A method and related device for controlling power oscillations in a turbine generator set.

Abstract

This invention discloses a method and related apparatus for controlling power oscillations in a turbine generator set, relating to the field of generator technology. The method includes: calculating the target working fluid flow rate of the turbine generator set to be controlled based on its operating parameters; determining the target total valve position corresponding to the target working fluid flow rate through iterative calculation based on a pre-calibrated valve flow characteristic function and valve management curve; setting a high limit and a low limit value for the target total valve position, centered on the target total valve position, to form a valve position limit range; and monitoring the current total valve position in real time when power oscillations occur in the turbine generator set to be controlled. If the current total valve position exceeds the valve position limit range, the change in the current total valve position is restricted, ensuring that the current total valve position operates within the valve position limit range, thereby limiting the change in the valve opening. This invention solves the problem that existing technologies cannot effectively suppress power oscillations caused by DEH parameters and valve management curve issues.

Description

Technical Field

[0001] This invention relates to the field of generator technology, and in particular to a method and related apparatus for controlling power oscillations in a turbine generator set. Background Technology

[0002] Power oscillation is a common and harmful phenomenon during the operation of turbine generator sets (including steam turbine sets and compressed air energy storage expander generator sets). Power oscillation manifests as periodic fluctuations in the unit's output power, which not only reduces power generation efficiency but also subjectes the equipment to additional alternating mechanical stress, accelerates component fatigue damage, shortens equipment lifespan, and in severe cases, even threatens the safe and stable operation of the power grid.

[0003] Currently, power control of turbine generator sets mainly relies on the power regulation loop in a digital electro-hydraulic control system (DEH) or coordinated control system (CCS). By setting a target power value, the controller outputs a total valve position command, which is then converted into the opening degree of each regulating valve via a valve management curve to change the flow rate of the working fluid entering the turbine, ultimately achieving closed-loop power regulation.

[0004] However, in practical engineering applications, existing control methods still have the following problems: First, the DEH parameter settings are unreasonable: when the control parameters (such as torque coefficient, integral time, etc.) in the DEH power regulation loop are not properly tuned, the response of the regulating valve to power deviation may be too slow or too drastic, causing the valve opening to repeatedly overshoot near the target value, thus triggering continuous power oscillations. Second, the valve management curve is unreasonable: the valve management curve determines the mapping relationship between the total valve position and the opening of each regulating valve. If the curve is poorly designed, such as excessive valve overlap, unreasonable dead zone setting, or poor linearization of flow characteristics, it will cause a nonlinear mismatch between the working fluid flow and power demand, which will also induce power oscillations.

[0005] The power oscillations caused by the aforementioned problems are difficult to completely eliminate through conventional PID parameter tuning or local correction of valve curves. Therefore, there is an urgent need for a control method that can effectively suppress power oscillations caused by DEH parameters and valve management curves, in order to improve unit operation stability and grid security. Summary of the Invention

[0006] This invention provides a method and related device for controlling power oscillations in turbine generator sets, which solves the problem that existing technologies cannot effectively suppress power oscillations caused by DEH parameters and valve management curves.

[0007] In view of this, the first aspect of the present invention provides a method for controlling power oscillations in a turbine generator set, the method comprising:

[0008] Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0009] Based on the pre-calibrated valve flow characteristic function and valve management curve, the target total valve position corresponding to the target working fluid flow rate is determined through iterative calculation;

[0010] Centered on the target main valve position, set the high limit and low limit of the target main valve position to form a valve position limit range;

[0011] When the power oscillation of the turbine generator set to be controlled occurs, the current total valve position is monitored in real time. If the current total valve position exceeds the valve position limit range, the change of the current total valve position is restricted so that the current total valve position operates within the valve position limit range. In turn, the change of the valve opening is restricted by the mapping relationship between the total valve position and the valve opening in the valve management curve.

[0012] Optionally, the calculation of the target working fluid flow rate of the turbine generator set under control based on the operating parameters of the turbine generator set under control includes:

[0013] Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0014] The formula for calculating the target working fluid flow rate is as follows:

[0015] ;

[0016] In the formula, The target working fluid flow rate, This refers to the target power value in a digital electro-hydraulic control system or coordinated control system. To control the temperature of the turbine generator set, To control the pressure of the turbine generator set, To control the turbine efficiency of the turbine generator set, To control the generator efficiency of the turbine generator set, To determine the specific enthalpy of the working fluid at the inlet of the turbine generator set to be controlled. The specific enthalpy is the working fluid at the outlet of the turbine generator set to be controlled.

[0017] Optionally, determining the target total valve position corresponding to the target working fluid flow rate through iterative calculation based on a pre-calibrated valve flow characteristic function and valve management curve includes:

[0018] S21. Assuming a master valve position and using it as the current master valve position, obtain the opening degree of each regulating valve according to the valve management curve;

[0019] S22. Calculate the working fluid flow rate of each valve and sum them up to obtain the total working fluid flow rate using the valve flow characteristic function and the opening degree of each valve.

[0020] S23. Compare the total working fluid flow rate with the target working fluid flow rate. If the difference does not meet the convergence condition, update the total valve position using the bisection method and return it to S21 as the current total valve position until the convergence condition is met. Then, determine the corresponding total valve position as the target total valve position.

[0021] Optionally, assuming a master valve position and using it as the current master valve position, and obtaining the opening degree of each regulating valve according to the valve management curve, includes:

[0022] When the valve management curve is a valve management curve under the sequential valve mode, the valves in the open state and their corresponding opening values ​​are obtained by looking up the table according to the current total valve position, so as to obtain the opening of each valve.

[0023] Optionally, the step of assuming a master valve position and using it as the current master valve position, and obtaining the opening degree of each regulating valve according to the valve management curve, further includes:

[0024] When the valve management curve is a valve management curve under single valve mode, a unified valve opening value is obtained by looking up the table according to the current total valve position, and the opening of each valve is taken from the unified valve opening value to obtain the opening of each valve.

[0025] Optionally, updating the total valve position using the binary search method includes:

[0026] Set initial upper and lower boundaries, and calculate the average value of the upper and lower boundaries;

[0027] The total working fluid flow rate is calculated based on the average value. If the total working fluid flow rate is greater than the target working fluid flow rate, the average value is used as the new upper boundary; otherwise, the average value is used as the new lower boundary.

[0028] Optionally, setting a high limit and a low limit of the target total valve position, centered on the target total valve position, to form a valve position limit range includes:

[0029] The target total valve position is increased by a preset percentage as the upper limit value, and the target total valve position is decreased by the preset percentage as the lower limit value.

[0030] A second aspect of the present invention provides a control system for power oscillation of a turbine generator set, the system comprising:

[0031] The calculation unit is used to calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0032] The iterative unit is used to determine the target total valve position corresponding to the target working fluid flow rate by iterative calculation based on the pre-calibrated valve flow characteristic function and valve management curve.

[0033] The setting unit is used to set the high limit and low limit of the target total valve position as the center, thereby forming a valve position limit range;

[0034] The control unit is used to monitor the current total valve position in real time when the power oscillation of the turbine generator set to be controlled occurs. If the current total valve position exceeds the valve position limit range, the change of the current total valve position is restricted so that the current total valve position operates within the valve position limit range. In turn, the change of the valve opening is restricted by the mapping relationship between the total valve position and the valve opening in the valve management curve.

