JPH10320043A - Servo driver diagnostic device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To constantly diagnose the soundness of a servo driver card that controls the opening and closing of a governor steam valve of a power plant, and minimize fluctuations in plant load even in the event of a failure. SOLUTION: A valve opening signal is output in accordance with an actual valve opening signal input to a servo driver card 21 to control the opening of a governor steam valve (not shown). At the time of diagnosis, a frequency reference signal 105 having a constant frequency and a constant magnitude is generated from the frequency reference signal generator 22 and is input to the servo driver card 21 as a test signal via the test signal generator 24. The output 102 is a superimposed output of the valve opening command (DC signal) and the output of the alternating current by the test signal 101, the filter 50 passes only the alternating current, the rectifier 61 rectifies the alternating current, and outputs the signal 106. Is higher than the set value of the level detector 26, the judgment result signal 107
Is output, and when this output is present, the control block unit 27 determines that the servo driver card 21 is normal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo driver diagnosis apparatus for diagnosing the soundness of a servo driver for controlling a governor valve opening in a power plant, and a servo driver diagnosis for diagnosing the soundness of the diagnosis apparatus itself. It concerns the device.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a configuration of a main part related to control of a governor steam valve built in a conventional main turbine control panel or the like and a configuration of a servo driver diagnostic device. FIG.
FIG. 3 is a block diagram in the logic CPU. FIG. 9 is a diagram showing input / output characteristics of the servo driver card. Both the actual valve opening and the valve opening command are DC signals. Here, the actual valve opening is a signal that is an actual valve opening derived from a signal related to the valve opening such as a deviation from a load set value or a turbine rotational speed set value.

In FIG. 7, reference numeral 1 denotes a valve controller A, 2
Is a switching device for switching the signals of the valve controllers A and B, and manually disconnecting the signal input, 4, a servo driver card, 4 a governor steam valve,
6 is a logic CPU A system, 7 is a logic CPU B
The system, 8 is a servo loop abnormality detector, and 9 is a display unit.

[0004] Here, the servo driver card 4 receives the actual valve opening signal of one of the upper valve controllers A and B, outputs a valve opening command to the governor steam valve 5, and controls the valve opening. ing.

In FIG. 8, the A system 6 of the logic CPU
The servo driver in the B system 7 has the same operating characteristics as the servo driver card 4, and its output is obtained by calculating the deviation from the valve opening command by an adder.

Next, the operation will be described. (1) Valve controller A1 or valve controller B
The switching device 3 selects one of the actual valve opening signals output from the actual valve opening signal. Here, the actual valve opening manually selected can be separated from the output signal. (2) Upon receiving the actual valve opening signal, the servo driver card 4 outputs a valve opening command (command based on the output characteristics in FIG. 9) to the governor steam valve 5 to control the valve opening.

(3) The A system 6 of the logic CPU and the B system 7 of the logic CPU receive the actual valve opening signal and the valve opening command input to the servo driver card 4 and The same operation is performed, the output is compared with the output (valve opening command) from the servo driver card 4 to the governor steam valve 5, and the deviation is output.

(4) The servo loop abnormality detector 8 detects an abnormality according to the magnitude of the deviation, and displays the detection result on a display unit 9 using a plasma display or the like.

[0009]

The conventional servo driver diagnosis apparatus uses a logic CPU to obtain a servo driver card 4 based on an actual valve opening signal input to a servo driver.
The same calculation as in the above is performed, the calculation result is compared with the valve opening command, and an abnormality is detected from the deviation.

This diagnosis is a diagnosis of S / W using the CPU. The diagnosis based on S / W is a diagnosis in a region where the output voltage of the servo amplifier in the servo driver is not saturated (proportional region). As shown in FIG. 9, the diagnosis in the region where the output of the servo amplifier is saturated is not always abnormal even if the deviation becomes large, so that accurate diagnosis cannot be performed, and there is a problem that the diagnosis is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to accurately diagnose the operation of a servo driver regardless of a proportional region and a saturated region. It is another object of the present invention to minimize the fluctuation of the plant load even if a failure occurs, by always making a diagnosis.

