Accident direct-current oil pump control system of steam turbine generator set

Abstract

The invention discloses a steam turbine generator set accident direct-current oil pump control system and method which are used for solving the problems that a traditional control scheme is low in reliability and delayed in response when a whole plant loses power. The system comprises an operation table button, a pressure switch, a contactor, an intermediate relay, an air switch, a distributed control system (DCS), an emergency button and a conversion button, and is characterized in that four independent starting paths, namely an operation table straight-up path, a field and DCS self-starting path, a DCS remote starting path and a field control cabinet starting path, are arranged. The states of the four paths are mutually exclusive and independent through the conversion buttons SA1 and SA2, and the four paths take effect in parallel. Meanwhile, dual-power protection is configured, and the control loop and the main power loop are respectively connected in series with independent air switches. The multi-redundancy design is adopted, the reliability is remarkably improved, the emergency direct starting path ensures that forced starting can be achieved in a full-fault scene, the structure is simple, and maintenance is convenient.

Description

Technical Field

[0001] This invention relates to the field of generator emergency DC oil pump technology, specifically a generator set emergency DC oil pump control system. It is applicable to preventing bearing burnout accidents caused by bearing oil shortage during a plant-wide power outage. Background Technology

[0002] During the operation of a steam turbine generator set, lubricating oil is typically supplied by an AC oil pump, while a DC emergency oil pump remains in standby mode. When the unit experiences an AC power failure or a main oil pump malfunctions, the DC emergency oil pump must start rapidly to provide lubricating oil to the bearings during an emergency shutdown of the steam turbine, dissipating heat and supplying oil to the turning gear, fixed shaft oil system, regulating system, and safety system to ensure the unit's safety during an emergency shutdown. Maintaining stable bearing lubricating oil pressure is crucial during the operation of the steam turbine generator set. When the main oil pump fails due to a plant-wide power outage, the DC emergency oil pump is the core backup equipment to prevent bearing oil shortage.

[0003] Traditional control schemes mainly rely on two types of methods. The first is the DCS centralized control mode: the low oil pressure signal is processed by the DCS logic to start the oil pump. However, this mode has drawbacks: when the entire plant loses power, the DCS is paralyzed, signal transmission is interrupted, and the oil pump cannot start. In addition, the program scanning cycle is long, which leads to response delay and cannot meet the bearing protection timeliness requirements. The other is the simple hard-wiring mode, where the pressure switch directly triggers the contactor. Although the response is fast, the function is limited, lacking status feedback and remote control capabilities, and there is no emergency manual intervention interface, resulting in insufficient flexibility.

[0004] Publication No. (CN202021637283) discloses a DC oil pump control circuit for generator accidents. This utility model connects the normally open push button switch 1HA and the changeover switch LK1 respectively through the terminal 111 of the DCS start circuit. It uses a common 2-position rotary handle and intermediate relay for connection. One end of the changeover switch LK2 is connected to the normally open delayed closing contact. Other circuits are controlled separately by the DCS control system.

[0005] The aforementioned comparative documents only have a single start control method, lack an emergency operation direct connection channel, and all signals pass through the DCS start circuit. If the DCS module fails, it will cause the oil pump to fail to start. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a steam turbine generator set emergency DC oil pump control system, which solves the problems of existing systems having a single logic circuit, only starting the emergency DC backup oil pump through the DCS control system without other interlocks; long circuit cables that are susceptible to interference; and a lack of priority mechanism, requiring emergency control panel commands to go through multiple levels of transfer, making it impossible to achieve one-button start-up.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a DC oil pump control system for a steam turbine generator set in emergency operation, comprising an operating panel button, a pressure switch, a contactor, an intermediate relay, an air switch, a distributed control system (DCS), an emergency stop button, and a selector button. The contactor includes a main contactor KM1 and an auxiliary contactor KM2; the intermediate relay includes a first intermediate relay KA1 and a second intermediate relay KA2; the input terminal of the pressure switch is connected to a lubricating oil pipeline, and the output terminal includes a first output terminal and a second output terminal. The first output terminal is connected to the coil of the main contactor KM1, and the second output terminal is connected to the coil of the second intermediate relay KA2; the closed contacts A106 and A107 of the operating panel button are connected to the coil of the main contactor KM1; the distributed control system (DCS) receives the contact signal of the second intermediate relay KA2, and its output terminal is connected to the coil of the first intermediate relay KA1; the contacts of the first intermediate relay KA1 are connected to the coil circuit of the main contactor KM1; and the emergency stop button is connected in parallel across the coil of the main contactor KM1.

