JPH02262900A - Excitation controller - Google Patents

Abstract

PURPOSE:To improve reliability by providing an automatic voltage regulator which outputs a phase control command signal, a phase comparator for forming an ignition command signal, intermediate signal selecting means for selecting an ignition command signal, a pulse generator for generating an ignition pulse, and a rectifier for rectifying an exciting power source voltage to apply it to a field winding. CONSTITUTION:An output voltage is converted by an exciting power source voltage Wa, which is applied to a thyristor rectifier 13 and exciting controllers 60-80. Automatic voltage regulators 62-82 detect a voltage reference signal VF, a deviation of voltage detection signals VV1-VV3, phase control command signals VC1-VC3 are formed, and phase comparators 63-83 compare phase signals HP1-HP3 with the phase control command signals VC1-VC3 to form ignition command pulse signals PC1-PC3. Intermediate pulse selectors 65-85 form ignition command pulse signals PD1-PD3, and pulse generators 66-86 generate ignition pulses PE1-PE3. A thyristor rectifier 13 rectifies an exciting power source voltage Va, and applies a DC voltage to a field winding 14.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a highly reliable excitation control device for a synchronous machine.

(Prior Art) One method of improving the reliability of an excitation control device that excites a synchronous machine is to duplicate the excitation control device.

In this method, one of the two excitation control devices is set as the regular system and the other is set as the standby system, and during normal operation, excitation control is performed using the regular system, and if a failure occurs in the regular system, In this case, control is switched to the standby system, and a conventional example thereof is shown in FIG.

The output voltage of the synchronous machine 1 is converted into a predetermined excitation power supply Vac+ by an excitation transformer 2 and applied to a thyristor rectifier 3, as well as to a regular excitation control device 4 and a standby excitation control device 5.

, in the regular system excitation control device 4 and the standby system excitation control device 5, the voltage detectors 41.51 detect the output voltage of the synchronous machine 1, and the voltage detection signals VGI, VG
2 are output to automatic voltage regulators 42 and 52, respectively.

The automatic voltage regulator 42.52 detects a deviation between the voltage reference signal VR and the voltage detection signals VGI, VG2, and forms phase control command signals VAI, VA2 corresponding to the deviation,
The phase control command signals VAI and VA2 are output to phase comparators 43 and 53, respectively.

The voltage phase detectors 44.54 detect phase signals P)11. corresponding to the phase of the excitation power supply Vac. PH2 and its phase signals P)+t, P)12 are sent to a phase comparator 43.5, respectively.
Output to 3.

The phase comparators 43.53 compare the phase signals PHI, PH2 and the phase control command signals VAI, VA2, respectively, so that the phase signals P)II, PH2 correspond to the phase control command signals VAI, V
Ignition command pulse signal PAL at timing consistent with A2
, PA2, whose ignition command pulse signals PA 1 and PA2 are output to pulse generators 45 and 55, respectively.

The pulse generator 45.55 generates an ignition command pulse signal PAL.
.

When PA2 is input, the predetermined ignition pulses PBI, PB2
The ignition pulses PBI and PB2 are
They are respectively applied to two switching input terminals 6a and 6b of the switching device 6.

The failure detector 7 detects the occurrence of an abnormality in the regular system excitation control device 4 by determining a missing ignition pulse PBI or an abnormality in calculation of the automatic voltage regulator 42, and is always on. The switch 6 selects the switching input end 6a, and when an abnormality is detected, the switch 6 is switched to the switching input end 6b.

The output signal from the common connection end 6C of the switch 6 is output to the thyristor rectifier 3 as a firing pulse signal PP.

The thyristor rectifier 3 rectifies the excitation power supply Vac in response to the ignition pulse signal PP, thereby exciting and driving the field winding 8 of the synchronous machine 1.

