Fixed-point meshing control method and device for SSS clutch of NCB steam turbine

Abstract

The invention discloses a fixed-point meshing control method and device for an SSS clutch of an NCB steam turbine, and relates to the technical field of power station steam turbine control. According to the main technical scheme, when the load of a heat supply network is reduced and a heat supply unit needs to be switched from a backpressure heat supply mode to an extraction condensing heat supply mode, a variable frequency motor connected to the free end of a low-pressure rotor is started, the variable frequency motor is introduced to provide a power source, and especially under the working conditions that little steam enters a low-pressure air cylinder and steam does not form effective driving force, the variable frequency motor is started; controllable mechanical power provided by the variable frequency motor is utilized, the accuracy of the speed raising process of the low-pressure rotor can be improved and controlled, and meshing of the two rotors within a preset target phase interval at the synchronization moment is achieved by tracking a preset speed raising curve at high precision, so that a meshing deterioration area in the circumferential direction of the SSS clutch is effectively avoided, and the stability of the clutch is improved. According to the method, the rotating speed control precision and the repeatability of the meshing phase are remarkably improved, and a feasible solution is provided for fixed-point meshing control of the SSS clutch.

Description

Technical Field

[0001] This application relates to the field of power plant turbine control technology, and in particular to a method and device for fixed-point engagement control of the SSS clutch of an NCB turbine. Background Technology

[0002] In northern my country, combined cycle heating units generally adopt "pure condensing-extraction condensing-back pressure" three-condition steam turbines (NCB steam turbines). The low-pressure cylinder and the intermediate-high pressure cylinder are equipped with an automatic synchronizing self-shifting clutch (SSS clutch) to realize online engagement and disengagement of the shaft system and improve the flexibility of electrothermal regulation.

[0003] During the switching between back pressure and extraction / condensation modes, the low-pressure rotor needs to be restarted and synchronized with the intermediate and high-pressure rotors before being automatically engaged by the SSS clutch. However, this clutch is a purely mechanical structure, and the engagement phase is random, resulting in inconsistent radial relative positions of the shaft system after each connection, causing vibration fluctuations. Field monitoring shows that there are "good" and "bad" engagement phases; a phase falling into the bad phase will significantly aggravate bearing vibration, affecting the safe and stable operation of the unit.

[0004] Currently, theoretically, fixed-point engagement can be achieved by controlling the acceleration curve of the low-pressure rotor to avoid the deterioration zone. However, in practical applications, the nonlinear flow characteristics of the low-pressure cylinder inlet butterfly valve and its tendency to overshoot at small openings, coupled with fluctuations in inlet parameters due to operating conditions, result in insufficient speed control accuracy and difficulty in precisely controlling the engagement phase. Therefore, it is difficult to effectively implement fixed-point engagement control of the SSS clutch in practical applications, which restricts the engineering application of vibration optimization measures and is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a method and apparatus for controlling the fixed-point engagement of an SSS clutch in an NCB steam turbine. The main purpose is to introduce a controllable power source as the primary power source when the heating network load decreases and the heating unit needs to switch from back-pressure heating mode to extraction-condensing heating mode, or to completely replace its power function when the steam inlet of the low-pressure cylinder is insufficient to provide effective driving force. This can significantly improve the control accuracy of the low-pressure rotor speed-up curve, thereby providing effective technical support for achieving the fixed-point engagement of the SSS clutch, and thus providing a practical solution for the fixed-point engagement control of the SSS clutch.

[0006] To achieve the above objectives, this application mainly provides the following technical solutions: The first aspect of this application provides a method for fixed-point engagement control of the SSS clutch in an NCB steam turbine, applied to a distributed control system for NCB steam turbine operating condition switching control, the method comprising: When the heating network load decreases and the heating unit needs to switch from back pressure heating mode back to extraction condensing heating mode, the variable frequency motor connected to the free end of the low-pressure rotor is started. The variable frequency motor is used to directly drive the low-pressure rotor to speed up and rotate through mechanical connection. During the process of using the power source provided by the variable frequency motor to drive the low-pressure rotor to accelerate according to the preset speed-up curve, if the speed of the low-pressure rotor is detected to reach the first preset threshold, a composite control strategy combining preset feedforward and feedback is activated for processing, so that the real-time relative meshing angle between the low-pressure rotor and the intermediate-high pressure rotor gradually approaches the preset target meshing angle; wherein, the intermediate-high pressure rotor and the low-pressure rotor are arranged on separate shafts, and after the heating unit completes the switch from the back pressure heating mode to the extraction condensation heating mode, the intermediate-high pressure rotor transmits power to the low-pressure rotor through the SSS clutch to drive the low-pressure cylinder to operate under load; If the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within the second preset threshold, it is determined that the SSS clutch tooth groove has completed fixed-point meshing. After confirming that the SSS clutch has completed the fixed-point engagement, the locking mechanism is triggered to fix the SSS clutch and stop the variable frequency motor; By gradually controlling the opening of the low-pressure cylinder intake valve to full opening, the steam entering the low-pressure cylinder is used to drive the low-pressure cylinder to operate under load, thereby completing the switching of the heating mode of the heating unit.

[0007] A second aspect of this application provides a fixed-point engagement control device for an NCB turbine SSS clutch, the device comprising: The starting unit is used to start the variable frequency motor connected to the free end of the low-pressure rotor when the heating network load decreases and the heating unit needs to switch from back pressure heating mode to extraction condensing heating mode. The variable frequency motor is used to directly drive the low-pressure rotor to accelerate and rotate through mechanical connection. The first monitoring unit is used to monitor whether the rotational speed of the low-voltage rotor reaches a first preset threshold during the process of driving the low-voltage rotor to accelerate according to a preset speed-up curve using the power source provided by the variable frequency motor. The processing unit is used to activate a composite control strategy combining preset feedforward and feedback if the speed of the low-pressure rotor is detected to reach a first preset threshold, so that the real-time relative meshing angle between the low-pressure rotor and the intermediate-pressure rotor gradually approaches the preset target meshing angle; wherein the intermediate-pressure rotor and the low-pressure rotor are arranged on separate shafts, and after the heating unit completes the switch from the back pressure heating mode to the extraction condensation heating mode, the intermediate-pressure rotor transmits power to the low-pressure rotor through the SSS clutch to drive the low-pressure cylinder to operate under load; The second monitoring unit is used to monitor whether the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within a second preset threshold. The determining unit is used to determine that the SSS clutch tooth groove has completed fixed-point engagement if the detected deviation converges to within the second preset threshold. The first execution unit is used to trigger the locking mechanism to fix the SSS clutch and stop the variable frequency motor after determining that the SSS clutch has completed the fixed-point engagement; The second execution unit is used to gradually control the opening of the low-pressure cylinder intake valve to fully open, and use the steam entering the low-pressure cylinder to drive the low-pressure cylinder to operate under load, thereby completing the switching of the heating mode of the heating unit.

