JP2014138462A - Generator control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take note of conditions unique to combined-cycle power generation plants each equipped with a gas turbine-powered generator driven by a gas turbine and a steam turbine-powered generator driven by a steam turbine operated by utilizing the exhaust heat of the gas turbine, and provide a generator control apparatus capable of reducing the required capacity of that steam turbine-powered generator.SOLUTION: In a Var command control apparatus 7, gas turbine-powered generator reactive power control means controls, in the direction of keeping reactive power Qg2 (QST) outputted by a steam turbine-powered generator 26 within a prescribed range of reactive power, reactive power Qg1 outputted by a gas turbine-powered generator 12 when the operation of steam turbine-powered generator voltage control means cannot keep the reactive power Qg2 outputted by the steam turbine-powered generator 26 within the range of reactive power.

Description

  The present invention relates to a power generation facility including a gas turbine generator driven by a gas turbine and a steam turbine generator driven by a steam turbine that operates using exhaust heat of the gas turbine. The present invention relates to a generator control device that controls the power generation equipment so that the generator capacity of a steam turbine generator can be reduced.

  In conventional reactive power control, control for keeping the generator voltage constant by AVR (automatic voltage regulator), and control for keeping the power reception rate constant by making maximum use of the reactive power capacity of the generator (for example, (See Patent Document 1).

Japanese Patent Laid-Open No. 06-014466

  Various systems such as Patent Document 1 have been introduced as reactive power control systems in power generation facilities, and steam operated by using a gas turbine generator driven by a gas turbine and exhaust heat of the gas turbine. In a so-called combined cycle power generation facility including a steam turbine generator driven by a turbine, a control method capable of reducing the required capacity of the steam turbine generator is not particularly mentioned.

  This invention pays attention to the conditions peculiar to this combined cycle power generation equipment, and it aims at obtaining the generator control apparatus which can reduce the required capacity | capacitance of the generator for steam turbines.

The generator control device according to the present invention is driven by a gas turbine generator driven by a gas turbine and a steam turbine that operates using exhaust heat of the gas turbine, which is connected to a power system via a common bus. A generator for a steam turbine that controls the power generation equipment that supplies the commanded active power and reactive power to the power system,
Gas turbine generator reactive power control means for controlling reactive power output by the gas turbine generator, and steam turbine generator when the reactive power output by the steam turbine generator exceeds a predetermined reactive power range A steam turbine generator voltage control means for controlling the voltage of the steam turbine generator within a predetermined generator voltage fluctuation allowable range so that the reactive power output by the generator falls within the reactive power range,
The gas turbine generator reactive power control means outputs when the reactive power output from the steam turbine generator does not fall within the reactive power range due to the operation of the steam turbine generator voltage control means. The reactive power output from the gas turbine generator is controlled so that the reactive power falls within the reactive power range.

  As described above, the generator control device according to the present invention includes the steam turbine generator voltage control means for keeping the reactive power output from the steam turbine generator within a predetermined reactive power range, and the steam turbine power generation. Since the reactive power control means for controlling the reactive power output by the gas turbine generator is controlled in such a direction that the reactive power output by the machine falls within the reactive power range, it is necessary for the steam turbine generator. The reactive power capacity can be specially reduced to a value corresponding to this reactive power range. Accordingly, the required capacity of the steam turbine generator is reduced, and a low-cost, space-saving power generation facility is realized.

It is a circuit block diagram which shows the electric power generation equipment containing the generator control apparatus of Embodiment 1 of this invention. It is an active power and reactive power diagram explaining a generator capacity | capacitance at the time of restrict | limiting the reactive power range which a generator outputs. It is a figure explaining the reactive power control range of a generator in this invention. It is a flowchart explaining operation | movement of the generator control apparatus of Embodiment 1 of this invention. It is a circuit block diagram which shows the power generation equipment containing the generator control apparatus of Embodiment 2 of this invention. It is a flowchart explaining operation | movement of the generator control apparatus of Embodiment 2 of this invention. It is a circuit block diagram which shows the power generation equipment containing the generator control apparatus of Embodiment 3 of this invention. It is a flowchart explaining operation | movement of the generator control apparatus of Embodiment 3 of this invention. It is a circuit block diagram which shows the power generation equipment containing the generator control apparatus of Embodiment 4 of this invention. It is a flowchart explaining operation | movement of the generator control apparatus of Embodiment 4 of this invention. It is a circuit block diagram which shows the power generation equipment containing the generator control apparatus of Embodiment 5 of this invention. It is a flowchart explaining operation | movement of the generator control apparatus of Embodiment 5 of this invention.

