A gas turbine electro-hydraulic servo system and its small disturbance switching control method

Abstract

The present invention discloses an electro-hydraulic servo system based on a gas turbine and a small disturbance switching control method thereof. The electro-hydraulic servo system includes a main control servo valve assembly, a backup servo valve assembly, and an oil motor. The main control servo valve assembly includes a main control servo valve and two shut-off solenoid valves, and the backup servo valve assembly includes a backup servo valve and two switching solenoid valves. The main control servo valve and the backup servo valve each have two coils that are redundant with each other. The control system can perform fault identification through displacement and pressure value change rate. When a single coil of the main control servo valve fails, the backup coil can be quickly switched to continue working; when the main control servo valve fails, the backup servo valve can be quickly switched to compensate, and the faulty oil circuit can be cut off at the same time, to ensure that the system responds quickly and stably to the ideal output. Based on the traditional cold backup redundancy, the present invention adopts a hot backup and redundancy switching control scheme, with small redundancy switching fluctuations and low latency, and high reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of servo control, and relates to a hydraulic actuator of a gas turbine IGV, a fuel valve and an anti-surge bleed valve, and in particular to a gas turbine electro-hydraulic servo system and a small disturbance switching control method thereof. Background Art

[0002] At present, gas turbines have increasingly higher requirements for the reliability of their hydraulic actuators. As a key component of the gas turbine electro-hydraulic servo system, the electro-hydraulic servo valve is prone to coil disconnection, disturbance, valve core jamming and other faults during operation. In order to improve its reliability, the cold backup redundancy configuration scheme is currently adopted. Since switching the cold backup channel increases the time for the electro-hydraulic servo valve to switch from the closed state to the energized open state, as well as the time from the valve core opening to the output oil to the pipeline, this scheme has technical problems such as large fluctuations and large delays in redundancy switching, and is prone to hazardous faults such as machine tripping, which seriously threatens the safe operation of the gas turbine. Summary of the invention

[0003] (1) Technical problem to be solved by the invention

[0004] In view of the above defects and deficiencies of the prior art, the present invention aims to provide a gas turbine electro-hydraulic servo system and a small disturbance switching control method thereof, which can distinguish faults through displacement and pressure value change rate. When a single coil of the main control servo valve fails, the backup coil can be quickly switched to continue working; when the main control servo valve fails, the backup servo valve can be quickly switched to compensate, and the faulty oil circuit can be cut off at the same time to ensure that the system responds quickly and stably to the ideal output. Based on the traditional cold backup redundancy, the present invention adopts a hot backup and redundancy switching control scheme, which has small redundancy switching fluctuations, low delay, and high reliability.

[0005] (II) The technical solution adopted by the present invention is:

[0006] A gas turbine electro-hydraulic servo system comprises at least a main control servo valve assembly, a backup servo valve assembly, and an oil motor, and is characterized in that:

[0007] The main control servo valve assembly includes a main control servo valve and two shut-off solenoid valves.

[0008] The backup servo valve assembly includes a backup servo valve and two switching solenoid valves.

[0009] The main control servo valve and the backup servo valve are each provided with two mutually redundant coils.

[0010] The hydraulic motor is provided with two displacement sensors for monitoring the movement of the piston rod.

[0011] The P ports of the main control servo valve and the backup servo valve are connected to the constant pressure oil source through the main oil supply pipeline, and the T ports are connected to the return oil pipeline through the oil circuit, and a first oil pressure sensor is provided on the main oil supply pipeline.

[0012] The A port of the main control servo valve is connected to the rodless chamber of the oil motor through the oil circuit via the first shut-off solenoid valve, and the B port is connected to the rod chamber of the oil motor through the oil circuit via the second shut-off solenoid valve, and a second oil pressure sensor is provided on the oil circuit between the first shut-off solenoid valve and the rodless chamber of the oil motor, and a third oil pressure sensor is provided on the oil circuit between the second shut-off solenoid valve and the rod chamber of the oil motor.

