JPH1182064A - Gas turbine starting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contract the setting space and reduce the equipment cost by providing a fuel cell for generating a DC power by the fuel of a gas turbine and a reverse converter for imparting the DC power generated by the fuel cell to a synchronous generator until the starting of the gas turbine is completed. SOLUTION: A starting device 5 has a fuel cell 12 for generating a DC power by the fuel of a gas turbine 1, and the DC power generated by the fuel cell 12 is inputted to a reverse converter 10 after removing the ripple by a DC reactor 9. In the reverse converter 10, the DC power from the fuel cell 12 is converted into an AC power having a prescribed variable frequency, and imparted to a synchronous generator 2 through a starting circuit breaker 11. The synchronous generator 2 is synchronously intruded to a power system after its speed becomes the synchronous speed by the starting of the gas turbine 1, and thereafter laid in generating operation. The starting device can be simplified since the fuel cell 12 is used, and contraction of the setting space and reduction in equipment cost can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine starting system using a synchronous generator connected to a gas turbine as a starting motor and starting at a low frequency by a variable frequency power supply.

[0002]

2. Description of the Related Art As a starting device of a gas turbine, a synchronous generator connected to a gas turbine is used as a starting motor, and the synchronous generator is started by supplying a variable frequency power supply from a low frequency to a predetermined frequency. There is something that I did.

FIG. 4 is a configuration diagram in which such a gas turbine starting device is applied to a gas turbine power generation facility. The gas turbine 1 is connected to the synchronous generator 2, and in a normal operation state, the gas turbine 1 drives the synchronous generator 2 by combustion of fuel from the fuel pipe 3, and power is generated by the synchronous generator 2. The power is sent to the power system via the main transformer 4.

On the other hand, when the gas turbine 1 is started, it is necessary to increase the speed of the synchronous generator 2 to a synchronous speed and to synchronously enter the power system. Therefore, a variable frequency power is supplied to the synchronous generator 2 by the starting device 5, the synchronous generator 2 is accelerated to a predetermined speed, and is synchronously incorporated into the power system after the gas turbine 1 is started.

The starting device 5 receives AC power from an in-house power system 6 of a power plant via an input transformer 7, converts the AC power into DC once by a forward converter 8, removes a ripple by a DC reactor 9, and reverses the ripple. Input to the converter 10 to obtain an AC power supply having a predetermined variable frequency. That is, AC power of a variable frequency from 0 frequency to a predetermined frequency is supplied to the synchronous generator 2 through the starting disconnector 11. As a result, the synchronous generator 2 gradually increases in speed from the stopped state to a predetermined rotational speed, and is synchronously incorporated into the power system after reaching the synchronous speed by starting the gas turbine 1. After a while, the power generation operation starts.

As described above, the forward power converter 8 converts the AC power of the in-house power supply system 6 into DC power, and converts the DC power into DC power.
To reduce the ripple of the DC power, and convert the DC power into AC power by the inverter 10. The variable-frequency AC power generated by the starting device 5 is supplied to the synchronous generator 2 through the starting disconnector 11. As a result, the synchronous generator 2 rotates as a synchronous motor from the turning speed (several rotations) to the gas turbine self-sustaining speed (80% to 90% of the rated speed). Thereafter, when the gas turbine 1 is driven by the gas turbine 1 and reaches the synchronous speed, the electric power is synchronously incorporated into the electric power system to perform the power generation operation.

[0007]

However, such a gas turbine starting system has the following problems. (1) Since the input power of the gas turbine starting device 5 is supplied from the in-house power system 6, harmonics generated in the gas turbine starting device 5 flow out to the in-site power system 6. (2) Since the gas turbine starting device 5 is composed of the input transformer 7, the forward converter 8, and the inverse converter 10, the system configuration is complicated. Large, so the generator building needs to be large.

Accordingly, an object of the present invention is to provide a gas turbine start-up system capable of reducing installation space and preventing outflow of harmonics into an in-house power supply system.

[0009]

According to a first aspect of the present invention, there is provided a gas turbine starting system which is started when a gas turbine is started, generates a DC power by fuel of the gas turbine, and a DC power generated by the fuel cell. Is converted into AC power of a predetermined variable frequency and supplied to the synchronous motor until the start of the gas turbine is completed.

In the gas turbine starting system according to the first aspect of the present invention, when starting the gas turbine, a fuel cell that generates DC power using fuel from the gas turbine is started, and the DC power generated by the fuel cell is converted by an inverter. The power is converted into AC power of a predetermined variable frequency and supplied to the synchronous generator until the start of the gas turbine.

According to a second aspect of the present invention, in the gas turbine starting system according to the first aspect of the present invention, after the start of the gas turbine is completed, a communication breaker for connecting the output end of the inverter to the in-house bus is provided. It is provided.

[0012] In the gas turbine starting system according to the second aspect of the present invention, in addition to the operation of the first aspect, after the start of the gas turbine is completed, the output end of the inverter is connected to the local bus by the communication breaker. Then, the electric power generated by the fuel cell is supplied to the load connected to the in-house bus.

