JP2009221993A - Water turbine governor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water turbine governor capable of restricting a condition of a pilot valve wherein a foreign material in operating fluid hinders smooth operation of a pilot valve in operation of a power generating water turbine. <P>SOLUTION: A controller 7 transmits an electric signal to a converter 5 based on an instruction signal instructing operation of a pilot valve 8, and the converter 5 converts the electric signal to a mechanical signal so as to drive the pilot valve 8. The controller 7 computes a deviation between the operation quantity instructed by the electric signal and the real operation quantity of a spool 8a of the pilot valve 8 detected by an operation quantity detecting unit 17, and in the case wherein the deviation is within a set range, the controller 7 outputs an electric signal for operating the spool 8a of the pilot valve 8 in a direction instructed by the instruction signal, and in the case wherein the deviation is out of the set range, the controller 7 outputs an electric signal for driving the spool 8a of the pilot valve 8 in a direction opposite to the direction instructed by the instruction signal for a preset output time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulically driven hydraulic turbine governor having a converter that converts an electrical signal into a mechanical signal.

  A water wheel governor is used to control the rotational speed of the water turbine for power generation. There are two types of water wheel governors: a system using an electric actuator and a system using a hydraulic actuator. The electric actuator method is used for relatively small water turbines, and the hydraulic actuator method is used for relatively large water turbines. Most domestic and overseas hydropower plants use hydraulic actuator type water wheel governors. ing.

  Turbine oil is used as operation oil for the hydraulic actuator. The operating oil is gradually contaminated due to the effects of sliding abrasion powder of hydraulic equipment and oxidation due to contact with air, etc., so that the pilot valve of the hydraulic actuator is driven by foreign matter in the operating oil. There is a risk that the water turbine will stop due to failure.

  As a conventional technique for preventing the tightness of the pilot valve, there is a technique that forcibly slightly vibrates the pilot valve by applying an AC voltage to a converter coil of an electro-mechanical converter that drives the pilot valve (for example, patents). Reference 1).

Japanese Patent No. 2693600

  Therefore, the inventors of the present application have made extensive studies and prevented the accumulation of foreign matter in the operating oil by opening and closing the pilot valve at a certain frequency and allowing the operating oil to flow while the operation of the power generation turbine is stopped. Developed a technology to suppress the astringency of the pilot valve when the power generation turbine is started.

  However, during operation of the hydroelectric power plant, there is often no output fluctuation, and the range in which the pilot valve moves is limited to a substantially constant range. For this reason, foreign matter in the operating oil accumulates on the part outside the range where the pilot valve moves, and if the pilot valve moves more than the above range, there is a risk that the foreign object will become hard and uncontrollable and will not be able to continue operation. Yes, there is still room for improvement.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a water wheel governor that can suppress the agitation of a pilot valve due to foreign matter in operation oil during operation of a power generation water turbine. And

  To achieve the above object, the present invention provides a main pressure distribution valve that controls hydraulic oil that drives a guide vane drive device of a water turbine, a pilot valve that controls pilot oil that drives the main pressure distribution valve, and an electrical signal. A converter that converts the signal into a mechanical signal and drives the pilot valve; a detector that detects an operation amount of the pilot valve; and a controller that sends the electrical signal to the converter based on an instruction signal that instructs the operation of the pilot valve; The controller is configured to calculate a deviation between an operation amount of the pilot valve detected by the detector and an operation amount instructed by the electrical signal, and a deviation calculated by the operation unit is predetermined. A determination unit that determines whether the deviation is within a set range; and, when the deviation is within the set range, operates the pilot valve in a direction indicated by the instruction signal An output control unit that outputs the electrical signal that is driven in a direction opposite to the instruction direction of the instruction signal when the deviation is out of the setting range; .

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a pilot valve stiffens with the foreign material in operation oil during driving | operation of the water turbine for electric power generation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 2 is a system diagram of the water turbine governor according to the present embodiment.

  In FIG. 2, the water wheel governor includes a main pressure distribution valve 10 that controls hydraulic oil that drives a guide vane drive device of the water wheel, a pilot valve 8 that controls pilot oil that drives the main pressure distribution valve 10, and an electrical signal. Is converted into a mechanical signal to drive the pilot valve 8, a detector 17 that detects the operation amount of the pilot valve 8, and an electrical signal to the converter 5 based on an instruction signal that instructs the operation of the pilot valve 8 A controller 7, a hydraulic switching valve 11 that controls pilot oil between the main pressure distribution valve 10 and the pilot valve 8, and a turbine operation stop electromagnetic valve 12 that controls pilot oil that switches the hydraulic switching valve 11 are provided.