[0008] A third aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the NCB turbine SSS clutch fixed-point engagement control method as described above.

[0009] A fourth aspect of this application provides an electronic device, the device including at least one processor, and at least one memory and bus connected to the processor; The processor and the memory communicate with each other via the bus. The processor is used to call program instructions in the memory to execute the NCB turbine SSS clutch fixed-point engagement control method as described above.

[0010] By employing the above-described technical solution, the technical solution provided in this application has at least the following advantages: This application provides a method and device for fixed-point engagement control of the SSS clutch in an NCB steam turbine, applied to a distributed control system for NCB steam turbine operating condition switching control. When the heating network load decreases and the heating unit needs to switch from back-pressure heating mode back to extraction-condensing heating mode, a variable frequency motor connected to the free end of the low-pressure rotor is started. The power source provided by the variable frequency motor drives the low-pressure rotor to accelerate according to a preset acceleration curve. During the acceleration and rotation of the low-pressure rotor, when the low-pressure rotor speed is detected to reach a certain threshold, a composite control strategy combining preset feedforward and feedback is activated to process the rotor, so that the real-time relative engagement angle between the low-pressure rotor and the intermediate and high-pressure rotors gradually approaches the preset target engagement angle. When the deviation between the real-time relative engagement angle of the two rotors and the target engagement angle converges to within a certain threshold, the SSS clutch is determined. The clutch teeth complete the fixed-point engagement, and then the locking mechanism is triggered to fix the SSS clutch and stop the variable frequency motor. Subsequently, by gradually controlling the opening of the low-pressure cylinder intake valve to fully open, the steam entering the low-pressure cylinder drives the low-pressure cylinder to run under load, thus completing the switching of the heating mode of the heating unit.

[0011] Compared to existing technologies that suffer from insufficient speed control accuracy due to factors such as the nonlinear flow characteristics of the low-pressure cylinder inlet butterfly valve, making it difficult to effectively implement fixed-point engagement control of the SSS clutch, this application introduces a variable frequency motor as the power source. Especially under conditions where there is very little steam entering the low-pressure cylinder and the steam does not form an effective driving force, the controllable mechanical power provided by the variable frequency motor can improve the accuracy of regulating the acceleration process of the low-pressure rotor. By tracking the preset acceleration curve with high precision, the two rotors can complete engagement within the preset target phase range at the synchronous moment, thereby effectively avoiding the engagement deterioration zone in the circumferential direction of the SSS clutch. This application significantly improves the speed control accuracy and the repeatability of the engagement phase, providing a practical solution for fixed-point engagement control of the SSS clutch.

[0012] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0013] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a fixed-point engagement control method for an NCB turbine SSS clutch is provided in an embodiment of this application; Figure 2 This is a schematic diagram of the original arrangement of the NCB turbine shaft system provided in an embodiment of this application; Figure 3 This is a schematic diagram of the shaft system arrangement after adding a variable frequency drive motor, provided in an embodiment of this application. Figure 4 This is a schematic diagram of key phase synchronization sampling provided in an embodiment of this application; Figure 5 A block diagram of a fixed-point engagement control device for an NCB turbine SSS clutch provided in this application embodiment; Figure 6 A block diagram of another NCB turbine SSS clutch fixed-point engagement control device provided in this application embodiment. Detailed Implementation

[0014] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0015] In northern my country, combined cycle units are mostly configured as cogeneration units, and commonly use "pure condensing-extraction condensing-back pressure" three-condition steam turbines (hereinafter referred to as NCB turbines). This type of turbine is equipped with an automatic synchronizing self-shifting clutch (SSS clutch) in the shaft system between the low-pressure cylinder and the intermediate-high-pressure cylinder.

[0016] When the heating network has no heat load or the heat load demand is low, the low-pressure rotor and the intermediate-pressure rotor are engaged by the SSS clutch to form an integral shaft system, and the turbine operates in pure condensing power generation or extraction-condensing heating mode. As the heat load increases, when the extraction-condensing heating capacity cannot meet the heating network demand, the low-pressure cylinder inlet butterfly valve is closed, cutting off the steam supply to the low-pressure cylinder. The low-pressure rotor loses its driving force and its speed decreases. When its speed is lower than that of the intermediate-pressure rotor, the SSS clutch automatically disengages, and all the exhaust steam from the intermediate-pressure cylinder is introduced into the heating network, and the unit switches to back-pressure heating mode. After the heat load decreases, the low-pressure cylinder inlet valve is reopened, and the low-pressure rotor starts rotating again. Once its speed is synchronized with that of the intermediate-pressure rotor, the SSS clutch re-engages, and the unit returns to extraction-condensing heating mode.

[0017] The SSS clutch is a purely mechanical self-synchronizing clutch device. Its working principle is based on the relative speed relationship between the input and output sides: when the input side speed is greater than or equal to the output side speed, the internal ratchet-pawl mechanism is triggered to achieve automatic engagement; otherwise, it automatically disengages. NCB turbines utilize the SSS clutch to achieve online disconnection and reconnection of low-pressure cylinders, significantly improving the flexibility of electrical and thermal load regulation.

