JP3420022B2 - Servo driver diagnostic device - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a configuration of a main part relating to control of a governor steam valve incorporated in a conventional main turbine control panel and the configuration of a servo driver diagnostic device. Figure 8
[Fig. 3] is a block diagram in the logic CPU. FIG. 9 is a diagram showing the input / output characteristics of the servo driver card, in which both the actual valve opening and the valve opening command are DC signals. Here, the actual valve opening degree is a signal that is an actual valve opening degree derived from a signal related to the valve opening degree such as a deviation from a load setting value or a turbine rotation speed setting value.

In FIG. 7, 1 is a valve controller A, 2
Is a valve controller B, 3 is a switching device that switches the signals of the valve controllers A and B, and manually disconnects the signal input, 4 is a servo driver card, 5 is a governor steam valve,
6 is A system of logic CPU, 7 is B of logic CPU
A system, 8 is a servo loop abnormality detector, and 9 is a display unit.

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 the output of the servo driver is the deviation from the valve opening command, which is obtained by the 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 from the actual valve opening signal output from the control device 2. Here, the actual valve opening selected manually can be separated from the output signal. (2) In response to this actual valve opening signal, the servo driver card 4 outputs a valve opening command to the governor steam valve 5 (command according to the output characteristic of FIG. 9) 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 as inputs, and store them in the servo driver card 4. The same calculation is performed, the output from the servo driver card 4 to the governor steam valve 5 (valve opening command) is compared, 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 the display unit 9 using a plasma display or the like.

[0009]

The conventional servo driver diagnostic device uses the logic CPU to output the actual valve opening signal input to the servo driver so that the servo driver card 4 can be operated.
The same calculation as in the above is performed, the calculation result is compared with the valve opening command, and the abnormality is detected from the deviation.

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

The present invention has been made to solve the above problems, and an object of the present invention is to accurately diagnose a servo driver regardless of whether it is in a proportional region or a saturated region. In addition, it is an object to minimize plant load fluctuations in the unlikely event that a failure occurs by constantly diagnosing.

[0012]

(1) A servo driver diagnostic apparatus according to the present invention is equivalent to a servo driver in a servo driver diagnostic apparatus that diagnoses a servo driver that controls opening and closing of a governor valve in a power plant . Characteristic
A simulated servo driver with
Two alternating signals, a low level signal and a high level signal
Generates a test signal and a predetermined AC test signal
Input to the above servo driver, and output AC signal
The presence or absence of an abnormality is determined according to the size of the
The first mode diagnostic means for diagnosing iva and the simulated server
The driver must have the specified DC bias signal and
Input the AC test signal and output the AC
A bell is normal, and a high level is abnormal.
The second mode of self-diagnosis
The diagnostic means and the simulated servo driver are connected to the specified DC
Input the ass signal and the high level AC test signal above.
If the output of that AC component is at a low level, abnormal or high level
If the servo driver diagnostic device
With a third mode diagnostic means for self-diagnosis
Is.

(2) In the above (1), the first mode
Of the first mode by the diagnostic means of the card and the second mode
Second mode diagnosis and third mode diagnosis by the diagnostic means of
Periodically repeat the third mode diagnosis by disconnection means.
To do.

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. Embodiment 1 of the present invention will be described below 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 of a servo driver diagnostic device. Figure 2
Is a block diagram showing the configuration of the servo driver diagnostic device,
A system / B system servo driver diagnostic devices 14 and 15 in FIG.
It shows the configuration of.

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

In FIG. 2, reference numeral 21 is a servo driver card, which is the A-system / B-system servo driver card 12, 1 of FIG.
The actual valve opening signal and the AC test signal 101 are input, and the output 102 is a combined signal of 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) sine wave frequency reference signal 105 of a predetermined magnitude
To occur. A signal stop detection circuit 23 detects the stop of the frequency reference signal 105.

Reference numeral 24 is a test signal generator for generating the test signal 101, which has a built-in adder and has a frequency reference signal 105.
And the output signal 102 from the servo driver card 21 and the output signal 104 from the sample hold unit 25 are added and subtracted to generate the test signal 101.

