Control device and equipment for static frequency converter of gas turbine

Abstract

The utility model provides a control device and equipment for a gas turbine static frequency converter, and relates to the technical field of gas turbine static frequency converters. The device comprises a start-stop loop and a gas turbine protection loop which are connected in parallel, and an emergency stop unit connected with the gas turbine protection loop, the start-stop loop comprises a normal start relay and a normal stop relay which are sequentially connected in series; the gas turbine protection loop comprises a high disc mode relay and a gas turbine protection unit which are sequentially connected in series; the emergency stop unit comprises an emergency stop relay; an emergency stop coil of the emergency stop relay is connected in series in a gas turbine protection loop; a contact of the emergency stop relay is connected with the static frequency converter. The utility model can solve the problem of potential safety hazards caused by misjudgment of the static frequency converter of the gas turbine.

Description

Technical Field

[0001] This utility model relates to the technical field of static frequency converters for gas turbines, and in particular to a control device and equipment for a static frequency converter for gas turbines. Background Technology

[0002] A combined cycle gas turbine (GC) power unit is a highly efficient power generation device that organically combines gas turbine and steam turbine cycles to achieve higher energy utilization efficiency and power generation benefits. The unit consists of a gas turbine (hereinafter referred to as the gas turbine) and a steam turbine (hereinafter referred to as the steam turbine). The gas turbine's SFC (Static Frequency Converter) is a power electronic power supply device that can provide simultaneous frequency and voltage variations. In the gas turbine, the SFC acts as a starting device, providing alternating power to the stator side of the generator, driving the gas turbine to accelerate to its self-sustaining speed. During the unit startup phase, the SFC device supplies power to the generator, transforming the generator into a synchronous motor. For example, the entire unit startup process can be roughly divided into: the SFC device drives the unit to a certain speed; the gas turbine performs purging and cleaning of the combustion system, ignition, and acceleration after ignition; under the combined action of the gas turbine and the SFC device, the unit accelerates to a self-sustaining speed of 2000 rpm, after which the SFC device disengages; finally, the unit self-sustains and accelerates to the rated speed of 3000 rpm. The SFC control device is the control device that controls the SFC to perform the above-mentioned working process.

[0003] Existing SFC control devices include start-stop circuits. These start-stop circuits are typically hard-circuit, including a normal stop relay. The on / off state of the start-stop circuit serves as the signal source for controlling the SFC. When the normal stop relay is disconnected, the start-stop circuit loses power, simultaneously issuing both a normal stop command and an emergency stop command, which the SFC then distinguishes between. However, the SFC and its control device may be manufactured by different companies. When receiving two commands simultaneously, SFCs from different manufacturers may prioritize the emergency stop command. This can cause the control device to misinterpret a normal stop command as an emergency stop command. For example, in 700 rpm high-disk mode, if the operator manually operates a normal stop to stop the SFC, the start-stop circuit disconnects and loses power, simultaneously issuing both normal and emergency stop commands. The SFC prioritizes the emergency stop command. During the execution of the emergency stop command, the moving and stationary contacts of the generator's excitation / de-excitation switch will be burned and damaged, significantly reducing their lifespan and potentially causing generator damage, posing a safety hazard. Utility Model Content

[0004] This utility model provides a control device and equipment for a gas turbine static frequency converter to solve the safety hazard problem caused by misjudgment of the gas turbine static frequency converter.

[0005] In a first aspect, embodiments of this utility model provide a control device for a gas turbine static frequency converter. The control device is used to control the static frequency converter. The control device includes: a start-stop circuit and a gas turbine protection circuit connected in parallel, and an emergency stop unit connected to the gas turbine protection circuit. The start-stop circuit includes a normal start relay and a normal stop relay connected in series. The gas turbine protection circuit includes a high-disk mode relay and a gas turbine protection unit connected in series. The emergency stop unit includes an emergency stop relay. The emergency stop coil of the emergency stop relay is connected in series in the gas turbine protection circuit. The contacts of the emergency stop relay are connected to the static frequency converter.

[0006] In one possible implementation, the start-stop circuit further includes a start-locking relay; the contacts of the start-locking relay are connected in parallel with the contacts of the normal start relay; and the coil of the start-locking relay is connected in series in the start-stop circuit after the contacts of the normal stop relay.