[0013] The A port of the backup servo valve is connected to the rodless chamber of the oil motor through the oil circuit in sequence through the P port and the A port of the first switching solenoid valve. The B port of the backup servo valve is connected to the rod chamber of the oil motor through the oil circuit in sequence through the P port and the A port of the second switching solenoid valve. The T ports of the first switching solenoid valve and the second switching solenoid valve are both connected to the return oil pipeline through the oil circuit.

[0014] The main control servo valve assembly and its oil circuit form a main control channel.

[0015] The backup servo valve assembly and its oil circuit form a backup channel.

[0016] Preferably, a constant pressure variable displacement piston pump is provided on the main oil supply pipeline, which can adjust the flow rate according to the load to ensure that the pressure of the electro-hydraulic servo system will not continue to increase when a certain link is blocked.

[0017] Furthermore, an accumulator is provided in the constant pressure oil source to ensure that the oil pressure supplied to the electro-hydraulic servo system is constant.

[0018] Preferably, when the electro-hydraulic servo system is working normally, the first coil of the main control servo valve is energized and the second coil is de-energized, the first coil of the backup servo valve is energized and the second coil is de-energized, the two shut-off solenoid valves and the two switching solenoid valves are all de-energized, and the hydraulic oil output through the main control channel directly enters the rodless chamber and the rod chamber of the oil motor to control its piston movement, while the hydraulic oil output through the backup channel waits at the entrance of the two switching solenoid valves, and the oil circuit between the oil motor and the two switching solenoid valves is filled with hydraulic oil to ensure that the main control channel can be quickly compensated during switching.

[0019] Preferably, when a certain coil of the main control servo valve fails, after fault identification is performed based on the displacement change rate of the displacement sensor provided on the oil motor, the main control servo valve is quickly switched to another coil to continue working. Meanwhile, during the switching process, the oil volume is macro-controlled by energizing the two switching solenoid valves.

[0020] Further, according to the first-order displacement change rate of the displacement sensor and / or second-order displacement rate of change It is determined whether a coil failure occurs in the main control servo valve, wherein X is the displacement signal collected by the displacement sensor.

[0021] Preferably, the two displacement sensors are mutually redundant. To avoid abnormal feedback signals of one of the displacement sensors, the feedback signals of the two displacement sensors are calculated in the controller. 1 -X 2 |≥Δ, take max{X 1 , X 2} as feedback value; when |X 1 -X 2 |<Δ, take (X 1 +X 2 ) / 2 as the feedback value, where X 1 is the feedback signal of a displacement sensor, X 2 is the feedback signal of another displacement sensor.

[0022] Preferably, the main servo valve and the backup servo valve work synchronously and have consistent output flow rates. When the main servo valve fails, the fault type is determined by comparing the rate of change of the oil pressure on the two outlet oil lines, port A and port B of the main servo valve, with a set threshold.

[0023] Furthermore, when a disturbance-type fault occurs in the main control servo valve, resulting in insufficient oil supply, flow compensation is performed by controlling the two switching solenoid valves. At this time, the main control channel and the backup channel supply oil to the oil motor at the same time; when an irreversible fault occurs, the oil circuit of the main control channel is cut off by controlling the two shut-off solenoid valves to be energized, and the two switching solenoid valves are energized at the same time. At this time, the backup channel completely takes over the work of the main control channel, quickly outputs oil to the oil motor, and controls its piston to a specified position.

[0024] Another object of the present invention is to provide a small disturbance switching control method for the above-mentioned gas turbine electro-hydraulic servo system, characterized in that:

[0025] When the electro-hydraulic servo system is working normally, the first coil of the main control servo valve is energized and the second coil is de-energized, the first coil of the backup servo valve is energized and the second coil is de-energized, the two shut-off solenoid valves and the two switching solenoid valves are all de-energized, and the hydraulic oil output through the main control channel directly enters the rodless chamber and the rod chamber of the oil motor to control its piston movement, while the hydraulic oil output through the backup channel waits at the entrance of the two switching solenoid valves, and the oil circuit between the oil motor and the two switching solenoid valves is filled with hydraulic oil to ensure that the main control channel can be quickly compensated during switching.

