A black start system and method for a thermal power plant integrating a small gas turbine with FCB function

Abstract

The present invention discloses a black start system and method for a thermal power plant combined with a small gas turbine having FCB function, including a coal-fired generator, a main transformer, a station service transformer, coal-fired unit station service auxiliary equipment and other loads, gas turbine station service auxiliary equipment and other loads, a station service incoming breaker, a station service 6 kV bus section, a gas turbine system, a security transformer, a security PC section bus, a security MCC section feeder breaker, a security MCC section incoming breaker, a security MCC section bus, a diesel generator incoming breaker, a diesel generator, a synchronization device, a gas turbine TCS system and a backup power automatic switching device. The gas turbine system includes a gas turbine generator and a gas turbine generator outlet breaker. This system and method solve the disadvantages of the lack of hydropower resources or large gas turbine units in the northern region, and the system has high safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of black start of thermal power plants, and relates to a black start system and method for a thermal power plant combined with a small gas turbine with FCB function. Background Art

[0002] Black start refers to the process that after the power system shuts down due to faults, without relying on the help of other networks, by starting the power sources with self-starting ability in the system to drive the power sources without self-starting ability, so that they can resume power generation ability again and form a small system in parallel with the black start power source. Its goal is to achieve the safe start of the shutdown units in the shortest time and provide power support for the subsequent recovery of the system.

[0003] In recent years, whether the power grid has the black start ability has gradually become an important indicator for assessing the safety of the power grid in China. Each regional and provincial company has increased the investment in the research work of the black start of the power grid, formulated black start plans adapted to the actual situation of the regional power grid, and successively carried out black start tests and achieved success.

[0004] According to the black start power source selection principle, power plants with high access voltage levels, close to important load centers and conducive to quickly restoring other power sources should be given priority to be considered as black start power sources. Then, units with high rated power, good starting and regulating performance, and the ability of leading phase operation are selected in the power plant. Hydro-generating units and gas turbine units are the first choices for black start power sources because of their low auxiliary power load and fast starting speed, and they can complete self-starting in 5 - 10 minutes. However, restricted by regional resource conditions, for example, there are few hydropower stations in the northwest region, and it is less likely to select hydro-generating units as black start power sources. And due to the low access system voltage and limited power transmission capacity of new energy power stations, and generally the stations are relatively scattered, their advantages as black start power sources are not prominent. Thermal power generating units generally have large capacities, high access voltage levels, and certain leading phase capabilities, and are very suitable as black start power sources in the northern regions lacking water resources. However, the starting process flow is complex, the auxiliary equipment power is large, the required auxiliary power is large, and the requirements for generating units with self-starting ability are very high. Using large diesel generating units in parallel as the self-starting power source of thermal power plants not only has a large investment, but also will cause waste of resources when the diesel generating units are idle during the normal operation of the units. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art, and provide a black start system and method for a thermal power plant combined with a small gas turbine with FCB function. The system and method solve the disadvantages of lacking hydropower resources or large gas turbine units in the northern regions, and the safety of the system is relatively high.

[0006] To achieve the above object, the black start system of a thermal power plant combined with a small gas turbine with FCB function includes a coal-fired generator, a main transformer, a station service transformer, auxiliary equipment and other loads of the coal-fired unit, auxiliary equipment and other loads of the gas turbine, a station service incoming breaker, a 6kV station service bus section, a gas turbine system, a security transformer, a security PC section bus, a security MCC section feeder breaker, a security MCC section incoming breaker, a security MCC section bus, a diesel generator incoming breaker, a diesel generator, a synchronization device, a gas turbine TCS system and an automatic bus transfer device. The gas turbine system includes a gas turbine generator and a gas turbine generator outlet breaker;

[0007] One end of the coal-fired generator is connected to one side of the main transformer and one side of the station service transformer respectively. The other side of the main transformer is connected to the power grid system. The other side of the station service transformer is connected to the 6kV station service bus section through the station service incoming breaker; the gas turbine generator is connected to the 6kV station service bus section through the gas turbine generator outlet breaker. Auxiliary equipment and other loads of the coal-fired unit are connected to the 6kV station service bus section. Auxiliary equipment and other loads of the gas turbine are connected to the 6kV station service bus section. The 6kV station service bus section is connected to the security PC section bus through the security transformer;

