A quick load change control method for molten salt heat storage coupled combined heat and power system

Abstract

The application discloses a kind of fast variable load control methods of molten salt heat storage coupling combined heat and power system, the method first establishes the simplified dynamic model of combined heat and power unit and electric heater, then based on target variable load rate and combined heat and power unit dynamic model, calculates the feedforward compensation power of electric heater, and according to the deviation of system total output power and unit target power, feedback adjustment power is calculated by proportional-integral-derivative control algorithm, and feedforward compensation power and feedback adjustment power are synthesized as the final power instruction of electric heater.In addition, in the process of load tracking, control parameters and target variable load rate are adaptively adjusted according to the system operating state.The application can significantly improve the fast variable load capability of the system, realize accurate, fast and stable load tracking, and meet the demand of power grid for fast peak shaving and frequency modulation.

Description

Technical Field

[0001] This invention relates to the field of thermal power generation system operation and control technology, specifically to a rapid load change control method for a molten salt thermal storage coupled cogeneration system. Background Technology

[0002] Currently, the large-scale grid connection of renewable energy sources such as wind and solar power poses a severe challenge to the stable operation of the power grid due to the intermittent and highly volatile nature of their output. This necessitates that traditional thermal power units, especially combined heat and power (CHP) units, provide stronger flexibility in regulation to balance the power difference between the power source and the load in real time. Large CHP units, due to the significant thermal inertia of their main equipment such as boilers and turbines, exhibit significant lag and delay in responding to load commands, resulting in generally low load change rates. This makes it difficult to meet the grid's urgent needs for rapid peak shaving and frequency regulation. This sluggish regulation caused by the "heat-driven power generation" operating mode severely restricts the operational flexibility of the units.

[0003] Molten salt thermal energy storage technology, with its advantages of large storage capacity, low heat loss, high operating temperature, and long lifespan, is considered an effective technical path to improve the flexibility of thermal power units. By converting electrical energy or excess heat energy of the unit into sensible heat storage in high-temperature molten salt, and rapidly releasing heat when needed to replace part of the unit's steam extraction, "thermal-electric decoupling" can be achieved, thereby indirectly and quickly adjusting the unit's net electrical power output. However, the control strategies of molten salt thermal energy storage coupled cogeneration systems mostly adopt feedback control based on power deviation or simple rule control, which have the following limitations: 1) The response is lagging, and it cannot actively compensate for the unit's inertia in the early stages of load changes; 2) The control accuracy is limited, and it is easy to cause overshoot or oscillation; 3) It lacks the ability to adapt to different operating conditions and load change rate requirements. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a rapid load change control method for a molten salt thermal storage coupled cogeneration system that can actively and accurately offset inertial delay and has good adaptive capabilities.

[0005] Technical Solution: The present invention provides a rapid load change control method for a molten salt thermal storage coupled cogeneration system. The molten salt thermal storage coupled cogeneration system includes a cogeneration unit and a molten salt thermal storage subsystem. The molten salt thermal storage subsystem has an electric heater and a salt-water heat exchanger. The electric heater is used to start when a rapid load reduction is required, consuming electrical energy to heat and store the molten salt. The salt-water heat exchanger is used to heat the feedwater with high-temperature molten salt to generate steam when a rapid load increase is required, thereby reducing the amount of steam extracted by the unit.

[0006] The rapid load change control method includes:

[0007] S1: Dynamic modeling of molten salt thermal storage coupled cogeneration system: The power response characteristics of the cogeneration unit are characterized by a model consisting of a first-order inertial element and a pure delay element in series. The power response characteristics of the electric heater are characterized by a first-order inertial model. The total output power of the molten salt thermal storage coupled cogeneration system is defined as the sum of the actual power of the unit and the actual power of the electric heater.

[0008] S2: Based on the preset target load rate, dynamic power compensation combining feedforward and feedback is implemented for the electric heater, so that the total output power of the system can track the target power of the unit quickly and accurately at the desired rate; wherein, the feedback regulation adopts the proportional-integral-derivative control algorithm;

[0009] S3: During the execution of step S2, the operating status and control effect of the load tracking process are monitored online, and the target variable load rate and proportional-integral-derivative controller parameters are dynamically optimized based on the monitoring results. At the same time, safety constraints and abnormal protection are implemented for the real-time target power of the electric heater and the key status parameters of the molten salt thermal storage subsystem, so as to achieve fast, stable and safe load tracking under different operating conditions.