  The main pressure distribution valve 10 includes a valve body 60 and a drive unit 70 that drives the valve body 60.

  The valve main body 60 is a guide vane servo motor (not shown) serving as a guide vane drive device for a turbine using hydraulic oil supplied from a hydraulic pump (not shown) via a strainer (not shown) and a conduit 15. The hydraulic oil is supplied to or discharged from the guide vane servomotor, and the input port 10c for inputting the hydraulic oil from the hydraulic pump, and the output port 10a connected to the guide vane servomotor through a conduit (not shown), 10b, discharge ports 10d and 10e connected to the pressure oil tank 23, and a main plunger 9 for appropriately switching the connection state of the ports 10a to 10e. When the main plunger 9 is in the neutral position (the position shown in FIG. 2), the output ports 10a and 10b are closed, and the supply and discharge of the hydraulic oil to and from the guide vane servomotor are shut off. When the main plunger 9 is driven in the upward direction in the figure, the input port 10c and the output port 10a are connected, and hydraulic oil from the conduit 15 is supplied to the guide vane servomotor via the output port 10a. The output port 10b and the discharge port 10e are connected, the return oil from the guide vane servo motor is discharged to a pressure oil tank (not shown), and the guide vane servo motor is opened. When the main plunger 9 is driven downward in the figure, the input port 10c and the output port 10b are connected, and hydraulic oil from the pipe 15 is supplied to the guide vane servomotor through the output port 10b. The output port 10a and the discharge port 10d are connected, the return oil from the guide vane servomotor is discharged to a pressure oil tank (not shown), and the guide vane servomotor is closed.

  The drive unit 70 includes an oil chamber 37 connected to a pilot pump (not shown) via the pipe line 13, and an oil connected to the pilot valve 8 via the pipe line 31, the hydraulic pressure switching valve 11 and the pipe line 33. A chamber 38, a piston portion 9 a that is connected to the main plunger 9 and partitions between the oil chamber 37 and the oil chamber 38, and a stopper portion 30 that limits the operating range of the main plunger 9 are provided.

  The oil chamber 37 of the piston portion 9a is connected to the pilot pump via the pipe line 13, and is in a state where the pilot pressure from the pilot oil from the pilot pump is constantly applied during operation. A pipeline 36 branches from the pipeline 13, and the pipeline 36 is connected to the oil chamber 38 via the pilot valve 8, the pipeline 31, the hydraulic pressure switching valve 11, and the pipeline 33. At this time, since the pressure receiving area on the oil chamber 38 side is wider than that on the oil chamber 37 side, part of the pilot oil flowing through the pipeline 13 is switched between the pilot valve 8 and the hydraulic switching valve 11. When the oil is supplied to the oil chamber 38 through the pipes 36, 31, 33, the piston 9a is driven upward in the figure due to the difference in pressure receiving area, and the main plunger 9 is also moved upward in conjunction with this. Move to. On the other hand, when the oil chamber 38 is communicated with the pressure oil tank 23 via the pipelines 31 to 33 due to the switching state of the pilot valve 8 and the hydraulic switching valve 11, the piston portion 9a is moved downward along with the main plunger 9 in the figure. Driven. As will be described later, when the pilot valve 8 is switched to the neutral position, the pilot oil in the pipes 36, 31, 33 and the oil chamber 38 is retained, and the piston portion 9a and the main plunger 9 are positioned at that time. Held in.

The stopper portion 30 includes a flange 30b connected to the main plunger 9,
And a stopper 30a for limiting the driving range of the flange 30b. By restricting the driving range of the flange 30b by the stopper 30a, the movable range of the main plunger 9 connected to the flange 30b is limited. The flange 30b is provided with a lever 80, and the lever 80 is driven integrally with the main plunger 9. Accordingly, the pilot valve sleeve 8b of the pilot valve 8 moves up and down following the operation of the lever 80 and the main plunger 9.

