JPH0634629B2 - Variable speed turbine generator system controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a turbine or pump turbine provided with a guide vane, a generator or generator-motor directly connected to the turbine or pump turbine, and The speed and output of a variable water turbine power generation system composed of a variable frequency power source for applying exciting power to a generator or a generator motor, the opening of the guide vane,
The present invention relates to an improvement in a control device that controls by the exciting power of a generator or a generator motor.

(Prior Art) The efficiency η of a turbine is the unit speed n (however, the unit speed is the speed N
Is a speed normalized by the head, and n = N / √H)
, And the guide vane opening degree a
Shown as shown. That is, as is clear from FIG. 4, in the conventional water turbine, N is operated at a constant value, so at a power plant with a large drop variation or a power plant with a large output range operated and a large guard vane opening variation range, You are forced to drive inefficiently. From this, in order to perform highly efficient operation regardless of the head and output,
A variable-speed turbine power generation system in which the speed of the turbine is changed according to the head and the output has begun to be studied (for example, "Japanese Patent Laid-Open No. 57-113971").

FIG. 5 shows an example of this type of variable speed turbine power generation system. In FIG. 5, on the secondary winding of the induction generator 2 directly connected to the water turbine 1 equipped with the guide vanes 1A,
By applying the output of the variable frequency power source 3 as the exciting power, the primary winding of the induction generator 2 generates a power synchronized with the system. On the other hand controller functions and output control unit 5 from the output request P ₀ to generate an output command ER of the variable frequency power source 3, from the above output request P ₀ and static drop HST, and outputs a speed command NR which maximizes efficiency A generator 7 and a speed controller 6 that outputs a guide vane opening command AR based on the speed command NR from the function generator 7.
The guide vane control device 4 is configured to control the guide vane opening A so that the guide vane opening command AR from the speed control unit 6 is set.

According to the above configuration, the guide vane opening A is the output demand P
₀ and the guide vane opening command AR that realizes the speed command NR determined by the head HST, and the induction generator 2
The exciting power E is controlled by the output command ER of the variable frequency power source 3 that realizes the output request P ₀ , and efficient operation can be performed.

However, in the control device of the variable speed turbine power generation system as described above, there is a disadvantage that the transient characteristics are poor. As an example, from the first operating point, which is the static drop HST, the output P ₁ , the speed N ₁ , the guide vane opening A ₁ , and the excitation power E ₁ , the static drop HST, the output P ₁ + ΔP, the speed N ₁ + ΔN,
The transient characteristics when the guide vane opening A ₁ + ΔA and the exciting power E ₁ + ΔE are changed to the second operating point will be described. For the sake of simplicity, it is assumed that the static head does not change.

That is, when the static drop HST is constant, the input / output characteristic of the function generator 7 is approximately NR = K ₁ P ₀ . Here, K ₁ is a positive constant determined by the head difference. Therefore, in order to change from the first operating point to the second operating point, the output request P ₀
When P is increased from P ₁ by ΔP, the speed command NR is also changed from N ₁ to ΔN.
The output command ER also increases by ΔE from E ₁ . As a result,
Both the guide vane opening A and the generator excitation power E start to increase. Further, the function of the change dA of the guide vane opening A and the change dPM of the turbine output PM is represented by a transfer function as shown below, as is well known.

However, T _w is a channel constant determined by the channel cross-sectional area and channel length,
Usually, it is about 0.6 to 2.0 seconds. On the other hand, since the delay of the generator output P is about several milliseconds due to the change of the generator exciting power E, the output demand P ₁ increases faster than the turbine output PM increases, and the speed N decreases. . Further, due to the delay from the change dA of the guide vane opening A to the change dPM of the turbine output PM, the characteristics of the speed control unit 6 are poor in stability and poor in responsiveness. Therefore, the settling of the speed N is slow as shown in FIG. 6, and it takes time to reach the second operating point.

(Problems to be Solved by the Invention) As described above, in the control device of the conventional variable speed turbine power generation system, stability when controlling the speed and output of the variable speed turbine power generation system in accordance with the output request is stable. There was a problem that the system could not be operated efficiently because of poor performance and responsiveness.

In view of this, the present invention provides a highly reliable variable speed turbine power generation system capable of stably and quickly controlling the speed and output of the variable speed turbine power generation system in accordance with an output request and always performing efficient operation. An object is to provide a control device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, in the present invention, a turbine or pump turbine provided with a guide vane, and a generator directly connected to the turbine or pump turbine, or The speed and output of a variable speed turbine power generation system composed of a generator motor and a variable frequency power source for applying exciting power to the generator or generator motor, the speed and output of the guide vane and the generator or generator motor. In a control device controlled by excitation power, a function generator that outputs a speed reference and a guide vane opening reference based on an output request and a static drop difference, and a detection output of a generator or a generator motor and an output request Deviation is detected, the detected output deviation is proportionally integrated, and the value obtained by adding the proportional integral value to the guide vane opening reference from the function generator is the guide vane opening command. Output controller, a guide vane controller that controls the guide vane opening so that the opening corresponds to the guide vane opening command from the output controller, and the speed reference from the function generator. An output response compensating unit that outputs a speed command based on the above, and a speed control unit that outputs an output command to the variable frequency power source so that the speed corresponds to the speed command from the output response compensating unit are configured. It is characterized by doing so.

