JPS63114599A - Variable speed power generator - Google Patents

Abstract

PURPOSE:To improve the degree of stability of an electric power system, by a method wherein the phase angle of an exciting voltage, given to the secondary exciting coil of a synchronizer, or the absolute value of the exciting voltage is controlled in accordance with the power fluctuation of the power system. CONSTITUTION:A command value operating unit 15 reads a static head H and an effective power command value P0 and operates the opening degree commanding value V of a governor valve 12 and a speed commanding value N0. A phase angle operating unit 16 reads the effective power P, the effective power command value P0, the speed commanding value N0, which are operated by an effective power operating unit 21, and a detected speed N and operates a phase angle DELTA based on a phase angle, obtained by abovedescribed values, and the change rate P of the effective power, operated by an effective power change rate operating unit 26. An exciting amount setting unit 17 sets the exciting amount V1-V3 of the secondary coils 6a-6c based on the detected speed N, the phase angle delta and the output of a voltage regulating unit 18.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a variable pumped storage power generation device that can be operated at any rotation speed, and in particular to a power system using a synchronous machine with a three-phase secondary winding. The present invention relates to a variable pumped storage power generation device suitable for improving the stability of.

[Conventional technology]

A generally known pumped storage power plant is a type of regulating pond type or water storage type power plant.When the load on the power system is light and there is surplus power in other power plants, it is used to pump pumps to high places. Pump water into a pond and store it, and use it when necessary, such as when the river is dry or when the load is heavy.
This is the method of taking a train.

In such pumped storage power plants, it is not possible to level the load when pumping water, and the efficiency of the power plant changes due to changes in the generated power required from the grid during power generation and pumping operations, and the head during pumping. It has the disadvantage of being

Therefore, recently there has been a demand for J! ff1ffiResearch is progressing on how to operate at maximum efficiency regardless of power or lift. In order to achieve this purpose, instead of a pumped storage generator configured with a conventional synchronous machine, a method of controlling secondary excitation is adopted to create a pumped storage generator with a synchronous machine consisting of a three-phase winding on the secondary side. I have a way of thinking.

Since the synchronous machine that employs this secondary excitation control method is capable of variable speed operation, it is possible to operate the power generation device at maximum efficiency regardless of the generated power or pumped water.

The idea of variable-speed operation of large-capacity synchronous motors, even for synchronous machines, is known in ``Variable-speed operation characteristics of large-capacity synchronous motors'' (Proceedings of the 1981 IEEJ Interconference). .

On the other hand, in recent years, electric power systems have become more complex and large-scale, making it difficult to provide a stable supply of high-quality electricity.Variable-speed pumped storage power generation equipment can be used effectively to improve stability. It is necessary to do so.

[Problem that the invention seeks to solve]

In the above-mentioned variable speed operation system using a synchronous machine, no consideration has been given to improving system stability, and the variable speed operation system using a synchronous machine with a three-phase secondary winding is used. The device is also currently in the research stage, and there is no device that takes system stability into consideration.

An object of the present invention is to provide a variable speed power generation device that can improve system stability in a variable speed power generation device using a synchronous machine having a three-phase secondary winding.

[Means for solving problems]

In order to solve the above problems and achieve the purpose of the present invention,
The present invention provides a variable speed power generation device using a synchronous machine (100) having a three-phase secondary winding, which includes a power fluctuation detection section (19, 20, 24, 25) that detects the amount of power fluctuation in a power system. , the phase angle or absolute value of the excitation voltage (vt+V21 Vl) to be applied to the secondary excitation windings (6a, 6b, 6c) of the synchronous machine (100) according to the detected power fluctuation amount (ΔP, ΔQ). The present invention is characterized in that it includes a control section (50A) for controlling.

According to a more specific aspect, the power fluctuation detection section is configured to detect a power fluctuation value of a power system to which the variable continuous power generation device is connected (24, 25).

Furthermore, the power fluctuation detection section also includes an active power component (P
) and reactive power component (Q), and the control section controls (16) the phase angle (Δδ) of the secondary excitation voltage based on the detected active power value (ΔP), and the detected reactive power value (ΔQ).
) to control the absolute value of the secondary excitation voltage (Vl, V21 Vl) (18).

[Effect]

According to the configuration of the present invention, the power fluctuation detection section detects the amount of power fluctuation at a point to be controlled in the power system, and depending on the detected value, the phase angle of the excitation voltage applied to the secondary excitation winding of the synchronous machine or Since the absolute value is controlled, excess power generated due to power fluctuations can be absorbed by the synchronous machine, and the deficit can be compensated for by increasing the output of the synchronous machine. Therefore, it is possible to suppress power fluctuations occurring in the grid and improve the stability of the grid.

According to a more specific aspect, since the power fluctuation detection unit detects the fluctuation value of the power system to which the variable continuous power generation device is connected, it is possible to suppress power fluctuations at fluctuation points in the power system.