With the above configuration, when the normal system excitation control device 4 is operating normally, the failure detector 7 is set to 1. The switching input end 6a is selected by the switch 6, so that the ignition pulse signal PBI outputted from the normal system excitation control device 4 is applied to the thyristor rectifier 8 as the ignition pulse signal PP.

In this state, when the fault detector 7 detects that an abnormality has occurred in the regular system excitation control device 4, the fault detector 7
is switched to the switching input terminal 6b side, whereby the firing pulse signal PB2 output from the standby system excitation control device 5 is applied to the thyristor rectifier 8 as the firing pulse signal PP.

In this way, when a duplicated excitation control device is used, if an abnormality occurs in the regular excitation control device 4, the regular excitation control device 4 is disconnected from the system and switched to the standby excitation control device 5. Therefore, the synchronous machine I can be operated continuously.

Note that FIG. 7 shows one phase. For example, if the power supply has three phases, the regular excitation control device 4 and the standby excitation control device 5 are provided for three phases, respectively. A phase-corresponding firing pulse signal is formed and a corresponding firing pulse signal is applied to the rectifier arm of the thyristor rectifier 3 corresponding to the respective phase.

(Problems to be Solved by the Invention) However, such conventional devices have the following problems.

■When a failure that cannot be detected by the failure detector 7 occurs, the switching from the regular excitation control device 4 to the standby excitation control device 5 is not performed, and the defective regular excitation control device 4 continues. This may cause the synchronous machine I to operate abnormally.

■Since it takes time to switch from the regular system excitation control device 4 to the standby system excitation control device 5, there is a period from when an abnormality occurs in the regular system excitation control device 4 until control by the standby system excitation control device 5 starts. A control delay occurs during this period.

(2) Since the switching device 6 and the thyristor rectifier 3 are not multiplexed, if an abnormality occurs in these elements, the synchronous machine 1 cannot be appropriately controlled in excitation.

The present invention aims to solve the problems of such conventional devices and provide a more reliable excitation control device.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides at least three automatic voltage regulators that output phase control command signals corresponding to the deviation between the output voltage of the synchronous machine and the set voltage; At least three phase comparators that form a firing command signal based on the phase of the excitation power source and the phase control command signal output from each automatic voltage regulator, and firing command signals output from these phase comparators. At least three intermediate signal selection means for selecting a firing command signal with an intermediate output timing among the intermediate signal selection means, and at least three intermediate signal selection means for generating a firing pulse corresponding to the intermediate firing command signal outputted from each intermediate signal selection means. It is equipped with a pulse generator and a rectifier that rectifies the excitation power source by a combination of the ignition pulses when at least two ignition pulses are generated and applies the same to the field winding of the synchronous machine.

(Function) Therefore, if at least two of the three or more systems are normal, the synchronous machine can be appropriately excited, and the reliability of excitation control is greatly improved.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an excitation control device according to an embodiment of the present invention.

The output voltage of the synchronous machine 11 is converted into a predetermined excitation power source Va by the excitation transformer 12 and applied to the thyristor rectifier 13, and the three excitation control devices 60°, 70.8
added to 0.

In the excitation control devices 60, 70, 80, the voltage detector 6
1°71.81 detects the output voltage of the synchronous machine I, and its voltage detection signals VVI, VV2. VV3 is output to automatic voltage regulators 62, 72, and 82, respectively.

The automatic voltage regulators 62, 72, 82 receive a voltage reference signal V
F and voltage detection signals VVI, VV2. Detects the deviation of VV3 and generates phase control command signals VCI, V corresponding to the deviation.
C2 and VC3, and the phase control command signal VCI,
VC2 and VC3 are connected to phase comparators 63 and 73.83, respectively.
Output to.

The voltage phase detectors 64, 74, 84 are connected to the excitation power source Va.
Phase signals HPI, HP2 . HP3 and a phase reference signal HSI corresponding to the phase reference timing of the excitation power supply Va, )ls2. H53 and phase signals HPi, )HF2. HF2 is output to the phase comparators 63, 73.83, respectively, and the phase reference signals H5I, H52, H53 are output to the intermediate pulse selection circuit 65.
, 75.85.

