A grid-constructing photovoltaic and photo-thermal power station combined black start system and method

Abstract

The application discloses a grid-connected photovoltaic and photo-thermal power station combined black-start system and method, and relates to the field of power station black-start systems.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic and solar thermal power generation technology, and in particular to a combined black-start system and method for grid-connected photovoltaic and solar thermal power plants. Background Technology

[0002] Northwest my country boasts abundant solar energy resources, making it suitable for the large-scale application of photovoltaic (PV) and concentrated solar power (CSP) technologies. As the proportion of power electronic equipment in power systems continues to increase, grid-connected PV systems will play a crucial role in providing excellent voltage support in areas with weak power grids. CSP plants, on the other hand, offer advantages such as rotational inertia support, long-term energy storage, and zero-carbon green electricity. They also possess the ability to absorb curtailed PV power and couple with natural gas, making them a potential "ballast" for system stability. Currently, PV + CSP new energy bases have entered a large-scale development phase and will occupy an important position in the new power system. However, research on combined PV + CSP black-start technology is still in its infancy. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a combined black-start system and method for grid-connected photovoltaic and solar thermal power plants.

[0004] This invention is achieved through the following technical solution: In a first aspect, a grid-type photovoltaic and solar thermal power plant combined black-start system includes a generator module, a turbine module, a high-voltage bus module, a 35kV subsystem, and a black-start photovoltaic power generation unit; the generator module is electrically connected to the high-voltage bus module; the high-voltage bus module is electrically connected to the 35kV subsystem; the black-start photovoltaic power generation unit is installed on the 35kV subsystem, and the turbine module is mechanically connected to the generator module's generator via a turbine.

[0005] Specifically, the generator module also includes a generator outlet circuit breaker with one end electrically connected to the generator and the other end electrically connected to the low-voltage side of the No. 1 main transformer, the high-voltage side of the excitation transformer, and the high-voltage side of the plant high-voltage transformer; the low-voltage side of the excitation transformer is electrically connected to one end of the AC side isolator of the excitation system, and the other end of the AC side isolator of the excitation system is electrically connected to the excitation system; the low-voltage side of the plant high-voltage transformer is electrically connected to one end of the low-voltage side circuit breaker of the plant high-voltage transformer; the high-voltage side of the No. 1 main transformer is electrically connected to one end of the high-voltage side circuit breaker of the No. 1 main transformer, and the other end of the high-voltage side circuit breaker of the No. 1 main transformer is electrically connected to one end of the high-voltage busbar module.

[0006] Specifically, the high-voltage busbar module also includes a grid-connected circuit breaker with one end connected to the high-voltage busbar and the other end connected to the external power grid. The high-voltage busbar is also electrically connected to the high-voltage side circuit breaker of the No. 2 main transformer of the 35kV subsystem.

[0007] Specifically, the 35kV subsystem also includes a No. 2 main transformer whose high-voltage side is electrically connected to the high-voltage side circuit breaker of the No. 2 main transformer, whose low-voltage side is electrically connected to one end of the 35kV outlet circuit breaker, and whose other end is electrically connected to the 35kV busbar. Multiple collector lines are also connected to the 35kV busbar, and each collector line is electrically connected to the 35kV busbar through a corresponding collector line circuit breaker. Multiple photovoltaic power generation units are connected in parallel on each collector line.

[0008] Specifically, the black-start photovoltaic power generation unit is installed on the 35kV subsystem zero collector line and includes a grid-type inverter, a low-voltage side circuit breaker of the box-type transformer, a box-type transformer, a load switch, and also includes a unique starting power supply and a starting power supply circuit breaker. The starting power supply is electrically connected to the control system of the grid-type inverter through the starting power supply circuit breaker. The starting power supply is a diesel generator or a UPS.

[0009] Specifically, the turbine module further includes: a turbine whose inlet end is connected to the steam generator outlet end and whose outlet end is connected to the condenser inlet end; the condenser outlet end is connected to the feedwater pump inlet end and the feedwater pump outlet end is connected to the steam generator inlet end; the high-temperature heat storage tank input end is connected to the mirror field high-temperature medium output end and the output end is connected to the high-temperature medium pump input end; the steam generator high-temperature medium input end is connected to the high-temperature medium pump output end and the output end is connected to the low-temperature heat storage tank input end; the low-temperature medium pump input end is connected to the low-temperature heat storage tank output end and the output end is connected to the mirror field low-temperature medium input end.