[0010] Furthermore, in step S1, the dynamic equation for the unit power is:

[0011]

[0012] in, for Actual power of the generator unit at any given time, in MW; The unit response time constant, in seconds; for Target power of generating units at any given time, in MW; Unit time delay, unit: seconds;

[0013] The dynamic equation for the power of the electric heater is:

[0014]

[0015] in, for Real-time electric heater power, unit: MW; The electric heater's response time constant, in seconds; for Target power of the electric heater at any given time, in MW;

[0016] Total output power of molten salt thermal storage coupled cogeneration system .

[0017] Further, step S2 includes:

[0018] S21: Based on the change in the unit's target power and the target load rate, calculate the theoretical adjustment time, and use the established series dynamic model of the first-order inertial link plus pure delay link of the cogeneration unit to predict the unit power at the end of the theoretical adjustment time under the condition that the unit's target power remains unchanged within the theoretical adjustment time, and then calculate the feedforward compensation power used to offset the unit's lag effect.

[0019] S22: Real-time acquisition of the total output power of the system, calculation of the real-time deviation between it and the target power of the unit, and the use of proportional-integral-derivative control algorithm to calculate the feedback adjustment power based on the real-time deviation in order to eliminate steady-state error and suppress overshoot;

[0020] S23: The feedforward compensation power and the feedback regulation power are superimposed to obtain the real-time target power of the electric heater. The real-time target power of the electric heater is sent as a command to the electric heater actuator to realize the rapid tracking of the total output power of the system to the target power of the unit.

[0021] Furthermore, in step S21, the formula for calculating the theoretical settling time is:

[0022]

[0023] in, Theoretical settling time, unit: min; The change in the target power of the generating unit, in MW; Target load rate, unit: MW / min;

[0024] The formula for calculating the predicted power of the generating unit is:

[0025]

[0026] in, The unit power is a predicted value, in MW;

[0027] The formula for calculating feedforward compensation power is:

[0028]

[0029] In the formula: The feedforward compensation power of the electric heater, in MW; The target power of the unit is expressed in MW.

[0030] Furthermore, in step S22, the formula for calculating the power deviation is:

[0031]

[0032] in, for Power deviation at any given time, in MW;

[0033] The formula for calculating feedback regulation power is:

[0034]

[0035] in, for Feedback-regulated power of the electric heater, unit: MW; , , The proportional, integral, and derivative coefficients of the proportional-integral-derivative controller are listed in order.

[0036] Further, step S3 includes:

[0037] S31: Real-time acquisition of operating data of molten salt thermal storage coupled cogeneration system, and calculation of the following performance indicators based on the operating data: actual load change rate, power overshoot, settling time and steady-state error;

[0038] S32: Based on the performance indicators obtained in step S31, and combined with the current unit operating conditions, online adjustments are made to the target variable load rate and / or the parameters of the proportional-integral-derivative controller using preset adjustment rules, fuzzy logic, or optimization algorithms.

[0039] S33: After obtaining the real-time target power of the electric heater in step S23, the amplitude and rate of change of the real-time target power of the electric heater are limited to meet the minimum power, maximum power and maximum ramp rate requirements of the electric heater; and the key status parameters of the molten salt thermal storage subsystem are monitored in real time; when an abnormal operating condition is detected, the protection logic is triggered.

[0040] Further, in step S31, the actual load change rate is the average slope of the total system output power over time within the adjustment range from the moment the load command changes until the total system output power first enters the allowable error band of the unit's target power. The power overshoot is the absolute value of the maximum excess of the total system output power relative to the unit's target power during the adjustment process. The adjustment time is the time from the moment the load command changes until the total system output power enters and remains within the allowable error band of the unit's target power. The steady-state error is the average value of the difference between the total system output power and the unit's target power within the preset steady-state judgment time window after the total system output power enters and remains within the allowable error band of the unit's target power.

[0041] Furthermore, in step S32, performance index thresholds, parameter adjustment rules, and parameter sets corresponding to different unit operating conditions are pre-stored; when the power overshoot exceeds the first preset threshold, the proportional coefficient is reduced and / or the derivative coefficient is increased to suppress overshoot; when the adjustment time exceeds the second preset threshold, the proportional coefficient is increased to enhance the dynamic response speed; when the steady-state error exceeds the third preset threshold for a consecutive preset number of control cycles, the integral coefficient is increased to reduce the steady-state deviation; when the molten salt thermal storage coupled cogeneration system is found to have frequent overshoot or adjustment oscillations in a consecutive number of control cycles, the effective target load change rate in the current control cycle is reduced, and then gradually restored to the original set value after the system stabilizes.

