Compressed air energy storage coupling phase modifier system and control method thereof

Abstract

The invention relates to the technical field of new energy stations, in particular to a compressed air energy storage coupling phase modifier system and a control method thereof.The system comprises a central control subsystem, a double-working-condition phase modifier system, a turbine subsystem, a compression subsystem, a cold and hot circulation subsystem and a gas storage; the control method comprises the steps that when a power grid has no primary frequency modulation requirement, the central control subsystem controls the first adjusting valve to be closed, and the double-working-condition phase modifier provides power to drive the turbine subsystem to be in an idling state; when the power grid needs primary frequency modulation or the power grid is in a large-range power loss state, the central control subsystem controls the first regulating valve to be opened, high-pressure gas stored in the gas storage is input into the turbine subsystem to expand and do work, and the turbine subsystem provides power to drive the dual-working-condition phase modifier to work in a power generation state. The method can provide support for stable operation of the power grid, can improve the anti-disturbance capability, and enables the new energy station to have the capability of actively supporting the power grid.

Description

Technical Field

[0001] This invention relates to the technical field of new energy power stations, and more specifically, to a system and control method for a compressed air energy storage coupled synchronous condenser. Background Technology

[0002] The current power system faces severe challenges due to the high proportion of renewable energy integration, including low system rotational inertia and weak rapid frequency regulation and voltage support capabilities. The "GB 38755-2019 Guidelines for the Safety and Stability of Power Systems" explicitly requires power sources to possess primary frequency regulation and rapid voltage regulation capabilities. The "GB / T 40595-2021 Technical Specifications and Test Guidelines for Primary Frequency Regulation of Grid-Connected Power Sources" further requires all grid-connected entities, including energy storage power stations, to possess rapid and effective primary frequency regulation functions. However, the electrochemical energy storage solutions commonly configured in current renewable energy power plants primarily achieve power charging and discharging regulation. While they can provide frequency response, they cannot offer the real rotational inertia necessary for supporting system transient stability, and they struggle to quickly switch to generation mode during grid faults, failing to meet the stringent requirements of the aforementioned national standards for response speed and support strength.

[0003] Currently, primary frequency regulation in the power system still relies mainly on traditional thermal and hydropower units, and their dynamic response characteristics still present a structural contradiction with the demand of a high proportion of renewable energy grids. Although new energy storage devices such as lithium batteries and supercapacitors have been attempted for frequency regulation assistance, their limited cycle life and performance degradation under high-frequency operation make it difficult to meet the grid's rigid requirements for the frequency and duration of primary frequency regulation operations. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing power systems in meeting the rigid requirements of the power grid for primary frequency regulation, and to provide a system and control method for compressed air energy storage coupled synchronous condensers, which can support the stable operation of the power grid, improve the anti-disturbance capability, and enable new energy power plants to actively support the power grid.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A compressed air energy storage coupled synchronous condenser system is provided, comprising a central control subsystem, a dual-condition synchronous condenser system, a turbine subsystem, and a compression subsystem; wherein, the dual-condition synchronous condenser system includes a dual-condition synchronous condenser and a synchronous condenser status signal sensor; the turbine subsystem is drively connected to the dual-condition synchronous condenser; the synchronous condenser status signal sensor detects the real-time operating parameters of the dual-condition synchronous condenser and inputs the detected signals to the signal input terminal of the central control subsystem, and the signal output terminal of the central control subsystem is electrically connected to the control terminals of the dual-condition synchronous condenser, the turbine subsystem, and the compression subsystem, respectively; and also includes a cooling system. The system includes a thermal cycle subsystem and a gas storage tank for storing high-pressure gas. The thermal cycle subsystem includes a heating unit for providing the heat required by the turbine side and a cooling unit for absorbing heat from the compression side. The gas pipeline of the cooling unit is connected to the compression subsystem, and the gas pipeline of the heating unit is connected to the turbine subsystem. The input end of the gas storage tank is connected to the cooling unit via a gas pipeline, and the output end of the gas storage tank is connected to the heating unit via a gas pipeline and a first regulating valve. The signal output end of the central control subsystem is electrically connected to the control end of the heating unit, the control end of the cooling unit, and the control end of the first regulating valve, respectively.

[0006] This invention discloses a compressed air energy storage coupled synchronous condenser system. The compression subsystem is configured to compress normal air to a high-pressure state. The turbine subsystem, the dual-condition synchronous condenser, and the drive connection between the turbine subsystem and the dual-condition synchronous condenser enable the dual-condition synchronous condenser to generate electricity using high-pressure gas stored in the gas storage tank during frequency regulation periods. Furthermore, during non-frequency regulation periods, the turbine subsystem can be driven by the dual-condition synchronous condenser. The thermal cycling subsystem provides the heat required by the turbine side and absorbs heat from the compression side. Through the coordinated control of these subsystems, this invention enables the system to possess voltage source characteristics, providing support for the stable operation of the power grid at different stages—before, during, and after disturbances—thus enhancing its anti-disturbance capability and enabling new energy power plants to actively support the power grid.

[0007] Preferably, the turbine subsystem includes a turbine unit and a vacuum pump connected to the turbine unit. The vacuum pump is equipped with a shut-off valve electrically connected to the central control subsystem. The dual-condition synchronous condenser is connected to the turbine unit through a transmission component, and the gas pipeline of the heating unit is connected to the turbine unit.

