JP2020137262A - Exciting arrangement of synchronous machine and excitation method - Google Patents

Abstract

To provide an excitation arrangement of a synchronous machine, capable of performing a stable limitation control when performing an over-current limit control.SOLUTION: An exciting arrangement of a synchronous machine, comprises: voltage adjustment means of adjusting an AC output voltage of the synchronous machine so as to be matched to a voltage setting value; and armature current limitation means of controlling the armature current so as to be returned to a current limitation setting value when the armature current of the synchronous machine exceeds a preset overcurrent setting value. The armature current limitation means comprises: stabilization signal generation means of outputting a changed portion of an effective current signal as a stabilization signal; stabilization current deviation signal generation means of outputting a value obtained by subtracting the current limitation setting value and further the stabilization signal from the value of a signal of the armature current as a stabilization current deviation signal; and amplification means of supplying to the voltage adjustment means the signal obtained by selecting and amplifying the signal of a low value from the stabilization current deviation signal and a prescribed signal as an excitation enhanced signal of the synchronous machine.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to an exciting device and an exciting method of a synchronous machine.

One of the functions of the exciter of the synchronous machine is an overcurrent limiting function that limits the armature current so as not to exceed the withstand capacity of the synchronous machine.

The general overcurrent limiting function reduces the field voltage of the synchronous machine during slow-phase operation, and conversely increases the field voltage of the synchronous machine during phase-advance operation to reduce the armature current of the synchronous machine. I have to.

Japanese Unexamined Patent Publication No. 58-218899 Japanese Unexamined Patent Publication No. 6-133599 Japanese Unexamined Patent Publication No. 8-116679 JP-A-2018-007484

In general, the overcurrent limiting function is a deviation (hereinafter, "armature current Ig") between a signal indicating a current limit setting value for an armature current (hereinafter, "armature current limit setting signal IL") and an armature current (hereinafter, "armature current Ig"). = IL-Ig) (hereinafter, "armature current deviation signal ΔIg") is used to increase or decrease the field voltage to bring the armature current deviation signal ΔIg closer to 0, but during phase advance operation Since the field voltage is increased or decreased by −ΔIg (= Ig−IL), a negative braking phenomenon may be caused by the action of the active current included in the armature current Ig.

The armature current Ig is expressed by the following equation using an active current (hereinafter, “active current IP”) and a reactive current (hereinafter, “reactive current IQ”).

Ig = (IP ² + IQ ² ) ^1/2 ... (1)
The following equation is obtained by partially differentiating the armature current Ig with respect to the effective current IP in equation (1).

∂Ig / ∂IP = 1/2 ・ 2 ・ IP ・ (IP ² + IQ ² ) ^-1 / ² = IP / Ig… (2)
From equation (2), it can be seen that the armature current Ig contains a component that changes in proportion to the effective current IP.

When the overcurrent limit control is performed in the exciting device of the synchronous machine, the armature current deviation signal ΔIg is amplified to perform the excitation control, but the excitation control is performed by a signal proportional to the effective current IP included in the armature current. If this is done, the braking force of the control system may decrease and the control system may become unstable. In particular, when overcurrent limiting control is performed in the phase advance region, the excitation control output is increased or decreased according to the increase or decrease of the active current IP, so that the control system tends to become unstable.

An object of the present invention to be solved is to provide an exciting device and an exciting method for a synchronous machine, which can perform stable limiting control when performing overcurrent limiting control in the exciting device of the synchronous machine.

The exciter of the synchronous machine according to the embodiment includes a voltage adjusting means for adjusting the AC output voltage of the synchronous machine so as to match the voltage set value, and the armature current of the synchronous machine exceeds a predetermined overcurrent set value. The armature current limiting means for controlling the armature current to be pulled back to a predetermined current limit set value is provided. The armature current limiting means includes an effective current detecting means for detecting the effective current signal of the synchronous machine, an armature current detecting means for detecting the armature current signal of the synchronous machine, and a change in the effective current signal. A stabilizing signal generating means that outputs as a stabilizing signal and a value obtained by subtracting the current limit set value from the value of the armature current signal and further subtracting the value of the stabilizing signal are used as a stabilizing current deviation signal. The voltage adjusting means uses the stabilized current deviation signal generating means to be output and the signal obtained by selecting and amplifying the stabilized current deviation signal and the low value signal among the predetermined signals as the excitation strengthening signal of the synchronous machine. It is provided with an amplification means for supplying the current.