[0042] Furthermore, in step S32, the corresponding control parameter group is called according to the current unit load rate, main steam pressure or preset operating condition range, so that the same control method can be adapted to different load levels and different operating states.

[0043] Furthermore, in step S33, after the protection logic is triggered, at least one of the following protection actions is performed: blocking the electric heater power increase command, issuing an alarm signal, maintaining the current safe output, or switching to standby control mode / pure unit tracking mode.

[0044] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0045] This invention establishes a simplified dynamic model of the combined heat and power (CHP) unit and electric heater, employs a composite control method combining feedforward prediction and feedback regulation, and integrates operational status monitoring to achieve dynamic optimization of control parameters and safety protection. This invention can proactively compensate for unit inertial delays in the initial stage of load regulation and correct power deviations in real time during regulation, thereby improving the system's load tracking speed, tracking accuracy, and operational stability. Simultaneously, through online adjustment of control parameters and safety constraints and anomaly protection for power commands and critical system states, it further enhances the adaptability to different operating conditions and the safety and reliability of system operation. This invention has moderate computational complexity, making it easy to implement in existing distributed control systems or programmable logic controllers (PLCs), and possesses good engineering practical value. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the molten salt thermal storage coupled cogeneration system in an embodiment of the present invention;

[0047] Figure 2 This is a flowchart of a rapid load change control method for a molten salt thermal storage coupled cogeneration system provided in an embodiment of the present invention. Detailed Implementation

[0048] The invention will now be further described with reference to the accompanying drawings.

[0049] like Figure 1 The molten salt thermal storage coupled cogeneration system shown includes a cogeneration unit and a coupled molten salt thermal storage subsystem. The cogeneration unit includes a boiler, a steam turbine, and a generator. The molten salt thermal storage subsystem includes a high-temperature molten salt tank, a low-temperature molten salt tank, a molten salt pump, an electric heater, and a salt-water heat exchanger.

[0050] The basic working principle is as follows: when a rapid load reduction is required, the electric heater is activated to consume electrical energy to heat and store molten salt; when a rapid load increase is required, the high-temperature molten salt heats the feedwater through a salt-water heat exchanger to generate steam, reducing the amount of steam extracted by the unit and thus increasing the power generation capacity. The electric heater, as a rapid actuator, has its power dynamically adjusted by the rapid load change control method of this invention.

[0051] like Figure 2 As shown in the embodiment of the present invention, the rapid load change control method for a molten salt thermal storage coupled cogeneration system includes the following steps:

[0052] S1: Dynamic modeling of molten salt thermal storage coupled cogeneration system.

[0053] S11: Considering that the power output of a combined heat and power (CHP) unit is affected by the boiler's thermal inertia and heat storage characteristics, and exhibits dynamic response characteristics with inertial delay, a model consisting of a first-order inertial element and a pure delay element connected in series is used to characterize the power response characteristics of the CHP unit. The dynamic equation for the unit's power is shown in equation (1):

[0054] (1)

[0055] in, for Actual power of the generator unit at any given time, in MW; The unit response time constant, in seconds; for Target power of generating units at any given time, in MW; The time delay of the generator unit is expressed in seconds (s).

[0056] S12: As a fast-regulating unit, the electric heater has a much smaller response time constant than the combined heat and power unit. Its power response characteristics are characterized using a first-order inertial model. The dynamic equation for the electric heater's power is shown in equation (2):

[0057] (2)

[0058] in, for Real-time electric heater power, unit: MW; The electric heater's response time constant, in seconds; for Target power of electric heater at any time, unit: MW.

[0059] S13: Define the total output power of a molten salt thermal storage coupled cogeneration system (hereinafter referred to as the total system output power). Actual power of the unit With the actual power of the electric heater The sum is shown in equation (3):

[0060] (3)

[0061] S2: Based on the preset target load rate, dynamic power compensation combining feedforward and feedback is implemented on the electric heater, so that the total output power of the system can track the target power of the unit quickly and accurately at the desired rate; wherein, the feedback regulation adopts the proportional-integral-derivative control algorithm.