[0008] Preferably, the heating and cooling cycle subsystem further includes a heat storage unit and a cold storage unit, with the input and output ends of the water pipes of the heating unit connected to the heat storage unit and the cold storage unit, respectively, and the input and output ends of the water pipes of the cooling unit connected to the cold storage unit and the heat storage unit, respectively.

[0009] Preferably, the heating unit includes a heater group, the air inlet of the turbine unit is connected to the output of the gas storage tank through the air pipeline of the heater group, and the input and output ends of the water pipeline of the heater group are respectively connected to the heat storage unit and the cold storage unit.

[0010] Preferably, the compression subsystem includes a compressor unit, the cooling unit includes a cooler unit, the outlet of the compressor unit is connected to the input of the gas storage tank through the gas pipeline of the cooler unit, and the input and output of the water pipeline of the cooler unit are respectively connected to the cold storage unit and the heat storage unit.

[0011] Preferably, the cooling unit further includes a cooling tower assembly connected to the cooler assembly.

[0012] Preferably, the dual-condition synchronous condenser system further includes an excitation current regulator electrically connected to the dual-condition synchronous condenser.

[0013] Preferably, the hot and cold cycle subsystem is equipped with a flow sensor, a temperature sensor, a speed sensor, and a pressure sensor; the compression subsystem is equipped with a vibration sensor; the transmission end of the turbine subsystem and the compression subsystem are both equipped with speed sensors; and the signal input end of the central control subsystem is electrically connected to the control ends of the flow sensor, the temperature sensor, the speed sensor, the pressure sensor, and the vibration sensor, respectively.

[0014] The present invention also provides a control method for the above-mentioned system, comprising the following control process: When there is no primary frequency regulation requirement in the power grid, the central control subsystem controls the first regulating valve to close, the dual-condition synchronous condenser is in grid-connected state and supplies reactive power to the power grid, the dual-condition synchronous condenser provides power to drive the turbine subsystem to idle state, and at the same time, the synchronous condenser status signal sensor inputs the detected signal to the central control subsystem. When the power grid needs frequency regulation or when the power grid is in a state of large-scale power outage, the central control subsystem controls the first regulating valve to open, and the high-pressure gas stored in the gas storage tank is input into the turbine subsystem to expand and do work. The turbine subsystem provides power to drive the dual-condition synchronous condenser to work in the power generation state.

[0015] Preferably, when there is no primary frequency regulation requirement in the power grid, the central control subsystem controls the shut-off valve to open, and the turbine subsystem is in a negative pressure state. Compared with the prior art, the beneficial effects of the present invention are: This invention relates to a compressed air energy storage coupled synchronous condenser system and its control method. In the system, a compression subsystem is configured to compress normal air to a high-pressure state; a turbine subsystem, a dual-condition synchronous condenser, and a drive connection between the turbine subsystem and the dual-condition synchronous condenser are configured to use high-pressure gas stored in the gas storage tank to drive the dual-condition synchronous condenser to generate electricity during frequency regulation periods; and during non-frequency regulation periods, the dual-condition synchronous condenser can also drive the turbine subsystem; a thermal cycle subsystem is configured to provide the heat required by the turbine side and absorb heat from the compression side; in the control method, when there is no primary frequency regulation requirement in the power grid, the dual-condition synchronous condenser is in electric phase-shifting mode, and the turbine subsystem is driven by the dual-condition synchronous condenser. The system continuously provides rotational inertia to the power grid. When the power grid needs primary frequency regulation or is in a state of widespread power outage, the high-pressure gas stored in the gas storage facility can drive the turbine subsystem to provide power to drive the dual-condition synchronous condenser to generate electricity. At this time, the dual-condition synchronous condenser is in the power generation and phase regulation mode. This invention can improve the problem of insufficient primary frequency regulation support capability and inability to provide rotational inertia in new energy power generation projects. At the same time, the synchronous condenser has both phase regulation and power generation functions. Through the coordinated control of the above subsystems, this invention enables the system to have voltage source characteristics, and can provide support for the stable operation of the power grid in different stages before, during and after disturbances, thereby improving the anti-disturbance capability and enabling new energy power plants to actively support the power grid. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of each subsystem in the compressed air energy storage coupled synchronous condenser system of the present invention. The arrows in the figure indicate the flow direction of the streams. Figure 2 This is a schematic diagram of one embodiment of the compressed air energy storage coupled synchronous condenser system of the present invention. The arrows in the diagram indicate the flow direction of the streams. Figure 3 This is a schematic diagram of another embodiment of the compressed air energy storage coupled synchronous condenser system of the present invention. The arrows in the figure indicate the flow direction of the stream.