[0010] On the other hand, a combined black start method for grid-connected photovoltaic and solar thermal power plants, based on a combined black start system for grid-connected photovoltaic and solar thermal power plants, includes the following steps: Step S1: Before the combined black start of the grid-connected photovoltaic and solar thermal power plant, the grid-connected circuit breaker, the high-voltage side circuit breaker of the No. 1 main transformer, the high-voltage side circuit breaker of the No. 2 main transformer, the low-voltage side circuit breaker of the plant high-voltage transformer, the AC side isolator of the excitation system, the 35kV outlet circuit breaker, the collector line circuit breaker, the low-voltage side circuit breaker of the box-type substation, the load switch, and the starting power supply circuit breaker are all in the open state, and the entire system is in a state of power failure during the daytime. Step S2: Start-up of the black-start photovoltaic power generation unit; Step S3: Black start of the photovoltaic power generation system; Step S4: High-voltage busbar charging: Close the 35kV outlet circuit breaker to charge the No. 2 main transformer; close the No. 2 main transformer high-voltage side circuit breaker to charge the high-voltage busbar. Step S5: The power supply for the solar thermal power plant is energized; Step S6: Start-up of the solar thermal power plant: Start the high-temperature medium pump and the low-temperature medium pump. The low-temperature medium enters the mirror field from the low-temperature heat storage tank. Start the mirror field heat collection system. After the medium is heated, it enters the high-temperature heat storage tank. Start the feedwater pump. The high-temperature medium enters the steam generator from the high-temperature heat storage tank. After heat exchange, it becomes the low-temperature medium and enters the low-temperature medium tank. The steam generator generates high-temperature steam to drive the turbine rotor to increase its speed to 3000 r / min. Step S7: Synchronization process within the station: The generator excitation system is activated, the generator terminal voltage rises to the rated value, and after the generator output voltage and the low-voltage side voltage of the main transformer are synchronized, the generator output circuit breaker is closed, and the solar thermal power plant and photovoltaic power plant achieve synchronization. Step S8: External power grid charging, merge the grid circuit breaker to realize external power grid charging.

[0011] Furthermore, step S2 also includes the following sub-steps: Step S21: Activate the starting power supply of the black-start photovoltaic power generation unit, close the starting power circuit breaker, and the photovoltaic inverter starts and enters the no-load operation state; Step S22: Close the low-voltage side circuit breaker of the box-type transformer and charge the box-type transformer; Step S23: Close the load switch and charge the zero collector line.

[0012] Furthermore, according to claim 7, the method for combined black start of a grid-type photovoltaic and solar thermal power plant is characterized in that step S3 further includes the following sub-steps: Step S31: Each photovoltaic power generation unit on the zero collector line is started in sequence: first close the load switch, then close the low-voltage side circuit breaker of the transformer substation, so that the grid-type converter is energized and enters the working state; Step S32: Close the zero-number collector circuit breaker to charge the 35kV busbar; Step S33: Sequentially put each photovoltaic power generation unit on each set of collector lines into working state: close the corresponding collector line circuit breaker, charge the collector line, and then sequentially put the photovoltaic power generation units on the collector lines into working state; after all the photovoltaic power generation units on a collector line are in working state, start the photovoltaic power generation units on the next collector line.

[0013] Furthermore, step S5 also includes the following sub-steps: Step S51: Combine the high-voltage side circuit breaker of the No. 1 main transformer, and charge the No. 1 main transformer, excitation transformer and plant high-voltage transformer. Step S52: The AC side deflector of the excitation system is switched on, and the excitation system is energized; Step S53: Connect the low-voltage side circuit breaker of the plant's high-voltage transformer and energize the plant's auxiliary load.