[0012]

[Means for Solving the Problems]

(1) A servo driver diagnostic device according to the present invention is a servo driver diagnostic device that diagnoses a servo driver that controls opening and closing of a governor valve of a power plant. Diagnostic means for determining the presence or absence of an abnormality in accordance with the magnitude of the signal of the alternating current to be performed.

(2) In the above (1), a simulated servo driver having the same characteristics as the servo driver is provided, and a DC bias signal and a predetermined AC test signal are input to the simulated servo driver, and the output thereof is output. Self-diagnosis means for determining the presence or absence of an abnormality in the self-diagnosis device according to the magnitude of the signal of the AC component.

(3) In the above (2), the self-diagnosis means prepares two AC test signals of a low level signal and a high level signal as AC test signals, and inputs the low level signal to the simulation servo driver. When the output of the AC is low, the output is determined to be normal when the output is low, and when the output is high, the output is determined to be abnormal. If the level is low, the means is determined to be normal, and if the level is low, it is determined to be abnormal.

(4) In the above (2), means for switching between diagnosis by the diagnosis means and diagnosis by the self-diagnosis means is provided.

(5) In the above (2), the diagnosis of the servo driver is the first mode diagnosis, the diagnosis of the simulated servo driver using the low level signal is the second mode diagnosis, and the high level signal is used. The diagnosis of the simulated servo driver is performed in the third mode, and means for periodically and repeatedly executing the diagnosis in each of the above modes is provided.

(6) In any one of the above items (1) to (5), a band-pass filter which receives an output signal of a servo driver or a simulated servo driver as an input and passes a frequency of an AC test signal is provided, The presence or absence of an abnormality is determined according to the magnitude of the signal of the alternating current passing through the band pass filter.

(7) In any one of the above items (1) to (6), there is provided means for cutting off the input of the AC test signal to the servo driver.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part relating to control of a governor steam valve and a configuration diagram of a servo driver diagnosis device. FIG.
Is a block diagram showing the configuration of the servo driver diagnostic device,
A / B servo driver diagnostic devices 14 and 15 in FIG.
This is a diagram showing the configuration of FIG.

In FIG. 1, reference numeral 1 denotes a valve controller A, 2
Numeral denotes a valve controller B, 3 denotes a switching device for switching the signals of the valve controllers A and B and manually disconnecting the signal input, and 11 denotes a standby system switching device. The internal configuration is the same as that of the switching device 3. Reference numeral 12 denotes an A-system servo driver card, 13 denotes a B-system servo driver card, 5 denotes a governor steam valve, 14 denotes an A-system servo driver diagnostic device, and 15 denotes a B-system servo driver diagnostic device.

In FIG. 2, reference numeral 21 denotes a servo driver card, which is an A-system / B-system servo driver card 12, 1 shown in FIG.
3, the actual valve opening signal and the AC test signal 101 are input, and the output 102 is a signal obtained by combining the valve opening command and the AC component of the test signal. 22
Is a frequency reference signal generator, which has a predetermined frequency (for example, 1 k
Hz) of a sine wave frequency reference signal 105 of a predetermined magnitude.
Occurs. 23 is a signal stop detection circuit for detecting the stop of the frequency reference signal 105.

Reference numeral 24 denotes a test signal generation unit for generating a test signal 101, which includes an adder and a frequency reference signal 105.
The test signal 101 is generated by adding and subtracting the output signal 102 from the servo driver card 21 and the output signal 104 from the sample hold unit 25.

Reference numeral 25 denotes a sample and hold unit which samples and holds an output signal 102 from the servo driver card 21, and 26 denotes a level detector.
Of the output signal 102 from the filter 50, the AC component is extracted by the filter 50, and the DC component is rectified by the rectifier 61, and the signal of the DC component is compared with a predetermined preset value. The judgment result signal 107 is transmitted. Reference numeral 27 denotes a control logic unit for controlling the entire diagnostic apparatus.

