JPS592598A - Excitation controller for synchronous machine - Google Patents

Abstract

PURPOSE:To improve the reliability of a synchronous machine by providing more than 3 automatic voltage regulators, and controlling the excitation of the mechine with the average value of the output signals of the regulators. CONSTITUTION:Three transformers 5 for instruments to step down the terminal voltage of a synchronous machine 1, three automatic voltage regulators 6 and three reference voltage settters 7 are provided, and the output signals V11-V31 of the regulators 6 are inputted to an average calculator 10. The output V0 of the average calculator is inputted to a phase controller 9, and an exciting current is supplied from a thyristor exciter 3 to the field coil 2 of the machine 1 on the basis of the firing pulse which is outputted from the controller 9. In this manner, the influence of the malfunction signal of high or low degree due to the sole defect of the previous stage of the average calculation to the machine can be reduced, and the detection of the defect can be readily and effectively performed.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an excitation control device for a synchronous machine, and more particularly to a multiplexed excitation control system that takes its reliability into consideration.

Technical background of the invention and its problems In general, excitation 1tflJ control of a synchronous machine uses excitation control by a variable pressure regulator as the main control, and if the automatic voltage regulator fails, the field current or field of the synchronous machine is A method of continuing operation is by manual adjustment using a constant excitation tttlJn device that controls the magnetic voltage at a constant level.

However, recently, due to the conversion of synchronous light + [Iso's single unit capacity or single-engine city capacity to Oyabin and long-distance power transmission, there are cases where only automatic voltage regulators can be applied from the standpoint of stability. It has become desirable to improve the requirements of excitation control using an automatic voltage regulator, and excitation control devices using a second electric system 71dJ pressure regulator have been adopted.

Figure 1 shows a conventional example of an excitation control device that employs a dual-system automatic ridge adjustment 2k.It shows an instrument transformer 5 that steps down the terminal voltage of a synchronous machine I, an automatic voltage regulator 6, and a reference voltage. The setting device 71- has exactly the same function as 2 ffi'
One of the outputs selected by the changeover switch 8 is manually inputted to the phase control circuit 9, and based on the arc pulse output from the phase control circuit 9, the thyristor exciter 3 outputs the synchronous machine l. An excitation current is supplied to the field winding 2. On the other hand, one side excluded by the changeover switch 8 is in standby operation with an open circuit.

Figure 2 shows a conventional example of an excitation control device that has fully developed the reliability of the excitation side 0I41 device fc that employs the double-thread m/pressure adjuster shown in Figure 1. Excitation control Il
In addition to the l:g position, the position t1 control circuit 9 is duplicated, and the ignition pulse of one side is selected by the changeover switch 8 and applied to the thyristor excitation device 3 to form a control system, and the other side is in standby operation with the circuit open.

In both of the conventional examples shown in Fig. Ii and Fig. 2, if an abnormality occurs in the operating side control system selected by the selector switch 8, the control system is immediately switched to the standby side so that the main engine can continue operating. This is what I did.

However, in the excitation control system, the response speed of the automatic voltage regulator is very slow, so it is difficult to use the system quickly and without worrying about failures on the driving side. It is avoidable to control the synchronous machine incorrectly.
1 power) ivy. In addition, the standby side must have the same failure detection as the driving side, so the standby side needs to have the same fault detection as the driving side. If u fails, make sure not to switch from the operating side to the standby side, etc.
Praise and circuitry are also very complicated.

In this way, although it has been desired to improve the reliability of the conventional excitation control system for synchronous machines using automatic pressure regulators, the dual-system self-pressure regulator has attempted to achieve this. l'RL
In the pressure s'4;
, I was there.

OBJECTS OF THE INVENTION An object of the invention is to provide a highly reliable excitation control device for a synchronous machine, which is constructed to eliminate the above-mentioned drawbacks of the prior art and has a simple groove bottom.

SUMMARY OF THE INVENTION In order to super-acidify this target, the misfire J is equipped with three or more automatic voltage regulators, and each automatic voltage regulator's output (1, >
The excitation control of the synchronous machine is executed based on the average value of ; IF what you did to J2! Let it be j1&.

