Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.Should be understood that, embodiment described herein, only for instruction and explanation of the present invention, is not limited to the present invention.
Fig. 1 is the schematic diagram of the control system of electric actuator according to one embodiment of the present invention.As shown in Figure 1, this control system comprises valve positioner 100 and control of valve position relay 200, for exporting valve position control signal to control of valve position relay 200, to control the action of electric actuator according to the valve position feedback signal from valve position feedback device.
Specifically, should be understood that, it is shown in Figure 2 that the control system of this electric actuator can also comprise valve position feedback device 400(), valve position feedback device 400 can be such as the valve position feedback device of any position (valve position) for detecting electric actuator, such as it can be mounted in the electric pneumatic converter on electric actuator, transmit valve position feedback signal by being connected with valve positioner 100 to valve positioner 100, its structure and working principle is conventionally known to one of skill in the art.Therefore, in order to not obscure protection scope of the present invention and theme, be no longer described in detail at this.
According to one embodiment of the present invention, this control system also comprises: valve position protective gear 300, valve positioner 100 is connected with described control of valve position relay 200 by valve position protective gear 300, according at least one in following, valve positioner 100 is also for judging whether electric actuator breaks down, and valve position protective gear actuating signal is exported when judging that electric actuator breaks down: valve position feedback rate of change, current valve position feedback signal, and the difference between current valve position feedback signal and control of valve position signal, valve position protective gear 300 is for disconnecting described control of valve position signal according to valve position protective gear actuating signal.
By this mode of execution; the real-time judge to valve position feedback fault can be realized; and according to above-mentioned Rule of judgment, valve positioner 100 is when judging that electric actuator breaks down; control of valve position is disconnected by starting valve position protective gear 300; namely the control of valve position signal exported is made not arrive electric actuator by control of valve position relay 200; thus electric actuator is failure to actuate (namely remaining on original position), avoid the generation causing security incident because of electric actuator misoperation.
According to one embodiment of the present invention, valve positioner 100 can judge electric actuator whether fault according to any one in following three conditions: valve position feedback rate of change, current valve position feedback signal and the difference between current valve position feedback signal and control of valve position signal.When arbitrary condition meets, valve positioner 100 starts valve position protection, and security of system is higher.
Wherein, described valve position rate of change is determined according to the valve position feedback signal gathered in the unit time by valve positioner.Such as, valve positioner 100 can the current valve position feedback signal (such as, magnitude of voltage or current value) of Real-time Collection, and according to the valve position feedback signal determination valve position feedback rate of change that (such as, in 1S) in the unit time gathers.
According to technological scheme of the present invention, valve positioner 100 is previously stored with valve position feedback change set rate, the prespecified range of valve position feedback signal and the predetermined value of valve position feedback signal and control of valve position signal difference, described set rate, prespecified range and predetermined value can set according to the needs of practical operation and operating experience, or, valve positioner 100 also can receive above-mentioned predefined parameter, such as by the artificial input etc. of operator, the present invention does not limit this.
When meet following in the condition of at least one time, valve positioner 100 judges that electric actuator there occurs fault and exports valve position protective gear actuating signal to valve position protective gear 300:
1) determined valve position feedback rate of change is greater than set rate (valve position feedback rate of change is out-of-limit); 2) current valve position feedback signal exceedes prespecified range (valve position feedback quality bad value); And 3) difference between current valve position feedback signal and control of valve position signal is greater than predetermined value (deviation between valve position feedback signal and control of valve position signal transfinites, and variation tendency is contrary).
When valve positioner 100 judges actuator failure, export valve position protective gear actuating signal, valve position protective gear 300 can disconnect described control of valve position signal (such as according to valve position protective gear actuating signal, valve position protective gear 300 can be relay, such as normally closed relay, be connected on control of valve position relay 200 with the control loop of electric actuator, for disconnecting when receiving valve position protective gear actuating signal thus disconnecting control loop), electric actuator is not arrived by control of valve position relay 200 to make the control of valve position signal exported, thus make electric actuator be failure to actuate (namely remaining on original position), avoid the generation causing security incident because of electric actuator misoperation.