[0008] Furthermore, the low-voltage signal output from the pressure switch is sent to the local control cabinet and the distributed control system (DCS). After receiving the low-voltage signal, the local control cabinet starts the DC oil pump through a hard interlock. After receiving the low-voltage signal, the DCS starts the DC oil pump through a soft interlock. The output terminal of the control panel button is connected to the coil of the main contactor KM1 to control the start of the DC oil pump.

[0009] Furthermore, the conversion buttons include a first conversion button SA1 and a second conversion button SA2; the DC oil pump control system has four independent start paths: the operator console direct start path, the field and DCS self-start path, the DCS remote start path, and the field control cabinet start path. The four paths are independent of each other and achieve mutual exclusion of states through the conversion buttons SA1 and SA2.

[0010] Furthermore, the direct-start path of the control panel connects all changeover buttons and intermediate relays, and is directly connected to the coil of the main contactor KM1, giving it the highest response priority.

[0011] Furthermore, the on-site and DCS self-starting paths, pressure switches and actions are triggered synchronously, and hard interlocking is initiated on-site; soft interlocking signals are sent to the distributed control system (DCS), achieving dual response protection.

[0012] Furthermore, the DCS remote start path includes a self-locking circuit. The DCS start command triggers the main contactor KM1 to close, and at the same time, the auxiliary normally open contact of the main contactor KM1 closes to form a self-locking circuit.

[0013] Furthermore, the start and stop control of the field control cabinet's start path is directly implemented by emergency buttons SB1 and SB2, independent of the distributed control system DCS and pressure switch logic.

[0014] Furthermore, the DC oil pump control cabinet has a dual power supply protection architecture; the air switch includes a first air switch and a second air switch; the first air switch is connected in series with the power input terminal of the control circuit; the second air switch is connected in series with the main power supply circuit of the DC oil pump.

[0015] This invention also provides a control method for an emergency DC oil pump system of a steam turbine generator set, comprising the following steps:

[0016] 1) Real-time monitoring of the lubricating oil pressure of the steam turbine generator set via a pressure switch;

[0017] 2) When the lubricating oil pressure is lower than the preset threshold, the hard interlock start path is triggered, and the contacts of the pressure switch directly connect the coil circuit of the main contactor KM1 to start the DC oil pump.

[0018] 3) Synchronous trigger soft interlock start path: The contacts of the pressure switch drive the second intermediate relay KA2, which transmits the low pressure signal to the distributed control system DCS system. The distributed control system DCS issues a start command to the coil circuit of the main contactor KM1, starts the DC oil pump, and forms a self-locking circuit to maintain operation.

[0019] 4) Start via field control cabinet: Switch the selector button to local, press the emergency stop button SB1, connect the coil of the main contactor KM1, and start the DC oil pump;

[0020] 5) Provide an emergency start path: The signal lines of the control panel buttons are connected to the coil circuit of the main contactor KM1, bridging all logic control links;

[0021] The technical effects of this invention are as follows:

[0022] (1) The turbine generator set emergency DC oil pump control system of the present invention has four independent start-up paths: hard interlock, soft interlock, emergency start on the control panel, and control on the field control cabinet. All of them operate independently, without dependence on or shielding each other. Even if one path fails due to a fault, the other path can still independently ensure the oil pump starts, realizing multiple redundancy protection and greatly improving the overall fault tolerance and reliability of the control system.

[0023] (2) The emergency start button signal on the control panel is directly connected to the main contactor coil, bridging the changeover switch and the normal start logic. This ensures that in the event of an abnormality in the control circuit, the operator can directly and forcibly start the DC oil pump through the emergency button, providing the highest priority channel for emergency operations.

[0024] (3) The structure is simple, easy to implement and maintain, and the components used are all common and standard electrical components. The control logic is clear and intuitive, and the principle is simple and easy to understand.

