DE112013006890T5 - Power generation system - Google Patents

Abstract

There is provided a technique that can reduce a time required to establish a system connection in a power generation system while avoiding the generation of overvoltage with respect to that connection. A power generation system comprises a power source 2, a power generator 3 powered by the power source 2, a first breaker 30 disposed between the power generator 3 and an AC system 100, a first power converter 5 connected to the power generator 3 side of the first one Breaker 30 is connected, and a controller 10 which controls an opening and closing of the first breaker 30 and a switching of the first power converter 5. The controller 10 controls the first breaker 30 to be closed after the start of switching of the first power converter 5.

Description

Technical area

The present invention relates to a power generation system, in particular, a starting operation of the power generation system.

State of the art

A method for starting a gas turbine is described, for example, in Patent Literatures 1 and 2. In this case, a compressor and a turbine are set in rotation by means of a starter motor, and the ignition of fuel begins when the number of revolutions has increased to a predetermined number, so as to achieve a sufficient compressor drive force. Then, the number of revolutions is increased up to a target revolution number by adjusting the fuel amount or a compressor-air intake amount. After a phase difference between a voltage of a connected system and a terminal voltage of the power generator has fallen within a predetermined range, a breaker arranged between the power generator and the power system is operated, and the system connection with the gas turbine power generation system is terminated.

By operating the breaker in a period in which the phase difference between the terminal voltage of the power generator and the voltage of the system is low, it is possible to overvoltage the power generator with respect to the system connection and fluctuation of the system voltage related to the connection avoid.

CITATION

patent literature

• Patent Literature 1: Japanese Unexamined Patent Application, Laid-Open No. Hei 6-264766
• Patent Literature 2: tested Japanese Patent Publication No. Sho 59-9737

Summary of the invention

Technical problem

In a general power generation system, it takes time to control a power source such that the phase difference between the terminal voltage of the power generator and the system voltage is reduced until the power generator and the system are connected together.

For example, a twin-shaft gas turbine may have a more compact structure compared to a single-shaft gas turbine, however, adjusting the phase difference between the system voltage and the terminal voltage of the power generator is difficult because a driving force of the second turbine is controlled indirectly via the exhaust gas of the first turbine. Further, since the fuel supply and the adjustment of the air intake amount are performed by mechanical operations, a longer time is required for controlling the exhaust gas amount by means of these settings and setting a condition suitable for the system connection.

The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a technique for reducing a time required for system connection of a power generation system while avoiding overvoltage in that connection.

the solution of the problem

The present invention includes a plurality of solutions to the above problem. As an exemplary solution, a power generation system according to the present invention comprises an energy source; a power generator driven by the power source; a first breaker disposed between the power generator and an AC system; a first power converter connected to the power generator on the side of the first breaker; a controller for controlling the opening and closing of the first breaker and switching the first power converter. The controller performs a control of closing the first breaker after starting the switching of the first power converter.

Advantageous Effects of the Invention

In a power generation system according to the present invention, it is possible to directly control a rotor torque for reducing the phase difference between a voltage of a system and an output voltage of the power generator, and thereby the time required for the starting operation of the power generation system can be reduced. It is also possible to connect a dual shaft gas turbine system to a system while avoiding the generation of overvoltage in the connection.

Brief description of the figures

1 Fig. 10 is an explanatory diagram of a first embodiment of the present invention.

2 Fig. 10 is an explanatory diagram of a gas turbine constituting the first embodiment of the present invention.

3 is an explanatory diagram of an inverter 5 which forms the first embodiment of the present invention.

4 is a second form of inverter 5 which forms the first embodiment of the present invention.

5 is an explanatory diagram of a controller 100 of a gas turbine power generation system constituting the first embodiment of the present invention.

6 FIG. 10 is an explanatory diagram of a flowchart of operation of a state controller. FIG 101 in the controller 100 ,

7 is an explanatory diagram of an inverter controller 102 in the controller 100 ,

8th Fig. 10 is an explanatory diagram of a second embodiment of the present invention.

9 is an explanatory diagram of a controller 100Ab of a gas turbine power generation system constituting the second embodiment of the present invention.

10 FIG. 10 is an explanatory diagram of a flowchart of operation of a state controller. FIG 101ab in the controller 100Ab ,

11 is a diagram of an inverter control 102B in the controller 100Ab ,

12 Fig. 10 is an explanatory diagram of a third embodiment of the present invention.

13 is an explanatory diagram of a controller 100AB2 of a gas turbine power generation system constituting the third embodiment of the present invention.

14 is an explanatory diagram of the operation of a state controller 101AB2 in the controller 100AB2 ,

15 is an explanatory diagram of an inverter controller 102A2 in the controller 100AB2 ,

16 is an explanatory diagram of an inverter controller 102B2 in the controller 100AB2 ,

17 Fig. 12 is an explanatory diagram of an alternative to the first embodiment of the invention.

18 Fig. 12 is an explanatory diagram of an alternative to the first embodiment of the invention.

19 Fig. 12 is an explanatory diagram of an alternative to the second embodiment of the present invention.

20 Fig. 10 is an explanatory diagram of a fourth embodiment of the present invention.

21 Fig. 10 is an explanatory diagram of the fourth embodiment of the present invention.

22 Fig. 12 is an explanatory diagram of an alternative to the third embodiment of the present invention.

23 Fig. 10 is an explanatory diagram of a fifth embodiment of the present invention.

Description of the embodiments

A first embodiment of the present invention will be explained below with reference to the drawings.

First embodiment

A gas turbine power generation system using natural gas has received increased attention as the price of crude oil has increased in recent years, and techniques for extracting shale gas have been provided. Further, a gas turbine power generation system generally has a shorter startup compared to power generation systems using steam turbines, so that one hopes for a higher contribution to system stabilization in the context of the introduction of renewable energy due to the short startup.

As a gas turbine power generation system, there are single shaft gas turbine power generation systems having a compressor, a turbine, and a power generator mechanically connected to a single shaft and dual shaft gas turbine power generation systems including a first turbine, a second turbine coupled to a shaft which is not mechanically connected to a shaft of the first turbine, and which receives a driving torque via exhaust gas from the first gas turbine, and with a power generator having a rotor mechanically connected to the shaft of the second turbine.

The dual-shaft gas turbine power generation system has the advantage that a possible generated power is greater than that of a single-shaft gas turbine power generation arrangement having the same wavelength.

In a twin-shaft gas turbine power generation system of this embodiment, it is possible to achieve the phase of an output voltage of a power generator at a higher speed than in the case of a phase adjustment by means of exhaust gas.

A structural diagram of the gas turbine power generation system of the first embodiment of the present invention is shown in FIG 1 shown. The gas turbine power generation system 1 gets rough from a gas turbine 2 , an energy generator 3 , a starter motor 4 , an inverter 5 and a controller 10 educated. The energy generator 3 is over a breaker 30 with an AC system 100 connected. The starter motor 4 is via a transformer 51 and a breaker 31 with the AC system 100 connected.

This embodiment is an example of a control method of a power generation system during a startup sequence in which the switching operations of the inverter are started, then an energy output of the inverter to the power generator is controlled so as to reduce a polarity of a phase difference between a voltage of the AC system and a terminal voltage of the power generator and then the breaker 30 is operated, or an example of such a system.

The inverter 5 is with the energy generator 3 connected in parallel and a connection point of the same is on the energy generator 3 facing side of the breaker 30 arranged. A power for the inverter 5 is powered by a DC power supply 7 provided.

The gas turbine power generation system is equipped with various types of sensors for operating the gas turbine, such as current sensors 60uv and 60vw , each for detecting a system AC voltage, voltage sensors 61uv and 61vw each for detecting a power generator output voltage, current sensors 62u and 62w each for detecting an output current of the inverter 5 , a speed sensor 63 for detecting the number of revolutions of a compressor of the gas turbine 2 and a speed sensor 64 for detecting the number of revolutions of a shaft which the rotor of the power generator 3 and the gas turbine 2 mechanically interconnected.

The outputs of the aforementioned sensors are with the controller 10 connected. The control 10 receives from a system controller, not shown, a start command StartCMD input thereto and gives breaker open / close commands 30CMD and 31CMD , a command BrennstoffCMD for feeding fuel of the gas turbine 2 , an opening command IGVCMD for an inlet guide of the compressor 2 , and a gate signal GateSig of a semiconductor switching device in the inverter 5 out.

