Marine conversion gas turbine generator and phase modifier operation system without clutch

Abstract

The application provides a marine gas turbine generator without clutch and a synchronous condenser operation system, which belongs to the field of marine gas turbine generator units serving as synchronous condensers, and comprises a gas turbine high-pressure turbine section, a gas turbine low-pressure turbine section, a generator, a gas turbine lubricating oil system, a gas turbine hydraulic starting system, a gas turbine control system, a human-machine interface and a generator outlet circuit breaker; the gas turbine high-pressure turbine section, the gas turbine low-pressure turbine section and the generator are sequentially connected; the gas turbine hydraulic starting system and the gas turbine control system are respectively connected with the gas turbine high-pressure turbine section; the human-machine interface is connected with the gas turbine control system; and the gas turbine lubricating oil system is respectively connected with the gas turbine high-pressure turbine section and the gas turbine low-pressure turbine section. The mode switching operation is simple and flexible; the unit can still serve as a rotating standby; there is no increase in hardware cost; the response is fast; the shaft system is light; the power consumption is small; and the power taken from the power grid is small.

Description

Technical Field

[0001] This invention relates to the field of using aero-derivative gas turbine generator sets as synchronous condensers, and more specifically, to a clutchless aero-derivative gas turbine generator and its operating system as a synchronous condenser. Background Technology

[0002] Aero-derived gas turbine generator sets mainly consist of an aero-derived gas turbine and a generator. Under normal operating conditions, they operate in power generation mode, providing a certain amount of active power and a small amount of reactive power to the power grid. However, under certain special operating conditions, such as when the power grid's reactive power reserve is insufficient, the aero-derived gas turbine generator must respond to the grid's requirements and undertake the task of reactive power regulation. Therefore, the aero-derived gas turbine generator should have the capability to operate as a synchronous condenser.

[0003] Existing aero-derivative gas turbine generator sets must be equipped with a clutch if they are to be used as synchronous condensers. The reason is that in the "reverse" operation mode, i.e., as a synchronous condenser, the generator drives the low-pressure turbine of the gas turbine coaxially, while the low-pressure turbine rotor drives the high-pressure turbine rotor at a low speed via air coupling. The lubrication level of the gas turbine shaft system depends on the speed of the high-pressure turbine rotor. At this time, the high-pressure turbine rotor speed is low, resulting in insufficient lubrication and failing to meet the lubrication requirements of the gas turbine shaft system, affecting the safety of the gas turbine equipment. Therefore, given the separate shaft design of the high and low-pressure turbine rotors and the unique design of its lubrication system, a clutch must be used to separate the generator shaft from the gas turbine shaft system, allowing the generator to operate independently as a synchronous motor under no-load conditions to achieve phase-shifting functionality. However, this also means that the gas turbine generator set cannot meet the requirements of being a rotating standby unit for the power grid. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a clutchless aero-derivative gas turbine generator and synchronous condenser operating system.

[0005] According to the present invention, a clutchless aero-derivative gas turbine generator as a synchronous condenser operating system includes: a high-pressure turbine section of a gas turbine, a low-pressure turbine section of a gas turbine, a generator, a gas turbine lubricating oil system, a gas turbine hydraulic starting system, a gas turbine control system, a human-machine interface, and a generator output circuit breaker. The high-pressure turbine section, the low-pressure turbine section, and the generator are connected sequentially. The gas turbine hydraulic starting system and the gas turbine control system are respectively connected to the high-pressure turbine section of the gas turbine. The human-machine interface is connected to the gas turbine control system. The gas turbine lubricating oil system is respectively connected to the high-pressure turbine section and the low-pressure turbine section. The generator is connected to the generator output circuit breaker.

[0006] Preferably, the gas turbine control system triggers the corresponding control logic through the operating mode selected by the human-machine interface;

[0007] When the generator operation mode is selected on the human-machine interface, the gas turbine control system triggers the execution of normal logic.

[0008] When the human-machine interface selects the synchronous condenser mode, the gas turbine control system triggers the execution of the main logic and secondary logic.