[0025] (4) The control cabinet has a compact structure and small size, which reduces manufacturing costs and installation space requirements, and also makes later maintenance and repair more convenient and faster. Attached Figure Description

[0026] Figure 1 This is a circuit diagram of an emergency DC oil pump control system for a steam turbine generator set according to the present invention, wherein KM1 is the main contactor, KM2 is the auxiliary contactor, KA1 and KA2 are intermediate relays, SA1 and SA2 are changeover buttons, and SB1 and SB2 are emergency buttons. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. In the present invention, the term "connection" includes both signal transmission and data interaction achieved through wired connections with actual lines and signal transmission and data interaction achieved through wireless connections via wireless transmission technology.

[0028] like Figure 1 As shown, a DC oil pump control system for a steam turbine generator set includes control panel buttons, pressure switches, contactors, intermediate relays, air switches, a DCS system, emergency stop buttons, and changeover buttons. The contactors include a main contactor KM1 and an auxiliary contactor KM2; the intermediate relays include a first intermediate relay KA1 and a second intermediate relay KA2; the air switches include a first air switch QF1 and a second air switch QF2; the emergency stop buttons include SB1 and SB2; and the changeover buttons include SA1 and SA2.

[0029] This system features a dual-power protection architecture. The first air switch, QF1, is connected in series with the positive input terminal of the DC power supply in the control circuit, serving as the control circuit's opening / closing mechanism and short-circuit protection. The second air switch, QF2, is connected in series with the main power supply circuit of the DC oil pump motor, serving as the main circuit's opening / closing mechanism and short-circuit protection. The system uses the main contactor KM1 as the core actuator for starting the DC oil pump motor. The coil operating voltage of the main contactor KM1 matches the DC voltage of the control circuit. When the coil of the main contactor KM1 is energized, its three-phase main contacts close, connecting the DC oil pump motor power supply; simultaneously, its auxiliary normally open contacts close, forming a self-locking mechanism in a specific path. The auxiliary contactor KM2 provides redundant backup for the main circuit control; its coil and control logic can be configured according to actual needs, such as parallel control with KM1 or for segmented starting.

[0030] The pressure switch is used to monitor lubricating oil pressure in real time. Its input terminal is connected to the lubricating oil header of the turbine generator set via a pipeline. When the oil pressure is lower than the preset trip threshold, its internal mechanism activates, causing the normally open contacts A104-A105 to close. The pressure switch output terminal is divided into two paths: the first hard interlock path is directly led out with a wire connected to one end of the coil of the main contactor KM1; the second soft interlock signal path is connected to the coil of the second intermediate relay KA2.

[0031] The coil of the first intermediate relay KA1 is controlled by the digital output module of the DCS system. When the DCS issues a start command, it outputs a matching voltage signal to the coil of the first intermediate relay KA1, energizing it. The normally open contact of the first intermediate relay KA1 then closes; this contact is connected in series in the coil circuit of the main contactor KM1, serving as the actuator for DCS remote start and soft interlock start. The coil of the second intermediate relay KA2 is driven by the second output of the pressure switch. When the pressure switch is closed, the coil of the second intermediate relay KA2 is energized, its normally open contact closes, and a "low lubricating oil pressure" digital signal is sent to the digital input module of the DCS system.

[0032] The control panel buttons have a pair of normally open contacts that are directly and hardwired to the coil circuit of the main contactor KM1 via a control cable, a path independent of all other control logic. The field control cabinet buttons include changeover buttons SB1 and SB2, where SB1 is the start button and SB2 is the stop button, mounted on the local control panel of the DC oil pump.

[0033] The selector button SA1 is used to switch between "local" and "remote" modes. When turned to the "local" position, it connects the control circuits of selector buttons SB1 and SB2; when turned to the "remote" position, it disconnects the selector button circuits, enabling the DCS-side logic in the DCS remote control and pressure auto-start functions. The selector button SA2 is used to enable or disable the "pressure auto-start" function. When turned to the "enabled" position, it connects the circuit from the pressure switch PS to the second intermediate relay KA2 coil and the circuit from the PS hard-interlock output to the main contactor KM1 coil; when turned to the "disabled" position, it disconnects these circuits, disabling the automatic pressure start function and retaining only the manual start mode.

[0034] The DCS system is the logic processing and remote operation center of the system. Its hardware includes a DI module for receiving the low pressure signal from the second intermediate relay KA2, and a DO module for outputting start commands to the coil of the first intermediate relay KA1. The DCS has pre-installed corresponding control logic programs to judge the input signals and issue output commands.