[0008] The security PC section bus is connected to the security MCC section bus through the security MCC section feeder breaker and the security MCC section incoming breaker; the diesel generator is connected to the security MCC section bus through the diesel generator incoming breaker;

[0009] The synchronization device is connected to the station service incoming breaker and the 6kV station service bus section; the gas turbine TCS system is connected to the gas turbine system; the automatic bus transfer device is connected to the security MCC section incoming breaker and the diesel generator incoming breaker.

[0010] The main transformer is connected to the power grid system through the main transformer high-voltage side breaker.

[0011] The 6kV station service bus section is connected to the security PC section bus through the security PC section incoming breaker and the security transformer.

[0012] The diesel generator is connected to the security MCC section bus through the diesel generator outlet breaker and the diesel generator incoming breaker.

[0013] Auxiliary equipment and other loads of the coal-fired unit are connected to the 6kV station service bus section through the coal-fired unit station service load breaker.

[0014] Auxiliary equipment and other loads of the gas turbine are connected to the 6kV station service bus section through the gas turbine station service load breaker.

[0015] The black start method of a thermal power plant combined with a small gas turbine with FCB function according to the present invention includes the following steps:

[0016] 1) When the unit is operating normally, the coal-fired generator is connected to the grid for power generation, the main transformer high-voltage side circuit breaker is in the closed position, the plant service incoming circuit breaker is in the closed position, the coal-fired unit plant service load circuit breaker is in the closed position, the gas turbine plant service load circuit breaker is in the closed position, the gas turbine generator outlet circuit breaker is in the closed position, and the 6kV bus section of the plant service is jointly powered by the plant service transformer and the gas turbine generator;

[0017] 2) The security PC section incoming circuit breaker is in the closed position, the security MCC section feeder circuit breaker is in the closed position, the security MCC section incoming circuit breaker is in the closed position, the diesel generator incoming circuit breaker is in the open position, the diesel generator outlet circuit breaker is in the open position, and the voltages of the security PC section bus and the security MCC section bus are normal;

[0018] 3) The standby power supply automatic switching device is normally put into operation, and the diesel generator is in the cold standby state;

[0019] 4) When frequency modulation is required during the oscillation of the gas turbine system, the gas turbine TCS system issues a frequency modulation command to adjust the gas turbine system, and adjusts the output of the gas turbine generator for frequency modulation;

[0020] 5) When the oscillation of the gas turbine system causes the coal-fired unit to be disconnected from the grid, the zero-power generator tripping protection of the coal-fired generator operates, and trips the main transformer high-voltage side circuit breaker and the plant service incoming circuit breaker;

[0021] 6) After the gas turbine TCS system receives the command to enter the FCB mode, it adjusts the output of the gas turbine system according to the load sizes of the plant service auxiliary equipment and other loads of the coal-fired unit and the plant service auxiliary equipment and other loads of the gas turbine;

[0022] 7) After the gas turbine system enters the FCB mode, when the gas turbine generator can maintain the stable operation of the plant service auxiliary equipment and other loads of the coal-fired unit and the plant service auxiliary equipment and other loads of the gas turbine, it proceeds to step 8), otherwise, it proceeds to step 9);

[0023] 8) After the gas turbine generator operates stably, restart the coal-fired unit. After the coal-fired generator rebuilds voltage, use the synchronization device to close the plant service incoming circuit breaker, and at the same time close the main transformer high-voltage side circuit breaker to charge the line. The gas turbine generator serves as the black start power source;

[0024] 9) The gas turbine generator trips and trips the gas turbine generator outlet circuit breaker, the 6kV bus section of the plant service loses voltage, and trips the coal-fired unit plant service load circuit breaker and the gas turbine plant service load circuit breaker;