[0035] A third aspect of the present invention provides a control device for power oscillation of a turbine generator set, the device comprising a processor and a memory:

[0036] The memory is used to store program code and transmit the program code to the processor;

[0037] The processor is configured to execute, according to the instructions in the program code, the steps of the control method for power oscillation of a turbine generator set as described in the first aspect above.

[0038] A fourth aspect of the present invention provides a computer-readable storage medium for storing program code for executing the control method for power oscillation of a turbine generator set described in the first aspect above.

[0039] As can be seen from the above technical solutions, the present invention has the following advantages:

[0040] In summary, the power oscillation control method for a turbine generator set provided in this embodiment of the invention first calculates the target working fluid flow rate of the turbine generator set to be controlled based on its operating parameters, thus eliminating the root cause of nonlinear mismatch between power and valve opening from the source of energy conservation. Then, based on the pre-calibrated valve flow characteristic function and valve management curve, the target total valve position corresponding to the target working fluid flow rate is determined through iterative calculation. A bisection method is then used to rapidly approximate the true value within the monotonic interval of the total valve position and the total working fluid flow rate, effectively compensating for back-calculation errors caused by sequential valve overlap distortion or single-valve throttling nonlinearity, ensuring high precision of the target total valve position command. The invention addresses convergence efficiency. Next, using the target total valve position as the center, it sets high and low limits for the target total valve position, forming a valve position limit range. A rigid boundary layer is constructed using preset percentage symmetrical limits, providing a safe physical constraint range for valve action from the command source. Finally, when power oscillations occur in the controlled turbine generator unit, the current total valve position is monitored in real time. If the current total valve position exceeds the valve position limit range, changes in the current total valve position are restricted, ensuring it operates within the valve position limit range. This restricts valve opening changes, directly cutting off abnormal disturbances in working fluid flow caused by valve overshoot or fluctuations, and suppressing power fluctuation amplitude within allowable limits. Therefore, this invention not only significantly reduces power oscillation amplitude and improves unit operation stability and grid security, but also reduces alternating mechanical stress on equipment by avoiding frequent large-amplitude valve movements, thereby extending unit lifespan and reducing maintenance costs. This solves the problem that existing technologies cannot effectively suppress power oscillations caused by DEH parameters and valve management curve issues. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A flowchart illustrating a method for controlling power oscillations in a turbine generator set, provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the total valve position range provided in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of a control system for power oscillation of a turbine generator set, provided as an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Terminology Explanation:

[0047] DEH (Digital Electro-Hydraulic Control System) is a digital electro-hydraulic control system. "Electro-Hydraulic" refers to the conversion of electrical signals into hydraulic signals to drive valves. The DEH is the direct controller of the turbine generator set. Its core function is to control the unit's speed and load by adjusting the opening of the turbine's main steam valve and regulating valve. It also handles the unit's start-up, shutdown, normal operation, and protection during emergency conditions. In short, the DEH is a "local actuator controller" for the turbine generator set's own speed and power regulation.

[0048] CCS (Coordinated Control System) is a higher-level control system than DEH. It treats the boiler and turbine generator unit as a single unit for integrated control. By coordinating the energy supply and demand balance between the boiler side (fuel and feedwater) and the turbine side (valve opening), the unit can quickly respond to grid load demands while maintaining the stability of key parameters such as main steam pressure. In simpler terms, DEH manages "how the turbine turns," while CCS manages "how the boiler and turbine coordinate."

[0049] The relationship between DEH, CCS, and turbine generator sets: DEH is the control system at the direct execution level, while CCS is the control system at the coordination and command level. In terms of operation, when the unit is in CCS mode, the load control of the turbine generator set is uniformly dispatched by CCS. CCS issues valve position or power commands to DEH, which then converts the commands into specific valve opening signals and executes them. In scenarios involving power oscillation suppression, DEH's actions respond quickly to grid frequency fluctuations, while CCS achieves long-term stable power balance by correcting load setpoints. Efficient coordination between the two is essential to ensure the safe, stable, and economical operation of the turbine generator set.

[0050] Target working fluid flow rate: refers to the expected mass flow rate of the working fluid that must be supplied to meet the operating requirements in a thermodynamic cycle system (such as a steam turbine, gas turbine, compressed air energy storage expander, etc.), based on the set power output target or heat load demand, combined with the thermodynamic state parameters of the working fluid inlet and outlet and the unit's energy conversion efficiency, and calculated through the energy balance relationship.

[0051] Target total valve position: In a turbine generator set control system, this refers to the expected total opening of the regulating valves, calculated by the upper-level control loop and output as a command to meet specific operational requirements (such as target load or target working fluid flow). From the perspective of the control system's hierarchy, the target total valve position is a comprehensive command signal. It does not directly correspond to the physical opening of any specific valve, but rather characterizes the overall throttling degree or energy input level that all participating valves should collectively achieve. This signal is usually expressed as a percentage (0% to 100%) or a dimensionless per-unit value, and its magnitude determines the total flow capacity of the working fluid entering the turbine.

[0052] Valve opening: refers to the degree of travel displacement of the valve core of each regulating valve relative to the fully closed position in the steam (gas) intake system of a turbine (steam turbine or gas turbine). It is usually expressed as a percentage (0% corresponds to fully closed, 100% corresponds to fully open) or a specific travel distance (such as millimeters).

[0053] From a fluid mechanics perspective, the valve opening directly determines the size of the flow cross-sectional area at the valve throat, thus affecting the mass flow rate of the working fluid passing through the valve. It is the physical quantity at the execution end that converts the electrical command signals of the control system into mechanical displacement via an electro-hydraulic conversion mechanism, and is also a key interface parameter connecting the unit's automatic control loop and the thermodynamic process of the working fluid. During operation, the size of the valve opening and its rate of change directly affect the flow rate of the working fluid entering the turbine, thereby regulating the unit's output power and speed.

[0054] Valve management curves, in the context of turbine generator set control systems, are function curves or data tables used to define the mapping relationship between the main valve position and the control valve opening. From a control system architecture perspective, the valve management curve sits between the upper-level load / speed controller and the lower-level valve actuators, serving as a means of command parsing and allocation. Since turbines typically have multiple regulating valves, each undertaking different regulating tasks at different load stages, a single electrical control command (main valve position) cannot directly drive the coordinated action of multiple valves. The valve management curve is precisely the intermediate conversion link established to solve this "single command, multiple actuators" coordination problem.

[0055] The mapping relationship between the total valve position and the control valve opening refers to the corresponding rule for converting the total valve position command (usually expressed as a percentage or per unit value) output by the upper controller into the actual opening value of each control valve.

[0056] Example 1:

[0057] Please see Figure 1 The present invention provides a method for controlling power oscillations in a turbine generator set, comprising:

[0058] Step 101: Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled;

[0059] It should be noted that this step is based on the real-time operating parameters of the turbine generator set (such as the power target value in the digital electro-hydraulic control system or coordinated control system, the unit temperature, etc.) and is solved by the preset target working fluid flow calculation formula. This provides a quantitative basis for the subsequent determination of the target total valve position. The specific calculation method is described in the corresponding embodiment below.