[0035] Starting resistors R1 and R2 are connected in series in the coil circuits of the main contactor KM1 and the auxiliary contactor KM2, respectively, to limit the inrush current when the coil is energized, protect the coil and contacts, and improve the life of the components.

[0036] The specific connection relationships of each component are as follows: Figure 1 As shown: After passing through QF1, the control power supply forms multiple parallel branches that ultimately converge at one end of the main contactor KM1 coil. The other end of the main contactor KM1 coil is connected to the negative terminal of the power supply. These branches consist of the operating panel button contacts A106-A107, pressure switch contacts A104-A105, the first intermediate relay KA1 contact KA1-1, and a series circuit consisting of emergency buttons SB1 and SB2 and a changeover button SA1. Emergency buttons SB1 and SB2 are connected in parallel across the main contactor KM1 coil, providing direct start / stop control. The circuit from the pressure switch to the second intermediate relay KA2 coil and the circuit from the DCS output to the first intermediate relay KA1 coil are both controlled by the corresponding contacts of the changeover button SA2.

[0037] This system has four independent start paths: a direct start path from the control panel, a field and DCS automatic start path, a DCS remote start path, and a field control cabinet start path. These paths encompass both automatic monitoring and manual intervention, ensuring reliable start of the DC oil pump even in the event of a plant-wide power outage, DCS failure, or localized circuit anomalies. Furthermore, the four paths are independent of each other, with mutual exclusion achieved via switch buttons SA1 and SA2.

[0038] The four startup paths provided by this invention will be described in detail below with reference to the accompanying drawings.

[0039] 1. Control panel start path

[0040] The direct start path from the control panel is the highest priority control method in the system, used for operators to directly intervene and start the DC oil pump in emergency situations. The specific implementation steps are as follows:

[0041] 1) When operators observe an abnormal drop in oil pressure, system alarm, or other emergency situation on the control panel in the central control room, they determine that the DC oil pump needs to be started immediately.

[0042] 2) Press the control panel button. The button's mechanical structure causes the normally open contacts A106 and A107 to close momentarily.

[0043] 3) The output cable of the control panel is directly connected to the coil terminal of the main contactor KM1, and the current flows through the KM1 coil through the closed A106-A107 contacts.

[0044] 4) When the KM1 coil is energized, the main contactor is attracted, its three-phase main contacts are closed, the DC oil pump motor is connected to the power supply, and it starts at full voltage.

[0045] This path bypasses any transfer switches, intermediate relays, or DCS systems, achieving millisecond-level response and representing the highest priority control method in the system. Releasing the button opens the contacts, stopping the oil pump. To maintain operation, a self-locking mechanism must be implemented via another path.

[0046] 2. On-site and DCS auto-start paths

[0047] This path monitors the lubricating oil pressure in real time via a pressure switch. When the oil pressure falls below a set threshold, it simultaneously triggers both a hard interlock local start and a soft interlock DCS start, achieving dual redundancy protection in both electrical and logical aspects. The specific steps are as follows:

[0048] 1) The pressure switch is installed in the lubrication oil pipeline of the steam turbine unit to monitor the oil pressure in real time. When the pressure is lower than the set value, its internal mechanism is activated, and the normally open contacts A104-A105 close.

[0049] 2) The first output of the pressure switch is directly connected to the KM1 coil; after A104-A105 is closed, the current flows directly through this path to energize KM1, close the main contacts, and start the oil pump.

[0050] 3) Soft interlock start: The second output of the pressure switch is connected to the coil of the second intermediate relay KA2; when A104-A105 close, KA2 is energized, its normally open contact closes, and a "low lubricating oil pressure" digital signal is sent to the DI module of the DCS system; after receiving the signal, the system judges it through its internal logic program and outputs a 24V DC start command through the DO module; the start command is transmitted to the coil of the first intermediate relay KA1, KA1 is energized, and its normally open contact closes; the KA1 contact is connected to the KM1 coil circuit, and the current through this path energizes KM1, and the oil pump starts.

[0051] This path achieves a dual response to the pressure signal, ensuring high reliability. The changeover switch SA2 must be set to the "on" position beforehand to put the KA2 coil circuit in standby mode.