  The pilot valve 8 controls the flow of hydraulic oil from a pilot pump (not shown) guided through the pipe line 13 to drive the main pressure distribution valve 10, and includes a pilot valve sleeve 8b which is a valve box, A spool 8a, which is a valve body slidably provided in the pilot valve sleeve 8b, and a spring 8c for urging the pilot valve sleeve 8b toward the lever 80 of the main pressure distribution valve 10 are provided. The pilot valve sleeve 8 b has an input port, an output port, and a discharge port. The output port is connected to the hydraulic pressure switching valve 11 via a conduit 31, and the discharge port is connected to the pressure oil tank 23 via a conduit 32. And is connected to a pilot pump (not shown) via pipes 13 and 36. When the spool 8a is in a neutral position (the position shown in the drawing) with respect to the pilot valve sleeve 8b, the pilot valve 8 blocks the flow of pressure oil between the pipes 31, 32, 36, and the spool 8a When the valve sleeve 8b is in the upper position (open position) in the figure, the flow of pressure oil between the pipe lines 31, 36 is allowed and the flow of pressure oil between the pipe lines 31, 32 is blocked. When the spool 8a is driven to the lower position (closed position) in the drawing with respect to the pilot valve sleeve 8b, the flow of the pressure oil between the pipes 36 and 31 is interrupted and the pipes 31 and 32 are connected. Allow the flow of pressure oil between.

  The pilot valve sleeve 8b of the pilot valve 8 is pressed in the direction opposite to the force of the spring 8c by the lever 80 described above of the main pressure distribution valve 10, and moves up and down following the lever 80 by the force of the spring 8c. .

  The converter 5 is an electro-mechanical converter (for example, an electric actuator) that converts an electric signal into a mechanical signal (mechanical operation), and drives the spool 8 a of the pilot valve 8 based on the electric signal from the controller 7.

  The operation amount detector 17 detects the operation amount (for example, operation direction and speed) of the spool 8a of the pilot valve 8, and inputs the detection signal to the controller 7 via the transmission line 17a.

  The hydraulic switching valve 11 controls the flow of pressure oil between the pipe line 31 and the pipe line 33, is connected to the pilot valve 8 via the pipe line 31, and is connected to the main pressure distribution valve 10 via the pipe line 33. Connected with. The hydraulic switching valve 11 has an open position 11b (position shown in FIG. 2) that allows the flow of pressure oil between the pipe line 31 and the pipe line 33, and a flow of pressure oil between the pipe line 31 and the pipe line 33. And a closed position 11a for guiding the pressure oil in the pipe line 33 to the pressure oil tank 23 through the pipe line 34. The position of the hydraulic switching valve 11 is controlled by a control signal (pilot signal) from the water turbine operation stop solenoid valve 12, and when the control signal is received from the water turbine operation stop electromagnetic valve 12, the position is switched to the open position 11b. When there is no (tank pressure), the position is switched to the closed position 11a by the biasing force of the spring.

  The water turbine operation stop solenoid valve 12 controls the pilot pressure (control signal) supplied from the pilot pump (not shown) to the pilot pressure receiving portion of the hydraulic switching valve 11 via the pipeline 14. A position (operating position) 12a that allows the flow of pressure oil 14 and a position (stop position) 12b that blocks the flow of pressure oil in the conduit 14 and connects the pressure receiving portion of the hydraulic switching valve 11 to the pressure oil tank; have. The position of the electromagnetic valve 12 for stopping the turbine operation is controlled by a control signal (electric signal) from a host control device (not shown).

  The controller 7 controls the operation of the converter 5, and based on an instruction signal input from an unillustrated input means (higher control device or the like) and a detection signal input from the operation amount detector 17, An instruction signal (electric signal) is calculated and input to the converter 5 via the transmission line 7a. Next, the processing contents of the controller 7 will be described in detail.

  FIG. 1 is a diagram illustrating a part of the control circuit of the controller 7.

  The circuit shown in FIG. 1 includes a subtractor 21, an adder 22, an absolute value calculation element 1, comparators 2a, 2b, 2c, timers 3a, 3b, 3c, signal selector switches 4a, 4b, 4c, AND elements 18a, 18b, 18c, and various calculation elements of the NOT element 19 are appropriately combined.

  The subtractor 21 calculates a deviation between the command value 6 and the detection signal input from the operation amount detector 17, inputs the calculation result to the absolute value calculation element 1, and sets the value a to each of the comparators 2b and 2c. input.

  The command value 6 is a command value that instructs the converter 5 to drive the spool 8a of the pilot valve 8 in the opening direction (upward in FIG. 2) or in the closing direction (downward in FIG. 2). Input by the device. The command value 6 is a positive value when the instruction direction of the instruction signal is an open direction (open instruction), and a negative value when the instruction direction of the instruction signal is a close direction (close instruction).

  The absolute value calculation element 1 calculates the absolute value of the calculation result input from the subtractor 21, and inputs the calculated value as a value a to the comparator 2a.