[0062] S21: Based on the change in the unit's target power and the target load rate, calculate the theoretical adjustment time, and use the series dynamic model of the cogeneration unit with a first-order inertial link plus a pure delay link established in step S11 to predict the unit's power at the end of the theoretical adjustment time, under the condition that the unit's target power remains unchanged within the theoretical adjustment time, and then calculate the feedforward compensation power used to offset the unit's lag effect.

[0063] The formula for calculating the theoretical settling time is shown in equation (4):

[0064] (4)

[0065] in, Theoretical settling time, unit: min; The change in the target power of the generating unit, in MW; Target variable load rate, unit: MW / min.

[0066] Based on the first-order inertial element plus pure delay element series model established in step S11, under the condition that the target power of the unit remains unchanged during the theoretical adjustment time, the dynamic equation of the unit power is solved to obtain the predicted value of the unit power at the end of the theoretical adjustment time. The calculation formula is shown in equation (5):

[0067] (5)

[0068] in, This is the predicted power output of the generating unit, in MW.

[0069] The formula for calculating the feedforward compensation power is shown in equation (6):

[0070] (6)

[0071] in, The feedforward compensation power of the electric heater, in MW; The target power of the unit is expressed in MW.

[0072] S22: Real-time acquisition of the system's total output power, calculation of the real-time deviation between it and the unit's target power, and the use of a proportional-integral-derivative control algorithm to calculate feedback adjustment power based on the real-time deviation in order to eliminate steady-state error and suppress overshoot.

[0073] The formula for calculating power deviation is shown in equation (7):

[0074] (7)

[0075] in, for Power deviation at any given time, in MW.

[0076] The formula for calculating the feedback regulation power is shown in equation (8):

[0077] (8)

[0078] in, for Feedback-regulated power of the electric heater, unit: MW; , , The proportional, integral, and derivative coefficients of the proportional-integral-derivative controller are listed in order.

[0079] S23: The feedforward compensation power and the feedback regulation power are superimposed to obtain the real-time target power of the electric heater. The real-time target power of the electric heater is sent as a command to the electric heater actuator to realize the rapid tracking of the total output power of the system to the target power of the unit.

[0080] Real-time target power of electric heater The calculation formula is shown in equation (9):

[0081] (9)

[0082] S3: During the execution of step S2, the operating status and control effect of the load tracking process are monitored online, and the target variable load rate and proportional-integral-derivative controller parameters are dynamically optimized based on the monitoring results. At the same time, safety constraints and abnormal protection are implemented for the real-time target power of the electric heater and the key status parameters of the molten salt thermal storage subsystem, so as to achieve fast, stable and safe load tracking under different operating conditions.

[0083] S31: Real-time acquisition of operating data such as the total output power, target power of the unit, actual power of the electric heater, and temperatures of the high-temperature molten salt tank, low-temperature molten salt tank, and liquid levels of the high-temperature and low-temperature molten salt tanks of the molten salt storage coupled cogeneration system, and recording of each load command change process; based on the operating data, calculate the following performance indicators: actual load change rate, power overshoot, adjustment time, and steady-state error; wherein, the actual load change rate is the average slope of the total output power of the system changing with time within the adjustment interval from the moment of load command change until the total output power of the system first enters the allowable error zone of the unit's target power; the power overshoot is the absolute value of the maximum excess of the total output power of the system relative to the unit's target power during the adjustment process; the adjustment time is the time from the moment of load command change until the total output power of the system enters and remains within the allowable error zone of the unit's target power; and the steady-state error is the average value of the difference between the total output power of the system and the unit's target power within a preset steady-state judgment time window after the total output power of the system enters and remains within the allowable error zone of the unit's target power.

[0084] S32: Based on the performance indicators obtained in step S31 and combined with the current unit operating conditions, the target load change rate and / or proportional-integral-derivative controller parameters are adjusted online. Specifically, performance indicator thresholds, parameter adjustment rules, and parameter sets corresponding to different unit operating conditions are pre-stored. When the power overshoot exceeds the first preset threshold, the proportional coefficient is reduced and / or the derivative coefficient is increased to suppress overshoot. When the adjustment time exceeds the second preset threshold, the proportional coefficient is increased to enhance the dynamic response speed. When the steady-state error exceeds the third preset threshold for a consecutive preset number of control cycles, the integral coefficient is increased to reduce the steady-state deviation. When the molten salt thermal storage coupled cogeneration system experiences frequent overshoot or adjustment oscillations in multiple consecutive control cycles, the effective target load change rate in the current control cycle is reduced, and then gradually restored to the original set value after the system stabilizes. In addition, the corresponding control parameter sets can be called according to the current unit load rate, main steam pressure, or preset operating condition range to adapt the same control method to different load levels and different operating states. The online adjustment can be implemented using preset adjustment rules, fuzzy logic, or optimization algorithms.