A gas turbine starting system according to a third aspect of the present invention is the gas turbine starting system according to the first or second aspect.
The DC power generated by the fuel cell is used as an initial excitation power supply for a synchronous generator.

[0014] In the gas turbine starting system according to the third aspect of the present invention, in addition to the operation of the first or second aspect, the DC power generated by the fuel cell is used as an initial excitation power supply of the synchronous generator.

[0015]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram in which a gas turbine starting system according to a first embodiment of the present invention is applied to a gas turbine power generation facility. This first embodiment is different from the conventional example shown in FIG. 4 in that an input transformer 7 supplied with AC power from an in-house power supply system 6 and a forward converter for converting the AC power to DC power. A fuel cell 12 is provided in place of the fuel cell 12 for generating electric power using the fuel of the gas turbine.

In FIG. 1, a gas turbine 1 is connected to a synchronous generator 2. In a normal operation state, the gas turbine 1 drives the synchronous generator 2 by burning fuel from a fuel pipe 3, and The power generated by the generator 2 is transmitted to the power system via the main transformer 4. On the other hand, when the gas turbine 1 is started, a variable frequency power is supplied to the synchronous generator 2 by the starting device 5, the synchronous generator 2 is accelerated to a predetermined speed, and after the gas turbine 1 is started, it is synchronously incorporated into the power system.

The starting device 5 has a fuel cell 12 for generating DC power by the fuel of the gas turbine 1, and converts the DC power generated by the fuel cell 12 into a DC reactor 9.
To remove the ripple and input to the inverse converter 10. The inverter 10 converts the DC power from the fuel cell 12 into AC power of a predetermined variable frequency and supplies the AC power to the synchronous generator 2 via the starting disconnector 11. That is, AC power of a variable frequency from 0 frequency to a predetermined frequency is supplied to the synchronous generator 2 through the starting disconnector 11. Thereby, the synchronous generator 2
Is gradually increased from the stop state to a predetermined rotation speed, and is synchronously incorporated into the electric power system after reaching a synchronous speed by starting the gas turbine 1. After a while, the power generation operation starts.

As described above, the DC power is generated by the fuel cell 12 using the fuel of the gas turbine 1, the ripple of the DC power is reduced by the DC reactor 9, and the DC power is converted into the AC power by the inverter 10. I do. Starter 5
Is generated and supplied to the synchronous generator 2 through the starting disconnector 11. This allows
The synchronous generator 2 rotates as a synchronous motor from a turning speed (several rotations) to a gas turbine self-sustaining speed (80% to 90% of the rated speed). After a while, the gas turbine 1
When the synchronous speed is reached, the electric power is synchronously incorporated into the electric power system, and the power generation operation is performed.

In the first embodiment, the fuel pipe is branched so that fuel can be supplied to the fuel cell 12 from the middle of the fuel pipe 3 for supplying the gas turbine 1. When the gas turbine 1 is started, the DC power is generated by flowing the fuel of the gas turbine 1 through the fuel cell 12. Then, it is operated as the gas turbine starting device 5 by being combined with the inverter 10.

That is, in the first embodiment, since the fuel cell 12 which can share the fuel (LNG, etc.) of the gas turbine is installed to generate DC power, the input transformer 7 and the forward converter 8 are not required, and The turbine starting system can be simplified. This simplifies the gas turbine start-up system with a low operating rate, reduces the installation space for the start-up device 5, and reduces equipment costs. Further, it is possible to prevent harmonics from flowing out to the power supply system 6 in the office, and to enable startup at the time of blackout.

Next, a second embodiment of the present invention will be described. FIG. 2 is a configuration diagram of a gas turbine starting system according to a second embodiment of the present invention. This second embodiment is different from the first embodiment shown in FIG. 1 in that a communication breaker for connecting the output end of an inverter 10 to an in-house bus after the start of the gas turbine 1 is completed. 13 is provided.

In FIG. 2, a gas turbine 1 is connected to a synchronous generator 2, and in a normal operation state, the gas turbine 1 drives the synchronous generator 2 by burning fuel from a fuel pipe 3. The power generated by the synchronous generator 2 is transmitted to the power system via the main transformer 4. on the other hand,
When the gas turbine 1 is started, a variable frequency power is supplied to the synchronous generator 2 by the starting device 5, the synchronous generator 2 is accelerated to a predetermined speed, and after the gas turbine 1 is started, it is synchronously incorporated into the power system.

The starting device 5 has a fuel cell 12 for generating a DC power by the fuel of the gas turbine 1. The DC power generated by the fuel cell 12 is applied to the DC reactor 9.
And the ripple is removed and input to the inverse converter 10. The inverter 10 converts the DC power from the fuel cell 12 into AC power of a predetermined variable frequency and supplies the AC power to the synchronous generator 2 via the starting disconnector 11. As a result, the synchronous generator 2 rotates as a synchronous motor from a turning speed (several rotations) to a gas turbine self-sustaining speed (80% to 90% of the rated speed), and is thereafter driven by the gas turbine 1 to reach the synchronous speed. It is synchronously incorporated into the power system and power generation is performed.

