Dual-card dual-control servo control system with redundancy function and control method thereof

Abstract

The present invention relates to a dual-card dual-control servo control system with redundant functions, which includes: two servo control cards, the two output ends of the servo control card are respectively connected to two servo valves, and the servo valve is connected to system equipment; the servo control card includes: a command input signal end, and also includes: an LVDT feedback signal end connected to the system equipment, and a servo valve core feedback signal end connected to one of the servo valves. The beneficial effect of the present invention is that the two servo control cards control the two servo valves at the same time, and maintain the normal operation of the steam turbine equipment and the control system in the event of a servo control card or servo valve failure. Reduce the number of shutdowns of steam turbine equipment, reduce operating costs, and increase the reliability and stability of valve control.

Description

Technical Field

[0001] The present invention relates to a controller and a control method, and in particular to a dual-card dual-control servo control system with redundant functions and a control method thereof. Background Art

[0002] In the steam turbine control system, valve control is the key control point. According to the input of the valve opening command and the feedback of the valve position, the servo controller outputs the control signal to control the valve opening and closing, thus completing the valve control of the steam turbine.

[0003] At present, servo controllers are widely used in the field of steam turbine control system technology, but they are limited to single-card single-valve control. Once the controller fails, the servo valve cannot work normally, affecting the operation of the entire steam turbine control system. In order to meet the control requirements of field applications, increase the reliability and stability of valve control, and reduce economic losses, the present invention proposes a servo controller with redundancy function. Summary of the invention

[0004] The above object of the present invention is achieved through the following technical solutions:

[0005] A dual-card dual-control servo control system with redundant function, comprising: two servo control cards, wherein the two output ends of the servo control card are respectively connected to two servo valves, and the servo valves are connected to system equipment; the servo control card comprises: an instruction input signal end, and also comprises: an LVDT feedback signal end connected to the system equipment, and a servo valve core feedback signal end connected to one of the servo valves.

[0006] In the dual-card dual-control servo control system with redundant function as described above, two solenoid valves are connected between the servo valve and the system equipment, and the control ends of the two solenoid valves are connected to one of the servo control cards.

[0007] As described above, the dual-card dual-control servo control system with redundant function, wherein the servo control card includes a first servo output end and a second servo output end, and the servo valve includes: a first coil and a second coil, and the first servo output end of one of the servo control cards is connected to the first coil of one of the servo valves, and the second coil of another of the servo valves.

[0008] As described above, the dual-card dual-control servo control system with redundant function, wherein the servo control card comprises: a TXD interface and a RXD interface, and the TXD interface of one servo control card is connected to the RXD interface of another servo control card.

[0009] As described above, the dual-card dual-control servo control system with redundant function, wherein the servo control card includes: a valve position display port, a servo output display port, a DO alarm indication port, and an LED indication port.

[0010] A control method for a dual-card dual-control servo control system with redundant function, wherein two servo control cards communicate through UART port cross wiring; the two servo control cards receive command input signals, LVDT feedback signals, and servo valve core feedback signals; the servo control cards are adjusted by PID algorithm to give servo output current, and give current output display indicating the current valve position, as well as current output display of servo output.

[0011] In the control method of the dual-card dual-control servo control system with redundant function as described above, the microprocessor inside the servo control card outputs the corresponding LED working status indication according to whether the RXD reception is normal.