[0026] Preferably, when a certain coil of the main control servo valve fails, after fault identification is performed based on the displacement change rate of the displacement sensor provided on the oil motor, the main control servo valve is quickly switched to another coil to continue working. Meanwhile, during the switching process, the oil volume is macro-controlled by energizing the two switching solenoid valves.

[0027] Further, according to the first-order displacement change rate of the displacement sensor and / or second-order displacement rate of change It is determined whether a coil failure occurs in the main control servo valve, wherein X is the displacement signal collected by the displacement sensor.

[0028] Preferably, the main servo valve and the backup servo valve work synchronously and have consistent output flow rates. When the main servo valve fails, the fault type is determined by comparing the rate of change of the oil pressure on the two outlet oil lines, port A and port B of the main servo valve, with a set threshold.

[0029] Furthermore, when a disturbance-type fault occurs in the main control servo valve, resulting in insufficient oil supply, flow compensation is performed by controlling the two switching solenoid valves. At this time, the main control channel and the backup channel supply oil to the oil motor at the same time; when an irreversible fault occurs, the oil circuit of the main control channel is cut off by controlling the two shut-off solenoid valves to be energized, and the two switching solenoid valves are energized at the same time. At this time, the backup channel completely takes over the work of the main control channel, quickly outputs oil to the oil motor, and controls its piston to a specified position.

[0030] (III) The advantages of the present invention compared with the prior art are:

[0031] The gas turbine based electro-hydraulic servo system and its small disturbance switching control method adopt a hot backup and redundancy switching control scheme, and perform fault identification through displacement and pressure value change rate. When a single coil of the main control servo valve fails, the backup coil can be quickly switched to continue working; when the main control servo valve fails, the backup servo valve can be quickly switched to compensate, and the faulty oil circuit can be cut off at the same time, ensuring that the system responds to the ideal output quickly and stably. The present invention has the technical advantages of small fluctuations in the redundancy switching process, low delay, high reliability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the gas turbine electro-hydraulic servo system of the present invention;

[0033] Figure 2 It is a schematic diagram of a small disturbance switching control method of a gas turbine electro-hydraulic servo system of the present invention.

[0034] The marks in the figure are:

[0035] 1-main control servo valve, 2-backup servo valve, 3-first shut-off solenoid valve, 4-second shut-off solenoid valve, 5-first switching solenoid valve, 6-second switching solenoid valve, 7-oil motor, 8-LVDT displacement sensor, P3, P4, P5-oil pressure sensor. DETAILED DESCRIPTION

[0036] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the following is only a preferred embodiment of the present invention, but the content of the present invention is not limited to the following embodiments. In fact, various modifications and changes can be made in the present invention without departing from the scope or spirit of the present invention, which will be apparent to those skilled in the art. For example, the features shown or described as a part of an embodiment can be used together with another embodiment to produce another embodiment. Therefore, it is intended that the present invention includes such modifications and changes within the scope of the appended claims and their equivalents.

[0037] Figure 1 It is a schematic diagram of the gas turbine electro-hydraulic servo system of the present invention. The electro-hydraulic servo system includes a main control servo valve assembly, a backup servo valve assembly, an oil motor 7, two LVDT displacement sensors 8 and three oil pressure sensors P3, P4, P5. The main control servo valve assembly includes a main control servo valve 1, a first shut-off solenoid valve 3 and a second shut-off solenoid valve 4, and the backup servo valve assembly includes a backup servo valve 2, a first switching solenoid valve 5 and a second switching solenoid valve 6. The main control servo valve 1 and the backup servo valve 2 each have two coils that are redundant to each other. The two coils in the main control servo valve 1 are coil a and coil b, respectively, and the two coils in the backup servo valve 2 are coil c and coil d, respectively.