According to the present invention, stable limiting control can be performed when overcurrent limiting control is performed in the exciting device of the synchronous machine.

The figure which shows the structure of the exciter of the synchronous machine which concerns on 1st Embodiment. The conceptual diagram for demonstrating the armature current limiting action in the same embodiment. The figure which shows the structure of the exciter of the synchronous machine which concerns on 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.

[First Embodiment]
First, the first embodiment will be described with reference to FIGS. 1 and 2.

(Constitution)
FIG. 1 is a diagram showing a configuration of an exciting device of the synchronous machine according to the first embodiment.

Reference numeral 1 denotes a synchronous machine, which is an armature winding (also called a stator winding) 1A wound around a stator core and a field winding 1B wound around a magnetic pole core fixed to a rotor rim. The field current If is supplied to the field winding 1B from the exciting power source on the stationary portion side via the sliding contact portion 2 including the slip ring and the brush.

In the main circuit of the synchronous machine 1, 3 is a main transformer that boosts the voltage generated by the synchronous machine 1 to the system voltage, and 4 is a parallel circuit breaker that connects the synchronous machine 1 to the power system 5.

Further, in the field circuit of the synchronous machine 1, 6 is a thyristor for rectifying the AC power supplied from the synchronous machine 1 via the exciting transformer 7 and supplying the field current If to the field winding 1B. It is a rectifier. Reference numeral 8 denotes an automatic voltage regulator (AVR) that adjusts the AC output voltage Vg of the synchronous machine 1 so as to match the target value.

The automatic voltage regulator 8 includes a voltage detector 8A, an active power detector 8B, an ineffective power detector 8C, a divider 8D, a divider 8E, a current calculator 8F, a counter time timer 8G, a selector 8H, a subtractor 8J, and the like. Differentiator 8K, amplifier 8L, subtractor 8M, subtractor 8N, low value selector 8P, amplifier 8Q, subtractor 8R, low value selector 8S, amplifier 8T, voltage setter 8U, subtractor 8V, high value selector 8W , Low value selector 8X, and voltage regulator 8Y.

The voltage detector 8A detects a voltage proportional to the AC output voltage Vg of the synchronous machine 1 via the voltage transformer 9, and outputs this as an AC voltage detection value Vgd (PU value).

The active power detector 8B detects an active power signal proportional to the active power Pg of the synchronous machine 1 via the voltage transformer 9 and the instrument transformer 10, and detects this as the active power detection value Pgd (PU value). Output as.

The reactive power detector 8C detects a reactive power signal proportional to the reactive power Qg of the synchronous machine 1 via the voltage transformer 9 and the current transformer 10 for the instrument, and detects this as the reactive power detection value Qgd (PU value). Output as.

The divider 8D inputs the active power detection value Pgd and the AC voltage detection value Vgd, and outputs the value obtained by dividing the active power detection value Pgd by the AC voltage detection value Vgd as the effective current signal IPd.

The voltage detector 8A, the active power detector 8B, and the divider 8D described above constitute an effective current detecting means for detecting the active current IP of the synchronous machine 1 as an effective current signal IPd.

The divider 8E inputs the reactive power detection value Qgd and the AC voltage detection value Vgd, and outputs the value obtained by dividing the reactive power detection value Qgd of the synchronous machine 1 by the AC voltage detection value Vgd as the reactive current signal IQd. To do.

The voltage detector 8A, the reactive power detector 8C, and the reactive current 8E described above constitute a reactive current detecting means for detecting the reactive current IQ of the synchronous machine 1 as a reactive current signal IQd.

The current calculator 8F calculates the square root of the sum of the square of the value of the effective current signal IPd and the square of the value of the invalid current signal IQd, and calculates this as the armature current signal Igd proportional to the armature current Ig of the synchronous machine 1. Output as. The current calculator 8F constitutes an armature current detecting means for detecting the armature current signal Igd.

The counter-time limit timer 8G inputs the armature current signal Igd, and the integrated value of the difference between the armature current signal Igd value and the preset overcurrent set value Ioc exceeds the predetermined overcurrent limit set value Toc. Occasionally, the current limit operation signal OC is output on.

The selector 8H inputs the current limit operation signal OC, selects limit setting 1 (instantaneous current limit set value) when the current limit operation signal OC is off, and on the other hand, when the current limit operation signal OC is on. Limit setting 2 (timed current limit set value) is selected, and the selected one is output as the limit setting signal IL.