[0017] In the attached diagram: 110, Synchronous Condenser; 120, Excitation Current Regulator; 200, Turbine Subsystem; 210, First-Stage Turbine; 220, Second-Stage Turbine; 230, Third-Stage Turbine; 240, Vent Silencer; 250, First Transformer; 260, Vacuum Pump; 261, Shut-off Valve; 300, Compression Subsystem; 310, First-Stage Compressor; 320, Second-Stage Compressor; 330, Third-Stage Compressor; 340, Air Filter; 350, Second Transformer; 400, Heating Unit; 410, First-Stage Heater; 420, Second-Stage Heater; 430, Third-Stage Heater; 440, Third Regulating Valve; 500, Cooling Unit; 510, First-Stage Cooler; 520, Second-Stage Cooler; 530, Third-Stage Cooler; 540, Fourth-Stage Cooler; 550, Cooling Tower; 560, Second Regulating Valve; 570, Third Water Pump; 610. Thermal storage tank; 620. Cold storage tank; 630. First water pump; 640. Second water pump; 700. Gas storage tank; 710. First regulating valve; 720. Check valve; 800. Central control subsystem. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0019] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] Example 1 like Figures 1 to 2The diagram shows a first embodiment of a compressed air energy storage coupled synchronous condenser system according to the present invention, including a central control subsystem 800, a dual-condition synchronous condenser system, a turbine subsystem 200, and a compression subsystem 300; wherein, the dual-condition synchronous condenser system includes a dual-condition synchronous condenser 110 and a synchronous condenser status signal sensor D; the turbine subsystem 200 is drive-connected to the dual-condition synchronous condenser 110; the synchronous condenser status signal sensor D detects the real-time operating parameters of the dual-condition synchronous condenser 110 and inputs the detected signals to the signal input terminal of the central control subsystem 800, and the signal output terminal of the central control subsystem 800 is electrically connected to the control terminals of the dual-condition synchronous condenser 110, the turbine subsystem 200, and the compression subsystem 300, respectively; and... The system includes a heating and cooling cycle subsystem and a gas storage tank 700 for storing high-pressure gas. The heating and cooling cycle subsystem includes a heating unit 400 for providing the heat required on the turbine side and a cooling unit 500 for absorbing heat on the compression side. The gas pipeline of the cooling unit 500 is connected to the compression subsystem 300, and the gas pipeline of the heating unit 400 is connected to the turbine subsystem 200. The input end of the gas storage tank 700 is connected to the cooling unit 500 through a gas pipeline, and the output end of the gas storage tank 700 is connected to the heating unit 400 through a gas pipeline and a first regulating valve 710. The signal output end of the central control subsystem 800 is electrically connected to the control end of the heating unit 400, the control end of the cooling unit 500, and the control end of the first regulating valve 710, respectively.

[0021] The compression subsystem 300 is configured to compress normal air to a high-pressure state. The turbine subsystem 200, the dual-condition synchronous condenser 110, and the drive connection between the turbine subsystem 200 and the dual-condition synchronous condenser 110 are configured to use the high-pressure gas stored in the gas storage tank 700 to drive the dual-condition synchronous condenser 110 to generate electricity during frequency regulation periods. Furthermore, during non-frequency regulation periods, the dual-condition synchronous condenser 110 can also drive the turbine subsystem 200. The hot and cold cycle subsystem is configured to provide the heat required by the turbine side and absorb heat from the compression side. Through the coordinated control of the above subsystems, this invention enables the system to have voltage source characteristics, providing support for the stable operation of the power grid at different stages before, during, and after disturbances, thereby improving the anti-disturbance capability and enabling new energy power plants to actively support the power grid. In this embodiment, the dual-condition synchronous condenser 110 and the compression subsystem 300 are used to connect to the power grid. Specifically, the system also includes a first transformer 250 and a second transformer 350. The dual-condition synchronous condenser 110 is connected to the power grid through the first transformer 250, and the compression subsystem 300 is connected to the power grid through the second transformer 350. In this embodiment, the power output end of the turbine subsystem 200 is rigidly connected to the output shaft of the dual-condition synchronous condenser 110 through a drive shaft.

[0022] like Figure 1and Figure 2 As shown, the turbine subsystem 200 includes a turbine unit and a vacuum pump 260 connected to the turbine unit. The vacuum pump 260 is equipped with a shut-off valve 261 that is electrically connected to the central control subsystem 800. The dual-condition synchronous condenser 110 is connected to the turbine unit through a transmission component, and the gas pipeline of the heating unit 400 is connected to the turbine unit. In this embodiment, the turbine unit includes a primary turbine 210, a secondary turbine 220, and a tertiary turbine 230. The primary turbine 210, secondary turbine 220, and tertiary turbine 230 are all connected to the vacuum pump 260. The primary turbine 210 and the secondary turbine 220, the secondary turbine 220 and the tertiary turbine 230, and the tertiary turbine 230 and the dual-condition synchronous condenser 110 are all connected by drive shafts and bearing housings. Through the drive shafts and bearing housings, the dual-condition synchronous condenser 110 can simultaneously drive the primary turbine 210, the secondary turbine 220, and the tertiary turbine 230 to rotate.

[0023] like Figure 1 and Figure 2 As shown, the heating and cooling cycle subsystem also includes a heat storage unit and a cold storage unit. The input and output ends of the water pipes of the heating unit 400 are connected to the heat storage unit and the cold storage unit, respectively. The input and output ends of the water pipes of the cooling unit 500 are connected to the cold storage unit and the heat storage unit, respectively. The heating unit 400 includes a heater group. The air inlet of the turbine unit is connected to the output end of the air storage tank 700 through the air pipes of the heater group. The input and output ends of the water pipes of the heater group are connected to the heat storage unit and the cold storage unit, respectively.