[0012] The control method of the dual-card dual-control servo control system with redundant functions as described above, wherein the servo control card acquires the input circuit break detection of the command input circuit, the LVDT feedback circuit, and the circuit break detection function of the servo output. When the above faults are detected, the servo control card switches to the fault card, the DO channel controls the relay to output an alarm signal, and the hardware circuit is used to shut down the servo output current of the fault card to prevent the servo valve from being damaged.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: two servo control cards control two servo valves at the same time, and maintain the normal operation of the steam turbine equipment and the control system in the event of a servo control card or servo valve failure. The number of shutdowns of the steam turbine equipment is reduced, the operating cost is reduced, and the reliability and stability of valve control are increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The invention discloses a circuit block diagram of a dual-card dual-control servo control system with redundant functions. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0016] Figure 1 This is the circuit block diagram of the dual-card dual-control servo control system with redundant function of the present invention, please refer to Figure 1A dual-card dual-control servo control system with redundant function, including: two servo control cards, two output ends of the servo control card are respectively connected to two servo valves, and the servo valve is connected to the system equipment; the servo control card includes: a command input signal end, and also includes: an LVDT feedback signal end connected to the system equipment, and a servo valve core feedback signal end connected to a servo valve. The two servo control cards include: a first servo control card 1, a second servo control card 5, and the two servo valves include: a first servo valve 2, and a second servo valve 4.

[0017] Furthermore, two solenoid valves are connected between the servo valve and the system equipment, and the control ends of the two solenoid valves are connected to a servo control card. The first servo valve 2 is connected to the system equipment through the first solenoid valve 31 and the second solenoid valve 32, and the second servo valve 4 is connected to the system equipment through the third solenoid valve 33 and the fourth solenoid valve 34.

[0018] Furthermore, the servo control card includes a first servo output end and a second servo output end, and the servo valve includes: a first coil (coil A) and a second coil (coil B). The first servo output end of a servo control card is connected to the first coil of a servo valve and the second coil of another servo valve.

[0019] Furthermore, the servo control card includes: a TXD interface and a RXD interface, and the TXD interface of one servo control card is connected to the RXD interface of another servo control card.

[0020] Furthermore, the servo control card includes: a valve position display port, a servo output display port, a DO alarm indication port, and an LED indication port.

[0021] Specifically, in the implementation process of the present invention, the servo controller includes two servo control cards for simultaneous monitoring and control. The main control logic of the servo control card is to receive command input, sample LVDT feedback signal, servo valve core feedback signal, adjust through PID algorithm, give servo current output, and give current output display indicating current valve position, as well as current output display of servo output. The servo control card provides functions such as input circuit break detection of command input circuit, LVDT feedback circuit, circuit break detection of servo output current, etc. When the above faults are detected, the DO channel controls the relay to output an alarm signal, and the working status is indicated by the LED. The core of dual-card dual control is to cross-control the servo output current to coils A and B. For the first servo control card 1, the servo output channel 1 outputs to coil A of the first servo valve 2, and the servo output channel 2 outputs to coil B of the second servo valve 4. For the second servo control card 5, the servo output channel 1 outputs to coil A of the second servo valve 4, and the servo output channel 2 outputs to coil B of the first servo valve 2.

[0022] Furthermore, the present invention also discloses a control method for a dual-card dual-control servo control system with redundant function, wherein two servo control cards communicate via UART port cross-wiring; the two servo control cards receive command input signals, LVDT feedback signals, and servo valve core feedback signals, and the servo control cards are adjusted by PID algorithm to give a servo output current, and give a current output display indicating the current valve position, as well as a current output display of the servo output.

[0023] Furthermore, the microprocessor inside the servo control card outputs a corresponding LED working status indication according to whether the RXD reception is normal.

[0024] Furthermore, the servo control card acquires the input disconnection detection function of the command input circuit, the LVDT feedback circuit, and the disconnection detection function of the servo output. When the above faults are detected, the servo control card switches to the fault card, and the DO channel controls the relay to output an alarm signal, and uses the hardware circuit to shut off the servo output current of the fault card to prevent the servo valve from being damaged.

[0025] 1. In Figure 1 In the case of a dual card working normally, the first servo control card 1 and the second servo control card 5 receive a given command input signal, a LVDT feedback signal of a system device, and a valve core feedback signal of the first servo valve 2 and the second servo valve 4 respectively, and after being processed by the internal microprocessor algorithm, two servo output currents are respectively given to the coils A and B of the servo valve. The servo controller realizes dual-card dual-valve control.