(Operation) In the control device of the variable speed turbine power generation system described above,
The output control by the guide vane opening control and the speed control by the excitation power control from the variable frequency power source are performed at the same time, and the control for obtaining the generator output at a speed with high efficiency of the water turbine is realized according to the output request. Further, in response to a rapidly changing output request that cannot be completely tracked by the guide vane opening control, the generator output can be tracked by temporarily changing the speed reference.

(Example) Hereinafter, the present invention will be described with reference to an example shown in the drawings.

FIG. 1 shows a configuration example of a variable speed turbine power generation system to which the control device according to the present invention is applied, and the same element names as those in FIG. 5 are designated by the same reference numerals. In FIG.
Variable speed composed of a water turbine 1 having a guide vane 1A, an induction generator 2 directly connected to the water turbine 1, and a variable frequency power source 3 for applying exciting power to a secondary winding of the induction generator 2. The control device for controlling the speed and output of the turbine power generation system consists of the following. That is, based on the output request P ₀ and static drop HST, a function generator 9 which outputs a speed reference NR ₁ and the guide vane opening reference AR _1, the guide vane opening reference from the function generator 9 AR ₁ and the output control section 5 outputs the guide vane opening command AR based on the above output request P _0, the opening degree become as guide vanes open in accordance with the guide vane opening command AR from the output control section 5 The guide vane control device 4 for controlling the degree A, and the speed reference N from the function generator 9
Output response compensator 8 which outputs speed command NR based on R ₁
And a speed controller 6 for outputting an output command ER to the variable frequency power source 3 so that the speed N corresponds to the speed command NR from the output response compensator 8.

Here, the output control unit 5 includes a regulator 51 that detects a deviation between the generator output P detected by an output detector (not shown) and the output request P ₀ , a proportional-plus-integral controller 52, and the proportional-plus-integral controller. The speed controller 6 includes an adder / subtractor 53 for adding the output from 52 and the guide vane opening reference AR ₁ from the function generator 9, and the speed controller 6 detects the speed N detected by a speed detector (not shown). A proportional controller 62 and an adder / subtractor 61 for detecting a deviation from the speed command NR described above. Further, the function generator 9 _responds to the output request P ₀ by
The speed and the guide vane opening that maximize the efficiency when a static head is given are obtained from the turbine characteristics. Furthermore, the output response compensator 8 temporarily adjusts the speed command NR when the output request P ₀ changes so that the output response is improved.
Is shifted from the speed reference NR ₁ , and how to determine the characteristic will be described later.

Next, the operation of the control device of the variable speed turbine power generation system configured as described above will be described with reference to FIG. Note that FIG. 2 is a block diagram showing the operating characteristics of the entire control system in FIG.

Now, in FIG. 2, G _p (S) is a characteristic of the proportional-plus-integral controller 52 of the output control unit 5, and if the proportional gain is K _p and the integral time constant is T _p , Becomes Further, GT (S) shows the response of the turbine output PM to the guide vane opening command AR, and when the delay time constant of the guide vane control device 4 is T _v and the waterway time constant is T _w , normally T _v << Since it is T _w , Becomes Further, K ₁ is a value obtained by linearly approximating the guide vane opening-versus-speed characteristic of the function generator 9 near the operating point. T
Is an inertial time constant of the water turbine 1 and the induction generator 2, KN is a proportional gain of the proportional controller 62 of the speed control unit 6, and KN >> 1.

On the other hand, G _c (S) shows the characteristic of the output response compensator 8, and the characteristic is determined as follows. In other words, now the desired response of the output P to the output request _{P 0} and _{P = G x (S) P} 0, G c a response improvement claim of the _{G c (S) '(S} ) as a first _G c' (S) And ask And because KN >> 1, Becomes Therefore, Assuming that the output P follows the output request P ₀ as a desired response, and G _x (S) = 1, To take. By the way, since it is desirable that G _c (S) be 1 in order to perform the highly efficient operation of the water turbine 1, there is a slow change in the output demand P _{0 that} can be followed by the output control system by the guide vane opening control. On the other hand, G _c (S) = 1, and G _c (S) ≈G _c ′ for a rapid change in the output demand P _{0 that} cannot be followed by the output control system by the guide vane opening control.
G _c (S) is determined by the following equation so that (S) is obtained. However, T _p is an integration time constant of the output control system, and can be used as a standard of the response of the output control system.

Also, Since T _p >> T _w / 2 in general, the following equation may be used.

From the above, the normal output control is G _c (S) = 1,
As T (S) ≈1 From the expressions (1) and (2), the output speed is normally the output request P _0.
It can be seen that the control is performed according to.