[0052] 3. DCS remote boot path

[0053] This path allows for remote manual start and stop operations. Operators issue commands through the DCS interface, the system responds and forms a self-locking mechanism. The specific steps are as follows:

[0054] 1) Turn the selector button SA2 to the "remote control" position. The relevant contacts of SA2 will close, and the coil circuit of the intermediate relay KA1 will be connected. A set of normally open contacts of KA1 will close, sending a "ready" signal to the DCS system. The DCS screen will display the "remote controllable" status.

[0055] 2) The operator clicks the "DC oil pump start" button on the DCS operation interface, and the DCS outputs a start signal through the DO module.

[0056] 3) The DCS output signal is transmitted to the KA1 coil, and KA1 is energized; another set of normally open contacts of KA1 closes, connecting the KM1 coil circuit; KM1 is energized and attracted, the main contacts close, and the oil pump starts.

[0057] 4) The auxiliary normally open contact of KM1 is connected in parallel with the KA1 contact. When KM1 is energized, the auxiliary contact closes to form a self-locking circuit. At this time, even if the DCS output signal is withdrawn or the KA1 contact is opened, the KM1 coil will still be energized through the self-locking circuit, and the oil pump will continue to run.

[0058] 5) When the operator clicks the "Stop" button on the DCS interface, the DCS output signal is canceled, KA1 is de-energized, its contacts are opened, the self-locking circuit is released, the KM1 coil is de-energized, and the oil pump stops.

[0059] 4. Startup path of the field control cabinet

[0060] This approach provides local operation capability completely independent of the DCS and pressure monitoring system for on-site commissioning or system maintenance. The specific steps are as follows:

[0061] 1) Turn the switch button SA1 to the "local" position. The SA1 contact will switch, putting the control loops of the field buttons SB1 and SB2 into standby mode.

[0062] 2) Press the “Start” button SB1 on the field control cabinet. Its normally open contact will close, and the current will flow directly through the KM1 coil.

[0063] 3) When KM1 is energized and engaged, the main contacts close, and the DC oil pump starts. Since this path does not have a self-locking circuit, SB1 must be continuously pressed to keep the oil pump running.

[0064] 4) Release SB1 or press the "Stop" button SB2, the KM1 coil circuit is de-energized, the main contacts open, and the oil pump stops.

[0065] This approach does not rely on a DCS system or pressure switch, offers a direct response, and is easy to operate.

[0066] This system uses switch buttons SA1 and SA2 to achieve mechanical and electrical mutual exclusion between the paths: SA1 is used to switch between "local" and "remote" modes, determining which is effective—the local button or the remote control; SA2 is used to enable or disable the "pressure self-start" function, controlling the hard interlock and KA2 signal path. The direct-start path on the control panel is connected across all selector switches and relays and is effective in any mode. Although the four paths are mutually exclusive through SA1 and SA2, they are electrically configured in parallel and independently, so a failure in one path does not affect the normal operation of the other paths.

[0067] The role and effect of the embodiments

[0068] This invention provides an emergency DC oil pump control system for steam turbine generator sets. Through the design of four independent control paths, the DC oil pump can still be reliably started when the entire plant loses power or when there is a partial system failure, effectively avoiding damage to the bearings due to lack of oil.

[0069] This system implements multiple redundant control mechanisms. The four paths—operator console start-up, field and DCS automatic start-up, DCS remote start-up, and field manual start-up—are independent of each other. If one path fails, the other paths can still start the oil pump normally, greatly improving the system's reliability and fault tolerance.

[0070] The emergency start button signal on the control panel is directly connected to the main contactor coil, bridging the changeover switch and the conventional start logic to achieve millisecond-level emergency start. This ensures that in the event of a control circuit malfunction, operators can directly and forcibly start the DC oil pump via the emergency button, providing the highest priority channel for emergency operations.

[0071] The combination of soft and hard interlocks in the field and DCS self-starting path ensures instantaneous response when the oil pressure is low through hard wiring, while the DCS performs status verification and system recording to avoid malfunctions and improve the accuracy of actions.

[0072] This system has a simple structure and mainly uses conventional electrical components such as contactors, relays, and changeover buttons. It does not require complex control modules, which facilitates maintenance, troubleshooting, and spare parts management, and reduces implementation and operation costs.