[0025] 10) The standby power supply automatic switching device issues a command to start and build voltage for the diesel generator. After the diesel generator builds voltage successfully, automatically close the diesel generator outlet circuit breaker. The standby power supply automatic switching device trips the security MCC section incoming circuit breaker and closes the diesel generator incoming circuit breaker. The security MCC section bus is powered by the diesel generator;

[0026] 11) After there is no abnormality in the security MCC section busbar, close the incoming breaker of the security MCC section. The security PC section busbar is powered by the diesel generator. After there is no abnormality in the security PC section busbar, close the incoming breaker of the security PC section. The 6kV busbar section of the power plant is powered by the diesel generator;

[0027] 12) Close the breaker of the gas turbine auxiliary load of the power plant, sequentially start the auxiliary equipment and other loads of the gas turbine, and then start the gas turbine generator. After the gas turbine generator builds voltage, close the outlet breaker of the gas turbine generator, and the gas turbine generator supplies power to the 6kV busbar section of the power plant;

[0028] 13) Open the incoming breaker and the outlet breaker of the diesel generator, and the diesel generator withdraws;

[0029] 14) Close the breaker of the auxiliary load of the coal-fired unit of the power plant, sequentially start the auxiliary equipment and other loads of the coal-fired unit, and then start the coal-fired generator. After the coal-fired generator builds voltage, use the synchronization device to close the incoming breaker of the auxiliary power;

[0030] 15) After the operating parameters of the coal-fired generator are normal, close the breaker on the high-voltage side of the main transformer to charge the line, and the coal-fired generator serves as the black start power source.

[0031] The present invention has the following beneficial effects:

[0032] The black start system and method for a thermal power plant integrating a small gas turbine with FCB function according to the present invention can reduce the auxiliary power rate of the thermal power plant during normal operation. When the external network power supply is lost, the coal-fired generator first enters the FCB self-holding auxiliary power and serves as the self-starting power source of the thermal power plant to start the thermal power plant. When the FCB function fails to self-hold the auxiliary power and causes the unit to trip, the diesel generator set provides power to quickly restart the gas turbine and restore the auxiliary power system of the thermal power plant to start the thermal power plant. The investment cost is low, the construction period is short, the single-unit power is large and can be effectively utilized, and it can effectively solve the disadvantages of the lack of hydropower resources or large gas turbine units in the northern region, and greatly improve the system safety. Description of the Drawings

[0033] Figure 1 is a structural schematic diagram of the present invention;

[0034] Figure 2 is a flow chart of the present invention.

[0035] Among them, 1 is a coal-fired generator, 2 is a main transformer, 3 is a main transformer high-voltage side circuit breaker, 4 is a station service transformer, 5 is the auxiliary equipment and other loads of the coal-fired unit for the plant use, 6 is the auxiliary equipment and other loads of the gas turbine unit for the plant use, 7 is a station service incoming circuit breaker, 8 is a coal-fired unit plant use load circuit breaker, 9 is a gas turbine unit plant use load circuit breaker, 10 is a 6 kV bus section of the plant use, 11 is a gas turbine generator, 12 is a security PC section incoming circuit breaker, 13 is a gas turbine generator outlet circuit breaker, 14 is a security transformer, 15 is a security PC section bus, 16 is a security MCC section feeder circuit breaker, 17 is a security MCC section incoming circuit breaker, 18 is a security MCC section bus, 19 is a diesel generator incoming circuit breaker, 20 is a diesel generator outlet circuit breaker, 21 is a diesel generator, 22 is a synchronization device, 23 is a gas turbine TCS system, and 24 is an automatic standby power supply device. Detailed implementation manners