[0018] However, this type of variable shaft system structure also causes a series of unique vibration problems during the switching of operating conditions. Long-term vibration monitoring of multiple NCB steam turbines shows that during the alternation of extraction and condensation heating modes, some bearings exhibit significant vibration fluctuations, making it difficult to stably control the shaft system vibration state throughout the heating season and seriously threatening the safe and reliable operation of the unit.

[0019] In-depth analysis reveals that the vibration fluctuations primarily originate from the mechanical characteristics of the SSS clutch itself, particularly the uncertainty of its engagement phase. Specifically, during the switch from back-pressure heating mode to extraction-condensing heating mode, the SSS clutch engages after the low-pressure rotor reaches synchronous speed with the intermediate and high-pressure rotors. However, due to the lack of phase control, the relative positions of the two rotors in the circumferential direction are random during each engagement. Compared to traditional fixed shaft systems, the intermediate and high-pressure rotors in an NCB turbine maintain their positions, while the low-pressure rotor undergoes a random radial phase shift before connecting with the intermediate and high-pressure rotors during each operating condition switch. This leads to uncontrollable changes in the dynamic characteristics of the entire shaft system, thereby inducing vibration fluctuations. Field tests further verify that the SSS clutch exhibits a "good engagement zone" and a "bad engagement zone" in the circumferential direction, and the engagement phase falling into different zones has a significant impact on the shaft system's vibration response.

[0020] To address the randomness of the SSS clutch engagement phase, theoretically, the engagement phase can be predicted in real time during the low-pressure rotor's initial acceleration by optimizing the engagement control strategy, and the speed can be fine-tuned near synchronous speed to guide the two rotors to engage within a preset optimal phase range. However, in practical engineering applications, it has been found that butterfly valves are typically used for the low-pressure cylinder inlet valves of NCB turbines. Their flow-opening characteristics exhibit strong nonlinearity, especially with significant abrupt changes in flow gain in the small opening range, which easily leads to control overshoot or oscillation. This makes it difficult to accurately adjust the low-pressure cylinder inlet steam flow, resulting in a significant deviation between the actual low-pressure rotor acceleration curve and the set command. Furthermore, the low-pressure cylinder inlet steam parameters (such as pressure and temperature) also dynamically change with heating conditions, further weakening the stability of speed control.

[0021] Since the SSS clutch fixed-point engagement control strategy is highly dependent on the precise control of the low-pressure rotor speed-up process, the aforementioned control challenges make it difficult for NCB turbines to achieve high-precision phase-controllable engagement, which severely restricts the effective implementation of vibration suppression measures based on engagement phase optimization.

[0022] To this end, the inventors discovered through research that if a controllable power source is introduced as the dominant power source during the low-pressure rotor speed-up process, or if the low-pressure cylinder's steam intake is insufficient to provide effective driving force, its power function can be completely replaced, which can significantly improve the control accuracy of the low-pressure rotor speed-up curve, thereby providing effective technical support for achieving the fixed-point engagement of the SSS clutch.

[0023] Based on the above considerations, this application provides a method for controlling the fixed-point engagement of the SSS clutch in an NCB turbine. The main implementer of this method is a device on a Distributed Control System (DCS) applied to the NCB turbine's operating condition switching control. The DCS system is the core automated carrier for this method to achieve "automatic operating condition switching and fixed-point engagement of the SSS clutch," ensuring the reliability, accuracy, and safety of the control process. Figure 1 As shown, this method provides the following specific implementation steps: 101-105; Step 101: When the heating network load decreases and the heating unit needs to switch from back pressure heating mode back to extraction condensing heating mode, start the variable frequency motor connected to the free end of the low-pressure rotor. The variable frequency motor is used to directly drive the low-pressure rotor to speed up and rotate through mechanical connection.

[0024] like Figure 2 This application provides a schematic diagram of the original layout of the NCB turbine shaft system. The shaft system is a series single-shaft structure. The core components on the shaft system are mechanically connected sequentially along the same axis. The specific connection sequence is as follows: starting from the power output end, the exciter, generator, intermediate-pressure cylinder, high-pressure cylinder, SSS clutch, and low-pressure cylinder are connected in sequence. At the same time, these components are mechanically connected by couplings. The entire shaft system is also equipped with bearings numbered 1 to 9. These bearings provide radial and axial support to the corresponding shaft segments to ensure the stability of the shaft system during high-speed rotation.

[0025] Reference Figure 2 As shown, the working principle of the heating unit switching from back-pressure heating mode to extraction-condensing heating mode is as follows: In back-pressure heating mode, steam enters the high-pressure cylinder and the intermediate-pressure cylinder in sequence to complete the work process. All the steam after the work is done is used for heating. At this time, there is no steam input to the low-pressure cylinder, and it is in a stopped state. The SSS clutch also remains disengaged. Only the high-pressure and intermediate-pressure rotors drive the generator in the entire shaft system.

[0026] When the load on the heating network decreases, it is necessary to switch the operating mode to the extraction condensing heating mode (which can simultaneously meet the needs of heating and power generation). To switch to this mode, the low-pressure cylinder must first be started and put into operation.

[0027] In the original shaft system, the method for switching modes is to directly introduce driving steam into the low-pressure cylinder, using the power of the steam to drive the low-pressure rotor to increase its speed; after the speed of the low-pressure rotor is synchronized with the speed of the intermediate and high-pressure rotors, the SSS clutch is controlled to complete the engagement action, thereby realizing the linkage operation of the intermediate and high-pressure rotors and the low-pressure rotor.

[0028] However, the above working principle has certain limitations: the steam-driven method cannot precisely control the acceleration process, which can easily lead to problems such as speed fluctuations and large deviations in the meshing angle.

[0029] Therefore, in this embodiment of the application, a variable frequency motor is added to the end of the low-pressure cylinder (outside bearing 1) on the basis of the original shaft system, and a mechanical connection is achieved with the shaft segment of the low-pressure cylinder through a coupling, resulting in the following... Figure 3 The diagram shown illustrates the shaft arrangement after the addition of a variable frequency drive motor. The variable frequency motor is used to directly drive the low-voltage rotor to accelerate and rotate through a mechanical connection, thereby providing a controllable power source for the low-voltage rotor.

