming, disrupting normal power generation at the power plant.

[0003] Adopting a DC network in the utility power system effectively addresses some bottlenecks in the development of traditional AC utility power systems. Compared to traditional AC utility power systems, DC networking offers numerous advantages: It offers greater power capacity; it eliminates the need to consider phase angle and frequency, enabling interconnection of asynchronous systems; and connecting utility loads to the DC utility power system through rectifiers improves power conversion efficiency and reduces equipment losses. This enables variable-frequency drive of loads, simplifies internal load circuitry, and reduces both failure rates and equipment costs. Summary of the Invention

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

[0005] Therefore, the technical problem solved by the present invention is: how to achieve dynamic power coordination between thermal power units and distributed energy storage modules, improve frequency regulation accuracy and system redundancy and fault tolerance, while suppressing high-voltage DC bus voltage fluctuations.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a thermal power energy storage high voltage access system, which includes the following steps: A thermal power energy storage distributed access 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 energy storage access switch via the A-section 22kV energy storage busbar; The outlet of the second generator is connected to the B set of energy storage access switch through the B section 22kV energy storage busbar; The energy storage distributed commutation and boosting unit includes a set of energy storage boosting transformers A and a set of energy storage boosting transformers B, wherein the set of energy storage boosting transformers A is connected to the set of energy storage DC circuit breaker A through the set of energy storage flexible converter A, and the set of energy storage boosting transformers B is connected to the set of energy storage DC circuit breaker B through the set of energy storage flexible converter B; A distributed energy storage DC networking unit includes a DC 975V energy storage bus, a plurality of DC-DC converter units connected to the DC 975V energy storage bus, and an energy storage module connected to the DC-DC converter units.

[0007] As a preferred solution of the thermal power energy storage high-voltage access system described in the present invention, the energy storage boosting transformer set A and the energy storage boosting transformer set B are respectively connected to the energy storage access switch set A and the energy storage access switch set B in the thermal power energy storage distributed access unit, so that the energy storage boosting transformer set A interacts with the first generator, and the energy storage boosting transformer set B interacts with the second generator.

[0008] As a preferred solution of the thermal power energy storage high-voltage access system described in the present invention, the distributed energy storage DC networking unit connects a plurality of energy storage modules to a DC network through corresponding DC-DC converter units, and converges them into a DC 975V energy storage bus; One end of the DC 975V energy storage busbar is connected to the DC side of the energy storage flexible converter set A through the energy storage DC circuit breaker set A, and the end of the DC 975V energy storage busbar away from the energy storage DC circuit breaker set A is connected to the DC side of the energy storage flexible converter set B through the energy storage DC circuit breaker set B; A DC virtual synchronous machine control scheme is adopted in set A of energy storage flexible converters and set B of energy storage flexible converters to optimize the response performance of energy storage to frequency regulation.

[0009] Another object of the present invention is to provide a method for high-voltage access to thermal power energy storage.

[0010] To solve the above technical problems, the present invention provides the following technical solutions: a method for high-voltage access to thermal power energy storage, comprising: generating electric energy by a first generator and a second generator, and transmitting the electric energy to a thermal power energy storage distributed access unit through the outlets of the first generator and the second generator; Electric energy enters the energy storage distributed commutation and boosting unit through the 22kV energy storage busbar in section A and the 22kV energy storage busbar in section B; The A-set flexible energy storage converter and the B-set flexible energy storage converter of the distributed energy storage commutation and boosting unit adopt a DC virtual synchronous machine control scheme to optimize the response performance of energy storage to frequency regulation.

[0011] As a preferred solution of the high-voltage access method for thermal power energy storage described in the present invention, the DC virtual synchronous machine control solution constructs a DC virtual synchronous machine rotor mechanical equation based on the steady-state active power change and dynamic power fluctuation, and uses droop control and virtual rotor inertia to determine the power regulation amount. The expression is: , in, is the damping coefficient, is the current value of the AC side output frequency of the energy storage flexible converter, is the target value of the AC side output frequency of the energy storage flexible converter; is the instantaneous active power absorbed or emitted by the virtual rotor inertia, is the virtual moment of inertia; The derivative of the current value output frequency is the frequency change; is the active output of the DC side of the energy storage flexible converter when DC droop control is adopted. is the DC voltage droop coefficient; is the current value of the voltage on the DC side of the energy storage flexible converter; is the initial voltage value of the DC side of the energy storage flexible converter; is the charging and discharging power of the DC side filter capacitor of the energy storage flexible converter, is the DC side filter capacitor value, It is the derivative of the current DC side voltage of the energy storage flexible converter, and the result is the voltage change rate.