[0036] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present invention disclosure. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0037] The structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0038] Refer to Figure 1, the black start system of the thermal power plant with a small gas turbine having the FCB function according to the present invention includes a coal-fired generator 1, a main transformer 2, a main transformer high-voltage side circuit breaker 3, a station service transformer 4, coal-fired unit station service auxiliary equipment and other loads 5, gas turbine station service auxiliary equipment and other loads 6, a station service incoming line circuit breaker 7, a coal-fired unit station service load circuit breaker 8, a gas turbine station service load circuit breaker 9, a station service 6kV bus section 10, a gas turbine generator 11, a security PC section incoming line circuit breaker 12, a gas turbine generator outlet circuit breaker 13, a security transformer 14, a security PC section bus 15, a security MCC section feeder circuit breaker 16, a security MCC section incoming line circuit breaker 17, a security MCC section bus 18, a diesel generator incoming line circuit breaker 19, a diesel generator outlet circuit breaker 20, a diesel generator 21, a synchronization device 22, a gas turbine TCS system 23 and an automatic bus transfer device 24;

[0039] One end of the coal-fired generator 1 is respectively connected to one side of the main transformer 2 and one side of the station service transformer 4. The other side of the main transformer 2 is connected to the power grid system through the main transformer high-voltage side circuit breaker 3. The other side of the station service transformer 4 is connected to the station service 6kV bus section 10 through the station service incoming line circuit breaker 7;

[0040] The gas turbine generator 11 is connected to the station service 6kV bus section 10 through the gas turbine generator outlet circuit breaker 13. The coal-fired unit station service auxiliary equipment and other loads 5 are connected to the station service 6kV bus section 10 through the coal-fired unit station service load circuit breaker 8. The gas turbine station service auxiliary equipment and other loads 6 are connected to the station service 6kV bus section 10 through the gas turbine station service load circuit breaker 9;

[0041] The station service 6kV bus section 10 is connected to the security PC section bus 15 through the security PC section incoming line circuit breaker 12 and the security transformer 14;

[0042] The security PC section bus 15 is connected to the security MCC section bus 18 through the security MCC section feeder circuit breaker 16 and the security MCC section incoming line circuit breaker 17;

[0043] The diesel generator 21 is connected to the power supply to the security MCC section bus 18 through the diesel generator outlet circuit breaker 20 and the diesel generator incoming line circuit breaker 19;

[0044] The synchronization device 22 is connected to the station service incoming line circuit breaker 7 and the station service 6kV bus section 10;

[0045] The gas turbine TCS system 23 is connected to the gas turbine system, and the gas turbine system includes the gas turbine generator 11 and the gas turbine generator outlet circuit breaker 13;

[0046] The automatic bus transfer device 24 is connected to the security MCC section incoming line circuit breaker 17 and the diesel generator incoming line circuit breaker 19.

[0047] ReferenceFigure 2 , the black start method of the thermal power plant combined with a small gas turbine with FCB function according to the present invention includes the following steps:

[0048] 1) When the unit is operating normally, the coal-fired generator 1 is connected to the grid for power generation, the main transformer high-voltage side circuit breaker 3 is in the closed position, the plant incoming line circuit breaker 7 is in the closed position, the coal-fired unit plant load circuit breaker 8 is in the closed position, the gas turbine plant load circuit breaker 9 is in the closed position, the gas turbine generator outlet circuit breaker 13 is in the closed position, and the 6kV bus section 10 of the plant is powered jointly by the plant transformer 4 and the gas turbine generator 11;

[0049] 2) The security PC section incoming line circuit breaker 12 is in the closed position, the security MCC section feeder circuit breaker 16 is in the closed position, the security MCC section incoming line circuit breaker 17 is in the closed position, the diesel generator incoming line circuit breaker 19 is in the open position, the diesel generator outlet circuit breaker 20 is in the open position, and the voltages of the security PC section bus 15 and the security MCC section bus 18 are normal;

[0050] 3) The standby power supply automatic switching device 24 is normally put into operation, and the diesel generator 21 is in the cold standby state;

[0051] 4) When frequency modulation is required when the gas turbine system oscillates, the gas turbine TCS system 23 issues a frequency modulation command to the gas turbine system for adjustment to adjust the output of the gas turbine generator 11 for frequency modulation;

[0052] 5) When the coal-fired unit trips off the grid due to the oscillation of the gas turbine system, the zero-power generator tripping protection of the coal-fired generator 1 operates to trip the main transformer high-voltage side circuit breaker 3 and the plant incoming line circuit breaker 7;