[0030] Step 102: During the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to the preset speed-up curve, if the speed of the low-voltage rotor is detected to reach the first preset threshold, a composite control strategy combining preset feedforward and feedback is activated to process it, so that the real-time relative meshing angle between the low-voltage rotor and the high- and medium-voltage rotors gradually approaches the preset target meshing angle.

[0031] In the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, the embodiments of this application can provide two operating modes: One approach is to completely replace steam power with the controllable mechanical power output by the variable frequency motor, serving as the independent active power source for the low-pressure rotor to rotate; another approach is to provide the active power by the variable frequency motor when a small amount of driving steam is introduced, while the driving steam serves as an auxiliary power source, with the two working together to drive the low-pressure rotor to speed up.

[0032] Regardless of the mode used, the core objective of this application's embodiments is to achieve fixed-point engagement of the SSS clutch within a specified phase range by precisely controlling the acceleration process of the low-pressure rotor, so that the real-time relative meshing angle between it and the high- and medium-pressure rotors quickly and stably approaches the preset target meshing angle.

[0033] Specifically, in actual control operations, the following two implementation methods can be adopted, but are not limited to: Method 1: Adjust the opening of the low-pressure cylinder inlet butterfly valve to the first preset opening, so that the low-pressure cylinder is supplied with the first preset flow of cooling steam to suppress the blade blow-off effect; at the same time, use the controllable mechanical power provided by the variable frequency motor as the only power source to drive the low-pressure rotor to rotate according to the preset speed-up curve.

[0034] Method 2: Further, after adjusting the opening of the low-pressure cylinder inlet butterfly valve to the first preset opening, the opening of the low-pressure cylinder inlet butterfly valve is gradually adjusted from the first preset opening to the second preset opening, so that the low-pressure cylinder is supplied with driving steam at the second preset flow rate; at this time, the controllable mechanical power output by the variable frequency motor is used as the main power source, and the thermal drive generated by the steam is used as the auxiliary power source, and the two work together to drive the low-pressure rotor to speed up and rotate.

[0035] It should be noted that in the embodiments of this application, the terms "first" and "second" are used to distinguish the opening degree of the steam inlet butterfly valve under the conditions of having / not having driven steam in the low-pressure cylinder.

[0036] For example, in the case of no driving steam in the low-pressure cylinder, only a small amount of cooling steam (non-power steam) is introduced, that is, "the opening of the low-pressure cylinder inlet butterfly valve is adjusted to the first preset opening, so that the low-pressure cylinder is supplied with cooling steam at the first preset flow rate". The purpose is to suppress the blower effect caused by the friction between the blades and the air during rotor rotation, and to avoid excessive blade temperature rise and potential thermal damage risks. Moreover, regardless of whether it is method one or method two, the embodiments of this application use "introducing a small amount of cooling steam (non-power steam)" to achieve this purpose.

[0037] In Method 2, based on the "first preset opening degree", the opening degree of the steam inlet butterfly valve is increased to the "second preset opening degree", so that a certain amount of driving steam is introduced into the low-pressure cylinder to provide a cooperative auxiliary power source.

[0038] Regardless of whether it is method one or method two, the existence of a controllable power source as an independent power source or an active power source improves the accuracy of controlling the power input to the low-pressure cylinder, realizes high-precision management of the low-pressure rotor speed-up process, and creates conditions for the subsequent fixed-point engagement of the SSS clutch within the target phase range.

[0039] Furthermore, during the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to the preset speed-up curve, if the speed of the low-voltage rotor is detected to reach the first preset threshold, a composite control strategy combining preset feedforward and feedback is activated for processing. The purpose of providing the "first preset threshold" in this application embodiment is to make the speed of the low-voltage rotor close to that of the high-voltage rotor (i.e., the speeds of the two rotors are close to the synchronous value), for example, but not limited to "the speed is close to 3000 r / min".

[0040] In the initial stage of low-pressure rotor speed-up (speed far below 3000 r / min), the control objective prioritizes shortening the operating condition switching time, with lower requirements for speed accuracy. At this stage, an open-loop coarse-adjustment strategy can be used, relying solely on the power source (such as a variable frequency motor or steam) for rapid speed-up, which can meet efficiency requirements. If a complex feedforward-feedback composite control strategy is activated too early in this stage, it will not only fail to significantly improve control performance but will also increase the computational burden on the control system, reduce dynamic response speed, and consequently affect overall speed-up efficiency.

[0041] When the low-pressure rotor speed approaches the synchronous speed (about 3000 r / min), the speed difference between it and the high-pressure rotor becomes extremely small. The engagement phase (i.e. the relative angle between the two rotors) becomes the key factor affecting whether the SSS clutch can engage successfully. If the phase deviation exceeds the allowable range, it will lead to engagement failure or cause shaft impact vibration.

[0042] Therefore, a combined feedforward and feedback control strategy (feedforward-feedback) needs to be activated at this stage. Specifically, feedforward control predicts the future meshing phase in advance based on the current acceleration rate and rotor dynamic model, suppressing the accumulation of deviations; feedback control dynamically corrects the variable frequency motor output based on the real-time speed difference and phase error between the high-pressure and low-pressure rotors, achieving closed-loop regulation. The two work together to achieve high-precision phase tracking within a narrow phase window, controlling the meshing angle deviation within a preset threshold, thereby ensuring that the SSS clutch smoothly and reliably completes fixed-point engagement.

[0043] Furthermore, in some specific instances, if the speed of the low-pressure rotor is detected to reach a first preset threshold, a composite control strategy combining preset feedforward and feedback is activated to process the rotor, so that the real-time relative meshing angle between the two rotors gradually approaches the preset target meshing angle. The following specific implementation steps can be provided: A1. Based on the synchronously acquired key phase signals of the high-pressure and medium-pressure rotors and the low-pressure rotor, the current speed of the high-pressure and medium-pressure rotors, the current speed of the low-pressure rotors, and the current acceleration rate of the low-pressure rotors are determined in real time.