Reference numeral 25 is a sample and hold section for sampling and holding the output signal 102 from the servo driver card 21, and 26 is a level detector.
The output signal 102 from is extracted by the filter 50 as an AC component, is rectified by the rectifier 61 as a DC component, and the signal of this DC component is compared with a preset predetermined value. The determination result signal 107 is transmitted. Reference numeral 27 is a control lodge 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 by using the switching device 3, and the governor steam valve 5 is opened / closed by the valve opening command which is the output. . If the A-system servo driver card 12 is abnormal, the governor steam valve 5 is opened / closed by 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 A system servo driver card 12 which is always used, and the B system servo driver diagnostic device 15 diagnoses the B system servo driver card 13 which is a standby system. 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 magnitude at a predetermined frequency, that is, an AC signal. The magnitude of the signal in this case is a high-level AC signal output by the level detection unit 26 described later. It has a signal.

The sample hold unit 25 samples and holds the output from the servo driver card 21, and the sampled and held output 104 serves as 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 is used as a feedback signal and becomes the subtraction input of the adder of the test signal generator 24. 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 hold unit 25 are canceled out, and the frequency reference signal 1
05 is output as the test signal 101. The servo driver card 21 sends 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 output by superimposing the AC component of the test signal 101 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 the load of the servo driver card 21, but the internal circuit of the servo driver card 21 has a frequency at which it 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 unsaturated region (proportional region) or in the saturated region. Output is obtained.

Therefore, as long as there is no failure such as sticking of circuit components inside the servo driver card 21, the output 102 of the servo driver card 21 is controlled by the closed loop to the valve opening command at the predetermined frequency of the high level test signal 101. The waveform becomes 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 the DC component, is cut by the filter 50, and only the AC component passes. The 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 larger than the set value.

If the frequency reference signal 105 of the frequency reference signal generating section 22 is a high level signal, the control logic section 27 outputs the determination result signal 107 to determine 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 which is the load
Therefore, the soundness of the servo driver card 21 can be constantly diagnosed.

Embodiment 2. In the first embodiment, only the diagnosis of the servo driver card 21 is performed, but in the second embodiment, the simulated servo driver unit and the changeover switch are provided inside the servo driver diagnosis device, so that the servo driver diagnosis device It enables self-diagnosis and improves the safety of diagnosis.

FIG. 3 shows an embodiment of the present invention in which a simulated servo driver section and a changeover switch are provided. Reference numeral 41 denotes a simulated servo driver unit, which is a bias signal generation unit that simulates a saturation signal, an adder that adds a bias signal and a test signal, and the addition result to which the servo driver card 21 is input.
And a servo drive with the same operating characteristics calculate and output.

Reference numerals 42, 43, 44, and 45 are switches for switching the closed loop of the simulated servo driver unit and the servo driver card, which are controlled by the control block unit 27. The switches 42 and 45 are turned on and the switches 43 and 44 are turned off.
In the case of, 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 self-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 apparatus using the simulated servo driver unit 41, a sine wave signal of a predetermined low level 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 non-detected and confirmed to be normal.

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

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

This closed loop test signal 201 is the difference between the sum of the output signal 104 of the sample and hold section 25 and the frequency reference signal 105 of the frequency reference signal generating section 22 and the output signal 202 of the simulated servo driver section 41 as a feedback signal. Is. The simulated servo driver unit 41
Applies a bias input (saturation signal) to output signal 20
2 is saturated (+ potential).

The sample and hold section 25 samples and holds the output signal 202 of the simulated 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 simulated servo driver unit 41 are canceled out, and as a result, the frequency reference signal 105 becomes the low level test signal 2
It is output as 01 and is input to the simulated servo driver unit 41.

By the control of this closed loop, the output 202 of the simulated servo driver section 41 has a waveform in which the saturation signal by the bias signal and the predetermined frequency of the low level test signal 201 are superimposed. This output 202 is input to the level detector as the detected waveform component 106 by the rectifier 61 after the AC component is extracted by the filter 50. The detected waveform component 10
Since 6 is a low level, it becomes less than the set value of the level detection unit 26, the self-diagnosis abnormality 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 higher than the set value even though the frequency reference signal generator 22 generates the low level frequency reference signal 105, the level detector 26 causes the self-diagnosis abnormality signal 203. And the control logic unit 27 outputs the self-diagnosis failure alarm 204.

