JPH1080199A - Automatic voltage regulator of synchronous generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic voltage regulator capable of stably controlling the output terminal voltage of a generator, by canceling the change of an exciting power supply voltage which is caused by the change of the output terminal voltage of a sytnchrous generator. SOLUTION: The following are installed; a substracter 12 operating the errors of a detection signal of a voltage detector 10 detecting the terminal voltage of a synchronous generator and a voltage command signal of a voltage command signal generator, and divider 15 dividing the control signal of an error amplifier 13 amplifying the output of the substracter 12 by a detection signal a pulse width modulator 14 outputting an on-duty switching signal which is in proportion to the output signal of the substracter 15, a rectifier 21 converting an AC voltage outputted from the synchronous generator 1 into a DC voltage, and a voltage converter 22 supplying an exciting voltage to the field winding of the synchronous generator 1 by chopping the DC voltage outputted from the rectifier 21, in accordance with the switching signal. The divider 15 divides the control signal outputted from an error amplifier 13 by a detected signal, so that the change of an exciting power supply voltage is canceled when the terminal voltage of the synchronous generator 1 changes. Thereby, the terminal voltage of the synchronous generator 1 is adjusted to be a desired value and stably controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically controls the output terminal voltage of a synchronous generator or a brushless synchronous generator to a desired voltage while utilizing the output terminal voltage of the generator as an excitation power supply voltage of the generator. The present invention relates to an automatic voltage regulator for a synchronous generator.

[0002]

2. Description of the Related Art FIG. 4 is a configuration diagram of a conventional power generator.
In the figure, 1 is a synchronous generator, and 2 is an automatic voltage regulator. The automatic voltage regulator 2 operates the voltage _Vf applied to the field winding of the synchronous generator 1 to control the synchronous generator 1
Is an apparatus for automatically controlling the output terminal voltage _Vg of the device to a desired voltage.

An automatic voltage regulator 2 detects a voltage at an output terminal of the synchronous generator 1 and outputs a detection signal A.
0 and a voltage command signal generator 1 that generates a voltage command signal B
1, a subtractor 12 for calculating an error between the detection signal A and the voltage command signal B, an error amplifier 13 for amplifying an error signal C output from the subtractor 12, and a control signal D output from the error amplifier 13. A pulse width modulator 14 for outputting an on-duty switching signal E, a transformer 20 for stepping down an output terminal voltage of the synchronous generator 1, and a rectifier 21 for converting an AC voltage supplied from the transformer 20 to a DC voltage. A voltage converter 22 that supplies an exciting voltage to the field winding of the synchronous generator 1 by turning on / off the transistor based on the switching signal E and chopper-operating the DC voltage supplied from the rectifier 21. It is configured. Such a power generator uses the output terminal voltage of the synchronous generator as a power source for the excitation voltage of the synchronous generator, and is called a shunt excitation type power generator.

FIG. 5 is a control block diagram showing the behavior of the power generating apparatus shown in FIG. 4. The same parts as those in FIG. 4 are denoted by the same reference numerals, and A to F, V _f (pu. .), V
_g (pu) signals are all p. u. Indicates a value.

In FIG. 1, a voltage detector 10 outputs a detection signal A of the output terminal voltage of the synchronous generator 1, and a voltage command signal generator 11 outputs a voltage command signal B. The subtracter 12 calculates an error between the detection signal A and the voltage command signal B to output an error signal C, the error amplifier 13 amplifies the error signal C and outputs a control signal D, and the pulse width modulator 14 controls An on-duty F switching signal proportional to the signal D is output.

The multiplier 30 represents the function of the voltage converter 22 shown in FIG.
And the output terminal voltage _Vg of the synchronous generator 1 u. Value V
_g (pu), and the field voltage V _f of the synchronous generator 1
P. u. Output the value V _f (pu). That is,
The excitation voltage V _f (pu) of the synchronous generator 1 is given by V _f (pu) = V _g (pu) × F. When the function and f _14, is given by F = D × f _14. Therefore, the function from the control signal D to the excitation voltage V _f (pu) of the synchronous generator 1 is as follows: V _f (pu) = D × f ₁₄ × V _g (pu). .