Next, the operation will be described. In FIG. 1, the output from the valve controller A or the valve controller B is always input to the A-system servo driver card 12 using the switching device 3, and the governor steam valve 5 is opened and closed by the valve opening command which is the output. . If there is an abnormality in the A-system servo driver card 12, the governor steam valve 5 is opened and closed using the standby system switching device 11 and the B-system servo driver card 13.

The A-system servo driver diagnostic device 14 diagnoses the always-used A-system servo driver card 12, and the B-system servo driver diagnostic device 15 diagnoses the standby B-system servo driver card 13. The contents of this diagnosis will be described with reference to FIG.

In FIG. 2, the frequency reference signal generator 22
Generates a frequency reference signal 105. The frequency reference signal 105 is a sine wave signal of a predetermined frequency and a predetermined magnitude, that is, an AC signal. In this case, the magnitude of the signal is a high-level AC signal at which a level detection unit 26 described later sends out a detection output. Signal.

The sample and hold unit 25 samples and holds the output from the servo driver card 21, and the sampled and held output 104 becomes the addition input of the adder of the test signal generation unit 24. On the other hand, the output 102 of the servo driver card 21 becomes a subtraction input of the adder of the test signal generator 24 as a feedback signal. Therefore, the servo driver card 21 and the test signal generator 24 form a closed loop.

In the adder of the test signal generator 24, the output signal 102 of the servo driver card and the output signal 104 of the sample-and-hold unit 25 are canceled and the frequency reference signal 1
05 is output as the test signal 101. The servo driver card 21 outputs the test signal 10 together with the actual valve opening signal.
1 is input and the output signal 102 of the servo driver card is
Is output with the AC component of the test signal 101 superimposed together with the valve opening command (DC signal).

At this time, the input test signal 101 does not respond to the servo steam valve 5 which is a load of the servo driver card 21, but the internal circuit of the servo driver card 21 has a frequency which can respond.

Therefore, the servo driver card 21 responds to the frequency of the test signal 101 regardless of whether it is operating in the non-saturation area (proportional area) or the saturation area. The output is obtained.

Therefore, the output 102 of the servo driver card 21 is controlled by the closed loop control so that the output 102 of the high-level test signal 101 of the high-level test signal 101 is transmitted to the valve opening command unless there is a failure such as the fixation of circuit components inside the servo driver card 21. The waveform is a superimposed waveform.

Next, the determination operation based on the output signal 102 of the servo driver card 21 will be described. Of the output signal 102 of the servo driver card 21, the valve opening command, which is a DC component, is cut by the filter 50, and only the AC component passes. This AC component is full-wave rectified by the rectifier 61 and input to the level detector 26 as a DC detection waveform component 106. The level detector 26 compares it with a predetermined set value and outputs a determination result signal 107 if it is equal to or more than the set value.

If the frequency reference signal 105 of the frequency reference signal generator 22 is a high-level signal, the control logic unit 27 outputs a determination result signal 107, and determines that the servo driver card 21 is normal. The servo driver abnormality alarm 108 is not output. If the frequency reference signal 105 is a high level signal and the determination result signal 107 is not output, the servo driver card 21 is determined to be abnormal, and the servo driver abnormality alarm 108 is output.

As described above, the governor steam valve 5 serving as a load
, And the soundness of the servo driver card 21 can be constantly diagnosed.

Embodiment 2 In the first embodiment, only the servo driver card 21 is diagnosed. However, in the second embodiment, a simulated servo driver unit and a changeover switch are provided inside the servo driver diagnostic device, so that the servo driver diagnostic device itself can be diagnosed. It enables self-diagnosis and improves the safety of diagnosis.

FIG. 3 shows an embodiment of the present invention provided with a simulated servo driver and a changeover switch. Reference numeral 41 denotes a simulation servo driver unit, which includes a bias signal generation unit that simulates a saturation signal, an adder that adds a bias signal and a test signal, and a servo driver card 21 that inputs the addition result and inputs the result.
Calculate and output with the servo drive whose operating characteristics are the same.

