JP6471028B2 - Valve opening control device and control method thereof - Google Patents

Description

  Embodiments described herein relate generally to a valve opening control device and a control method thereof.

  FIG. 6 is a block diagram showing a configuration of a conventional valve opening degree control device 10. As shown in FIG. 6, the valve opening degree control device 10 includes a valve control circuit 20 and a monitoring switching circuit 30. The valve 1 is provided with a servo valve 6 in which two servo coils 3 and 3 are connected in parallel, and a valve opening degree sensor 2 for detecting the opening degree of the valve 1 is also provided.

  The valve control circuit 20 includes an excitation voltage generator 22, a servo current output circuit 24, and a self-system failure diagnosis circuit 26, and the excitation voltage a is supplied from the excitation voltage generator 22 to the valve opening sensor 2. The servo current b is supplied from the servo current output circuit 24 to the servo valve 6. Then, the opening / closing control of the valve 1 is performed by the positive / negative of the servo current b. The self-system failure diagnosis circuit 26 is a circuit for diagnosing the self-system valve control circuit 20 and detecting an abnormality. If any abnormality is detected in the self-system valve control circuit 20, an abnormality has occurred. A valve control circuit abnormality signal e indicating this is output to the failure signal monitoring circuit 34 of the monitoring switching circuit 30. Further, the valve control circuit 20 outputs a valve control circuit output state signal f indicating the output state of the valve control circuit 20 to the output state monitoring circuit 32 of the monitoring switching circuit 30.

  In the valve opening degree control device 10 as shown in FIG. 6, when the valve control circuit 20 is to be multiplexed, for example, duplexed, each of the excitation voltage generators 22 in the two valve control circuits 20 has an opening degree. The excitation voltage a can be supplied to the sensor 2. However, if the excitation voltage a is simultaneously supplied from the two excitation voltage generators 22 to one valve opening sensor 2, the excitation voltage generator 22 may be damaged. Therefore, it is necessary to selectively supply the excitation voltage a to the valve opening degree sensor 2 by switching the duplicated excitation voltage generator 22.

JP 2012-246889 A

  However, if the excitation voltage a is to be supplied from the two excitation voltage generators 22 to the valve opening degree sensor 2 without overlapping, it is necessary to provide a time lag for switching between the two excitation voltage generators 22. That is, there occurs a time during which neither of the two excitation voltage generators 22 supplies the excitation voltage a to the valve opening degree sensor 2. However, while the excitation voltage a is not supplied to the valve opening sensor 2, the valve opening sensor 2 cannot output the opening signal, so the opening signal of the valve 1 becomes zero, and the servo from the valve control circuit 20 There is a possibility that an opening direction signal may be output to the coil 3. Due to the signal in the opening direction, the valve 1 operates in the opening direction, and there is a possibility that the control target equipment such as a turbine to which the valve 1 is connected is led in a dangerous direction.

  Therefore, the present invention has been made in consideration of such points, and an object of the present invention is to provide a valve opening degree control device that avoids guiding the control target equipment to which the valve 1 is connected in a dangerous direction. To do.

The valve opening degree control device according to the present embodiment is
A valve opening degree control device comprising a plurality of valve control circuits each capable of independently performing a control operation related to the opening degree of a valve to be controlled, and a monitoring switching circuit for monitoring and switching the plurality of valve control circuits. Because
Each of the plurality of valve control circuits includes:
A sensor driving voltage generator for generating a sensor driving voltage to be supplied to a valve opening sensor for detecting the opening of the valve;
Sensor drive voltage supply control provided between the sensor drive voltage generator and the valve opening sensor, and controls supply of the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor. Circuit,
A self-diagnosis circuit that diagnoses the valve control circuit of the self-system and detects the occurrence of a failure;
An actuator control current supply circuit for supplying a control current to an actuator for controlling the operation in the opening direction and the operation in the closing direction of the valve;
With
The monitoring switching circuit performs a control operation on the valve to any one of the plurality of valve control circuits that operates normally, and
When the fault diagnosis circuit in the valve control circuit performing the control operation for the valve detects a failure, the monitoring switching circuit performs a switching process for switching the control operation to another valve control circuit that operates normally. The sensor drive voltage supply control circuit of the valve control circuit in which the failure has occurred stops supplying the sensor drive voltage to the valve opening sensor, and the actuator control current of the valve control circuit in which the failure has occurred The supply circuit stops supplying the control current to the actuator;
The sensor drive of the switching destination valve control circuit in the switching process after a predetermined time has elapsed after the sensor drive voltage supply control circuit of the failed valve control circuit has stopped supplying the sensor drive voltage The voltage supply control circuit starts supplying the sensor drive voltage to the valve opening sensor,
After the sensor drive voltage supply control circuit of the switch destination valve control circuit starts supplying the sensor drive voltage to the valve opening sensor, the actuator control current supply circuit of the switch destination valve control circuit Supplying a control current to the actuator;
It is characterized by that.