[0014] The beneficial effects of this invention are as follows: This invention proposes a combined black-start system and method for grid-type photovoltaic and solar thermal power plants. It constructs a combined black-start system for grid-type photovoltaic and solar thermal power plants, including a generator module, a turbine module, a high-voltage bus module, a 35kV subsystem, and a black-start photovoltaic power generation unit. It fully utilizes the voltage support capability of grid-type photovoltaics and the energy storage capability of solar thermal power plants to achieve black-start in areas with 100% renewable energy power. After successful black-start, it has the ability to generate electricity at night. It is applicable to tower, trough, and linear Fresnel solar thermal power plants. Attached Figure Description

[0015] Figure 1 This is a diagram of a grid-type photovoltaic and solar thermal power plant combined black start system architecture proposed in this invention; Among them, 1-generator, 11-generator outlet circuit breaker, 12-plant high-voltage transformer, 121-plant high-voltage transformer low-voltage side circuit breaker, 13-plant auxiliary load, 14-excitation transformer, 15-excitation system AC side disconnector, 16-excitation system, 17-No. 1 main transformer, 18-No. 1 main transformer high-voltage side circuit breaker, 2-steam turbine, 21-condenser, 22-feed water pump, 23-steam generator, 24-low temperature thermal storage tank, 25-low temperature medium pump, 26-mirror field, 27-high temperature thermal storage tank, 28-high temperature medium pump, 3-high voltage busbar, 31-grid-connected circuit breaker, 4-35kV busbar Line, 41-No. 2 main transformer, 42-35kV outlet circuit breaker, 43-No. 2 main transformer high-voltage side circuit breaker, 44-No. 0 collector line circuit breaker, 441-No. 1 collector line circuit breaker, 442-No. 2 collector line circuit breaker, 45-No. 0 collector line, 451-No. 1 collector line, 452-No. 2 collector line, 05-Black start photovoltaic power generation unit, 5-Grid-type inverter, 51-Box substation low-voltage side circuit breaker, 52-Box-type transformer, 53-Load switch, 54-Starting power supply circuit breaker, 55-Starting power supply, 56-Photovoltaic array, 6-External power grid. Detailed Implementation

[0016] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0017] This invention proposes a combined black start system and method for grid-connected photovoltaic and solar thermal power plants, which can fully utilize the voltage support capability of grid-connected photovoltaics and the long-term energy storage capability of solar thermal power plants to achieve grid black start.

[0018] This invention constructs a combined black-start system for grid-connected photovoltaic and solar thermal power plants, such as... Figure 1As shown, the system includes generator 1, generator outlet circuit breaker 11, plant high-voltage transformer 12, plant high-voltage transformer low-voltage side circuit breaker 121, plant auxiliary load 13, excitation transformer 14, excitation system AC side isolator 15, excitation system 16, No. 1 main transformer 17, No. 1 main transformer high-voltage side circuit breaker 18, steam turbine 2, condenser 21, feedwater pump 22, steam generator 23, cryogenic thermal storage tank 24, cryogenic medium pump 25, mirror field 26, high-temperature thermal storage tank 27, high-temperature medium pump 28, high-voltage busbar 3, grid-connected circuit breaker 31, and 35kV busbar 4. 41. Main Transformer No. 2, 42. 35kV Outlet Circuit Breaker, 43. High Voltage Side Circuit Breaker of Main Transformer No. 2, 44. Zero Collector Line Circuit Breaker, 441. One Collector Line Circuit Breaker, 442. Zero Collector Line, 451. One Collector Line, 452. Black Start Photovoltaic Power Generation Unit, 5. Grid-type Inverter, 52. Low Voltage Side Circuit Breaker of Box-type Substation, 52. Box-type Transformer, 53. Load Switch, 54. Starting Power Supply Circuit Breaker, 55. Starting Power Supply, 56. Photovoltaic Array, 6. External Power Grid.