[0044] like Figure 4 As shown in the embodiment of this application, a schematic diagram of key phase synchronization sampling is provided. The "high-pressure keyway" of the high-pressure rotor and the "low-pressure keyway" of the low-pressure rotor are two physical marker points, which serve as "marker points" for speed detection. When the rotor rotates, the keyway triggers the sensor to generate a "key phase signal" (pulse signal). The dual-key phase signal synchronization analysis module is the core functional module of signal processing, which is responsible for synchronously acquiring the key phase signals of the two rotors. The SSS clutch is the connecting component of the two rotors, and its engagement depends on the synchronization of the speed and angle of the two rotors.

[0045] In step A1, the "angle difference between the low-pressure rotor keyway rotating in the rotation direction to the same radial position of the high-pressure rotor keyway" can be defined as the meshing angle θ (0°~359°). In some specific examples, step A1 can realize the implementation process from signal acquisition to parameter calculation as follows: A11. Synchronous acquisition of key phase signals: The sensors detect the keyways of the high-pressure and medium-pressure rotors and the low-pressure rotors respectively. When the keyway passes the sensor, it outputs the corresponding key phase signal. The "dual key phase signal synchronous analysis module" captures these two signals at the same time to ensure the time synchronization of the acquisition.

[0046] A12. Calculate the engagement angle θ: By comparing the trigger time difference of the two key phase signals and combining the rotor angular velocity, the "angle difference between the low-pressure rotor keyway and the same radial position of the high-pressure rotor keyway" can be calculated, that is, the engagement angle θ (directly corresponding to the current engagement position of the SSS clutch).

[0047] A13. Obtain rotor operating parameters: Based on the pulse frequency of the key phase signal, calculate the angular velocity (i.e., rotational speed) of the high-pressure and low-pressure rotors; by continuously collecting rotational speed data, further calculate the angular acceleration (i.e., acceleration rate) of the low-pressure rotor.

[0048] In step A1 above, key parameters such as engagement angle θ, rotor speed, and acceleration rate are acquired in real time by synchronously acquiring key phase signals. This provides accurate input data for subsequent feedforward-feedback composite control, ensuring that the clutch can complete engagement at the target angle.

[0049] A2. Using the current speed of the high-pressure rotor, the current speed of the low-pressure rotor, and the current acceleration rate of the low-pressure rotor, predict the predicted meshing angle between the low-pressure rotor cogs and the high-pressure rotor cogs when the speed of the low-pressure rotor is synchronized with that of the high-pressure rotor, and use this as the prediction data obtained by feedforward control.

[0050] Step A2 calculates the angle at which engagement is achieved when accelerating at the current rate of increase, providing a benchmark for subsequent deviation determination. This can be further refined to include the following implementation steps: A21. Calculate the time ΔT1 required for the low-pressure rotor speed to synchronize with the high-pressure rotor speed (V2=V1) from the current time K, using the following formula (1): Where V2 is the current speed of the low-pressure rotor, and V1 is the speed of the intermediate-pressure rotor. It is the current acceleration rate. The time required for synchronization is obtained by dividing the speed difference by the acceleration rate.

[0051] A22. Calculate the phase change of the low-pressure rotor relative to the high-pressure rotor within the time interval ΔT1. The essence is to obtain the change in the angle difference between the two rotors by integrating the speed difference, thus providing a basis for predicting the final meshing angle. Specifically, it is achieved using the following formula (2): The variables appearing in this formula (2) will not be further explained.

[0052] A23. Calculate the predicted engagement angle at the final engagement point. Specifically, this is achieved using the following formula (3): ;in It is the current engagement phase difference at time K, plus the phase change within ΔT1. This yields the predicted value of the final meshing angle.

[0053] A3. Based on the deviation between the predicted engagement angle and the preset target engagement angle, determine whether it is necessary to adjust the current acceleration rate corresponding to the low-pressure rotor, and use this as the deviation judgment result obtained from the feedback control.

[0054] In some specific instances, step A3 specifically involves: determining whether the deviation between the predicted meshing angle and the preset target meshing angle exceeds the preset deviation range; if yes, then determining that the current acceleration rate corresponding to the low-pressure rotor needs to be adjusted; if no, then determining that the current acceleration rate corresponding to the low-pressure rotor does not need to be adjusted.

[0055] Specifically, the deviation value is obtained by comparing the "predicted engagement angle" with the "target engagement angle" and used as the basis for whether the acceleration rate needs to be adjusted. Specifically, the following formula (4) is used: ; Calculate the "target engagement angle" With the predicted meshing angle deviation If the deviation is 0, it means that the current rate of ascent is just enough to allow the meshing angle to precisely match the target; if the deviation is not 0, the rate of ascent needs to be adjusted.

[0056] A4. If it is determined that the current lift rate corresponding to the low-pressure rotor needs to be adjusted, the current lift rate corresponding to the low-pressure rotor is adjusted according to the deviation judgment result obtained from the feedback control to obtain a new lift rate. Then, based on the new lift rate, the feedforward control is repeatedly executed to obtain new predicted data, and the feedback control is repeatedly executed using the new predicted data to obtain a new deviation judgment result, which is used to determine whether the new lift rate needs to be adjusted again. The feedforward control and feedback control are iteratively executed until it is determined that no adjustment operation needs to be performed.

[0057] As mentioned above, step A2 serves as the "prediction stage" of feedforward control, step A3 serves as the "deviation determination stage" of feedback control, and this step A4 serves as the "adjustment stage" of the feedforward-feedback composite control, utilizing a "target engagement angle". With the predicted meshing angle deviation The allowable range of "" is used as a constraint condition. Based on the deviation judgment result, it is determined whether to adjust the acceleration rate to ensure that the final actual meshing angle accurately matches the target. Specifically, it is achieved using the following formula (5): Set an "allowable threshold" for the deviation. If the absolute value of the deviation is ≤5, it means that the current acceleration rate meets the requirements for precise meshing and no adjustment is needed. If the deviation exceeds the threshold, the output frequency and torque of the variable frequency motor are dynamically adjusted through a feedforward-feedback algorithm to change the acceleration rate of the low-voltage rotor. Then repeat steps A2 and A3 to re-predict and recalculate the deviation until the deviation meets the threshold requirement.

