Intelligently regulated parameter water turbine governing system and method

Abstract

The application discloses a kind of intelligent parameter regulating water turbine governing system and method, and the governing system includes governor PLC control system and unit simulation PLC system;During the process of adjusting parameter, governor PLC control system sends water head and opening degree given signal to unit simulation PLC system, and unit simulation PLC system feeds back unit frequency, opening degree and active power signal to governor PLC control system;When receiving parameter adjustment instruction or water head changes more than set value, governor PLC control system extracts current condition opening degree and power step response signal from simulation system, and adjusts PID parameter of governing system based on Lambda setting method by analyzing signal key index.The method can intelligently and accurately adjust PID parameter of governing system under different water heads, improve the intelligence and accuracy of governing system adjustment, and provide guarantee for safe and stable operation of power system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water turbine speed regulation simulation, and relates to a water turbine speed regulation system and method with intelligent regulation parameters. BACKGROUND

[0002] In a power system, a large amount of peak regulation and frequency regulation tasks are undertaken by a hydroelectric generating set. The hydroelectric generating set should adjust the guide vane opening degree or output power of the hydroelectric generating set in a timely and rapid manner according to the dispatching requirements of a power grid and the frequency variation of the power grid, so as to meet the needs of active power balance and frequency regulation of the power grid. For a grid-connected hydroelectric generating set, in order to meet the regulation needs of the power grid, an opening degree regulation mode or a power regulation mode is generally adopted for regulation. The traditional opening degree regulation mode or power regulation mode is a feedback control mode, which generates a water turbine servomotor control output according to a certain power law by using the difference between a target opening degree or power and an actual value. The traditional regulation mode has a relatively high requirement for the setting of regulation parameters. When the control parameters are too large, oscillation and over-regulation are prone to occur. When the control parameters are too small, the regulation speed often cannot meet the requirements. In addition, due to the nonlinear influence of the characteristics of the water turbine, especially when the operating water head of the unit changes, a set of parameters often cannot meet the accurate control of the unit, and needs to be corrected.

[0003] At present, most water turbine generators adopt PID control parameters set based on one or several special working conditions to realize control. When setting the parameters, an external simulation tester or a traversal method needs to be adopted, and on this basis, the control parameters are simply switched according to real-time operating condition parameters, so as to improve the regulation ability of the unit under different operating conditions. However, due to the limitation of the parameter setting method of the speed regulator, the overall regulation performance of the unit under different water heads is often difficult to guarantee. When the unit participates in the peak regulation and frequency regulation task, there is inevitably a conflict problem between the efficient utilization of water energy operating condition and the high-quality peak regulation and frequency regulation condition on the dispatching side.

[0004] The current unit often adopts PID control parameters set in special working conditions. Under a specific operating water head, the set PID parameters may cause a decline in regulation performance.

[0005] When setting the PID control parameters, an external simulation tester is needed, which is inconvenient for actual operation.

[0006] The setting of the parameters often uses a trial-and-error method, and lacks a fixed setting algorithm. SUMMARY

[0007] The technical problem to be solved by the application is to provide a water turbine speed regulation system and method with intelligent regulation parameters, to improve the reliability of the speed measurement channel of the hydroelectric generating set, to ensure that the comprehensive speed value of the speed regulator is reasonable and effective, to avoid fluctuations in the speed of the unit, and to improve the stability of the operation of the hydroelectric generating set.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is: a water turbine speed regulation system with intelligent regulation parameters, the speed regulation system comprising a speed regulator PLC control system and a unit simulation PLC system; in the process of regulating parameters, the speed regulator PLC control system sends water head and opening degree given signals to the unit simulation PLC system, and the unit simulation PLC system feeds back unit frequency, opening degree and active power signals to the speed regulator PLC control system.

[0009] The unit simulation PLC system comprises a hydraulic amplification link, a hydraulic actuator, a main servomotor, a guide vane system, a water turbine, a generator and a power grid.

[0010] The unit simulation PLC system building method comprises the following steps:

[0011] SA1, a simulation model is built in simulation software; the hydraulic amplification link is a proportional link, the hydraulic actuator and the main servomotor are first-order inertia links, the guide vane system is a main servomotor stroke-guide vane opening degree curve table, the water turbine is a water head-opening degree-mechanical power curve table, the generator is a second-order synchronous motor model, and the power grid is an infinite power grid model;

[0012] SA2, the simulation model and the solver are converted into C language codes through a code conversion module in the simulation software;

[0013] SA3, an input and output conversion interface is designed in a PLC integrated development environment (IDE), and the simulation model code and the input and output interface code are uploaded into the PLC together.

