Thermal power generating unit black start system and method

Abstract

The invention relates to a black start system and method for a thermal power generating unit, and belongs to the technical field of black start, and the method comprises the steps: calculating the battery electric quantity required for starting a standby auxiliary machine based on the pre-stored total rated power, starting time and starting times of the standby auxiliary machine when an electromagnetic relay detects that a line between a power grid and the standby auxiliary machine is powered off; the current electric quantity of user side energy storage, the current electric quantity of power grid side energy storage and the current electric quantity of new energy energy storage are obtained; and the first relay, the second relay and the third relay are controlled to be turned off according to the battery electric quantity required for starting the standby auxiliary machine and the electric quantity of the user side energy storage, the power grid side energy storage and the new energy energy storage. User side energy storage, power grid side energy storage and new energy energy storage can be effectively utilized, reliable power supply support is provided for black start of the thermal power generating unit, and it is ensured that the thermal power generating unit can rapidly recover operation under the condition of power grid faults or power failure.

Description

Technical Field

[0001] The present invention relates to the technical field of black start, and in particular to a black start system and method for a thermal power unit. Background Art

[0002] Black start refers to the restoration of the entire power system to normal without relying on external starting power from other systems when all power sources in the power system have stopped operating due to a fault and are in a completely "black" state. "Black start" can assist thermal power units in quickly restoring power to the blackout area and reducing economic losses.

[0003] Thermal power units refer to units that use fossil fuels such as coal, oil, and natural gas as their main energy sources, generate heat energy through combustion, heat water into steam, drive the turbine to rotate, and then drive the generator to generate electricity. Thermal power units are one of the main ways of generating electricity in the world, with advantages such as high power generation efficiency, mature technology, and stable operation. When a thermal power unit is in use, the power grid needs to start its standby auxiliary machine, but when the power grid is out of power, the standby auxiliary machine cannot be started, resulting in the inability of the thermal power unit to start power supply.

[0004] At present, when the power grid is out of power, it is impossible to quickly supply power to the standby auxiliary equipment, resulting in the thermal power units not being started in time to alleviate the power consumption pressure caused by the power outage, causing unnecessary losses.

[0005] To this end, the present invention provides a black start system and method for a thermal power unit to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to provide a black start system and method for a thermal power unit, so as to solve the above technical problems.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, a black start system for a thermal power unit is provided, wherein the thermal power unit is equipped with a standby auxiliary machine, and an electromagnetic relay is connected in series on a transmission line between a power grid and the standby auxiliary machine;

[0009] The system also includes: user-side energy storage, grid-side energy storage and new energy storage;

[0010] A first power supply line is connected between the user-side energy storage and the standby auxiliary machine, and a first relay is connected in series to the first power supply line;

[0011] A second power supply line is connected between the grid-side energy storage and the standby auxiliary machine, and a second relay is connected in series to the second power supply line;

[0012] A third power supply line is connected between the new energy storage and the standby auxiliary machine, and a third relay is connected in series to the third power supply line;

[0013] The system further comprises a main controller, which is electrically connected to the first relay, the second relay and the third relay respectively;

[0014] The main controller is connected to the electromagnetic relay and is used to monitor whether the power grid is out of power, and when the power grid is detected to be out of power, calculate the battery power required for the standby auxiliary machine to complete the startup through pre-stored information;

[0015] The main controller is also connected to the user-side energy storage, the grid-side energy storage and the new energy storage, respectively, to obtain the current power of the user-side energy storage, the grid-side energy storage and the new energy storage, and control the closing of the first relay, the second relay and the third relay according to the required battery power and the power of the user-side energy storage, the grid-side energy storage and the new energy storage;

[0016] The initial states of the first relay, the second relay and the third relay are all open circuit.

[0017] Furthermore, the system also includes:

[0018] Power input unit, used to input the total rated power of the standby auxiliary machine;

[0019] The start times input unit is used to input the average times of completing the black start of the thermal power unit and starting the standby auxiliary machine in a single operation;

[0020] The start time input unit is used to input the average time of starting the standby auxiliary machine in a single process of completing the black start of the thermal power unit;

[0021] The main controller is also connected to the power input unit, the start time input unit and the start times input unit respectively, so as to calculate the battery power required for the standby auxiliary machine to complete the start.

[0022] Furthermore, the main controller is connected to a display screen, which is used to display the power of user-side energy storage, grid-side energy storage and new energy storage.