[0007] In one possible implementation, the normal start relay and the start self-locking relay are normally open relays; the normal stop relay is a normally closed relay.

[0008] In one possible implementation, the start-stop circuit further includes a gas turbine protection relay; the contacts of the gas turbine protection relay are connected in series in the start-stop circuit; the coil of the gas turbine protection relay is connected in series in the gas turbine protection circuit and in parallel with the emergency stop coil.

[0009] In one possible implementation, the gas turbine protection relay is a normally open relay.

[0010] In one possible implementation, the gas turbine protection unit includes: a gas turbine main protection relay, an overspeed protection relay, and an emergency stop button relay.

[0011] In one possible implementation, the control device further includes a turbine protection circuit; the turbine protection circuit includes a turbine protection unit; the gas turbine protection circuit further includes a turbine protection relay; the contacts of the turbine protection relay are connected in parallel with the contacts of the high-disk mode relay; and the coil of the turbine protection relay is connected in series in the turbine protection circuit.

[0012] In one possible implementation, the turbine protection relay is a normally open relay.

[0013] In one possible implementation, the turbine protection unit includes a gas turbine main protection relay, an overspeed protection relay, an emergency stop button relay, and a turbine trip protection relay.

[0014] Secondly, the present invention provides a control device for a gas turbine static frequency converter, including the control device for a gas turbine static frequency converter as described in any one of the first aspects.

[0015] This utility model provides a control device and equipment for a gas turbine static frequency converter. Through the gas turbine protection circuit, in high-disk mode, the high-disk mode relay is closed. When a gas turbine protection trip condition occurs and the gas turbine protection unit opens, the gas turbine protection circuit is disconnected, and the emergency stop coil is de-energized. The emergency stop coil outputs a de-energization signal to the emergency stop unit, which outputs an emergency stop command to the static frequency converter based on the de-energization signal, thereby achieving emergency shutdown of the gas turbine under the control of the static frequency converter. Additionally, when manually stopping in high-disk mode, the normal stop relay is manually disconnected, and the start-stop circuit is disconnected, achieving normal shutdown. At this time, since the signal source of the emergency stop command has been changed to the gas turbine protection circuit, the start-stop circuit will not issue an emergency stop command during normal shutdown.

[0016] Therefore, by changing the signal source of the emergency stop command from the start-stop circuit to the gas turbine protection circuit, the control device structure of this utility model separates the manual normal stop signal and the emergency stop signal, avoiding misjudgment of the normal stop command manually operated by the operator in high-frequency mode by the static frequency converter, thereby avoiding the burning damage of the moving and stationary contacts of the unit's excitation and demagnetization switch caused by emergency stop, and eliminating the safety hazards caused thereby. Attached Figure Description

[0017] Figure 1 This is an application scenario diagram of a control device for a gas turbine static frequency converter provided in an embodiment of this utility model;

[0018] Figure 2 This is a schematic diagram of the control device for a gas turbine static frequency converter provided in an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0020] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0021] The implementation of this utility model will be described in detail below with reference to the specific accompanying drawings:

[0022] Figure 1 This diagram illustrates an application scenario of a control device for a gas turbine static frequency converter, provided as an embodiment of the present invention. (Refer to...) Figure 1 Control device 1 controls static frequency converter 2; static frequency converter 2 controls gas turbine 3. For example, gas turbine 3 may be one of the main components of a gas-steam combined cycle generator set. The fuel for gas turbine 3 is liquefied natural gas.

[0023] For example, a gas-steam combined cycle generator set may also include a steam turbine.

[0024] For example, a gas-steam combined cycle generator set may also include a DIASYS control system. The DIASYS control system is a control system provided as a complete set with the main equipment, and its controlled equipment scope includes the main equipment and key auxiliary equipment, including the gas turbine, steam turbine, generator and excitation system, lubrication system, control oil system, generator sealing oil system, main steam system, and turbine island power distribution equipment. The DIASYS system can determine the start-up conditions of the entire unit, and can also monitor and regulate the equipment within the above-mentioned control scope, as well as provide trip protection functions. Operators can perform start-up and shutdown operations on the entire unit through the DIASYS system.