Embodiment 1 FIG.
FIG. 1 is a circuit configuration diagram showing a power generation facility including a generator control apparatus according to Embodiment 1 of the present invention. Before entering the description, first, an overview of the present invention and a background leading to the creation of the present invention will be described. explain.
The left figure (a) of FIG. 2 shows a conventional generator output possible curve. The horizontal axis represents the generator active power Pg (W), and the vertical axis represents the generator reactive power Qg (Var).
Typically, the generator adjusts the reactive power Qg (Var) of the generator so that the generator voltage fluctuates within ± 5% within the output possible curve, and keeps the bus voltage of the generator equipment constant.

On the other hand, the right figure (b) of FIG. 2 has shown the case where the adjustment range of reactive power is restrict | limited.
Since the generator capacity (MVA) can be expressed by MVA = √ (Pg ² + Qg ² ), the generator capacity MVA can be reduced by reducing the adjustment range of the reactive power Qg.
Conventionally, even if the system voltage of the power system to which the generator is connected fluctuates, the reactive power Qg (Var) of the generator is controlled to keep the bus voltage of the power generation equipment constant. Thus, if the fluctuation range of the reactive power Qg (VAR) of the generator can be suppressed even if the system voltage fluctuates, the generator capacity MVA can be reduced accordingly.

Here, the relationship between the bus voltage of the power generation facility and the system voltage will be described.
First, the active power of the generator is expressed by equation (1), the reactive power is expressed by equation (2), the active current is expressed by equation (3), and the reactive current is expressed by equation (4).

Effective power: Pg = √3IV cos θ (1)
Reactive power: Qg = √3IV sin θ (2)
Effective current: I cos θ = Pg / (√3 V) (3)
Reactive current: Isin θ = Qg / (√3 V) (4)

Where V is a voltage effective value, I is a current effective value, and θ is a phase angle.
Further, when the system voltage is Vs, the reactance of the system is Ls, the resistance is Rs, and the current flowing from the system side is Is, the bus voltage Vb is expressed by equation (5).

  Vb = Vs−LsIs · sin θ−RsIs · cos θ (5)

  Further, the current Is can be expressed by equation (6) where MVA is the output of the generator, Vg is the voltage of the generator, and VL / VH is the transformation ratio of the transformer.

  Is = MVA / (√3Vg) · VL / VH (6)

Here, in order to reduce the voltage fluctuation range of the bus voltage Vb of the power generation equipment, since Is · cos θ (active current) is determined and fixed by the turbine output (active power) in the equation (5), Is · sin θ This is done by changing the (reactive current).
That is, in the equation (5), when it is desired to increase or decrease the bus voltage Vb, the generator operation is changed to delay or advance as in 1) and 2) below, that is, Vb is increased or decreased by increasing or decreasing the reactive power. Can be controlled.

1) Increase the bus voltage Vb of the power generation equipment: -LsIs · sinθ large (delayed operation direction: reactive power increase)
2) Decrease the bus voltage Vb of the power generation equipment: -LsIs · sin θ small (advance driving direction: reactive power reduction)

  As described above, in order to reduce the fluctuation range of the bus voltage Vb of the power generation facility, it is necessary to increase or decrease the reactive power from the generator. The capacity of the steam turbine generator can be reduced by controlling the reactive power Q (VAR) of the turbine generator to make the fluctuation range of the reactive power Q (Var) of the steam turbine generator below a certain range. It is intended.

  In the combined cycle power generation facility, the steam turbine does not operate alone because steam is obtained using exhaust heat from the gas turbine. That is, when the steam turbine is operating, the gas turbine is always operating. Therefore, if the fluctuation range of the bus voltage can be substantially suppressed by the gas turbine generator, the reactive power adjustment range imposed on the steam turbine generator may be small.