According to one embodiment of the present invention, described valve positioner 100 can be the valve positioner in distributed control system (DCS).Utilize distributed control system, the fault of electric actuator caused due to the fault (such as controllable silicon damage) of servoamplifier can be eliminated further, also save cost simultaneously.In addition, also can adjust according to practical operation operating mode the parameter such as dead band and sensitivity, be easy to safeguard and realize.
According to one embodiment of the present invention, valve positioner 100 can export valve position protective gear shutdown signal when receiving reset instruction, valve position protective gear 300 can also be used for connecting described control of valve position signal (such as according to described valve position protective gear shutdown signal, described valve position protective gear 300 can be relay, such as normally closed relay, be connected on control of valve position relay 200 with the control loop of electric actuator, for disconnecting when receiving valve position protective gear actuating signal thus disconnecting control loop, and close when receiving valve position protective gear shutdown signal thus connect control loop).
Wherein, described reset instruction can be the instruction that related personnel is inputted by operator display screen or pressed corresponding reset button to input, or it also can pass through user's hand reset, and the present invention does not limit this.Adopt this mode of execution, user can be realized according to actual conditions (such as failture evacuation, or when needing to carry out the distant place under failure condition, manually-operable) can again connect control of valve position signal, operate with the subsequent control needed electric actuator.
Fig. 2 is the schematic diagram of the control system of example electric actuator according to another embodiment of the invention.As shown in Figure 2, this system can also comprise warning device 500, can be connected with valve positioner 100, for performing actuation of an alarm according to described valve position protective gear actuating signal.
Preferably, this warning device 500 can comprise any devices with warning effect suitably such as buzzer, tutorial light, display screen.Such as; when warning device 500 receives the valve position protective gear actuating signal from valve positioner 100; it can open tutorial light, buzzer, and/or display screen display font flicker causes the attention of on-the-spot related personnel, improves Security further and designs hommization more.
Should be understood that, valve position protective gear 300 of the present invention can be any suitable device that can realize above-mentioned functions.Such as, valve position protective gear 300 can be switch.Preferably, described valve position protective gear is relay.Further, preferably, the quantity of valve position protective gear 300 is corresponding with the quantity of control of valve position relay 200.Such as, the control system of this electric actuator can comprise two control of valve position relays 200, is respectively used to perform door opening action and close the door action, i.e. enabling relay and closed relay.Correspondingly, valve position protective gear 300 can be configured to two, to be respectively used to forbid door opening action and forbid action of closing the door, namely to prohibit open relay and prohibits and close relay.
In addition, should be understood that, the above-mentioned numerous embodiments of description independently can use and also can be combined in a variety of combinations, and those skilled in the art can come suitable selection and setting according to actual conditions.
Adopt the control system of electric actuator provided by the invention; this control system comprises valve position protective gear; valve positioner can disconnect control of valve position when judging that electric actuator breaks down by starting valve position protective gear, thus Timeliness coverage fault, on-call maintenance, improves the Security of control procedure.And; valve positioner in this control system can judge fault of electric actuator according to any one in valve position feedback rate of change, current valve position feedback signal and the difference between current valve position feedback signal and control of valve position signal; can start valve position protection as long as there is one to meet in above-mentioned three conditions, Security is higher.
Below the preferred embodiment of the present invention is described in detail by reference to the accompanying drawings; but; the present invention is not limited to the detail in above-mentioned mode of execution; within the scope of technical conceive of the present invention; can carry out multiple simple variant to technological scheme of the present invention, these simple variant all belong to protection scope of the present invention.
It should be noted that in addition, each concrete technical characteristics described in above-mentioned embodiment, in reconcilable situation, can be combined by any suitable mode, in order to avoid unnecessary repetition, the present invention illustrates no longer separately to various possible compound mode.
In addition, also can carry out combination in any between various different mode of execution of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.