[0085] S33: After calculating the real-time target power of the electric heater in step S23, the amplitude and rate of change of the real-time target power of the electric heater are first limited to meet the minimum power, maximum power and maximum ramp rate requirements of the electric heater; then, key status parameters such as the temperature of the high-temperature molten salt tank, the temperature of the low-temperature molten salt tank, the liquid level of the high-temperature molten salt tank and the liquid level of the low-temperature molten salt tank are monitored in real time; when any of the following abnormal conditions are detected, the protection logic is triggered: the temperature of the high-temperature molten salt tank is lower than the preset safe heat release threshold, the temperature of the low-temperature molten salt tank is higher than the preset safe heat storage threshold, or the liquid level of the high-temperature molten salt tank and / or the liquid level of the low-temperature molten salt tank exceeds the preset safe range; after the protection logic is triggered, at least one of the following protection actions is executed: blocking the electric heater power increase command, issuing an alarm signal, maintaining the current safe output, or switching to standby control mode / pure unit tracking mode; through the above limiting and protection measures, the operation of the electric heater beyond the range and the molten salt heat storage subsystem continuing to perform high-risk regulation actions under abnormal conditions can be avoided, thereby ensuring the safety and reliability of the operation of the coupled molten salt heat storage cogeneration system.

[0086] In summary, this invention achieves modeling, compensation control, dynamic optimization, and safety protection for rapid load change processes in molten salt thermal storage coupled cogeneration systems. It can improve load response speed, tracking accuracy, and operational stability while ensuring the safe and reliable operation of the system, and has good engineering implementation effects.

Claims

1. A rapid load change control method for a molten salt thermal storage coupled cogeneration system, characterized in that, The molten salt thermal storage coupled cogeneration system includes a cogeneration unit and a molten salt thermal storage subsystem. The molten salt thermal storage subsystem has an electric heater and a salt-water heat exchanger. The electric heater is used to start when a rapid load reduction is required, consuming electrical energy to heat and store the molten salt. The salt-water heat exchanger is used to heat the feedwater with high-temperature molten salt to generate steam when a rapid load increase is required, thereby reducing the amount of steam extracted by the unit. The rapid load change control method includes: S1: Dynamic modeling of molten salt thermal storage coupled cogeneration system: The power response characteristics of the cogeneration unit are characterized by a model consisting of a first-order inertial element and a pure delay element in series. The power response characteristics of the electric heater are characterized by a first-order inertial model. The total output power of the molten salt thermal storage coupled cogeneration system is defined as the sum of the actual power of the unit and the actual power of the electric heater. S2: Based on the preset target load rate, dynamic power compensation combining feedforward and feedback is implemented for the electric heater, so that the total output power of the system can track the target power of the unit quickly and accurately at the desired rate; wherein, the feedback regulation adopts the proportional-integral-derivative control algorithm; S3: During the execution of step S2, the operating status and control effect of the load tracking process are monitored online, and the target variable load rate and proportional-integral-derivative controller parameters are dynamically optimized based on the monitoring results. At the same time, safety constraints and abnormal protection are implemented for the real-time target power of the electric heater and the key status parameters of the molten salt thermal storage subsystem, so as to achieve fast, stable and safe load tracking under different operating conditions.

2. The rapid load change control method according to claim 1, characterized in that, In step S1, the dynamic equation for the unit power is: in, for Actual power of the generator unit at any given time, in MW; The unit response time constant, in seconds; for Target power of generating units at any given time, in MW; Unit time delay, unit: seconds; The dynamic equation for the power of the electric heater is: in, for Real-time electric heater power, unit: MW; The electric heater's response time constant, in seconds; for Target power of the electric heater at any given time, in MW; Total output power of molten salt thermal storage coupled cogeneration system .