  In this way, when the gas turbine generator and the steam turbine generator are operated together in the combined cycle, the present invention creatively pays attention to the so-called master-slave relationship in the reactive power adjustment capability. It was created and the reactive power adjustment capability inherent to the gas turbine generator was effectively utilized to reduce the amount of reactive power adjustment imposed on the steam turbine generator. It can be said that it contributes to miniaturization.

Hereinafter, electrical equipment according to the generator control device of Embodiment 1 of the present invention will be described in detail with reference to FIG.
In FIG. 1, a gas turbine generator 12 is connected to the power system 1 through a bus 2, a substation circuit breaker 4, a gas turbine main transformer 5, and a generator circuit breaker 6. The gas turbine generator 12 controls the generator voltage by controlling the field current flowing in the field winding 13 by the AVR 11. Further, the voltage detection VT 8 and the excitation transformer 7 are connected to the generator circuit. The protection relay 9 is installed to protect the gas turbine generator 12.

The bus voltage is input to the Var command control device 17 as the gas turbine generator reactive power control means described in the claims of the present application after the output of the bus voltage detection VT 15 is converted by the voltage converter 16. The Var command control device 17 also receives the outputs of the main circuit current detection CT 10 and the voltage detection VT 8.
Further, the Var command control device 17 also functions as a steam turbine generator voltage control means described in the claims by inputting a necessary signal of a steam turbine generator described later.

Similarly, a steam turbine generator 26 is connected to the power system 1 via the bus 3, the substation circuit breaker 18, the steam turbine main transformer 19, and the generator circuit breaker 20. The steam turbine generator 26 controls the generator voltage by controlling the field current flowing in the field winding 27 by the AVR 25. Further, a voltage detection VT 22 and an excitation transformer 21 are connected to the generator circuit. The protection relay 23 is installed to protect the steam turbine generator 26.
The current flowing through the steam turbine generator 26 is detected by the main circuit current detection CT 24 and is input to the Var command control device 17 together with the signal from the excitation transformer 21.

This configuration is applied to a combined cycle plant including a gas turbine and a steam turbine driven by steam generated by using exhaust gas from the gas turbine.
In addition, in FIG. 1, although the generator circuit is described as the case where the generators 12 and 26 are thyristor excitation methods, the same effect can be obtained even when a brushless excitation method generator is used instead. The same applies to each embodiment described later.

  Next, the operation, in particular, the control operation for keeping the reactive power Qg2 of the steam turbine generator 26 (however, in the following flowchart, the detected reactive power is referred to as QST) within a predetermined reactive power range. 4 will be described.

Since the generator voltage generally allows a variation of ± 5%, when the system voltage fluctuates, the reactive power of the steam turbine generator 26 is changed, and the generator voltage is changed to generate power. Keep the equipment bus voltage constant.
As a result, when the system voltage rises, in order to suppress the voltage rise, the operating point of the generator is shifted to the advanced operation side, and the reactive power of the generator is reduced. Further, when the system voltage decreases, the voltage is increased, so that the operating point of the generator moves to the delayed operation side, and the reactive power of the generator increases.

In FIG. 4, first, in step SA1, as described above, the reactive power QST of the steam turbine generator 26 that fluctuates with the system-side voltage fluctuation is detected, and the reactive power QST is set as a predetermined reactive power range. It is determined whether or not it is within a preset range between the upper limit QH and the lower limit QL.
If it is within the reactive power range (Y in step SA1), the special control mentioned here is unnecessary, and the process returns to the STG operation which is a normal control system.

When it is out of the reactive power range (N in step SA1), the process proceeds to step SA2, and it is determined whether or not QST is larger than the upper limit QH.
When QST is larger than the upper limit QH (Y in step SA2), the process proceeds to step SA3, and a command to lower the voltage of the steam turbine generator 26 by a predetermined width (for example, 0.01 pu = 1%) is output.

Until this voltage reaches a lower limit value to be described later (N in step SA4), the process returns to step SA1. If QST falls within the reactive power range due to the voltage reduction of the predetermined width (Y in step SA1), it returns during normal STG operation, and if it still does not fall within this reactive power range (N in step SA1). ) Again, the voltage reduction is commanded in step SA3.
The foregoing corresponds to the operation of the Var command control device 17 mainly for the steam turbine generator voltage control means.