Although the details are described later, the controller operates 10 the breaker 31 for starting the power supply of the starter motor 4 when the start command StartCMD is input from the Control Panel. The starter motor 4 is an induction motor and converts the received energy into a rotational torque, and displaces the compressor and a turbine of the gas turbine 2 in rotation. When the number of revolutions of the compressor has increased to a predetermined number, fuel is ignited to start a self-sustaining rotation of the gas turbine 2 to effect, and the breaker 31 is opened so as to supply power to the starter motor 4 to stop. The turbine connected to the rotor of the power generator receives due to fuel combustion in the gas turbine 2 a driving force, and the rotor of the power generator 3 turns. The inverter 5 controls a power such that the phase of the terminal voltage of the power generator is close to the phase of the system voltage. When the phase difference has dropped below a predetermined value, the breaker becomes 30 operated, and the power generation for the AC system 100 starts. At the same time, the energy generator 3 controlled by an excitation controller, which is not shown, so that the terminal voltage of the power generator coincides with a desired value.

2 shows a main structure of the gas turbine 2 , The gas turbine 2 is formed by a compressor 20 , which mainly compresses air, a combustion chamber 21 , which fuel, which is supplied from a fuel tank, not shown, with that of the compressor 20 supplied compressed air mixes and burns, a high pressure side turbine 22 by absorbing an expansion force of the exhaust gas from the combustion chamber 21 is set in rotation, a low-pressure turbine 23 , which is a rotational torque by absorbing exhaust gas from the turbine 22 gets a rotating shaft, which is the compressor 20 and the high-pressure side turbine 22 mechanically interconnects to a rotational torque of the compressor 20 to transmit, as well as a wave 25 , which for transmitting a rotational torque of the rotor of the power generator 3 with the low-pressure side turbine 23 connected is.

The compressor 20 the gas turbine 2 is with an inlet guide baffle (hereinafter referred to as IGV) 26 for adjusting the flow rate of the air taken in by the compressor and a valve 27 for adjusting in the combustion chamber 21 supplied fuel quantity equipped. The fuel gets over lines 270 and 271 fed into the combustion chamber. The one from the compressor 20 compressed air is through a pipe 201 fed into the combustion chamber. The exhaust gas of the combustion chamber 21 is through a pipe 210 the high pressure side turbine 22 fed.

The controller receives as input the various in 1 shown sensors and the start command StartCMD, represents the opening of the IGV 26 and the opening of the fuel valve 27 and maintains stable combustion in the combustion chamber.

The structure of the inverter 5 is referred to 3 described.

The inverter 5 This embodiment is a 2-stage inverter formed by three arms in which two IGBT devices are connected in series.

The IGBT devices 5 m to 5r are formed by an IGBT and a diode which is connected in antiparallel circuit with the IGBT. The gate signal GateSig output from the controller becomes a gate as a control electrode of the IGBT device 5 m to 5r so that the IGBT is controlled to turn on and off. The inverter 5 outputs an alternating current to the terminals U, V and W containing high harmonic frequencies in which the on / off ratio of the IGBT device is adjusted.

A reactor 5fil is provided for suppressing the harmonic currents caused by the above-mentioned high harmonics.

The DC power supply 7 is connected to the terminals P and N. The DC power supply 7 provides DC power for the inverter 5 ready or provides a constant DC voltage by charging with DC power. Although the inverter 5 with the energy generator 3 and the AC system via the reactor 5fil in 3 is connected, can reduce the harmonic reducing effect of a transformer 5tr by its loss induction as in 4 shown used as a harmonic filter. The use of the transformer 5tr enables the selection of an IGBT with the appropriate current and voltage specification regardless of the system AC voltage, thus increasing the flexibility of the design.

The transformer 5tr and the reactor 5fil may work if provided independently, or both may be provided.

The inverter 5 is described in this embodiment as a 2-stage inverter. However, the inverter structure is not limited to the 2-stage structure. The same advantageous effect can be achieved, for example, by multi-stage inverters as they are in 4 are shown as a 3-stage inverter can be achieved. If the inverter 5 as in 4 shown is a 3-stage inverter, the number of signals in the controller increases 10 output gate signal from 6 on 12 ,

The structure of the controller 10 of the gas turbine power generation system 1 is referred to 5 described.

The control 10 is formed by a state controller 101 which state transitions of the gas turbine power generation system 1 controls, an inverter control 102 indicating the gate signals for the inverter 5 calculated, and a turbine control 103 which the fuel valve 27 and the IGV 26 the gas turbine 2 controls.

The state control 101 uses the start command StartCMD, the revolution number N_HPT of the high-pressure side turbine, and the revolution number N_LPT of the low-pressure-side turbine as its input signals and gives the start command 5CMD for the inverter 5 , a combustion start command 21CMD for the gas turbine 2 , and an open / close command 30CMD and 31CMD for the breakers 30 and 31 out.

The inverter control 102 uses system AC voltages vuv_g and vvw_g, output voltages vuv_s and vvw_s of the power generator 3 , Output currents iu and iw of the inverter 5 , and the start command 5CMD for the inverter 5 as an input signal, and calculates GateSig, the gate signal, for the IGBT devices 5 m to 5r and spend it.

The turbine control 103 uses the numbers of revolutions N_HPT and N_LPT of High-pressure side turbine and the low-pressure side turbine and the combustion start command 21CMD as its inputs, and outputs a fuel valve control signal fuel CMD and an IGV open command IGVCMD. The operation of the turbine control 103 takes place according to a known method, wherein the operation of the state control 101 and the inverter control 102 contains characteristic structures of this embodiment. The latter are referring to the 6 and 7 described.

In 6 Fig. 12 is a flowchart of an operation by the state controller 101 shown. As on the right in 6 4, a rectangle represented by a single line represents a state, while a rectangle represented by double lines represents the decision to a condition. A state transition condition is shown to the left of "/", and an output signal associated with the state transition is shown to the right of "/".

Until the start command StartCMD is input, the state control remains in a stopped state S1. When StartCMD is entered, 31CMD switched from an opening command to a closing command to the breaker 31 to press. The condition is then switched to a breaker 31 Operation state S2 switched.

By the operation of the breaker 31 receives the starter motor 4 a driving force. The wave 24 , the compressor 20 and the high pressure side turbine 22 Therefore, they begin to rotate and the numbers of revolutions gradually increase.

When the number of revolutions N_HPT of the high-pressure side turbine 22 is a predetermined number N_Fire or less, no state transition is performed. If N_HPT exceeds N_Fire, the start command will be issued 21CMD the gas turbine 2 activated, and the breaker 31 is switched from the closing command to the opening command. After changing the commands 21CMD and 31CMD , the state changes to a state S3.

An operation of the state change for the inverter control including the characteristic constitution of this embodiment will be described below.

By starting the combustion in the combustion chamber 21 gets the low pressure side turbine 23 a driving force, and the number of revolutions N_LPT increases. If N_LPT is greater than a first predetermined number N_min (eg, 90% of a target number of revolutions for the low pressure side turbine) and less than a second predetermined value N_max (eg, 110% of the target number of revolutions of the low pressure side turbine) which is greater than the first predetermined value N_min, activates the state control 101 the start command 5CMD for the inverter 5 and gives this to the inverter controller 102 out.

By setting the condition for starting the inverter 5 such that a deviation between the number of revolutions 5 the low-pressure-side turbine and the target revolution number is about 10%, it is possible that in the DC power supply 7 to reduce accumulated energy.

The inverter control 102 Sets the gate signal GateSig such that an AC power, which is the deviation between the phase of the output voltage of the power generator 3 and the phase of the AC system voltage to the inverter 5 and, as described later, to the inverter 5 is issued.

The state controller changes the state into an inverter 5 Start state S4. If an amount │Δθ│ for the phase difference, by the inverter control 102 is outputted for a predetermined time Tchk is less than a predetermined value .DELTA.θmax, changes the state control 101 the command for the breaker 31 from the opening command to the closing command, and the starting operation of the gas turbine power generation system is finished.