[0019] In this embodiment, generator 1 is electrically connected to one end of generator outlet circuit breaker 11, and the other end of generator outlet circuit breaker 11 is electrically connected to the low-voltage side of main transformer 17, the high-voltage side of excitation transformer 14, and the high-voltage side of plant high-voltage transformer 12. The low-voltage side of excitation transformer 14 is electrically connected to one end of AC side isolator 15 of excitation system, and the other end of AC side isolator 15 of excitation system is electrically connected to excitation system 16. The low-voltage side of plant high-voltage transformer 12 is electrically connected to one end of low-voltage side circuit breaker 121 of plant high-voltage transformer. The high-voltage side of main transformer 17 is electrically connected to one end of high-voltage side circuit breaker 18 of main transformer 17, and the other end of high-voltage side circuit breaker 18 of main transformer 17 is electrically connected to high-voltage busbar 3. High-voltage busbar 3 is electrically connected to one end of grid-connected circuit breaker 31, and the other end of grid-connected circuit breaker 31 is electrically connected to external power grid 6. High-voltage busbar 3 is electrically connected to one end of high-voltage side circuit breaker 43 of main transformer No. 2. The other end of high-voltage side circuit breaker 43 of main transformer No. 2 is electrically connected to the high-voltage side of main transformer No. 2. The low-voltage side of main transformer No. 2 is electrically connected to one end of 35kV outlet circuit breaker 42. The other end of 35kV outlet circuit breaker 42 is electrically connected to 35kV busbar 4. Zero collector line 45, No. 1 collector line 451 and No. 2 collector line 452 are connected to 35kV busbar 4. Zero collector line 45, No. 1 collector line 451 and No. 2 collector line 452 are electrically connected to 35kV busbar 4 through zero collector line circuit breaker 44, No. 1 collector line circuit breaker 441 and No. 2 collector line circuit breaker 442 respectively. Multiple sets of photovoltaic power generation units are connected in parallel on each collector line. Specifically, the black-start photovoltaic power generation unit 05 on the zero-line collector 451 has a special structure. In addition to the grid-type inverter 5, low-voltage side circuit breaker 51, box-type transformer 52, and load switch included in a typical photovoltaic power generation unit, it also includes a unique starting power supply 55 and starting power supply circuit breaker 54. The starting power supply 55 is electrically connected to the control system of the grid-type inverter 5 via the starting power supply circuit breaker 43. The starting power supply uses a diesel generator.

[0020] Generator 1 is mechanically connected to turbine 2 on the same shaft. The inlet of turbine 2 is connected to the outlet of steam generator 23. The outlet of turbine 2 is connected to the inlet of condenser 21. The outlet of condenser 21 is connected to the inlet of feedwater pump 22. The outlet of feedwater pump 22 is connected to the inlet of steam generator 23. The high-temperature medium output of mirror field 26 is connected to the input of high-temperature heat storage tank 27. The output of high-temperature heat storage tank 27 is connected to the input of high-temperature medium pump 28. The output of high-temperature medium pump 28 is connected to the high-temperature medium input of steam generator 23. The low-temperature medium output of steam generator 23 is connected to the input of low-temperature heat storage tank 24. The output of low-temperature heat storage tank 24 is connected to the input of low-temperature medium pump 25. The output of low-temperature medium pump 25 is connected to the low-temperature medium input of mirror field 26.

[0021] In this embodiment, a combined black start method for grid-connected photovoltaic and solar thermal power plants includes the following steps: Before the combined black start of the S1. grid-connected photovoltaic and solar thermal power plant, the following circuit breakers are in the open state: grid-connected circuit breaker 31, high-voltage side circuit breaker 18 of main transformer 1, high-voltage side circuit breaker 43 of main transformer 2, low-voltage side circuit breaker 121 of plant high-voltage transformer, AC side isolator 15 of excitation system, 35kV outlet circuit breaker 42, zero collector line circuit breaker 44, first collector line circuit breaker 441, second collector line circuit breaker 442, low-voltage side circuit breaker 51 of transformer substation, load switch 53, and starting power supply circuit breaker 54. The entire system is in a state of power failure during the daytime.

[0022] S2. Black Start Photovoltaic Power Generation Unit 05 Start: 1) Activate the starting power supply 55 of the black start photovoltaic power generation unit 05, close the starting power circuit breaker 54, and the photovoltaic inverter 5 starts and enters the no-load operation state.

[0023] 2) Connect the low-voltage side circuit breaker 51 of the box-type transformer and charge the box-type transformer 52.

[0024] 3) Connect load switch 53 and charge the zero collector line 45.

