JP3470171B2 - Control device for multi-coil servo valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for a multi-coil type servo valve, and more particularly to a controller for a multi-coil type servo valve having a redundant configuration used in power generation equipment and the like.

[0002]

2. Description of the Related Art In a conventional multi-coil type servo valve controller, as shown in FIG. 1 of JP-A-63-108403, in order to improve system reliability, an arithmetic controller has a redundant structure. A method is provided in which a signal selection device is installed so as to straddle the redundant system controller, and each operation amount output from the redundant system controller is selected by a median value or an average value, and then sent to the operation end. Also, regarding the calculation in the controller of each redundant system,
The one with an integral element corrects the redundant system imbalance due to the superposition of the circuit error, so that the corresponding signals in other systems are constantly monitored, and when the deviation exceeds a certain value, it is regarded as a true value by the majority voting theory. The median value or the value obtained by adding a bias to the median value is overwritten to correct the redundant system imbalance.

[0003]

The above-mentioned conventional apparatus has the following drawbacks. (1) A redundant system in which a plurality of redundant systems are installed in order to improve reliability. However, since the signal selection circuit part such as the median value or the average value is a common part, the whole system functions by the down of this common part. Since it disappeared, the system reliability depended heavily on the reliability of this common part, and the deterioration of reliability was unavoidable. (2) During maintenance / maintenance, each system has a common part, not an independent part. Therefore, it is necessary to consider the common part such as manual maintenance. The factors that occurred were large. Originally
Human error is said to be smaller in independent individual maintenance than in maintenance that takes common parts into consideration. (3) When the integration exit of the own system deviates from the set value or more by the mutual diagnosis of each redundant system, the exit of the integral element gain is overwritten to the median value. The value suddenly changed to the median (the ideal is to gradually approach the median).

An object of the present invention is to smoothly correct a redundant system imbalance and improve system reliability when a multi-coil type servo valve is driven by a redundant system.
It is an object of the present invention to provide a controller for a multi-coil type servo valve suitable for facilitating maintenance.

[0005]

In order to solve the above-mentioned problems, a plurality of arithmetic controllers and servo coils at the operating ends are installed to form a redundant configuration, and the arithmetic controllers of each redundant system are independently provided with a central controller. Value selection means is provided,
The output value of each PI controller is input to the median value selection means of each redundant system via the transmission network, and the median value selected from the output values of each PI controller by the median value selection means and the output value of the PI controller of its own system The redundant system unbalance value is obtained from the deviation of the redundant system, and the redundant system unbalance value is used as a correction value for the redundant system unbalance to correct the valve opening command value of the redundant system servo valve in which the unbalance has occurred based on the correction value. . Here, as the valve opening command value of the servo valve, a pressure command value obtained by subtracting the actual pressure value from the deviation value between the pressure command and the redundant system unbalance value is input to the PI controller, and is output by the calculation of the PI controller.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a single-shaft gas turbine combined cycle power generation system as an example of an application target of the present invention. The output of the gas turbine 11 is specified by the relationship between the fuel flow rate by the fuel flow rate control valve 16 and the compressed air flow rate by the inlet guide vanes 17. In this gas turbine combined cycle, the waste heat of the gas turbine 11 is used to generate steam by the waste heat recovery boiler 14, the steam is sent to the steam turbine 12, and the steam flow rate is adjusted by the steam flow control valve 18. To be done. As shown in FIG. 2, the gas turbine 11, the steam turbine 12, and the generator 13 are connected to the same shaft, and the torque generated by the gas turbine 11 and the steam turbine 12 causes the generator 13 installed coaxially to rotate. ,Generate electricity. In such a configuration, the control device 15 is mainly operated by the fuel flow rate control valve 1.
6, an inlet guide vane 17, and a steam flow control valve 18.