If the number of revolutions of the rotor of the energy generator 3 not with the frequency of the AC system 100 Δθ fluctuates at a frequency which is the difference between the frequency of the energy generator 3 output AC voltage and the frequency of the AC system 100 equivalent. By setting Δθmax and the decision time Tchk to, for example, 5 degrees and 1 second, an erroneous decision of the power generator synchronization caused by the frequency difference can be avoided and an amplitude of a transmission current of the power generator generated when the power generator the AC system 100 can be reduced because a permissible phase difference is reduced to 5 degrees or less. In general, a power generator winding impedance of 100% or more of the self-capacitance is provided. In the case of a phase difference of 5 degrees, a current related to the operation of the power generator and caused by the phase difference can be reduced to 10% or less of the target current, and a disturbance of the AC system 100 can be reduced.

In a conventional gas turbine power generation system, the phases of the output voltage of the power generator 3 and the voltage phase of the AC system is adjusted only by mechanical input. Particularly, in the case of a double-shaft gas turbine, the driving force of the low-pressure side turbine has to be adjusted indirectly by the exhaust gas of the high-pressure side turbine, and the phase adjustment of the power generator therefore takes much time.

In the gas turbine power generation system of this embodiment, it is possible to directly control the driving force of the power generator to a high speed by introducing power. Compared to the gas turbine power generation system in which the phase adjustment is made only by mechanical input, the phase adjustment can be done at a higher speed.

Next, an operation of the inverter controller 102 , which achieves the aforementioned effect of the inverter, referring to 7 described.

The inverter control 102 has the function, the detection values vuv_g and vvw_g of the AC system voltage, the detection values vuv_s and vvw_s of the output voltage of the power generator 3 , and the detection values iu and iw of the output current of the inverter 5 to use as input signals and the gate signal gate sig, which causes the inverter 5 outputs an AC power, so the difference between the voltage phase of the AC system 100 and the voltage phase of the power generator when the start command is active 5CMD is reduced to calculate and spend; and a function for calculating the phase difference Δθ between the voltage phase of the AC system 100 and the output voltage phase of the power generator used as condition for the state transition, and for outputting the calculated phase difference Δθ to the state controller 101 issue. The operation of the controller 102 is by an operating unit 10220 accomplished in which the actuation occurs only when the inverter start command 5CMD is active, as well as by another operating unit, in which there is always an operation.

In the operating unit, which operates constantly, mainly the process of determining a state variable is performed. That is, it will calculate the voltage phase of the AC system 100 , the calculation of the output voltage phase of the energy generator 3 , the calculation of the phase difference Δθ between the voltage of the AC system 100 and the output voltage of the power generator 3 , the calculation of an active power output of the inverter, the calculation of a value of a dq transformation of the output current of the inverter 5 , and an oscillation operation of a triangular wave which is a carrier for the gate signal.

On the other hand, in the operating unit 10220 the process for reducing the phase difference, in which the active power supplied by the inverter 5 to the energy generator 3 is output, depending on the phase difference Δθ is calculated, a power control and a current control depending on the active power command value, which was calculated due to this process for reducing the phase difference performed. This control is one of the characteristic features of this embodiment. In a case where the start command 5CMD is not active, the overall operation of the actuator unit 10220 reset, and the gate signal GateSig is turned off altogether.

The detailed contents of the operation of the inverter control 102 , on the basis of which the aforementioned control is achieved, will be referred to 7 described.

The voltage detection values vuv_g and vvw_g of the AC system 100 which of the voltage sensors 60uv and 60vw are detected, become a two-phase to three-phase transformation operator 10201 entered. The two-phase to three-phase transformation operator 10201 calculates from the line voltages vuv_g and vvw_g values depending on a phase voltage vu_g, vv_g and vw_g, where a voltage of the zero phase is considered zero. The calculated values expressed as phase voltages become a phase detector 10202 entered. The phase detector 10202 calculates the voltage phase θg of the AC system 100 by means of a PLL (Phase Lock Loop) control, which is a known technique, and gives it to the subtractor 10205 out.

Likewise, the output voltage detection values vuv_s and vvw_s of the power generator become 3 that of the voltage sensors 61uv and 61vw are detected as inputs to the two-phase to three-phase transform operator 10203 used. The two-phase to three-phase transformation operator 10203 calculated from the line voltages vuv_s and vvw_s depending on the phase voltages vu_s, vv_s and vw_s, with the zero phase voltage considered to be zero. The calculated values depending on the phase voltage vu_s, vv_s and vw_s are applied to the phase detector 10204 and an active power calculation unit 10208 output. The phase detector 10204 leads in the same way as the phase detector 10202 a PLL process for calculating the phase θs of the output voltage of the power generator 3 by. The calculated voltage phase θs is applied to the subtractor 10205 and a sine wave generator 10213 output.

The output current detection values iu and iw of the inverter 5 that from the current sensors 62u and 62w are detected are sent to the subtractor 10207 which computes the remaining V-phase current iv. The current detection values iu and iw and the calculated V-phase current iv are applied to the active power calculation unit 10208 and an R-β transformer 10209 output.

The active power calculation unit 10208 uses the values expressed by phase voltages vu_s, vv_s and vw_s, as well as the inverter current detection values iu, iv and iw as inputs, calculates an active power Pinv that the inverter side to the power generator 3 and outputs the calculated active power Pinv to a subtractor 10210 in the operating unit 10220 out. The active power is calculated by the sum of the products of the phase voltage with the current for the three phases.

The R-β generator 10209 uses iu, iv and iw as its input signals and performs coordinate transformation for the latter in R components iR and iβ which are components in two orthogonal axes. The R-β transformation is expressed by the following expression. [Equation 1]

The sine wave generator 10213 uses the phase θs of the output voltage of the power generator 3 As its input signal, a cosine component calculates cos (θs) and a sine component sin (θs) having θs as a phase, and outputs them to a dq transformer 10212 and a dq inverse transformer 10216 in the operating unit 10220 out. The output id of the dq inverse transformer 10216 represents an active current component and iq represents a reactive current component. The actuation in the dq inverse transformer 10216 is expressed by the following expression. [Equation 2]

The active current id is put into a subtracter together with an active current command value Idref, which will be described later 10213 entered. The subtractor 10213 gives the difference between these to a current controller 10213 in the operating unit 10220 out. The reactive current iq, together with a reactive current command value, which is zero, in a subtractor 10214 entered. The subtractor 10214 gives a difference between these to the current control 10215 in the operating unit 10220 out.

A carrier generator 10219 calculates a triangular wave Tri, which is a carrier for the calculation of the gate signal for the inverter 5 is, and outputs the triangular wave Tri to a PWM actuator 10218 in the operating unit 10220 out.

The operation of the operating unit 10220 will now be described. In the operating unit 10220 a power control operation is performed, which is a phasing of the power generator 3 by the inverter incorporating the characteristic features of this embodiment.

The phase difference Δθ between the voltage phase of the AC system 100 and the phase of the output voltage of the power generator 3 that is from the subtractor 10205 is calculated in the phase adjuster 10206 entered. The rotor of the energy generator 3 receives an acceleration energy from the low pressure side turbine 23 and the inverter 5 , If the phase difference Δθ is positive, it means that the phase of the output voltage of the power generator 3 the voltage phase of the AC system 100 lags. By outputting a positive real power from the inverter 5 to the energy generator 3 if Δθ is positive, it is possible to use the rotor of the energy generator 3 to accelerate and so the phase of the output voltage of the power generator 3 to put forward. The phase adjuster 10206 performs Δθ a proportional / integral control operation in which the gain is positive, and outputs an active power command value Pref, which is the calculation result of the subtractor 10210 is.

The subtractor 10210 calculates the difference between the above-mentioned active power command value Pref and the active power calculation value Pinv and outputs it to an active power control 10211 out. The active power control 10211 calculates an active current command value Idref, so that the difference between the above mentioned active services is reduced. In particular, the active power control calculates 10211 the active current command value Idref using a proportional / integral control and input of the active power difference values in the latter. The active power control 10211 gives the active current command value Idref to the subtractors 10213 out.

An active current deviation that is generated by the subtractor 10213 is calculated, and a reactive current deviation from the subtractor 10214 is calculated into the current control 10215 entered.

The current control 10215 calculates voltage command values vd and vq of the inverter 5 so that the above-mentioned current deviations are reduced. In particular, the controller 10215 Equipped with two proportional / integral controls, the active current deviation enters the first proportional / integral control to calculate the d-axis voltage command value vd and gives the reactive current deviation to calculate the q-axis voltage command value vq into the second proportional / integral Regulation. The calculated voltage command values vd and vq are applied to the dq inverse transformer 10216 entered.