A threshold value for instantaneously limiting the armature current Ig of the synchronous machine 1 is applied to the limit setting 1, and the armature current Ig of the synchronous machine 1 is delayed by the overcurrent time limit set value Toc to the limit setting 2. The threshold for holding and limiting is applied. The overcurrent set value Ioc is set to a value smaller than the limit setting 1, and the limit setting 2 is set to a value smaller than the overcurrent set value Ioc. That is, the relationship of "limit setting 2 <Ioc <limit setting 1" is set to hold.

The subtractor 8J inputs the armature current signal Igd and the limit setting signal IL, and outputs a value obtained by subtracting the value of the limit setting signal IL from the value of the armature current signal Igd as the current deviation signal Ie. That is, the subtractor 8J inputs the armature current signal Igd proportional to the armature current Ig of the synchronous machine 1 and the limit setting signal IL indicating the level of limiting the current, and outputs the difference as the current deviation signal Ie. To do.

The differentiator 8K inputs the effective current signal IPd and outputs the value obtained by inexact differential of the effective current signal IPd as the effective current deviation signal dIP.

The amplifier 8L inputs the effective current deviation signal dIP, and outputs a value obtained by multiplying the value of the effective current deviation signal dIP by a predetermined gain as a stabilization signal STB.

The above-mentioned differentiator 8K and amplifier 8L constitute a stabilization signal generation means that outputs a change in the effective current signal IPd (a component proportional to the fluctuation of the effective current that causes a negative braking phenomenon) as a stabilization signal STB.

The subtractor 8M inputs the current deviation signal Ie and the stabilization signal STB, and outputs a value obtained by subtracting the value of the stabilization signal STB from the value of the current deviation signal Ie as the stabilization current deviation signal Eyes.

The above-mentioned counter-time limit timer 8G, selector 8H, subtractor 8J, and subtractor 8M have a limit setting 1 (instantaneous current limit setting value) or a limit setting 2 value (timed current limit setting) from the value of the armature current signal Igd. The value) is subtracted, and the value obtained by further subtracting the value of the stabilization signal STB is output as the stabilization current deviation signal Eyes, which constitutes a stabilizing current deviation signal generation means.

The subtractor 8N inputs a predetermined threshold value (phase advance side dead zone set value) DB1 and an invalid power detection value Qgd as a boundary of the phase advance side dead zone, and detects the invalid power from the phase advance side dead band set value DB1. The value obtained by subtracting the value Qgd is output as the phase advance side dead zone deviation signal DBe1.

The low value selector 8P inputs the stabilized current deviation signal Ies and the phase-advancing side dead zone deviation signal DBe1, and outputs the signal obtained by selecting the low value as the phase-advancing side current deviation signal Ied.

The amplifier 8Q inputs the phase-advancing side current deviation signal Ied, and outputs a value obtained by multiplying the value of the phase-advancing side current deviation signal Ied by a predetermined positive gain as the phase-advancing side current limiting signal Ild.

The low value selector 8P and the amplifier 8Q described above synchronize the phase advance side current limit signal Ild obtained by selecting and amplifying the low value signal among the stabilized current deviation signal Eyes and the phase advance side dead zone deviation signal DBe1. A low value selective amplification means supplied to the high value selector 8W of the voltage adjusting means 81 as an excitation strengthening signal of the machine 1 is configured.

The subtractor 8R inputs a predetermined threshold value (slow-phase side dead zone setting value) DB2 as a boundary between the negative power detection value Qgd and the slow-phase side dead zone of the negative power, and sets the slow-phase side dead zone from the negative power detection value Qgd. The value obtained by subtracting the value DB2 is output as the late phase insensitive band deviation signal DBe2.

The low value selector 8S inputs the current deviation signal Ie and the slow phase side dead zone deviation signal DBe2, and outputs the signal obtained by selecting the low value as the late phase side current deviation signal Ieg.

The amplifier 8T outputs a value obtained by multiplying the value of the slow-phase side current deviation signal Ieg by a predetermined negative gain as the slow-phase side current limiting signal Ilg.

The low value selector 8S and the amplifier 8T described above synchronize the slow phase side current limiting signal Ilg obtained by selecting the low value signal from the current deviation signal Ie and the slow phase side dead zone deviation signal DBe2 and amplifying the sign inversion. A low value selective amplification means supplied to the low value selector 8X of the voltage adjusting means 81 as an excitation weakening signal of the machine 1 is configured.