[0025] The following explains high-speed turning gear operation for gas turbines. High-speed turning gear, or simply "high-speed turning," is an operating mode where the gas turbine is accelerated to approximately 700 rpm and maintained using a separate SFC (Self-Fueling Control Unit). The functions of high-speed turning gear operation include:

[0026] 1) If ignition fails during the gas turbine startup process, the residual gas in the transition section is discharged through the high plate.

[0027] 2) Before restarting the unit after a long period of shutdown or maintenance, check the starting equipment and the condition of all gas turbine components by using a high-level control panel.

[0028] 3) After the gas turbine is shut down, the components in the combustion chamber and turbine cylinder are at high temperatures. During the cooling process, the different cooling rates can easily lead to excessive temperature differences between them, resulting in uneven deformation. After shutdown, a high plate can be used to evenly cool the components in the hot passage, reducing the temperature difference between the upper and lower cylinder blocks and preparing them for the next startup.

[0029] 4) When washing the gas turbine, a high-speed turning gear is used to enhance the impact of water flow inside the gas turbine, so that the washing effect can be better. After the washing is completed, the gas turbine can be dried by a high-speed turning gear.

[0030] The following explains the problems that occur under high-speed turning gear operation. Normally, the SFC (Self-Controlled Gas Turbine) and its control unit are products from the same manufacturer. However, the SFC and control unit may be manufactured by different companies. For example, the original SFC unit in a power plant was an auxiliary device attached to a heavy-duty gas turbine. Due to actual production needs, the SFC unit was replaced. After the gas turbine high-speed turning gear operation is completed, when the operator issues a stop command, due to the DIASYS control system's control logic and relay hard-circuit design, a STARTING DEVICE OFF REQUEST pulse command (hereinafter referred to as the normal stop command) and an EMERGENCY STOP command (hereinafter referred to as the emergency stop command) will appear. The SFC unit before replacement will execute the normal stop mode, i.e., block the power unit pulse, reduce the excitation current analog quantity adjustment command to 0, and sequentially restore the disconnectors and circuit breakers to their initial states, without triggering a major fault to the generator protection. However, the SFC unit after replacement exhibits the following behavior: upon receiving the normal stop command and the emergency stop command, it directly executes the emergency stop mode, i.e., blocks the power unit pulse, immediately cuts off the excitation, and triggers a major fault to the generator protection. Furthermore, if an SFC device experiences an emergency stop, the operator must go to the site to reset the SFC device before restarting it; otherwise, the unit startup will be blocked, and equipment availability will decrease. Analysis suggests that SFC devices from different manufacturers may prioritize the emergency stop command when receiving two commands simultaneously. For example, a replaced SFC device might execute the emergency stop procedure as soon as it receives an emergency stop command.

[0031] The following explains the SFC stop command control loop. There are three ways for an SFC device to switch from running to stopping:

[0032] 1) After the unit starts normally and accelerates to its self-sustaining speed, the SFC device will automatically stop operating.

[0033] 2) After the unit reaches 700 rpm, the operator manually stops the SFC device.

[0034] 3) During SFC operation, if the gas turbine protection signal is triggered, the SFC device needs to be shut down as soon as possible to protect the equipment, i.e., the SFC device trips urgently.

[0035] In the first method mentioned above, after the unit starts normally, when the speed reaches 2000 rpm, a normal stop command will be issued through the logic control page of the DIASYS control system. After receiving the normal stop command, the SFC device will execute the normal shutdown mode.

[0036] In the second method above, when the unit is running in high panel mode, if the operator believes that the SFC device in high panel mode needs to be taken out of operation, the operator needs to issue a NORMAL STOP command (i.e., normal shutdown command) on the operation screen.

[0037] In the third method mentioned above, during the operation of SFC, the gas turbine protection signal is triggered, and an emergency stop command is issued through the logic control of the DIASYS control system and the hard-wired relay circuit to realize the emergency trip of the SFC device.

[0038] For example, the DIASYS control system is used as an example. In the DIASYS control system, GTSRTRQ represents the unit start command, GTSTPRQ / GTSTPRQX represents the unit stop command, and SPINSEL represents the unit selecting high-level mode.