[0014] The PID automatic regulation method of the water turbine speed regulation system with intelligent regulation parameters as described above comprises the following steps:

[0015] SB1, the speed regulator PLC control system outputs a current water head value and a guide vane given step signal to the unit simulation PLC system, and the guide vane given value is stepped from a no-load opening degree to 90% of the opening degree;

[0016] SB2, the unit simulation PLC system calculates a guide vane opening degree curve Y(t) and an active power curve P(t) in the regulation process and feeds back to the speed regulator PLC control system;

[0017] SB3, the key characteristic quantities of the curves in the discrete system are analyzed, and the opening degree mode and the power mode PID parameter setting methods are consistent;

[0018] SB4, based on the above step response characteristic quantities, according to the lambda setting method and the ZN setting method, the ideal type PID parameters are respectively:

[0019]

[0020] In the formula, ;

[0021] SB5 converts ideal PID parameters into discrete parallel PID parameters for engineering applications:

[0022] The relationship between PID and ideal PID is as follows:

[0023]

[0024]

[0025] Converting parallel PID controllers to discrete form yields:

[0026]

[0027] Therefore, the calculation method for the parameters of a discrete parallel PID controller is as follows:

[0028]

[0029] Substituting the formula from step four, we get:

[0030]

[0031] This is the final set value for the PID controller of the final speed governor system.

[0032] In SB3, the specific feature quantities and their judgment criteria include the following steps:

[0033] SB3-1, by judging the conditions Determine the inflection point of the adjustment curve. M(k1,Y[k1]) ;

[0034] SB3-2, draw the tangent line at this point, the slope of which is . (Y[k1]-Y[k1-1]) The intersection of the tangent and the unloaded opening is N((Y [K1]-Y0) / (Y[k1]-Y[k1-1]),Y0) In the formula, Y0 is the unloaded opening degree;

[0035] SB3-3, Adjusting system delay Adjusting the system time coefficient Adjustment coefficient ;

[0036] In the formula, △%OP is the per-unit value of the given quantity deviation, △%PV is the per-unit value of the response quantity deviation; Y0 is the initial value of the response, Y SS Both are per-unit values ​​in response to stable values.

[0037] The parameter adjustment judgment logic of the intelligent parameter adjustment hydro turbine speed control system described above includes the following steps:

[0038] SC1 determines whether the head value differs from the head value of the last PID parameter tuning by 10m, or whether there is a parameter tuning instruction. If there is, the parameter tuning process is entered; otherwise, the PID parameters remain unchanged.

[0039] SC2, the setting process begins. The governor control system outputs the current head value and guide vane setpoint step signal to the unit simulation system. The guide vane setpoint jumps from the no-load opening to 90% opening.

[0040] SC3 calculates the step response of the guide vane opening and the active power of the unit by the unit simulation system and feeds it back to the governor control system.

[0041] SC4 analyzes the key characteristic quantities of the curve in the discrete system and calculates the PID tuning value of the governor control system. The corresponding values ​​are assigned to the PID parameters of the power mode and the PID parameters of the opening mode, and the current head and PID parameters are recorded.

[0042] The main beneficial effects of this invention are as follows:

[0043] When a parameter adjustment command is received or the head change exceeds the set value, the speed governor PLC control system extracts the step response signals of the opening degree and power from the simulation system under the current conditions. By analyzing the key indicators of the signals, the PID parameters of the speed governor system are tuned based on the Lambda tuning method. This method can intelligently and accurately adjust the PID parameters of the speed governor system under different heads, improving the intelligence and accuracy of the speed governor system's regulation and providing a guarantee for the safe and stable operation of the power system. Attached Figure Description

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0045] Figure 1 This is a diagram of the speed controller PLC control system of the present invention.

[0046] Figure 2 This is a block diagram of the unit simulation system model of the present invention.

[0047] Figure 3 This is a flowchart illustrating the construction of the PLC-based unit simulation system of the present invention.

[0048] Figure 4 This is a schematic diagram of the step response feature extraction of the present invention.