The phase comparators 63, 73.83 output phase signals HPI, HP
2. HP3 and phase control command signals VCI, VC2, VC3
are compared, and the phase signals HPI, HP2 . HP3
At the timing when the phase control command signals VC1, VC2, VC3 match, the ignition command pulse signals Pct, PC2, PO
2, and its ignition command pulse signal PC
I, PC2, and PO2 are output to intermediate pulse selection circuits 65, 75, and 85, respectively.

The intermediate pulse selection circuits 65, 75.85 select the ignition command pulse signal PCI, PC which is generated second among the three applied ignition command pulse signals PCI, PC2, PO2.
2. Select PO2 and select the selected ignition command pulse signal PCI.

Ignition command pulse signals PDI, PD2 .corresponding to the generation timing of PO2, PO2. PO2, and its ignition command pulse signals PDI, PD2. PO2 is output to pulse generators 66, 76, and 86, respectively.

The pulse generators 66, 76, 86 generate ignition command pulse signals PDI, PD2 . When PO2 is input, the predetermined ignition pulse PHI.

PH2, PH3, and their ignition pulses PHI, PE2. PE3 is the thyristor rectifier 13
has been added to.

The thyristor rectifier 13 receives the ignition pulse signals PEI, PH.
2. When Pfi3 is input, its rectifier arm fires depending on the combination of these inputs, thereby rectifying the excitation power source Va and applying a DC current to the field winding 14.

Here, FIG. 1 only shows one phase of the power supply, and when the power supply consists of three phases, U phase, ■ phase, and V phase, each excitation control device 60, 70, 80 is 3
A system processing system is provided, and ignition pulse signals PH1, PH
2, PH3 are formed for each phase.

Below, the components of each phase of the firing pulse signals PHI, PH2, PE3 are converted into firing pulse signals PIE1u, PH1v,
PE1w, PH2u.

PH2v, PE2w, PH3u, PH3v
, called PE3w.

FIG. 2 shows an example of the intermediate pulse selection circuit 65. Note that the intermediate pulse selection circuits 75 and 85 also have the same configuration as the intermediate pulse selection circuit 65.

Firing command pulse signals Pct, PC2, PO2 are sent to flip-flops FFI, FF2 . It is added to the input terminal J of FF3.

The signal at the output terminal Q of the flip-flop FFI at J- is applied to one input terminal of the AND circuit ADI and the AND circuit AD2, and the signal at the output terminal Q of the flip-flop FF2 at J- is applied to the input terminal of the AND circuit ADI and one of the AND circuits AD2. is added to the other input terminal and one input terminal of the AND circuit AD3,
The signal at the output terminal Q of the flip-flop FF3 is applied to the other input terminals of the AND circuit AD2 and the AND circuit AD3.

AND circuit ADI, AD2. The output signal of AD3 is applied to the input terminal of the OR circuit OR, and the output signal of the OR circuit OR is output to the next stage circuit as the ignition command pulse signal PDI, and is also applied to the flip-flops FFl, J-.
FF2. It is added to the input terminal K of FF3.

In addition, flip-flops FFI, FF2. FF3
A 1-phase reference signal H5I is applied to the clear input terminal CR of.

Therefore, when the phase reference signal H81 is output at the phase reference timing of the excitation power supply Va, the flip-flops FFI, FF2 . After all FF3 are cleared, ignition command pulse signals Pct, PC2, and PO2 are sequentially output from the phase comparators 63, 73, and 83 with variations.

At this time, as shown in FIGS. 3(a) to (k), no matter what order the ignition command pulse signals Pct, PC2, and PO2 are output, the second ignition command pulse signal is output. At the specified timing, one of the AND circuits ADI
, AD2. The output of AD3 rises to the logic H level, thereby causing the 1-ignition command pulse signal PDI to rise.