[0039] HN86GT1X1-X4 represents the DIASYS controller TPS related control logic page definition for gas turbine tripping logic, i.e., gas turbine tripping conditions, including soft logic gas turbine main protection, overspeed, hard circuit emergency stop button, etc.

[0040] HN86GTX1-X4 represents the DIASYS controller TPS-related control logic page definition for gas turbine tripping logic, i.e., all tripping conditions of the unit, including soft logic gas turbine main protection, overspeed, hard circuit emergency stop button, and soft logic steam turbine tripping protection. Steam turbine tripping protection includes low gas pressure, lost flame detector, gas turbine leak, and high boiler water level.

[0041] When no unit trip protection conditions exist, the HN86GTX relay coil is energized, and both the H86GTX and relay coils are energized. When only the turbine trip protection conditions exist, the HN86GT1X1 to HN86GT1X4 contacts close. The operator can also issue SPIN high-level mode commands on the DIASYS control system operation screen, and the H86GTX and relay coils can also be energized. All unit start-up conditions are met.

[0042] Subsequently, when the operator issues the GTSRTRQ unit start command, the coils of HL4X1, HL4X2, and HL4X3 are all energized, and the SFC unit can start operation. When the operator issues the NORMAL STOP command on the operation screen, the GTSRTRQ and GTSRTRQX contacts will be opened via the DIASYS logic control page and hardwiring. At this time, the corresponding HL4X1, HL4X2, and HL4X3 relay coils are de-energized, and the corresponding auxiliary contact signals H-L4-1, H-L4-2, and H-L4-3 are all 0. At this time, both emergency stop and normal stop commands are issued to the SFC.

[0043] In summary, once the operator issues the NORMAL STOP command, HL4X1, HL4X2, and HL4X3 relays will all lose power, indirectly causing HL4X3 relay to lose power. This will trigger an emergency stop command to the SFC device, and the L4 (MASTER ON) signal, which indicates the unit's operating status, will also disappear, while a normal stop command will be issued simultaneously.

[0044] Existing SFC control devices include start-stop circuits. These start-stop circuits are typically hard-wired, including a normal shutdown relay. The on / off state of the start-stop circuit serves as the signal source for controlling the SFC. When the normal shutdown relay is disconnected, the start-stop circuit loses power, simultaneously issuing both a normal shutdown command and an emergency shutdown command, which the SFC then distinguishes between. However, after replacement, the SFC cannot differentiate between these two commands and may misinterpret the normal shutdown command as an emergency shutdown command. In high-level operation mode, the emergency shutdown command generates a blocking power unit pulse, immediately disconnects the excitation, and can even significantly reduce the lifespan of the excitation demagnetization switch contacts.

[0045] Figure 2 This is a schematic diagram of a control device for a gas turbine static frequency converter provided in an embodiment of the present invention. The dashed arrows indicate the connection between the relay and the relay coil. The + / - symbols represent the positive / negative terminals of the power supply; the power supply itself is not shown here. The control device 1 is used to control the static frequency converter 2; see reference... Figure 1 The control device 1 includes: a start-stop circuit and a gas turbine protection circuit connected in parallel, and an emergency stop unit 15 connected to the gas turbine protection circuit; the start-stop circuit includes a normal start relay 11 and a normal stop relay 12 connected in series; the gas turbine protection circuit includes a high-disk mode relay 13 and a gas turbine protection unit 14 connected in series; the emergency stop unit 15 includes an emergency stop relay; the emergency stop coil of the emergency stop relay is connected in series in the gas turbine protection circuit; the contacts of the emergency stop relay are connected to the static frequency converter 2.

[0046] In some embodiments, when the high-disk mode relay 13 is closed and the gas turbine protection unit 14 is open, the gas turbine protection circuit is disconnected, the emergency stop coil outputs a power-off signal to the emergency stop unit 15, and the emergency stop unit 15 outputs an emergency stop command to the static frequency converter 2 based on the power-off signal.

[0047] For example, when the gas turbine protection unit 14 is disconnected, the gas turbine protection circuit is disconnected. The gas turbine protection circuit is de-energized, and the emergency stop coil is de-energized. When the emergency stop coil is de-energized, the emergency stop relay operates, outputting an emergency stop command to the connected static frequency converter 2.