[0007] These valves are required to have accuracy and quick response to the opening due to the nature of control such as speed-controlled load control as a shaft system. Therefore, the hydraulic servo shown in FIG. It is composed of a combination of a hydraulic pressure regulating valve (multi-coil type servo valve) consisting of a cylinder and a differential transformer for measuring the opening degree. In the hydraulic pressure regulating valve shown in FIG. 3, the inner cylinder of the cylinder 20 is the fuel flow rate control valve 16 and the inlet guide vane 1.
7. Directly connected to the steam flow control valve 18 to control the valve opening. The operation when the cylinder 20 is operated in the direction indicated by A will be described with reference to FIG. 3 wrapped around the same iron core 23
When a control current flows through the coil 22, the torque motor 19
Rotates the iron core 23 according to the combined magnetomotive force of the three coils 22. A refueling pipe 24 is attached to the iron core 23,
Depending on the direction in which the torque of the torque motor is applied, the oil supply pipe 24
The direction of oil flow is controlled. If torque is applied to A ′ by the current of the three coils 22, the oil in the oil supply pipe 24 flows in the direction indicated by a. Then, oil is supplied to the cylinder 20 as indicated by the arrow a, and the piston in the cylinder 20 moves in the A direction by the hydraulic pressure. At this time, since the differential transformer (opening gauge) 3 is attached to the piston in the cylinder as shown in FIG. 3, the position of the cylinder 20, that is, the valve opening is measured. Here, the reason why three coils 22 are wound around the same iron core 23 is to improve reliability against disconnection of the winding of the valve. Three
Since the two coils 22 are wound around the same iron core 23, the total value of the currents flowing through the three windings is electrically significant. Moreover, even if a part of the coil 22 is broken,
Since the magnetomotive force can be generated by the remaining coil 22, the operation can be continued, and the reliability of the hydraulic pressure regulating valve as the operating end is improved. Further, since the valve opening of the hydraulic pressure adjusting valve is determined by the amount of oil supplied, the valve as a whole has a property having an integral element. In the servo loop of the control system, the coil 22 to the differential transformer 3
By forming a control system with a closed loop up to the opening of
Together with the integral element of the valve itself, it is possible to control the valve opening to match the opening command value without error.

FIG. 1 is a structural example of a controller for a multi-coil type servo valve showing an embodiment of the present invention. Here, 3
A coil type servo valve controller (triple redundant system) will be described. In FIG. 1, 1 is an operating end of a hydraulic pressure regulating valve (multi-coil type servo valve), 2 is a servo amplifier, 3 is an opening gauge (differential transformer), 4 is a pressure gauge, 5 is a PI controller, and 6 is an opening. Command, 6'is the true opening command with the median selected, 7 is the pressure command, 7'is the corrected pressure command value, 8 is the opening deviation, 9 is the pressure deviation, 10 is the median selection circuit, 21
Is a transmission network, a to c are arithmetic controllers,
a'-c 'are high-speed operation parts, (A)-(C) are opening commands fetched by the operation controllers a-c through the transmission network 21, and e is a redundant system unbalanced value. Here, the control current to the three coils 22 described above is supplied by the amplifier 2 independent of each system. The command value to the amplifier 2 is given by the opening deviation 8 between the opening command 6 and the differential transformer (opening meter) 3. As described above, the hydraulic pressure adjustment valve, which is the operating end 1, has the integral characteristic as a whole, so the opening is adjusted until the opening deviation 8 is zero, that is, the steady deviation disappears. Further, when prompt response is required for the control responsiveness to the pressure fluctuation of the operating end 1, as shown in the high-speed operation parts a ′ to c ′, a configuration by analog hardware or a digital controller configuration capable of high-speed operation is provided. Is required.