The voltage setter 8U outputs a predetermined voltage set value Vr.

The subtractor 8V outputs a value obtained by subtracting the AC voltage detection value Vgd from the voltage set value Vr as a voltage deviation signal Ve.

The high value selector 8W inputs the voltage deviation signal Ve and the phase advance side current limiting signal Ild, and outputs the signal obtained by selecting the high value as the voltage deviation signal Ve2. That is, the high price selector 8W supplies the signal obtained by selecting the high price to the voltage regulator 8Y side as a new voltage deviation signal.

The low value selector 8X inputs the voltage deviation signal Ve2 and the slow phase side current limiting signal Ilg, and outputs the value obtained by selecting the low value as the voltage deviation signal Ve3. That is, the low value selector 8X supplies the value obtained by selecting the low value to the voltage regulator 8Y side as a new voltage deviation signal.

The voltage regulator 8Y inputs the voltage deviation signal Ve3 and outputs the gate signal P of the thyristor rectifier 6 at a timing corresponding to the phase control signal α that amplifies the voltage deviation signal Ve3. That is, the voltage regulator 8Y controls the timing of the gate signal P supplied to the thyristor rectifier 6 so that the voltage deviation signal Ve3 becomes 0.

In FIG. 1, reference numeral 81 denotes a basic part (voltage adjusting means) of a voltage adjusting function for adjusting the AC output voltage Vg of the synchronous machine 1 so as to match a target value, and the voltage setter 8U, the subtractor 8V, described above. Includes high value selector 8W, low value selector 8X, and voltage regulator 8Y.

On the other hand, 80 controls the armature current to be pulled back to the limit setting 2 (timed current limit set value) when, for example, the value of the armature current Ig of the synchronous machine 1 exceeds the overcurrent set value Ioc. It is a part (armature current limiting means) that realizes the current limiting function, etc., and is the voltage detector 8A, active power detector 8B, invalid power detector 8C, divider 8D, divider 8E, current calculator 8F, described above. Reverse time timer 8G, selector 8H, subtractor 8J, differentiator 8K, amplifier 8L, subtractor 8M, subtractor 8N, low value selector 8P, amplifier 8Q, subtractor 8R, low value selector 8S, and amplifier 8T including.

The above-mentioned phase-advancing side dead zone setting value DB1 is set with an invalid power value that does not activate the armature current limit on the slower phase side, and the slow phase side dead zone setting value DB2 is set on the phase advance side. An invalid power value is set that does not activate the armature current limit.

Further, the differentiator 8K shall be equipped with a one-stage or a plurality of stages of incomplete differentiating circuits connected in series, but if it has a function of removing the DC component of the input signal and outputting the change. , Any circuit may be used.

Further, an arbitrary fixed value may be set as the amplification gain of the amplifier 8L, but the ratio of the value of the effective current signal IPd and the value of the armature current signal Igd may be set. For example, if IP / Ig (that is, IPd / Igd) is set as the amplification gain of the amplifier 8L as can be seen from Eq. (2), the component proportional to the effective current fluctuation contained in the armature current signal Igd is removed. it can. The amplification gain of the amplifier 8L is set to a value of 1 times or less.

(Action)
In the configuration of FIG. 1, when the parallel circuit breaker 4 is turned on and the synchronous machine 1 is operating in parallel with the power system 5, if the armature current signal Igd is less than the limit setting 2, the current deviation signal Ie is generated. Since it is a negative value, the phase-advancing side current limiting signal Ild shows a negative value, and the slow-phase side current limiting signal Ilg shows a positive value. At this time, the voltage deviation signal Ve is selected by the high value selector 8W and the low value selector 8X, and is input to the voltage regulator 8Y as the voltage deviation signal Ve3. Since the voltage regulator 8Y controls the timing of the gate signal P so that the voltage deviation signal Ve3 becomes 0, the AC output voltage of the synchronous machine 1 is eventually matched so that the AC voltage detection value Vgd matches the voltage set value Vr. Vg is controlled.

FIG. 2 is a conceptual diagram for explaining the action of limiting the armature current Ig of the synchronous machine 1. In FIG. 2, the horizontal axis is the active current IP and the vertical axis is the reactive current IQ, and the operating points of the synchronous machine 1 are shown. In this example, the overcurrent setting value Ioc is 1.05 PU, the limit setting 2 is 1.0 PU, and the advance is advanced. The phase side dead zone set value DB1 is −0.1 PU, and the late phase side dead zone set value DB2 is 0.3 PU.
Here, four cases will be described.