Reference numerals 42, 43, 44 and 45 denote switches for switching between a closed loop of the simulated servo driver unit and the servo driver card. The switches are controlled by the control block unit 27, and the switches 42 and 45 are ON and the switches 43 and 44 are OFF.
In the case of (1), the servo driver card 21 is diagnosed, the switches 42 and 45 are turned off, and in the case of the switches 43 and 44, the simulated servo driver unit 41 is diagnosed to diagnose the servo driver diagnostic device itself.

Next, the operation of the second embodiment will be described. In the self-diagnosis of the servo driver diagnostic device using the simulated servo driver unit 41, a predetermined low-level sine wave signal at a predetermined frequency is used as the frequency reference signal 105 from the frequency reference signal generation unit 22, and this is used as a test signal. Is input to the simulated servo driver unit 41, and the signal 203 of the determination result is not detected and confirmed, thereby determining that the signal is normal.

Also, a high-level sine wave signal at a predetermined frequency is used as the frequency reference signal 105, and the sine wave signal is input to the simulated servo driver 41 as a test signal, and the signal 203 of the determination result is detected and confirmed. Judge as normal. Diagnosis is performed by using the test signals having the two different levels.

First, a low-level test signal 2 of a predetermined frequency
The operation of confirming non-detection by inputting 01 to the simulated servo driver unit 41 will be described. Switch 42, switch 4
5 = OFF, switch 43, switch 44 = ON, simulation servo driver 41 and test signal generator 24
Form a closed loop as shown in FIG.

The test signal 201 of the closed loop is a difference between the sum of the output signal 104 of the sample hold unit 25 and the frequency reference signal 105 of the frequency reference signal generation unit 22 and the output signal 202 of the simulated servo driver 41 as a feedback signal. It is. The simulation servo driver 41
Applies the bias input (saturation signal) and outputs the output signal 20
2 is brought into a saturated state (+ potential).

The sample hold section 25 samples and holds the output signal 202 of the simulation servo driver section 41,
The voltage output 104 is input to the adder of the test signal generator 24. Then, in the adder, the output 104 and the output signal 202 of the simulation servo driver 41 are canceled, and as a result, the frequency reference signal 105 is changed to the low level test signal 2.
01 and input to the simulation servo driver 41.

By the control of the closed loop, the output 202 of the simulation servo driver 41 has a waveform in which a predetermined frequency of the saturation signal by the bias signal and the low level test signal 201 are superimposed. This output 202 is input to the level detector by the rectifier 61 as the detected waveform component 106 after the AC component is extracted by the filter 50. The detected waveform component 10
Since 6 is low level, it becomes less than the set value of the level detector 26, the self-diagnosis abnormal signal 203 is not output, and the operation of the diagnostic device itself is determined to be normal.

If the DC wave formation 106 is equal to or greater than the set value despite the fact that the low-level frequency reference signal 105 is being generated from the frequency reference signal generator 22, the level detector 26 outputs the self-diagnosis abnormality signal 203. , And the control logic unit 27 outputs a self-diagnosis failure alarm 204.

Next, a high-level test signal 3 having a predetermined frequency
The diagnostic operation when 01 is input to the simulated servo driver 41 will be described. As shown in FIG. 3, the simulated servo driver 41 is used to confirm the detection of a sine wave signal having a predetermined frequency.

Switches 42 and 45 = OFF, switch 4
When 3,44 = ON, the simulated servo driver 41 and the test signal generator 24 form a closed loop as shown in FIG. The frequency reference signal generator 22 generates a high-level frequency reference signal 105, and outputs the high-level frequency reference signal 1
A high-level test signal 301 corresponding to “05” is generated.
Here, the sample hold unit 25 and the test signal generation unit 24
Is the same operation as the case of the low-level frequency reference signal, and the description is omitted.

When the high-level test signal 301 is input to the simulated servo driver 41, the output signal 302 is a signal obtained by superimposing the DC saturation signal by the bias signal of the simulated servo driver 41 and the high-level test signal 301. . The output signal 302 has its AC component extracted by the filter 50, full-wave rectified by the rectifier 61, and subjected to the detection waveform component 10.
6 is input to the level detector 26. The level detector 26 detects that the detected waveform component 106 is equal to or greater than the set value.
It is determined that the diagnostic device itself is normal, and the self-diagnosis abnormality signal 203 is not output.