  The comparator 2a compares the absolute value (value a) input from the absolute value calculation element 1 with the set value (value b) input from the set value 20a. Here, the setting value 20a to be compared with the value a is whether or not the difference between the indicated position by the command value 6 of the spool 8a of the pilot valve 8 and the actual position is within an allowable range, that is, the command value 6 is set to the spool 8a. This is a reference value for determining whether the operation is following, and is input in advance by an input device (not shown). When value a <value b (when it is within the allowable range), 0 (zero) is set as the comparison result, and when value a> value b (when it is outside the allowable range), 1 is set as the comparison result from the comparator 2a. Input to the timers 3a and 3b.

  When the comparison result input from the comparator 2a is 0 (zero), the timer 3a inputs 0 (zero) to the AND element 18a. When the input comparison result is 1, the counting starts from the time when the comparison result is input, and is 0 (zero) within a predetermined reference time (for example, 5 seconds), after the reference time has elapsed (after time is up) ) Inputs 1 to the AND element 18a. When 0 (zero) is input as a comparison result from the comparator 2a after the time is up, 0 (zero) is input to the AND element 18a.

  The AND element 18a calculates the logical product of the operation command 16 and the value input from the timer 3a, and inputs the calculation result to the timer 3c and the AND element 18b. Here, the operation command 16 is a command value indicating whether the operation or stop of the water turbine is instructed by a host control device (not shown). If the operation of the water turbine is instructed, 1 is instructed to stop. If it is, it is 0 (zero).

  The timer 3c inputs 0 (zero) to the NOT element 19 when the calculation result input from the AND element 18a is 0 (zero). When the input calculation result is 1, counting starts from the time the calculation result is input, and 0 (zero) is set within a predetermined reference time (for example, 2 seconds), after the reference time has elapsed (after time is up). ) Inputs 1 to the NOT element 19. Further, when 0 (zero) is input as an operation result from the AND element 18 a after the time is up, 0 (zero) is input to the NOT element 19.

  The NOT element 19 inputs 1 when the value input from the timer 3c is 0 (zero), and inputs 0 (zero) when the value is 1 to the AND element 18b.

  The AND element 18b calculates the logical product of the calculation result input from the AND element 18a and the calculation result input from the NOT element 19, and inputs the calculation result to the signal changeover switch 4c as the value Z1. That is, the value Z1 = 1 during the period from the start of counting of the timer 3c to the time-up, and Z1 = 0 otherwise.

  When the comparison result input from the comparator 2a is 0 (zero), the timer 3b inputs 0 (zero) to the AND element 18c. When the input comparison result is 1, the count starts from the time when the comparison result is input, and is 0 (zero) within a predetermined reference time (for example, 10 seconds), after the reference time has elapsed (after the time is up) ) Inputs 1 to the AND element 18c. When 0 (zero) is input as a comparison result from the comparator 2a after the time is up, 0 (zero) is input to the AND element 18c.

  The AND element 18c calculates the logical product of the operation command 16 and the value input from the timer 3b, and inputs the calculation result to a higher-level control device (not shown). Here, when the timer 3b expires, an abnormal signal for notifying the host controller of the abnormality of the pilot valve 8 is output. In other cases, the output signal to the host controller is 0 (zero), indicating that the pilot valve 8 is operating normally.

  The comparator 2b compares the calculation result (value a) input from the subtractor 21 with the reference value 20b (referred to as value b). Here, the reference value 20b to be compared with the value a is a reference value (= 0) for determining whether the command value 6 from the host controller is an open command or a close command. If value a <value b (= 0) (when the instruction signal is a close command), 0 (zero); if value a> value b (= 0) (when the instruction signal is an open command), set 1 The value (comparison result) Z1 is input to the signal selector switch 4a.

  The signal changeover switch 4a inputs the value X to the adder 22 when the comparison result (value Z1) input from the comparator 2b is 0 (zero), and the value Z2 when the comparison result (value Z1) is 1. To do. Here, the value X is a value of the set value 40a and is set to 0 (zero). On the other hand, the value Z2 is the value of the closing command 41a, which is a command value that drives the converter 5 and instructs the pilot valve 8 to drive the spool 8a in the closing direction. The close command 41a is set in advance by an input device (not shown) or the like.

  The comparator 2c compares the calculation result (value a) input from the subtractor 21 with the reference value 20c (referred to as value b). Here, the reference value 20c to be compared with the value a is a reference value (= 0) for determining whether the command value 6 from the host controller is an open command or a close command. When value a <value b (= 0) (when the instruction signal is a close command), 1 is set, and when value a> value b (= 0) (when the instruction signal is an open command), 0 (zero) is set. The value (comparison result) Z1 is input to the signal selector switch 4a.