[0009] Preferably, the main logic operation steps are as follows:

[0010] S1. The gas turbine control system will automatically control the high-pressure turbine section and the low-pressure turbine section of the gas turbine to maintain the minimum load operation, and keep the rotor of the high-pressure turbine section of the gas turbine running at a minimum speed of 1100 RPM.

[0011] S2. Cut off the fuel supply while keeping the generator outlet circuit breaker in the closed position, and maintain the low-pressure turbine section of the gas turbine and the coaxial generator rotor at the power frequency speed.

[0012] S3. The generator excitation system will adjust the excitation according to the grid demand, absorb or generate reactive power, and achieve the purpose of phase adjustment.

[0013] The preferred sub-logic operation steps are as follows:

[0014] S1. The gas turbine control system monitors the rotational speed of the high-pressure turbine rotor in real time.

[0015] S2. When the rotor speed of the high-pressure turbine section of the gas turbine is detected to be lower than 1100 RPM, the hydraulic start system of the gas turbine is activated to accelerate the rotor speed of the high-pressure turbine section of the gas turbine to above 1500 RPM.

[0016] When the human-machine interface selects the synchronous condenser mode, the generator runs in reverse, driving the low-pressure turbine section of the gas turbine to rotate synchronously at the power frequency.

[0017] Preferably, under the premise that the high-pressure turbine section and the low-pressure turbine section of the gas turbine are not ignited, the gas turbine hydraulic starting system accelerates the rotor of the high-pressure turbine section of the gas turbine to more than 2000 RPM.

[0018] Preferably, the generator has the capability to operate in the leading phase mode, and the temperature rise at the stator end of the generator does not exceed the limit in the leading phase operation mode.

[0019] Preferably, the generator can directly switch between rotating hot mode and generator operating mode.

[0020] Preferably, the rotational speed of the high-pressure turbine section rotor of the gas turbine is inversely proportional to the shaft system safety of the high-pressure turbine section and the low-pressure turbine section of the gas turbine, respectively, and the rotational speed of the high-pressure turbine section rotor of the gas turbine is directly proportional to the oil quantity and oil pressure of the gas turbine lubrication oil system.

[0021] The present invention also provides an aero-derivative gas turbine generator, including an aero-derivative gas turbine generator operating system without a clutch.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The mode switching operation of this invention is simple and flexible; the unit can still be used as a rotating standby unit; there is no increase in hardware costs; the response is fast; the shaft system is lightweight, the power consumption is low, and the power draw from the grid is minimal. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 A diagram of the synchronous condenser operation system for the aero-derivative gas turbine generator set of the present invention;

[0026] Figure 2 This is the main logic block diagram of the present invention;

[0027] Figure 3 This is a block diagram of the sub-logic of the present invention.

[0028] The diagram shows: 1-Gas turbine high-pressure turbine section, 2-Gas turbine low-pressure turbine, 3-Generator, 4-Gas turbine lubrication oil system, 5-Gas turbine hydraulic starting system, 6-Gas turbine control system, 7-Human machine interface, 8-Generator outlet circuit breaker (52G). Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0030] Example 1

[0031] According to the present invention, a clutchless aero-derivative gas turbine generator as a synchronous condenser operating system is provided, such as... Figure 1-3As shown, the system includes a high-pressure turbine section 1, a low-pressure turbine section 2, a generator 3, a gas turbine lubrication system 4, a gas turbine hydraulic starting system 5, a gas turbine control system 6, a human-machine interface 7, and a generator output circuit breaker (52G) 8. The high-pressure turbine section 1, low-pressure turbine section 2, and generator 3 are connected sequentially. The gas turbine hydraulic starting system 5 and the gas turbine control system 6 are respectively connected to the high-pressure turbine section 1. The human-machine interface 7 is connected to the gas turbine control system 6. The gas turbine lubrication system 4 is connected to both the high-pressure turbine section 1 and the low-pressure turbine section 2. The generator 3 is connected to the generator output circuit breaker 8. The hardware configuration remains unchanged, resulting in no additional cost. When the human-machine interface 7 is set to synchronous condenser mode, the generator 3 operates in reverse, driving the low-pressure turbine section 2 to rotate synchronously at the power frequency. This eliminates the need for high-speed rotation of the entire gas turbine shaft system, resulting in lower power consumption.