[0023] Furthermore, the main controller is connected to a communication module, and the main controller is connected to a remote control terminal via the communication module.

[0024] Furthermore, the main controller is connected to an alarm, which is used to control the alarm to sound an alarm when a power outage in the power grid is detected, so as to remind the staff to connect to the external energy storage to power the standby auxiliary machine.

[0025] In a second aspect, a method for a black start system of a thermal power plant according to the above aspects is provided, the method comprising:

[0026] When the electromagnetic relay detects a power failure in the line between the power grid and the standby auxiliary machine, the battery power required for starting the standby auxiliary machine is calculated based on the total rated power, starting time and starting number of the standby auxiliary machine stored in advance;

[0027] Obtain the current power of user-side energy storage, grid-side energy storage and new energy storage respectively;

[0028] The closing of the first relay, the second relay and the third relay is controlled according to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy energy storage.

[0029] Furthermore, according to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy storage, the closing of the first relay, the second relay and the third relay is controlled, including:

[0030] The power of user-side energy storage, grid-side energy storage and new energy energy storage is sorted by power size and accumulated in sequence from large to small until the accumulated power reaches the battery power required for starting the standby auxiliary machine, thereby controlling the closure of the first relay, the second relay and the third relay.

[0031] Furthermore, the calculation formula for calculating the battery power required for starting the standby auxiliary machine is:

[0032]

[0033] Where S represents the battery power required for black start of thermal power unit, P 总 represents the total rated power of the standby auxiliary machine, and m represents the average number of times the standby auxiliary machine is started during the black start of the thermal power unit. Indicates the average time for a single start of the standby auxiliary engine.

[0034] The beneficial effects of the present invention are as follows: by installing an electromagnetic relay between the power grid and the thermal power unit, when the power grid is out of power, the main controller calculates the power required for the black start of the thermal power unit through pre-stored information, and the main controller obtains the power of new energy storage, user-side storage and power grid-side storage, and controls the closure of the first relay, the second relay and the third relay in an orderly manner according to the amount of power, so as to power the standby auxiliary machine of the thermal power unit, so that the thermal power unit can be black started and resume operation, so as to timely alleviate the power consumption pressure caused by the power outage of the power grid and avoid unnecessary losses.

[0035] These and other objects, features and advantages of the present invention will be fully reflected in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The schematic diagram of the structure of the black start system of the thermal power unit of the present invention is shown.

[0037] Figure 2 The schematic diagram of the electric control principle of the black start system of the thermal power unit of the present invention is shown. DETAILED DESCRIPTION

[0038] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0039] It should be understood by those skilled in the art that, in the disclosure of the specification, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device including a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. Therefore, the above terms should not be understood as limiting the present invention.

[0040] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0041] The normal operation of thermal power units requires the operation of standby auxiliary machines, including feedwater pumps, condensate pumps, blowers, induced draft fans and coal mills. The setting of standby auxiliary machines is to ensure that the thermal power units can be put into use and generate electricity in time when there is a fault in the power grid or the power grid needs to be repaired and causes a power outage, effectively alleviating the power shortage caused by a fault in the power grid or a power outage caused by the need for maintenance. It can improve the reliability and operating efficiency of thermal power units to reduce economic losses caused by power outages. Standby auxiliary machines are an important guarantee for the operation of thermal power units. In thermal power units, feedwater pumps, condensate pumps, blowers, induced draft fans and coal mills work together to ensure the normal operation of thermal power units.

[0042] refer to Figure 1 and Figure 2A black start system for a thermal power unit according to a preferred embodiment of the present invention will be described in detail below. A black start system for a thermal power unit, the thermal power unit is equipped with a standby auxiliary machine, the standby auxiliary machine is used to start the thermal power unit, and an electromagnetic relay is connected in series on the transmission line between the power grid and the standby auxiliary machine. The electromagnetic relay is a switch controlled by an electromagnet. When the coil of the electromagnetic relay is energized, the electromagnet of the electromagnetic relay generates magnetism, attracts the armature, and makes the moving contact of the electromagnetic relay contact with the static contact of the electromagnetic relay, thereby closing the circuit. Conversely, when the coil of the electromagnetic relay is de-energized, the electromagnet of the electromagnetic relay loses magnetism, the armature of the electromagnetic relay is reset under the action of the spring, and the contacts are opened or closed, thereby achieving the purpose of switching the circuit on and off.

