Control Method and System for Power Closed-Loop and Primary Frequency Regulation of Hydropower Station Generators

Abstract

The present invention discloses a control method and system for power closed-loop and primary frequency regulation of a hydropower station generator, which relates to the field of water conservancy and hydropower. The method includes: S1 collecting the actual active power and the primary frequency regulation action signal; S2 judging whether primary frequency regulation acts. If it acts, proceed to S3; if not, proceed to S4. S3 judges whether the set command is valid. If it is valid, proceed to S5; if not, return to S2. S4 judges whether the set command is valid. If it is valid, proceed to S5; if not, proceed to S6. S5 judges the relationship between the target value, the actual value and the control dead zone, and controls the guide vane actuator to act. S6 judges the relationship between the set value, the actual value and the control dead zone, and controls the guide vane actuator to act. The system includes a collection module, a governor for adjusting the guide vane opening, a PLC controller and a unit LCU. Through the method of the present invention, the purpose of superimposing and simultaneously adjusting the power closed-loop and the primary frequency regulation action of the governor in the opening mode is realized, and the accuracy of the power control of the hydropower station generator and the anti-interference ability of the power grid are improved.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy and hydropower, and particularly to a control method and system for power closed-loop and primary frequency modulation of a hydropower station generator. Background Art

[0002] With the construction of large-scale hydropower stations, the proportion of hydro-generating units in the power grid is also increasing continuously. The problem that hydro-generating units affect the frequency stability of the power system has gradually emerged. The quality of regulation and the reliability of operation of hydro-generating units directly affect the safe and reliable operation of hydro-generating sets and even the power system and the power quality. Since the governor of a hydropower station operates relatively stably in the opening mode, which helps to extend the service life of the actuator, the governor of a hydropower station generally chooses to operate in the opening mode. However, the opening mode of the governor performs closed-loop regulation with the given value of the turbine guide vane opening as the target value. For units with large head changes, the active power fluctuates significantly in the opening mode, and during the primary frequency modulation action, the closed-loop regulation of the active power cannot be achieved, which is not conducive to the stability of the power grid. Summary of the Invention

[0003] The purpose of the present invention is to design a control method and system for power closed-loop and primary frequency modulation of a hydropower station generator to solve the above problems.

[0004] The present invention realizes the above purpose through the following technical solutions:

[0005] A control method for power closed-loop and primary frequency modulation of a hydropower station generator includes the following steps:

[0006] S1. Collect the actual active power of the unit and the primary frequency modulation action signal of the governor;

[0007] S2. Judge whether the primary frequency modulation acts; if it acts, enter S3; if it does not act, enter S4;

[0008] S3. Judge whether the active power setting command of the unit LCU is valid. If it is valid, make the active power regulation target value of the unit LCU equal to the current active power setting increment of the unit LCU + the actual value of the active power when the active power setting command of the unit LCU is valid, and enter S5. If it is not valid, the governor determines the action amount of the guide vane opening according to the current primary frequency modulation action frequency difference and returns to S2;

[0009] S4. Judge whether the active power setting command of the unit LCU is valid. If it is valid, make the active power regulation target value of the unit LCU equal to the current active power setting value of the unit LCU and enter S5. If it is not valid, enter S6;

[0010] S5. Judge the relationship between the active power regulation target value of the unit LCU, the current actual active power value of the unit, and the control dead zone, send relevant control commands to the governor, and the governor controls the guide vane actuator to perform corresponding opening and closing actions until the active power regulation target value of the unit LCU and the current actual active power value of the unit are within the control dead zone, then reset the active power setting command. If entering S5 from S3, return to S3; if entering S5 from S4, return to S4;

[0011] S6. Judge the relationship between the current active power setting value of the unit LCU, the current actual active power value of the unit, and the control dead zone, send relevant control commands to the governor, and the governor controls the guide vane actuator to perform corresponding opening and closing actions until the current active power setting value of the unit LCU and the current actual active power value of the unit are within the control dead zone.