[0007] As described above, the excitation circuit of the generator of the shunt excitation method, the voltage converter 22, the switching signal F output from the output terminal voltage V _g and the pulse width modulator 14 of the synchronous generator 1 As shown in FIG. 5, a multiplier 30 is included in the control block diagram to perform a function equivalent to the function of multiplying.

In FIG. 4, the functions of a voltage detector 10, a voltage command signal generator 11, a subtractor 12, an error amplifier 13, and a pulse width modulator 14 are implemented by a microcomputer and software executed by the microcomputer. Can be realized. Further, a brushless synchronous generator may be connected to the automatic voltage regulator 2 instead of the synchronous generator 1.

FIG. 6 is a configuration diagram of another conventional power generator. This embodiment is different from the power generator shown in FIG. 4 in that the configuration of the automatic voltage regulator 3 of this embodiment is different from that of the automatic voltage regulator 2 of FIG. Instead of providing a rectifier 21 and a voltage converter 22 for operation, a voltage converter 23 for chopper-operating an AC voltage supplied from a transformer 20 with a transistor or a thyristor is provided, and the other points are the same. ,
The same portions are denoted by the same reference numerals, and redundant description will be omitted.

The automatic voltage regulator 3 of this embodiment operates the generator excitation voltage by chopper-operating the AC voltage supplied from the transformer 20 with a transistor or a thyristor as described above. The voltage converter 23 is configured to perform the function of a multiplier, just like the automatic voltage regulator 2 of No. 4.

[0011]

[SUMMARY OF THE INVENTION In the above-described conventional power plant, vary the output terminal voltage V _g is a synchronous generator or brushless synchronous generator, an automatic voltage regulator attempts to automatic control for variation suppression In this case, the excitation power supply voltage also changes at the same time, so that the excitation voltage _Vf includes an error corresponding to the change in the output terminal voltage of the synchronous generator or the brushless synchronous generator. That is, in FIG. 5, the automatic voltage regulator 2 cannot output the excitation voltage V _f (pu) of the synchronous generator or the brushless synchronous generator in proportion to the control signal D output from the error amplifier 13.

In general, the design of the stability of the control system is often performed on a Bode line, but the Bode diagram is established for a linear control system. Thus, this method is not effective for a nonlinear control system including a multiplier.

However, usually, the fluctuation of the excitation power supply voltage accompanying the fluctuation of the output terminal voltage of the synchronous generator or the brushless synchronous generator as described above is ignored, and the constant excitation power supply voltage is always approximated to be constant. The design is often done on a diagram. In such a case, the designer cannot clearly understand how much the error due to the fluctuation of the excitation power supply voltage actually affects the stability of the control system. Alternatively, the generator voltage may become unstable during operation of the brushless synchronous generator.

The present invention (corresponding to claims 1 to 8) provides:
In order to eliminate the drawbacks of the above-mentioned conventional shunt excitation type automatic voltage regulator, fluctuations in the excitation power supply voltage due to fluctuations in the output terminal voltage of the synchronous generator or brushless synchronous generator are offset, and the automatic voltage regulator is adjusted. It is an object of the present invention to provide an automatic voltage regulator of a synchronous generator capable of controlling the generator output terminal voltage more stably than the prior art by obtaining a generator excitation voltage proportional to the control signal of the generator. .

[0015]

To achieve the above object, a first aspect of the present invention is a voltage detector for detecting a terminal voltage of a synchronous generator, and a voltage command signal generator for generating a voltage command signal. A subtractor for calculating an error between a detection signal output from the voltage detector and a voltage command signal output from the voltage command signal generator; an error amplifier for amplifying an error signal output from the subtractor; A divider that divides the control signal output by the amplifier by the detection signal, a pulse width modulator that outputs an on-duty switching signal proportional to the output signal of the divider, and an AC voltage output by the synchronous generator. A rectifier for converting to a DC voltage, and a DC voltage output from the rectifier is chopper-operated by a switching element that is opened and closed according to the switching signal, thereby generating the synchronous power And a voltage converter that supplies an excitation voltage to the field winding of the synchronous generator.By dividing the control signal output from the error amplifier by the detection signal, the terminal voltage of the synchronous generator fluctuated. In this case, the terminal voltage of the synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