[0012] As a preferred solution of the high-voltage access method for thermal power energy storage described in the present invention, the DC virtual synchronous machine control solution includes an adaptive virtual damping control solution based on the use of droop control and virtual rotor inertia to determine the power regulation amount. During the frequency increase phase, the virtual damping is adaptively reduced to reduce the power to the target value; during the angular frequency reduction phase, the virtual damping is adaptively increased to suppress power oscillations. The expression is: , in, is the output value of the adaptive virtual damping control scheme, is the frequency change, is the initial virtual damping; is the adaptive virtual damping adjustment coefficient; The meaning is or; By introducing the damping into the mechanical equation of the DC virtual synchronous machine rotor, the mechanical equation of the DC virtual synchronous machine rotor with the ability to suppress power oscillation is obtained, which is expressed as: , in, is the output value of the adaptive virtual damping control scheme.

[0013] The beneficial effects of the present invention are as follows: the present invention adopts a segmented power regulation strategy, which can accurately match the output fluctuations of thermal power units with changes in load demand, and reduce bus voltage oscillations caused by power mutations; by dynamically allocating the charging and discharging power of the energy storage unit and coordinating the timing of the commutation module, it optimizes the energy storage utilization rate, extends the equipment life, avoids the single point failure risk of traditional centralized commutation, and enhances system redundancy and operational reliability; the modular segmented design can flexibly expand the commutation capacity and reduce the system upgrade cost. 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 high-voltage access system provided by the first embodiment of the present invention.

[0016] Figure 1: 1. Thermal power energy storage distributed access unit, 11. First generator, 12. First main transformer, 13. 330kV grid system, 14. Section A 22kV energy storage busbar, 15. Set A energy storage access switch, 16. Set B energy storage access switch, 17. Section B 22kV energy storage busbar, 18. Second generator, 19. Second main transformer, 2. Energy storage distributed commutation and boosting unit, 21. Set A energy storage boosting transformer, 22. Set A energy storage flexible converter, 23. Set A energy storage DC circuit breaker, 24. Set B energy storage boosting transformer, 25. Set B energy storage flexible converter, 26. Set B energy storage DC circuit breaker, 3. Distributed energy storage DC networking unit, 31. DC 975V energy storage busbar, 32. DC-DC commutation unit, 33. Energy storage module. 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, but 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, reference Figure 1 , as an embodiment of the present invention, provides a thermal power energy storage high-voltage access system.

[0019] Preferably, the present invention constructs a two-stage DC power system for thermal power plants, wherein the distributed energy storage module 33 is connected to a DC 975V energy storage bus 31 through a plurality of DC-DC converter units 32 .

[0020] The DC 975V energy storage bus 31 is connected to two sets of flexible converters, specifically a set A of energy storage flexible converters 22 and a set B of energy storage flexible converters 25 .

[0021] The AC side of the A-set energy storage flexible converter 22 is connected to the low-voltage side of the A-set energy storage step-up transformer 21 .

[0022] The AC side of the B-set energy storage flexible converter 25 is connected to the low-voltage side of the B-set energy storage boost transformer 24 .

[0023] The high voltage side of the A-set energy storage step-up transformer 21 is connected to the outlet of the first generator 11 through the A-section 22 kV energy storage bus 14 .

[0024] The high voltage side of the B set energy storage step-up transformer 24 is connected to the outlet of the second generator 18 through the B section 22kV energy storage bus 17.

[0025] The energy storage module 33 can assist the frequency regulation of the first generator 11 and the second generator 18, two thermal power generating units.

[0026] Furthermore, in order to enable the energy storage module 33 to better respond to the frequency regulation instructions of the thermal power unit, a DC virtual synchronous machine control scheme is adopted in the set A energy storage flexible converter 22 and the set B energy storage flexible converter 25, so that the energy storage module 33 has better performance in responding to the frequency regulation process.

[0027] In order to achieve the above object, the present invention adopts the following specific technical solutions: The thermal power energy storage high-voltage access system includes a thermal power energy storage distributed access unit 1, an energy storage distributed commutation and boosting unit 2, and a distributed energy storage DC networking unit 3.