Further, the control method of the valve opening degree control device according to the present embodiment is as follows:
A plurality of valve control circuits each capable of independently performing a control operation related to the opening degree of the valve to be controlled, and a monitoring switching circuit for monitoring and switching the plurality of valve control circuits,
Each of the plurality of valve control circuits includes:
A sensor driving voltage generator for generating a sensor driving voltage to be supplied to a valve opening sensor for detecting the opening of the valve;
Sensor drive voltage supply control provided between the sensor drive voltage generator and the valve opening sensor, and controls supply of the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor. Circuit,
A self-diagnosis circuit that diagnoses the valve control circuit of the self-system and detects the occurrence of a failure;
An actuator control current supply circuit for supplying a control current to an actuator for controlling the operation in the opening direction and the operation in the closing direction of the valve;
A control method of a valve opening degree control device comprising:
The monitoring switching circuit performs a control operation on the valve to any one of the plurality of valve control circuits that operates normally, and
When the fault diagnosis circuit in the valve control circuit performing the control operation for the valve detects a failure, the monitoring switching circuit performs a switching process for switching the control operation to another valve control circuit that operates normally. The sensor drive voltage supply control circuit of the valve control circuit in which the failure has occurred stops supplying the sensor drive voltage to the valve opening sensor, and the actuator control current of the valve control circuit in which the failure has occurred The supply circuit stops supplying the control current to the actuator;
The sensor drive of the switching destination valve control circuit in the switching process after a predetermined time has elapsed after the sensor drive voltage supply control circuit of the failed valve control circuit has stopped supplying the sensor drive voltage The voltage supply control circuit starts supplying the sensor drive voltage to the valve opening sensor,
After the sensor drive voltage supply control circuit of the switch destination valve control circuit starts supplying the sensor drive voltage to the valve opening sensor, the actuator control current supply circuit of the switch destination valve control circuit Supplying a control current to the actuator;
It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the valve opening degree control apparatus which avoided guiding the control object installation to a danger direction can be provided.

FIG. 1 is a block diagram illustrating a configuration of a valve opening degree control device according to the first to third embodiments. FIG. 2 is a graph showing the relationship between the current value of the servo current output from the servo current output circuit of the valve opening degree control apparatus according to the first embodiment and time. FIG. 3 is a graph showing the relationship between the current value of the servo current output from the servo current output circuit of the valve opening degree control apparatus according to the second embodiment and time. FIG. 4 is a graph showing the relationship between the current value of the servo current output by the servo current output circuit of the valve opening degree control apparatus according to the third embodiment and time. FIG. 5 is a block diagram illustrating the configuration of the valve opening degree control device according to the fourth embodiment. FIG. 6 is a block diagram illustrating a configuration of a conventional valve opening degree control device.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
The valve opening control device according to the first embodiment stops the supply of the servo current to the servo valve while there is no opening signal from the valve opening sensor generated in the switching process of the duplicated valve control circuit. By doing so, the valve is operated in the closing direction by the action of the null bias provided in the valve itself, and the control target equipment is prevented from being led in the dangerous direction. More details will be described below.

  FIG. 1 is a block diagram illustrating a configuration of a valve opening degree control device 100 according to the first embodiment. As shown in FIG. 1, the valve opening degree control device 100 according to the present embodiment includes a first valve control circuit 120A, a second valve control circuit 120B, and a monitoring switching circuit 130. Yes. That is, the valve control circuits 120A and 120B are provided in a duplex manner, and are configured so that each can independently perform a control operation related to the opening degree of the valve 1 to be controlled.

  The first valve control circuit 120A includes an excitation voltage generator 122A, a servo current output circuit 124A, a self-system failure diagnosis circuit 126A, and a switch 128A. The excitation voltage generator 122A is connected to the opening degree sensor 2 via the switch 128A. For this reason, when the switch 128A is in the ON state, the excitation voltage a generated by the excitation voltage generator 122A is supplied to the opening degree sensor 2. Conversely, when the switch 128A is in the OFF state, the excitation voltage a generated by the excitation voltage generator 122A is not supplied to the opening degree sensor 2.