The dq reverse transformer 10216 uses the outputs of the power control 10215 and the sine wave generator 10213 as input signals and, depending on Equation 3, performs a dq inverse transformation to compute an R-axis component vR and a β-axis component vβ of the voltage command values. [Equation 3]

The voltage command values vR and vβ are from a two-phase to three-phase transformer 10217 converted into three phase amounts vu, vv and vw. The expression for the transformation is expressed by Equation 4. [Equation 4]

The command values vu, vv and vw and the carrier Tri are put into the PWM operator 10210 which inputs the gate signal GateSig of the IGBT device in the inverter 5 by comparing the magnitudes of the carrier Tri and the voltage command values with each other.

If the start command 5CMD for the inverter 5 is active, the gas turbine power generation system, the energy for accelerating the rotor of the power generator 3 corresponding to the phase difference Δθ from the inverter 5 produce.

In this embodiment, the gas turbine power generation system is 1 a dual shaft gas turbine power generation system. However, the same advantageous effects can also be achieved in a single-shaft gas turbine power generation system in which the power generator 3 with the wave 24 is connected, with which the high-pressure side turbine 23 is connected, and in which no low-pressure side turbine is provided. In this case, since the numbers of revolutions of the high-pressure side turbine 22 and the energy generator 3 are equal to each other, N_LPT replaced by H_LPT, and the speed sensor 64 for detecting the number of revolutions N_LPT is not necessary.

In this embodiment, the gas turbine power generation system will be described as an example. However, if it is problematic to bring the power generator into a state in which the power generator can be connected to the system during startup, this problem can be solved with a procedure similar to that of the above embodiment, when the power generation system such is where the power generator is powered by a power source connected to the system. Therefore, by reducing the phase difference between the power generator and the system assisting to adjust the phase of the power generator by a power converter connected directly in parallel with the power generator, it is possible to achieve the advantageous effect of reducing a startup time of the power generation system Generating an overcurrent with regard to the connection is avoided. This is because an electrical response is usually faster than a mechanical response of the energy source.

As another power source, for example, steam turbines, water wheels, diesel engines, piston engines and windmills may be considered. These can be provided with the same advantageous effects as those of the present embodiment. Further, since the torque of the shaft of the power generator is controlled to a lower value, the effect of reducing the starting time for the same inverter size can be enhanced. For example, the control described in this embodiment can achieve more advantageous effect when used in a twin-shaft gas turbine power generation system in which a heavy rotating part such as a compressor is isolated than when it is carried out in a single-shaft gas turbine. in which the rotary member is connected to the same shaft as the power generator.

A gas turbine power generation system generally has a shorter startup time compared to a power generation system with a different power source, and is therefore expected to make important contributions to system stabilization in the introduction of renewable energy due to its short startup. When the power source of the power generation system of this embodiment is a gas turbine, in addition to the above-mentioned effects, the effect of improving a response speed to fluctuations in the system voltage and a synergistic effect of reducing an environmental load by improving the fuel efficiency during the starting operation can be achieved; while the starting time of the power generation system is further reduced.

Further, the double-shaft gas turbine has the problem that the adjustment of the phase difference between the system voltage and the terminal voltage of the power generator is particularly difficult because the driving force of the second turbine is indirectly controlled by the exhaust gas of the first turbine. The control described in this embodiment can directly electronically control the rotor torque for reducing the phase difference between the system voltage and the output voltage of the power generator, even if the power source of the power generation system is a double-shaft gas turbine, and thus can achieve the advantageous effect that the adjustment is easy.

In addition, the double-shaft gas turbine also has a problem of longer startup time as compared with the single-shaft gas turbine, because the fuel injection and the intake air amount adjustment are performed mechanically, and it is necessary during these operations to convert the exhaust gas amount into a system connection state. The control performed in this embodiment leads to the further advantageous effect of reducing the startup time in a power generation system having a multi-wave gas turbine having two or more shafts as compared with a power generation system using the single-shaft gas turbine as its power source.

In this embodiment, the inverter is used as a rectifier in some cases. Thus, when a device is referred to as an inverter, its power conversion function is not limited to converting DC to AC. In certain combinations with other devices, the inverter may also be used as an AC / AC converter, such as a transformer transformer, and may be replaced by another power conversion unit. These power conversion units are therefore collectively referred to as inverters in some cases.

The DC power supply connected to the inverter may include a secondary battery, such as a storage battery, another power generator connected via a rectifier, or a DC power supply, the power from a rotary machine connected to the shaft of the compressor, as in another embodiment is used, or may be a combination of the examples mentioned.

The starter motor 4 can be connected to a different power supply, different from the AC system, as in 18 4, or instead, a unit other than the starter motor, for example, a compressor for supplying compressed air, may be provided as a starter of the gas turbine.

The breaker is a unit for establishing and breaking the electrical signal connection, and may for example be implemented in any form, for example as a switch or as a protection circuit.

Between the inverter 5 and the energy generator 3 may be a second breaker to disconnect the power generator 3 and the inverter 5 be provided from each other. In this case, to carry out a control, which is the phase difference of the power generator and the system using the inverter 5 reduced, the second breaker actuated before the breaker 30 is pressed.

In this embodiment, the starter motor 4 an induction machine working directly with the AC system 100 connected is. The starter motor 4 however, it may be a synchronous machine or an induction machine that is powered by an inverter 2000 is controlled by a diode rectifier, as in 17 is shown.

The starter motor 4 can the wave 24 in 2 via a torque converter 3000 drive in which a transmitted torque is controlled depending on a difference in the number of revolutions of the shafts, as in 17 is shown.

The starter motor 4 is a permanent magnet motor in this embodiment. Another synchronous machine, such as a DC excitation synchronous machine, can achieve the same advantageous effects.

In this embodiment, the starter motor 4 designated rotary machine used as a motor of this embodiment and is therefore used as a starter motor 4 designated. The term starter motor 4 However, does not preclude its use for other purposes such as power generator, and therefore the starter motor 4 Also referred to as a rotary machine, instead of calling it a starter motor.

In the gas turbine power generation system 1 According to this embodiment, the starter motor 4 can also be actuated after the power source has been ignited, and can with the regulation of the inverter 5 be connected when a phase adjustment of the power generator voltage is performed.

In the gas turbine power generation system, it takes time for the phase of the output voltage of the power generator 3 and the phase of the voltage of the AC system 100 to be adjusted by mechanical inputs. Further, in the case of a twin-shaft gas turbine, the driving force of the low-pressure side turbine needs to be indirectly adjusted by the exhaust gas of the high-pressure side turbine, so that time is required for adjusting the phase of the power generator. According to this embodiment, it is possible to directly control the driving force of the power generator to a higher speed with power, thus enabling the higher-speed phase adjustment to be performed.

In the case of the double-shaft gas turbine, for example, it takes several minutes from the start of the operation of the starter motor to the time when the shaft reaches a predetermined number of revolutions, and then the number of revolutions of the shaft is adjusted by a turbine system so that the number of revolutions of the shaft a target revolution number is stabilized, and synchronization with the AC system is established. If the power generator is controlled to be operated by electrical input signals and the phasing of the low pressure turbine shaft and the power generator is performed immediately after the shaft reaches the predetermined number of revolutions, the phasing will only take a few seconds. It is therefore possible to establish a state in which the numbers of revolutions of the low-pressure shaft and the power generator are already fully set before the setting of the revolution numbers of the shaft of the high-pressure turbine and the compressor in a turbine system begins.

After the energy generator 3 and the AC system 3 have been synchronized and the breaker 30 has been closed, it is possible to effect the connection of the system and the control of the power generation amount by adjustment by means of the gas turbine. When this condition is reached, the inverter can 5 being stopped. If the inverter 5 is stopped, it is desirable to have a compensation power of the inverter 5 gradually reduce and the inverter 5 to stop.

As described above, according to the first embodiment of the invention, it is possible to more rapidly establish the state for operating the breaker in the gas turbine power generation system with the inverter as compared with a conventional gas turbine power generation system, and thus reducing the startup time of the gas turbine power generation system 1 to reach.

By starting the power supply from the power converter 5 to the energy generator 3 From a state in which the number of revolutions of the rotor of the power generator is stopped, the increase in the number of revolutions can be supported as a whole, so that the advantageous effect of reducing the starting time of the power generation system is further enhanced.

Second embodiment

The second embodiment of the present invention will be referred to 8th described. Compared with the first embodiment, the components having the same function are given the same reference numerals, and redundant description parts are avoided.