[0028] Among them, in the thermal power energy storage distributed access unit 1, the A section 22kV energy storage bus 14 is used to access the outlet of the first generator 11; the B section 22kV energy storage bus 17 is used to access the outlet of the second generator 18.

[0029] By providing the A set energy storage access switch 15 and the B set energy storage access switch 16 , the access or disconnection operation of the A set energy storage module and the B set energy storage module is realized respectively.

[0030] It should be further explained that the distributed energy storage DC networking unit 3 comprises n sets of energy storage modules 33, which are connected to a 975V DC energy storage bus 31 through corresponding DC-DC converter units 32. This DC networking is simple and efficient, where n is a natural integer greater than or equal to 2. Furthermore, the distributed energy storage DC networking unit 3 can be autonomously divided into set A and set B energy storage modules, respectively assisting in frequency regulation of the first generator 11 and the second generator 18.

[0031] When the energy storage module A assists the first generator 11 in frequency regulation, the energy storage access switch 15 (energy storage high-voltage GCB switch (Generator Circuit-Breaker)) of set A is closed, while the energy storage access switch 16 (energy storage high-voltage GCB switch) of set B is opened.

[0032] When the B energy storage module assists the second generator 18 in frequency regulation, the B energy storage access switch 16 (energy storage high-voltage GCB switch) is closed, and the A energy storage access switch 15 (energy storage high-voltage GCB switch) is opened.

[0033] The energy storage distributed commutation and boosting unit 2 is divided into a set A of energy storage boosting transformers 21 and a set B of energy storage boosting transformers 24 .

[0034] The A-set energy storage boost transformer 21 controls the A-set energy storage flexible converter 22 to enable the energy storage module 33 to perform power regulation control according to the frequency instruction.

[0035] The B-set energy storage boost transformer 24 controls the B-set energy storage flexible converter 25 to enable the energy storage module 33 to perform power regulation control according to the frequency instruction.

[0036] The DC side of the A-set energy storage flexible converter 22 is connected to the A-set energy storage DC circuit breaker 23 .

[0037] The DC side of the B-set energy storage flexible converter 25 is connected to the B-set energy storage DC circuit breaker 26 .

[0038] Compared with AC circuit breakers, DC circuit breakers have simpler protection and on-off logic.

[0039] The DC virtual synchronous machine control scheme is adopted in the A set of energy storage flexible converters 22 and the B set of energy storage flexible converters 25, so that the energy storage module 33 has better performance in the response frequency adjustment process.

[0040] The distributed energy storage DC networking unit 3 has n sets of energy storage modules 33, which are converged into the DC 975V energy storage bus 31 through correspondingly connected DC-DC converter units 32. The DC networking is simple and efficient, where n is a natural integer and is greater than or equal to 2.

[0041] Furthermore, in order to realize the frequency regulation of the first generator 11 and the second generator 18 by the energy storage module 33, the energy storage distributed commutation and boosting unit 2 is used to accurately configure the energy storage charging / discharging power according to the frequency regulation instruction.

[0042] An A-set energy storage access switch 15 is configured on the high-voltage side of the A-set energy storage step-up transformer 21 .

[0043] A set B energy storage access switch 16 is configured on the high voltage side of the set B energy storage step-up transformer 24 .

[0044] The energy storage access switch (energy storage high-voltage GCB switch) can realize large current switching. It will not fail to switch on and off due to a short circuit at the output of the first generator 11 and the second generator 18, like a conventional energy storage circuit breaker, which will eventually cause damage to the energy storage equipment.

[0045] Furthermore, a DC virtual synchronous machine control scheme is adopted in the set A energy storage flexible converter 22 and the set B energy storage flexible converter 25, and the DC virtual synchronous machine rotor mechanical equation is constructed according to the steady-state active power change and the dynamic power fluctuation. Furthermore, in order to reduce the power overshoot when the energy storage responds to the frequency regulation instruction of the thermal power unit, an adaptive virtual damping control scheme is adopted to construct a new DC virtual synchronous machine control scheme containing adaptive virtual damping.

[0046] Furthermore, the energy storage module 33 realizes DC networking through the DC-DC converter unit 32. The DC-DC converter unit 32 has the advantage of stabilizing the DC voltage, ensuring the voltage stability of the DC 975V energy storage bus 31, which is beneficial for the A set of energy storage flexible converters 22 and the B set of energy storage flexible converters 25 to complete power regulation.