  The servo current output circuit 124A supplies the servo current b1 to the servo valve 6, and performs opening / closing control of the valve 1 by positive / negative of the servo current b1. For example, when the servo current b1 is a positive current, the servo valve 1 operates in the opening direction, and when the servo current b1 is a negative current, the servo valve 1 operates in the closing direction. As can be seen from this, the servo valve 6 performs control related to the operation in the opening direction and the operation in the closing direction of the valve 1 based on the supplied servo current b1. Here, the valve 1 is, for example, a steam valve, but may be another type of valve such as a hot water valve or an exhaust valve.

  The own system failure diagnosis circuit 126A diagnoses the valve control circuit 120A that is the own system, and detects the occurrence of a failure in the valve control circuit 120A. Then, the own system failure diagnosis circuit 126A outputs a valve control circuit abnormality signal e1 indicating whether or not a failure has occurred in the own valve control circuit 120A to the monitoring switching circuit 130. Separately from this, the valve control circuit 120 </ b> A outputs a valve control circuit output state signal f <b> 1 to the monitoring switching circuit 130. The valve control circuit output state signal f1 is a signal of f1 = (excitation voltage a) / (servo current b1), and indicates the output state of the valve control circuit 120A.

  The switch 128A is provided with a switch 128A between the exciting voltage generator 122A and the valve opening sensor 2. The switch 128A constitutes a sensor drive voltage supply control circuit that controls the supply of the servo current b1 to the valve opening sensor 2 in the present embodiment.

  The second valve control circuit 120B has the same configuration as the first valve control circuit 120A. That is, the second valve control circuit 120B is also configured to include an excitation voltage generator 122B, a servo current output circuit 124B, a self-system failure diagnosis circuit 126B, and a switch 128B. The excitation voltage a is supplied to the opening degree sensor 2 through the switch 128B, the servo current output circuit 124B supplies the servo current b2 to the servo valve 6, and the own system failure diagnosis circuit 126B monitors and switches the valve control circuit abnormality signal e2. The valve control circuit 120B outputs the valve control circuit output state signal f2 to the monitoring switching circuit 130.

  The monitoring switching circuit 130 is a circuit for monitoring and switching the valve control circuits 120A and 120B so that any one of the valve control circuits 120A and 120B that operates normally performs the control operation of the valve 1. And an output state monitoring circuit 132, a failure signal monitoring circuit 134, and a switching command output circuit 136.

  The output state monitoring circuit 132 receives the valve control circuit output state signal f1 from the first valve control circuit 120A and receives the valve control circuit output state signal f2 from the second valve control circuit 120B. The output state monitoring circuit 132 monitors the valve control circuits 120A and 120B based on the values of the valve control circuit output state signals f1 and f2. Particularly in the present embodiment, the output state monitoring circuit 132 monitors whether the servo current b1 or the servo current b2 is supplied to the servo valve 6 based on the valve control circuit output state signals f1 and f2. Based on the monitoring result, the control signal i is output to the switching command output circuit 136.

  The failure signal monitoring circuit 134 receives the valve control circuit abnormality signal e1 from the own system failure diagnosis circuit 126A in the first valve control circuit 120A, and from the own system failure diagnosis circuit 126B in the second valve control circuit 120B. The valve control circuit abnormality signal e2 is input. When the valve control circuit abnormality signal e1 or the valve control circuit abnormality signal e2 indicating that a failure has occurred is input to the failure signal monitoring circuit 134, the failure signal monitoring circuit 134 outputs the control signal h to the switching command output circuit 136. .

  The switching command output circuit 136 switches the valve control circuits 120A and 120B based on the input control signal h. Specifically, when a failure occurs in the first valve control circuit 120A, the control operation for the valve 1 is switched to the second valve control circuit 120B. On the other hand, when a failure occurs in the second valve control circuit 120B, the control operation for the valve 1 is switched to the first valve control circuit 120A.

  In the present embodiment, the excitation voltage generators 122A and 122B constitute a sensor drive voltage generator that generates an excitation voltage a that is a sensor drive voltage, and the switches 128A and 128B include the valve opening sensor 2. A sensor drive voltage supply control circuit that controls the supply of the sensor drive voltage to the self-system fault diagnosis circuits 126A and 126B diagnoses the self-system valve control circuit and detects the occurrence of a fault. The system fault diagnosis circuit is configured, and the servo valve 6 configures an actuator that controls the operation of the valve 1 in the opening direction and the closing direction, and the servo current output circuits 124A and 124B are provided in the actuator. An actuator control current supply circuit for supplying a control current is configured.