A difference to that in 1 shown first embodiment is that an AC power source of an inverter 5A which is connected to the power generator instead of the DC power supply 7 one with the shaft 24 and an inverter 5B connected rotary machine 6 is. By this construction, it is possible to one for the synchronization of the power generator 3 provide required power through the gas turbine itself. The unit price per kW of a storage battery to provide the DC power supply 7 is usually more expensive than that Unit price of an inverter or motor. Thereby, by using the structure of the second embodiment, the starting operation time of the gas turbine power generation system can be reduced inexpensively.

In this embodiment, a rotary machine connected to the shaft mechanically connected to the compressor and one with the rotary machine 6 connected power converter 5B provided. The power converter 5B is with a DC connection of the power converter 5A instead of the DC power supply 7 connected, and to the DC terminal, a capacitor is connected. The control 10 performs a control such that when the number of revolutions of the rotor of the power generator after the start of the fuel combustion in the combustion chamber exceeds a predetermined number, the controller controls the power converter 5B and the power converter 5A starts and, after the terminal voltage of the power generator and the voltage of the AC system have been synchronized with each other, the controller the breaker 30 actuated.

As the main circuit of both the inverter 5A as well as the inverter 5B is a 2-stage inverter with the same structure as that of the inverter 5 provided according to the first embodiment. The DC circuit connections P of the inverters 5A and 5B are connected together and their DC circuit terminals N are also connected together. Between the terminals P and N is a capacitor 9 provided for smoothing the DC voltage. These inverters 5A and 5B are not limited to those with the structure shown. Alternatively, to achieve a desired phase adjustment effect, an AC / AC converter may be used instead.

The terminal voltage of the capacitor 9 is through a voltage sensor 67 which detects its detection value, ie a DC capacitor voltage detection value vdc to the controller 10AB outputs. Output currents of the inverter 5B be from current sensors 65u and 65w detects which respective detection values iu2 and iw2 to the controller 10AB output.

The rotary machine 6 is a permanent magnet energy generator. AC connections U, V and W of the inverter 5B are with the stator winding of the rotary machine 6 connected. Output voltages of the rotary machine 6 be from voltage sensors 66uv and 66vw detected, the respective output detection values vuv_m and vvw_m to the controller 10AB output.

The structure of the controller 10AB is referred to 9 described.

The control 10AB is through a state control 101ab , an inverter control 102ab , and the turbine control 103 in the same way as in the controller 10 of the first embodiment. The turbine control 103 is the same as that of the first embodiment. Because the inverter 5B to the first embodiment, the processes in the state control and the inverter control are changed.

An actuation flowchart in state control 101ab is referred to 10 described.

As in the first embodiment, the controller retains 10AB a standby state S1, until the start command StartCMD for the gas turbine power generation system 1 is entered.

When the start command StartCMD is input, the state control changes 101ab the state in a breaker operating state S2, and the command 31CMD for the breaker 31 is changed from open to close.

If the breaker 31 is actuated by the starter motor 4 a torque on the shaft 24 exercised, and the number of revolutions increases slowly.

When the number of revolutions N_HPT of the high-pressure side turbine 22 does not constitute a predetermined value N_Fire or less, no state transition is performed. When N_HPT exceeds N_Fire, the combustion start command is issued 21CMD the gas turbine 2 activated, and the breaker 31 is switched from the close command to the open command. After the above commands 21CMD and 31CMD changed, the state changes to a state S3.

By igniting the combustion chamber 21 the number of revolutions of the high-pressure side turbine increases 22 at. When the number of revolutions N_HPT exceeds a second predetermined value N_min, which is greater than the predetermined N_Fire, the controller activates 10AB a start command 5B_CMD to start the inverter 5B ,

The inverter 5B represents a power output for the rotary machine 6 such that the direct current detection value vdc coincides with a value vdcref which corresponds to a setpoint value vdcref. DC voltage of the inverter 5A equivalent. More precisely, the inverter represents 5B the to the rotary machine 6 power to be output to a negative value when the DC voltage detection value vdc is smaller than vdcref, so that a power for charging the capacitor 9 from the rotary machine 6 is obtained.

When the DC capacitor voltage detection value vdc exceeds a predetermined value Vdc_min, the control changes 10AB the state to a state S5, in which the start of the inverter 5B finished.

The predetermined value Vdc_min is preferably set to approximately 95% of the command value vdcref. By setting the predetermined value to this value, it can be expected that approximately one target DC voltage in the inverter 5A is fed when the state is switched to the state S5, so that the start of the inverter 5A is prepared.

Subsequently, as in the first embodiment, when the number of revolutions N_LPT of the low-pressure side turbine is between the predetermined values N_min and N_max, the inverter 5A started, and a power output of the inverter 5A to the energy generator 3 is set so that a phase of the voltage of the power generator 3 the voltage phase of the AC system 100 is approximated.

Now the operation of the inverter control 102ab described.

The inverter control 102ab is through a controller 102A for the inverter 5A and a controller 102B educated. The control 102A performs the same operations as the inverter control 102 from that described in the first embodiment, so that their description can be omitted.

The operation of the controller 102B for the inverter 5B which is one of the features of this embodiment will be referred to 11 described.

The control 102B uses that of the state controller 101ab , issued start command 5B_CMD for the inverter 5B , the DC capacitor voltage detection value vdc, the detection values vuv_m and vvw_m of the output voltages of the rotary machine 6 and the detection values iu2 and iw2 of the output voltages of the inverter 5B as input signals and gives a gate signal GateSigB of the inverter 5B out. The role of the inverter 5B According to this embodiment, it is the inverter 5A to supply a constant DC capacitor voltage, and the controller 102B calculates the gate signal GateSigB so that the DC capacitor voltage is adjusted.

The control 102B is by an operating unit 102B20 formed, which works only when the start command 5B_CMD of the inverter 5B is active, as well as by another operating unit. The further operation unit performs operations for calculating the phase of the output voltage of the rotary machine 6 and the active current component id2 and a reactive current component iq2, which in the output currents of the inverter 5B are included.

The following describes a specific flow of signals.

The output voltage detection values vuv_m and vvw_m of the rotary machine 6 become in a two-phase-to-three-phase transformation operator 102B03 entered. The two-phase to three-phase transformation operator 102B03 calculates values depending on phase voltage vu_m, vv_m and vw_m from line voltages vuv_m and vvw_m, whereby a zero phase voltage is considered as zero.

The values depending on the phase voltage vu_m, vv_m and vw_m are in the phase detector 102B04 entered. The phase detector 102B04 performs a PLL operation for the values input thereto to calculate the phase voltage phase θm. The phase voltage phase θm is applied to a sine wave generator 102B13 output. The sine wave generator 102B13 outputs a cosine component cosθm and sinθm, each having the phase θm, to a dq transformer 102B12 and to a dq inverse transformer 102B16 in the operating unit 102B20 ,

The detection values iu2 and iw2 become a subtractor 102B07 entered. The subtractor 102B07 calculates a v-phase current value iv2.

The current detection values iu2, iv2 and iw2 become in an R-β transformer 102B09 entered. The R-β transformer calculates an R component iR2 and a β component iβ2 of the output currents of the inverter 5B and gives this to the dq transformer 102B12 out. An operation in the R-β transformer 102B09 is the same as the operation expressed by Equation 1 in the first embodiment. The dq transformer performs a dq transformation for iR2 and iβ2 with a sine wave signal cosθm and sinθm received from the sine wave generator 102B13 and gives to subtractors 102B13 and 102B14 Values id2 and iq2 obtained by the transformation. An operation of the dq transformer 102B12 is the same as that expressed by Equation 2 in the first embodiment.

The subtractor 102B13 calculates the difference between an active current command value Idref2, that of a voltage control 102B11 , which will be described later, and id2, and outputs the calculated difference to a current controller 102B15 in the operating unit 102B20 out.

The subtractor 102B14 calculates a difference between a reactive current command value Iqref having the value zero and iq2, and outputs the calculated difference to a current controller 102B15 in the operating unit 102B20 out.

The carrier generator 102B19 outputs a carrier Tri, which is a carrier for generating the gate signal of the inverter 5B is, to a PWM operator 102B18 in the operating unit 102B20 ,

The operating unit 102B20 will now be described. Operation in the operating unit 102B20 will only be executed if the start command 5B_CMD for the inverter 5B is active. If 5B_CMD is not active, the entire operation of the actuator unit 102B20 reset and gate signal GateSigB is turned off altogether.