[0049] Figure 5 This is a logic diagram of intelligent adjustment of parameters for the turbine speed control system of the present invention. Detailed Implementation

[0050] like Figures 1-5In this paper, a water turbine speed regulation system with intelligent parameter adjustment is disclosed. The speed regulation system includes a governor PLC control system and a unit simulation PLC system. During the parameter adjustment process, the governor PLC control system sends the head and opening degree given signals to the unit simulation PLC system, and the unit simulation PLC system feeds back the unit frequency, opening degree, and active power signals to the governor PLC control system.

[0051] The components of the unit simulation PLC system include the hydraulic amplification stage, hydraulic actuator, main servo motor, guide vane system, turbine, generator, and power grid.

[0052] Preferably, when a parameter adjustment command is received or the head change exceeds the set value, the speed governor PLC control system extracts the step response signals of the opening degree and power from the simulation system under the current conditions, and tunes the PID parameters of the speed governor system based on the Lambda tuning method by analyzing the key indicators of the signals.

[0053] In the preferred embodiment, the method for building the unit simulation PLC system includes the following steps:

[0054] SA1, build a simulation model in simulation software; the hydraulic amplification link is a proportional link, the hydraulic actuator and the main servo are both first-order inertial links, the guide vane system is the main servo stroke-guide vane opening curve table, the turbine is the head-opening-mechanical power curve table, the generator is a second-order synchronous motor model, and the power grid is an infinite power grid model.

[0055] SA2 converts the simulation model and solver into C language code through the code conversion module in the simulation software.

[0056] SA3 designs the input / output conversion interface in the PLC integrated development environment (IDE) and uploads the simulation model code and input / output interface code to the PLC.

[0057] In the preferred embodiment, the PID automatic control method for the turbine speed control system with intelligent adjustment parameters as described above includes the following steps:

[0058] SB1, the speed governor PLC control system outputs the current head value and guide vane setpoint step signal to the unit simulation PLC system, and the guide vane setpoint jumps from the no-load opening to 90% opening;

[0059] SB2, the unit simulation PLC system calculates the guide vane opening curve Y(t) and active power curve P(t) during the adjustment process, and feeds them back to the speed governor PLC control system;

[0060] SB3 analyzes the key characteristic quantities of curves in discrete systems, and the PID parameter tuning methods for the opening mode and power mode are consistent.

[0061] SB4, based on the above step response characteristics, and according to the lambda tuning method and the ZN tuning method, the ideal PID parameters are as follows:

[0062]

[0063] In the formula ;

[0064] SB5 converts ideal PID parameters into discrete parallel PID parameters for engineering applications:

[0065] The relationship between PID and ideal PID is as follows:

[0066]

[0067]

[0068] Converting parallel PID controllers to discrete form yields:

[0069]

[0070] Therefore, the calculation method for the parameters of a discrete parallel PID controller is as follows:

[0071]

[0072] Substituting the formula from step four, we get:

[0073]

[0074] This is the final set value for the PID controller of the final speed governor system.

[0075] In the preferred embodiment, SB3 includes the following steps regarding the specific feature quantities and their judgment criteria:

[0076] SB3-1, by judging the conditions Determine the inflection point of the adjustment curve. M(k1,Y[k1]) ;

[0077] SB3-2, draw the tangent line at this point, the slope of which is . (Y[k1]-Y[k1-1]) The intersection of the tangent and the unloaded opening is N((Y [K1]-Y0) / (Y[k1]-Y[k1-1]),Y0) In the formula, Y0 is the unloaded opening degree;

[0078] SB3-3, Adjusting system delay Adjusting the system time coefficient Adjustment coefficient ;

[0079] In the formula, △%OP is the per-unit value of the given quantity deviation, △%PV is the per-unit value of the response quantity deviation; Y0 is the initial value of the response, Y SSBoth are per-unit values ​​in response to stable values.

[0080] In the preferred embodiment, the parameter adjustment judgment logic of the intelligent parameter adjustment hydro turbine speed control system described above includes the following steps:

[0081] SC1 determines whether the head value differs from the head value of the last PID parameter tuning by 10m, or whether there is a parameter tuning instruction. If there is, the parameter tuning process is entered; otherwise, the PID parameters remain unchanged.

[0082] SC2, the setting process begins. The governor control system outputs the current head value and guide vane setpoint step signal to the unit simulation system. The guide vane setpoint jumps from the no-load opening to 90% opening.

[0083] SC3 calculates the step response of the guide vane opening and the active power of the unit by the unit simulation system and feeds it back to the governor control system.