[0060] Step 102: Based on the pre-calibrated valve flow characteristic function and valve management curve, determine the target total valve position corresponding to the target working fluid flow rate through iterative calculation;

[0061] It should be noted that this step is used to integrate the pre-calibrated valve flow characteristic function (see Examples 2 and 3) and valve management curve, and to accurately solve the target total valve position that matches the target working fluid flow through iterative calculation, thereby transforming the abstract flow requirement into specific valve control parameters. The specific process is shown in the corresponding examples below.

[0062] Step 103: Using the target total valve position as the center, set the high limit and low limit of the target total valve position to form a valve position limit range;

[0063] It should be noted that, assuming the calculated target total valve position is 50%, a valve position fluctuation range of ±5% is set with 50% as the center. That is, the upper limit is set to 55% and the lower limit is set to 45%, forming a valve position limit range of 45%-55%. This step limits the excessive change of the valve opening during power oscillation by dynamically defining the valve position adjustment boundary, avoiding the aggravation of system fluctuations due to frequent and large valve movements. At the same time, it provides a clear control threshold for subsequent opening limit, ensuring that the unit operates under stable conditions. The specific process is described in the corresponding embodiment below.

[0064] Step 104: When the power oscillation of the turbine generator set to be controlled occurs, monitor the current total valve position in real time. If the current total valve position exceeds the valve position limit range, restrict the change of the current total valve position so that the current total valve position operates within the valve position limit range. Then, limit the change of the valve opening through the mapping relationship between the total valve position and the valve opening in the valve management curve.

[0065] It should be noted that, specifically, when the turbine generator set experiences power oscillations due to DEH parameters or valve management curve issues (such as active power continuously fluctuating around the target value), the DEH system reads the current actual output total valve position value in real time with a sampling period of no less than 100ms / time. Assume that the target total valve position calculated through steps 101-103 is 50%, and the valve position limit range is set at ±5% (high limit 55%, low limit 45%).

[0066] Compare the current total valve position with this range:

[0067] If the current total valve position rises to 56% (exceeding 55%), the DEH will immediately clamp the total valve position command at 55% to prevent it from increasing further.

[0068] If the current total valve position drops to 44% (below 45%), then clamp it at 45% and prevent further reduction.

[0069] Since there is a definite valve management curve mapping relationship between the main valve position and the opening of each regulating valve (such as the lookup table opening sequence under the sequential valve mode), after limiting the current main valve position to operate within the range of [45%, 55%], the opening of each regulating valve is naturally limited to the corresponding safe opening range, thereby avoiding abnormal disturbances in the working fluid flow caused by overshooting or frequent fluctuations of the main valve position command, and effectively suppressing power oscillation.

[0070] In one embodiment, step 101 includes:

[0071] Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0072] The formula for calculating the target working fluid flow rate is as follows:

[0073] ;

[0074] In the formula, The target working fluid flow rate, This refers to the target power value in a digital electro-hydraulic control system (DEH) or coordinated control system (CCS). To control the temperature of the turbine generator set, To control the pressure of the turbine generator set, To control the turbine efficiency of the turbine generator set, To control the generator efficiency of the turbine generator set, To determine the specific enthalpy of the working fluid at the inlet of the turbine generator set to be controlled. The specific enthalpy is the working fluid at the outlet of the turbine generator set to be controlled.

[0075] It should be noted that, and The specific enthalpy at the inlet and outlet is determined using a high-precision enthalpy-entropy diagram. This does not refer to operators actually consulting a paper enthalpy-entropy diagram, but rather to a general technical description of the method for determining the state parameters of water and steam in engineering thermodynamics. The actual implementation is as follows: a thermodynamic property calculation module based on the IAPWS-IF97 industrial standard formula published by the International Association for the Properties of Water and Steam is built into the digital electro-hydraulic control system (DEH) or distributed control system (DCS) of the turbine generator set. When the high-precision temperature and pressure sensors installed in front of the main steam valve and the exhaust port transmit the real-time collected working fluid temperature and pressure signals to the control system, the module immediately calls the corresponding regional function, such as the function for superheated steam region, to perform calculations, thereby quickly and accurately returning the specific enthalpy value at that measuring point.

[0076] In this embodiment, firstly, based on the current operating conditions of the turbine generator set, key operating parameters such as the temperature and pressure of the working fluid and the power target value set in the digital electro-hydraulic control system or coordinated control system are acquired through sensors. Then, based on the first law of thermodynamics and the principle of energy conservation, the calculation formula for the target working fluid flow rate is invoked. The unit efficiency is used to characterize the loss factors in the energy conversion process, while the specific enthalpy difference reflects the actual work capacity of a unit of working fluid in the turbine, thereby converting the abstract electrical power target into a specific working fluid flow rate requirement. Next, the calculated value serves as the core input parameter for subsequent iterative solutions to the target total valve position. This allows the control strategy to bypass the overshoot problem caused by the nonlinear characteristics of the valve in traditional PID control, establishing a precise correspondence between power demand and valve action at the essential level of flow rate. This provides a crucial quantitative basis for forming an effective valve position limit range and suppressing power oscillations.

[0077] In one embodiment, step 102 includes:

[0078] Step 1021: Assume a master valve position and use it as the current master valve position. Based on the valve management curve, obtain the opening degree of each regulating valve.

[0079] It should be noted that after determining the target working fluid flow rate, in order to find the total valve position that precisely matches it, an initial total valve position value is first assumed and used as the input for the total valve position in the current iterative calculation, thus initiating the reverse solution process from valve position to flow rate. Then, based on the pre-tuned valve management curve and the established mapping relationship between the total valve position and the opening of each regulating valve, the system decomposes the assumed total valve position command into specific regulating valve opening values ​​by looking up tables or function interpolation. For example, if operating in sequential valve mode, different opening sequences of each valve are obtained; if operating in single valve mode, a uniform regulating valve opening is obtained. Next, this step concretizes the abstract total valve position, which represents the depth of the overall command, into a distribution of regulating valve openings that can directly act on the field actuators. It is not only the conversion hub connecting the upper-level flow demand and the lower-level valve action, but also provides accurate boundary conditions for subsequent calculation of the total working fluid flow rate by calling the valve flow characteristic function based on the opening of each regulating valve, ensuring that the iterative calculation can approach the target value along the actual valve configuration characteristics.

[0080] Step 1022: Calculate the working fluid flow rate of each valve and sum them up to obtain the total working fluid flow rate using the valve flow characteristic function and the opening degree of each valve.

[0081] It should be noted that after obtaining the opening degree of each control valve in step 1021, this step first takes each control valve in operation and substitutes its corresponding opening value as an independent variable into the valve flow characteristic function calibrated in advance through experiments to calculate the working fluid mass flow rate through that single control valve. This function determines the nonlinear correspondence between valve opening degree and flow capacity. Then, the single-valve working fluid flow rates calculated for all control valves (e.g., valves partially open in sequential valve mode and valves operating synchronously in single valve mode) are algebraically summed to obtain the total working fluid flow rate of the turbine steam (or air) system under the current assumed total valve position. Next, this total working fluid flow rate serves as a key feedback quantity in the iterative loop, providing a direct comparison standard for subsequent difference comparison with the target working fluid flow rate. This determines the direction and magnitude of the bisection search in subsequent steps, enabling the control algorithm to accurately backtrack to the actual total valve position command that meets the power requirements in the complex and nonlinear valve configuration characteristics. It can be understood that this step is the key step in mapping the physical action of the valve back to the flow effect.