  When this voltage lowering instruction continues and the voltage of the steam turbine generator 26 reaches the allowable lower limit of 0.95 pu = 95% (Y in step SA4), that is, the operation of the steam turbine generator voltage control means If QST does not fall within the reactive power range, the process proceeds to step SA7, and a Var increase command is issued to increase the reactive power Qg1 output by the gas turbine generator 12 in a direction in which QST falls within the reactive power range. Output.

  On the other hand, if it is determined as N in both steps SA1 and SA2, the process proceeds to step SC2 because QST is smaller than the lower limit QL of the predetermined reactive power range, and the voltage of the steam turbine generator 26 is set to a predetermined width ( For example, a command to increase by 0.01 pu = 1%) is output. Thereafter, as in the case of lowering the voltage (steps SA3 and SA4), this voltage increase command continues, and when the voltage of the steam turbine generator 26 reaches the allowable upper limit value of 1.05 pu = 105% (in step SC3). Y), that is, when QST does not fall within the reactive power range due to the operation of the steam turbine generator voltage control means, the process proceeds to step SC6, in the direction in which QST falls within the reactive power range, and accordingly, the power generation for gas turbine. A Var lowering command for reducing the reactive power Qg1 output from the machine 12 is output.

  As described above, in the Var command control device 17 of the generator control device according to the first embodiment of the present invention, the steam turbine generator voltage control means has the reactive power QST (Qg2) output from the steam turbine generator 26. ) Exceeds the predetermined reactive power range (upper limit QH, lower limit QL), the voltage of the steam turbine generator 26 is controlled within a predetermined generator voltage fluctuation allowable range so that the QST falls within the range, and the gas turbine When the steam turbine generator voltage control means is operated so that the QST does not fall within the reactive power range, the generator reactive power control means for gas is output by the gas turbine generator 12 in such a direction that the QST falls within that range. Since the electric power Qg1 is controlled, the necessary reactive power capacity of the steam turbine generator 26 can be reduced to a value corresponding to this reactive power range. Low cost by reducing the required capacity of the gas turbine generator 26, power generation equipment space-saving can be realized.

Embodiment 2. FIG.
FIG. 5 is a circuit configuration diagram showing a power generation facility including a generator control device according to Embodiment 2 of the present invention.
The Var command control device 17A of FIG. 5 includes first tap switching control means described in the claims of the present application in addition to the steam turbine generator voltage control means described in the first embodiment.
Correspondingly, in FIG. 5, the steam turbine main transformer 19 is a first load tap change transformer 19A equipped with an OLTC (On load tap changer), and this tap change control. In this configuration, a signal necessary for the operation is instructed from the Var command control device 17A.

Next, a control operation for keeping the reactive power QST of the steam turbine generator 26 within a predetermined reactive power range will be described with reference to FIG.
The operations in steps SA1 to SA4 are the same as those in FIG.

  When Y in step SA4, that is, even when the voltage of the steam turbine generator 26 reaches the allowable lower limit of 0.95 pu, the operation of the steam turbine generator voltage control means causes the QST to fall within the reactive power range. If not, the process proceeds to step SA5, and a command to lower the tap position of the first load tap change transformer 19A by a predetermined width is output.

  Until this tap position reaches a lower limit position described later (N in step SA6), the process returns to step SA1. If QST falls within the reactive power range due to the tap position lowering by the predetermined width (Y in step SA1), it returns during normal STG operation, and if it still does not fall within this reactive power range (N in step SA1). ) Again, the tap position lowering is instructed in step SA5.

  The above is equivalent to the operation of the steam turbine generator voltage control means of the Var command control device 17A and the subsequent first tap switching control means.

  When this tap position lowering instruction continues and the tap position of the first load tap switching transformer 19A reaches the allowable lower limit position (Y in step SA6), that is, by the operation of the first tap switching control means. If QST does not fall within the reactive power range, the process proceeds to step SA7, and a Var increase command is output to increase the reactive power Qg1 output by the gas turbine generator 12 in a direction in which QST falls within the reactive power range. To do.

On the other hand, the operations up to steps SA1, SA2, SC2, and SC3 when QST is smaller than the lower limit QL of the predetermined reactive power range are the same as those in FIG.
When the result in step SC3 is Y, that is, even when the voltage of the steam turbine generator 26 reaches the allowable upper limit of 1.05 pu, the operation of the steam turbine generator voltage control means causes the QST to fall within the reactive power range. If not, the process proceeds to step SC4, and a command to increase the tap position of the first load tap change transformer 19A by a predetermined width is output.