In this way, the diagnostic device itself can be diagnosed. The bias signal of the simulated servo driver unit 41 was tested such that the output of the servo driver was saturated. However, the test can be performed in a non-saturated region (proportional region).

Further, by turning off the switches 43 and 44 and turning on the switches 42 and 45, the servo driver card 21 can be diagnosed at any time. Further, the switches 43 and 44 and the switches 42 and 45 may be alternately switched to periodically perform the diagnosis of the servo driver card 21 and the self-diagnosis device.

Embodiment 3 FIG. 4 is a configuration diagram of this embodiment. In the figure, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 51 denotes a band-pass filter that passes the frequency of an AC signal that is a frequency reference signal.

The band-pass filter 51 not only cuts the direct current component, but also can reduce the intrusion of noise, and can make the judgment operation of the level detector 26 accurate. Therefore, the diagnosis can be performed irrespective of the environment of the servo drive card or the diagnosis device to be diagnosed.

Embodiment 4 FIG. FIG. 5 is a time chart showing the relationship between the test periods of this embodiment. The configuration of this embodiment is the same as that of the second or third embodiment, and will be described with reference to FIG. 3 of the second embodiment.

In FIG. 3, the control block 27 operates the switches 42, 43, 44 and 45 to ON and OFF,
As shown in FIG. 5, a test using the low-level test signal of the simulated servo driver unit 41, a test using the high-level test signal of the simulated servo driver unit 41, and a test using the high-level test signal of the actual servo driver card 21 are performed. Diagnosis is executed while controlling the governor steam valve 5 at all times by repeating it sequentially and periodically.

As described above, the diagnosis according to this embodiment can be performed without interrupting the operation during the operation of the power plant. Further, not only the diagnosis of the servo driver card 21 but also the self-diagnosis of the diagnosis device is performed. Can also be performed at the same time.

Embodiment 5 FIG. 6 shows a configuration diagram of this embodiment. In the figure, a switch 82 is turned on and off by a manual switch 81, and the switch 82 is turned off.
By setting F, the test signal to the servo driver card 21 is turned off, and the servo driver card 21 and the servo driver diagnostic device can be functionally separated. Further, by generating the diagnosis stop command 401, the servo driver diagnosis device itself can be stopped. By the above separation, maintenance of the diagnostic device itself can be executed,
In addition, it is possible to eliminate the influence on the plant due to a malfunction or a malfunction of the diagnostic device.

Embodiment 6 FIG. In the above embodiment, the diagnosis of the servo driver card that controls the governor steam valve used in the thermal / nuclear power plant has been described. However, the present invention can be applied to the governor valve of the hydroelectric power generation. Further, the servo driver card is not limited to a card, and can be applied to a card having a servo driver function such as a servo driver circuit. In the first embodiment, the diagnosis is performed by inputting an AC test signal to the servo driver during plant operation, but the servo driver may be diagnosed during non-operation. In this case, a test signal in which an AC signal and a DC bias signal are superimposed may be used.

[0057]

【The invention's effect】

(1) As described above, according to the present invention, since the servo driver is diagnosed using the AC test signal, the diagnosis can be performed even during the operation of the plant.

(2) Since the diagnosis is performed using the simulated servo driver, the diagnosis of the diagnosis device itself can be performed.

(3) Since the diagnosis of the servo driver and the diagnosis of the diagnostic device itself are switched and executed, both diagnoses can be made and a reliable diagnosis can be made.

(4) Since the diagnosis of the servo driver and the diagnosis of the diagnosis device itself are periodically and repeatedly executed, reliable diagnosis can be performed.

(5) Since noise is removed by the band-pass filter, erroneous diagnosis can be prevented.