[0084] SC4 analyzes the key characteristic quantities of the curve in the discrete system and calculates the PID tuning value of the governor control system. The corresponding values ​​are assigned to the PID parameters of the power mode and the PID parameters of the opening mode, and the current head and PID parameters are recorded.

[0085] The above method intelligently and accurately adjusts the PID parameters of the speed governor PLC control system under different water heads, improving the intelligence and accuracy of the speed governor PLC control system and providing a guarantee for the safe and stable operation of the power system.

[0086] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A smart turbine speed control system with adjustable parameters, characterized in that: The speed control system includes a speed controller PLC control system and a unit simulation PLC system; During the parameter adjustment process, the governor PLC control system sends the head and opening degree given signals to the unit simulation PLC system, and the unit simulation PLC system feeds back the unit frequency, opening degree, and active power signals to the governor PLC control system. The components of the unit simulation PLC system include the hydraulic amplification stage, hydraulic actuator, main servo drive, guide vane system, turbine, generator, and power grid. The method for building a unit simulation PLC system includes the following steps: SA1, build a simulation model in simulation software; the hydraulic amplification link is a proportional link, the hydraulic actuator and the main servo are both first-order inertial links, the guide vane system is the main servo stroke-guide vane opening curve table, the turbine is the head-opening-mechanical power curve table, the generator is a second-order synchronous motor model, and the power grid is an infinite power grid model. SA2 converts the simulation model and solver into C language code through the code conversion module in the simulation software. SA3 designs the input / output conversion interface in the PLC integrated development environment (IDE) and uploads the simulation model code and input / output interface code to the PLC.

2. The PID automatic control method for a turbine speed control system with intelligent parameter adjustment according to claim 1, characterized in that, Includes the following steps: SB1, the speed governor PLC control system outputs the current head value and guide vane setpoint step signal to the unit simulation PLC system, and the guide vane setpoint jumps from the no-load opening to 90% opening; SB2, the unit simulation PLC system calculates the guide vane opening curve Y(t) and active power curve P(t) during the adjustment process, and feeds them back to the speed governor PLC control system; SB3 analyzes the key characteristic quantities of curves in discrete systems, and the PID parameter tuning methods for the opening mode and power mode are consistent. SB4, based on the above step response characteristics, and according to the lambda tuning method and the ZN tuning method, the ideal PID parameters are as follows: In the formula ; SB5 converts ideal PID parameters into discrete parallel PID parameters for engineering applications: The relationship between PID and ideal PID is as follows: Converting parallel PID controllers to discrete form yields: Therefore, the calculation method for the parameters of a discrete parallel PID controller is as follows: Substituting the formula from step four, we get: This is the final set value for the PID controller of the final speed governor system.

3. The PID automatic control method for a turbine speed control system with intelligent parameter adjustment according to claim 2, characterized in that, In SB3, the specific feature quantities and their judgment criteria include the following steps: SB3-1, by judging the conditions Determine the inflection point of the adjustment curve. M (k1,Y[k1]) ; SB3-2, draw the tangent line at this point, the slope of which is . (Y[k1]-Y[k1-1]) The intersection of the tangent and the unloaded opening is N((Y [K1]-Y0) / (Y[k1]-Y[k1-1]),Y0) In the formula, Y0 is the unloaded opening degree; SB3-3, Adjusting system delay Adjusting the system time coefficient Adjustment coefficient ; In the formula, △%OP is the per-unit value of the given quantity deviation, △%PV is the per-unit value of the response quantity deviation; Y0 is the initial value of the response, Y SS Both are per-unit values ​​in response to stable values.

4. The parameter adjustment judgment logic of the intelligent parameter adjustment hydro-turbine speed control system according to claim 1, characterized in that, Includes the following steps: SC1 determines whether the head value differs from the head value of the last PID parameter tuning by 10m, or whether there is a parameter tuning instruction. If there is, the parameter tuning process is entered; otherwise, the PID parameters remain unchanged. SC2, the setting process begins. The governor control system outputs the current head value and guide vane setpoint step signal to the unit simulation system. The guide vane setpoint jumps from the no-load opening to 90% opening. SC3 calculates the step response of the guide vane opening and the active power of the unit by the unit simulation system and feeds it back to the governor control system. SC4 analyzes the key characteristic quantities of the curve in the discrete system and calculates the PID tuning value of the governor control system. The corresponding values ​​are assigned to the PID parameters of the power mode and the PID parameters of the opening mode, and the current head and PID parameters are recorded.

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