[0058] In step 102, A1-A4 are provided to realize the core of the entire process: "prediction in advance → deviation calculation → dynamic adjustment". By combining feedforward control (predicting angle) and feedback control (correcting deviation), the acceleration rate of the low-pressure rotor is always in the optimal state, which ultimately ensures that the subsequent SSS clutch completes precise engagement at the target angle.

[0059] Step 103: If the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within the second preset threshold, it is determined that the SSS clutch tooth groove has completed fixed-point meshing.

[0060] In this embodiment of the application, based on the processing of "making the real-time relative meshing angle between the low-pressure rotor and the high-pressure rotor gradually approach the preset target meshing angle" achieved in step 102 (i.e., feedforward-feedback composite control further reduces the adjustment error), when the low-pressure rotor and the high-pressure rotor are at synchronous speed (e.g., the speed is close to 3000 r / min), and ensuring that the deviation between the real-time relative meshing angle and the target meshing angle converges to within a certain preset threshold (e.g., ±2°), it can be determined that the tooth groove of the SSS clutch is meshing in the optimal region.

[0061] Step 104: After confirming that the SSS clutch has completed the fixed-point engagement, trigger the locking mechanism to fix the SSS clutch and stop the variable frequency motor.

[0062] Step 105: By gradually controlling the opening of the low-pressure cylinder intake valve to full opening, the steam entering the low-pressure cylinder is used to drive the low-pressure cylinder to operate under load, thus completing the switching of the heating mode of the heating unit.

[0063] As shown in steps 104-105, after the SSS clutch engages, its built-in locking mechanism is immediately triggered to mechanically lock the clutch and prevent accidental disengagement. Simultaneously, the variable frequency motor stops operating (at this point, the motor's output power is zero, and it is out of the power system). Then, the low-pressure cylinder inlet valve is opened, allowing steam to enter the low-pressure cylinder. The steam drives the variable frequency motor as the main power source for the low-pressure rotor, and the low-pressure cylinder begins to bear the load and perform work. At this point, the heating unit officially switches to extraction-condensing heating mode, completing the entire transition from back pressure to extraction-condensing operation.

[0064] The core objective of this stage is to achieve a smooth switch of power source: from "variable frequency motor drive" to "steam drive", so that the low-pressure cylinder can be restored to normal operation under conventional thermodynamic cycle.

[0065] Furthermore, as a response to the above Figure 1 The present application provides a fixed-point engagement control device for an NCB turbine SSS clutch, illustrating the method described and further providing some specific examples. This device embodiment corresponds to the aforementioned method embodiment. For ease of reading, this device embodiment will not repeat the details of the aforementioned method embodiment, but it should be understood that the device in this embodiment can implement all the contents of the aforementioned method embodiment. This device provides a practical solution for the fixed-point engagement control of the SSS clutch, specifically as follows... Figure 5 As shown, the device includes: The starting unit 21 is used to start the variable frequency motor connected to the free end of the low-pressure rotor when the heating network load decreases and the heating unit needs to switch from back pressure heating mode to extraction condensing heating mode. The variable frequency motor is used to directly drive the low-pressure rotor to speed up and rotate through mechanical connection. The first monitoring unit 22 is used to monitor whether the rotational speed of the low-voltage rotor reaches a first preset threshold during the process of driving the low-voltage rotor to accelerate according to a preset speed-up curve by means of the power source provided by the variable frequency motor. The processing unit 23 is used to activate a composite control strategy combining preset feedforward and feedback if the speed of the low-pressure rotor is detected to reach a first preset threshold, so that the real-time relative meshing angle between the low-pressure rotor and the intermediate-pressure rotor gradually approaches the preset target meshing angle; wherein the intermediate-pressure rotor and the low-pressure rotor are arranged on separate shafts, and after the heating unit completes the switch from the back pressure heating mode to the extraction condensation heating mode, the intermediate-pressure rotor transmits power to the low-pressure rotor through the SSS clutch to drive the low-pressure cylinder to operate under load; The second monitoring unit 24 is used to monitor whether the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within a second preset threshold. The first determining unit 25 is used to determine that the SSS clutch tooth groove has completed fixed-point engagement if the deviation is detected to converge to within the second preset threshold. The first execution unit 26 is used to trigger the locking mechanism to fix the SSS clutch and stop the variable frequency motor after determining that the SSS clutch has completed the fixed-point engagement; The second execution unit 27 is used to gradually control the opening of the low-pressure cylinder intake valve to fully open, and use the steam entering the low-pressure cylinder to drive the low-pressure cylinder to operate under load, thereby completing the switching of the heating mode of the heating unit.

[0066] Furthermore, such as Figure 6 As shown, during the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, the device further includes: Control unit 28 is used to control the opening degree of the low-pressure cylinder inlet butterfly valve to reach a first preset opening degree, and to control the introduction of a first preset amount of steam into the low-pressure cylinder for cooling the low-pressure cylinder blades. The second determining unit 29 is used to utilize the controllable mechanical power provided by the variable frequency motor as the sole power source to drive the low-voltage rotor to accelerate and rotate.

[0067] Furthermore, such as Figure 6 As shown, during the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, the device further includes: The control unit 28 is also used to control the low-pressure cylinder to be supplied with a second preset amount of steam by controlling the low-pressure cylinder steam inlet butterfly valve from the first preset opening degree to the second preset opening degree; The second determining unit 29 is also used to use the controllable mechanical power provided by the variable frequency motor as the active power source, and the thermal drive formed by the amount of steam entering the low-pressure cylinder as the auxiliary power source. The second determining unit 29 is also used to drive the low-pressure rotor to accelerate and rotate based on the active power source and the auxiliary power source.