Next, the operation of this embodiment will be described. The opening command value 6 is a pressure command value 7'calculated from the pressure command value 7 and the redundant system unbalance value e in the calculation controllers a to c.
The gain by the PI controller 5 is given to the deviation 9 between the actual pressure measured by the pressure gauge 4 and the actual pressure measured by the pressure gauge 4 to obtain the difference. Unbalanced value of redundant system e
Inputs the opening command values 6 of the calculation controller of its own system and the calculation controller of the other system to (A) to (C) of the median value selection circuit 10 through the transmission network 21, respectively. It is obtained as a deviation signal between the output true opening command 6 ′ and the own system opening command value 6.
The true opening instruction 6'is from (A) of the median selection circuit 10 to
The opening command value is obtained by selecting the median value of the opening command values 6 of the own system and the other system inputted in (C). Now, when the respective systems are normally performing control without error, the values of the respective systems are in balance, and the respective control current values supplied from the amplifiers 2 to 3 coils 22 of the respective systems also flow. However, if a measurement error occurs in the bubble opening degree of the opening degree meter 3, the pressure measurement value of the pressure gauge 4, or the like, an imbalance occurs in the redundant system. For example, when an unbalance occurs in the arithmetic controller a system, the opening command value 6 of the a system is (A) of the central value selection circuit 10 of the own system a.
At the same time, it is input to (A) of each median value selection circuit 10 of other systems b and c through the transmission network 21, and at the same time, (B) of the median value selection circuit 10 of its own system a, In (C), the opening command values 6 of the other systems b and c are input through the transmission network 21. The median selection circuit 10 of the own system a is the median selection circuit 1 of the other systems b and c.
The true opening command 6'is selected independently of 0, the redundant system unbalance value e is obtained from the deviation between the opening command value 6 of the own system a and the true opening command 6 ', and the pressure command value The deviation between 7 and the unbalanced value e of the redundant system is taken as the pressure command value 7'of the controller a system for calculation. Then, the deviation 9 between the pressure command value 7 ′ and the actual pressure by the pressure gauge 4 is input to the PI controller 5. In this case, that is, even if the unbalanced value causes the deviation 9 to be overbalanced by the integral element of the PI controller 5 and saturates the opening command value 6 of the system a, the median value selection circuit of the system a Reference numeral 10 compares the corresponding opening degree command values 6 of the respective systems with each other, performs mutual diagnosis of the own system a, and judges that the opening degree command value 6 of the own system a has deviated, the median value of the triple system. Is selected as the true opening command 6 ′ and is overwritten, and the deviation from the opening command value 6 of the system a is obtained as a redundant system unbalanced value e based on this overwritten central value, and based on this value e The pressure command value 7 at the inlet of the PI controller is corrected so that the value at the PI controller outlet of the system a is not saturated. The same applies when an unbalance occurs in the computing controllers b system and c system. Therefore, in this embodiment,
Independently, the unbalance of the redundant system is corrected smoothly and the unbalance of the redundant system is prevented in advance, and the value of the PI controller exit of the own system suddenly changes from the deviated value to the median value. Can be prevented.

Here, when the redundant system is saturated, the control current should be 0 after the opening of the hydraulic pressure control valve is fixed, but unbalance of the redundant system occurs and the redundant system becomes Due to the saturation, the bias current always flows, and the controllability deteriorates. Deterioration of controllability is because the control current of the saturated system continues to flow as a saturation current regardless of the opening command value and the actual opening, resulting in poor responsiveness of valve operation and steady operation. When the winding in which the current is flowing is broken, the steady saturation current is suddenly cut off, which causes a temporary change in the valve opening. At this time, in the conventional device, the imbalance of each system can be corrected by providing a signal selection circuit such as a median selection circuit that spans each system for the opening command value 6.
A common part is generated for each system, which deteriorates system reliability and causes factors for human error.