[0082] Step 1023: Compare the total working fluid flow rate with the target working fluid flow rate. If the difference does not meet the convergence condition, update the total valve position using the binary search method and return to step 1021 as the current total valve position. Continue until the convergence condition is met, and then determine the corresponding total valve position as the target total valve position.

[0083] It should be noted that after obtaining the total working fluid flow rate corresponding to the current assumed total valve position in step 1022, this step first compares it numerically with the target working fluid flow rate calculated based on the power target in step 101, and calculates the difference between the two as an error criterion for measuring whether the current valve position command meets the load requirements; then, if the absolute value of the difference ( The convergence accuracy threshold is greater than the preset threshold (e.g.) ( ), (The total valve position is the rated flow rate of the unit). This indicates that the currently assumed total valve position fails to match the actual flow capacity of the unit with the power command. At this point, the total valve position is updated using a bisection method. By dynamically adjusting the upper or lower boundary of the search interval and taking the median as the new total valve position, the mathematical property of the bisection method to quickly approximate the true value within the monotonic interval is utilized, which significantly reduces the number of iterations under nonlinear valve characteristics and avoids oscillations and divergences caused by parameter mutations. Then, the updated total valve position is used as the current value to return to the valve opening acquisition stage, and the closed-loop iterative process of flow accumulation and comparison is repeated until the difference between the total working fluid flow rate and the target working fluid flow rate meets the preset convergence condition. At this point, the corresponding total valve position is the optimal command value that can accurately compensate for the unit efficiency deviation and valve nonlinear mismatch under the current operating conditions. This is determined as the target total valve position, providing a unique and reliable central reference for setting the valve position limit interval, and avoiding power overshoot and oscillation problems caused by unreasonable DEH parameters or valve management curves.

[0084] In one embodiment, step 1021 includes:

[0085] Step 10211: When the valve management curve is a valve management curve under the sequential valve mode, the valves in the open state and their corresponding opening values ​​are obtained by looking up the table according to the current total valve position, so as to obtain the opening degree of each valve.

[0086] It should be noted that when the unit operates in sequential valve mode, the valve management curve uses the total valve position as the horizontal axis and the opening degree of each control valve as the vertical axis. The opening sequence and overlap of each control valve are defined by a preset piecewise function, so that the control valves operate sequentially rather than synchronously. Then, based on the current assumed or actual output total valve position command, the valve management curve data under this sequential valve mode is accessed by looking up a table. From this, the control valves in the open state and their corresponding specific opening values ​​are directly obtained, thereby resolving the single total valve position signal into a discrete opening distribution of each control valve. This lookup mapping process then enables the control logic to accurately identify the specific valve channel into which the working fluid flows and its respective throttling degree.

[0087] Step 10212: When the valve management curve is a valve management curve under single valve mode, a unified valve opening value is obtained by looking up the table according to the current total valve position, and the opening of each valve is taken from the unified valve opening value to obtain the opening of each valve.

[0088] It should be noted that when the turbine generator set is operating in single-valve mode, the valve management curve sets the total valve position command and the opening degree of each regulating valve as a single linear or piecewise function mapping relationship. Then, in this mode, based on the current iteration assumption or the actual output total valve position value, the valve management curve data under this single-valve mode is accessed by looking up a table, and a unified regulating valve opening value is directly obtained from the table. This unified regulating valve opening value is then assigned to all regulating valves, meaning that the opening degree of each regulating valve takes the same value.

[0089] In one embodiment, step 1023, updating the total valve position using a binary search method, includes:

[0090] Set initial upper and lower boundaries, and calculate the average value of the upper and lower boundaries;

[0091] The total working fluid flow rate is calculated based on the average value. If the total working fluid flow rate is greater than the target working fluid flow rate, the average value is used as the new upper boundary; otherwise, the average value is used as the new lower boundary.

[0092] It should be noted that in the iterative solution of the target total valve position, an initial upper and lower boundary covering the possible range of the total valve position is first set, and the average value of the upper and lower boundaries is calculated. This average value is then used as the current total valve position and substituted into the subsequent flow calculation, thus providing an intermediate trial point for the search of nonlinear valve characteristics. Then, based on this current total valve position, the total working fluid flow rate is obtained by accumulating the valve management curve and the flow characteristic function of each regulating valve. This total working fluid flow rate is compared with the target working fluid flow rate: if the calculated total working fluid flow rate is greater than the target working fluid flow rate, then... If the current test valve position is too large, the average value is used as the new upper boundary to compress the high end of the search interval. Conversely, if the calculated total working fluid flow rate is less than or equal to the target working fluid flow rate, the test valve position is too small, and the average value is used as the new lower boundary to exclude the low end of the search interval. Then, the above median and boundary update operations are repeated, utilizing the inherent monotonically increasing relationship between the total valve position and the total working fluid flow rate to gradually shrink the search interval and quickly approach the true solution until the difference between the total working fluid flow rate and the target working fluid flow rate satisfies the preset convergence condition. This valve position update mechanism based on the bisection method effectively avoids the iterative divergence or slow convergence problems caused by the nonlinearity of the valve management curve, ensuring the efficiency and accuracy of the target total valve position calculation.

[0093] Note: Also known as the bisection search method or the binary search method, this is a classical numerical method for finding approximate roots of single-variable continuous function equations. Its basic principle is based on the Intermediate Value Theorem: for a function to be continuous and monotonic on a closed interval [a, b] (or at least have opposite signs at its two endpoints), the following formula is used: The function is used to divide the interval containing the root into two sub-intervals in each iteration, retaining the sub-interval where the function values ​​at the endpoints have opposite signs as the new search interval. By repeatedly performing the operations of "finding the midpoint, determining the sign, and shrinking the boundary," the range of the interval containing the root is gradually compressed until the interval length or function value is less than the preset tolerance. At this point, the midpoint of the interval can be used as an approximate solution to the equation. The significant characteristics of the bisection method are its simple algorithm structure, stable convergence behavior, and low requirement for the smoothness of the function. As long as the function is continuous within the interval and the two ends have opposite signs, it will definitely converge. Its convergence speed is linear, and each iteration can reduce the search interval by half. Therefore, in engineering calculations, it is often used for fast target value search in nonlinear mapping relationships that cannot be directly inverted or differentiated.

[0094] In one embodiment, step 103 includes:

[0095] The target total valve position is increased by a preset percentage as the upper limit value, and the target total valve position is decreased by the preset percentage as the lower limit value.

[0096] It should be noted that after accurately obtaining the target total valve position corresponding to the target working fluid flow rate through iterative calculation, the target total valve position is first used as the central reference value, and a preset percentage (e.g., ±5%) is added to it as the upper limit of the total valve position. At the same time, the target total valve position is reduced by the same preset percentage as the lower limit of the total valve position. Then, this combination of high and low thresholds forms a symmetrical and clear valve position limit range, which defines the boundary range for the valve action of the turbine generator set in real-time operation. Then, when power oscillation occurs, the valve opening change is monitored in real time. Once the valve opening attempts to exceed the valve position limit range due to unreasonable DEH parameters or valve management curve mismatch, the control logic will quickly limit the valve opening change and force it to operate within the high and low limits. This directly cuts off the abnormal disturbance of working fluid flow caused by valve overshoot or fluctuation, effectively suppressing the power oscillation amplitude from the mechanical execution level, and ensuring the stable operation of the unit near the target load and the safety of the power grid.