  Next, operation | movement of the valve opening degree control apparatus 100 which concerns on this embodiment is demonstrated. Here, when the valve control circuit 120A in the valve opening degree control device 100 performs a control operation on the valve 1, the monitoring switching circuit 130 causes the valve 1 to operate as a result of a failure in the first valve control circuit 120A. An example in which the valve control circuit that performs the control operation is switched to the second valve control circuit 120B and the control operation for the valve 1 is continued will be described.

  First, when the valve control circuit 120A is operating normally, the self-system failure diagnosis circuit 126A generates a valve control circuit abnormality signal e1 indicating that no failure has occurred in the valve control circuit 120A, as a monitoring switching circuit. This is output to the failure signal monitoring circuit 134. Further, the valve control circuit 120A outputs the valve control circuit output state signal f1 to the output state monitoring circuit 132 of the monitoring switching circuit 130. While the valve control circuit 120A is operating normally, the switch 128A is closed, and conversely, the switch 128B is open. For this reason, the excitation voltage a is supplied to the valve opening degree sensor 2 only from the excitation voltage generator 122A of the first valve control circuit 120A.

  When a failure occurs in the valve control circuit 120A during this control operation, the own system failure diagnosis circuit 126A detects this failure, and sends a valve control circuit abnormality signal e1 indicating that the failure has occurred to the failure signal of the monitoring switching circuit 130. Output to the monitoring circuit 134. The first valve control circuit 120A switches the switch 128A from the closed state to the open state. Thereby, supply of the excitation voltage a from the excitation voltage generator 122A to the valve opening degree sensor 2 is stopped. Since this excitation voltage a is a driving voltage for the valve opening sensor 2, the valve opening sensor 2 cannot be driven temporarily, and the output of the opening signal is temporarily stopped. Furthermore, the servo current output circuit 124A that has detected the valve control circuit abnormality signal e1 indicating the occurrence of a failure also stops the supply of the servo current b1 and sets the current value to 0A.

  FIG. 2 is a diagram illustrating the current values of the servo currents b1 and b2 output from the servo current output circuits 124A and 124B. In FIG. 2, the horizontal axis represents time, and the vertical axis represents current values that are output values of the servo currents b1 and b2.

  As shown in FIG. 2, at time T1, a failure of the first valve control circuit 120A is detected, the switching process to the second valve control circuit 120B is started, and the servo output from the servo current output circuit 124A is started. The current b1 becomes zero. For this reason, the valve 1 operates in the closing direction due to the null bias of the valve 1. That is, when the supply of the servo current to the servo valve 6 becomes zero, the valve 1 operates in the closing direction due to the null bias.

  As shown in FIG. 1 again, the failure signal monitoring circuit 134 that detects the valve control circuit abnormality signal e1 indicating the occurrence of the failure from the first valve control circuit 120A is connected to the second valve from the first valve control circuit 120A. A control signal h for switching control to the control circuit 120B is output to the switching command output circuit 136. Upon receiving this control signal h, the switching command output circuit 136 outputs a control signal d for switching control from the first valve control circuit 120A to the second valve control circuit 120B to the second valve control circuit 120B. To do.

  The second valve control circuit 120B to which the control signal d is input switches the switch 128B from the off state to the on state after a predetermined time has elapsed. As a result, the excitation voltage a from the excitation voltage generator 122B is supplied to the valve opening degree sensor 2 via the switch 128B. That is, the opening degree signal is normally output from the valve opening degree sensor 2. In addition, since a time lag of a predetermined length is provided between the time when the switch 128A is turned off and the time when the switch 128B is turned on, the excitation voltage generator 122A and the excitation voltage generator 122B are both excited. It is avoided that the voltage a is supplied to the valve opening degree sensor 2. In the present embodiment, a time lag having a predetermined length is inserted in the second valve control circuit 120B to which the control signal d for switching the control operation from the switching command output circuit 136 to the second valve control circuit 120B is input. However, the time lag having the predetermined length may be inserted on the monitoring switching circuit 130 side. That is, the monitoring switching circuit 130 to which the valve control circuit abnormality signal e1 indicating the occurrence of the failure from the first valve control circuit 120A is input, the switching command output circuit 136 performs the switching command output circuit 136 after a predetermined time has elapsed. The control signal d for switching the control operation to the second valve control circuit 120B may be output to the second valve control circuit 120B. In this case, the second valve control circuit 120B to which the control signal d is input can immediately switch the switch 128B from the off state to the on state.