・ "Case 1"
It is assumed that the armature current Ig of the synchronous machine 1 increases and reaches the operating point A in FIG. At this time, since the value of the armature current signal Igd exceeds the overcurrent set value Ioc, the current limit operation signal OC is turned on and output when the integrated value of the difference exceeds the overcurrent time limit set value Toc, and the limit setting is performed. The limit setting 2 is output as the limit setting signal IL instead of 1, so that the current deviation signal Ie, which is the difference between the armature current signal Igd and the limit setting signal IL, becomes a positive value.

Since the phase-advancing dead zone deviation signal DBe1 (= DB1-Qgd) is also a positive value at the operating point A, the phase-advancing current deviation signal Ied obtained by selecting a low value with the low value selector 8P and the amplifier 8Q The amplified phase-advancing current limiting signal Ild also has a positive value.

As a result, the phase-advancing current limiting signal Ild is selected as the voltage deviation signal Ve2 by the high value selector 8W, and the voltage regulator 8Y increases the field current If, so that the AC output voltage Vg and the reactive current IQ also increase. .. The active current IP decreases as the AC output voltage Vg increases when the active power Pg is constant.

In this case, since the current deviation signal Ie reaches 0 before the phase-advancing dead zone deviation signal DBe1 becomes 0, the amplifier 8Q operates at the time when the armature current Ig reaches the limit setting 2, that is, at the operating point A'. The output phase-advancing current limit signal Ild becomes 0 and settles in a steady state.

In the above description, one of the input signals of the low value selector 8P is the stabilized current deviation signal Eyes obtained by subtracting the value of the stabilizing signal STB from the value of the current deviation signal Ie, but it settles in a steady state. Since the value of the stabilization signal STB after the operation becomes 0, the operating point after the stabilization signal STB has settled in the steady state does not change.

On the other hand, during the armature current limiting operation, excitation control is performed by a signal obtained by amplifying the stabilized current deviation signal Eyes, but the stabilized signal STB has a component proportional to the effective current fluctuation that causes a negative braking phenomenon. Since it is removed from the current deviation signal Ie, stable operation can be performed without causing a negative braking phenomenon even during the armature current limiting operation.

・ "Case 2"
As another case, it is assumed that the armature current Ig of the synchronous machine 1 increases and reaches the operating point B in FIG. In this case as well, the operation is the same as in the case of the operating point A, but since the phase-advancing side dead zone deviation signal DBe1 reaches 0 before the current deviation signal Ie becomes 0, the ineffective power Qg is set to the phase-advancing side dead zone. When the value DB1 is reached, that is, at the operating point B', the phase-advancing current limiting signal Ild output by the amplifier 8Q becomes 0 and settles in a steady state.

In this case, since the excitation control is performed by the signal obtained by amplifying the invalid power deviation signal (DB1-Qg), the negative braking phenomenon does not occur if the gain is set appropriately.

・ "Case 3"
Next, as a case of slow-phase operation, it is assumed that the armature current Ig of the synchronous machine 1 increases and reaches the operation point C in FIG. At this time, since the value of the armature current signal Igd exceeds the overcurrent set value Ioc, the current limit operation signal OC is turned on and output when the integrated value of the difference exceeds the overcurrent time limit set value Toc, and the limit setting is performed. The limit setting 2 is output as the limit setting signal IL instead of 1, so that the current deviation signal Ie, which is the difference between the armature current signal Igd and the limit setting signal IL, becomes a positive value.

Since the slow-phase side dead zone deviation signal DBe2 (= Qgd-DB2) is also a positive value at the operating point C, the slow-phase side current deviation signal Ieg obtained by selecting a low value with the low value selector 8S becomes a positive value. The slow-phase current limiting signal Ilg amplified by the amplifier 8T with a negative gain has a negative value.

As a result, the slow-phase side current limiting signal Ilg is selected as the voltage deviation signal Ve3 by the low value selector 8X, and the voltage regulator 8Y reduces the field current If, so that the AC output voltage Vg and the reactive current IQ also decrease. To do. The active current IP increases as the AC output voltage Vg decreases when the active power Pg is constant.