[0024] In this embodiment, the thermal storage unit includes a thermal storage tank 610, the cold storage unit includes a cold storage tank 620, and the heater group includes a primary heater 410, a secondary heater 420, and a tertiary heater 430. The two ends of the water pipe of the primary heater 410 are connected to the thermal storage tank 610 and the cold storage tank 620, respectively. The two ends of the water pipe of the secondary heater 420 are connected to the thermal storage tank 610 and the cold storage tank 620, respectively. The two ends of the water pipe of the tertiary heater 430 are connected to the thermal storage tank 610 and the cold storage tank 620, respectively. In this embodiment, to facilitate the opening and closing of the thermal storage tank 610 and the flow rate adjustment of the cold storage tank 620, a first water pump 630 is provided at the outlet of the thermal storage tank 610, and a frequency converter and a motor are provided at the first water pump 630; a second water pump 640 is provided at the outlet of the cold storage tank 620, and a frequency converter and a motor are provided at the second water pump 640. To facilitate flow regulation of the water pipes of each heater, a third regulating valve 440 is installed between the water pipe of the first-stage heater 410 and the outlet of the heat storage tank 610, between the water pipe of the second-stage heater 420 and the outlet of the heat storage tank 610, and between the water pipe of the third-stage heater 430 and the outlet of the heat storage tank 610.

[0025] like Figure 1 and Figure 2 As shown, the turbine subsystem 200 also includes a vent silencer 240. In this embodiment, the air inlet of the first-stage turbine 210 is connected to the gas storage tank 700 through the air pipeline of the first-stage heater 410. The air outlet of the first-stage turbine 210 is connected to the air inlet of the second-stage turbine 220 through the air pipeline of the second-stage heater 420. The air outlet of the second-stage turbine 220 is connected to the air inlet of the third-stage turbine 230 through the air pipeline of the third-stage heater 430. The air outlet of the third-stage turbine 230 is connected to the atmosphere through the vent silencer 240. In this embodiment, the first-stage heater 410 is used to heat the inlet air of the turbine subsystem 200; the second-stage heater 420 and the third-stage heater 430 are used for interstage reheat.

[0026] like Figure 1 and Figure 2 As shown, the compression subsystem 300 includes a compressor unit, and the cooling unit 500 includes a cooler group. The outlet of the compressor unit is connected to the input of the air storage tank 700 through the air pipeline of the cooler group. The input and output of the water pipeline of the cooler group are connected to the cold storage tank 620 and the heat storage tank 610, respectively. The cooler group includes a primary cooler 510, a secondary cooler 520, and a tertiary cooler 530. The two ends of the water pipeline of the primary cooler 510 are connected to the heat storage tank 610 and the cold storage tank 620, respectively. The two ends of the water pipeline of the secondary cooler 520 are connected to the heat storage tank 610 and the cold storage tank 620, respectively. The two ends of the water pipeline of the tertiary cooler 530 are connected to the heat storage tank 610 and the cold storage tank 620, respectively. In this embodiment, in order to facilitate the flow regulation of the water pipes of each cooler, a second regulating valve 560 is provided between the water pipe of the first-stage cooler 510 and the outlet of the cold storage tank 620, between the water pipe of the second-stage cooler 520 and the outlet of the cold storage tank 620, and between the water pipe of the third-stage cooler 530 and the outlet of the cold storage tank 620.

[0027] like Figure 1 and Figure 2As shown, the cooling unit 500 also includes a cooling tower assembly connected to the cooler assembly. In this embodiment, the cooling tower assembly includes a four-stage cooler 540 and a cooling tower 550; the compressor assembly includes a primary compressor 310, a secondary compressor 320, and a tertiary compressor 330, and the compression subsystem 300 also includes an air filter 340. Each stage of the compressor is connected to its respective motor via a gearbox. The air inlet of the primary compressor 310 is connected to the atmosphere through the air filter 340, the air outlet of the primary compressor 310 is connected to the air inlet of the secondary compressor 320 through the air pipe of the primary cooler 510, the air outlet of the secondary compressor 320 is connected to the air inlet of the tertiary compressor 330 through the air pipe of the secondary cooler 520, and the air outlet of the tertiary compressor 330 is connected to the air storage tank 700 through the air pipe of the tertiary cooler 530. The water pipe of the fourth-stage cooler 540 is connected to the cooling tower 550, and the air pipe of the fourth-stage cooler 540 is connected to the air pipe of the tertiary cooler 530.

[0028] Preferably, the first-stage compressor 310 and the second-stage compressor 320 are both fixed-frequency compressors, while the third-stage compressor 330 is a variable-frequency compressor. In this embodiment, a third water pump 570 is provided at the outlet of the cooling tower 550 to facilitate the opening and closing of the cooling tower 550 and the adjustment of its flow rate. In this embodiment, to prevent the gas in the gas storage tank 700 from flowing back into the third-stage cooler 530, a check valve 720 and a first regulating valve 710 are provided between the gas pipeline of the third-stage cooler 530 and the inlet of the gas storage tank 700.