[0048] In some embodiments, the control device 1 includes: a start-stop circuit and a gas turbine protection circuit connected in parallel, and an emergency stop unit 15 connected to the gas turbine protection circuit.

[0049] For example, the start-stop circuit and the gas turbine protection circuit are connected in parallel. In electrical or control systems, a circuit represents a closed path. For instance, one end of the circuit is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal.

[0050] For example, the start-stop circuit is used for the start-up and shutdown process control of the gas turbine 3. The start-stop circuit and the gas turbine protection circuit are connected in parallel, so that the two independent paths work together to control the gas turbine 3.

[0051] For example, the gas turbine protection circuit monitors the operating status parameters of the gas turbine 3 in real time. When a parameter is detected to be outside the normal range or an abnormal situation occurs, the gas turbine protection circuit will quickly take corresponding protective measures to prevent damage to the gas turbine 3.

[0052] For example, the emergency stop unit 15 is used to output an emergency stop command to the static frequency converter 2. The static frequency converter 2 controls the gas turbine 3 to shut down in an emergency according to the emergency stop command. The emergency stop unit 15 is connected to the gas turbine protection circuit, and the specific connection method will be described in detail later. The structure of the start-stop circuit is described below.

[0053] In some embodiments, the start-stop circuit includes a normal start relay 11 and a normal stop relay 12 connected in series.

[0054] For example, the series structure means that the entire start-stop circuit can only be properly connected when both the contacts of the normal start relay 11 and the contacts of the normal stop relay 12 are closed.

[0055] In some embodiments, the start-stop circuit further includes a start-locking relay 16; the contacts of the start-locking relay 16 are connected in parallel with the contacts of the normal start relay 11; the coil 161 of the start-locking relay is connected in series in the start-stop circuit after the contacts of the normal stop relay 12.

[0056] For example, the normal start relay 11 and the start self-locking relay 16 are connected in parallel. The parallel structure allows them to operate independently in the circuit. When the unit needs to be started, the start signal can be directly triggered by the normal start relay 11, and after starting, the start self-locking function can be achieved by using the start self-locking relay contact 16.

[0057] It should be noted that the self-locking relay 16 can maintain its energized state after the unit starts, thereby ensuring that the start signal remains valid and maintaining the operation of the unit. Even if the initial triggering condition of the start signal disappears, the self-locking relay 16 can continue to be connected through its own self-locking function, providing the current or signal required for the unit to start, and ensuring the stable operation of the unit.

[0058] For example, the coil 161 of the self-locking relay is connected in series in the start-stop circuit after the normal shutdown relay 12. The normal shutdown relay 12 controls the normal shutdown process in the circuit. When the normal shutdown relay 12 operates, it disconnects the coil 161 of the self-locking relay, thereby de-energizing the self-locking relay 16, releasing its self-locking state, and stopping the unit's operation. This ensures that the start signal can be reliably cut off during normal shutdown operations, allowing the unit to shut down safely. Simultaneously, during normal unit operation, the normal shutdown relay 12 is in a non-operating state, not affecting the normal operation of the self-locking relay 16, ensuring stable unit operation.

[0059] In this embodiment of the invention, when the machine is manually stopped in high-disk mode, the normal stop relay 12 is manually disconnected, the coil of the start self-locking relay 16 connected in series in the circuit is de-energized, the start self-locking relay 16 is disconnected, thereby realizing the disconnection of the start-stop circuit and realizing normal stop.

[0060] For example, the normal start relay 11 and the start self-locking relay 16 are normally open relays; the normal stop relay 12 is a normally closed relay.

[0061] In electrical control, normally open relays and normally closed relays are defined based on the default state of their contacts when they are not energized.

[0062] Normal start relay 11 is a normally open relay. When not energized, the contacts of normal start relay 11 are in the open state, the circuit is not open, and no start signal is generated. When the unit needs to start, the control circuit energizes normal start relay 11, its coil generates a magnetic field, attracting the armature to actuate, causing the normally open contacts to close, thereby connecting the start circuit, sending a start signal to gas turbine 3, and triggering a series of start operations.