  The signal changeover switch 4b inputs the value X to the adder 22 when the comparison result (value Z1) input from the comparator 2c is 0 (zero), and the value Z2 when the comparison result (value Z1) is 1. To do. Here, the value X is a value of the set value 40b and is set to 0 (zero). On the other hand, the value Z2 is the value of the opening command 41b, which is a command value that drives the converter 5 and instructs the pilot valve 8 to drive the spool 8a in the opening direction. The opening command 41b is set in advance by an input device (not shown) or the like.

  The adder 22 adds the instruction signal (electric signal) of the converter 5 inputted from the signal changeover switch 4a and the signal changeover switch 4b, and inputs it to the signal changeover switch 4c as a value Z2. That is, when the calculation result of the subtracter 21 is positive, the close command 41a (value Z2) from the signal changeover switch 4a is input to the input changeover switch 4c, and when it is negative, the open signal 41b from the signal changeover switch 4b is input. .

  The signal changeover switch 4c electrically outputs the value X (command value 6) when the calculation result (value Z1) input from the AND element 18b is 0 (zero), and the value Z2 when the calculation result (value Z1) is 1. The signal is input to the converter 5 as a signal.

  The operation of the present embodiment configured as described above will be described.

  During the water turbine operation, when an operation command is input from a higher-level control device (not shown), the controller 7 switches the operation stop solenoid valve 12 to the operation position 12a and switches the hydraulic pressure switching valve 11 to the open position. When a command value 6 for instructing the operation of the spool 8a is input from a host controller (not shown), the controller 7 uses the command value 6 and the detection signal from the operation amount detector 17 to convert the converter 5 An instruction signal (command value) is generated and input as an electric signal. Converter 5 drives pilot valve 8 based on the electrical signal from controller 7.

  Next, the output of the controller 7 and the operation of the pilot valve 8 driven as a result will be described for each state of the pilot valve 8.

(1) When the pilot valve 8 operates normally In this case, since the deviation between the command value 6 from the host controller and the detection signal from the operation amount detector 17 is within the set range, the comparison result of the comparator 2a is The value Z1 input to the signal changeover switch 4c from the AND element 18b becomes 0 (zero) and becomes 0 (zero). As a result, the value X, that is, the command value 6 from the host controller is directly input from the controller 7 from the signal changeover switch 4c.

  At this time, the signal fed back from the controller 7 to the upper control device (not shown) via the AND element 18c is 0 (zero), and it is confirmed that the operation of the pilot valve 8 is normal even on the upper control device side. The

  When the command value 6 is an open command, the spool 5a is driven to the upper position (open position) in the figure by the converter 5, and the oil chamber 37 of the main pressure distribution valve 10 from the pilot pump (not shown) via the pipeline 13 is provided. A part of the pilot oil supplied to the oil chamber 38 is supplied to the oil chamber 38 via the pipelines 36, 31, 33. As a result, the main plunger 9 is driven upward in the drawing in conjunction with the piston portion 9a, and hydraulic oil supplied from the hydraulic pump (not shown) via the strainer (not shown) and the pipeline 15 is output. While being supplied to the guide vane servomotor via the port 10a, the return oil from the output port 10b is discharged to a pressure oil tank (not shown), and the guide vane servomotor (not shown) is opened.

  On the other hand, when the command value 6 is a close command, the spool 8a is driven to the lower position (closed position) in the figure by the converter 5, and the pilot oil in the oil chamber 38 is pressurized oil tank via the pipes 31-33. 23 is discharged. As a result, the main plunger 9 is driven downward in the drawing in conjunction with the piston portion 9a, and hydraulic oil supplied from the hydraulic pump (not shown) via the strainer (not shown) and the pipe line 15 is output. While being supplied to the guide vane servomotor through the port 10b, the return oil from the output port 10a is discharged to a pressure oil tank (not shown), and the guide vane servomotor (not shown) is closed.

(2) When the pilot valve 8 does not operate as commanded For example, the foreign matter in the pilot oil hinders the operation of the spool 8a, and the deviation between the command value 6 and the detection signal from the operation amount detector 17 deviates from the set range. In this case, the comparison result of the comparator 2a becomes 1, and the timer 3a and the timer 3b start counting. At this point in time, the command value output from the signal changeover switch 4c to the converter 5 is the value X, that is, the command value 6, and the output from the AND element 18c to the host controller (not shown) is 0 indicating a normal state. (Zero). That is, during the counting of the timers 3a and 3b, the operation command similar to that at the normal time described above is continued.