[0097] Example 2:

[0098] This embodiment is a specific implementation of steps 101 to 102 above (the valve management curve is a sequence valve method):

[0099] Taking a 300MW turbine generator unit as an example, its DEH system parameters and valve management curves are known. Assume the current target power is... The working fluid parameter is temperature. and pressure Turbine generator set efficiency Known.

[0100] Step 1, Initialize parameters: Obtain , , , Parameters, and initialize the assumed total valve position. (Current valve position or zero can be selected).

[0101] Step 2: Determine the target working fluid flow rate: According to the formula Calculate the target working fluid flow rate.

[0102] Step 3: Obtain the valve opening: Based on the valve management curve and the assumed main valve position. Look up the table to obtain the opening degree of each valve. .

[0103] Step 4: Calculate the working fluid flow rate: Calculate the working fluid flow rate of each valve using its flow characteristic function and valve opening. This is the "valve flow characteristic function", and the total working fluid flow rate is obtained by summing the results. .

[0104] Step 5: Comparison and Judgment: Calculate the difference between the total working fluid flow rate and the target working fluid flow rate. ,like ( ), This is the rated flow rate of the unit. Then output the current total valve position. Set the target master valve position; otherwise, proceed to the next step.

[0105] Step 6: Adjust the main valve position: Use the binary method to adjust the main valve position, and set the initial upper and lower boundaries. and (See also) Figure 2 Iterative calculation of intermediate points Calculate the total working fluid flow rate. ,like Then Otherwise, Repeat steps 3-5 until the convergence condition is met (i.e., ...). ( )).

[0106] Example 3:

[0107] This embodiment is a specific implementation of steps 101 to 102 above (the valve management curve is a single-valve mode):

[0108] Taking a 300MW turbine generator unit as an example, its DEH system parameters and valve management curves are known. Assume the current target power is... The working fluid parameter is temperature. and pressure Turbine generator set efficiency Known.

[0109] Step 1, Initialize parameters: Obtain , , , Parameters, and initialize the assumed total valve position. (Current valve position or zero can be selected).

[0110] Step 2: Determine the target working fluid flow rate: According to the formula Calculate the target working fluid flow rate. This involves using the saturated working fluid density formula. Enthalpy formula Calculate the working fluid density and enthalpy.

[0111] Step 3: Obtain the valve opening: In single-valve control mode, the openings of all valves are basically the same, that is... .

[0112] Step 4: Calculate the working fluid flow rate: Calculate the working fluid flow rate of each valve using its flow characteristic function and valve opening. And sum them up to get the total working fluid flow rate. .

[0113] Step 5: Comparison and Judgment: Calculate the difference between the total working fluid flow rate and the target working fluid flow rate. ,like ( ), This is the rated flow rate of the unit. Then output the current total valve position. Set the target master valve position; otherwise, proceed to the next step.

[0114] Step 6: Adjust the main valve position: Use the binary method to adjust the main valve position and set the initial upper and lower boundaries. and Iterative calculation of intermediate points Calculate the total working fluid flow rate. ,like Then Otherwise, Repeat steps 3-5 until the convergence condition is met.

[0115] In summary, the power oscillation control method for a turbine generator set provided in this embodiment of the invention first calculates the target working fluid flow rate of the turbine generator set based on its operating parameters. By real-time acquisition of working fluid temperature, pressure, and target power values, and combining the thermodynamic enthalpy difference formula, the abstract electrical power demand is accurately converted into a specific working fluid flow rate demand, thus eliminating the nonlinear mismatch between power and valve opening from the fundamental source of energy conservation. Then, based on the pre-calibrated valve flow characteristic function and valve management curve, the target total valve position corresponding to the target working fluid flow rate is determined through iterative calculation. A bisection method is then used to rapidly approximate the true value within the monotonic interval of the total valve position and the total working fluid flow rate, effectively compensating for distortions in the sequence valve overlap or single valve sections. The back-calculation error caused by flow nonlinearity ensures high accuracy and convergence efficiency of the target total valve position command. Next, with the target total valve position as the center, high and low limits are set to form a valve position limit range. A rigid boundary layer is constructed through preset percentage symmetrical limits, providing a safe physical constraint range for valve action from the command source. Finally, when power oscillations occur in the controlled turbine generator unit, the current total valve position is monitored in real time. If the current total valve position exceeds the valve position limit range, the change in the current total valve position is restricted, ensuring it operates within the valve position limit range. This restricts the valve opening change, directly cutting off abnormal disturbances in working fluid flow caused by valve overshoot or fluctuations, and suppressing power fluctuation amplitude within the allowable range. Therefore, this invention not only significantly reduces power oscillation amplitude and improves unit operation stability and grid security, but also reduces alternating mechanical stress on equipment by avoiding frequent large-amplitude valve movements, thereby extending unit life and reducing maintenance costs. This solves the problem that existing technologies cannot effectively suppress power oscillations caused by DEH parameters and valve management curve issues.

[0116] The above describes a control method for power oscillation of a turbine generator set provided in an embodiment of the present invention. The following describes a control system for power oscillation of a turbine generator set provided in an embodiment of the present invention.

[0117] Example 4:

[0118] Please see Figure 3 The present invention provides a control system for power oscillation of a turbine generator set, comprising:

[0119] Calculation unit 201 is used to calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0120] The iteration unit 202 is used to determine the target total valve position corresponding to the target working fluid flow rate by iterative calculation based on the pre-calibrated valve flow characteristic function and valve management curve.

[0121] Setting unit 203 is used to set the high limit value and low limit value of the target total valve position with the target total valve position as the center, to form a valve position limit range;

[0122] The control unit 204 is used to monitor the current total valve position in real time when the power oscillation of the turbine generator set to be controlled occurs. If the current total valve position exceeds the valve position limit range, the change of the current total valve position is restricted so that the current total valve position operates within the valve position limit range. In turn, the change of the valve opening is restricted by the mapping relationship between the total valve position and the valve opening in the valve management curve.

[0123] In one embodiment, the calculation unit 201 is specifically used for:

[0124] Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled.

[0125] The formula for calculating the target working fluid flow rate is as follows:

[0126] ;

[0127] In the formula, The target working fluid flow rate, This refers to the target power value in a digital electro-hydraulic control system or coordinated control system. To control the temperature of the turbine generator set, To control the pressure of the turbine generator set, To control the turbine efficiency of the turbine generator set, To control the generator efficiency of the turbine generator set, To determine the specific enthalpy of the working fluid at the inlet of the turbine generator set to be controlled. The specific enthalpy is the working fluid at the outlet of the turbine generator set to be controlled.