[0025] S3. Black start of photovoltaic power generation system: 1) The photovoltaic power generation units on the zero-number collector line 45 are started in sequence. The process is as follows: first close the load switch, then close the low-voltage side circuit breaker of the transformer substation, so that the grid-type converter is energized and enters the working state.

[0026] 2) Close the zero-number collector circuit breaker 44 to charge the 35kV bus 4.

[0027] 3) The photovoltaic power generation units on each collector line are sequentially brought into operation. The process is as follows: the corresponding collector line circuit breaker is closed, the collector line is charged, and then the photovoltaic power generation units on the collector lines are sequentially brought into operation. After all photovoltaic power generation units on one collector line are in operation, the photovoltaic power generation units on the next collector line are started. Subsequently, the circuit breakers 441 and 442 of collector line 1 are closed, and all photovoltaic power generation units are in operation.

[0028] S4. High voltage bus 3 charging.

[0029] 1) Charge the 35kV output circuit breaker 42 and the No. 2 main transformer 41.

[0030] 2) The high-voltage side circuit breaker 43 of the No. 2 main transformer is charged, and the high-voltage bus 3 is charged.

[0031] 1) Charge the high-voltage side circuit breaker 18 of the main transformer No. 1, the main transformer No. 17, the excitation transformer 14 and the high-voltage transformer 12 of the plant.

[0032] 2) The AC side isolator 15 of the combined excitation system and the excitation system 16 are energized.

[0033] 3) The low-voltage side circuit breaker 121 of the combined plant high-voltage transformer is energized, and the plant load 13 is energized.

[0034] S6. Start-up of the solar thermal power plant: 1) Start the high-temperature medium pump 28 and the low-temperature medium pump 25. The low-temperature medium enters the mirror field 26 from the low-temperature heat storage tank 24. Start the heat collection system of the mirror field 26. After the medium is heated, it enters the high-temperature heat storage tank 27.

[0035] 2) Start the feedwater pump 22. The high-temperature medium enters the steam generator 23 from the high-temperature heat storage tank 27. After heat exchange, it becomes a low-temperature medium and enters the low-temperature medium tank 24. The steam generator 23 generates high-temperature steam to drive the rotor of the steam turbine 2 to increase the speed to 3000 r / min.

[0036] S7. Synchronous process within the station.

[0037] 1) The generator excitation system 16 is activated, and the terminal voltage of generator 1 rises to the rated value.

[0038] 2) After the output voltage of generator 1 and the low-voltage side voltage of the main transformer are synchronized, the generator output circuit breaker 11 is closed, and the solar thermal power plant and the photovoltaic power plant achieve synchronization.

[0039] S8. External power grid 6 is charged, and the combined grid circuit breaker 31 is used to realize the charging of external power grid 6.

[0040] In one embodiment, to further reduce the black start time, after completing step S2. Black start photovoltaic power generation unit 05 start-up, in step S3. Photovoltaic power generation system black start-up: When the photovoltaic power generation units in each collector line are started up gradually, if the total output power of the photovoltaic power generation units P ≥ μP0, the process can directly proceed to step S4, charging the high-voltage bus 3. In subsequent steps, other photovoltaic power generation units will be started up simultaneously. P0 is the starting power of the solar thermal power plant after considering the charging of the bus and transformer and the operation of the plant auxiliary load, and μ is the output margin considering the fluctuation of solar irradiance and the starting current of the plant auxiliary load.

[0041] This invention proposes a combined black-start system and method for grid-connected photovoltaic (PV) and solar thermal power plants. The combined black-start system includes a generator module, a turbine module, a high-voltage busbar module, a 35kV subsystem, and a black-start PV power generation unit. By constructing this combined black-start system, the voltage support capability of the grid-connected PV system and the long-term energy storage capability of the solar thermal power plant are fully utilized to achieve black-start in areas with 100% renewable energy power supply. After successful black-start, the system provides nighttime power generation capability and is applicable to tower, trough, and linear Fresnel solar thermal power plants.