  Thereafter, as in the case of lowering the tap position (steps SA5 and SA6), this tap position raising command continues, and when the tap position of the first load tap change transformer 19A reaches a predetermined upper limit (step). Y in SC5), that is, when QST does not fall within the reactive power range due to the operation of the first tap switching control means, the process proceeds to step SC6, in the direction in which QST falls within the reactive power range, and accordingly, power generation for the gas turbine. A Var lowering command for reducing the reactive power Qg1 output from the machine 12 is output.

  As described above, Var command control device 17A of the generator control device according to Embodiment 2 of the present invention has reactive power QST (Qg2) output from steam turbine generator 26 within a predetermined reactive power range (upper limit QH, When the lower limit QL) is exceeded, the generator voltage control means for the steam turbine, and then the first tap switching control means, controls each means within the predetermined control allowable range so that the QST falls within the range, and the gas turbine When the QST does not fall within the reactive power range due to the operation of the first tap switching control means, the generator reactive power control means for reactive power Qg1 is output from the gas turbine generator 12 in a direction in which the QST falls within the range. Therefore, the necessary reactive power capacity of the steam turbine generator 26 can be reduced to a value corresponding to this reactive power range. Low cost by reducing the required capacity of the generator 26, power generation equipment space-saving can be realized.

Embodiment 3 FIG.
FIG. 7 is a circuit configuration diagram showing a power generation facility including a generator control device according to Embodiment 3 of the present invention.
The Var command control device 17B of FIG. 7 includes second tap switching control means described in the claims of the present application in addition to the first tap switching control means described in the second embodiment.
Correspondingly, in FIG. 7, the gas turbine main transformer 5 is also a second load tap change transformer 5A equipped with OLTC, similar to the steam turbine main transformer, and is necessary for this tap change control. The signal is instructed from the Var command control device 17B.

Next, a control operation for keeping the reactive power QST of the steam turbine generator 26 within a predetermined reactive power range will be described with reference to FIG.
The operations in steps SA1 to SA6 are the same as those in FIG.

  When Y is determined in step SA6, that is, even when the tap position of the first load tap switching transformer 19A reaches a predetermined lower limit position, QST is within the reactive power range by the operation of the first tap switching control means. If not, the process proceeds to Step SA7, and a Var increase command is output to increase the voltage of the gas turbine generator 12 by a predetermined width (for example, 0.01 pu = 1%).

Until this voltage reaches an upper limit value described later (N in step SA8), the process returns to step SA1. If QST falls within the reactive power range due to the voltage increase of the predetermined width (Y in step SA1), the operation returns to normal STG operation, and if it still does not fall within this reactive power range (N in step SA1). ) Again, in step SA7, a command to increase Var is commanded.
The above corresponds to the operation of the gas turbine generator reactive power control means of the Var command control device 17B.

  When this Var increase command continues and the voltage of the gas turbine generator 12 reaches the allowable upper limit of 1.05 pu = 105% (Y in step SA8), that is, the gas turbine generator reactive power control means If QST does not fall within the reactive power range in operation, the process proceeds to step SA9 to output a command to increase the tap position of the second load tap change transformer 5A in the direction in which QST falls within the reactive power range. .

On the other hand, the operations in steps SA1, SA2, and SC2 to SC5 when QST is smaller than the lower limit QL of the predetermined reactive power range are the same as those in FIG.
When Y is determined in step SC5, that is, even when the tap position of the first load tap switching transformer 19A reaches a predetermined upper limit position, the QST is in the reactive power range by the operation of the first tap switching control means. If not, the process proceeds to step SC6 to output a Var lowering command for lowering the voltage of the gas turbine generator 12 by a predetermined width (for example, 0.01 pu = 1%).

  Hereinafter, as in the case of Var increase (steps SA7 and SA8), this Var lowering instruction continues, and when the voltage of the gas turbine generator 12 reaches an allowable lower limit value 0.95pu (Y in step SC7), That is, if the QST does not fall within the reactive power range due to the operation of the gas turbine generator reactive power control means, the process proceeds to step SC8, in the direction in which the QST falls within the reactive power range, and accordingly the second load tap switching. A command to lower the tap position of the transformer 5A is output.