[0047] Preferably, a specific implementation method of a thermal power energy storage high-voltage access system of the present invention is: Step 1: Build a distributed energy storage DC networking unit 3, connect n sets of energy storage modules 33 through corresponding DC-DC converter units 32 to form a DC network, and make the energy storage modules 33 converge on the DC 975V energy storage bus 31, where n is a natural integer and is greater than or equal to 2.

[0048] The DC-DC converter unit 32 has the advantage of stabilizing the DC voltage, which can ensure the voltage stability of the DC 975V energy storage bus 31 and lay the foundation for subsequent power regulation.

[0049] Step 2: Based on the distributed energy storage DC networking unit 3 constructed in step 1, a stable DC 975V energy storage bus 31 is obtained, and on this basis, the construction of the energy storage distributed commutation and boosting unit 2 is carried out.

[0050] A set of energy storage boost transformer 21 and a set of energy storage boost transformer 24 are set in the energy storage distributed commutation and boosting unit 2. A DC 975V energy storage bus 31 is used to connect the DC sides of the set of energy storage flexible converter 22 and the set of energy storage flexible converter 25. On the DC side, the set of energy storage flexible converter 22 is connected to the set of energy storage DC circuit breaker 23, and the set of energy storage flexible converter 25 is connected to the set of energy storage DC circuit breaker 26. Compared with the AC circuit breaker, the DC circuit breaker has simpler protection and on-off logic.

[0051] At the same time, a DC virtual synchronous machine control scheme is adopted in the set A energy storage flexible converter 22 and the set B energy storage flexible converter 25 to provide a guarantee for the performance optimization of the energy storage module 33 when responding to frequency regulation.

[0052] Step 3: Based on the distributed energy storage DC networking unit 3 and the distributed energy storage commutation and boosting unit 2 built in the first two steps, set up the thermal power energy storage distributed access unit 1.

[0053] The 22kV energy storage bus 14 of section A is connected to the outlet of the first generator 11 ; the 22kV energy storage bus 17 of section B is connected to the outlet of the second generator 18 .

[0054] The 22kV energy storage busbar 14 of section A is connected to the energy storage access switch 15 of set A; the 22kV energy storage busbar 17 of section B is connected to the energy storage access switch 16 of set B.

[0055] Through the energy storage access switch 15 of set A and the energy storage access switch 16 of set B, the energy storage module A and the energy storage module B can be connected or disconnected respectively. Interlocking logic is set between the energy storage access switch 15 of set A and the energy storage access switch 16 of set B (energy storage high-voltage GCB switch) to ensure that the energy storage module 33 can accurately assist the first generator 11 or the second generator 18 in frequency regulation.

[0056] In step 4, based on the entire system that has been constructed, the distributed energy storage commutation and boosting unit 2 is used to implement a first section of energy storage module 33 to assist the frequency regulation of the first generator 11 and the second generator 18, two thermal power generating units.

[0057] According to the frequency modulation instruction, the energy storage charging / discharging power is accurately configured, and by controlling the set A energy storage flexible converter 22 and the set B energy storage flexible converter 25, the energy storage module 33 performs power regulation control according to the frequency instruction.

[0058] In step 5, building on the auxiliary frequency modulation achieved by energy storage module 33 in step 4, the response performance of energy storage module 33 is further optimized. In energy storage flexible converter set A 22 and energy storage flexible converter set B 25, the DC virtual synchronous machine rotor mechanical equation is constructed based on the steady-state active power change and dynamic power fluctuation. The power regulation amount is determined using droop control and virtual rotor inertia factors, providing a theoretical basis for energy storage module 33 to respond to frequency modulation commands.

[0059] In step 6, an adaptive virtual damping control scheme is adopted based on step 5 to address the power overshoot problem that may occur when the energy storage module 33 responds to the frequency modulation command of the thermal power unit.

[0060] In the frequency increasing stage, the virtual damping is adaptively reduced to quickly reduce the power to the target value; in the angular frequency decreasing stage, the virtual damping is adaptively increased to suppress power oscillation.

[0061] By constructing a DC virtual synchronous machine control scheme containing adaptive virtual damping, the performance of the energy storage module 33 in responding to frequency modulation instructions is further improved.

[0062] Furthermore, the energy storage access switch 15 of set A and the energy storage access switch 16 of set B (energy storage high-voltage GCB switch) are high-current fast switches, and the larger the current, the more difficult it is to disconnect.