[0042] The foregoing description and illustrations have shown and described the basic principles, main features, and advantages of this invention. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A combined black-start system for grid-connected photovoltaic and solar thermal power plants, characterized in that, It includes a generator module, a steam turbine module, a high-voltage bus module, a 35kV subsystem, and a black-start photovoltaic power generation unit (05); the generator module is electrically connected to the high-voltage bus module; the high-voltage bus module is electrically connected to the 35kV subsystem; the black-start photovoltaic power generation unit (05) is installed on the 35kV subsystem; the steam turbine module is mechanically connected to the generator module generator (1) on the same axis through a steam turbine (2); The generator module also includes a generator outlet circuit breaker (11) with one end electrically connected to the generator (1) and the other end electrically connected to the low-voltage side of the No. 1 main transformer (17), the high-voltage side of the excitation transformer (14), and the high-voltage side of the plant high-voltage transformer (12); the high-voltage side of the No. 1 main transformer (17) is electrically connected to one end of the high-voltage side circuit breaker (18) of the No. 1 main transformer, and the other end of the high-voltage side circuit breaker (18) of the No. 1 main transformer is electrically connected to one end of the high-voltage busbar (3) of the high-voltage busbar module; the low-voltage side of the excitation transformer (14) is electrically connected to one end of the AC side isolator (15) of the excitation system, and the other end of the AC side isolator (15) of the excitation system is electrically connected to the excitation system (16); The high-voltage bus module also includes a grid-connected circuit breaker (31) with one end connected to the high-voltage bus (3) and the other end connected to the external power grid (6). The high-voltage side of the 35kV subsystem is electrically connected to the high-voltage side circuit breaker (43) of the No. 2 main transformer, and the low-voltage side is electrically connected to the No. 2 main transformer (41) at one end of the 35kV outlet circuit breaker (42). The other end of the 35kV outlet circuit breaker (42) is electrically connected to the 35kV bus (4). The system-based joint black start method for grid-connected photovoltaic and solar thermal power plants includes the following steps: Step S1: Before the combined black start of the grid-connected photovoltaic and solar thermal power plants, the entire system is in a state of power failure during the daytime; Step S2: Start the black-start photovoltaic power generation unit (05); Step S3: Black start of the photovoltaic power generation system; Step S4: High-voltage busbar (3) charging: Close the 35kV outlet circuit breaker (42) and charge the No. 2 main transformer (41); Close the No. 2 main transformer high-voltage side circuit breaker (43) and charge the high-voltage busbar (3); Step S5: The power supply for the solar thermal power plant is energized; Step S6: Start-up of the solar thermal power plant; Step S7: Synchronization process within the station: The excitation system (16) of the generator is activated, the generator terminal voltage rises to the rated value, and after the generator output voltage and the low-voltage side voltage of the main transformer are synchronized, the generator output circuit breaker (11) is closed, and the solar thermal power plant and the photovoltaic power plant achieve synchronization. Step S8: External power grid charging, merge the grid circuit breaker (31) to realize external power grid charging.

2. The combined black-start system for grid-type photovoltaic and solar thermal power plants according to claim 1, characterized in that, The low-voltage side of the high-voltage transformer (12) is electrically connected to one end of the low-voltage side circuit breaker (121) of the high-voltage transformer.

3. The combined black-start system for grid-type photovoltaic and solar thermal power plants according to claim 1, characterized in that, The high-voltage busbar (3) is also electrically connected to the high-voltage side circuit breaker (43) of the No. 2 main transformer of the 35kV subsystem.

4. A combined black-start system for grid-connected photovoltaic and solar thermal power plants according to claim 1, characterized in that, The 35kV bus (4) is also connected to multiple collector lines (45, 451, 452). The collector lines (45, 451, 452) are electrically connected to the 35kV bus (4) through corresponding collector line circuit breakers (44, 441, 442). Each collector line is connected in parallel to multiple photovoltaic power generation units.

5. A combined black-start system for grid-type photovoltaic and solar thermal power plants according to claim 4, characterized in that, The black-start photovoltaic power generation unit (05) is installed on the zero collection line (45) of the 35kV subsystem and includes a grid-type inverter (5), a low-voltage side circuit breaker (51) of the box transformer, a box transformer (52), a load switch (53), and also includes a unique starting power supply (55) and a starting power supply circuit breaker (54). The starting power supply (55) is electrically connected to the control system of the grid-type inverter (5) through the starting power supply circuit breaker (43). The starting power supply (55) is a diesel generator or a UPS.