[0128] It should be noted that, and The specific enthalpy at the inlet and outlet is determined using a high-precision enthalpy-entropy diagram. This does not refer to operators actually consulting a paper enthalpy-entropy diagram, but rather to a general technical description of the method for determining the state parameters of water and steam in engineering thermodynamics. The actual implementation is as follows: a thermodynamic property calculation module based on the IAPWS-IF97 industrial standard formula published by the International Association for the Properties of Water and Steam is built into the digital electro-hydraulic control system (DEH) or distributed control system (DCS) of the turbine generator set. When the high-precision temperature and pressure sensors installed in front of the main steam valve and the exhaust port transmit the real-time collected working fluid temperature and pressure signals to the control system, the module immediately calls the corresponding regional function, such as the function for superheated steam region, to perform calculations, thereby quickly and accurately returning the specific enthalpy value at that measuring point.

[0129] In this embodiment, firstly, based on the current operating conditions of the turbine generator set, key operating parameters such as the temperature and pressure of the working fluid and the power target value set in the digital electro-hydraulic control system or coordinated control system are acquired through sensors. Then, based on the first law of thermodynamics and the principle of energy conservation, the calculation formula for the target working fluid flow rate is invoked. The unit efficiency is used to characterize the loss factors in the energy conversion process, while the specific enthalpy difference reflects the actual work capacity of a unit of working fluid in the turbine, thereby converting the abstract electrical power target into a specific working fluid flow rate requirement. Next, the calculated value serves as the core input parameter for subsequent iterative solutions to the target total valve position. This allows the control strategy to bypass the overshoot problem caused by the nonlinear characteristics of the valve in traditional PID control, establishing a precise correspondence between power demand and valve action at the essential level of flow rate. This provides a crucial quantitative basis for forming an effective valve position limit range and suppressing power oscillations.

[0130] In one embodiment, the iteration unit 202 is specifically used for:

[0131] First, assuming a master valve position and using it as the current master valve position, obtain the opening degree of each regulating valve according to the valve management curve;

[0132] It should be noted that after determining the target working fluid flow rate, in order to find the total valve position that precisely matches it, an initial total valve position value is first assumed and used as the input for the total valve position in the current iterative calculation, thus initiating the reverse solution process from valve position to flow rate. Then, based on the pre-tuned valve management curve and the established mapping relationship between the total valve position and the opening of each regulating valve, the system decomposes the assumed total valve position command into specific regulating valve opening values ​​by looking up tables or function interpolation. For example, if operating in sequential valve mode, different opening sequences of each valve are obtained; if operating in single valve mode, a uniform regulating valve opening is obtained. Next, this step concretizes the abstract total valve position, which represents the depth of the overall command, into a distribution of regulating valve openings that can directly act on the field actuators. It is not only the conversion hub connecting the upper-level flow demand and the lower-level valve action, but also provides accurate boundary conditions for subsequent calculation of the total working fluid flow rate by calling the valve flow characteristic function based on the opening of each regulating valve, ensuring that the iterative calculation can approach the target value along the actual valve configuration characteristics.

[0133] Then, using the valve flow characteristic function and the opening degree of each regulating valve, the working fluid flow of each regulating valve is calculated and the total working fluid flow is obtained by summing them up;

[0134] It should be noted that after obtaining the opening degree of each control valve, firstly, for each control valve in operation, its corresponding opening value is substituted as an independent variable into the valve flow characteristic function calibrated through experiments to calculate the working fluid mass flow rate through that single control valve. This function determines the nonlinear correspondence between valve opening degree and flow capacity. Then, the single-valve working fluid flow rates calculated for all control valves (e.g., partially open valves in sequential valve mode and synchronously operating valves in single valve mode) are algebraically summed to obtain the total working fluid flow rate of the turbine steam (or air) intake system under the current assumed total valve position. Next, this total working fluid flow rate serves as a key feedback quantity in the iterative loop, providing a direct comparison standard for subsequent difference comparison with the target working fluid flow rate. This determines the direction and magnitude of the subsequent bisection search, enabling the control algorithm to accurately backtrack to the actual total valve position command corresponding to the power requirement within the complex and nonlinear valve configuration characteristics. It can be understood that this step is the key step in mapping the physical action of the valve back to the flow effect.

[0135] Finally, the total working fluid flow rate is compared with the target working fluid flow rate. If the difference does not meet the convergence condition, the total valve position is updated using the bisection method and used as the current total valve position for total working fluid flow rate calculation until the convergence condition is met. Then, the corresponding total valve position is determined as the target total valve position.

[0136] It should be noted that after obtaining the total working fluid flow rate corresponding to the current assumed total valve position, it is first compared with the target working fluid flow rate calculated based on the power target in calculation unit 201. The difference between the two is calculated as an error criterion for measuring whether the current valve position command meets the load demand; then, if the absolute value of this difference ( The convergence accuracy threshold is greater than the preset threshold (e.g.) ( ), (The total valve position is the rated flow rate of the unit). This indicates that the currently assumed total valve position fails to match the actual flow capacity of the unit with the power command. At this point, the total valve position is updated using a bisection method. By dynamically adjusting the upper or lower boundary of the search interval and taking the median as the new total valve position, the mathematical property of the bisection method to quickly approximate the true value within the monotonic interval is utilized, which significantly reduces the number of iterations under nonlinear valve characteristics and avoids oscillations and divergences caused by parameter mutations. Then, the updated total valve position is used as the current value to return to the valve opening acquisition stage, and the closed-loop iterative process of flow accumulation and comparison is repeated until the difference between the total working fluid flow rate and the target working fluid flow rate meets the preset convergence condition. At this point, the corresponding total valve position is the optimal command value that can accurately compensate for the unit efficiency deviation and valve nonlinear mismatch under the current operating conditions. This is determined as the target total valve position, providing a unique and reliable central reference for setting the valve position limit interval, and avoiding power overshoot and oscillation problems caused by unreasonable DEH parameters or valve management curves.

[0137] In one embodiment, the step of calculating the working fluid flow rate of each regulating valve and accumulating the total working fluid flow rate using the valve flow characteristic function and the opening degree of each regulating valve in the iteration unit 202 includes:

[0138] First, when the valve management curve is a valve management curve under the sequential valve mode, the valves in the open state and their corresponding opening values ​​are obtained by looking up the table according to the current total valve position, so as to obtain the opening of each valve.

[0139] It should be noted that when the unit operates in sequential valve mode, the valve management curve uses the total valve position as the horizontal axis and the opening degree of each control valve as the vertical axis. The opening sequence and overlap of each control valve are defined by a preset piecewise function, so that the control valves operate sequentially rather than synchronously. Then, based on the current assumed or actual output total valve position command, the valve management curve data under this sequential valve mode is accessed by looking up a table. From this, the control valves in the open state and their corresponding specific opening values ​​are directly obtained, thereby resolving the single total valve position signal into a discrete opening distribution of each control valve. This lookup mapping process then enables the control logic to accurately identify the specific valve channel into which the working fluid flows and its respective throttling degree.

[0140] Then, when the valve management curve is a valve management curve under single valve mode, a unified valve opening value is obtained by looking up the table according to the current total valve position, and the opening of each valve is taken from the unified valve opening value to obtain the opening of each valve.