[0029] Example 2 This embodiment is a second embodiment of a compressed air energy storage coupled synchronous condenser system. This embodiment is similar to the first embodiment, except that, as Figure 1 and Figure 2 As shown, the dual-condition synchronous condenser system also includes an excitation current regulator 120 electrically connected to the dual-condition synchronous condenser 110; a flow sensor, a temperature sensor, a speed sensor, and a pressure sensor are installed in the hot and cold cycle subsystem; a vibration sensor is installed in the compression subsystem 300; speed sensors are installed at the drive end of the turbine subsystem 200 and at the compression subsystem 300; the signal input terminals of the central control subsystem 800 are electrically connected to the control terminals of the flow sensor, the temperature sensor, the speed sensor, the pressure sensor, and the vibration sensor, respectively; specifically: Flow sensors F1 and F5 are installed at the outlet and inlet ends of the gas storage tank 700, respectively; flow sensors F2, F3, and F4 are installed at the inlet ends of the water pipes of the primary heater 410, the secondary heater 420, and the tertiary heater 430, respectively; flow sensors F8, F7, and F6 are installed at the inlet ends of the water pipes of the primary cooler 510, the secondary cooler 520, and the tertiary cooler 530, respectively; and flow sensor F9 is installed at the outlet end of the cooling tower 550. Temperature sensors T1, T2, and T3 are respectively installed at the outlet ends of the gas lines of the first-stage heater 410, the second-stage heater 420, and the tertiary heater 430; temperature sensors T4, T5, and T6 are respectively installed at the outlet ends of the water lines of the first-stage heater 410, the second-stage heater 420, and the tertiary heater 430; and temperature sensor T7 is inserted into the heat storage tank 610. Temperature sensor T8 is installed at the cold storage tank 620; temperature sensors T11, T10, and T9 are respectively installed at the outlet of the water pipe of the first-stage cooler 510, the outlet of the water pipe of the second-stage cooler 520, and the outlet of the water pipe of the third-stage cooler 530; temperature sensors T12, T13, and T14 are respectively installed at the outlet of the gas pipe of the first-stage cooler 510, the outlet of the gas pipe of the second-stage cooler 520, and the inlet of the gas storage tank 700. A vibration sensor W1 is installed at the drive shaft between the first-stage turbine 210 and the second-stage turbine 220; a vibration sensor W2 is installed at the drive shaft between the second-stage turbine 220 and the third-stage turbine 230; and a vibration sensor W3 is installed at the drive shaft between the third-stage turbine 230 and the dual-condition synchronous condenser 110. Vibration sensors W4, W5, and W6 are respectively installed at the drive shaft between the first-stage compressor 310 and the gearbox, the drive shaft between the second-stage compressor 320 and the gearbox, and the drive shaft between the third-stage compressor 330 and the gearbox. A speed sensor N1 is installed at the drive shaft between the three-stage turbine 230 and the dual-condition synchronous condenser 110; speed sensors N2 and N3 are installed at the first water pump 630 and the second water pump 640, respectively; speed sensors N4, N5, and N6 are installed at the drive shafts between the first-stage compressor 310 and the gearbox, the second-stage compressor 320 and the gearbox, and the third-stage compressor 330 and the gearbox, respectively; and a speed sensor N7 is installed at the third water pump 570. Pressure sensor P1 is installed at the inlet end of the gas pipeline of the first-stage heater 410; pressure sensors P2, P3, and P4 are respectively installed at the outlet ends of the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230; pressure sensors P6, P7, and P8 are respectively installed at the heat storage tank 610, the cold storage tank 620, and the gas storage tank 700; pressure sensor P9 is installed at the inlet end of the first-stage compressor 310; pressure sensors P10, P11, and P12 are respectively installed at the outlet ends of the first-stage compressor 310, the second-stage compressor 320, and the third-stage compressor 330.

[0030] In this embodiment, the sensing subsystem also includes a synchronous condenser status signal sensor B1 and a synchronous condenser status signal sensor B2 respectively disposed at the first transformer 250 and the second transformer 350; it also includes a grid connection point parameter sensor E disposed at the first transformer 250 and a pressure sensor P5 disposed at the vacuum pump 260.

[0031] Example 3 This embodiment is an example of a control method of the present invention, applied to the system described in Embodiment 1 or 2. The control method includes the following control process: When there is no primary frequency regulation requirement of the power grid, the central control subsystem 800 controls the first regulating valve 710 to close, the dual-condition synchronous condenser 110 is in grid-connected state and supplies reactive power to the power grid, the dual-condition synchronous condenser 110 provides power to drive the turbine subsystem 200 to be in an idling state, and at the same time, the phase modulation status signal sensor D inputs the detected signal to the central control subsystem 800; In this embodiment, the dual-condition synchronous condenser 110 switches to electric phase modulation mode, and the dual-condition synchronous condenser 110 drives the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 to be in an idling state, continuously providing rotational inertia to the power grid; and the central control subsystem 800 controls the shut-off valve 261 to open, and the turbine subsystem 200 is in a negative pressure state; When the power grid needs frequency regulation or when the power grid is in a state of large-scale power outage, the central control subsystem 800 controls the first regulating valve 710 to open, and the high-pressure gas stored in the gas storage tank 700 is input into the turbine subsystem 200 to expand and do work. The turbine subsystem 200 provides power to drive the dual-condition synchronous condenser 110 to work in the power generation state. In this embodiment, the dual-condition synchronous condenser 110 is switched to the power generation and phase regulation state by the power provided by the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230.