[0026] 2. In Figure 1 In the example, if the first servo control card 1 fails, the servo output current of the first servo control card 1 is turned off, and the second servo control card 5 controls the servo output current to the coil A of the second servo valve 4 and the coil B of the first servo valve 2 to work. Similarly, if the second servo control card 5 fails, the servo output current of the second servo control card 5 is turned off, and the first servo control card 1 controls the coil A of the first servo valve 2 and the coil B of the second servo valve 4 to work. The servo controller realizes single-card dual-valve control.

[0027] 3. In Figure 1 In the example, if the first servo valve 2 fails, the first servo control card 1 shuts off the first solenoid valve 31 and the second solenoid valve 32, and the first servo control card 1 and the second servo control card 5 simultaneously control the second servo valve 4 to work. Similarly, if the second solenoid valve 32 fails, the second servo control card 5 shuts off the third solenoid valve 33 and the fourth solenoid valve 34, and the first servo control card 1 and the second servo control card 5 simultaneously control the first servo valve 2 to work. The servo controller realizes dual-card single-valve control.

[0028] 4. In Figure 1In the example, the first servo control card 1 and the second servo valve 4 fail at the same time: the first servo control card 1 fails, the servo output current of the first servo control card 1 is turned off, and the coil A of the first servo valve 2 and the coil B of the second servo valve 4 have no current; the second servo valve 4 fails, and the second servo control card 5 turns off the third solenoid valve 33 and the fourth solenoid valve 34. At this time, the second servo control card 5 controls the coil B of the first servo valve 2 to work. Similarly, the second servo control card 5 and the first servo valve 2 fail at the same time: the first servo control card 1 controls the coil B of the second servo valve 4 to work. The servo controller realizes single-card single-valve control.

[0029] The test system was built to conduct multiple tests to simulate the failure of the servo control card or servo valve. The servo controller can control the steam turbine equipment to achieve normal operation. The test proves that the designed dual-card dual-control servo controller is effective and reliable.

[0030] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work or software programming. Therefore, any technical solution that can be obtained by a person skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A control method for a dual-card dual-control servo control system with redundant function, characterized in that: The control system comprises: two servo control cards, two output ends of the two servo control cards are respectively connected to a servo valve, and the two servo valves are respectively connected to system equipment; the two servo control cards each comprise: a command input signal end, an LVDT feedback signal end connected to the system equipment, and a servo valve core feedback signal end connected to the corresponding servo valve; The two servo control cards each include a first servo output terminal and a second servo output terminal, and the two servo valves each include: a first coil and a second coil, the first servo output terminal of any one of the servo control cards is connected to the first coil of the corresponding servo valve, and the second servo output terminal of any one of the servo control cards is connected to the second coil of the other servo valve; The two servo control cards communicate through UART port cross wiring; the two servo control cards receive command input signals, LVDT feedback signals, and servo valve core feedback signals, and the servo control card is adjusted by a PID algorithm to give a servo output current, and gives a current output display indicating the current valve position, as well as a current output display of the servo output; the internal microprocessor of the servo control card outputs a corresponding LED working status indication according to whether RXD reception is normal; the servo control card obtains input open circuit detection of the command input circuit, the LVDT feedback circuit, and the open circuit detection function of the servo output. When a fault is detected, the servo control card switches to a fault card, and the DO channel controls the relay to output an alarm signal, and the hardware circuit is used to shut down the servo output current of the fault card to prevent the servo valve from being damaged.

2. The control method of the dual-card dual-control servo control system with redundant function according to claim 1, characterized in that: Two electromagnetic valves are respectively connected between the two servo valves and the system equipment, and the control ends of the two electromagnetic valves are connected to the corresponding servo control cards.

3. The control method of the dual-card dual-control servo control system with redundant function according to claim 1, characterized in that: The two servo control cards both include: a TXD interface and a RXD interface, and the TXD interface of any one of the servo control cards is connected to the RXD interface of the other servo control card.

4. The control method of the dual-card dual-control servo control system with redundant function according to claim 1, characterized in that: The two servo control cards both include: a valve position display port, a servo output display port, a DO alarm indication port, and an LED indication port.

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