[0012] A control system for power closed-loop and primary frequency modulation of a hydropower station generator, comprising:

[0013] An acquisition module; the acquisition module is used to acquire the actual active power of the unit and the primary frequency modulation action signal of the governor;

[0014] A governor for adjusting the guide vane opening; the control signal output end of the governor is connected to the control signal input end of the guide vane actuator;

[0015] A PLC controller; the PLC controller is used to calculate the guide vane opening action amount according to the primary frequency modulation action frequency difference and control the working state of the governor, and the control signal output end of the PLC controller is connected to the control signal input end of the governor;

[0016] A unit LCU; the unit LCU is used to judge the working state of the whole unit and output control commands to the PLC controller according to the working state. The data signal input end of the unit LCU is connected to the data signal output end of the acquisition module, and the control signal output end of the unit LCU is connected to the control signal input end of the PLC controller.

[0017] The beneficial effects of the present invention are as follows: Through the control method of the present invention, the purpose of superimposing and simultaneously adjusting the power closed-loop and the primary frequency modulation action of the governor in the opening mode is achieved, improving the accuracy of the hydropower station generator power control and the anti-interference ability of the power grid, and being beneficial to the stability and reliability of the power grid. Description of the Drawings

[0018] Figure 1 It is a schematic flow chart of the control method for power closed-loop and primary frequency modulation of the hydropower station generator of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the control system for power closed-loop and primary frequency modulation of the hydropower station generator of the present invention. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships in which the inventive product is usually placed during use, or the orientation or positional relationships commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0024] In addition, the terms "first", "" etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, terms such as "set", "connect" should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings.

[0027] As Figure 1As shown, a control method for the power closed-loop and primary frequency regulation of a hydropower station generator includes the following steps:

[0028] S1. Collect the actual active power of the unit and the primary frequency regulation action signal of the governor.

[0029] S2. Determine whether primary frequency regulation is in action; if primary frequency regulation is in action, go to S3; if primary frequency regulation is not in action, go to S4.

[0030] S3. Determine whether the active power setting command of the unit LCU is valid. If it is valid, set the active power regulation target value of the unit LCU to be equal to the current active power setting increment of the unit LCU plus the actual active power value when the active power setting command of the unit LCU is valid, and go to S5. If it is not valid, the governor determines the guide vane opening action amount according to the current primary frequency regulation action frequency difference and returns to S2.

[0031] S4. Determine whether the active power setting command of the unit LCU is valid. If it is valid, set the active power regulation target value of the unit LCU to be equal to the current active power setting value of the unit LCU and go to S5. If it is not valid, go to S6.

[0032] S5. Determine the relationship between the active power regulation target value of the unit LCU, the current actual active power value of the unit, and the control dead zone, send relevant control commands to the governor, and the governor controls the guide vane actuator to perform corresponding opening and closing actions until the active power regulation target value of the unit LCU and the current actual active power value of the unit are within the control dead zone, and then reset the active power setting command. If entering S5 from S3, return to S3; if entering S5 from S4, return to S4. The specific steps are as follows:

[0033] S51. Determine whether the difference between the active power regulation target value of the unit LCU and the current actual active power value of the unit is greater than the maximum value of the control dead zone;

[0034] S52. If so, send a command to open the guide vane to the governor and return to S51; if not, go to S53;

[0035] S53. Determine whether the difference between the active power regulation target value of the unit LCU and the current actual active power value of the unit is less than the minimum value of the control dead zone;

[0036] S54. If so, send a command to close the guide vane to the governor and return to S53; if not, go to S55;

[0037] S55. If entering S5 from S3, return to S3; if entering S5 from S4, return to S4.