According to a second aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the first aspect, a brushless synchronous generator is connected instead of the synchronous generator, and a terminal voltage of the brushless synchronous generator is reduced. In the case of fluctuation, the terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

According to a third aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the first aspect, the rectifier for rectifying the AC voltage output from the synchronous generator is not required, and the AC voltage is switched. A voltage converter for supplying an excitation voltage to the field winding of the synchronous generator by chopper operation with the element, and when the terminal voltage of the synchronous generator fluctuates due to the voltage converter, the excitation power supply voltage is canceled. Meanwhile, the terminal voltage of the synchronous generator is adjusted to a desired voltage.

According to a fourth aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the third aspect, the terminal voltage of the brushless synchronous generator is connected to a brushless synchronous generator instead of the synchronous generator. In the case of fluctuation, the terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

According to a fifth aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the first aspect, the voltage command signal generator, the subtractor, the error amplifier, the divider, and the pulse width modulator are provided. Are realized by the microcomputer and the software executed by the microcomputer, and when the terminal voltage of the synchronous generator fluctuates, the terminal voltage of the synchronous generator is set to a desired value while canceling the fluctuation of the excitation power supply voltage. It is characterized in that the voltage is adjusted.

According to a sixth aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the fifth aspect, a brushless synchronous generator is connected instead of the synchronous generator, and a terminal voltage of the brushless synchronous generator is reduced. In the case of fluctuation, the terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

According to a seventh aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the fifth aspect, the rectifier for rectifying the AC voltage output from the synchronous generator is not required, and the AC voltage is switched by a switching element. A voltage converter for supplying an exciting voltage to the field winding of the synchronous generator by operating the chopper at the time, when the terminal voltage of the synchronous generator fluctuates,
It is characterized in that the terminal voltage of the synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

According to an eighth aspect of the present invention, in the automatic voltage regulator for a synchronous generator according to the seventh aspect, the terminal voltage of the brushless synchronous generator is connected to a brushless synchronous generator instead of the synchronous generator. In the case of fluctuation, the terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while canceling the fluctuation of the excitation power supply voltage.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an embodiment (corresponding to claims 1, 2, 5, and 6) of the present invention. As shown in FIG.
The only difference from the conventional power generator is that a divider 15 for dividing a control signal D output from an error amplifier 13 by a detection signal A output from a voltage detector 10 is provided, and other configurations are the same. Therefore, the same portions are denoted by the same reference numerals, and redundant description will be omitted.

The voltage command generator 11, the subtractor 12, and the error amplifier 13 are included in the automatic voltage regulator 2.
The function of each component of the pulse width modulator 14 and the divider 15 may be realized by a microcomputer and software executed by the microcomputer.

FIG. 3 is a block diagram showing the behavior of the automatic voltage regulator of the synchronous generator or the brushless synchronous generator shown in FIG. In the figure, a voltage detector 10 outputs a detection signal A of an output terminal voltage of the synchronous generator 1, and a voltage command signal generator 11 outputs a voltage command signal B. Subtractor 1
2 calculates an error between the detection signal A and the voltage command signal B to output an error signal C, an error amplifier 13 amplifies the error signal C and outputs a control signal D, and a divider 15 detects the control signal D The signal H divided by the signal A is output. Pulse width modulator 1
4 outputs a switching signal having an on-duty F ′ proportional to the signal H output from the divider 15. The multiplier 30 is a representation of the function of the voltage converter 22 of FIG. 1, p of the output terminal voltage V _g of the ON switching signal duty F 'and the synchronous generator 1. u. Multiplied by the value V _g (p.u.), and the field voltage V _f of the synchronous generator 1 is p. u. Value V _f (p.
u. ) Is output.