[0043] The system also includes: user-side energy storage, grid-side energy storage and new energy energy storage.

[0044] User-side energy storage, grid-side energy storage and new energy energy storage are all used to provide power for the black start of thermal power units, and the power of user-side energy storage, grid-side energy storage and new energy energy storage is sufficient to meet the electricity demand for the black start of thermal power units.

[0045] A first power supply line is connected between the user-side energy storage and the standby auxiliary machine, and a first relay is connected in series to the first power supply line.

[0046] A second power supply line is connected between the grid-side energy storage and the standby auxiliary machine, and a second relay is connected in series to the second power supply line.

[0047] A third power supply line is connected between the new energy storage and the standby auxiliary machine, and a third relay is connected in series on the third power supply line.

[0048] The system further comprises a main controller, which is electrically connected to the first relay, the second relay and the third relay respectively, and is used for controlling the closing and opening of the first relay, the second relay and the third relay.

[0049] The main controller is connected to the electromagnetic relay and is used to monitor whether the power grid is out of power. When the power grid is out of power, the battery power required for the standby auxiliary machine to complete the startup is calculated through pre-stored information. Specifically, when the power grid is out of power due to a fault or due to maintenance, the coil on the electromagnetic relay will lose power, and the moving contact of the electromagnetic relay will operate due to the loss of power in the coil, so that the main controller can detect the power outage of the power grid.

[0050] The main controller is also connected to the user-side energy storage, the grid-side energy storage and the new energy storage, respectively, to obtain the current power of the user-side energy storage, the grid-side energy storage and the new energy storage, and control the closing of the first relay, the second relay and the third relay according to the required battery power and the power of the user-side energy storage, the grid-side energy storage and the new energy storage. The initial state of the first relay, the second relay and the third relay is open circuit.

[0051] When the main controller detects that the power grid is out of power due to a fault or maintenance, the main controller obtains the current power of the user-side energy storage, the grid-side energy storage and the new energy storage respectively, and calculates the battery power required for the black start of the thermal power unit, and controls the closure of the first relay, the second relay and the third relay according to the required battery power and the power of the user-side energy storage, the grid-side energy storage and the new energy storage.

[0052] Exemplarily, the system further includes a power input unit for inputting a total rated power of the standby auxiliary machine.

[0053] As you can understand, the rated power is the power on the nameplate when the equipment leaves the factory.

[0054] The calculation formula for the total rated power of the standby auxiliary machine in this embodiment is:

[0055] P 总 =p a +p b +p c +p d +p e

[0056] Where P 总 is the total rated power of the standby auxiliary machine, p a is the rated power of the feed water pump, p b is the rated power of the condensate pump, p c is the rated power of the blower, p d is the rated power of the induced draft fan, p e is the rated power of the coal mill.

[0057] The system further comprises a start-up number input unit and a start-up time input unit.

[0058] The start times input unit is used to input the average number of times a single black start of a thermal power unit is completed and the standby auxiliary machine is started.

[0059] The start time input unit is used to input the average time of a single start of a standby auxiliary machine during a single black start of a thermal power unit.

[0060] It is understandable that when the standby auxiliary machine assists the thermal power unit to complete the black start, there may be a situation where the standby auxiliary machine is started multiple times.

[0061] The start-up times input unit is used to input the average number of times the standby auxiliary machine is started when the thermal power unit completes the black start. The calculation steps of the average number of times the standby auxiliary machine is started include:

[0062] Record the number of times the standby auxiliary machine is started when the Xth thermal power unit completes the black start m X ; Wherein, X = 1, 2, ..., d, d means that the dth thermal power unit completes the black start;

[0063] Calculate the average number of times the standby auxiliary machine is started during the black start of the thermal power unit d times The calculation formula is:

[0064]

[0065] In the formula, m d Indicates the number of times the standby auxiliary machine is started when the dth thermal power unit completes the black start;

[0066] The start time input unit inputs the average time of a single start of the standby auxiliary machine when the thermal power unit completes the black start. The average calculation steps of a single start of the standby auxiliary machine include:

[0067] Record the number of times the standby auxiliary machine is started when the Xth thermal power unit completes the black start m X ; Where X = 1, 2, ..., d;

[0068] And record the time t of starting the standby auxiliary machine for the i-th time when the X-th thermal power unit completes the black start Xi ; where i = 1, 2, ..., m X ;