[0032] Specifically, when there is no primary frequency regulation requirement in the power grid, the central control subsystem 800 controls the first regulating valve 710 to close, the dual-condition synchronous condenser 110 is in grid-connected state and supplies reactive power to the power grid. The central control subsystem 800 controls the dual-condition synchronous condenser 110 to maintain a certain speed through the excitation current regulator 120, and the dual-condition synchronous condenser 110 drives the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 to idle and maintain a certain speed through the drive shaft; the central control subsystem 800 controls the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 to idle and maintain a certain speed. System 800 controls the dual-condition synchronous condenser 110 to maintain a speed of 3000 rpm through excitation current regulator 120, so that the first-stage turbine 210, second-stage turbine 220, and third-stage turbine 230 also maintain a speed of 3000 rpm and are in a rotating standby state; and the central control subsystem 800 controls the shut-off valve 261 to open, and maintains the negative pressure state in the first-stage turbine 210, second-stage turbine 220, and third-stage turbine 230 through vacuum pump 260, so as to solve the problem of overheating of the turbines during idling. It should be further explained that when there is no primary frequency regulation demand from the power grid, the dual-condition synchronous condenser 110 switches from the generator phase regulation mode to the electric phase regulation mode in just 2 seconds. At this time, the first regulating valve 710 is gradually closed, and the dual-condition synchronous condenser 110 is controlled to reduce the generator power to 0MW. The dual-condition synchronous condenser 110 is still in grid-connected state and supplies reactive power to the power grid. The first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 are driven by the dual-condition synchronous condenser 110, so that the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 all maintain an idle speed of 3000rpm, that is, they are in a rotating standby state, continuously providing rotational inertia to the power grid, which can facilitate a rapid response to the primary frequency regulation demand of the power grid in the next operation. The synchronous condenser status signal sensor D monitors the dual-condition synchronous condenser 110 and transmits the detected signal to the central control subsystem.

[0033] Specifically, when frequency regulation is required or when the power grid is in a state of widespread power outage, the central control subsystem 800 controls the first regulating valve 710 to open. The high-pressure gas stored in the gas storage tank 700 is sent to the first-stage turbine 210, the second-stage turbine 220, and the third-stage turbine 230 after passing through the heating unit 400 to expand and do work. Each stage of the turbine converts the pressure potential energy of the compressed air into mechanical energy, so as to drive the dual-condition synchronous condenser 110 to switch to the power generation phase modulation condition to generate electricity. In this embodiment, when frequency regulation is required or the power grid experiences a large-scale power outage, the gas storage tank 700 releases high-pressure air. This high-pressure air passes through the gas pipeline of the primary heater 410 to drive the primary turbine 210. Then, the air passes through the gas pipeline of the secondary heater 420 to drive the secondary turbine 220. Next, the air passes through the gas pipeline of the tertiary heater 430 to drive the tertiary turbine 230. The tertiary turbine 230 converts the pressure potential energy of the compressed air into mechanical energy, causing it to rotate to 3000 rpm. This drives the dual-condition synchronous condenser 110 to switch to the power generation and phase modulation mode for power generation. This switching process takes only 2 seconds. After the power is applied by each turbine, the air is discharged into the atmosphere through the venting silencer 240. It should be noted that the scope of a large-scale power outage can be defined according to the existing State Grid large-scale power outage event classification standards.

[0034] In this embodiment, when the power demand of the power grid is at a low point or during periods of wind curtailment, excess electrical energy is converted into high-pressure air through the primary compressor 310, secondary compressor 320, and tertiary compressor 330. The high-pressure air is cooled through the air pipelines of the primary cooler 510, secondary cooler 520, and tertiary cooler 530, and then transported to the air storage tank 700 for storage. At the same time, the water pipelines of the primary cooler 510, secondary cooler 520, and tertiary cooler 530 absorb the heat released by each compressor during the compression process, and then transport it to the heat storage tank 610 to achieve heat storage.

[0035] In this embodiment, the central control subsystem 800 is existing technology. The AVC response adjustment module and AGC response adjustment module in the central control subsystem 800 can be used to adjust the grid frequency and voltage, respectively, to perform active power frequency regulation or reactive power voltage regulation tasks. During daily operation, the central control subsystem 800 receives AVC commands from the grid and / or adjusts the overall system's operating conditions and modes after receiving AVC commands, while maintaining the operating parameters of each subsystem within a safe, reliable, and reasonable range. Specifically: The central control subsystem 800 can monitor the data from pressure sensors P1, P2, and P3 and regulate each stage of the turbine to keep the outlet pressure of each stage of the turbine within a reasonable range. At the same time, the central control subsystem 800 can monitor the vibration amplitude of each stage of the turbine and the bearing through vibration sensors W1, W2, and W3. In this embodiment, the central control subsystem 800 can monitor the data from pressure sensors P10, P11, and P12 and regulate the compressors at each stage to keep the outlet pressure of each compressor within a reasonable range. At the same time, the central control subsystem 800 can monitor the gear amplitude of each compressor through vibration sensors W4, W5, and W6, and can also monitor the speed of each compressor through speed sensors N4, N5, and N6. In this embodiment, the central control subsystem 800 can monitor the rotational speeds of the first water pump 630 and the second water pump 640 through speed sensors N2 and N3, and adjust the rotational speeds of the first water pump 630 and the second water pump 640 to ensure that the pressure and temperature of the heat storage tank 610 are within a reasonable range. At the same time, the flow sensors corresponding to each stage of the cooler can monitor the flow rate of the circulating water entering each stage of the cooler, and the central control subsystem 800 can regulate the hot and cold circulation subsystem according to the monitoring information to keep the flow rate of the circulating water within a reasonable range. In this embodiment, the central control subsystem 800 can regulate the motors of the compressors at each stage in the compression subsystem 300 and the first regulating valve 710 to ensure that the internal pressure of the gas storage tank 700 does not exceed the maximum set value.