[0038] The P ports of the main control servo valve 1 and the backup servo valve 2 are connected to the constant pressure oil source through the main oil supply pipeline, and the T ports are connected to the return oil pipeline through the oil circuit, and the main oil supply pipeline is provided with a first oil pressure sensor P3. The first shut-off solenoid valve 3 and the second shut-off solenoid valve 4 are respectively connected to the A and B outlets of the main control electro-hydraulic servo valve 1, and are used to cut off the oil circuit supplied from the main control servo valve 1 to the rodless chamber A and the rod chamber B of the oil motor. The first switching solenoid valve 5 and the second switching solenoid valve 6 are respectively connected to the A and B outlets of the backup electro-hydraulic servo valve 2, and are used to control the on-off of the oil circuit between the outlet of the backup servo valve 2 and the rodless chamber A and the rod chamber B of the oil motor. A second oil pressure sensor P4 is provided on the oil circuit between the first shut-off solenoid valve 3 and the rodless chamber A of the oil motor 7, and a third oil pressure sensor P5 is provided on the oil circuit between the second shut-off solenoid valve 4 and the rod chamber B of the oil motor 7.

[0039] The main control servo valve assembly and its oil circuit form the main control channel, and the backup servo valve assembly and its oil circuit form the backup channel. Both the main control channel and the backup channel are supplied with oil by a constant pressure oil source (such as Figure 1 ), the oil pump uses a constant pressure variable piston pump, which can adjust the flow rate according to the load to ensure that the pressure will not continue to rise when a certain link in the system is blocked. The oil supply system is also equipped with an accumulator to further ensure that the oil pressure supplied to the electro-hydraulic servo system is constant.

[0040] Figure 2 The main control servo valve 1 and the backup servo valve 2 work synchronously, and the output flow is consistent. The error e obtained by comparing the input position command r with the feedback value of the LVDT displacement sensor of the oil motor piston rod position is A , after being calculated by the servo controller, the same current signal I is output A To the master channel and backup channel.

[0041] In particular, the LVDT displacement sensor adopts a redundant configuration. To avoid abnormality in one of the signals, the two signals are operated in the controller. 1 -X 2 |≥Δ, take max{X 1 , X 2} as feedback value; when |X 1 -X 2 |<Δ, take (X 1 +X 2 ) / 2 as the feedback value, where X 1 is the feedback signal of a displacement sensor, X 2 is the feedback signal of another displacement sensor.

[0042] Figure 1 and Figure 2 It shows the status of the system when it is working normally. The coil a of the main servo valve is energized and the coil b is de-energized. The coil c of the hot standby servo valve is energized and the coil d is de-energized. The two shut-off solenoid valves 3 and 4 and the two switching solenoid valves 5 and 6 are all de-energized. The hydraulic oil outputted by the main servo valve 1 directly enters the left and right chambers of the oil motor 7 to control its piston movement, while the hydraulic oil outputted by the backup servo valve 2 waits at the inlet of the switching solenoid valves 5 and 6. The pipeline between the oil motor 7 and the switching solenoid valves 5 and 6 is filled with hydraulic oil, which can be quickly compensated during switching.

[0043] When the coil of the main control servo valve 1 fails, such as coil a is open or short-circuited, the displacement change rate of the oil motor LVDT displacement sensor After the fault is identified, the b coil is quickly switched to continue working. At the same time, during the switching process, the oil volume is macro-controlled by energizing the switching solenoid valves 5 and 6.

[0044] When the main control servo valve 1 fails, the outlet oil pressure P 4 , P 5 Rate of change With the set threshold δ 1 , δ 2 , 1 , 2 Determine the fault type.