[0032] With neither the high-pressure turbine section 1 nor the low-pressure turbine section 2 of the gas turbine ignited, the gas turbine hydraulic starting system 5 accelerates the rotor of the high-pressure turbine section 1 to over 2000 RPM. Generator 3 has the capability for leading-phase operation, and factory testing has verified that the stator end temperature rise of generator 3 does not exceed limits in leading-phase operation mode. Without a clutch, the high-pressure turbine section 1 and the low-pressure turbine section 2 of the gas turbine are separated from generator 3, allowing generator 3 to still serve as a rotating (thermal) standby, ready to respond to grid demands and switch back to generator operation.

[0033] The gas turbine control system 6 triggers corresponding control logic based on the operating mode selected through the human-machine interface 7. When the generator operating mode is selected on the human-machine interface 7, the gas turbine control system 6 triggers the execution of conventional logic; when the synchronous condenser mode is selected on the human-machine interface 7, the gas turbine control system 6 triggers the execution of both main and secondary logic. User operation is simple; the system only needs to select and switch operating modes on the human-machine interface, and the control system will automatically adjust to the required operating mode according to the user's selection, making operation flexible and convenient.

[0034] The main logic operation steps are as follows:

[0035] S1. The gas turbine control system 6 will automatically control the high-pressure turbine section 1 and the low-pressure turbine section 2 of the gas turbine to maintain the minimum load operation, and keep the rotor of the high-pressure turbine section 1 of the gas turbine running at a minimum speed of 1100 RPM.

[0036] S2. Cut off the fuel supply, while keeping the generator outlet circuit breaker 8 in the closed position, and the rotor of the gas turbine low-pressure turbine section 2 and the coaxial generator 3 maintain the power frequency speed.

[0037] S3, the excitation system of generator 3 will adjust the excitation according to the grid demand, absorb or generate reactive power, and achieve the purpose of phase adjustment.

[0038] The next logical operation steps are as follows:

[0039] S1, Gas turbine control system 6 monitors the rotational speed of the high-pressure turbine section rotor in real time;

[0040] S2. When the rotor speed of the high-pressure turbine section 1 of the gas turbine is detected to be lower than 1100 RPM, the gas turbine hydraulic starting system 5 is activated to accelerate the rotor of the high-pressure turbine section 1 of the gas turbine to above 1500 RPM.

[0041] The rotational speed of the rotor in the high-pressure turbine section 1 of the gas turbine directly affects the quantity and pressure of the lubricating oil in the shaft system. Therefore, it is necessary to maintain the rotor speed above the required level to ensure the safety of the turbine shaft system.

[0042] The aero-derivative gas turbine has a short start-up and shutdown time and a fast response. The entire process of switching from generator mode to synchronous condenser operation mode takes no more than 3 minutes, as shown in the table below. Therefore, it has a natural advantage whether it is used as a synchronous generator or as a synchronous condenser.

[0043]

[0044]

[0045] More specifically, the conventional logic follows the normal startup procedure of a gas turbine in standard power generation mode. The gas turbine first establishes its speed from zero. When the high-speed shaft speed reaches approximately 10,000 RPM, the low-speed shaft and generator shaft of the gas turbine are driven to establish their speeds through a startup coupling method until the power frequency speed is reached. During the establishment and ramp-up of the high-speed shaft speed, the lubrication system will adjust the lubrication oil pressure and quantity in the positive direction according to its speed to ensure sufficient lubrication of the shaft system.

[0046] The generator's excitation system is an automatic system for the gas turbine generator. When the system's reactive power is insufficient, the excitation system increases the excitation current, causing the gas turbine generator to operate in a further over-excited state, supplying inductive reactive power to the power grid to compensate for the reactive power deficit. Conversely, when the system has excess reactive power, the excitation system reduces the excitation current, causing the gas turbine generator to operate in an under-excited state, absorbing the excess inductive reactive power from the power grid, thus achieving a balance between reactive power supply and demand in the power grid. This reactive power balance significantly improves the operational safety and stability of the power grid and its distribution equipment, while also greatly increasing the grid's efficiency and reducing line losses.