The DC capacitor voltage detection value vdc and the DC capacitor voltage command value Vdcref are input to the subtractor 102B10 entered. The subtractor 102B10 gives a difference between these to the DC voltage control 102B11 out.

The DC voltage control 102B11 includes a proportional / integral control, which the Wirkstrombefehlswert Idref2, by the inverter 5B is calculated in such a manner that an input voltage deviation is reduced, and outputs the calculated value to the subtractor 102B13 out.

The difference between the active current command value Idref2 and the active current id2 and the difference between the reactive current command value Iqref and the reactive current iq2 is applied to the current control 102B15 entered. The current control 102B15 performs the same operations as the power control 10215 of the first embodiment for calculating the current command values vd2 and vq2. vd2 and vq2 are connected to the dq transformer 102B16 output.

The dq inverse transformer 102B16 performs the same operations for the voltage command values vd2 and vq2 as the dq inverse transformer 10216 for calculating the R and β components vR2 and vβ2 of the voltage command values and outputs the calculated values to the two-phase to three-phase transformer 102B17 out.

The two-phase to three-phase transformer 102B17 also performs the same operations as the two-phase-to-three-phase transformer 10217 for vR2 and vβ2 to calculate the command values vu2, vv2 and vw2 of the three phases and outputs the calculated values to the PWM operator 102B18 out.

The PWM operator 102B18 uses the voltage command values vu, vv, and vw and the carrier Tri, which is from the carrier calculator 102B19 is outputted as its input signals and computes the gate signal GateSigB by comparing the magnitudes of the voltage command values and the carrier Tri with each other, as well as the PWM operator 10218 does.

Through the above operations can then, when the start command 5B_CMD for the inverter 5B is active, the inverter 5B controlling the turning on and off of the IGBT device in such a manner that the DC capacitor voltage detection value vdc is brought closer to the command value vdcref, and so can provide a constant DC voltage to the inverter 5A feed.

In this embodiment, the gas turbine power generation system will be described as a dual shaft gas turbine power generation system. However, the same beneficial effects can also be achieved by single-shaft gas turbine power generation systems. In this case, since the number of revolutions of the high-pressure side turbine 22 and the number of revolutions of the power generator 3 are equal, N_LPT replaced by N_HPT, and the speed sensor 64 is not needed.

As described above, in the second embodiment of the present invention, in the gas turbine power generation system having the inverter, it is possible to more quickly achieve the necessary condition for operating the breaker as compared with conventional gas turbine power generation systems, so that the startup time of the gas turbine power plant can be increased. power generation system 1 can be reduced. Furthermore, that of the inverter 5A to the energy generator 3 forwarded power can be provided by the gas turbine power generation system itself, and an expensive DC power supply is not needed. The starting time of the gas turbine power generation system can therefore be reduced in a cost effective manner.

In this embodiment, the rotary machine is 6 not only a starter motor that is driven when the number of revolutions is zero, but also works when the gas turbine rotates at high speed. The rotary machine 6 is therefore preferably a suitable motor generator for this purpose.

In this embodiment, the rotary machine 6 and the starter motor 4 Permanent magnet motors. However, other synchronous machines, such as DC excitation synchronous machines, can achieve the same advantageous effects.

As in 19 As illustrated by the use of a DC power supply of the first embodiment in common with this embodiment, it becomes possible to reduce the capacity of the expensive DC power supply to a small value. In addition, by enhancing the effect of reducing the startup time and ensuring a performance buffer, it becomes possible to increase the reliability.

Third embodiment

The third embodiment of the present invention will be referred to 12 described. A difference between this embodiment and the second embodiment of the present invention is that the function of the starter motor 4 with the help of the rotary machine and the inverter 5A and 5B is achieved, so the rotary machine 6 both as a unit for increasing the number of revolutions of the compressor 20 during the startup process of the gas turbine power generation system as well as a high speed phase adjustment unit for the power generator 3 is used. According to this embodiment, the starter motor 4 be omitted, so that the system components can be simplified.

In this embodiment, the inverter is 5A both with the power generator side and with the AC system side of the breaker 30 connected, and a switching unit (a breaker 31 and a breaker 32 in 12 ) for establishing and interrupting these two connections and switching the connection state is provided. The controller performs control such that before the start of fuel combustion in the combustion chamber, the controller controls the inverter 5A with the AC system side of the breaker 30 connects, and if the number of revolutions of the power generator rotor exceeds a predetermined value after the start of the fuel combustion in the combustion chamber, the controller, the connection of the inverter 5A with the AC system side of the breaker 30 interrupts and the inverter 5A with the power generator side of the breaker 30 combines.

This switching unit preferably has the function, the power generator side and the AC system side of the breaker 30 to transfer to a state in which these two are separated, and to a state in which both are connected.

The use of the rotary machine 6 also as a starter motor 4 can be achieved by the of the state control of the gas turbine power generation system 1 a new state is added to the controlled boot sequence and a new actuation function to toggle the control function of the inverters 5A and 5B is supplemented. The details of the third embodiment will be described below mainly with reference to the differences from the second embodiment. The elements having the same function are denoted by the same numbers as in the first and second embodiments, and a redundant description of the latter is avoided.

12 shows a main circuit structure of the gas turbine power generation system 1 of the third embodiment of the present invention. Differences in the main circuit structure to the second, in 8th illustrated embodiment are that the starter motor 4 deleted and that the AC terminals U, V and W of the inverter 5A over the breaker 31 with the AC system 100 connected and over the breaker 32 with the energy generator 3 ,

According to the startup sequence described later, the inverters receive 5A and 5B over the breaker 31 Power from the AC system 100 and provide a torque that increases the number of revolutions of the compressor until the gas turbine fuel ignites, and after the ignition of the fuel of the gas turbine becomes the interrupter 31 opened and the breaker 32 operated, so that a power to adjust the phase of the rotary machine 6 provided energy generator is received. These actions are due to commands of the controller 10AB2 carried out.

Referring to 13 becomes the structure of the controller 10AB2 described.

The control 10AB2 is made up of a state control 101AB2 performing a state control operation of an inverter controller 102AB2 which is a process for controlling the inverter 5A and 5B performs, and the controller 103 which performs the operations for controlling the fuel valve and the IGV of the gas turbine. The operation of the gas turbine control is the same as that in the first and second embodiments and will be described by the same reference numerals.

The state control 101AB2 is different from state control 101ab in that it outputs a signal AVR_FLG indicating a switching of the control modes of the inverters 5A and 5B causes, in addition to the output signals of the state control 101ab , The inverter control 5A and 5B switches between objects to be controlled by the signal AVR_FLG. In particular, it is determined which of the inverters is based on the signal AVR_FLG 5A and 5B performs a DC capacitor voltage control. The inverter 5A regulates the phase adjustment of the energy generator 3 when performing no DC capacitor voltage control. The inverter 5B controls the number of revolutions of the compressor 20 if it does not perform DC capacitor voltage regulation.

The state control process of state control 101AB2 is referred to 14 described.

When the start command StartCMD of the gas turbine power generation system 1 becomes active, the state control switches 101AB2 a state from a stop state S1 to an operating state S2 of the breaker 31 around. At this time, the command becomes 31CMD for the breaker 31 changed from open to close, leaving the breaker 31 is pressed.

Then the start command 51CMD to start the inverter 5A activated and AVR_FLG is activated so that the inverter 5A controls the DC capacitor voltage.

The inverter 5A controls one of the AC system 100 received power through a controller described later 102A2 such that a DC capacitor voltage matches a command value vdcref.

The state control 101AB2 compares the magnitude of the DC capacitor voltage detection value vdc input thereto with a predetermined value Vdc_min, and changes the state to a state S3 in which the start of the inverter 5A is terminated and the inverter 5B is started when Vdc_min <vdc.

At this point, the inverter control generates 102B2 the start command 5B_CMD for the inverter 5B and thus starts the inverter 5B ,

The inverter control 102B2 receives as input signals 5B_CMD and AVR_FLG by a controller 102B2 which will be described later from the state controller 101AB2 and toggles the current command value so that the number of revolutions of the compressor 20 is regulated when AVR_FLG is active, and the regulation of the DC capacitor voltage is performed when AVR_FLG is not active.