3. The rapid load change control method according to claim 2, characterized in that, Step S2 includes: S21: Based on the change in the unit's target power and the target load rate, calculate the theoretical adjustment time, and use the established series dynamic model of the first-order inertial link plus pure delay link of the cogeneration unit to predict the unit power at the end of the theoretical adjustment time under the condition that the unit's target power remains unchanged within the theoretical adjustment time, and then calculate the feedforward compensation power used to offset the unit's lag effect. S22: Real-time acquisition of the total output power of the system, calculation of the real-time deviation between it and the target power of the unit, and the use of proportional-integral-derivative control algorithm to calculate the feedback adjustment power based on the real-time deviation in order to eliminate steady-state error and suppress overshoot; S23: The feedforward compensation power and the feedback regulation power are superimposed to obtain the real-time target power of the electric heater. The real-time target power of the electric heater is sent as a command to the electric heater actuator to realize the rapid tracking of the total output power of the system to the target power of the unit.

4. The rapid load change control method according to claim 3, characterized in that, In step S21, the formula for calculating the theoretical settling time is: in, Theoretical settling time, unit: min; The change in the target power of the generating unit, in MW; Target load rate, unit: MW / min; The formula for calculating the predicted power of the generating unit is: in, The unit power is a predicted value, in MW; The formula for calculating feedforward compensation power is: In the formula: The feedforward compensation power of the electric heater, in MW; The target power of the unit is expressed in MW.

5. The rapid load change control method according to claim 4, characterized in that, In step S22, the formula for calculating the power deviation is: in, for Power deviation at any given time, in MW; The formula for calculating feedback regulation power is: in, for Feedback-regulated power of the electric heater, unit: MW; , , The proportional, integral, and derivative coefficients of the proportional-integral-derivative controller are listed in order.

6. The rapid load change control method according to any one of claims 3 to 5, characterized in that, Step S3 includes: S31: Real-time acquisition of operating data of molten salt thermal storage coupled cogeneration system, and calculation of the following performance indicators based on the operating data: actual load change rate, power overshoot, settling time and steady-state error; S32: Based on the performance indicators obtained in step S31, and combined with the current unit operating conditions, online adjustments are made to the target variable load rate and / or the parameters of the proportional-integral-derivative controller using preset adjustment rules, fuzzy logic, or optimization algorithms. S33: After obtaining the real-time target power of the electric heater in step S23, the amplitude and rate of change of the real-time target power of the electric heater are limited to meet the minimum power, maximum power and maximum ramp rate requirements of the electric heater; and the key status parameters of the molten salt thermal storage subsystem are monitored in real time; when an abnormal operating condition is detected, the protection logic is triggered.

7. The rapid load change control method according to claim 6, characterized in that, In step S31, the actual load change rate is the average slope of the total system output power over time within the adjustment range from the moment the load command changes until the total system output power first enters the allowable error band of the unit's target power. The power overshoot is the absolute value of the maximum excess of the total system output power relative to the unit's target power during the adjustment process. The adjustment time is the time from the moment the load command changes until the total system output power enters and remains within the allowable error band of the unit's target power. The steady-state error is the average value of the difference between the total system output power and the unit's target power within the preset steady-state judgment time window after the total system output power enters and remains within the allowable error band of the unit's target power.

8. The rapid load change control method according to claim 6, characterized in that, In step S32, performance index thresholds, parameter adjustment rules, and parameter sets corresponding to different unit operating conditions are pre-stored. When the power overshoot exceeds the first preset threshold, the proportional coefficient is reduced and / or the derivative coefficient is increased to suppress overshoot. When the adjustment time exceeds the second preset threshold, the proportional coefficient is increased to enhance the dynamic response speed. When the steady-state error exceeds the third preset threshold for a consecutive preset number of control cycles, the integral coefficient is increased to reduce the steady-state deviation. When the molten salt thermal storage coupled cogeneration system is found to have frequent overshoot or adjustment oscillations in multiple consecutive control cycles, the effective target load change rate in the current control cycle is reduced, and then gradually restored to the original set value after the system stabilizes.

9. The rapid load change control method according to claim 8, characterized in that, In step S32, the corresponding control parameter group is also called according to the current unit load rate, main steam pressure or preset operating condition range, so that the same control method can be adapted to different load levels and different operating states.

10. The rapid load change control method according to claim 6, characterized in that, In step S33, after the protection logic is triggered, at least one of the following protection actions is performed: blocking the electric heater power increase command, issuing an alarm signal, maintaining the current safe output, or switching to standby control mode / pure unit tracking mode.

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