At the rising timing of this ignition command pulse signal PDI,
Flip-flops FFI, FF2. Since FF3 is reset, flip-flops FFI and FF are connected to J-.
2. FF3, AND circuit AD1. AD2. When the gate delay time of AD3 and the OR circuit OR has elapsed, the ignition command pulse signal PDI falls.

In this manner, the intermediate pulse selection circuit 65 generates the ignition command pulse signal PCI in synchronization with the generation timing of the second one of the ignition command pulse signals Pct, PC2, and PO2.

That is, the intermediate pulse selection circuit 65 can output the ignition command pulse signal PD1 if at least two of the ignition command pulse signals Pct, PC2, and PO2 are output normally, and therefore the voltage detection vessel 61,7
Even if an abnormality occurs in one of the three systems from 1, 81 to phase comparators 63, 73, 83,
An appropriate ignition command pulse signal PD1 can be output.

FIG. 4 shows an example of the thyristor rectifier 13.

This thyristor rectifier 13 has six rectifier arms AM
It has a configuration in which u, AMv, AMw, AMx, AMv, and AMz are connected to a three-phase pure bridge.

Further, as shown in FIG. 5, the rectifier arm AMu includes thyristors SL, S2, thyristors S3, . S4, and thyristor S5. S6 are connected in series, the firing pulse signal PE1u is applied to the gates of thyristor St and thyristor S6, and the firing pulse signal PH2υ is applied to the gates of thyristor S2 and thyristor S3.
The firing pulse signal PH30 is applied to the gates of thyristors S4 and S5.

Therefore, three ignition pulse signals PE1u, PH2u
, PE3υ, if any two of them are applied simultaneously, the rectifier arm AMu becomes conductive.

That is, the rectifier arm AMυ receives any two of the three ignition pulse signals PHIυ, PH2υ, and PE3u.
If any one of the ignition pulse signals is output normally, conduction can be established, and therefore, even if any one of the ignition pulse signals is missing, normal operation can be performed.

With the above configuration, three excitation control bags j160, 70.80
are operating normally, the ignition pulse signals PEI, PE are sent from the respective excitation control devices 60, 70, 80.
2. PH3 is outputted accordingly, whereby the rectifier arms AMu, AMv, of the thyristor rectifier 13
AMw, AMx, AMy, and AMZ are made conductive at the timing of their corresponding phases, and a drive current is supplied to the field winding 14 of the synchronous machine I, so that the synchronous machine I is controlled to match the target voltage. .

For example, if an abnormality occurs in the automatic voltage regulator 62 of the excitation control device 60 and the output of the one-phase control command signal VC1 becomes abnormal, the ignition command pulse signal PCI output from the phase comparator 63 The output timing becomes abnormal.

In this case, the intermediate pulse selection circuits 65, 75.85 select the ignition command pulse signals PC2, PC3, as described above.
Based on the output timing of ignition command pulse signal PD
I, PD2. PO2, whereby the pulse generator 66.76.86 appropriately outputs the ignition pulse signal P
Since H1°PH2 and PH3 are output, excitation control of the synchronous machine 1 is performed appropriately.

For example, if an abnormality occurs in the intermediate pulse selection circuit 75 and the ignition command pulse signal PD2 is no longer output,
The ignition pulse signal PE2 is no longer output from the pulse generator 76.

In this case, since the ignition pulse signals PHI and PH3 are output, the rectifier arm AMu of the thyristor rectifier 13
, AMv, AMw, AMx, AMv, and AMx are made conductive at the timing of their corresponding phases, thereby making it possible to appropriately control the excitation of the synchronous machine 1.

As described above, in this embodiment, three excitation control devices 60
,70.Even if an abnormality occurs in one of 80,
Since the excitation of the synchronous machine 1 can be appropriately controlled, the reliability of the excitation control is greatly improved.