[0047] Example 2

[0048] The present invention also provides an aero-derivative gas turbine generator, including the clutchless aero-derivative gas turbine generator as a synchronous condenser operating system in Embodiment 1.

[0049] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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, they should not be construed as limitations on this application.

[0050] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A clutchless aero-derivative gas turbine generator operating system for synchronous condenser operation, characterized in that, include: The gas turbine high-pressure turbine section (1), gas turbine low-pressure turbine section (2), generator (3), gas turbine lubrication oil system (4), gas turbine hydraulic starting system (5), gas turbine control system (6), human-machine interface (7), and generator outlet circuit breaker (8) are connected in sequence. The gas turbine high-pressure turbine section (1), the gas turbine low-pressure turbine section (2), and the generator (3) are connected in sequence. The gas turbine hydraulic starting system (5) and the gas turbine control system (6) are respectively connected to the gas turbine high-pressure turbine section (1). The human-machine interface (7) is connected to the gas turbine control system (6). The gas turbine lubrication oil system (4) is respectively connected to the gas turbine high-pressure turbine section (1) and the gas turbine low-pressure turbine section (2). The generator (3) is connected to the generator outlet circuit breaker (8). The gas turbine control system (6) triggers the corresponding control logic through the operating mode selected by the human-machine interface (7); When the human-machine interface (7) selects the generator operation mode, the gas turbine control system (6) triggers the execution of normal logic; When the human-machine interface (7) selects the synchronous condenser mode, the gas turbine control system (6) triggers the execution of the main logic and the secondary logic; The main logic operation steps are as follows: S1. The gas turbine control system (6) will automatically control the gas turbine high-pressure turbine section (1) and the gas turbine low-pressure turbine section (2) to maintain the minimum load operation, and keep the rotor of the gas turbine high-pressure turbine section (1) running at a minimum speed of 1100 RPM. S2. Cut off the fuel supply while keeping the generator outlet circuit breaker (8) in the closed position. The low-pressure turbine section (2) of the gas turbine and the coaxial generator (3) rotor maintain the power frequency speed. S3. The excitation system of the generator (3) will adjust the excitation according to the grid demand, absorb or generate reactive power, and achieve the purpose of phase adjustment.

2. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, The steps of the next logical operation are as follows: S1. The gas turbine control system (6) monitors the rotational speed of the high-pressure turbine section rotor in real time; S2. When the rotor speed of the high-pressure turbine section (1) of the gas turbine is detected to be lower than 1100 RPM, the hydraulic start system (5) of the gas turbine is turned on to accelerate the rotor of the high-pressure turbine section (1) of the gas turbine to more than 1500 RPM.

3. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, When the human-machine interface (7) selects the synchronous condenser mode, the generator (3) runs in reverse and drives the low-pressure turbine section (2) of the gas turbine to rotate synchronously at the power frequency.

4. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, Without ignition of the high-pressure turbine section (1) and the low-pressure turbine section (2) of the gas turbine, the gas turbine hydraulic starting system (5) accelerates the rotor of the high-pressure turbine section (1) of the gas turbine to more than 2000 RPM.

5. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, The generator (3) has the capability of advancing phase operation, and the temperature rise at the stator end of the generator (3) does not exceed the limit in the advancing phase operation mode.

6. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, The generator (3) can switch directly between rotating thermal mode and generator operation mode.

7. The clutchless aero-derivative gas turbine generator as synchronous condenser operating system according to claim 1, characterized in that, The rotational speed of the rotor of the high-pressure turbine section (1) of the gas turbine is inversely proportional to the safety of the shaft system of the high-pressure turbine section (1) and the low-pressure turbine section (2) of the gas turbine, and the rotational speed of the rotor of the high-pressure turbine section (1) of the gas turbine is directly proportional to the oil quantity and oil pressure of the lubricating oil system (4) of the gas turbine.

8. A modified gas turbine generator, characterized in that, Includes the clutchless aero-derivative gas turbine generator as synchronous condenser operating system as described in any one of claims 1-7.

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