[0073] In addition, the system has a dual power supply protection architecture, with separate air switches for the control circuit and the main circuit, to prevent system failure caused by a single power supply failure, thus further enhancing overall safety.

[0074] In summary, the embodiments of the present invention significantly improve the reliability, response speed and system safety of emergency DC oil pump control, and are especially suitable for high-risk conditions such as plant-wide power outages, and have high engineering application value.

[0075] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A turbine generator set emergency DC oil pump control system comprising an operator panel button, a pressure switch, a contactor, an intermediate relay, an air switch, a distributed control system (DCS), an emergency button, a transfer button, wherein: The contactor comprises a main contactor KM1 and a sub contactor KM2; the intermediate relay comprises a first intermediate relay KA1 and a second intermediate relay KA2; the input end of the pressure switch is connected to a lubricating oil pipeline, the output end comprises a first output end and a second output end, the first output end is connected to the coil of the main contactor KM1, and the second output end is connected to the coil of the second intermediate relay KA2; the closed contacts A106 and A107 of the operation platform button are connected to the coil of the main contactor KM1; the distributed control system (DCS) receives the contact signal of the second intermediate relay KA2, and the output end is connected to the coil of the first intermediate relay KA1; the contacts of the first intermediate relay KA1 are connected to the coil loop of the main contactor KM1; and the emergency button is connected in parallel to the two ends of the coil of the main contactor KM1.

2. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 1, characterized in that: The low-pressure signal of the pressure switch is output to the local control cabinet and the distributed control system (DCS); after receiving the low-pressure signal, the local control cabinet starts the direct-current oil pump through hard interlocking; after receiving the low-pressure signal, the distributed control system (DCS) starts the direct-current oil pump through soft interlocking; the output end of the operation platform button is connected to the coil of the main contactor KM1 to control the start of the direct-current oil pump.

3. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 1, characterized in that: The conversion button comprises a first conversion button SA1 and a second conversion button SA2; the direct-current oil pump control system has four independent start paths, namely an operation platform direct start path, a local and DCS self-start path, a DCS remote start path and a local control cabinet start path, and the four paths are independent of each other, and state mutual exclusion is realized through the conversion buttons SA1 and SA2.

4. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 3, characterized in that: The operation platform direct start path is connected to the coil of the main contactor KM1 directly and has the highest response priority.

5. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 3, characterized in that: The local and DCS self-start path is triggered synchronously with the pressure switch, and the hard interlocking field start is realized; the soft interlocking signal is sent to the distributed control system (DCS) to realize double-response guarantee.

6. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 3, characterized in that: The DCS remote start path comprises a self-locking loop, and the start instruction of the distributed control system (DCS) triggers the closure of the main contactor KM1, and the auxiliary normally open contact of the main contactor KM1 is closed to form self-locking.

7. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 3, characterized in that: The start-stop control of the local control cabinet start path is directly realized by the emergency buttons SB1 and SB2, and is independent of the distributed control system (DCS) and the pressure switch logic.

8. A control system for an emergency DC oil pump of a turbogenerator unit according to claim 1, characterized in that: The direct-current oil pump control cabinet has a dual-power protection architecture; the air switch comprises a first air switch and a second air switch; the first air switch is connected in series to the power input end of the control loop; and the second air switch is connected in series to the main power loop of the direct-current oil pump.

9. A control method for a turbogenerator set emergency DC oil pump system according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: 1) The pressure of the lubricating oil of the steam turbine generator set is monitored in real time through the pressure switch; 2) When the pressure of the lubricating oil is lower than a preset threshold, a hard interlocking start path is triggered, the contacts of the pressure switch directly connect the coil loop of the main contactor KM1, and the direct-current oil pump is started; 3) Synchronous trigger soft interlocking start path: the contact of pressure switch drives the second intermediate relay KA2, transmits the low pressure signal to the distributed control system (DCS) system, and issues the start instruction to the coil loop of the main contactor KM1 by the distributed control system (DCS), starts the DC oil pump, and forms a self-locking loop to maintain operation; 4) Start through the field control cabinet: switch the button to on-site, press the emergency button SB1, connect the coil of the main contactor KM1, and start the DC oil pump; 5) Provide an emergency start path: the signal line of the operation table button is connected to the coil loop of the main contactor KM1, and all logic control links are bridged.

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