  After the switch 128B is turned on and the supply of the excitation voltage a to the opening sensor 2 is started, the servo current output circuit 124B of the second valve control circuit 120B supplies the servo current b2 to the servo valve 6. To start. This is time T2 in FIG. That is, from the time T1 that is the start time of the switching process to the time T2 that is the end time of the switching process, neither of the servo currents b1 and b2 is supplied to the servo valve 6 and becomes 0A. After time T2 when the switching process from the first valve control circuit 120A to the second valve control circuit 120B is completed, the second valve control circuit 120B controls the valve 1 by the valve opening degree control device 100. Will continue.

  Here, the timing at time T2 in FIG. 2 can be variously set. For example, the servo current output circuit 124B may start supplying the servo current b2 immediately after the second valve control circuit 120B switches the switch 128B from the off state to the on state, that is, substantially simultaneously. . That is, in this embodiment, after the supply of the excitation voltage a to the opening sensor 2 is started, the supply of the servo current b2 to the servo valve 6 is started when the supply of the excitation voltage a and the servo current b2 is started. It also includes starting at substantially the same time. Further, the servo current output circuit 124B that detects that the excitation voltage a is supplied from the excitation voltage generator 122B to the valve opening sensor 2 may start supplying the servo current b2.

  As described above, according to the valve opening degree control device 100 according to the present embodiment, when the failure diagnosis circuit 126A detects a failure of the first valve control circuit 120A, the switch 128B is turned off from the on state. At the same time, the servo current b1 output from the servo current output circuit 124A is stopped. For this reason, it is possible to prevent the control target equipment such as the gas turbine to which the valve 1 is connected from moving in the closing direction due to the null bias of the valve 1 from moving in the dangerous direction. Furthermore, since the excitation voltage a is not supplied to the valve opening sensor 2 from both the excitation voltage generator 122A and the excitation voltage generator 122B, damage to the valve opening sensor 2 can be avoided.

(Second Embodiment)
In the first embodiment described above, when a failure is detected in the first valve control circuit 120A, the servo current output circuit 124A immediately cuts off the servo current b1 to 0A, but in the second embodiment, The servo current b1 gradually decreases with time, and finally reaches 0A. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

  FIG. 3 is a diagram showing a graph showing the relationship between the current values of servo currents b1 and b2 output by the servo current output circuits 124A and 124B according to the present embodiment and time, respectively, and FIG. 2 in the first embodiment described above. It is a figure corresponding to. In addition, since the structure of the valve opening degree control apparatus 100 which concerns on this embodiment is the same as that of FIG. 1 in 1st Embodiment mentioned above, the description is abbreviate | omitted.

  As shown in FIG. 3, in this embodiment, when a failure of the first valve control circuit 120A is detected at time T1, a switching process to the second valve control circuit 120B is started, and the servo current The servo current b1 output from the output circuit 124A is attenuated linearly to 0A at a constant rate of change with time. When the servo current b1 becomes 0A, the valve 1 operates in the closing direction due to the null bias of the valve 1. That is, when the supply of the servo current to the servo valve 6 is stopped, the valve 1 operates in the closing direction. The servo current b1 is the same as that of the first embodiment except that the waveform of the servo current b1 is different.

  When switching from the first valve control circuit 120A to the second valve control circuit 120B, even if the servo current output circuit 124A outputs the servo current b1 having the waveform as shown in FIG. 3, the current value of the servo current b1 is changed. By setting it to 0A, it is possible to avoid that the valve 1 operates in the closing direction with the null bias of the valve 1 and the control target equipment such as a gas turbine to which the valve 1 is connected goes in the dangerous direction.

  In the example of FIG. 3, when a failure of the first valve control circuit 120A is detected at time T1, the servo current b1 supplied by the servo current output circuit 124A is a straight line with a constant rate of change over time. However, the change of the servo current b1 is not limited to this. For example, it may be 0A in a curve from time T1 when the failure of the first valve control circuit 120A is detected. In other words, from time T1, the servo current b1 may be gradually decreased with time so that the current value finally becomes 0A.

(Third embodiment)
In the third embodiment, when the servo current output circuits 124A and 124B in the first embodiment and the second embodiment described above are modified and a failure occurs in the first valve control circuit 120A, the failure occurs. A servo current output circuit 124B outputs a servo current b2 having a current value larger than the current value of the servo current b1 immediately before the operation, and supplies the servo valve 6 with the servo current b2. Only the parts different from the first embodiment and the second embodiment described above will be described below.