[0141] It should be noted that when the turbine generator set is operating in single-valve mode, the valve management curve sets the total valve position command and the opening degree of each regulating valve as a single linear or piecewise function mapping relationship. Then, in this mode, based on the current iteration assumption or the actual output total valve position value, the valve management curve data under this single-valve mode is accessed by looking up a table, and a unified regulating valve opening value is directly obtained from the table. This unified regulating valve opening value is then assigned to all regulating valves, meaning that the opening degree of each regulating valve takes the same value.

[0142] In one embodiment, the iteration unit 202 updates the total valve position using a binary search method, including:

[0143] Set initial upper and lower boundaries, and calculate the average value of the upper and lower boundaries; calculate the total working fluid flow rate based on the average value; if the total working fluid flow rate is greater than the target working fluid flow rate, then use the average value as the new upper boundary; otherwise, use the average value as the new lower boundary.

[0144] It should be noted that in the iterative solution of the target total valve position, an initial upper and lower boundary covering the possible range of the total valve position is first set, and the average value of the upper and lower boundaries is calculated. This average value is then used as the current total valve position and substituted into the subsequent flow calculation, thus providing an intermediate trial point for the search of nonlinear valve characteristics. Then, based on this current total valve position, the total working fluid flow rate is obtained by accumulating the valve management curve and the flow characteristic function of each regulating valve. This total working fluid flow rate is compared with the target working fluid flow rate: if the calculated total working fluid flow rate is greater than the target working fluid flow rate, then... If the current test valve position is too large, the average value is used as the new upper boundary to compress the high end of the search interval. Conversely, if the calculated total working fluid flow rate is less than or equal to the target working fluid flow rate, the test valve position is too small, and the average value is used as the new lower boundary to exclude the low end of the search interval. Then, the above median and boundary update operations are repeated, utilizing the inherent monotonically increasing relationship between the total valve position and the total working fluid flow rate to gradually shrink the search interval and quickly approach the true solution until the difference between the total working fluid flow rate and the target working fluid flow rate satisfies the preset convergence condition. This valve position update mechanism based on the bisection method effectively avoids the iterative divergence or slow convergence problems caused by the nonlinearity of the valve management curve, ensuring the efficiency and accuracy of the target total valve position calculation.

[0145] Note: Also known as the bisection search method or the binary search method, this is a classical numerical method for finding approximate roots of single-variable continuous function equations. Its basic principle is based on the Intermediate Value Theorem: for a function to be continuous and monotonic on the closed interval [a,b] (or at least have opposite signs at its two endpoints), the following formula is used: The function is used to divide the interval containing the root into two sub-intervals in each iteration, retaining the sub-interval where the function values ​​at the endpoints have opposite signs as the new search interval. By repeatedly performing the operations of "finding the midpoint, determining the sign, and shrinking the boundary," the range of the interval containing the root is gradually compressed until the interval length or function value is less than the preset tolerance. At this point, the midpoint of the interval can be used as an approximate solution to the equation. The significant characteristics of the bisection method are its simple algorithm structure, stable convergence behavior, and low requirement for the smoothness of the function. As long as the function is continuous within the interval and the two ends have opposite signs, it will definitely converge. Its convergence speed is linear, and each iteration can reduce the search interval by half. Therefore, in engineering calculations, it is often used for fast target value search in nonlinear mapping relationships that cannot be directly inverted or differentiated.

[0146] In one embodiment, the setting unit 203 is specifically used for:

[0147] The target total valve position is increased by a preset percentage as the upper limit value, and the target total valve position is decreased by the preset percentage as the lower limit value.

[0148] It should be noted that after accurately obtaining the target total valve position corresponding to the target working fluid flow rate through iterative calculation, the target total valve position is first used as the central reference value, and a preset percentage (e.g., ±5%) is added to it as the upper limit of the total valve position. At the same time, the target total valve position is reduced by the same preset percentage as the lower limit of the total valve position. Then, this combination of high and low thresholds forms a symmetrical and clear valve position limit range, which defines the boundary range for the valve action of the turbine generator set in real-time operation. Then, when power oscillation occurs, the valve opening change is monitored in real time. Once the valve opening attempts to exceed the valve position limit range due to unreasonable DEH parameters or valve management curve mismatch, the control logic will quickly limit the valve opening change and force it to operate within the high and low limits. This directly cuts off the abnormal disturbance of working fluid flow caused by valve overshoot or fluctuation, effectively suppressing the power oscillation amplitude from the mechanical execution level, and ensuring the stable operation of the unit near the target load and the safety of the power grid.

[0149] In summary, the power oscillation control system for a turbine generator set provided in this embodiment of the invention first calculates the target working fluid flow rate of the turbine generator set based on its operating parameters. By real-time acquisition of working fluid temperature, pressure, and target power values, and combining the thermodynamic enthalpy difference formula, the abstract electrical power demand is accurately converted into a specific working fluid flow rate demand, thus eliminating the nonlinear mismatch between power and valve opening from the fundamental source of energy conservation. Then, based on the pre-calibrated valve flow characteristic function and valve management curve, the target total valve position corresponding to the target working fluid flow rate is determined through iterative calculation. A bisection method is used to rapidly approximate the true value within the monotonic interval of the total valve position and the total working fluid flow rate, effectively compensating for distortions in the sequential valve overlap or single valve sections. The back-calculation error caused by flow nonlinearity ensures high accuracy and convergence efficiency of the target total valve position command. Next, with the target total valve position as the center, high and low limits are set to form a valve position limit range. A rigid boundary layer is constructed through preset percentage symmetrical limits, providing a safe physical constraint range for valve action from the command source. Finally, when power oscillations occur in the controlled turbine generator unit, the current total valve position is monitored in real time. If the current total valve position exceeds the valve position limit range, the change in the current total valve position is restricted, ensuring it operates within the valve position limit range. This restricts the valve opening change, directly cutting off abnormal disturbances in working fluid flow caused by valve overshoot or fluctuations, and suppressing power fluctuation amplitude within the allowable range. Therefore, this invention not only significantly reduces power oscillation amplitude and improves unit operation stability and grid security, but also reduces alternating mechanical stress on equipment by avoiding frequent large-amplitude valve movements, thereby extending unit life and reducing maintenance costs. This solves the problem that existing technologies cannot effectively suppress power oscillations caused by DEH parameters and valve management curve issues.

[0150] Example 5:

[0151] This invention also provides a control device for power oscillation of a turbine generator set, the device including a processor and a memory:

[0152] The memory is used to store program code and transmit the program code to the processor;

[0153] The processor is used to execute the steps of the turbine generator set power oscillation control method as described in the above method embodiments, according to the instructions in the program code.

[0154] It should be noted that this embodiment of the invention also provides a control device for power oscillation of a turbine generator set. This device can be directly deployed in a power plant's digital electro-hydraulic control system (DEH) or distributed control system (DCS) to execute the control method for suppressing power oscillation of the turbine generator set described in any of the foregoing embodiments. The control device specifically includes a processor and a memory. The memory stores program code implementing the above control method and transmits the program code to the processor during runtime. The processor then executes the following steps sequentially according to the instructions in the received program code: calculating the target working fluid flow rate based on the real-time operating parameters of the turbine generator set to be controlled; determining the target total valve position corresponding to the target working fluid flow rate through iterative calculation based on a pre-calibrated valve flow characteristic function and valve management curve; setting a valve position limit range centered on the target total valve position; and monitoring the valve opening in real time when power oscillation occurs. Once the valve opening is detected to exceed the valve position limit range, the valve opening change is immediately restricted to return to the limit range. This control device can transform all the technical features of the method of the present invention into online executable industrial control logic, effectively suppressing power oscillations caused by unreasonable DEH parameters or valve management curves, and improving the stability of unit operation and the security of the power grid.