An example of an embodiment of the invention? lr-An embodiment shown in FIG. 3 will be described. A voltage transformer 5 that steps down the terminal voltage of the synchronous machine 1, a voltage regulator 6, and a voltage setting device 7 are provided, three each, to reduce the voltage at each automatic voltage regulator 6. The output signal is inputted into the average value calculation circuit 10, the output of the average value calculation circuit 10 is inputted into the phase control circuit 9, and the thyristor excitation device is activated based on the firing pulse outputted from the phase control circuit 9. 3 supplies an exciting current to the field winding 2 of the synchronous machine I. The average value calculation circuit 10 is configured to calculate and output the average value of three input signals.

Next, the operation of the excitation control device for a synchronous machine of the present invention configured as described above will be explained. During normal operation, the terminal voltage of the synchronous machine 1 is stepped down by the instrument transformer 5 and inputted to the automatic voltage regulator 6, and the set value V of the reference voltage setter 7 is set. + ■20
rVB. , the output signal vII of the automatic voltage regulator 6 after appropriate compensation and amplification.

It is extracted as vFl + vll.

vll with! Although ``21 + v81'' is not exactly the same value due to slight differences in the characteristics of the reference voltage setting device 7 and automatic voltage regulator 6, it shows a value that is almost close to that of ``21 + v81'', and the average value performance value of 1110. The relationship with the output signal V is v.

="11-V□-vll".

Furthermore, the output characteristics of the automatic voltage regulator 6 have upper and lower limit values corresponding to the output voltage saturation value of the thyristor excitation device 3.
Although Vn r vj+ has a steady-state deviation, it is operated at approximately an intermediate value in the linear region within the above-mentioned limit value.

During normal operation, if a failure occurs in one of the triplicate instrument transformers 5, automatic voltage regulators 6, and standard pressure setting devices 7, the automatic The output signal of the voltage regulator 6 becomes abnormally high or abnormally low, and in the worst case, it goes out of control to the output upper limit or lower limit, but the two systems of automatic voltage regulators 46 that are operating normally will prevent this incorrect output. Since it operates to correct, the influence on synchronization@l is reduced.

This will be explained using a concrete example of the unit method.

Normally, the output 4 voltage of the thyristor excitation system R3 is a positive +ll pressure that is considerably larger than the field ridge required when the synchronous machine I is operating at its rated output, for the purpose of improving the transient stability of the synchronous machine I.
It can output negative d pressure, and it is self-contained! 1! ! The output signal of the IIIL pressure regulator 6 is equal to the output voltage of the thyristor excitation device t3, which corresponds to the output voltage saturation of the thyristor exciter t3.
), output lower limit VL2 (po).

The output signal of each automatic section 1 pressure regulator 6 during normal operation is MiJ
Statement L data',) V,, =V,, =V,, =
Vo(pu) fl (7) One series of the triple automatic voltage regulators 6 fails, and its output signal becomes Vx.
(Change in terminal voltage of synchronization + s i when pt becomes
b weight Ve(pu+) is determined by the following formula.

However, 1 (a - automatic voltage adjustment 2. amplification factor [pUlpu)
e targetf, I M, t, T:, vLl-+6 [p
U], VL1=-3(pUl) Ka=300 (
pu/pu), find ve when the synchronous machine 1 is operating at no-load rated operation and at rated load operation.

(1) During no-load rated operation. Vo=1. o (pυ)
When Vx:= V,, -+ 6 CpU), V
e= o, oos CPU, 1 At this time, normal automatic 1
The output signal of the ward pressure regulator is Vo−KaVe=−1,5(
pU) Vx ” When vLl = 3 (pU) ve==
-o, o o 7(1)U) The output signal of this j temple's secant automatic voltage regulator is Vo-KaVe= 3.0 (
pu) (2) iri During bath load operation 0 ``o'' 2.5
As (pU), vx-1'Ll=+6 (pu) When Ve=0. OQ6 CPU) At this time, the output signal of the automatic voltage regulator that senses pressure v0-KaVe = U, 75 (p
u) When Vx=V, , -3(pu) ``e=-(J,
009 (pu) At this time, the output signal of the normal self-excited positive pressure regulator vo-Ka Ve -5,25 [total R of 903 or more
- The results show that when synchronous machine I is under no-load rating and electric load, even if the output signal of the pressure regulator 6 of the failed automatic series goes out of control to either the upper limit value or the lower limit value, The amount of variation in terminal voltage is less than 1%. FC1 constant automatic IF adjustment M device 6
The output of the issue is within the limit of 1, and it is possible to read 1 consecutive and 16 times 1 wholesale.