[0053] 6) When the gas turbine TCS system 23 receives the command to enter the FCB mode, it adjusts the output of the gas turbine system according to the load sizes of the coal-fired unit plant auxiliary equipment and other loads 5 and the gas turbine plant auxiliary equipment and other loads 6;

[0054] 7) After the gas turbine system enters the FCB mode, when the gas turbine generator 11 can maintain the stable operation of the coal-fired unit plant auxiliary equipment and other loads 5 and the gas turbine plant auxiliary equipment and other loads 6, it proceeds to step 8), otherwise, it proceeds to step 9);

[0055] 8) After the gas turbine generator 11 operates stably, the coal-fired unit is restarted. After the coal-fired generator 1 rebuilds voltage, the plant incoming line circuit breaker 7 is closed using the synchronization device 22, and at the same time, the main transformer high-voltage side circuit breaker 3 is closed to charge the line, and the gas turbine generator 11 serves as the black start power source;

[0056] 9) The gas turbine generator 11 trips and the gas turbine generator outlet circuit breaker 13 is tripped, the 6kV bus section 10 of the plant loses voltage, and the coal-fired unit plant load circuit breaker 8 and the gas turbine plant load circuit breaker 9 are tripped;

[0057] 10) The automatic bus transfer device 24 issues an instruction to start and build voltage for the diesel generator 21. After the diesel generator 21 successfully builds voltage, the outlet circuit breaker 20 of the diesel generator is automatically closed. The automatic bus transfer device 24 trips the incoming circuit breaker 17 of the security MCC section and closes the incoming circuit breaker 19 of the diesel generator. The security MCC section bus 18 is powered by the diesel generator 21.

[0058] 11) After there is no abnormality in the security MCC section bus 18, the incoming circuit breaker 17 of the security MCC section is closed. The security PC section bus 15 is powered by the diesel generator 21. After there is no abnormality in the security PC section bus 15, the incoming circuit breaker 12 of the security PC section is closed. The 6 kV bus section 10 of the power plant is powered by the diesel generator 21.

[0059] 12) The gas turbine plant load circuit breaker 9 is closed to sequentially turn on the auxiliary equipment and other loads 6 of the gas turbine plant. Then, the gas turbine generator 11 is started. After the gas turbine generator 11 builds voltage, the outlet circuit breaker 13 of the gas turbine generator is closed, and the 6 kV bus section 10 of the power plant is powered by the gas turbine generator 11.

[0060] 13) The incoming circuit breaker 19 of the diesel generator and the outlet circuit breaker 20 of the diesel generator are disconnected, and the diesel generator 21 withdraws.

[0061] 14) The coal-fired unit plant load circuit breaker 8 is closed to sequentially turn on the auxiliary equipment and other loads 5 of the coal-fired unit. Then, the gas turbine generator 11 is started. After the coal-fired generator 1 builds voltage, the incoming circuit breaker 7 is closed by using the synchronization device 22.

[0062] 15) After the operating parameters of the coal-fired generator 1 are normal, the main transformer high-voltage side circuit breaker 3 is closed to charge the line, and the coal-fired generator 1 serves as the black start power source.

[0063] The advantage of the present invention is that generally there is a lack of hydropower stations and large gas turbine units in the northern region. However, as a power source point support, a certain black start power source is required. Small new energy power stations have limited leading-in phase capacity due to their relatively low connected voltage levels, and generally have a small capacity. Therefore, they do not have obvious advantages as black start power sources. While a thermal power plant combined with a small gas turbine with FCB function has the characteristics of large capacity, high connected voltage level, fast hot start, and certain leading-in phase capacity, and is very suitable as a black start power source in the northern region lacking hydropower and large gas turbine units.

[0064] In the past, when using coal-fired units as black start power sources, large diesel generator sets needed to be used in parallel for power supply as the start power source, resulting in a large investment. Moreover, during the normal operation of the unit, the idle rate of the diesel generator 21 is relatively high, and the investment return ratio is very poor.