[0063] Preferably, step 1 of this embodiment demonstrates a distributed energy storage DC networking method, where the DC-DC converter unit 32 ensures the voltage stability of the DC 975V energy storage bus 31, providing a stable DC power supply foundation for subsequent energy conversion and transmission.

[0064] Preferably, step 2 in this embodiment reflects the conversion and boosting process of the energy storage module 33 from DC to AC.

[0065] As can be seen from step 4, when the system receives the frequency modulation instruction, the energy storage module 33 performs power regulation control according to the frequency instruction by controlling the A set of energy storage flexible converters 22 and the B set of energy storage flexible converters 25 .

[0066] Then, an A-set energy storage access switch 15 is configured on the high-voltage side of the A-set energy storage boosting transformer 21 ; and a B-set energy storage access switch 16 is configured on the high-voltage side of the B-set energy storage boosting transformer 24 .

[0067] It can protect the energy storage equipment in abnormal situations such as short circuit at the outlets of the first generator 11 and the second generator 18, ensuring safe and stable operation of the system.

[0068] In combination with step 5 and step 6, in the set A energy storage flexible converter 22 and the set B energy storage flexible converter 25, the DC virtual synchronous machine rotor mechanical equation is constructed according to the steady-state active power variation and the dynamic power fluctuation.

[0069] Although Figure 1 While the parameter changes in the DC virtual synchronous machine rotor mechanical equations cannot be directly observed, the connection between the energy storage flexible converters A 22 and B 25 and other devices determines the relationship between these parameters. During the frequency regulation process, an adaptive virtual damping control scheme is used to suppress power oscillations.

[0070] Example 2, an embodiment of the present invention, provides a method for high-voltage access to thermal power energy storage, including: The electric energy generated by the generator enters the thermal power energy storage distributed access unit 1 through the outlets of the first generator 11 and the second generator 18 .

[0071] The electric energy enters the energy storage distributed commutation and boosting unit 2 through the 22kV energy storage bus 14 of section A and the 22kV energy storage bus 17 of section B.

[0072] The A-set energy storage flexible converter 22 and the B-set energy storage flexible converter 25 of the energy storage distributed commutation and boosting unit 2 use a DC virtual synchronous machine control solution to optimize the performance of energy storage in responding to frequency regulation.

[0073] The DC virtual synchronous machine control scheme constructs the DC virtual synchronous machine rotor mechanical equation based on the steady-state active power change and dynamic power fluctuation. The power regulation is determined by droop control and virtual rotor inertia. The expression is: , in, is the damping coefficient, is the current value of the AC side output frequency of the energy storage flexible converter, is the target value of the AC side output frequency of the energy storage flexible converter; is the instantaneous active power absorbed or emitted by the virtual rotor inertia, is the virtual moment of inertia; The derivative of the current value output frequency is the frequency change; is the active output of the DC side of the energy storage flexible converter when DC droop control is adopted. is the DC voltage droop coefficient; is the current value of the voltage on the DC side of the energy storage flexible converter; is the initial voltage value of the DC side of the energy storage flexible converter; is the charging and discharging power of the DC side filter capacitor of the energy storage flexible converter, is the DC side filter capacitor value, It is the derivative of the current DC side voltage of the energy storage flexible converter, and the result is the voltage change rate.

[0074] The control scheme of the DC virtual synchronous machine includes an adaptive virtual damping control scheme based on the use of droop control and virtual rotor inertia to determine the power regulation amount. In the frequency increase stage, the virtual damping is adaptively reduced to reduce the power to the target value; in the angular frequency reduction stage, the virtual damping is adaptively increased to suppress power oscillation. The expression is: , in, is the initial virtual damping; is the adaptive virtual damping adjustment coefficient, is the output value of the adaptive virtual damping control scheme; The adaptive virtual damping control scheme is introduced into the DC virtual synchronous machine rotor mechanical equation, and the DC virtual synchronous machine rotor mechanical equation with power oscillation suppression is obtained, which is expressed as: , in, is the output value of the adaptive virtual damping control scheme.

[0075] 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 high voltage access system, characterized in that: include: A thermal power energy storage distributed access 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 A-section 22kV energy storage busbar (14); The outlet of the second generator (18) is connected to the B set energy storage access switch (16) through the B section 22kV energy storage bus (17); The energy storage distributed commutation boost unit (2) comprises an A-set energy storage boost transformer (21) and a B-set energy storage boost transformer (24), wherein the A-set energy storage boost transformer (21) is connected to the A-set energy storage DC circuit breaker (23) via the A-set energy storage flexible converter (22), and the B-set energy storage boost transformer (24) is connected to the B-set energy storage DC circuit breaker (26) via the B-set energy storage flexible converter (25); A distributed energy storage DC networking unit (3) comprises a DC 975V energy storage bus (31), a plurality of DC-DC converter units (32) connected to the DC 975V energy storage bus (31), and an energy storage module (33) connected to the DC-DC converter units (32).