In this case, when the start of the gas turbine 1 is completed, the start disconnector 11 is opened. Then, thereafter, the communication circuit breaker 13 to the in-house bus is closed, and the power from the starter 5 is supplied to the in-house bus. Thus, the fuel cell 12 that can always supply fuel can be operated and effectively used other than when the gas turbine 1 is started, and the operation rate of the starting device 5 can be improved.

As described above, after the start of the gas turbine 1 is completed, the load on the fuel cell 12 is eliminated, so that the output end of the inverter 10 is connected to the in-house bus to supply power to the load connected to the in-house bus. Supply. Thereby, the fuel cell 1
2 can be used effectively.

Next, a third embodiment of the present invention will be described. FIG. 3 is a configuration diagram of a gas turbine starting system according to a third embodiment of the present invention. This third embodiment is different from the first embodiment shown in FIG.
2 is used as the initial excitation power supply of the synchronous generator 2.

In FIG. 3, the gas turbine 1 is connected to a synchronous generator 2. In a normal operation state, the gas turbine 1 drives the synchronous generator 2 to generate electric power by burning fuel from the fuel pipe 3. ing. The power generated by the synchronous generator 2 is transmitted to the power system via the main transformer 4. Then, the power generated by the synchronous generator 2 is
To rectify the power to be used as an excitation power supply for the synchronous generator 2.

On the other hand, when the gas turbine 1 is started, the starting device 5 supplies a variable frequency power to the synchronous generator 2 to increase the speed of the synchronous generator 2 to a predetermined speed. At that time, the synchronous generator 2 operates as a synchronous motor,
Is not generating electricity. Therefore, the initial excitation is generally supplied from another DC power supply. In the third embodiment, the initial excitation power is supplied from the fuel cell 12.

That is, when the gas turbine 1 is started, the initial excitation contactor 15 and the field circuit breaker 16 are closed, and the initial excitation power is supplied from the fuel cell 12. Then, when the gas turbine 1 is started and the synchronous generator 2 is synchronously incorporated into the electric power system to start power generation, the excitation power is supplied from the rectifier 14, so that the supply of the initial excitation power from the fuel cell 12 is It is no longer necessary, and the initial excitation contactor 15 is opened.

As described above, in the third embodiment, the field power source at the time of startup of the synchronous generator 2 is the DC power source of the fuel cell 12 via the initial excitation contactor 15 and the field breaker 16. Supply to As described above, since the initial excitation power necessary for starting the synchronous generator 2 is obtained from the fuel cell 12, it is possible to reduce the DC power supply capacity that was used for the initial excitation power.

The above description is based on the first embodiment.
Although the DC power generated by the fuel cell 12 is used as the initial excitation power supply of the synchronous generator 2, the DC power generated by the fuel cell 12 is used as the initial excitation power of the synchronous generator 2 in the second embodiment. It goes without saying that it may be used as an excitation power supply.

[0032]

As described above, according to the present invention, since the fuel cell is used in place of the input transformer and the forward converter in the conventional starting device, the starting device can be simplified, the installation space can be reduced, and the equipment can be reduced. Costs can be reduced. In addition, it is possible to prevent harmonics from flowing out to the in-house power supply system, and it is possible to operate a fuel cell capable of constantly supplying fuel even when the gas turbine is not started, and to effectively utilize the fuel cell.

[Brief description of the drawings]

FIG. 1 is a configuration diagram in which a gas turbine starting system according to a first embodiment of the present invention is applied to a gas turbine power generation facility.

FIG. 2 is a configuration diagram in which a gas turbine starting system according to a second embodiment of the present invention is applied to a gas turbine power generation facility.

FIG. 3 is a configuration diagram in which a gas turbine starting system according to a third embodiment of the present invention is applied to a gas turbine power generation facility.

FIG. 4 is a configuration diagram of a conventional gas turbine starting system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Synchronous generator 3 Fuel pipe 4 Main transformer 5 Starting device 6 In-house power supply system 7 Input transformer 8 Forward converter 9 DC reactor 10 Inverter 11 Starting disconnector 12 Fuel cell 13 Communication breaker 14 Rectifier 15 Initial excitation contactor 16 Field breaker

Claims (3)

[Claims] In a gas turbine starting system, a variable frequency power supply is supplied to a synchronous generator connected to a gas turbine to increase the speed of the synchronous generator to a predetermined number of revolutions and start the gas turbine. A fuel cell that is started when the turbine is started to generate DC power by the fuel of the gas turbine, and converts the DC power generated by the fuel cell into AC power of a predetermined variable frequency, and performs the synchronization until the start of the gas turbine is completed. A gas turbine starting system, comprising: an inverter provided to an electric motor. 2. After the start of the gas turbine is completed,
2. The gas turbine starting system according to claim 1, further comprising a communication breaker for connecting an output end of the inverter to an in-house bus. 3. The gas turbine starting system according to claim 1, wherein the DC power generated by the fuel cell is used as an initial excitation power supply of the synchronous generator.