Further, the intermediate pulse selection circuits 65, 75, 85 absorb variations in the output timing of the ignition command pulse signals Pct, PC2, PC3, and furthermore, the rectifier arms AMu, AMv, AMw, ^Mx, AMv,
AMz absorbs variations in the output timing of the ignition pulse signals PHI, PH2, and PE3, so synchronous machine 1
excitation control can be performed more accurately.

Also, in order to inspect one of the excitation control devices 60, 70, 80, it can be separated from the control system.
The maintainability of the excitation control device is also improved.

By the way, in the embodiment described above, three systems of excitation control devices are provided, but four or more systems may also be provided.

For example, four systems of excitation control devices may be provided, each receiving ignition pulse signals PFI, PF2, . PF3. When PH4 is output, the rectifier arm of the thyristor rectifier is configured as shown in FIG.

This rectifier arm consists of three thyristors S connected in parallel.
S1. SS2. SS3, thyristor SS4. SS5. S
S6, thyristor SS7. SS8. SS9 and thyristor 5SIO.

It has a configuration in which 5SII and 5S12 are connected in series, and the firing pulse signal PFI is transmitted by thyristors SSI, SS9, and 5S11.
The ignition pulse signal PF2 is applied to the thyristor SS
2, SS4, SS12, and the firing pulse signal PF3 is applied to the thyristor SS3. SS5. The one firing pulse signal PF4 applied to SS7 is applied to thyristor SS6. S
It has been added to S8,5SIO.

This rectifier arm therefore receives the firing pulse signal PF
I, PF2. PF3. Since conduction occurs if at least two of the PH4s are output, excitation control can be performed appropriately even if an abnormality occurs in up to two of the four excitation control devices.

[Effects of the Invention] As described above, according to the present invention, three or more systems of excitation control devices are provided, and an ignition command pulse signal having an intermediate output timing is selected from among the ignition command pulse signals of each system. Since the ignition pulse signal is formed and the drive current is supplied to the excitation winding while at least two of these ignition pulse signals are being output, two of the three control systems If the above is in normal operation, the synchronous machine can be excitation controlled, and an extremely reliable excitation control device can be realized.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an excitation control device according to an embodiment of the present invention, Fig. 2 is a block diagram showing an example of an intermediate pulse selection circuit, and Fig. 3 explains the operation of the circuit in Fig. 2. 4 is a block diagram showing a configuration example of a thyristor rectifier, FIG. 5 is a circuit diagram showing a configuration example of a rectifier arm, and FIG. 6 is a configuration of a rectifier arm according to another embodiment of the present invention. FIG. 7 is a block diagram illustrating a conventional device. 13... Thyristor rectifier, 61, 71, 81...
Voltage detector, 62.72.82... Automatic voltage regulator, 63, 73.83... Phase comparator, 64, 74
, 84... power supply phase detector, 65, 75.85...
Intermediate pulse selection circuit, 66.76.86...Pulse generator, AMu, AMv, AMw, AMx, AMv, AM
z-rectifier arm, 5L-86, SS1~5S12...
・Thyristor. (7317) Agent, patent attorney, close aide Kensuke (88)
69) The same Daishimaru Ken's drawing diagram diagram diagram diagram diagram diagram

Claims (1)

[Claims] at least three automatic voltage regulators that output phase control command signals corresponding to the deviation between the output voltage of the synchronous machine and the set voltage; and the phase of the excitation power source of the synchronous machine and the phase output from each automatic voltage regulator. At least three phase comparators that form a firing command signal based on a control command signal, and at least three that select a firing command signal with an intermediate output timing from among the firing command signals output from these phase comparators. at least three pulse generators that generate firing pulses corresponding to the intermediate firing command signals outputted from the respective intermediate signal selection means, and at least two pulse generators that generate at least two firing pulses; An excitation control device comprising a rectifier that rectifies the excitation power source by a combination of these ignition pulses and applies the same to the field winding of the synchronous machine when the synchronous machine is in use.