  FIG. 4 is a graph showing the relationship between the current values of servo currents b1 and b2 output by the servo current output circuits 124A and 124B according to the present embodiment and time, respectively, and FIG. 2 in the first embodiment described above. FIG. 4 is a diagram corresponding to FIG. 3 in the second embodiment. In addition, since the structure of the valve opening degree control apparatus 100 which concerns on this embodiment is the same as that of FIG. 1 in 1st Embodiment mentioned above, the description is abbreviate | omitted.

  As shown in FIG. 4 and FIG. 1 described above, in this embodiment, when a failure of the first valve control circuit 120A is detected at time T1, the switching process to the second valve control circuit 120B is performed. The servo current b1 that is started and output from the servo current output circuit 124A becomes 0 A at time T1 as in the first embodiment. When the servo current b1 supplied to the servo valve 6 becomes 0 A, the valve 1 operates in the closing direction due to the null bias of the valve 1. That is, when the supply of the servo current to the servo valve 6 is stopped, the valve 1 operates in the closing direction.

  The second valve control circuit 120B, which is the switching destination, switches the switch 128B from the off state to the on state after a predetermined time has elapsed since the switch 128A of the first valve control circuit 120A has been turned off. . As a result, the excitation voltage a from the excitation voltage generator 122B is supplied to the valve opening degree sensor 2 via the switch 128B.

  Also, after the switch 128B is turned on and the supply of the excitation voltage a to the valve opening sensor 2 is started, the servo current output circuit 124B of the second valve control circuit 120B supplies the servo current b2 to the servo valve 6. To start. This is time T2 in FIG. At this time, for example, the current value of the servo current b1 is twice the current value of the servo current b1 immediately before the failure is detected. For this reason, the state of the valve 1 can be returned to the state before the start of the switching process from the first valve control circuit 120A to the second valve control circuit 120B due to a failure in a shorter time. Then, the control to the valve 1 by the valve opening degree control device 100 is continued by the second valve control circuit 120B.

  Also in the present embodiment, when switching from the first valve control circuit 120A to the second valve control circuit 120B, the supply of the servo current b1 to the servo valve 6 is stopped. Is operated in the closing direction, and it is possible to avoid that the control target equipment such as the gas turbine to which the valve 1 is connected goes in the dangerous direction. Furthermore, since the servo current b2 is supplied to the servo valve 6 at a current value, for example, twice the current value of the servo current b1 immediately before the failure is detected, the valve 1 can be returned to the state before the failure occurs more quickly. Can be returned.

  In the example of FIG. 4, the servo current output circuit 124B outputs a servo current b2 having a current value that is twice the current value of the servo current b1 immediately before the time T1 at which the failure is detected. This does not necessarily have to be 2 times, but may be n times (n> 1) such as 1.3 times, 1.5 times, and 3 times. In other words, if the servo current output circuit 124B supplies the servo current b2 having a current value larger than the current value of the servo current b1 immediately before the failure is detected to the servo valve 6 at time T2, It is possible to expect a similar effect of returning to the control state before the failure more quickly.

  In addition, the second embodiment described above can be applied in combination with the present embodiment. That is, the servo current b1 supplied by the servo current output circuit 124A may gradually decrease with time from the time T1 when the failure is detected, and the current value may finally become 0A.

(Fourth embodiment)
In the first to third embodiments described above, the valve opening degree control device 100 is configured to include two valve control circuits 120A and 120B. However, in the valve opening degree control device according to the fourth embodiment, It is configured to include n valve control circuits. Only the parts different from the first to third embodiments described above will be described below.

  FIG. 5 is a block diagram illustrating the configuration of the valve opening degree control apparatus 400 according to the fourth embodiment. As shown in FIG. 5, in this embodiment, the valve opening degree control device 400 is configured to include a plurality of valve control circuits, and each of the plurality of valve control circuits is independently controlled. A control operation related to the opening degree of a certain valve 1 can be performed. Specifically, the valve opening degree control device 400 includes n valve control circuits 120A, 120B,. Here, n is a natural number of 2 or more.

  Each of the n valve control circuits 120A, 120B... 120n has substantially the same configuration. That is, the excitation voltage generator 122n, the servo current output circuit 124n, and the own system failure diagnosis circuit 126n in the valve control circuit 120n are respectively the excitation voltage generator 122A and the servo current output in the first valve control circuit 120A. This corresponds to the circuit 124A and the own system failure diagnosis circuit 126A. Similar to the servo current output circuit 124A, the servo current output circuit 124n supplies the servo current bn to the servo valve 6. Similarly to the self-system failure diagnosis circuit 126A, the self-system failure diagnosis circuit 126n outputs the valve control circuit abnormality signal en to the failure signal monitoring circuit 134 of the monitoring switching circuit 130, and similarly to the valve control circuit 120A, The control circuit 120 n outputs the valve control circuit output state signal fn = (excitation voltage a) / (servo current bn) to the output state monitoring circuit 132 of the monitoring switching circuit 130.