In this case, since the current deviation signal Ie reaches 0 before the slow-phase side dead zone deviation signal DBe2 becomes 0, the amplifier 8T operates at the time when the armature current Ig reaches the limit setting 2, that is, at the operating point C'. The output slow-phase side current limiting signal Ilg becomes 0 and settles in a steady state. Further, in this case, since the excitation control is performed by the signal obtained by inverting the sign of the armature current Ig included in the current deviation signal Ie, the active current fluctuation amount included in the armature current Ig acts as a positive braking force. Therefore, the negative braking phenomenon does not occur.

・ "Case 4"
As another case, it is assumed that the armature current Ig of the synchronous machine 1 increases and reaches the operating point D in FIG. In this case as well, the operation is the same as in the case of the operating point C, but since the late phase side dead zone deviation signal DBe2 reaches 0 before the current deviation signal Ie becomes 0, the ineffective power Qg is set to the late phase side dead zone. When the value DB2 is reached, that is, at the operating point D', the slow-phase side current limiting signal Ilg output by the amplifier 8T becomes 0 and settles in a steady state.

In this case, since the excitation control is performed by the signal obtained by amplifying the invalid power deviation signal (DB2-Qg), the negative braking phenomenon does not occur if the gain is set appropriately.

(effect)
According to the first embodiment, when the armature current limit control is performed by the excitation strengthening operation, the armature current limit control is performed by removing the effective current fluctuation component included in the current deviation signal Ie by the stabilization signal STB. It is possible to prevent the negative braking phenomenon inside and realize stable limiting control.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG.

(Constitution)
FIG. 3 is a diagram showing a configuration of an exciting device of the synchronous machine according to the second embodiment.

The second embodiment is the one in which the automatic voltage regulator 8 is replaced with the automatic voltage regulator 8'in the first embodiment (FIG. 1) described above. The difference from the automatic voltage regulator 8 is that the amplifier 8L'is provided instead of the amplifier 8L.

The amplifier 8L'inputs the effective current deviation signal dIP, the effective current signal IPd, and the armature current signal Igd, and sets the value of the effective current deviation signal dIP to the value of the effective current signal IPd and the value of the armature current signal Igd. The stabilization signal STB obtained by multiplying the ratio is output. The ratio of the value of the effective current signal IPd to the value of the armature current signal Igd is applied to the amplification gain of the amplifier 8L'.

(Action)
The difference from the first embodiment is that the gain of the amplifier 8L'is made variable according to the operating state.

As described above, the amplification gain of the amplifier 8L'is set to IP / Ig (that is, IPd / Igd) represented by the equation (2). As a result, the component proportional to the fluctuation of the effective current contained in the armature current Ig is removed.

Therefore, the amplifier 8L'generates a stabilization signal STB having a magnitude sufficiently large to remove the effective current fluctuation component included in the armature current signal Igd even if the operating state of the synchronous machine 1 changes.

(effect)
According to the second embodiment, in addition to the effect of the first embodiment, when the armature current limit control is performed by the excitation strengthening operation, the effective current fluctuation component included in the current deviation signal Ie is set in all operating states. Since it can be removed by a stabilization signal STB having a necessary and sufficient magnitude, it is possible to prevent a negative braking phenomenon during armature current limit control and realize stable limit control.

As described in detail above, according to each embodiment, stable limiting control can be performed when overcurrent limiting control is performed in the exciting device of the synchronous machine.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Synchronous machine, 1A ... Armor winding, 1B ... Field winding, 2 ... Sliding contact part, 3 ... Main transformer, 4 ... Parallel circuit breaker, 5 ... Power system, 6 ... Cylister rectifier, 7 ... Excitation transformer, 8 ... Automatic voltage regulator, 8'... Automatic voltage regulator, 8A ... Voltage detector, 8B ... Active power detector, 8C ... Invalid power detector, 8D ... Divider, 8E ... Divider , 8F ... current calculator, 8G ... counter-time timer, 8H ... selector, 8J ... subtractor, 8K ... differential, 8L ... amplifier, 8L'... amplifier, 8M ... subtractor, 8N ... subtractor, 8P ... low Value selector, 8Q ... amplifier, 8R ... subtractor, 8S ... low value selector, 8T ... amplifier, 8U ... voltage setter, 8V ... subtractor, 8W ... high value selector, 8X ... low value selector, 8Y ... Voltage regulator, 9 ... Instrument transformer, 10 ... Instrument transformer, 80 ... Armature current limiting means, 81 ... Voltage adjusting means.