[0068] Furthermore, such as Figure 6 As shown, during the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, if the speed of the low-voltage rotor is detected to reach a first preset threshold, then the processing unit 23 is specifically used for: The calculation module 231 is used to determine the current speed of the high-pressure rotor, the current speed of the low-pressure rotor, and the current acceleration rate of the low-pressure rotor in real time based on the synchronously acquired high-pressure rotor key phase signal and low-pressure rotor key phase signal. The feedforward processing module 232 is used to predict the predicted meshing angle between the low-pressure rotor tooth slot and the high-pressure rotor tooth slot when the low-pressure rotor speed is synchronized with the high-pressure rotor speed, the current speed of the low-pressure rotor, and the current acceleration rate of the low-pressure rotor, and use it as the predicted data obtained by the feedforward control. The feedback processing module 233 is used to determine whether it is necessary to adjust the current acceleration rate corresponding to the low-pressure rotor based on the deviation between the predicted meshing angle and the preset target meshing angle, and use the deviation judgment result obtained by the feedback control as the result of the deviation judgment. The adjustment module 234 is used to, if it is determined that the current lifting rate corresponding to the low-pressure rotor needs to be adjusted, adjust the current lifting rate corresponding to the low-pressure rotor according to the deviation judgment result obtained by the feedback control to obtain a new lifting rate, and then repeatedly execute feedforward control based on the new lifting rate to obtain new predicted data, and use the new predicted data to repeatedly execute feedback control to obtain a new deviation judgment result, so as to determine whether the new lifting rate needs to be adjusted again, and iteratively execute feedforward control and feedback control until it is determined that no adjustment operation needs to be performed.

[0069] Furthermore, the feedback processing module 233 is specifically used to: determine whether the deviation between the predicted engagement angle and the preset target engagement angle exceeds a preset deviation range; if yes, determine that the current acceleration rate corresponding to the low-pressure rotor needs to be adjusted; if no, determine that the current acceleration rate corresponding to the low-pressure rotor does not need to be adjusted. In summary, the NCB turbine SSS clutch fixed-point engagement control device provided in this application includes a processor and a memory. The aforementioned starting unit, first monitoring unit, processing unit, second monitoring unit, determining unit, first execution unit, and second execution unit are all stored in the memory as program units. The processor executes the aforementioned program units stored in the memory to realize the corresponding functions.

[0070] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured. By adjusting kernel parameters, when the heating network load decreases and the heating unit needs to switch from back-pressure heating mode back to extraction-condensing heating mode, a controllable power source can be introduced as the primary power source, or its power function can be completely replaced when the steam intake of the low-pressure cylinder is insufficient to provide effective driving force. This significantly improves the control accuracy of the low-pressure rotor's acceleration curve, thus providing effective technical support for achieving the fixed-point engagement of the SSS clutch, and providing a practical solution for the fixed-point engagement control of the SSS clutch.

[0071] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the NCB turbine SSS clutch fixed-point engagement control method as described above.

[0072] This application also provides an electronic device, which includes at least one processor, at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute the NCB turbine SSS clutch fixed-point engagement control method as described above.

[0073] This application also provides a computer program product that, when executed on a data processing device, is suitable for executing a program that initializes the steps of the fixed-point engagement control method for the SSS clutch of an NCB steam turbine.

[0074] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] In a typical configuration, the device includes one or more processors (CPUs), memory, and a bus. The device may also include input / output interfaces, network interfaces, etc.

[0076] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM, and memory includes at least one memory chip. Memory is an example of computer-readable media.

[0077] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0078] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0079] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for fixed-point engagement control of the SSS clutch in an NCB steam turbine, applied to a distributed control system for NCB steam turbine operating condition switching control, characterized in that, The method includes: When the heating network load decreases and the heating unit needs to switch from back pressure heating mode back to extraction condensing heating mode, the variable frequency motor connected to the free end of the low-pressure rotor is started. The variable frequency motor is used to directly drive the low-pressure rotor to speed up and rotate through mechanical connection. During the process of using the power source provided by the variable frequency motor to drive the low-pressure rotor to accelerate according to the preset speed-up curve, if the speed of the low-pressure rotor is detected to reach the first preset threshold, a composite control strategy combining preset feedforward and feedback is activated for processing, so that the real-time relative meshing angle between the low-pressure rotor and the intermediate-high pressure rotor gradually approaches the preset target meshing angle; wherein, the intermediate-high pressure rotor and the low-pressure rotor are arranged on separate shafts, and after the heating unit completes the switch from the back pressure heating mode to the extraction condensation heating mode, the intermediate-high pressure rotor transmits power to the low-pressure rotor through the SSS clutch to drive the low-pressure cylinder to operate under load; If the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within the second preset threshold, it is determined that the SSS clutch tooth groove has completed fixed-point meshing. After confirming that the SSS clutch has completed the fixed-point engagement, the locking mechanism is triggered to fix the SSS clutch and stop the variable frequency motor; By gradually controlling the opening of the low-pressure cylinder intake valve to full opening, the steam entering the low-pressure cylinder is used to drive the low-pressure cylinder to operate under load, thereby completing the switching of the heating mode of the heating unit.

2. The method according to claim 1, characterized in that, In the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, the method further includes: By controlling the opening degree of the low-pressure cylinder inlet butterfly valve to reach the first preset opening degree, the first preset amount of steam is controlled to be introduced into the low-pressure cylinder to cool the low-pressure cylinder blades. The controllable mechanical power provided by the variable frequency motor is used as the sole power source to drive the low-voltage rotor to accelerate and rotate.

3. The method according to claim 2, characterized in that, In the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, the method further includes: By controlling the steam inlet butterfly valve of the low-pressure cylinder from the first preset opening degree to the second preset opening degree, the second preset amount of steam is controlled to be introduced into the low-pressure cylinder; The controllable mechanical power provided by the variable frequency motor is used as the active power source, and the thermal drive formed by the amount of steam entering the low-pressure cylinder is used as the auxiliary power source. Based on the active power source and the auxiliary power source, the low-pressure rotor is driven to accelerate and rotate.