2. A thermal power energy storage high-voltage access system according to claim 1, characterized in that: The A-set energy storage boosting transformer (21) and the B-set energy storage boosting transformer (24) are respectively connected to the A-set energy storage access switch (15) and the B-set energy storage access switch (16) in the thermal power energy storage distributed access unit (1), so that the A-set energy storage boosting transformer (21) interacts with the first generator (11), and the B-set energy storage boosting transformer (24) interacts with the second generator (18).

3. A thermal power energy storage high-voltage access system according to claim 2, characterized in that: The distributed energy storage DC networking unit (3) connects a plurality of energy storage modules (33) to a DC network through correspondingly connected DC-DC converter units (32), and converges the DC 975V energy storage bus (31); One end of the DC 975V energy storage busbar (31) is connected to the DC side of the A-set energy storage flexible converter (22) through the A-set energy storage DC circuit breaker (23), and one end of the DC 975V energy storage busbar (31) away from the A-set energy storage DC circuit breaker (23) is connected to the DC side of the B-set energy storage flexible converter (25) through the B-set energy storage DC circuit breaker (26); A DC virtual synchronous machine control scheme is adopted in the A set of energy storage flexible converters (22) and the B set of energy storage flexible converters (25) to optimize the response performance of energy storage to frequency regulation.

4. A method for high-voltage access to thermal power energy storage, using a high-voltage access system for thermal power energy storage according to any one of claims 1 to 3, characterized in that: Generate electric energy through the first generator (11) and the second generator (18), and transmit the electric energy to the thermal power energy storage distributed access unit (1) through the outlets of the first generator (11) and the second generator (18); The electric energy enters the energy storage distributed commutation and boosting unit (2) through the 22kV energy storage busbar (14) of section A and the 22kV energy storage busbar (17) of section B; The A-set energy storage flexible converter (22) and the B-set energy storage flexible converter (25) of the energy storage distributed commutation and boosting unit (2) adopt a DC virtual synchronous machine control scheme to optimize the response performance of energy storage to frequency regulation.

5. A method for high-voltage access to thermal power energy storage according to claim 4, characterized in that: The DC virtual synchronous machine control scheme constructs the DC virtual synchronous machine rotor mechanical equation based on the steady-state active power change and dynamic power fluctuation, and uses droop control and virtual rotor inertia to determine the power regulation amount. The expression is: ， in, is the damping coefficient, is the current value of the AC side output frequency of the energy storage flexible converter, is the target value of the AC side output frequency of the energy storage flexible converter; is the instantaneous active power absorbed or emitted by the virtual rotor inertia, is the virtual moment of inertia; The derivative of the current value output frequency is the frequency change; is the active output of the DC side of the energy storage flexible converter when DC droop control is adopted. is the DC voltage droop coefficient; is the current value of the voltage on the DC side of the energy storage flexible converter; is the initial voltage value of the DC side of the energy storage flexible converter; is the charging and discharging power of the DC side filter capacitor of the energy storage flexible converter, is the DC side filter capacitor value, It is the derivative of the current DC side voltage of the energy storage flexible converter, and the result is the voltage change rate.

6. A method for high-voltage access to thermal power energy storage according to claim 5, characterized in that: The DC virtual synchronous machine control scheme includes an adaptive virtual damping control scheme based on the use of droop control and virtual rotor inertia to determine the power regulation amount. In the frequency increase stage, the virtual damping is adaptively reduced to reduce the power to the target value; in the angular frequency reduction stage, the virtual damping is adaptively increased to suppress power oscillation. The expression is: ， in, is the output value of the adaptive virtual damping control scheme, is the frequency change, is the initial virtual damping; is the adaptive virtual damping adjustment coefficient; The meaning is or; By introducing the damping into the mechanical equation of the DC virtual synchronous machine rotor, the mechanical equation of the DC virtual synchronous machine rotor with the ability to suppress power oscillation is obtained, which is expressed as: ， in, is the output value of the adaptive virtual damping control scheme.

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