In state S3, the inverter controls 5B one on the rotary machine 6 torque value to be transmitted so that the number of revolutions of the compressor 20 matches the command value because the inverter 5B the number of revolutions regulates.

The number of revolutions of the compressor 20 is due to the torque from the inverter 5B elevated. The state control 102AB2 compares the magnitudes of the detection values N_HPT of the number of revolutions of the high-pressure side turbine and a predetermined value N_min2 with each other, activates the start command 21CMD to cause the gas turbine 2 Fuel burns when N_HPT> N_min2, and changes state to a combustor firing state S4.

If the start command 21CMD is active, the combustion chamber begins 21 the gas turbine 2 with the burning of fuel, and the high-pressure side turbine 22 receives torque due to the expansion force generated due to combustion. Therefore, the gas turbine 12 generate a driving force itself.

The state control 101AB2 then switches the start commands 5A_CMD and 5B_CMD the inverter 5A and 5B on inactive and thus stops the inverter 5A and 5B , At the same time AVR_FLG is switched to inactive, so that the function of the inverter 5A is switched to torque control in the starting process, and the function of the inverter 5B on DC capacitor voltage regulation.

Also the open / close command for the breaker 31 is switched from opening to closing, so that the inverter 5A and the DC system 100 be separated from each other. The condition is determined by the combustion chamber Ignition state S4 transferred to a state S5, in which the breaker 31 is open.

To start the phasing of the power generator 3 through the inverter 5A switches the state control 101AB2 the open / close command 32CMD for the breaker 32 from open to close, switches the start command for the inverter 5B to active and changes the state to a state S6 in which the breaker 32 is closed and the inverter 5B started.

If the breaker 32 is pressed, the AC terminals U, V and W of the inverter 5A with the stator winding of the power generator 3 connected so that a connection is made, which is similar to that in the first and second embodiments of the invention.

Because AVR_FLG is inactive, the controller stops 101B2 of the inverter 5B the output voltage of the rotary machine 6 such that the DC capacitor voltage matches the command value. The action of the inverter 5B while AVR_FLG is inactive, the same action as that described in the second embodiment of the present invention.

As in the second embodiment, the state controller switches 101AB2 when the DC capacitor voltage detection value vdc exceeds Vdc_min, the start command 5A_CMD for the inverter on active to the inverter 5A to start. The inverter 5A controls the power output to the power generator 3 such that the phase difference between the phase of the AC system 100 and the phase of the energy generator 3 from the controller 102A2 is reduced.

The state control 101AB2 compares an amount │Δθ│ of the above-mentioned phase difference and a decision value Δθmax with each other and changes the command 30CMD to open / close the breaker from open to close when the amount is less than or equal to the decision value, so that the gas turbine power generation system 1 with the AC system 100 is connected.

As described above, the controller controls 101AB2 the inverters 5A and 5B and the breakers 31 and 32 and thus makes it possible for the rotary machine 6 to also take over the function of the starter motor.

The control 101A2 for performing an operation of an operation of the control of the inverter 5A is referred to 15 described.

In order to avoid redundant parts of description, mainly a difference to the controller 102A of the second embodiment of the present invention.

The difference between the controllers 102A and 102A2 is that AVR_FLG from the state control 101AB2 is input, and the DC capacitor voltage detection value vdc is used as additional input signals, and a subtractor 10230 which calculates the difference between the DC capacitor voltage command value and the above-mentioned detection value vdc as a subtractor, and further voltage control 10231 and a switch 10232 are provided.

When AVR_FLG is inactive, regulation of the phasing of the power generator becomes 3 in the same way as in the controller 102A carried out. When AVR_FLG is active, the DC capacitor voltage is regulated.

More specifically, the operation of the phase adjuster 10206 is stopped, and it is formed by a proportional / integral control voltage regulation 10231 performed when AVR_FLG is active. AVR_FLG will also be in the switch 10232 entered. The desk 10232 gives the output signal of the voltage control 10231 as the active current command value to the subtractor 10213 off when AVR_FLG is active and outputs the active current control output 10211 as the active current command value to the subtractor 10213 off if AVR_FLG is inactive.

Due to the above structure, the controller performs 102A2 when AVR_FLG is active, a proportional / integral control operation for the deviation between the DC capacitor voltage detection value vdc and the DC capacitor voltage command value Vdcref and determines its output as the active current command value for the inverter 5A so the inverter 5A is controlled so that the DC capacitor voltage matches the command value.

Next is the controller 102B2 for carrying out a process of controlling the inverter 5B Referring to 16 described.

In order to avoid redundant description parts, a main difference becomes the control 102B2 of the second embodiment of the present invention.

The difference between the controller 102B and the controller 102B2 is that AVR_FLG from the state control 101AB2 and the detection value N_HPT of the number of revolutions of the high-pressure side turbine are used as additional input signals, and that a subtractor 10240 calculating the difference between the detection value N_HPT of the number of revolutions of the high-pressure side turbine and a command value N_HPTref of the number of revolutions of the high-pressure side turbine which is a constant value as an operator; a torque calculator 10241 , which is a torque which is supplied by the inverter 5B the rotary machine 6 is to be output, calculated; a speed control 10242 which receives the deviation between the above-mentioned revolution numbers as an input signal and performs proportional / integral control such that such a torque command value is calculated that the revolution number of the high-pressure side turbine is made to coincide with the command value; a subtractor 10243 which indicates a deviation of the torque command value, that of the speed control 10242 was calculated, and that of the above torque calculator 10241 calculated and from the inverter 5B on the rotary machine 6 applied torque calculated; a torque control 10244 representing the output signal of the subtractor 10243 is used as its input signal and executes an active current command value for carrying out the proportional / integral control in such a way that that of the inverter 5B to the rotary machine 6 output torque is made in accordance with the command value; and a switch which receives AVR_FLG as an input and the output of the torque controller 10244 as the active stream command value to the subtractor 102B13 outputs when AVR_FLG is active and the output of the voltage control 102B11 as the active stream command value to the subtractor 102B13 outputs when AVR_FLG is inactive.

With the above construction, the controller can 102B2 the inverter 5B in such a way that the number of revolutions of the high-pressure side turbine coincides with the command value when AVR_FLG is active, and the power phasing power of the power generator 3 for the inverter 5A by keeping the DC capacitor voltage constant when AVR_FLG is inactive.

In this embodiment, the gas turbine power generation system 1 as a double shaft gas turbine power generation system. However, a single-shaft gas turbine power generation system having the same advantageous effects may be used. In this case, N_LPT can be replaced by N_HPT, and the speed sensor 64 is not needed because the high pressure side turbine 22 and the rotor of the power generator 3 turn with the same number of revolutions.

In this embodiment, the DC capacitor voltage during startup of the gas turbine power generation system by the inverter 5A controlled to a constant value, and it is therefore not necessary that in the stator winding of the rotary machine 6 when starting the inverter 5B Induction voltage is generated. The rotary machine 6 does not have to be a synchronous machine but can be an induction machine.

As described above, in the gas turbine power generation system having the inverter according to the third embodiment of the present invention, it is possible to set the state for operating the breaker 30 faster to achieve compared to conventional gas turbine power generation systems, so that the startup time of the gas turbine power generation system 1 is reduced.

Furthermore, that of the inverter 5A for the energy generator 3 provided power from the gas turbine power generation system itself, and an expensive DC power supply is not necessary. Therefore, the reduction of the startup time of the gas turbine power generation system can be achieved in a cost effective manner.

Furthermore, the starter motor 4 not necessary, since the function of increasing the number of revolutions of the high-pressure side turbine during the starting process of the gas turbine from the rotary machine 6 and the inverters 5A and 5B can be taken. The main circuit structure of the gas turbine power generation system 1 can be simplified.

The switching unit in this embodiment is not limited to the structure shown in FIG 12 is shown. For example, at a branch point of the inverter 5 , the energy generator 3 and the AC voltage 100 a device may be provided which switches each of the connections. Furthermore, more interrupters between the breaker 30 and the energy generator 3 and between the breaker 30 and the inverter 5 be provided. If such switching units are used, a connection relationship between the AC system becomes 100 , the energy generator 3 and the power converter 5 in the same way as that performed in this embodiment control method described.

Fourth embodiment

In the third embodiment, the rotary machine 6 from a power from the AC system 100 driven to increase the number of revolutions of the high pressure side turbine. Instead, in this embodiment, as in 20 shown, another power generator via a rectifier or a power supply, such as a storage battery, with a DC range between the inverters 5A and 5B connected, from which power is provided. This is an effective construction in an environment where power for the starter motor can not be recovered from the system.