[0155] Example 6:

[0156] This invention also provides a computer-readable storage medium for storing program code for executing the turbine generator set power oscillation control method described in the above method embodiments.

[0157] It should be noted that, in this embodiment of the invention, a computer-readable storage medium is also provided. This computer-readable storage medium stores program code, which, when loaded and executed by a processor, implements all or part of the steps of the control method for power oscillation of a turbine generator set as described in any of the above method embodiments. Specifically, the program code includes instructions for performing the following operations: calculating the target working fluid flow rate based on the operating parameters of the turbine generator set to be controlled; determining the target total valve position corresponding to the target working fluid flow rate through iterative calculation based on a pre-calibrated valve flow characteristic function and valve management curve; setting a high limit and a low limit value of the target total valve position centered on the target total valve position to form a valve position limit range; monitoring the valve opening in real time when power oscillation of the turbine generator set to be controlled occurs, and restricting the valve opening change when the valve opening exceeds the valve position limit range, so that it operates within the valve position limit range.

[0158] The computer-readable storage medium may include, but is not limited to, various physical carriers capable of storing program code long-term or temporarily, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. By deploying the program code in this storage medium to the control equipment of the power plant's existing digital electro-hydraulic control system or distributed control system, the power oscillation suppression method of this invention can be quickly ported to operating turbine generator sets without increasing additional hardware costs. This effectively suppresses power oscillations caused by unreasonable DEH parameters or valve management curves, improves unit operating stability and grid security, extends equipment lifespan, and reduces maintenance costs.

[0159] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0160] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0161] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0162] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0163] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0164] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling power oscillation in a turbine generator set, characterized in that, include: Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled. Based on the pre-calibrated valve flow characteristic function and valve management curve, the target total valve position corresponding to the target working fluid flow rate is determined through iterative calculation; Centered on the target main valve position, set the high limit and low limit of the target main valve position to form a valve position limit range; When the power oscillation of the turbine generator set to be controlled occurs, the current total valve position is monitored in real time. If the current total valve position exceeds the valve position limit range, the change of the current total valve position is restricted so that the current total valve position operates within the valve position limit range. In turn, the change of the valve opening is restricted by the mapping relationship between the total valve position and the valve opening in the valve management curve. The calculation of the target working fluid flow rate of the turbine generator set under control based on its operating parameters includes: Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled. The formula for calculating the target working fluid flow rate is as follows: ； In the formula, The target working fluid flow rate, This refers to the target power value in a digital electro-hydraulic control system or coordinated control system. To control the temperature of the turbine generator set, To control the pressure of the turbine generator set, To control the turbine efficiency of the turbine generator set, To control the generator efficiency of the turbine generator set, To determine the specific enthalpy of the working fluid at the inlet of the turbine generator set to be controlled. The specific enthalpy is the working fluid at the outlet of the turbine generator set to be controlled.

2. The method for controlling power oscillation of a turbine generator set according to claim 1, characterized in that, The step of determining the target total valve position corresponding to the target working fluid flow rate through iterative calculation based on a pre-calibrated valve flow characteristic function and valve management curve includes: S21. Assuming a master valve position and using it as the current master valve position, obtain the opening degree of each regulating valve according to the valve management curve; S22. Calculate the working fluid flow rate of each valve and sum them up to obtain the total working fluid flow rate using the valve flow characteristic function and the opening degree of each valve. S23. Compare the total working fluid flow rate with the target working fluid flow rate. If the difference does not meet the convergence condition, update the total valve position using the bisection method and return it to S21 as the current total valve position until the convergence condition is met. Then, determine the corresponding total valve position as the target total valve position.

3. The method for controlling power oscillation in a turbine generator set according to claim 2, characterized in that, The assumption is that a master valve position is used as the current master valve position. Based on the valve management curve, the opening degree of each regulating valve is obtained, including: When the valve management curve is a valve management curve under the sequential valve mode, the valves in the open state and their corresponding opening values ​​are obtained by looking up the table according to the current total valve position, so as to obtain the opening of each valve.

4. The method for controlling power oscillation of a turbine generator set according to claim 2, characterized in that, The assumption of a master valve position and using it as the current master valve position, along with obtaining the opening degree of each regulating valve based on the valve management curve, further includes: When the valve management curve is a valve management curve under single valve mode, a unified valve opening value is obtained by looking up the table according to the current total valve position, and the opening of each valve is taken from the unified valve opening value to obtain the opening of each valve.

5. The method for controlling power oscillation of a turbine generator set according to claim 2, characterized in that, The method of updating the master valve position using the binary search method includes: Set initial upper and lower boundaries, and calculate the average value of the upper and lower boundaries; The total working fluid flow rate is calculated based on the average value. If the total working fluid flow rate is greater than the target working fluid flow rate, the average value is used as the new upper boundary; otherwise, the average value is used as the new lower boundary.

6. The method for controlling power oscillation of a turbine generator set according to claim 1, characterized in that, The step of setting a high limit and a low limit for the target total valve position, centered on the target total valve position, to form a valve position limit range includes: The target total valve position is increased by a preset percentage as the upper limit value, and the target total valve position is decreased by the preset percentage as the lower limit value.

7. A control system for power oscillation in a turbine generator set, characterized in that, include: The calculation unit is used to calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled. The iterative unit is used to determine the target total valve position corresponding to the target working fluid flow rate by iterative calculation based on the pre-calibrated valve flow characteristic function and valve management curve. The setting unit is used to set the high limit and low limit of the target total valve position as the center, thereby forming a valve position limit range; The control unit is used to monitor the current total valve position in real time when the power oscillation of the turbine generator set to be controlled occurs. If the current total valve position exceeds the valve position limit range, the change of the current total valve position is restricted so that the current total valve position operates within the valve position limit range. In turn, the change of the valve opening is restricted by the mapping relationship between the total valve position and the valve opening in the valve management curve. The calculation of the target working fluid flow rate of the turbine generator set under control based on its operating parameters includes: Calculate the target working fluid flow rate of the turbine generator set to be controlled based on the operating parameters of the turbine generator set to be controlled. The formula for calculating the target working fluid flow rate is as follows: ； In the formula, The target working fluid flow rate, This refers to the target power value in a digital electro-hydraulic control system or coordinated control system. To control the temperature of the turbine generator set, To control the pressure of the turbine generator set, To control the turbine efficiency of the turbine generator set, To control the generator efficiency of the turbine generator set, To determine the specific enthalpy of the working fluid at the inlet of the turbine generator set to be controlled. The specific enthalpy is the working fluid at the outlet of the turbine generator set to be controlled.

8. A control device for power oscillation in a turbine generator set, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the power oscillation control method of the turbine generator set according to any one of the claims 1-6 according to the instructions in the program code.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the power oscillation control method for a turbine generator set according to any one of claims 1-6.

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