[0045] If a disturbance fault occurs in the main control servo valve 1, resulting in insufficient oil supply, flow compensation is performed by controlling the switching solenoid valves 5 and 6. At this time, the main control channel and the backup channel supply oil to the oil motor at the same time; if an irreversible fault such as valve core sticking or nozzle clogging occurs in the main control servo valve 1, the solenoid valves 3 and 4 are controlled to be energized, the main control channel oil circuit is cut off, the faulty oil circuit is removed, and the solenoid valves 5 and 6 are switched on at the same time. At this time, the backup channel completely takes over the work of the main control channel, quickly outputs oil to the oil motor 7, and controls its piston to the specified position.

[0046] Through the above embodiments, the purpose of the present invention is fully and effectively achieved. Any equivalent or simple changes made according to the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. The technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all belong to the protection scope of the present invention.

[0047] The present invention does not elaborate on some of the well-known technologies that belong to those skilled in the art.

Claims

1. A gas turbine electro-hydraulic servo system, comprising at least a main control servo valve assembly, a backup servo valve assembly, and an oil motor, characterized in that: The main control servo valve assembly includes a main control servo valve and two shut-off solenoid valves. The backup servo valve assembly includes a backup servo valve and two switching solenoid valves. The main control servo valve and the backup servo valve are each provided with two mutually redundant coils. The hydraulic motor is provided with two displacement sensors for monitoring the movement of the piston rod. The P ports of the main control servo valve and the backup servo valve are connected to the constant pressure oil source through the main oil supply pipeline, and the T ports are connected to the return oil pipeline through the oil circuit, and a first oil pressure sensor is provided on the main oil supply pipeline. The A port of the main control servo valve is connected to the rodless chamber of the oil motor through the oil circuit via the first shut-off solenoid valve, and the B port is connected to the rod chamber of the oil motor through the oil circuit via the second shut-off solenoid valve, and a second oil pressure sensor is provided on the oil circuit between the first shut-off solenoid valve and the rodless chamber of the oil motor, and a third oil pressure sensor is provided on the oil circuit between the second shut-off solenoid valve and the rod chamber of the oil motor. The A port of the backup servo valve is connected to the rodless chamber of the oil motor through the oil circuit in sequence through the P port and the A port of the first switching solenoid valve. The B port of the backup servo valve is connected to the rod chamber of the oil motor through the oil circuit in sequence through the P port and the A port of the second switching solenoid valve. The T ports of the first switching solenoid valve and the second switching solenoid valve are both connected to the return oil pipeline through the oil circuit. The main control servo valve assembly and its oil circuit form a main control channel. The backup servo valve assembly and its oil circuit form a backup channel; Among them, when the electro-hydraulic servo system is working normally, the first coil of the main control servo valve is energized and the second coil is de-energized, the first coil of the backup servo valve is energized and the second coil is de-energized, the two shut-off solenoid valves and the two switching solenoid valves are all de-energized, and the hydraulic oil output through the main control channel directly enters the rodless chamber and the rod chamber of the oil motor to control its piston movement, while the hydraulic oil output through the backup channel waits at the entrance of the two switching solenoid valves, and the oil circuit between the oil motor and the two switching solenoid valves is filled with hydraulic oil to ensure that the main control channel can be quickly compensated during switching.

2. The gas turbine electro-hydraulic servo system according to claim 1, characterized in that: The oil pump of the constant pressure oil source is a constant pressure variable piston pump, which can adjust the flow rate according to the load to ensure that the pressure of the electro-hydraulic servo system will not continue to rise when a certain link is blocked. An accumulator is also provided in the constant pressure oil source to ensure that the oil pressure supplied to the electro-hydraulic servo system is constant.

3. The gas turbine electro-hydraulic servo system according to claim 1, characterized in that: When a certain coil of the main control servo valve fails, after the fault is identified according to the displacement change rate of the displacement sensor arranged on the oil motor, the main control servo valve is quickly switched to another coil to continue working. At the same time, during the switching process, the oil volume is macro-controlled by energizing the two switching solenoid valves.