4. The method according to any one of claims 1 to 3, characterized in that, During the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, if the speed of the low-voltage rotor is detected to reach a first preset threshold, a composite control strategy combining preset feedforward and feedback is activated to process the situation, so that the real-time relative meshing angle of the two rotors gradually approaches the preset target meshing angle, including: Based on the synchronously acquired key phase signals of the high-pressure and medium-pressure rotors and the low-pressure rotor, the current speed of the high-pressure and medium-pressure rotors, the current speed of the low-pressure rotors, and the current acceleration rate of the low-pressure rotors are determined in real time. Using the current speed of the high-pressure rotor, the current speed of the low-pressure rotor, and the current rate of increase of the low-pressure rotor, the predicted meshing angle between the low-pressure rotor tooth slots and the high-pressure rotor tooth slots is predicted when the speed of the low-pressure rotor is synchronized with that of the high-pressure rotor, and this prediction is used as the prediction data obtained by feedforward control. Based on the deviation between the predicted engagement angle and the preset target engagement angle, it is determined whether the current acceleration rate corresponding to the low-pressure rotor needs to be adjusted, which is used as the deviation judgment result obtained by feedback control. If so, based on the deviation judgment result obtained from the feedback control, the current lifting rate corresponding to the low-pressure rotor is adjusted to obtain a new lifting rate. Then, based on the new lifting rate, feedforward control is repeatedly executed to obtain new predicted data. The new predicted data is then used to repeatedly execute feedback control to obtain a new deviation judgment result, which is used to determine whether the new lifting rate needs to be adjusted again. Feedforward control and feedback control are iteratively executed until it is determined that no adjustment operation needs to be performed.

5. The method according to claim 4, characterized in that, The step of determining whether to adjust the current acceleration rate corresponding to the low-pressure rotor based on the deviation between the predicted engagement angle and the preset target engagement angle, as the deviation judgment result of the feedback control, includes: Determine whether the deviation between the predicted engagement angle and the preset target engagement angle exceeds a preset deviation range; If so, then it is determined that the current rate of increase corresponding to the low-pressure rotor needs to be adjusted; If not, then it is determined that there is no need to adjust the current rate of increase corresponding to the low-pressure rotor.

6. A fixed-point engagement control device for an NCB turbine SSS clutch, the device comprising: The starting unit is used to start the variable frequency motor connected to the free end of the low-pressure rotor when the heating network load decreases and the heating unit needs to switch from back pressure heating mode to extraction condensing heating mode. The variable frequency motor is used to directly drive the low-pressure rotor to accelerate and rotate through mechanical connection. The first monitoring unit is used to monitor whether the rotational speed of the low-voltage rotor reaches a first preset threshold during the process of driving the low-voltage rotor to accelerate according to a preset speed-up curve using the power source provided by the variable frequency motor. The processing unit is used to activate a composite control strategy combining preset feedforward and feedback if the speed of the low-pressure rotor is detected to reach a first preset threshold, so that the real-time relative meshing angle between the low-pressure rotor and the intermediate-pressure rotor gradually approaches the preset target meshing angle; wherein the intermediate-pressure rotor and the low-pressure rotor are arranged on separate shafts, and after the heating unit completes the switch from the back pressure heating mode to the extraction condensation heating mode, the intermediate-pressure rotor transmits power to the low-pressure rotor through the SSS clutch to drive the low-pressure cylinder to operate under load; The second monitoring unit is used to monitor whether the deviation between the real-time relative meshing angle of the low-pressure rotor and the high-pressure rotor and the target meshing angle converges to within a second preset threshold. The first determining unit is used to determine that the SSS clutch tooth groove has completed fixed-point engagement if the deviation is detected to converge to within the second preset threshold. The first execution unit is used to trigger the locking mechanism to fix the SSS clutch and stop the variable frequency motor after determining that the SSS clutch has completed the fixed-point engagement; The second execution unit is used to gradually control the opening of the low-pressure cylinder intake valve to fully open, and use the steam entering the low-pressure cylinder to drive the low-pressure cylinder to operate under load, thereby completing the switching of the heating mode of the heating unit.

7. The method according to claim 6, characterized in that, During the process of using the power source provided by the variable frequency motor to drive the low-voltage rotor to accelerate according to a preset speed-up curve, if the speed of the low-voltage rotor is detected to reach a first preset threshold, the processing unit is specifically used for: The calculation module is used to determine the current speed of the high-pressure rotor, the current speed of the low-pressure rotor, and the current acceleration rate of the low-pressure rotor in real time based on the synchronously acquired key phase signals of the high-pressure rotor and the low-pressure rotor. The feedforward processing module is used to predict the predicted meshing angle between the low-pressure rotor tooth slots and the high-pressure rotor tooth slots when the low-pressure rotor speed is synchronized with the high-pressure rotor speed, the current speed of the low-pressure rotor, and the current rate of increase of the low-pressure rotor, and use this as the predicted data obtained by the feedforward control. The feedback processing module is used to determine whether it is necessary to adjust the current acceleration rate corresponding to the low-pressure rotor based on the deviation between the predicted meshing angle and the preset target meshing angle, and use the deviation judgment result obtained from the feedback control as the result of the deviation judgment. The adjustment module is used to, if it is determined that the current rise rate corresponding to the low-pressure rotor needs to be adjusted, adjust the current rise rate corresponding to the low-pressure rotor according to the deviation judgment result obtained by the feedback control to obtain a new rise rate, and then repeatedly execute feedforward control based on the new rise rate to obtain new predicted data, and use the new predicted data to repeatedly execute feedback control to obtain a new deviation judgment result, so as to determine whether the new rise rate needs to be adjusted again, and iteratively execute feedforward control and feedback control until it is determined that no adjustment operation needs to be performed.

8. The method according to claim 7, characterized in that, The feedback processing module is specifically used for: Determine whether the deviation between the predicted engagement angle and the preset target engagement angle exceeds a preset deviation range; If so, then it is determined that the current rate of increase corresponding to the low-pressure rotor needs to be adjusted; If not, then it is determined that there is no need to adjust the current rate of increase corresponding to the low-pressure rotor.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the NCB turbine SSS clutch fixed-point engagement control method as described in any one of claims 1-5.

10. An electronic device, characterized in that, The device includes at least one processor, and at least one memory and bus connected to the processor; The processor and the memory communicate with each other via the bus. The processor is used to call program instructions in the memory to execute the NCB turbine SSS clutch fixed-point engagement control method as described in any one of claims 1-5.

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