  As a result, the comparison result of the comparator 2a is returned to 0 (zero) before the reference time (for example, 5 seconds) elapses (before time-up) and the timer 3a returns to 0 (zero) after the spool 8a operates in the indicated direction. , 3b, the signal changeover switch 4c continues to input the command value 6 to the converter 5 as an electric signal. In this case, the guide vane servomotor of the water wheel normally opens or closes as described above.

  On the other hand, if the comparison result of the comparator 2a has not yet returned to 0 (zero) when the timer 3a times out, the timer 3c starts counting from the time point when the timer 3a finishes counting, and the timer 3c starts counting. The value Z2 is input to the converter 5 as an electric signal from the signal changeover switch 4c until a predetermined reference time (for example, 2 seconds) elapses from the time point. That is, the controller 7 instructs the converter 5 to operate in a direction opposite to the command value 6 from the host control device for a certain time counted by the timer 3c.

  During this time, for example, if the spool 8a is not reluctant and is driven reversely by an appropriate stroke, the spool 8a operates in accordance with the instruction of the command value 6 at least for that stroke, so when the timer 3c expires, The signal selector switch 4c switches the output to the converter 5 to the value X, that is, the command value 6 from the host controller.

  As a result of the previous reverse drive, for example, if the foreign matter is removed and the movement of the spool 8a is not hindered, the normal operation described in (1) above is restored. On the other hand, when the clogging of the foreign matter is not eliminated and the spool 8a still does not operate according to the command value 6, the controller 7 executes the process described above in (2) again and commands reverse driving.

(3) When the spool 9a is stiff Even if the spool 8a of the pilot valve 8 is stiff due to foreign matter and is inoperable, even if the reverse drive of the spool 8a is commanded by the process (2) above If the spool 8a does not move from this position, the subtraction signal of the subtractor 21 remains out of the set range, and the counter 3b continues without being reset even if the counter 3c times out. As a result, when a predetermined reference time (for example, 10 seconds) elapses from the time when the timer 3b shown in (2) starts counting, 1 indicating an abnormal state is output from the AND element 18c to a higher-level control device (not shown). Then, abnormality processing (for example, stoppage of water turbine operation, etc.) is executed by the host control device.

  The effect in this Embodiment comprised as mentioned above is demonstrated.

  As described above, during operation of the hydroelectric power plant, there is often no output fluctuation, and the range in which the spool 8a of the pilot valve 8 moves is limited to a substantially constant range. For this reason, foreign matter in the operating oil accumulates in a portion outside the range in which the spool 8a moves, and there is a risk that the foreign matter will be astringent when the spool 8a moves more than the above range.

  For example, in a hydroelectric power plant with a turbine installed between the upper and lower tanks, when controlling the water level of the upper tank to be constant, the amount of water flowing into the upper tank changes rapidly. Therefore, the range in which the spool 8a moves is limited to a substantially constant range. However, when the water level of the upper water tank suddenly rises due to heavy rain or the like, control is performed to rapidly lower the water level of the upper water tank. Therefore, the spool 8a moves larger than the above range, and the accumulated operation oil The foreign matter may cause the spool 8a to become stiff and become uncontrollable, making it impossible to continue operation.

  On the other hand, in the present embodiment, when the spool 8a moves greatly and becomes stuck due to accumulated foreign matter, the spool 8a is driven in a direction opposite to the instruction direction of the instruction signal for a certain period of time, and the instruction signal is again transmitted. By driving in the indicated direction, it is possible to eliminate the accumulation of foreign matters that cause solid astringency, and thus it is possible to suppress the spool 8a from becoming astringent.

  Further, it is physically difficult to operate the spool 8a simultaneously with the input of the instruction signal from the host control device, and a delay occurs even when the spool 8a is not tight, and the instruction signal indicates the spool 8a. There is a risk that it will be determined that the motion is not following. However, in this embodiment, a reference time longer than the inevitable operation delay time is set in advance, and the operation of the spool 8a follows the instruction signal until the reference time elapses after the instruction signal is input. Since it is determined that it is not determined that it is not, it is possible to avoid unnecessary reverse driving when the spool 8a is in a normal state when it is not tight.

  Further, since the length of the time (reference time) for reversely driving the spool 8a can be limited (set), the main plunger 9 operates unintentionally when the spool 8a is reversely driven more than necessary. , It can suppress the runaway of the main aircraft.