[0069] The number of times m when the backup auxiliary machine is started when the Xth thermal power unit completes the black start based on the records X and the time t of starting the i-th standby auxiliary machine during the black start of the X-th thermal power unit Xi , calculate the average time of a single start of the standby auxiliary machine when the Xth thermal power unit completes the black start The calculation formula is:

[0070]

[0071] Where, t XmX Indicates the mth time when the Xth thermal power unit completes the black start X The time to start the standby auxiliary engine for the first time;

[0072] The average time to start the standby auxiliary machine when the Xth thermal power unit completes the black start Calculate the average time to start the standby auxiliary machine during the black start of the thermal power unit d times, that is, the average time to start the standby auxiliary machine once The calculation formula is:

[0073]

[0074] It indicates the average time to start the standby auxiliary machine when the dth thermal power unit completes the black start.

[0075] The main controller is also connected to the power input unit, the start time input unit and the start times input unit respectively, so as to calculate the battery power required for the standby auxiliary machine to complete the start.

[0076] Exemplarily, the main controller is connected to a display screen, which is used to display the power of user-side energy storage, grid-side energy storage and new energy storage.

[0077] Exemplarily, the main controller is connected to a communication module, and the main controller is connected to a remote control terminal through the communication module, for uploading the monitored power of user-side energy storage, grid-side energy storage and new energy storage to the remote terminal.

[0078] The main controller is connected to an alarm, which is used to control the alarm to sound an alarm when a power outage is detected in the power grid, reminding the staff to connect to the external energy storage to power the standby auxiliary machine.

[0079] Exemplarily, the main controller is connected to a micro switch and is used to calculate the battery power required for the standby auxiliary machine to complete starting through a power input unit, a start time input unit and a start number input unit when a power outage in the power grid is detected.

[0080] Specifically, the paddle of the microswitch is in contact with the moving contact of the electromagnetic relay. When the power grid is cut off due to a fault or due to maintenance, the coil on the electromagnetic relay will lose power, and the moving contact of the electromagnetic relay will move due to the loss of power to the coil. At this time, the contact state between the moving contact of the electromagnetic relay and the paddle of the microswitch changes, and the relative position of the paddle of the microswitch and the moving contact of the electromagnetic relay changes. The microswitch detects the change in the relative position of the paddle and the moving contact of the electromagnetic relay, and transmits the detected position change signal to the main controller.

[0081] In specific implementation, a signal converter is connected to the output end of the micro switch. In this embodiment, the signal converter is an analog signal to digital signal converter, which is used to convert the mechanical action of the micro switch into an electrical signal. The electrical signal in this embodiment is a digital signal.

[0082] The signal converter transmits the electrical signal to the main controller via wired or wireless means. Based on comprehensive consideration of factors such as the on-site environment, communication distance, and transmission rate, in this embodiment, a wired connection is adopted between the signal converter and the main controller, specifically an RS-485 communication method that is suitable for long-distance, high-speed serial data communication and has strong anti-interference capabilities.

[0083] When the relative position of the paddle of the micro switch and the moving contact of the electromagnetic relay changes, that is, when the power grid is powered off due to a fault or due to maintenance, the micro switch detects the change in the relative position of the paddle and the moving contact of the electromagnetic relay and transmits the detected position change signal to the main controller.

[0084] In specific implementation, a signal converter is connected to the output end of the micro switch, and the signal converter transmits the electrical signal to the main controller by wire. The main controller then obtains the current power of the user-side energy storage, the grid-side energy storage and the new energy storage, respectively, and calculates the battery power required for the black start of the thermal power unit, and controls the closure of the first relay, the second relay and the third relay according to the required battery power and the power of the user-side energy storage, the grid-side energy storage and the new energy storage.

[0085] In this embodiment, the model of the micro switch is CZ-7124. Specifically, the paddle of the micro switch is in contact with the moving contact of the electromagnetic relay. When the power grid is cut off due to a fault or maintenance, the coil on the electromagnetic relay will lose power, and the moving contact of the electromagnetic relay will move due to the loss of power to the coil. At this time, the contact state between the moving contact of the electromagnetic relay and the paddle of the micro switch changes, and the relative position of the paddle of the micro switch and the moving contact of the electromagnetic relay changes. The micro switch detects that the relative position of the paddle and the moving contact of the electromagnetic relay has changed.