Further, according to another aspect, since the power fluctuation detection unit detects the fluctuation value of the output power of the variable power generation device itself, it is possible to suppress fluctuations caused by the variable continuous power generation device itself. Can be done.

Furthermore, according to another aspect, the power fluctuation detection unit detects the power fluctuation value of the power system to which the variable linked power generation device is connected and the fluctuation value of the output power of the variable linked power generation device itself. It is possible to suppress not only power fluctuations in the power supply system but also fluctuations caused by the variable linked power generation device itself.

Furthermore, according to another aspect, the power fluctuation detection unit detects an active power component and a reactive power component, and the control unit controls the phase angle of the secondary excitation voltage based on the active power detection value, and controls the reactive power component. Since the absolute value of the secondary excitation voltage is controlled based on the detected value, it is possible to quickly and accurately compensate for power fluctuations.
It can perform the same function as vC (static voltage compensator).

〔Example〕

Next, embodiments according to the present invention will be described based on the drawings.

First, an overview of a variable speed power generator using a synchronous machine (hereinafter referred to as synchronous machine) having a three-phase secondary winding will be explained.

FIG. 2 shows the overall configuration when a synchronous machine is used. The synchronous machine 100 includes a stator 1 having a three-phase secondary winding W5at 5b15c, and a three-phase secondary winding 6a s 6 b.

It consists of a rotor 2 with 6c.

If the rated frequency is f and the slip is S, the speed of one rotor 2 is f(1-s), and the secondary winding of the rotor 2 is slip S.
By excitation at a frequency of , the rotating magnetic field of the rotor 2 rotates at zero (synchronous speed), and becomes the same as the speed of the rotating magnetic field of the stator 1.

The control unit 50 controls the excitation of the secondary windings 6 a + 6 b t 6 c. The control unit 50 controls excitation voltages vz, V2 . Generates V8,
It is added to the secondary windings 6a, 6b, and 6c.

Here, E is the voltage value determined by the slip S and the operating status and system status of the variable speed synchronous machine 100, and δ0 is the voltage value determined by the synchronous machine 100.
Phase angle determined by 00 operating condition.

Δδ is a phase angle controlled by an external power command and control signal.

With the above configuration, even if the operation is performed at any rotation speed, the armature windings (windings 5a, 5 of stator 1) are always connected.
b, 5Q), it is possible to generate a voltage at the system frequency. That is, in the example of FIG. 2, the rotating magnetic field of the rotor 2 is f (1g) +f-s=f (2
), and a rotating magnetic field of the rated frequency f can be obtained regardless of the slippage S.

The above synchronous machine 100 is used as a generator for a pumped storage power plant.

An object of the present invention is to use the synchronous machine 100 to suppress power fluctuations caused by power fluctuations in the power system and improve stability.

Next, FIG. 1 shows an embodiment of a variable speed power generator according to the present invention.

In Figure 1, normal synchronous generators Of and Gx are connected via power transmission lines iL'z and Lz, and the output Tr! Indicates when you are driving. Generally, as the power transmission lines Lx and Lx become longer distances, the system becomes unstable, and there is a concern that even the slightest disturbance will cause unrest.

In order to suppress this, the gist of the present invention is to install a variable speed power generation device via the power transmission line L3 and to control this device.

The rotating shaft of the rotor 2 of the synchronous machine 100 is directly connected to a water wheel 13, and the rotor 2 is rotated by the water wheel 13. Water wheel 13
The guide valve 12 is controlled by a valve opening setting device 14,
The secondary windings 6a, 6b, 6c of the synchronous machine 100 are provided with phase shifters 23a, 23b.

23c supplies power with a predetermined phase difference angle.

The above two controls (control of water turbine 13 and control of synchronous machine 100
The restriction 'a) is based on the following method. That is, in the control device 50A, the command value calculation unit 15 calculates the static head (head)
H1 output command value (active power command value) Po is taken in, and the opening command value V of the governor valve 12 is calculated in consideration of efficiency and the speed command value N is calculated.

Calculate. The valve opening setting device 14 receives the opening command value V and adjusts the opening of the guide valve 12 after a predetermined time delay.

The phase angle calculation section 16 takes in the active power P calculated by the active power calculation section 21, the active power command value PO, the speed command value No., and the detected speed N, and calculates the phase angle and the amount of change in active power calculated from these. The sum of phase angles Δδ calculated based on the amount of change in active power ΔP calculated by the calculation unit 26 gives 2
The phase angle δ0 of the next winding excitation voltage V 1 *V Z + V B is controlled. The calculated active power value P is calculated by the current transformer 19.
Based on the current and Wi pressure obtained by the voltage transformer 20,
It is calculated by the active power detection section 21. The amount of change in active power ΔP is determined by the current transformer 24. It is calculated by the active power change calculation unit 26 based on the current and W1 voltage obtained by the voltage transformer 25, and is obtained by, for example, a circuit as shown in FIG. The detected speed N is detected by the speed detector 11.