On the other hand, in the present embodiment, as described above, each system is provided with the median value selection circuit to make the redundant system controller completely independent in terms of hardware and to transmit the opening command value of each system. By transmitting it through the network and calculating the deviation from the opening command value as the redundant system unbalance value based on the median value, the unbalance of the redundant system is smoothly corrected and the unbalance of the redundant system is prevented in advance. It is possible to prevent the value at the exit of the PI controller of the own system from suddenly changing from the deviated value to the median value. In addition, since each system is provided and operated completely independently, it is possible to reduce the factors that cause human error such as performing maintenance after maintenance, for example, after completely powering off only the system a. . Further, since there is no common part between the redundant systems, the reliability of the system does not largely depend on the reliability of the common part, and the system reliability is improved as a whole.

[0012]

As described above, according to the present invention,
In a controller for a multi-coil type servo valve configured with a multiple redundant system, it is possible to smoothly correct an imbalance due to a circuit error or the like between the redundant systems while leaving each redundant system in an independent hardware state. Further, it is possible to improve the reliability of the system and reduce the factor of human error at the time of maintenance and maintenance of the system. As a result, controllability is expected to be improved by the unbalance correction.

[Brief description of drawings]

FIG. 1 is a configuration example of a controller for a multi-coil servo valve according to an embodiment of the present invention.

FIG. 2 shows an example of an object to which the present invention is applied.

FIG. 3 is a schematic configuration diagram of a multi-coil type servo valve according to the present invention.

[Explanation of symbols]

1 Operating end of hydraulic pressure control valve (multi-coil type servo valve) 2 Servo amplifier 3 Position gauge 4 pressure gauge 5 PI controller 10 Median value selection circuit 15 Control device 16 Fuel flow control valve 18 Steam flow control valve 19 Torque motor 20 cylinders 21 Transmission network 22 3 coils 23 iron core 24 Refueling pipe ac controller for calculation a '~ c' High-speed operation part

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16K 37/00 G05B 9/03

Claims (4)

(57) [Claims] 1. A controller for a multi-coil servo valve, which calculates an opening command value of a servo valve by a calculation controller having a PI controller and supplies an operation current to a servo coil according to the opening command value. A plurality of the arithmetic controller and servo coils at the operating end are installed to form a redundant configuration, and each arithmetic controller of each redundant system is provided with a central value selecting means independently of each other.
The output value of each PI controller is input to the median value selecting means of each redundant system via a transmission network, and the median value selected from the output values of each PI controller by the median value selecting means and the output of the PI controller of its own system. The redundant system unbalance value is obtained from the deviation from the value, and the redundant system unbalance value is used as a correction value for the redundant system unbalance, and the opening command value of the servo valve of the redundant system in which the unbalance has occurred based on the correction value. A controller for a multi-coil type servo valve, characterized in that 2. A controller for a multi-coil type servo valve, which calculates an opening command value of a servo valve by a calculation controller having a PI controller and supplies an operation current to a servo coil according to the opening command value. The operation controller and the servo coil at the operating end in a redundant configuration, the median value selecting means independently provided in each operation controller of each redundant system, and the output value of each PI controller are described in each redundant system. A transmission network for inputting to the median value selecting means, and the redundant system unbalance value is obtained from the deviation between the median value selected from the output values of the PI controllers by the median value selecting means and the output value of the own PI controller. , The redundant system unbalance value is used as a correction value of the redundant system unbalance, and the opening degree of the servo valve of the redundant system in which the unbalance has occurred based on the correction value. Control apparatus for a multi-coil servo valve and correcting values. 3. The opening command value for the servo valve according to claim 1, wherein the servo command opening command value is a pressure command value obtained by subtracting an actual pressure value from a deviation value between the pressure command and the redundant system unbalance value in the PI controller. Is input and is output by the calculation of the PI controller. 4. The pressure controller according to claim 1 or 2, wherein the PI controller has a high-speed arithmetic configuration, and a pressure command value obtained by subtracting an actual pressure value from a deviation value between the pressure command and the redundant system unbalance value is given to the PI controller. A control device for a multi-coil type servo valve, which inputs and outputs a valve opening command value of the servo valve by high-speed calculation of the PI controller.