On the other hand, for fast changes that the output control system cannot follow, As From the equations (3) and (4), the speed N can be changed for a fast speed change.
Is deviated from the target speed K ₁ P ₀ for efficiency, but the output P
Is controlled in accordance with the output request P ₀ . FIG. 3 shows a response example of the control device according to the present embodiment. It can be seen from FIG. 3 that the stability of the speed N is improved and the initial response of the output P is improved in comparison with the above-described FIG. 6 for the same change in the output request P ₀ .

As described above, in the controller of the variable speed turbine power generation system of the present embodiment configuration, the output control by the guide vane opening control and the speed control by the excitation power control from the variable frequency power source are simultaneously performed, and the output request is made. In order to realize a control that obtains a generator output at a highly efficient speed of the turbine according to the above, and for a rapidly changing output request that cannot be followed by the guide vane opening control, the speed reference is temporarily changed. This allows the generator output to be tracked. As a result, the reverse response in the initial stage of output change due to the influence of the waterway system seen in the output response of the conventional constant-speed turbine power generation system, that is, when the output is increased (or decreased), the output temporarily decreases (or increases). There is no phenomenon. Moreover, in accordance with the output demand, the operating point is highly efficient, that is, the speed and guide vane opening, which are the most efficient for generating the output at the time of the static drop, are reached quickly, and the extremely efficient power generation operation is achieved. It is possible to obtain the effect that it becomes possible to perform.

It should be noted that the present invention is not limited to the above-described embodiments, but can be carried out as follows.

In the above embodiment, the case where the present invention is applied to the variable speed turbine power generation system including the turbine and the induction generator directly connected to the turbine is described. However, the present invention is not limited to this, and the pump turbine and the generator motor directly connected to the pump turbine are also described. The present invention can be similarly applied to the variable speed turbine power generation system configured by.

In addition, the present invention can be variously modified and implemented within the scope of the invention.

[Effects of the Invention] As described above, according to the present invention, a function generator that outputs a speed reference and a guide vane opening reference based on an output request and a static head difference, and a guide vane from the function generator. An output control unit that outputs a guide vane opening command based on the opening reference and the output request, and the guide vane opening is controlled to be an opening according to the guide vane opening command from this output control unit. Guide vane control device, an output response compensator that outputs a speed command based on the speed reference from the function generator, and the variable frequency power supply so that the speed corresponds to the speed command from the output response compensator. Since it is configured to include a speed control unit that outputs an output command to the variable speed turbine, the speed and output of the variable speed turbine power generation system can be controlled stably and quickly by following the output request, and efficient operation is always possible. It is possible to provide a control device for a variable-speed turbine power generation system that is capable of rotating and has extremely high reliability.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a variable speed turbine power generation system to which a control device according to the present invention is applied, FIG. 2 is a block diagram showing characteristics of the entire control system in the embodiment, and FIG. The figure which shows the response characteristic in an example, FIG. 4 is a figure which shows the characteristic of a water turbine, FIG. 5 is a block diagram which shows an example of the conventional variable speed turbine power generation system, and FIG. 6 is a figure which shows the response characteristic in FIG. Is. 1 ... water turbine, 1A ... guide vane, 2 ... induction generator, 3 ... variable frequency power source, 4 ... guide vane control device, 5 ... output control unit, 51 ... adder, 52 ... proportional Integral controller, 53 ... Adder / subtractor, 6 ... Speed controller, 61
...... Adjuster, 62 …… Proportional controller, 7 …… Function generator,
8 ...... output response compensation unit, 9 ...... function generator, P 0 _...... output request, P ...... output, AR ...... guide vane opening command,
A: guide vane opening, HST: static head, NR: speed command, N: speed, ER: variable frequency power output command, E: excitation power of induction generator 2, AR ₁ ...... guide Vane opening reference, NR ₁ ... speed command.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Hashiguchi, No. 1, Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corp. (56) Reference JP-A-62-236393 (JP, A)

Claims (1)

[Claims] 1. A turbine or pump turbine having a guide vane, a generator or generator motor directly connected to the turbine or pump turbine, and a variable frequency power source for applying exciting power to the generator or generator motor. In a control device that controls the speed and output of a variable speed turbine power generation system that is controlled by the opening of the guide vanes and the excitation power of the generator or generator motor, a speed reference based on an output request and a static drop difference. And a function generator that outputs a guide vane opening reference, detects an output deviation between the detected output of the generator or generator motor and the output request, proportionally integrates the detected output deviation, and outputs from the function generator. Of the guide vane opening, and an output controller for outputting a value obtained by adding the proportional integral value to the guide vane opening command, and a guide vane from the output controller A guide vane control device that controls the guide vane opening so that the guide vane opening becomes an opening according to the vane opening command, and an output response compensator that outputs the speed command based on the speed reference from the function generator. Control of a variable-speed turbine generator system, characterized in that it is configured to include a speed control unit that outputs an output command to the variable frequency power source so that the speed responds to the speed command from the output response compensation unit. apparatus.