Claims (6)

A voltage adjusting means for adjusting the AC output voltage of the synchronous machine so as to match the voltage set value, and a predetermined armature current when the armature current of the synchronous machine exceeds a predetermined overcurrent set value. Equipped with an armature current limiting means that controls to pull back to the current limit set value,
The armature current limiting means is
The effective current detecting means for detecting the effective current signal of the synchronous machine and
An armature current detecting means for detecting an armature current signal of the synchronous machine, and
A stabilizing signal generating means that outputs a change in the effective current signal as a stabilizing signal,
A stabilized current deviation signal generating means that subtracts the current limit set value from the value of the armature current signal and further subtracts the value of the stabilized signal to output a value obtained as a stabilized current deviation signal.
Amplifying means for supplying the regulated current deviation signal and a signal obtained by selecting and amplifying a low value signal among predetermined signals to the voltage adjusting means as an excitation strengthening signal of the synchronous machine.
The exciter of the synchronous machine equipped with. A voltage adjusting means for adjusting the AC output voltage of the synchronous machine so as to match the voltage set value, and a predetermined armature current when the armature current of the synchronous machine exceeds a predetermined overcurrent set value. Equipped with an armature current limiting means that controls to pull back to the current limit set value,
The armature current limiting means is
An ineffective power detecting means for obtaining an ineffective power detection value from the inactive power of the synchronous machine, and
The effective current detecting means for detecting the effective current signal of the synchronous machine and
An armature current detecting means for detecting an armature current signal of the synchronous machine, and
A stabilizing signal generating means that outputs a change in the effective current signal as a stabilizing signal,
A current deviation signal generating means that outputs a value obtained by subtracting the current limit set value from the value of the armature current signal as a current deviation signal.
A regulated current deviation signal generating means that outputs a value obtained by subtracting the value of the stabilized signal from the value of the current deviation signal as a stabilized current deviation signal.
A subtraction means that outputs a value obtained by subtracting the disabled power detection value from a predetermined phase-advancing dead zone setting value as a boundary of the phase-advancing dead zone of the dead power as a phase-advancing dead zone deviation signal.
The slow-phase side current limiting signal obtained by selecting and amplifying the low value signal among the stabilized current deviation signal and the phase-advancing side dead zone deviation signal is used as the excitation strengthening signal of the synchronous machine in the automatic voltage adjusting means. Low value selective amplification means to supply and
A subtraction means that outputs a value obtained by subtracting a predetermined slow-phase side dead zone set value as a boundary of the slow-phase side dead zone of the negative power from the negative power detection value as a slow-phase side dead band deviation signal.
The slow-phase side current limiting signal obtained by selecting a low-value signal from the current deviation signal and the slow-phase side dead zone deviation signal and inverting and amplifying the sign is used as the excitation weakening signal of the synchronous machine in the automatic voltage adjusting means. Low value selective amplification means to supply and
The exciter of the synchronous machine equipped with. The stabilized signal generating means includes one stage or a plurality of stages of incomplete differential circuits connected in series.
The exciter for the synchronous machine according to claim 1 or 2. The stabilized signal generating means includes a one-stage or a plurality of stages of incomplete differential circuits connected in series, and an amplification means in which an arbitrary fixed value is set as a gain.
The exciter for the synchronous machine according to claim 1 or 2. The stabilized signal generating means is an amplification means in which a ratio of an effective current signal value of the synchronous machine and an armature current value is set as a gain of a one-stage or a plurality of stages of incomplete differential circuits connected in series. Including,
The exciter for the synchronous machine according to claim 1 or 2. A voltage adjusting means for adjusting the AC output voltage of the synchronous machine so as to match the voltage set value, and a predetermined armature current when the armature current of the synchronous machine exceeds a predetermined overcurrent set value. It is an excitation method of a synchronous machine equipped with an armature current limiting means for controlling the return to the current limit set value.
By the armature current limiting means
The active current signal of the synchronous machine is detected,
Detecting the armature current signal of the synchronous machine,
The change in the effective current signal is output as a stabilization signal.
The value obtained by subtracting the current limit set value from the value of the armature current signal and further subtracting the value of the stabilized signal is output as a stabilized current deviation signal.
A signal obtained by selecting and amplifying the stabilized current deviation signal and a predetermined signal having a low value is supplied to the voltage adjusting means as an excitation strengthening signal of the synchronous machine.
How to excite the synchronous machine, including that.