[0063] The self-locking relay 16 is a normally open relay. In its initial state, the normally open contact of the self-locking relay 16 is also open. During unit startup, after the normal starting relay 11 activates and starts the unit, the self-locking relay 16 receives an energizing signal through its coil connected in series in the start-stop circuit, and its normally open contact closes. Furthermore, even if the original starting signal for the unit disappears (e.g., the start button is released), because the contacts of the self-locking relay 16 are already closed, it maintains its energized state, continuously providing a path to the starting circuit, maintaining the start-up and operation of the gas turbine 3, achieving the "self-locking" function, and ensuring that the unit can stably enter normal operating condition.

[0064] Normal shutdown relay 12 is a normally closed relay. When not energized, the contacts of normal shutdown relay 12 are closed. During normal unit operation, the circuit containing normal shutdown relay 12 is conductive and will not affect the normal operation of the unit. When a normal shutdown is required, the control circuit energizes normal shutdown relay 12, and its coil generates a magnetic field, causing the normally closed contacts to open. Since the coil 161 of the starting self-locking relay is connected in series with normal shutdown relay 12, after the contacts of normal shutdown relay 12 open, the circuit of coil 161 of the starting self-locking relay is cut off, the starting self-locking relay 16 is de-energized, and its normally open contacts open, thereby cutting off the starting circuit, stopping the sending of starting signals to gas turbine 3, and thus causing gas turbine 3 to gradually stop operating according to a predetermined program, completing the normal shutdown process.

[0065] In some embodiments, the gas turbine protection circuit includes a high-disk mode relay 13 and a gas turbine protection unit 14 connected in series. The series structure means that the entire gas turbine protection circuit can only be normally connected when both the high-disk mode relay 13 and the gas turbine protection unit 14 are normally connected.

[0066] The function of the high-disk mode relay 13 in the gas turbine protection circuit is that when the gas turbine 3 is in high-disk mode, the relay will be triggered and its contacts will close, or the gas turbine protection conditions will not exist, thereby connecting the power supply to the gas turbine protection circuit and putting the entire circuit into standby mode.

[0067] For example, the high-disk mode relay 13 is a normally open relay.

[0068] The gas turbine protection unit 14 is the core component of the gas turbine protection circuit. It contains a series of sensors and judgment logic circuits for monitoring various operating parameters of the gas turbine 3. For example, the activation of the gas turbine protection unit 14 indicates that the gas turbine 3 is normal and the protection trip condition has not been triggered.

[0069] For example, the gas turbine protection unit 14 includes: a gas turbine main protection relay, an overspeed protection relay, and an emergency stop button relay.

[0070] In some embodiments, the emergency stop unit 15 includes an emergency stop relay; the emergency stop coil of the emergency stop relay is connected in series in the gas turbine protection circuit; and the contacts of the emergency stop relay are connected to the static frequency converter 2.

[0071] The emergency stop coil is the actuator of the gas turbine protection circuit. For example, when the gas turbine protection unit 14 detects an abnormality in the gas turbine 3 and outputs a trigger signal, the gas turbine protection unit 14 disconnects, and the emergency stop coil is de-energized.

[0072] The following describes the process of generating an emergency stop command in emergency stop unit 15.

[0073] In some embodiments, the emergency stop coil is connected to the emergency stop unit 15. When the high-disk mode relay 13 is closed and the gas turbine protection unit 14 is open, the gas turbine protection circuit is disconnected. The emergency stop coil outputs a power-off signal to the emergency stop unit 15, and the emergency stop unit 15 outputs an emergency stop command to the static frequency converter 2 based on the power-off signal.

[0074] The emergency stop coil transmits its status signal to the emergency stop unit 15, allowing the unit to determine whether to perform an emergency shutdown operation. The closure of the high-disk mode relay 13 indicates that the gas turbine 3 is in high-disk mode, at which point the power supply to the gas turbine protection circuit can be connected, and the circuit can operate normally. When the gas turbine protection unit 14 is disconnected, the entire gas turbine protection circuit is disconnected. Because the gas turbine protection circuit is disconnected, the emergency stop coil loses power, thus outputting a power-down signal. This power-down signal is a critical control signal, indicating that the gas turbine 3 has encountered an abnormal situation requiring an emergency shutdown. By outputting the power-down signal to the emergency stop unit 15, the emergency stop coil conveys the information that the gas turbine 3 needs to be shut down immediately. After receiving the power-down signal from the emergency stop coil, the emergency stop unit 15 processes it according to a preset program and logic, and outputs an emergency shutdown command to the static frequency converter 2. The static frequency converter 2 controls the emergency shutdown of the gas turbine 3.