[0036] In this embodiment, when the turbine subsystem 200 outputs low energy, temperature sensors T1, T2, and T3 monitor the gas temperature at the outlet of the gas pipeline at each heater, and temperature sensors T4, T5, and T6 monitor the circulating water temperature at the outlet of the water pipeline at each heater. These temperature sensors are fed back to the central control subsystem 800 via control lines, thereby adjusting the power of the first water pump 630 and the second water pump 640. The frequency converter is adjusted to increase the power of the first water pump 630 and the second water pump 640 to ensure that the low-temperature gas at the turbine outlet can normally absorb the energy stored in the hot circulating water and reach normal temperature. Simultaneously, flow sensors F2, F3, and F4 monitor the circulating water flow rate and feed it back to the central control subsystem 800 via control lines, thereby adjusting each third regulating valve 440 to increase the valve opening and increase the circulating water flow rate, maintaining normal system operation. In this embodiment, when the input energy of the compression subsystem 300 is high, temperature sensors T12, T13, and T14 will monitor the gas temperature at the outlet of each cooler gas pipeline, and temperature sensors T11, T10, and T9 will monitor the circulating water temperature at the outlet of each cooler water pipeline. These temperature sensors will then feed back to the central control subsystem 800 via control lines, thereby adjusting the power of the first water pump 630 and the second water pump 640. The frequency converter will be adjusted to increase the power of the first water pump 630 and the second water pump 640 to ensure that the circulating water can normally absorb and store the excess energy of the high-temperature gas at the outlet of each compressor. Simultaneously, flow sensors F8, F7, and F6 at each cooler will monitor the circulating water flow rate and feed it back to the central control subsystem 800 via control lines, thereby adjusting each second regulating valve 560 to increase the valve opening and increase the circulating water flow rate, maintaining normal system operation. Specifically, the central control subsystem 800 can adjust the grid frequency and perform active frequency regulation through the AGC response adjustment module: when the grid frequency decreases, the air intake of the turbine subsystem 200 needs to be increased, that is, the opening of the first regulating valve 710 at the gas storage 700 is adjusted to increase the air output, and at the same time the frequency converter of the first water pump 630 and the opening of each third regulating valve 440 are adjusted to increase the circulating water flow to maintain stable system operation.

[0037] The central control subsystem 800 can regulate the grid voltage and perform reactive power regulation through the AVC response adjustment module: When the grid voltage deviates from the normal operating condition, based on the parameters transmitted to the central control subsystem 800 by the grid connection point parameter sensor E, the central control subsystem 800 transmits the signal to the excitation current regulator 120 through the control circuit to adjust the excitation current, thereby changing the reactive power output of the dual-condition synchronous condenser 110, thus regulating the grid voltage. At the same time, the synchronous condenser status signal sensor D also reflects the operating parameters of the dual-condition synchronous condenser 110 in real time. The data is fed to the central control subsystem 800 to monitor the operating conditions of the dual-condition synchronous condenser 110. Specifically, the grid connection point parameter sensor E monitors the three-phase voltage, three-phase current, grid frequency, reactive power, active power, power factor, etc., and feeds the results back to the central control subsystem 800 through the control line. After acquiring the real-time monitoring data from the grid connection point parameter sensor E, the central control subsystem 800 adjusts the grid frequency and voltage through the built-in AGC response module or AVC response module to perform active frequency regulation or reactive voltage regulation tasks.

[0038] In this embodiment, in order to meet the primary frequency regulation requirements of the power grid: The pressure sensor P1 monitors the inlet pressure of the first-stage turbine 210, which is also the inlet pressure of the turbine subsystem 200, and feeds it back to the central control subsystem 800. The central control subsystem 800 then controls each turbine to keep the inlet pressure between 2.96 and 5.96 MPa. Specifically, when the pressure sensor P1 detects a pressure greater than or equal to 4.46 MPa, the turbine subsystem 200 operates in throttling mode; when the pressure sensor P1 detects a pressure less than 4.46 MPa, the turbine subsystem 200 operates in supplementary gas mode. The pressure at the outlet of the three-stage compressor 330 is monitored by pressure sensor P12, which is the outlet pressure of the compression subsystem 300. The pressure is then fed back to the central control subsystem 800, which controls each compressor to keep the outlet pressure between 3.04 and 6.04 MPa. The pressure of the gas storage tank 700 is monitored by the pressure sensor P8 and fed back to the central control subsystem 800. The central control subsystem 800 then controls the opening and closing of the first regulating valve 710 and the check valve 720 to keep the pressure of the gas storage tank 700 between 3 and 6 MPa. The pressure and temperature of the thermal storage tank 610 are monitored by pressure sensor P6 and temperature sensor T7 respectively, and the feedback is sent to the central control subsystem 800. Then, the central control subsystem 800 controls the frequency converter and motor at the first water pump 630 to maintain the pressure of the thermal storage tank 610 at 2 MPa, the saturation temperature at 212℃, and the thermal storage temperature at 196℃.