Next, the operation of this embodiment will be described.
Normally, in a steady state, the output terminal voltage V _g (pu) of the synchronous generator 1 or the brushless synchronous generator is controlled to be the voltage command signal B output from the voltage command signal generator 11. , The error signal C is zero. If V _g (pu) fluctuates at a certain time, an error occurs between the voltage command signal B and the detection signal A, and the error signal C is output from the subtractor 12. The error amplifier 13 amplifies the error signal C and outputs a control signal D. The divider 15 divides the control signal D by the detection signal A and outputs a phase signal H. The pulse width modulator 14 outputs a square wave switching signal having an on-duty F ′ proportional to the phase signal H. Multiplier 3
0 indicates the function of the voltage converter 22 of FIG. 1, by multiplying the on-duty F 'of the switching signal output of the pulse width modulator 14 to the generator output terminal voltage V _g (p.u.), synchronous The excitation voltage V is applied to the field winding of the generator 1.
_f (pu).

By the above operation, even when the generator output terminal voltage fluctuates, the fluctuation of the excitation power supply voltage of the synchronous generator is canceled. That is, in FIG. 3, the excitation voltage V of the synchronous generator 1 or the brushless synchronous generator is
_f (pu) is given by the following equation.

V _f (p.u.) = V _g (p.u.) × F ′ Further, if the function of the pulse width modulator 14 is f ₁₄ , the on-duty F ′ is

(Equation 1) Given by Here, since A = V _g (p.u.), the excitation voltage V _f (p.
u. ) Function _{until, V f (p.u.) =} D × f 14 becomes, V _g (p.u.) is canceled, the excitation voltage V _f (p of the synchronous generator that is proportional to the control signal D. u.) is obtained.

FIG. 2 is a block diagram of another embodiment of the present invention (corresponding to claims 3, 4, 7, and 8). The difference between the present embodiment and the power generator of FIG. 1 is that the configuration of the automatic voltage regulator 3 of the present embodiment is such that the automatic voltage regulator 2 of FIG. 1 performs a chopper operation on the AC voltage supplied from the transformer 20. Instead of providing the rectifier 21 and the voltage converter 22, a voltage converter 23 for chopper-operating an AC voltage supplied from the transformer 20 with a transistor or a thyristor is provided. The same parts are denoted by the same reference numerals, and redundant description will be omitted.

As described above, in the automatic voltage regulator 3 of the synchronous generator or the brushless synchronous generator of this embodiment, the rectifier 21 for chopper-operating the AC voltage supplied from the transformer 20 as shown in FIG. Only the point that a voltage converter 23 that operates a chopper by a transistor or a thyristor is provided instead of providing the converter 22 is different from the embodiment of FIG. 1, and its behavior is similar to that of the control block of FIG. 3. The description is omitted.

[0031]

As described above, the present invention (Claim 1)
According to claim 8), when the output terminal voltage of the synchronous generator of the shunt excitation system is controlled by the automatic voltage regulator, the fluctuation of the excitation power supply voltage accompanying the fluctuation of the output terminal voltage of the synchronous generator is canceled. However, since the synchronous generator field voltage can be obtained in proportion to the control signal of the automatic voltage regulator, the synchronous generator output terminal voltage can be more stably controlled than in the related art.

In addition, since the function of the multiplier included in the synchronous generator of the shunt-excitation system is basically eliminated, the control system becomes a linear system, and the control design on the Bode diagram becomes effective. It is possible to make the power generation device easy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of another embodiment of the present invention.

FIG. 3 is a control block diagram showing a behavior of the embodiment of FIG. 1;

FIG. 4 is a configuration diagram of a conventional power generation device.

FIG. 5 is a control block diagram showing the behavior of the conventional power generator of FIG.

FIG. 6 is a configuration diagram of another conventional power generation device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Synchronous generator, 2 ... Automatic voltage regulator, 10 ... Voltage detector, 11 ... Voltage command generator, 12 ... Subtractor, 13 ... Error amplifier, 14 ... Pulse width modulator, 15 ... Divider, 20 ...
Transformers, 21 rectifiers, 22, 23 voltage converters.