  On the other hand, the monitoring switching circuit 130 according to the present embodiment includes a switching destination determination circuit 430 in addition to the output state monitoring circuit 132, the failure signal monitoring circuit 134, and the switching command output circuit 136 described above. . The switching destination determination circuit 430 receives the control signal i from the output state monitoring circuit 132 and the control signal h from the failure signal monitoring circuit 134, and performs control operations based on the control signal i and the control signal h. The next valve control circuit to be switched to is determined when the valve control circuit being performed fails. For example, when the valve control circuit abnormality signal e1 of the valve control circuit 120A performing the control operation indicates that a failure has occurred, another valve control circuit in which the valve control circuit abnormality signal e2... En does not indicate the occurrence of a failure. 120B... 120n, the switching destination determination circuit 430 selects one switching destination valve control circuit and outputs it to the switching command output circuit 136 as a control signal j. For example, when the control signal j indicates switching to the valve control circuit 120B, the switching command output circuit 136 performs switching processing from the valve control circuit 120A to the valve control circuit 120B based on the control signal j. The control signal d is output to the valve control circuit 120B.

  Servo currents b1, b2,..., Bn output from the servo current output circuits 124A, 124B,... 124n while switching from the failed valve control circuits 120A, 120B,. May be any pattern of the first to third embodiments described above. That is, the servo current output circuits 124A, 124B,... 124n may supply servo currents b1, b2,... Bn as shown in FIG. b2... bn may be supplied to the servo valve 6, or servo currents b1, b2... bn as shown in FIG.

  Also in this embodiment, when switching from the failed valve control circuits 120A, 120B,... 120n to the non-failed valve control circuits 120A, 120B, 120n, the valve 1 is closed by the null bias of the valve 1. It is possible to avoid the control target equipment such as the gas turbine to which the valve 1 is connected from moving in the danger direction.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof. Moreover, as a matter of course, these embodiments can be partially combined as appropriate within the scope of the present invention.

  Further, for example, in the description of the above-described embodiment, when the valve control circuit 120A in the valve opening control devices 100 and 400 is performing a control operation on the valve 1, a failure has occurred in the first valve control circuit 120A. Thus, the example of performing the control operation on the valve 1 by switching to the second valve control circuit 120B has been described, but the valve control circuit performing the control operation on the valve 1 is limited to the first valve control circuit 120A. In addition, the valve control circuit in which a failure occurs is not limited to the first valve control circuit 120A. For example, when the second valve control circuit 120B in the valve opening control device 100 performs a control operation on the valve 1, the first valve control circuit is caused by a failure in the second valve control circuit 120B. There is a possibility that the control operation for the valve 1 is continued by switching to 120A. The operation of the valve opening control device 100 in this case is also substantially the same as in the above-described embodiment.

100, 400: Valve opening control device, 120A, 120B ... 120n: Valve control circuit, 122A, 122B ... 122n: Excitation voltage generator, 124A, 124B ... 124n: Servo current output circuit, 126A, 126B ... 126n: Own system Failure diagnosis circuit, 128A, 128B ... 128n: switch, 130: monitoring switching circuit, 132: output state monitoring circuit, 134: failure signal monitoring circuit, 136: switching command output circuit, 430: switching destination determination circuit

Claims (8)