  As described above, in the Var command control device 17B of the generator control device according to Embodiment 3 of the present invention, the reactive power QST (Qg2) output from the steam turbine generator 26 has a predetermined reactive power range (upper limit QH, When the lower limit QL) is exceeded, the steam turbine generator voltage control means, the first tap switching control means, and further the gas turbine generator reactive power control means set the respective means so that the QST falls within the range. When the control is performed within the allowable control range and the QST does not fall within the reactive power range due to the operation of the gas turbine generator reactive power control means, the second tap switching control means moves the second tap in the direction in which the QST falls within the range. Since the tap position of the on-load tap switching transformer 5A is controlled, the required reactive power capacity of the steam turbine generator 26 is reduced to a value corresponding to this reactive power range. Can, with this, low cost by reducing the required capacity of the steam turbine generator 26, power generation equipment space is realized.

Embodiment 4 FIG.
FIG. 9 is a circuit configuration diagram showing a power generation facility including the generator control device according to Embodiment 4 of the present invention.
The Var command control device 17C of FIG. 9 is the case where the reactive power QST of the steam turbine generator 26 is smaller than the lower limit QL of the predetermined reactive power range, and the second tap switching control described in the third embodiment. When the QST does not fall within the reactive power range even by the operation of the means, the steam turbine 28 is controlled to reduce the effective power output from the steam turbine generator 26.

  FIG. 10 is a flowchart showing the control operation of the Var command control device 17C in the fourth embodiment. In FIG. 10, the operations of steps SA1 to SA9 when QST is larger than the upper limit QH of the reactive power range, and the operations of steps SC2 to SC7 when QST is smaller than the lower limit QL are the same as those in FIG. Omitted.

  When the command for lowering Var in step SC6 continues and the voltage of the gas turbine generator 12 reaches the allowable lower limit value 0.95 pu (Y in step SC7), that is, the operation of the gas turbine generator reactive power control means If QST does not reach the lower limit QL, the process proceeds to step SC8, and a command to lower the tap position of the second load tap change transformer 5A by a predetermined width is output.

  Then, when this tap position lowering instruction continues and the tap position of the second load tap change transformer 5A reaches a predetermined lower limit position (Y in step SC9), that is, the second tap change control means When QST does not reach the lower limit QL in operation, the process proceeds to step SC10, where the governor of the steam turbine 28 is controlled to reduce the effective power output from the steam turbine generator 26.

  As described above, when the active power is reduced, the bus voltage decreases, and the steam turbine generator 26 operates to increase the reactive power to compensate for the voltage drop. As a result, the QST is reduced to the lower limit QL. Can be close to.

  On the contrary, when QST> QH (the flow on the left side in FIG. 10), if the active power is reduced, the reactive power is further increased, and thus the countermeasure for reducing the active power is not adopted.

  As described above, in the Var command control device 17C of the generator control device according to the fourth embodiment of the present invention, the reactive power QST (Qg2) output from the steam turbine generator 26 is set to the lower limit QL of the predetermined reactive power range. In this case, the steam turbine generator voltage control means, the first tap switching control means, the gas turbine generator reactive power control means, and the second tap switching control means are arranged so that the QST falls within the range. When the QST does not reach the lower limit QL even if each means is controlled within the predetermined allowable control range, the effective power output from the steam turbine generator 26 is reduced. The necessary reactive power capacity can be reduced to a value corresponding to this reactive power range, and accordingly, the required capacity of the steam turbine generator 26 is reduced, resulting in low cost and space saving. Electrical equipment can be realized.

Embodiment 5 FIG.
FIG. 11 is a circuit configuration diagram showing a power generation facility including a generator control apparatus according to Embodiment 5 of the present invention, and FIG. 12 is a flowchart for explaining the operation thereof.
In the fifth embodiment, the reactive power QST (Qg2) output from the steam turbine generator 26 is set to a predetermined value by increasing the number of units of the gas turbine generator 12 (two units are provided here). This increases the ability to fall within the reactive power range, thereby further reducing the capacity of the steam turbine generator 26.