Claims (8)

[Claims] 1. A voltage detector for detecting a terminal voltage of a synchronous generator, a voltage command signal generator for generating a voltage command signal, a detection signal output by the voltage detector, and an output of the voltage command signal generator Subtractor for calculating the error of the voltage command signal to be applied, an error amplifier for amplifying the error signal output from the subtractor, a divider for dividing the control signal output from the error amplifier by the detection signal, and the divider A pulse width modulator that outputs an on-duty switching signal proportional to the output signal of the synchronous generator, a rectifier that converts an AC voltage output from the synchronous generator into a DC voltage, and a DC voltage output by the rectifier according to the switching signal. A voltage converter that supplies an exciting voltage to a field winding of the synchronous generator by operating a chopper by a switching element that is opened and closed; When the divider divides the control signal output from the error amplifier by the detection signal, when the terminal voltage of the synchronous generator fluctuates, the terminal voltage of the synchronous generator is reduced while canceling the fluctuation of the excitation power supply voltage. An automatic voltage regulator for a synchronous generator, wherein the voltage is regulated to a desired voltage. 2. The automatic voltage regulator for a synchronous generator according to claim 1, wherein said automatic generator is connected to a brushless synchronous generator instead of said synchronous generator, and is excited when a terminal voltage of said brushless synchronous generator fluctuates. An automatic voltage regulator for a synchronous generator, wherein a terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while offsetting a fluctuation in a power supply voltage. 3. The automatic voltage regulator of a synchronous generator according to claim 1, wherein said AC voltage is chopper-operated by a switching element without requiring said rectifier for rectifying an AC voltage output by said synchronous generator. A voltage converter for supplying an excitation voltage to a field winding of the synchronous generator, and when the terminal voltage of the synchronous generator fluctuates with the voltage converter, the synchronous generator An automatic voltage regulator for a synchronous generator, wherein the terminal voltage of the synchronous generator is adjusted to a desired voltage. 4. The automatic voltage regulator of a synchronous generator according to claim 3, wherein said automatic generator is connected to a brushless synchronous generator instead of said synchronous generator, and is excited when a terminal voltage of said brushless synchronous generator fluctuates. An automatic voltage regulator for a synchronous generator, wherein a terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while offsetting a fluctuation in a power supply voltage. 5. The automatic voltage regulator of a synchronous generator according to claim 1, wherein each function of said voltage command signal generator, said subtractor, said error amplifier, said divider, and said pulse width modulator is a microcontroller. It is realized by a computer and software executed by the microcomputer, and when the terminal voltage of the synchronous generator fluctuates, adjusts the terminal voltage of the synchronous generator to a desired voltage while canceling the fluctuation of the excitation power supply voltage. Features automatic voltage regulator of synchronous generator. 6. The automatic voltage regulator of a synchronous generator according to claim 5, wherein the brushless synchronous generator is connected to a brushless synchronous generator instead of the synchronous generator, and is excited when a terminal voltage of the brushless synchronous generator fluctuates. An automatic voltage regulator for a synchronous generator, wherein a terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while offsetting a fluctuation in a power supply voltage. 7. The automatic voltage regulator for a synchronous generator according to claim 5, wherein the rectifier for rectifying the AC voltage output from the synchronous generator is not required, and the AC voltage is chopper-operated by a switching element. A voltage converter for supplying an excitation voltage to the field winding of the synchronous generator, wherein when the terminal voltage of the synchronous generator fluctuates, the terminal voltage of the synchronous generator is reduced while canceling the fluctuation of the excitation power supply voltage. An automatic voltage regulator for a synchronous generator, wherein the voltage is regulated to a desired voltage. 8. The automatic voltage regulator for a synchronous generator according to claim 7, wherein said automatic generator is connected to a brushless synchronous generator instead of said synchronous generator, and is excited when a terminal voltage of said brushless synchronous generator fluctuates. An automatic voltage regulator for a synchronous generator, wherein a terminal voltage of the brushless synchronous generator is adjusted to a desired voltage while offsetting a fluctuation in a power supply voltage.