[0075] This utility model embodiment provides a control device for a gas turbine static frequency converter. Through the gas turbine protection circuit, in high-disk mode, the high-disk mode relay 13 is closed. When a gas turbine protection trip condition occurs and the gas turbine protection unit 14 is disconnected, the gas turbine protection circuit is disconnected, and the emergency stop coil is de-energized. The emergency stop coil outputs a de-energization signal to the emergency stop unit 15, which outputs an emergency stop command to the static frequency converter 2 based on the de-energization signal, thereby achieving an emergency stop of the gas turbine 3 under the control of the static frequency converter 2. Additionally, when manually stopping in high-disk mode, the normal stop relay 12 is manually disconnected, the start-stop circuit is disconnected, and a normal stop is achieved. At this time, since the signal source of the emergency stop command has been changed to the gas turbine protection circuit, the start-stop circuit will not issue an emergency stop command during normal stop.

[0076] Therefore, by changing the signal source of the emergency stop command from the start-stop circuit to the gas turbine protection circuit, the control device structure of this utility model separates the manual normal stop signal and the emergency stop signal, avoiding misjudgment of the normal stop command manually operated by the operator in high-frequency mode by the static frequency converter, thereby avoiding the burning damage of the moving and stationary contacts of the unit's excitation and demagnetization switch caused by emergency stop, and eliminating the safety hazards caused thereby.

[0077] In one possible implementation, the start-stop circuit further includes a gas turbine protection relay 17; the contacts of the gas turbine protection relay 17 are connected in series in the start-stop circuit; the coil 171 of the gas turbine protection relay is connected in series in the gas turbine protection circuit and in parallel with the emergency stop coil.

[0078] For example, the moving contact of the gas turbine protection relay 17 is connected to the stationary contact of the normal start relay 11, and the stationary contact of the gas turbine protection relay 17 is connected to the negative terminal of the power supply. The moving contact of the normal start relay 11 is connected to the positive terminal of the power supply.

[0079] For example, the gas turbine protection relay 17 is a normally open relay.

[0080] In one possible implementation, the control device 1 further includes a turbine protection circuit; the turbine protection circuit includes a turbine protection unit 19; the gas turbine protection circuit further includes a turbine protection relay 18; the contacts of the turbine protection relay 18 are connected in parallel with the contacts of the high-disk mode relay 13; the coil 181 of the turbine protection relay is connected in series in the turbine protection circuit.

[0081] In the gas turbine protection circuit, the turbine protection relay 18 and the high-disk mode relay 13 are connected in parallel. The high-disk mode relay 13 is mainly used to determine whether the gas turbine 3 is in high-disk mode, and thus decide whether the gas turbine protection circuit is activated. The turbine protection relay 18, connected in parallel, can affect the gas turbine protection circuit independently of the state of the high-disk mode relay 13. When the gas turbine protection unit 14 operates, it can directly change the state of the gas turbine protection circuit.

[0082] For example, the turbine protection unit 19 includes a gas turbine main protection relay, an overspeed protection relay, an emergency stop button relay, and a turbine trip protection relay.

[0083] The present invention is illustrated below with a comprehensive embodiment.

[0084] To address the issue where, during operation of the gas turbine's third high-pressure plate, a normal stop command issued by the operator through the DIASYS control system interface causes the GTSTPRQ and GTSTPRQX contacts to open, resulting in the de-energization of HL4X1, HL4X2, and HL4X3 relays. This, in turn, leads to the de-energization of HL4X3 relay, ultimately resulting in an emergency stop command being issued via hardwiring, causing an emergency trip of the SFC unit. Improvements are needed while ensuring the following:

[0085] ①In the first method above, the function of the SFC device automatically exiting operation after the unit starts normally and accelerates to the self-sustaining speed remains unchanged.