As shown in FIG. 11, two gas turbine generators 12 are provided for one steam turbine generator 26.
Since the configuration and operation are basically the same as in the case of the fourth embodiment, each description is omitted, but there are two gas turbine generators 12 in the flowchart of FIG. 12 showing the operation. Accordingly, for the Var control of the gas turbine generator 12 and the control of the second tap switching control means, Steps SA7 to SA9 and Steps SB1 to SB3, Steps SC6 to SC9 and Steps SD1 to SD4, Each operates in parallel flow.

Embodiment 6 FIG.
In each of the previous embodiments, the installation process of each device is not particularly mentioned, but the gas turbine generator 12 is replaced by an existing generator depending on the plant, and the steam turbine generator 26 is A new generator can be considered. In this case, the control device of the existing generator is substituted for the Var command control device 17, and functions such as a generator reactive power control means for the gas turbine are provided to reduce the cost of the control components, and the newly installed steam The capacity of the turbine generator can be reduced.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 Power system, 2 and 3 buses, 5 Main transformer for gas turbine,
5A Second load tap change transformer, 12 Gas turbine generator,
17, 17A, 17B, 17C Var command control device,
19 Steam turbine main transformer, 19A First load tap change transformer,
26 Generator for steam turbine.

Claims (6)

A gas turbine generator driven by a gas turbine and a steam turbine generator driven by a steam turbine that operates using exhaust heat of the gas turbine, connected to a power system via a common bus. Comprising, and controlling the power generation equipment that supplies the commanded active power and reactive power to the power system,
Gas turbine generator reactive power control means for controlling reactive power output by the gas turbine generator, and when the reactive power output by the steam turbine generator exceeds a predetermined reactive power range, the steam turbine A steam turbine generator voltage control means for controlling the voltage of the steam turbine generator within a predetermined generator voltage fluctuation allowable range so that the reactive power output by the generator for power generation falls within the reactive power range;
When the reactive power output by the steam turbine generator does not fall within the reactive power range in the operation of the steam turbine generator voltage control means, the gas turbine generator reactive power control means A generator control device that controls reactive power output by the gas turbine generator in a direction in which reactive power output by a generator is within the reactive power range. A first load tap switching transformer connected between the bus and the steam turbine generator, and a first tap switching control means for controlling a tap position of the first load tap switching transformer,
When the reactive power output from the steam turbine generator does not fall within the reactive power range by the operation of the steam turbine generator voltage control means, the first tap switching control means Control the tap position of the first load tap switching transformer within a predetermined tap position allowable range so that the reactive power to be output falls within the reactive power range,
The gas turbine generator reactive power control means is configured such that when the reactive power output by the steam turbine generator does not fall within the reactive power range by the operation of the first tap switching control means, the steam turbine generator 2. The generator control device according to claim 1, wherein the reactive power output by the gas turbine generator is controlled in a direction in which the reactive power output by the gas turbine falls within the reactive power range. A second load tap change transformer connected between the bus and the gas turbine generator, and a second tap change control means for controlling the tap position of the second load tap change transformer,
The gas turbine generator reactive power control means is configured such that when the reactive power output by the steam turbine generator does not fall within the reactive power range by the operation of the first tap switching control means, the steam turbine generator Control the voltage of the gas turbine generator within a predetermined generator voltage fluctuation allowable range so that the reactive power output by the generator falls within the reactive power range,
When the reactive power output from the steam turbine generator by the operation of the gas turbine generator reactive power control means does not fall within the reactive power range, the second tap switching control means is configured to generate the steam turbine generator. The generator control device according to claim 2, wherein the tap position of the second load tap change transformer is controlled in a direction in which the reactive power output by the power generator falls within the reactive power range. When the reactive power output by the steam turbine generator exceeds the lower limit of the reactive power range by the operation of the second tap switching control means, the reactive power output by the steam turbine generator is within the reactive power range. 4. The generator control device according to claim 3, wherein the effective power output from the steam turbine generator is reduced so as to be within a lower limit. 2. The capacity of the reactive power output by the steam turbine generator to be within the reactive power range is increased by increasing the number of units of the gas turbine generator. Item 5. The generator control device according to any one of items 4 to 6. The gas turbine generator is a replacement of an existing generator, and when the steam turbine generator is a newly installed generator, the gas turbine generator reactive power control means is provided for the existing generator. The generator control device according to any one of claims 1 to 5, wherein a control device is used instead.

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