(6) Since the diagnostic device is functionally separated from the plant, maintenance and the like of the diagnostic device itself can be executed by this separation, and the malfunction of the diagnostic device and the influence on the plant due to erroneous operation can be reduced. Can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a main part related to control of a governor steam valve and a configuration of a servo driver diagnostic device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a servo driver diagnosis device according to Embodiment 1 of the present invention;

FIG. 3 is a configuration diagram of a servo driver diagnosis device according to Embodiment 2 of the present invention;

FIG. 4 is a configuration diagram of a servo driver diagnosis device according to Embodiment 3 of the present invention.

FIG. 5 is a timing chart of a test period according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a servo driver diagnosis device according to Embodiment 5 of the present invention.

FIG. 7 is a block diagram showing a configuration of a main part related to control of a conventional governor steam valve and a configuration of a servo driver diagnostic device.

8 is an internal configuration diagram of the logic CPU of FIG. 7;

FIG. 9 is a diagram showing input / output characteristics of a servo driver card.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Valve controller A 2 Valve controller B 3 Switching device 5 Governor steam valve 11 Standby switching device 12 A system servo driver card 13 B system servo driver card 14 A system servo driver diagnostic device 15 B system servo driver diagnostic device 21 servo Driver card 22 Frequency reference signal generation unit 23 Signal stop detection circuit 24 Test signal generation unit 25 Sample hold unit 26 Level detection unit 27 Control logic unit 41 Simulated servo driver units 42, 43,
44, 45 switch 50 filter 51 band pass filter 61 rectifier 81 manual switch 82 switch 101 test signal 102 servo driver card output signal 104 sample hold output signal 105 frequency reference signal 106 detected waveform component 107 judgment result signal 108 servo driver abnormality alarm 201 low Level test signal 202 Simulated servo driver output 203 Self-diagnosis abnormal signal 204 Self-diagnosis failure alarm 301 High-level test signal 401 Diagnosis stop command

Claims (7)

[Claims] 1. A servo driver diagnostic apparatus for diagnosing a servo driver that controls the opening and closing of a governor valve of a power plant, wherein a predetermined AC test signal is input to the servo driver, and a magnitude of an output AC signal is output. A servo driver diagnostic device, comprising: diagnostic means for determining the presence / absence of an abnormality according to the condition. 2. The servo driver diagnostic apparatus according to claim 1, further comprising: a simulated servo driver having characteristics equivalent to those of the servo driver, wherein a predetermined DC bias signal and a predetermined AC test signal are input to the simulated servo driver. And a self-diagnosis means for judging the presence or absence of an abnormality in the self-diagnosis device according to the magnitude of a signal of the output AC. 3. The servo driver diagnosis apparatus according to claim 2, wherein the self-diagnosis means prepares two AC test signals of a low level signal and a high level signal as the AC test signal,
When the low-level signal is input to the simulated servo driver, the output is determined to be normal when the output of the AC is low, and abnormal when the output is high, and when the high-level signal is input to the simulated servo driver. A servo driver diagnosis device for determining that the output of the alternating current is high when the output is high and that the output is abnormal when the output is low. 4. The servo driver diagnosis apparatus according to claim 2, further comprising means for switching between diagnosis by the diagnosis means and diagnosis by the self-diagnosis means. 5. The servo driver diagnosis apparatus according to claim 2, wherein the diagnosis of the servo driver is a first mode diagnosis.
Diagnosis of simulated servo driver using low-level signal
A servo driver diagnosis apparatus, wherein a diagnosis of a simulated servo driver using a high-level signal is performed as a third mode diagnosis, and a means for periodically and repeatedly performing the diagnosis in each mode is provided. 6. The servo driver diagnostic apparatus according to claim 1, further comprising a band-pass filter that receives an output signal of the servo driver or the simulated servo driver as an input and passes a frequency of an AC test signal. A servo driver diagnostic device, wherein the presence or absence of an abnormality is determined according to the magnitude of a signal of an alternating current passing through a band-pass filter. 7. The servo driver diagnosis apparatus according to claim 1, further comprising means for cutting off the input of an AC test signal to the servo driver.