[0086] ②In the above-mentioned method 3), the SFC unit trip protection condition control function remains unchanged. When the SFC device is running, if the unit trip protection condition is triggered, an emergency stop command is sent to the SFC device through hard wiring.

[0087] Based on the analysis, the SFC device's "emergency stop" command is optimized as follows: Since the H86GTX relay is the gas turbine trip protection control circuit, the hardwired connection for the SFC emergency trip command, originally controlled by HL4X1, HL4X2, and HL4X3 relays, is changed to the H86GTX relay. Specifically, since the auxiliary contacts of this relay are no longer in use, the new hardwired connection for controlling the SFC emergency stop command can be connected to the newly added TRIP relay auxiliary contacts.

[0088] After the upgrade, when the gas turbine trip protection conditions disappear and the operator selects SPINSEL, or when all unit trip conditions disappear, the emergency stop command for the SFC unit will disappear, and the SFC will be ready to start and operate. When the operator issues a normal stop command on the control screen or after the unit accelerates to its self-sustaining speed, the SFC unit will automatically exit operation; however, when the gas turbine protection conditions are present, the TRIP relay coil will be de-energized, and the SFC unit can still be controlled by the emergency stop command to trip immediately, providing complete control functionality.

[0089] This utility model provides a control device for a gas turbine static frequency converter, including a control device 1 for a gas turbine static frequency converter as described in any of the above claims.

[0090] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A control device for a gas turbine static frequency converter, characterized in that, The control device is used to control the static frequency converter; the control device includes: a start-stop circuit and a gas turbine protection circuit connected in parallel, and an emergency stop unit connected to the gas turbine protection circuit; The start-stop circuit includes a normal start relay and a normal stop relay connected in series. The gas turbine protection circuit includes a high-disc mode relay and a gas turbine protection unit connected in series. The emergency stop unit includes an emergency stop relay; the emergency stop coil of the emergency stop relay is connected in series in the gas turbine protection circuit; the contacts of the emergency stop relay are connected to the static frequency converter.

2. The control device for a gas turbine static frequency converter as described in claim 1, characterized in that, The start / stop circuit also includes a self-locking relay for starting; The contacts of the self-locking relay are connected in parallel with the contacts of the normal start relay; the coil of the self-locking relay is connected in series in the start-stop circuit, after the contacts of the normal stop relay.

3. The control device for a gas turbine static frequency converter as described in claim 2, characterized in that, The normal start relay and the start self-locking relay are normally open relays; The normal shutdown relay is a normally closed relay.

4. The control device for a gas turbine static frequency converter as described in claim 1, characterized in that, The start-stop circuit also includes a gas turbine protection relay; The contacts of the gas turbine protection relay are connected in series in the start-stop circuit; The coil of the gas turbine protection relay is connected in series in the gas turbine protection circuit and in parallel with the emergency stop coil.

5. The control device for a gas turbine static frequency converter as described in claim 4, characterized in that, The gas turbine protection relay is a normally open relay.

6. The control device for a gas turbine static frequency converter as described in claim 1, characterized in that, The gas turbine protection unit includes: a main protection relay for the gas turbine body, an overspeed protection relay, and an emergency stop button relay.

7. The control device for a gas turbine static frequency converter as described in claim 1, characterized in that, The control device also includes a turbine protection circuit; The turbine protection circuit includes a turbine protection unit; The gas turbine protection circuit also includes a turbine protection relay; the contacts of the turbine protection relay are connected in parallel with the contacts of the high-disk mode relay; the coil of the turbine protection relay is connected in series in the turbine protection circuit.

8. The control device for a gas turbine static frequency converter as described in claim 7, characterized in that, The turbine protection relay is a normally open relay.

9. The control device for a gas turbine static frequency converter as described in claim 7, characterized in that, The turbine protection unit includes a main protection relay for the gas turbine body, an overspeed protection relay, an emergency stop button relay, and a turbine trip protection relay.

10. A control device for a gas turbine static frequency converter, characterized in that, The control device includes the gas turbine static frequency converter as described in any one of claims 1 to 9.

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