Next, a high level test signal 3 of a predetermined frequency
The diagnostic operation by inputting 01 to the simulated servo driver unit 41 will be described. As shown in FIG. 3, the simulated servo driver unit 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 section 41 and the test signal generating section 24 form a closed loop as shown in FIG. The frequency reference signal generator 22 generates a high level frequency reference signal 105, and 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
Since the operation of is the same as the operation of the low level frequency reference signal, description thereof will be omitted.

When the high level test signal 301 is input to the simulated servo driver section 41, the output signal 302 becomes a signal in which the DC saturation signal due to the bias signal of the simulated servo driver section 41 and the high level test signal 301 are superimposed. . This output signal 302 has its AC component extracted by the filter 50, full-wave rectified by the rectifier 61, and the detected waveform component 10
It becomes 6 and is input to the level detection unit 26. In the level detector 26, since 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 abnormal signal 203 is not output.

In this way, the diagnostic device itself can be diagnosed. Although the bias signal of the simulated servo driver unit 41 is tested so that the output of the servo driver is saturated, it may be tested in a non-saturated region (proportional region).

Further, the switches 43 and 44 can be turned off and the switches 42 and 45 can be turned on to diagnose the servo driver card 21 at any time. Alternatively, the switches 43 and 44 and the switches 42 and 45 may be alternately switched to periodically diagnose 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 parts as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 51 is a bandpass filter that passes the frequency of the AC signal that is the frequency reference signal.

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

Fourth Embodiment 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 unit 27 turns on and off the switches 42, 43, 44 and 45,
As shown in FIG. 5, the test with the low level test signal of the simulated servo driver 41, the test with the high level test signal of the simulated servo driver 41, and the test with the high level test signal of the actual servo driver card 21 are performed. The diagnosis is executed while controlling the governor steam valve 5 at all times by repeating the cycle 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 done at the same time.

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

Sixth Embodiment In the above embodiment, the diagnosis of the servo driver card for controlling the governor steam valve used in the thermal power / nuclear power plant has been described, but the present invention can also be applied to the governor valve for hydraulic power generation. Further, the servo driver card can be applied not only to a card having a servo driver function such as a servo driver circuit. Further, in the first embodiment, the AC test signal is input to the servo driver for diagnosis 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]

As described above, according to the present invention,
Since the diagnosis of the servo driver and the diagnosis of the diagnosis device itself are switched and executed, both of them can be diagnosed and reliable diagnosis can be performed.

(2) Further, since the diagnosis of the servo driver and the diagnosis of the diagnostic device itself are periodically repeated, reliable diagnosis can be performed.

[0059]

[0060]

[0061]

[0062]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part relating 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 diagnostic device according to the first embodiment of the present invention.

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

FIG. 4 is a configuration diagram of a servo driver diagnostic device according to a third embodiment of the present invention.

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

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

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

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

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

[Explanation of symbols]

1 Valve controller A 2 Valve controller B 3 Switching device 5 Governor steam valve 11 Standby system 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 unit 42, 43,
44, 45 Switch 50 Filter 51 Bandpass 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 error alarm 201 Low Level test signal 202 Simulated servo driver output 203 Self-diagnosis abnormality signal 204 Self-diagnosis failure alarm 301 High-level test signal 401 Diagnosis stop command

Claims (2)

(57) [Claims] 1. A servo driver diagnostic device for diagnosing a servo driver for controlling opening / closing of a governor valve of a power plant, wherein a simulated servo drive having characteristics equivalent to those of the servo driver.
A low level signal and a high level signal as an AC test signal
Generate two AC test signals , input a predetermined AC test signal to the servo driver,
Check for abnormalities according to the magnitude of the output AC signal.
First mode diagnosis to judge and diagnose the above servo driver
Means and a predetermined DC bias signal on the simulated servo driver.
Input a low-level AC test signal and
Is normal if the output is low, abnormal if the output is high
Servo driver diagnosis device self-diagnosis
The second mode diagnostic means and a predetermined DC bias signal for the simulated servo driver
Input a high level AC test signal and
If the output of is low level, it is abnormal, if it is high level, it is normal
And the servo driver diagnostic device itself is self-diagnosed.
And a third mode diagnostic means.
Robot driver diagnostic device. 2. The servo driver diagnostic device according to claim 1.
In the first mode diagnosis by the first mode diagnosis means,
The second mode diagnosis by the mode diagnosis means and the third mode diagnosis
Periodically repeat the third mode diagnosis by the diagnostic means
Servo driver diagnostic device characterized by re-execution
Place