[0086] The present invention also provides a method based on the black start system of a thermal power plant according to the above aspects, the method comprising:

[0087] When the electromagnetic relay detects a power failure in the line between the power grid and the standby auxiliary machine, the battery power required for starting the standby auxiliary machine is calculated based on the total rated power, starting time and starting number of the standby auxiliary machine stored in advance;

[0088] Obtain the current power of user-side energy storage, grid-side energy storage and new energy storage respectively;

[0089] The closing of the first relay, the second relay and the third relay is controlled according to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy energy storage.

[0090] The present invention can effectively utilize user-side energy storage, grid-side energy storage and new energy energy storage to provide reliable power supply support for the black start of thermal power units, ensuring that the thermal power units can quickly resume operation in the event of a grid failure or power outage.

[0091] According to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy storage, the closing of the first relay, the second relay and the third relay is controlled, including:

[0092] The power of user-side energy storage, grid-side energy storage and new energy energy storage is sorted by power size and accumulated in sequence from large to small until the accumulated power reaches the battery power required for starting the standby auxiliary machine, thereby controlling the closure of the first relay, the second relay and the third relay.

[0093] Specifically, when the main controller detects that the line between the power grid and the standby auxiliary machine is powered off, the relay corresponding to the energy storage ranked first in terms of power is controlled to close, and then it is determined whether the power of the energy storage ranked first in terms of power meets the power required for starting the standby auxiliary machine. If it does, the control ends; if not, the relay corresponding to the energy storage ranked second in terms of power continues to be controlled to close, and then it is determined whether the power of the energy storage ranked first in terms of power plus the power of the energy storage ranked second in terms of power meets the power required for starting the standby auxiliary machine. If it does, the control ends; if not, the relay corresponding to the energy storage ranked third in terms of power continues to be controlled to close.

[0094] In this embodiment, the calculation formula for calculating the battery power required for starting the standby auxiliary machine is:

[0095]

[0096] Where S represents the battery power required for black start of thermal power unit, P 总 Indicates the total rated power of the standby auxiliary machine, Indicates the average number of times the standby auxiliary machine is started during the black start of the thermal power unit It represents the average time of starting the standby auxiliary machine once. Among them, the total rated power P of the standby auxiliary machine is input by the power input unit. 总 , use the start time input unit to input the average time for a single start of the standby auxiliary machine Use the start count input unit to input the average number of times the standby auxiliary engine is started.

[0097] The calculation formula for the total rated power of the standby auxiliary machine is:

[0098] P 总 =p a +p b +p c +p d +p e

[0099] Where P 总 is the total rated power of the standby auxiliary machine, p a is the rated power of the feed water pump, p b is the rated power of the condensate pump, p c is the rated power of the blower, p d is the rated power of the induced draft fan, pe is the rated power of the coal mill.

[0100] It is understandable that when the standby auxiliary machine assists the thermal power unit to complete the black start, there will be multiple times of starting the standby auxiliary machine.

[0101] The start-up times input unit is used to input the average number of times the standby auxiliary machine is started when the thermal power unit completes the black start. The calculation steps of the average number of times the standby auxiliary machine is started include:

[0102] Record the number of times the standby auxiliary machine is started when the Xth thermal power unit completes the black start m X ; Where X = 1, 2, ..., d;

[0103] Based on the records, when the Xth thermal power unit completes the black start, the number of times the standby auxiliary machine is started is m X , calculate the average number of times the standby auxiliary machine is started during the black start of the thermal power unit d times The calculation formula is:

[0104]

[0105] In the formula, m d Indicates the number of times the standby auxiliary machine is started when the dth thermal power unit completes the black start;

[0106] The start time input unit inputs the average time of a single start of the standby auxiliary machine when the thermal power unit completes the black start. The average calculation steps of a single start of the standby auxiliary machine include:

[0107] Record the number of times the standby auxiliary machine is started when the Xth thermal power unit completes the black start m X ; Where X = 1, 2, ..., d;

[0108] And record the time t of starting the standby auxiliary machine for the i-th time when the X-th thermal power unit completes the black start Xi ; where i = 1, 2, ..., m X ;

[0109] The number of times m when the backup auxiliary machine is started when the Xth thermal power unit completes the black start based on the records X and the time t of starting the standby auxiliary engine for the i-th time Xi , calculate the average time of a single start of the standby auxiliary machine when the Xth thermal power unit completes the black start The calculation formula is:

[0110]

[0111] Where, t XmX Indicates the mth time when the Xth thermal power unit completes the black start X The time to start the standby auxiliary engine for the first time;

[0112] The average time to start the standby auxiliary machine when the Xth thermal power unit completes the black start Calculate the average time to start the standby auxiliary machine during the black start of the thermal power unit d times, that is, the average time to start the standby auxiliary machine once The calculation formula is:

[0113]

[0114] It indicates the average time to start the standby auxiliary machine when the dth thermal power unit completes the black start.