6. A combined black-start system for grid-connected photovoltaic and solar thermal power plants according to claim 5, characterized in that, The turbine module further includes: a turbine (2) whose inlet end is connected to the outlet end of the steam generator (23) and whose outlet end is connected to the inlet end of the condenser (21); the outlet end of the condenser (21) is connected to the inlet end of the feed water pump (22); the outlet end of the feed water pump (22) is connected to the inlet end of the steam generator (23); the input end of the high-temperature heat storage tank (27) is connected to the high-temperature medium output end of the mirror field (26); the output end is connected to the input end of the high-temperature medium pump (28); the high-temperature medium input end of the steam generator (23) is connected to the output end of the high-temperature medium pump (28); the output end is connected to the input end of the low-temperature heat storage tank (24); the input end of the low-temperature medium pump (25) is connected to the output end of the low-temperature heat storage tank (24); and the output end is connected to the low-temperature medium input end of the mirror field (26).

7. A combined black-start system for grid-connected photovoltaic and solar thermal power plants according to claim 6, characterized in that, In the system-based joint black start method for grid-connected photovoltaic and solar thermal power plants: Step S1, the entire system is in a state of power failure, specifically including: the grid-connected circuit breaker (31), the high-voltage side circuit breaker of the No. 1 main transformer (18), the high-voltage side circuit breaker of the No. 2 main transformer (43), the low-voltage side circuit breaker of the plant high-voltage transformer (121), the AC side disconnector of the excitation system (15), the 35kV outlet circuit breaker (42), the collector line circuit breaker (44, 441, 442), the low-voltage side circuit breaker of the box-type transformer (51), the load switch (53), and the starting power supply circuit breaker (54) are all in the open state; Step S6, the startup of the solar thermal power plant, specifically includes: starting the high-temperature medium pump and the low-temperature medium pump; the low-temperature medium enters the mirror field from the low-temperature heat storage tank; starting the mirror field heat collection system; the medium enters the high-temperature heat storage tank after being heated; starting the feedwater pump; the high-temperature medium enters the steam generator from the high-temperature heat storage tank; after heat exchange, it becomes the low-temperature medium and enters the low-temperature medium tank; the steam generator generates high-temperature steam to drive the turbine rotor to increase its speed to 3000 r / min.

8. A combined black-start system for grid-type photovoltaic and solar thermal power plants according to claim 7, characterized in that, Step S2 further includes the following sub-steps: Step S21: Activate the starting power supply of the black-start photovoltaic power generation unit, close the starting power circuit breaker, and the photovoltaic inverter starts and enters the no-load operation state; Step S22: Close the low-voltage side circuit breaker of the box-type transformer and charge the box-type transformer; Step S23: Close the load switch and charge the zero collector line.

9. A combined black-start system for grid-type photovoltaic and solar thermal power plants according to claim 7, characterized in that, Step S3 further includes the following sub-steps: Step S31: Each photovoltaic power generation unit on the zero collector line is started in sequence: first close the load switch, then close the low-voltage side circuit breaker of the transformer substation, so that the grid-type converter is energized and enters the working state; Step S32: Close the zero-number collector circuit breaker to charge the 35kV busbar; Step S33: Sequentially put each photovoltaic power generation unit on each set of collector lines into working state: close the corresponding collector line circuit breaker, charge the collector line, and then sequentially put the photovoltaic power generation units on the collector lines into working state; after all the photovoltaic power generation units on a collector line are in working state, start the photovoltaic power generation units on the next collector line.

10. A combined black-start system for grid-connected photovoltaic and solar thermal power plants according to claim 7, characterized in that, Step S5 further includes the following sub-steps: Step S51: Combine the high-voltage side circuit breaker of the No. 1 main transformer, and charge the No. 1 main transformer, excitation transformer and plant high-voltage transformer. Step S52: The AC side deflector of the excitation system is switched on, and the excitation system is energized; Step S53: Connect the low-voltage side circuit breaker of the plant's high-voltage transformer and energize the plant's auxiliary load.

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