A valve opening degree control device comprising a plurality of valve control circuits each capable of independently performing a control operation related to the opening degree of a valve to be controlled, and a monitoring switching circuit for monitoring and switching the plurality of valve control circuits. Because
Each of the plurality of valve control circuits includes:
A sensor driving voltage generator for generating a sensor driving voltage to be supplied to a valve opening sensor for detecting the opening of the valve;
Sensor drive voltage supply control provided between the sensor drive voltage generator and the valve opening sensor, and controls supply of the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor. Circuit,
A self-diagnosis circuit that diagnoses the valve control circuit of the self-system and detects the occurrence of a failure;
An actuator control current supply circuit for supplying a control current to an actuator for controlling the operation in the opening direction and the operation in the closing direction of the valve;
With
The monitoring switching circuit performs a control operation on the valve to any one of the plurality of valve control circuits that operates normally, and
When the fault diagnosis circuit in the valve control circuit performing the control operation for the valve detects a failure, the monitoring switching circuit performs a switching process for switching the control operation to another valve control circuit that operates normally. The sensor drive voltage supply control circuit of the valve control circuit in which the failure has occurred stops supplying the sensor drive voltage to the valve opening sensor, and the actuator control current of the valve control circuit in which the failure has occurred The supply circuit stops supplying the control current to the actuator;
The sensor drive of the switching destination valve control circuit in the switching process after a predetermined time has elapsed after the sensor drive voltage supply control circuit of the failed valve control circuit has stopped supplying the sensor drive voltage The voltage supply control circuit starts supplying the sensor drive voltage to the valve opening sensor,
After the sensor drive voltage supply control circuit of the switch destination valve control circuit starts supplying the sensor drive voltage to the valve opening sensor, the actuator control current supply circuit of the switch destination valve control circuit Supplying a control current to the actuator;
The valve opening degree control apparatus characterized by the above-mentioned.   2. The valve opening degree according to claim 1, wherein the actuator control current supply circuit in the valve control circuit in which the failure has occurred immediately stops the supply of the control current when the switching process starts. Control device.   The actuator control current supply circuit in the valve control circuit in which a failure has occurred, gradually decreases the supply of the control current with the passage of time from the start of the switching process, and stops the supply of the control current. The valve opening degree control device according to claim 1.   After the switching process is completed, the actuator control current supply circuit in the switching target valve control circuit supplies the actuator control current supply circuit of the valve control circuit that detected the failure to the actuator immediately before the occurrence of the failure. The valve opening degree control device according to claim 1, wherein the control current is supplied to the actuator at a current value larger than a current value of the control current. The fault diagnosis circuits in the plurality of valve control circuits each output a valve control circuit abnormality signal indicating whether or not a fault has occurred in the valve control circuit of the own system to the monitoring switching circuit,
The monitoring switching circuit identifies a valve control circuit operating normally based on the input valve control circuit abnormality signal, and detects an abnormality of the valve control circuit performing a control operation on the valve. The valve opening degree control device according to any one of claims 1 to 4, wherein   When the actuator control current supply circuit of the valve control circuit in which the failure has occurred stops supplying the control current, the current value of the control current becomes 0A, and the valve operates in the closing direction by a null bias. The valve opening degree control device according to any one of claims 1 to 5.   The sensor drive voltage supply control circuits in the plurality of valve control circuits are each configured by a switch, and when supplying the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor, The switch is turned off when the switch is turned on and the supply of the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor is stopped. The valve opening degree control apparatus according to claim 6. A plurality of valve control circuits each capable of independently performing a control operation related to the opening degree of the valve to be controlled, and a monitoring switching circuit for monitoring and switching the plurality of valve control circuits,
Each of the plurality of valve control circuits includes:
A sensor driving voltage generator for generating a sensor driving voltage to be supplied to a valve opening sensor for detecting the opening of the valve;
Sensor drive voltage supply control provided between the sensor drive voltage generator and the valve opening sensor, and controls supply of the sensor drive voltage from the sensor drive voltage generator to the valve opening sensor. Circuit,
A self-diagnosis circuit that diagnoses the valve control circuit of the self-system and detects the occurrence of a failure;
An actuator control current supply circuit for supplying a control current to an actuator for controlling the operation in the opening direction and the operation in the closing direction of the valve;
A control method of a valve opening degree control device comprising:
The monitoring switching circuit performs a control operation on the valve to any one of the plurality of valve control circuits that operates normally, and
When the fault diagnosis circuit in the valve control circuit performing the control operation for the valve detects a failure, the monitoring switching circuit performs a switching process for switching the control operation to another valve control circuit that operates normally. The sensor drive voltage supply control circuit of the valve control circuit in which the failure has occurred stops supplying the sensor drive voltage to the valve opening sensor, and the actuator control current of the valve control circuit in which the failure has occurred The supply circuit stops supplying the control current to the actuator;
The sensor drive of the switching destination valve control circuit in the switching process after a predetermined time has elapsed after the sensor drive voltage supply control circuit of the failed valve control circuit has stopped supplying the sensor drive voltage The voltage supply control circuit starts supplying the sensor drive voltage to the valve opening sensor,
After the sensor drive voltage supply control circuit of the switch destination valve control circuit starts supplying the sensor drive voltage to the valve opening sensor, the actuator control current supply circuit of the switch destination valve control circuit Supplying a control current to the actuator;
A control method for a valve opening degree control device.

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