[0115] It should be noted that the terms "first, second, third" in the present invention are only used for descriptive purposes and do not indicate any order. They cannot be understood as indicating or implying relative importance. These terms can be interpreted as names.

[0116] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The advantages of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A black start system for a thermal power unit, the thermal power unit is equipped with a standby auxiliary machine, characterized in that: An electromagnetic relay is connected in series on the transmission line between the power grid and the standby auxiliary machine; The system also includes: user-side energy storage, grid-side energy storage and new energy storage; A first power supply line is connected between the user-side energy storage and the standby auxiliary machine, and a first relay is connected in series to the first power supply line; A second power supply line is connected between the grid-side energy storage and the standby auxiliary machine, and a second relay is connected in series to the second power supply line; A third power supply line is connected between the new energy storage and the standby auxiliary machine, and a third relay is connected in series to the third power supply line; The system further comprises a main controller, which is electrically connected to the first relay, the second relay and the third relay respectively; The main controller is connected to the electromagnetic relay and is used to monitor whether the power grid is out of power, and when the power grid is detected to be out of power, calculate the battery power required for the standby auxiliary machine to complete the startup through pre-stored information; The main controller is also connected to the user-side energy storage, the grid-side energy storage and the new energy storage, respectively, for obtaining the current power of the user-side energy storage, the grid-side energy storage and the new energy storage, and controlling the closing of the first relay, the second relay and the third relay according to the required battery power and the power of the user-side energy storage, the grid-side energy storage and the new energy storage; The initial states of the first relay, the second relay and the third relay are all open circuit.

2. The system according to claim 1, characterized in that The system further comprises: Power input unit, used to input the total rated power of the standby auxiliary machine; The start times input unit is used to input the average times of completing the black start of the thermal power unit and starting the standby auxiliary machine in a single operation; The start time input unit is used to input the average time of starting the standby auxiliary machine in a single process of completing the black start of the thermal power unit; The main controller is also connected to the power input unit, the start time input unit and the start times input unit respectively, so as to calculate the battery power required for the standby auxiliary machine to complete the start.

3. The system according to claim 1, characterized in that The main controller is connected to a display screen, which is used to display the power of user-side energy storage, grid-side energy storage and new energy storage.

4. The system according to claim 3, characterized in that The main controller is connected to a communication module, and the main controller is connected to a remote control terminal via the communication module.

5. The system according to claim 1, wherein: The main controller is connected to an alarm, which is used to control the alarm to sound an alarm when a power outage is detected in the power grid, reminding the staff to connect to the external energy storage to power the standby auxiliary machine.

6. A black start method based on the system according to any one of claims 1 to 5, characterized in that: The method comprises: When the electromagnetic relay detects a power failure in the line between the power grid and the standby auxiliary machine, the battery power required for starting the standby auxiliary machine is calculated based on the total rated power, starting time and starting number of the standby auxiliary machine stored in advance; Obtain the current power of user-side energy storage, grid-side energy storage and new energy storage respectively; The closing of the first relay, the second relay and the third relay is controlled according to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy energy storage.

7. The black start method according to claim 6, characterized in that: According to the battery power required for starting the standby auxiliary machine, as well as the power of the user-side energy storage, the grid-side energy storage and the new energy storage, the closing of the first relay, the second relay and the third relay is controlled, including: The power of user-side energy storage, grid-side energy storage and new energy energy storage is sorted by power size and accumulated in sequence from large to small until the accumulated power reaches the battery power required for starting the standby auxiliary machine, thereby controlling the closure of the first relay, the second relay and the third relay.

8. The black start method according to claim 7, characterized in that: The calculation formula for calculating the battery power required for starting the standby auxiliary engine is: In the formula, S represents the battery power required for the black start of the thermal power unit, P 总 Indicates the total rated power of the standby auxiliary machine, Indicates the average number of times the standby auxiliary machine is started during the black start of the thermal power unit Indicates the average time for a single start of the standby auxiliary engine.

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