The excitation amount setting section 17 sets the secondary windings 6a, 6b based on the detected speed N, the phase angle Δδ, and the output of the voltage adjustment section 18.
, 6c are set. By this excitation amount setting section 17, the 1-phase shifters 23a, 23b, 23c
The phase of this phase-shifted excitation amount v1y V2.
g Va controls the excitation of the secondary windings 6a, 6b, and 6c.

The output of the voltage transformer 20 is corrected by the correction section 28 based on the output of the reactive power change amount calculation section 27, and is input to the power adjustment section 18. The amount of change in reactive power ΔQ is determined by the current transformer 24. It is determined from the current and voltage of the voltage transformer 25, and is determined by the same process as the active power change amount calculation unit 21 shown in FIG.

FIG. 3 shows details of the active power change amount calculation section 26, in which the active power calculation section 26a calculates the m-pressure transformer 25. Voltage of current transformer 24.

Active power is determined from the current, and the output of this output via the first-order lag circuit 26b is subtracted from the output of the active power calculation section 26a by a subtraction section 26c. By doing so, the effective power change amount ΔP can be obtained. In Figure 3, T1 is a time constant.

S is a Laplace operator.

The phase angle calculation unit 16 in FIG. 1 performs the following calculation, for example.

δ=f kx (P Po)dt+ f kg (N
-No) dt '+ ni (P-Po) + Kz (N-
No) KsΔP...(3) Here, kt, ki, Kz* Kz and Kg are constants.

Next, in the configuration shown in FIG. 1, control when fluctuation occurs in the power flowing through the power transmission lines Ll and L2 will be described.

When fluctuations occur in the active power in the systems Lx and Lx, the active power change amount calculation unit 26 calculates the active power change amount ΔP. Therefore, only the fluctuation amount is extracted by the value ΔP (3) The secondary excitation voltage of the synchronous machine 100 is "/l, V
Since the phases of Z and Va are controlled, a control amount of -ΔP is given to a variation amount of +ΔP, and vice versa. Therefore, as shown in FIG. 4, power fluctuations are suppressed.

A reactive power change amount ΔQ is also determined for fluctuations in the reactive power Q, and this value ΔQ determines the secondary excitation voltage v1. V2. V
Since the absolute value of B is controlled, a similar effect can be obtained.

As shown in FIG. 5, a voltage transformer 20. fl
It is clear that the same effect can be obtained even if the il current transformer 19 is derived from the output of the variable speed generator. That is, in this case, since the output fluctuation of the synchronous machine 100 is detected, it is possible to prevent the power fluctuation caused by the synchronous machine 100 itself from affecting the grid.

〔Effect of the invention〕

According to the present invention, it is possible to adjust the synchronous machine output according to an external power command signal even during pumping operation, and power system control such as AFC (automatic frequency control), which was previously impossible, can be applied. It becomes possible. Furthermore, it is possible to suppress fluctuations in the power system, which can contribute to improving the stability of the power system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing an outline of a variable speed power generation device, Fig. 3 is a block diagram showing a configuration diagram of an active power calculation section, and Fig. 4 is a block diagram showing an outline of the variable speed power generation device. An explanatory diagram showing the effects of the invention, FIG. 5 is a block diagram showing another embodiment. 100...Synchronous machine, 1...Stator, 2...Rotor, 5a to 5c...-Secondary winding, 6a to 6c...Secondary winding, 11...Speed detector , 12... guide valve, 13
...Water wheel. 50...Control unit, 14...Valve opening setting device, 15...
- Command value calculation unit, 16... Phase angle calculation unit, 17...
Excitation amount setting section, 18... Voltage adjustment section, 19... Current transformer. 2o... Voltage transformer, 21... Active power calculation unit, 2
4...Current transformer, 25...Voltage transformer, 26...
- Active power change amount calculation section, 27... Reactive power change amount calculation section, 28... Correction section.

Claims (1)

[Claims] A variable speed power generation device using a synchronous machine having one- and three-phase secondary windings, comprising: a power fluctuation detection unit that detects a power fluctuation amount in a power system; A variable speed power generator comprising: a control section that controls the phase angle or absolute value of the excitation voltage applied to the secondary excitation winding of the synchronous machine according to the control section. 2. The variable speed power generation device according to claim 1, wherein the power fluctuation detection section detects a power fluctuation value of a power system to which the variable linked power generation device is connected. . 3. The variable speed power generation device according to claim 1, wherein the power fluctuation detection section detects a fluctuation value of the output power of the variable linked power generation device itself. 4. In the device according to claim 1, the power fluctuation detection section detects a power fluctuation value of a power system to which the variable speed power generation device is connected and a fluctuation value of the output power of the variable speed power generation device itself. A variable speed power generation device characterized by: 5. Claims 1, 2, 3, or 4
In the device described in 1., the power fluctuation detection section detects an active power component and a reactive power component, and the control section controls the phase angle of the secondary excitation voltage based on the active power detection value, and controls the phase angle of the secondary excitation voltage based on the reactive power detection value. 1. A variable speed power generation device, characterized in that it controls the absolute value of the next excitation power.