[0065] The control system of the small gas turbine is precise, making it relatively easy to achieve FCB. It has a short startup time, a low idle rate of power supply assets for the auxiliary power system of the coal-fired unit. It can not only reduce the auxiliary power rate, but also add the system frequency modulation function, and has a low investment cost and a short construction period.

[0066] After the gas turbine successfully enters the FCB mode, it can effectively ensure that the auxiliary power is not lost. The coal-fired unit can quickly restore the system in a short time under hot conditions. Even if the FCB mode fails, the gas turbine system can be quickly restarted by using the configured diesel generator 21 as the power supply to restore the auxiliary power.

[0067] At the same time, a synchronization device 22 is set to avoid the risk of non-synchronous closing when restoring the auxiliary power.

[0068] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A black start method for a thermal power plant integrating a small gas turbine with FCB function, characterized in that, A black start system for a thermal power plant integrating a small gas turbine with FCB function, the black start system for the thermal power plant integrating a small gas turbine with FCB function includes a coal-fired generator (1), a main transformer (2), a station service transformer (4), coal-fired unit station service auxiliary equipment and other loads (5), gas turbine station service auxiliary equipment and other loads (6), a station service incoming breaker (7), a 6kV station service bus section (10), a gas turbine system, a security transformer (14), a security PC section bus (15), a security MCC section feeder breaker (16), a security MCC section incoming breaker (17), a security MCC section bus (18), a diesel generator incoming breaker (19), a diesel generator (21), a synchronization device (22), a gas turbine TCS system (23) and an automatic bus transfer device (24), and the gas turbine system includes a gas turbine generator (11) and a gas turbine generator outlet breaker (13); The machine end of the coal-fired generator (1) is respectively connected to one side of the main transformer (2) and one side of the station service transformer (4), the other side of the main transformer (2) is connected to the power grid system, and the other side of the station service transformer (4) is connected to the 6kV station service bus section (10) through the station service incoming breaker (7); the gas turbine generator (11) is connected to the 6kV station service bus section (10) through the gas turbine generator outlet breaker (13), the coal-fired unit station service auxiliary equipment and other loads (5) are connected to the 6kV station service bus section (10), the gas turbine station service auxiliary equipment and other loads (6) are connected to the 6kV station service bus section (10), and the 6kV station service bus section (10) is connected to the security PC section bus (15) through the security transformer (14); The security PC section bus (15) is connected to the security MCC section bus (18) through the security MCC section feeder breaker (16) and the security MCC section incoming breaker (17); the diesel generator (21) is connected to the power supply to the security MCC section bus (18) through the diesel generator incoming breaker (19); The synchronization device (22) is connected to the station service incoming breaker (7) and the 6kV station service bus section (10); the gas turbine TCS system (23) is connected to the gas turbine system; the automatic bus transfer device (24) is connected to the security MCC section incoming breaker (17) and the diesel generator incoming breaker (19); The main transformer (2) is connected to the power grid system through the main transformer high-voltage side breaker (3); The 6kV station service bus section (10) is connected to the security PC section bus (15) through the security PC section incoming breaker (12) and the security transformer (14); The diesel generator (21) is connected to the power supply to the security MCC section bus (18) through the diesel generator outlet breaker (20) and the diesel generator incoming breaker (19); The coal-fired unit station service auxiliary equipment and other loads (5) are connected to the 6kV station service bus section (10) through the coal-fired unit station service load breaker (8); The gas turbine station service auxiliary equipment and other loads (6) are connected to the 6kV station service bus section (10) through the gas turbine station service load breaker (9); Including the following steps: 1) When the unit is operating normally, the coal-fired generator (1) is connected to the grid for power generation. The main transformer high-voltage side circuit breaker (3) is in the closed position, the plant service incoming line circuit breaker (7) is in the closed position, the coal-fired unit plant service load circuit breaker (8) is in the closed position, the gas turbine plant service load circuit breaker (9) is in the closed position, the gas turbine generator outlet circuit breaker (13) is in the closed position, and the 6kV bus section of the plant service (10) is powered jointly by the plant service transformer (4) and the gas turbine generator (11). 