  In addition, since the time (reference time) for reversely driving the spool 8a can be set short and the spool 8a can be operated shockingly, it is possible to more easily eliminate the astringency (accumulation of foreign matter) of the spool 8a. .

  Further, when the spool 8a becomes hard and cannot be driven, an abnormal signal is sent to the host control device, so that the host control can be promptly performed by the host control device, and the water turbine can be safely operated. Can be controlled.

  A second embodiment of the present invention will be described.

  In this embodiment, the number of times that the deviation between the command value 6 and the detection signal from the operation amount detector 17 deviates from the set range is counted, and a signal is output according to this number.

  FIG. 3 is a diagram showing a part of the control circuit of the controller 7A according to the present embodiment. In the figure, the same components as those shown in FIG.

  In FIG. 3, the controller 7A according to the present embodiment includes a counter 43d, a comparator 2d, a set number of times 20d, and an OR element 50 in addition to the configuration shown in the first embodiment.

  The AND element 18a calculates the logical product of the operation command 16 and the value input from the timer 3a, and inputs the calculation result to the timer 3c, the AND element 18b, and the counter 43d. Here, the operation command 16 is a command value indicating whether the operation or stop of the water turbine is instructed by a host control device (not shown). If the operation of the water turbine is instructed, 1 is instructed to stop. If it is, it is 0 (zero).

  The counter 43d counts the number of times the input value from the AND element 18a has changed from 0 (zero) to 1, and inputs the result (number of times) to the comparator 2d as the value a. In addition, the counter 43d resets the number of times counted every predetermined time (for example, every 24 hours) to 0 (zero).

  The comparator 2d compares the number of times (value a) input from the counter 43d with the set number of times (value b) input from the set number of times 20d. Here, the set number of times 20d to be compared with the value a is a reference value (for example, 10 times) for determining whether or not the number of occurrences of solid jam on the spool 8a of the pilot valve 8 is within an allowable range, and is an input device (not shown) For example, it is input in advance. When value a <value b (when it is within the allowable range), 0 (zero) is set as the comparison result. When value a> value b (when it is outside the allowable range), 1 is set as the comparison result from the comparator 2d. Input to the OR element 50.

  The AND element 18 c calculates the logical product of the operation command 16 and the value input from the timer 3 b and inputs the calculation result to the OR element 50. That is, 1 is input from the AND element 18c to the OR element 50 when the timer 3b has timed up, and 0 (zero) otherwise.

  The OR element 50 calculates the logical product of the comparison result input from the comparator 2d and the value input from the AND element 18c, and inputs the calculation result to a higher-level control device (not shown). Here, when the timer 3b expires, or when the count number of the counter 43d exceeds the set number of times 20d, an abnormality signal for notifying the host controller of the abnormality of the pilot valve 8 is output. In other cases, the output signal to the host controller is 0 (zero), indicating that the pilot valve 8 is operating normally.

  Other configurations are the same as those of the first embodiment.

  The operation of the present embodiment configured as described above will be described.

  Also in the present embodiment, as in the first embodiment, when the turbine 7 is in operation, the controller 7A sets the operation stop solenoid valve 12 to the operation position 12a when an operation command is input from a host controller (not shown). The hydraulic switch valve 11 is switched to the open position. When a command value 6 for instructing the operation of the spool 8a is input from a higher-level control device (not shown), the controller 7A makes the converter 5 based on the command value 6 and the detection signal from the operation amount detector 17. An instruction signal (command value) is generated and input as an electric signal. Converter 5 drives pilot valve 8 based on the electrical signal from controller 7A.

  Next, the output of the controller 7A and the operation of the pilot valve 8 driven as a result will be described for each state of the pilot valve 8. In the operation of the present embodiment, (1) when the pilot valve 8 operates normally, and (3) when the spool 9a is stiff, the operation is the same as in the first embodiment. Is omitted.

(2) When the pilot valve 8 does not operate as commanded For example, the foreign matter in the pilot oil hinders the operation of the spool 8a, and the deviation between the command value 6 and the detection signal from the operation amount detector 17 deviates from the set range. In this case, the comparison result of the comparator 2a becomes 1, and the timer 3a and the timer 3b start counting. At this point in time, the command value output from the signal changeover switch 4c to the converter 5 is the value X, that is, the command value 6, and the output from the AND element 18c to the host controller (not shown) is 0 indicating a normal state. (Zero). That is, during the counting of the timers 3a and 3b, the operation command similar to that at the normal time described above is continued.