4. The gas turbine electro-hydraulic servo system according to claim 3, characterized in that: According to the first-order displacement change rate of the displacement sensor and / or second-order displacement rate of change It is determined whether the main control servo valve has a coil failure, wherein: X It is the displacement signal collected by the displacement sensor.

5. The gas turbine electro-hydraulic servo system according to claim 1, characterized in that: The two displacement sensors are redundant. To avoid abnormal feedback signals from one of the displacement sensors, the feedback signals from the two displacement sensors are calculated in the controller. When As feedback value; When As the feedback value, X 1 is the feedback signal of a displacement sensor, X 2 is the feedback signal of another displacement sensor.

6. The gas turbine electro-hydraulic servo system according to claim 1, characterized in that: The main control servo valve and the backup servo valve work synchronously and have the same output flow. When the main control servo valve fails, the fault type is determined by the change rate of the oil pressure on the two outlet oil lines of port A and port B of the main control servo valve and the set threshold.

7. The gas turbine electro-hydraulic servo system according to claim 6, characterized in that: When a disturbance-type fault occurs in the main control servo valve, resulting in insufficient oil supply, flow compensation is performed by controlling the two switching solenoid valves. At this time, the main control channel and the backup channel supply oil to the oil motor at the same time; when an irreversible fault occurs, the oil circuit of the main control channel is cut off by controlling the two shut-off solenoid valves to be energized, and the two switching solenoid valves are energized at the same time. At this time, the backup channel completely takes over the work of the main control channel, quickly outputs oil to the oil motor, and controls its piston to the specified position.

8. A small disturbance switching control method for a gas turbine electro-hydraulic servo system according to any one of claims 1 to 7, characterized in that: When the electro-hydraulic servo system is working normally, the first coil of the main control servo valve is energized and the second coil is de-energized, the first coil of the backup servo valve is energized and the second coil is de-energized, the two shut-off solenoid valves and the two switching solenoid valves are all de-energized, and the hydraulic oil output through the main control channel directly enters the rodless chamber and the rod chamber of the oil motor to control its piston movement, while the hydraulic oil output through the backup channel waits at the entrance of the two switching solenoid valves, and the oil circuit between the oil motor and the two switching solenoid valves is filled with hydraulic oil to ensure that the main control channel can be quickly compensated during switching.

9. The small disturbance switching control method according to claim 8, characterized in that: When a certain coil of the main control servo valve fails, after the fault is identified according to the displacement change rate of the displacement sensor arranged on the oil motor, the main control servo valve is quickly switched to another coil to continue working. At the same time, during the switching process, the oil volume is macro-controlled by energizing the two switching solenoid valves.

10. The small disturbance switching control method according to claim 9, characterized in that: According to the first-order displacement change rate of the displacement sensor and / or second-order displacement rate of change It is determined whether the main control servo valve has a coil failure, wherein: X It is the displacement signal collected by the displacement sensor.

11. The small disturbance switching control method according to claim 8, characterized in that: The main control servo valve and the backup servo valve work synchronously and have the same output flow. When the main control servo valve fails, the fault type is determined by the change rate of the oil pressure on the two outlet oil lines of port A and port B of the main control servo valve and the set threshold.

12. The small disturbance switching control method according to claim 11, characterized in that: When a disturbance-type fault occurs in the main control servo valve, resulting in insufficient oil supply, flow compensation is performed by controlling the two switching solenoid valves. At this time, the main control channel and the backup channel supply oil to the oil motor at the same time; when an irreversible fault occurs, the oil circuit of the main control channel is cut off by controlling the two shut-off solenoid valves to be energized, and the two switching solenoid valves are energized at the same time. At this time, the backup channel completely takes over the work of the main control channel, quickly outputs oil to the oil motor, and controls its piston to the specified position.

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