2) The emergency power supply PC section incoming line circuit breaker (12) is in the closed position, the emergency power supply MCC section feeder circuit breaker (16) is in the closed position, the emergency power supply MCC section incoming line circuit breaker (17) is in the closed position, the diesel generator incoming line circuit breaker (19) is in the open position, the diesel generator outlet circuit breaker (20) is in the open position, and the voltages of the emergency power supply PC section bus (15) and the emergency power supply MCC section bus (18) are normal. 3) The automatic standby power supply device (24) is normally put into operation, and the diesel generator (21) is in the cold standby state. 4) When frequency modulation is required during the oscillation of the gas turbine system, the gas turbine TCS system (23) issues a frequency modulation command to adjust the output of the gas turbine generator (11) for frequency modulation. 5) When the oscillation of the gas turbine system causes the coal-fired unit to be disconnected from the grid, the zero-power generator tripping protection of the coal-fired generator (1) operates, and the main transformer high-voltage side circuit breaker (3) and the plant service incoming line circuit breaker (7) are tripped. 6) After the gas turbine TCS system (23) receives the instruction to enter the FCB mode, it adjusts the output of the gas turbine system according to the load sizes of the coal-fired unit plant service auxiliary equipment and other loads (5) and the gas turbine plant service auxiliary equipment and other loads (6). 7) After the gas turbine system enters the FCB mode, when the gas turbine generator (11) can maintain the stable operation of the coal-fired unit plant service auxiliary equipment and other loads (5) and the gas turbine plant service auxiliary equipment and other loads (6), it proceeds to step 8), otherwise, it proceeds to step 9). 8) After the gas turbine generator (11) operates stably, the coal-fired unit is restarted. After the coal-fired generator (1) rebuilds voltage, the plant service incoming line circuit breaker (7) is closed using the synchronization device (22), and at the same time, the main transformer high-voltage side circuit breaker (3) is closed to charge the line. The gas turbine generator (11) serves as the black start power source. 9) The gas turbine generator (11) trips and the gas turbine generator outlet circuit breaker (13) is tripped. The 6kV bus section of the plant service (10) loses voltage, and the coal-fired unit plant service load circuit breaker (8) and the gas turbine plant service load circuit breaker (9) are tripped. 10) The automatic standby power supply device (24) issues an instruction to start and build voltage for the diesel generator (21). After the diesel generator (21) builds voltage successfully, the diesel generator outlet circuit breaker (20) is automatically closed. The automatic standby power supply device (24) trips the emergency power supply MCC section incoming line circuit breaker (17) and closes the diesel generator incoming line circuit breaker (19). The emergency power supply MCC section bus (18) is powered by the diesel generator (21). 11) After there is no abnormality in the security MCC section busbar (18), close the incoming breaker (17) of the security MCC section. The security PC section busbar (15) is powered by the diesel generator (21). After there is no abnormality in the security PC section busbar (15), close the incoming breaker (12) of the security PC section. The 6 kV plant busbar section (10) is powered by the diesel generator (21); 12) Close the breaker (9) of the gas turbine plant load. Sequentially start the auxiliary equipment and other loads (6) of the gas turbine plant, and then start the gas turbine generator (11). After the gas turbine generator (11) builds up voltage, close the outlet breaker (13) of the gas turbine generator. The gas turbine generator (11) supplies power to the 6 kV plant busbar section (10); 13) Open the incoming breaker (19) and the outlet breaker (20) of the diesel generator. The diesel generator (21) is taken out of service; 14) Close the breaker (8) of the coal-fired unit plant load. Sequentially start the auxiliary equipment and other loads (5) of the coal-fired unit plant, and then start the gas turbine generator (11). After the coal-fired generator (1) builds up voltage, use the synchronization device (22) to close the incoming breaker (7) of the plant; 15) After the operating parameters of the coal-fired generator (1) are normal, close the breaker (3) on the high-voltage side of the main transformer to charge the line. The coal-fired generator (1) serves as the black start power source.

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