  As a result, the comparison result of the comparator 2a is returned to 0 (zero) before the reference time (for example, 5 seconds) elapses (before time-up) and the timer 3a returns to 0 (zero) after the spool 8a operates in the indicated direction. , 3b, the signal changeover switch 4c continues to input the command value 6 to the converter 5 as an electric signal. In this case, the guide vane servomotor of the water wheel normally opens or closes as described above.

  On the other hand, if the total number of times that the timer 3a has timed out exceeds a predetermined number of times (for example, 10 times) when the timer 3a has timed out, an error is detected from the OR element 50 to a host control device (not shown). 1 indicating the state is output, and an abnormality process (for example, operation stop of the water turbine, etc.) is executed by the host control device.

  Further, when the cumulative number of times the timer 3a has timed up does not exceed a predetermined number of times (for example, 10 times), the comparison result of the comparator 2a is still 0 (zero) when the timer 3a has timed up. When the timer 3a does not return, the timer 3c starts counting from the time point when the timer 3a finishes counting, and from the time point when the timer 3c starts counting until a predetermined reference time (for example, 2 seconds) elapses, The value Z2 is input to the converter 5 as an electric signal. That is, the controller 7A instructs the converter 5 to operate in a direction opposite to the command value 6 from the host controller for a certain time counted by the timer 3c.

  During this time, for example, if the spool 8a is not reluctant and is driven reversely by an appropriate stroke, the spool 8a operates in accordance with the instruction of the command value 6 at least for that stroke, so when the timer 3c expires, The signal selector switch 4c switches the output to the converter 5 to the value X, that is, the command value 6 from the host controller.

  As a result of the previous reverse drive, for example, if the foreign matter is removed and the movement of the spool 8a is not hindered, the normal operation described in (1) above is restored. On the other hand, when the clogging of the foreign matter is not eliminated and the spool 8a still does not operate according to the command value 6, the controller 7A executes the process described above in (2) again and commands reverse driving.

  Other operations are the same as those in the first embodiment.

  Also in the present embodiment configured as described above, the same effects as those of the first embodiment can be obtained.

  In addition, when the spool 8a is stuck, even if the reverse drive of the spool 8a is repeated and the firmness of the spool 8a is not resolved, an abnormal signal is input to the host control device to take measures such as stopping the main engine. It is possible to control the operation of the water turbine more safely.

It is a figure which shows a part of control circuit of the controller which concerns on the 1st Embodiment of this invention. 1 is a system diagram of a water turbine governor according to a first embodiment of the present invention. It is a figure which shows a part of control circuit of the controller which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

1 Absolute value calculation elements 2a, 2b, 2c, 2d Comparators 3a, 3b, 3c Timers 4a, 4b, 4c Signal selector switch 5 Converter 6 Command value 7, 7A Controller 7a Transmission line 8 Pilot valve 8a Pilot valve sleeve 8b Spring 9 Main plunger 9a Piston part 10 Main pressure distribution valve 11 Hydraulic switching valve 12 Electromagnetic valve 13-15 for turbine operation stop Pipe 16 Operation command 17 Operation amount detector 17a Transmission line 18a, 18b, 18c AND element 19 NOT element 20a Set value 21 Subtractor 22 Adder 23 Pressure oil tank 30 Stopper portions 31 to 36 Pipe lines 37 and 38 Oil chamber 43d Counter 50 OR element

Claims (3)

A main pressure distribution valve that controls the hydraulic oil that drives the guide vane drive device of the turbine,
A pilot valve that controls the pilot oil that drives the main pressure distribution valve;
A converter that converts an electrical signal into a mechanical signal and drives the pilot valve;
A detector for detecting an operation amount of the pilot valve;
A controller that sends the electrical signal to the converter based on an instruction signal that instructs operation of the pilot valve;
The controller calculates a deviation between an operation amount of the pilot valve detected by the detector and an operation amount instructed by the electrical signal;
A determination unit for determining whether the deviation calculated by the calculation unit is within a predetermined setting range;
When the deviation is within the set range, the electrical signal for operating the pilot valve in the indicated direction of the instruction signal is output, and when the deviation is outside the set range, a predetermined output time, A water wheel governor comprising: an output control unit that outputs the electric signal that is driven in a direction opposite to a direction indicated by the instruction signal. The water wheel governor according to claim 1,
The said output control part outputs an abnormal signal, when the said deviation is outside a setting range, after passing the said output time, The water turbine governor characterized by the above-mentioned. The water wheel governor according to claim 1,
The water wheel governor, wherein the output control unit outputs an abnormal signal when the set number of times is determined within a predetermined time that the deviation is outside the set range.

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