[0039] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A system for compressed air energy storage coupled with a synchronous condenser, characterized in that, It includes a central control subsystem (800), a dual-condition synchronous condenser system, a turbine subsystem (200), and a compression subsystem (300). The dual-condition synchronous condenser system includes a dual-condition synchronous condenser (110) and a synchronous condenser status signal sensor; the turbine subsystem (200) is connected to the dual-condition synchronous condenser (110); the synchronous condenser status signal sensor detects the real-time operating parameters of the dual-condition synchronous condenser (110) and inputs the detected signal to the signal input terminal of the central control subsystem (800); the signal output terminal of the central control subsystem (800) is electrically connected to the control terminal of the dual-condition synchronous condenser (110), the control terminal of the turbine subsystem (200), and the control terminal of the compression subsystem (300), respectively. It also includes a heating and cooling cycle subsystem and a gas storage tank (700) for storing high-pressure gas. The heating and cooling cycle subsystem includes a heating unit (400) for providing the heat required on the turbine side and a cooling unit (500) for absorbing heat on the compression side. The gas pipeline of the cooling unit (500) is connected to the compression subsystem (300), and the gas pipeline of the heating unit (400) is connected to the turbine subsystem (200). The input end of the gas storage tank (700) is connected to the cooling unit (500) through a gas pipeline, and the output end of the gas storage tank (700) is connected to the heating unit (400) through a gas pipeline via a first regulating valve (710). The signal output end of the central control subsystem (800) is electrically connected to the control end of the heating unit (400), the control end of the cooling unit (500), and the control end of the first regulating valve (710), respectively.

2. The compressed air energy storage coupled synchronous condenser system according to claim 1, characterized in that, The turbine subsystem (200) includes a turbine unit and a vacuum pump (260) connected to the turbine unit. The vacuum pump (260) is equipped with a shut-off valve (261) that is electrically connected to the central control subsystem (800). The dual-condition synchronous condenser (110) is connected to the turbine unit through a transmission component, and the gas pipeline of the heating unit (400) is connected to the turbine unit.

3. The compressed air energy storage coupled synchronous condenser system according to claim 2, characterized in that, The heating and cooling cycle subsystem also includes a heat storage unit and a cold storage unit. The input and output ends of the water pipe of the heating unit (400) are connected to the heat storage unit and the cold storage unit, respectively. The input and output ends of the water pipe of the cooling unit (500) are connected to the cold storage unit and the heat storage unit, respectively.

4. The compressed air energy storage coupled synchronous condenser system according to claim 3, characterized in that, The heating unit (400) includes a heater group. The air inlet of the turbine unit is connected to the output of the gas storage tank (700) through the air pipeline of the heater group. The input and output ends of the water pipeline of the heater group are respectively connected to the heat storage unit and the cold storage unit.

5. The compressed air energy storage coupled synchronous condenser system according to claim 3, characterized in that, The compression subsystem (300) includes a compressor unit, the cooling unit (500) includes a cooler unit, the outlet of the compressor unit is connected to the input of the gas storage tank (700) through the gas pipeline of the cooler unit, and the input and output of the water pipeline of the cooler unit are respectively connected to the cold storage unit and the heat storage unit.

6. The compressed air energy storage coupled synchronous condenser system according to claim 5, characterized in that, The cooling unit (500) also includes a cooling tower assembly connected to the cooler assembly.

7. The system for compressed air energy storage coupled to a synchronous condenser according to any one of claims 1 to 6, characterized in that, The dual-condition synchronous condenser system also includes an excitation current regulator (120) electrically connected to the dual-condition synchronous condenser (110).

8. The system for compressed air energy storage coupled to a synchronous condenser according to any one of claims 1 to 6, characterized in that, The hot and cold cycle subsystem is equipped with a flow sensor, a temperature sensor, a speed sensor, and a pressure sensor; the compression subsystem (300) is equipped with a vibration sensor; the transmission end of the turbine subsystem (200) and the compression subsystem (300) are both equipped with speed sensors; the signal input end of the central control subsystem (800) is electrically connected to the control end of the flow sensor, the control end of the temperature sensor, the control end of the speed sensor, the control end of the pressure sensor, and the control end of the vibration sensor, respectively.

9. A control method for a system applied to a compressed air energy storage coupled synchronous condenser as described in any one of claims 1 to 8, characterized in that, The following control processes are included: When there is no primary frequency regulation requirement in the power grid, the central control subsystem (800) controls the first regulating valve (710) to close, the dual-condition synchronous condenser (110) is in grid-connected state and supplies reactive power to the power grid. The dual-condition synchronous condenser (110) provides power to drive the turbine subsystem (200) to be in idling state. At the same time, the synchronous condenser status signal sensor inputs the detected signal to the central control subsystem (800). When the power grid needs frequency regulation or when the power grid is in a state of large-scale power outage, the central control subsystem (800) controls the first regulating valve (710) to open, and the high-pressure gas stored in the gas storage tank (700) is input into the turbine subsystem (200) to expand and do work. The turbine subsystem (200) provides power to drive the dual-condition synchronous condenser (110) to work in the power generation state.

10. The control method according to claim 9, characterized in that, When there is no primary frequency regulation requirement in the power grid, the central control subsystem (800) controls the shut-off valve (261) to open, and the turbine subsystem (200) is in a negative pressure state.

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