In addition, when a fault occurs, the output signal of the normal series may be close to 1 g, so check the ability of the automatic voltage regulator. Failure detection does not particularly affect high speeds, and can be reliably carried out using simple methods such as detecting that an abnormality continues for a certain period of time or more.

Next, l! of the song of the present invention! An example will be explained with reference to FIG.

Components that are the same as those in the embodiment shown in FIG. 3 are designated by the same reference numerals, and their explanation will be omitted. In FIG. 4, in addition to the conventional example shown in FIG.
The other phase control circuit 9 is in standby operation, and if the operation 1100 phase control circuit 9 fails, it is immediately switched to the standby side.

According to the structure shown in FIG. 4, up to the average value calculation circuit 10, the same effect as in the embodiment shown in FIG. J.
< The determination of switching from the operating side to the standby side can be made relatively easily since it is only necessary to detect a failure in the phase control circuit 9.

In the embodiments shown in FIGS. 3 and 4, a case has been described in which three instrument transformers 5, three automatic voltage regulators 6, and three reference screw pressure setting devices 7 are provided, but the present invention is not limited to this. When four or more series are provided, not only the same effect can be obtained, but also the amount of change ve in the terminal voltage of synchronous machine l due to a failure in series l can be expressed by equation (1) as shown in equation (2). It decreases even more than that.

However, as described in detail of the n-series number invention, according to the present invention, three or more instrument transformers, three automatic voltage regulators, and three or more reference voltage setters each are provided, and the average output of each automatic voltage regulator is Since the value is supplied to the next stage, the effect on the synchronous machine is small for abnormal signals of either high or low levels due to a single failure in the stage before the average value calculation, and it is extremely easy to detect failures easily and reliably. A highly reliable excitation control device for a synchronous machine can be obtained.

[Brief explanation of drawings]

1 and 2 are block diagrams showing a conventional excitation control device for a synchronous machine, and FIGS. 3 and 4 are block diagrams showing an embodiment of the excitation control device for a synchronous machine according to the present invention. ]...Synchronous machine 2...Synchronous machine field winding 3
...Thyristor excitation device 4...Excitation transformer 5.
...Instrument transformer 6...Automatic voltage regulator 7...
Reference ゛1 Pressure setting device 8... Selector switch 9... Phase control circuit io... Average value calculation circuit (7317) Representative patent attorney Kensuke Norichika (1 person) Fig. 1 Fig. 3

Claims (2)

[Claims] (1) A control device that outputs a control signal to control the terminal voltage of the synchronous machine to match a predetermined reference voltage setting value, and a phase control device that receives the control signal and converts it into a phase angle of an ignition pulse. An excitation control device for a synchronous machine comprising a control circuit and a thyristor excitation device that supplies an excitation current to a field winding of the synchronous machine based on the ignition pulse of the control circuit,
Three or more of the above-mentioned control devices are provided, and an average value calculation circuit is provided before the above-mentioned phase control circuit, and the average value of each control signal output from the three or more control devices 7J) is inputted to the above-mentioned phase control circuit. An excitation control device for a synchronous machine characterized by: (2) A control 011 that outputs a control signal for controlling the terminal voltage of the synchronous machine to match a predetermined reference voltage setting value.
a phase control circuit that converts the control signal into a phase angle of an ignition pulse using human power; and a thyristor excitation device that supplies excitation current to the field winding of the synchronous machine based on the ignition pulse. In an excitation control device for a synchronous machine consisting of
Providing three or more of the above-mentioned control devices, providing two of the above-mentioned phase control circuits, and providing an average value calculation circuit between them,
The average value of each control signal output from the three or more control devices is input to each of the phase control circuits, and one of the firing pulses is selected and input to the thyristor excitation device. Excitation control device for synchronous machine.