In the structure of this embodiment, power of the DC power supply is rotated to rotate the starter motor 9 first a start of the inverter 5B carried out. At this time, the inverter will be 5A not operated or an output command for the latter is zero, and if present, the breaker 32 open. After igniting the gas turbine 2 become the inverter 5B and the DC power supply 9 stopped. When the energy generator 3 reaches a predetermined number of revolutions or more, it will switch the inverter 5 started, the breaker 32 is closed, if any, and the inverter 5 is regulated so that the phase difference between the voltage of the power generator 3 and the voltage of the AC system using the power from the rotary machine 6 is reduced.

An electrical power supply for driving the rotary machine 6 can be between the inverter 5 and the energy generator 3 , as in 21 be shown, provided, or between the inverter 5B and the rotary machine 6 although this is not shown. In the former case, the breaker 32 needed. The control process is the same as that in the FIG 20 shown construction.

Fifth embodiment

23 shows the exemplary structure of a power generation system implementing this embodiment. In this embodiment, when starting the inverter 5 supplied power from the AC system 100 relative to the phase difference between the voltage of the energy generator 3 and the voltage of the AC system 100 to reduce. Since a DC power supply or a high-speed motor generator as a source for providing electric power for phase adjustment is unnecessary, this structure is advantageous in terms of size and cost. Furthermore, this structure is advantageous because no separate power generator is needed on the power generation system side, since a power provided to a starter of the power source is from the AC system 100 can be obtained.

A controller for establishing the voltage balance and the phase difference balances between the AC system 100 and the energy generator 3 , and a unit for controlling by the breaker 30 and the breaker 32 flowing power, for example, one with the inverter 5 provided variable resistance, are needed.

When starting the power generation system 1 However, this is the relationship between the inverter 5 , the energy generator 3 and the breaker 30 , which is one of the features of this embodiment, substantially of the same kind as in the third embodiment. The content of the control by the controller 10 indicating the phasing of the energy generator 3 is the same as the control processes of the power generation system and the inverter 5 in the third embodiment.

List of reference numbers

• 1 ... gas turbine power generation system, 2 ... gas turbine, 3 ... energy generator, 4 ... starter motor, 5 . 5A . 5B .... inverters, 5 m . 5n . 5o . 5p . 5q . 5r . 5s . 5t . 5u . 5v . 5w . 5x ... IGBT devices, 5a . 5b . 5c . 5d . 5e . 5f ... diode, 7 ... DC power supply, 5g . 5h . 9 ... DC capacitor, 10 . 10AB . 10AB2 ... control, 20 ... compressor, 21 .... combustion chamber, 22 ... high pressure side turbine, 23 ... low pressure side turbine, 24 . 25 ... Wave, 26 ... IGV, 27 ... fuel valve, 30 . 31 . 32 ... breakers, 60uv . 60vw . 61uv . 61vw . 66uv . 66vw . 67 ... voltage sensor, 62u . 62w . 65u . 65w ... current sensor, 63 . 64 ... speed sensor, 100 ... AC system, 101 . 101ab . 101AB2 ... state control, 102 . 102ab . 102AB2 ... inverter control, 103 ... gas turbine control, 102A . 102A2 ... control for the inverter 5A . 102B . 102B2 ... control for the inverter 5B . 201 . 210 . 270 . 271 ... Pipe, 10201 . 10203 . 103B03 ... two-phase to three-phase transformer, 10202 . 10204 . 102B04 ... phase detector, 10213 . 102B13 ... sine wave generator, 10208 ... active current calculator, 10209 . 102B09 ... R-β transformer, 10212 . 102B12 ... dq transformer, 10206 ... phase adjuster, 10211 ... active power control, 10220 . 102B20 ... operating unit, 10215 . 102B15 ... power control, 10216 . 102B16 ... dq inverse transformer, 10217 . 102B17 ... two-phase to three-phase transformer, 10218 . 102B18 ... PWM control, 10231 ... DC voltage control, 102B11 . 10231 ... tension control, 10242 ... speed control, 10244 ... torque control

Claims (15)

 Power generation system comprising: an energy source; a power generator driven by the power source; a first breaker disposed between the power generator and an AC system; a first power converter connected to a power generator side of the first breaker; and a controller configured to control opening and closing of the first breaker and switching of the first power converter, wherein the controller controls the first breaker to be closed after starting the switching of the first power converter.  The power generation system according to claim 1, wherein the controller outputs an instruction to close the first breaker as an input using a detection value for a state that can be changed by an output signal of the first power converter.  The power generation system according to claim 2, wherein the state changeable by the output signal of the first power converter is a phase difference between a terminal voltage of the power generator and a voltage of the AC system.  A power generation system according to any one of claims 1 to 3, further comprising: a first voltage detection unit configured to detect a voltage of an AC system side of the first breaker, and a second voltage detection unit designed to detect a terminal voltage of the power generator side of the first breaker, wherein the controller uses detection signals of the first voltage detection unit and the second voltage detection unit as input signals, and a power converter controller for controlling the first power converter.  The power generation system according to claim 1, wherein the controller controls a power output from the first power converter after starting the switching of the first power converter to the power generator so as to have a polarity representing a phase difference between the voltage of the AC system and the terminal voltage of the AC power supply Energy generator reduced.  The power generation system according to claim 5, wherein the controller starts the first power converter when a number of revolutions of a rotor of the power generator exceeds a predetermined value at startup of the power generation system, and operates the first breaker after a terminal voltage of the power generator and a voltage of the AC system are synchronized with each other.  Power generation system according to one of claims 1 to 6, wherein the first power converter is connected to the power generator via a second breaker, and the controller performs such a control that, after the second interrupter has been actuated by the controller, the first interrupter is actuated.  Power generation system according to one of claims 1 to 7, wherein the energy source is a gas turbine, comprising: a compressor designed to compress air; a combustor adapted to mix and combust air and fuel compressed by the compressor; a turbine configured to achieve a rotational force due to the expansion of exhaust gases burned in the combustion chamber; and a shaft adapted to transmit the rotational force gained from the turbine to the compressor.  The power generation system according to claim 8, wherein the gas turbine is a double-shaft gas turbine including the compressor, a first gas turbine, a first shaft mechanically interconnecting the compressor and the first turbine, a second turbine capable of achieving a rotational force by receiving exhaust gas from the first turbine, and a second shaft mechanically interconnecting the second turbine and the power generator, wherein the first shaft and the second shaft are independently rotatable. Power generation system according to one of claims 1 to 9, wherein the energy source comprises a compressor, a rotary machine mechanically connected to the same shaft as the compressor, a second power converter connected to the first power converter, and a capacitor connected between the first power converter and the second power converter, and the rotary machine is connected to the second power converter.  Power generation system according to claim 10, wherein the first power converter is further connected to the first breaker and the AC system, and a switching unit is provided for switching connection states of the two connections, the connections comprising a connection between the first power converter and the power generator side of the first breaker and a connection between the first power converter and the AC system side of the first breaker.  The power generation system of claim 1, wherein when the number of revolutions of the rotor of the power generator exceeds a predetermined value, the controller breaks the connection between the first power converter on the AC system side of the first breaker and interconnects the first power converter and the power generator side of the first breaker Power generation system is started.  Power conversion system comprising: a power conversion unit connected in parallel with a power generator to an AC system via a breaker, wherein the power conversion unit comprises a power converter and a controller, and wherein the controller performs a switching operation such that a phase difference of a voltage of the AC system and a voltage of the power generator is reduced when the information that the breaker is open is input thereto as an input.  Control method for a power generation system comprising: an energy source; a power generator driven by the power source; a first breaker disposed between the power generator and an AC system; a first power converter connected to the power generator side of the first breaker; and a controller configured to open and close the first breaker and to connect the first power converter; wherein, at start-up, the first breaker for connecting the first power converter to the DC system is closed after starting to turn on the first power converter.  Control method of a power generation system comprising: an energy source; a power generator driven by the power source; a first breaker disposed between the power generator and an AC system; a first power converter connected to the power generator side of the first breaker, and a controller configured to open and close the first breaker and to connect the first power converter; wherein a phase difference between the terminal voltage of the power generator and a voltage of the AC system is reduced by controlling the switching of the first power converter.

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