[0038] S6. Determine the relationship between the current unit LCU active power set value, the current unit actual active power value, and the control dead zone, and send relevant control commands to the governor. The governor controls the guide vane actuator to perform corresponding opening and closing actions until the current unit LCU active power set value and the current unit actual active power value are within the control dead zone. The specific steps are as follows:

[0039] S61. Determine whether the difference between the current unit LCU active power set value and the current unit actual active power value is greater than the maximum value of the control dead zone;

[0040] S62. If so, send an open guide vane command to the governor and return to S61; if not, proceed to S63;

[0041] S63. Determine whether the difference between the current unit LCU active power set value and the current unit actual active power value is less than the minimum value of the control dead zone;

[0042] S64. If so, send a close guide vane command to the governor and return to S63; if not, end.

[0043] Through the control method of the present invention, the purpose of the governor to superimpose and adjust the power closed-loop and primary frequency modulation actions simultaneously in the opening mode is achieved, improving the accuracy of the power control of the hydropower station generator and the anti-interference ability of the power grid, and being beneficial to the stability and reliability of the power grid.

[0044] As Figure 2 shown, a control system for the power closed-loop and primary frequency modulation of a hydropower station generator includes:

[0045] An acquisition module; the acquisition module is used to acquire the actual active power of the unit and the primary frequency modulation action signal of the governor;

[0046] A governor for adjusting the guide vane opening; the control signal output end of the governor is connected to the control signal input end of the guide vane actuator;

[0047] A PLC controller; the PLC controller is used to control the working state of the governor, and the control signal output end of the PLC controller is connected to the control signal input end of the governor;

[0048] A unit LCU; the unit LCU is used to judge the working state of the unit and output control commands to the PLC controller according to the working state. The data signal input end of the unit LCU is connected to the data signal output end of the acquisition module, and the control signal output end of the unit LCU is connected to the control signal input end of the PLC controller.

[0049] The unit LCU includes a central controller, a human-machine interface, a data analysis module, and a logic judgment module. The central controller is used to receive the command signals input by the human-machine interface, receive the logic judgment results, and send command signals to the PLC controller. The data analysis module is used to calculate the difference between the set value of active power or the active power regulation target value and the actual active power, and calculate the action amount of the guide vane opening according to the primary frequency regulation action frequency difference. The logic judgment module is used to judge the size relationship between the difference and the control dead zone range, whether the primary frequency regulation acts, and whether the active power setting command of the unit LCU is valid. The signal end of the human-machine interface is connected to the signal end of the central controller, the signal end of the data analysis module is connected to the signal end of the central controller, the data signal output end of the logic judgment module is connected to the data signal input end of the central controller, and the control signal output end of the central controller is connected to the control signal input end of the PLC controller.

[0050] The control system further includes an active power transmitter, which is used to measure the active power of the unit and isolate and transmit the active power into a linear DC analog signal. The data signal output end of the active power transmitter is connected to the data signal input end of the acquisition module.

[0051] The active power transmitter measures the active power of the unit, transmits it as a linear DC analog signal to the acquisition module. The acquisition module acquires the primary frequency regulation action signal of the governor, and transmits the primary frequency regulation action signal and the currently received actual active power to the unit LCU. The logic judgment module judges whether the primary frequency regulation acts and whether the active power setting command of the unit LCU is valid, and transmits the judgment result to the central controller and the data analysis module. The data analysis module calculates the difference between the active power regulation target value and the current actual active power, the difference between the current active power set value and the current actual active power, or calculates the action amount of the guide vane opening according to the primary frequency regulation action frequency difference. The difference result or the action amount of the guide vane opening is transmitted to the central controller. The central controller transmits the difference result to the logic judgment module. The logic judgment module judges whether the difference result is within the control dead zone range, and outputs the judgment result to the central controller. The central controller outputs a control command to the PLC controller according to the judgment result or the action amount of the guide vane opening. The PLC controller controls the governor to make the guide vane actuator act to achieve the purpose of adjusting the guide vane opening.

[0052] The technical solution of the present invention is not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solution of the present invention falls within the protection scope of the present invention.

Claims

1. A control method for power closed-loop and primary frequency regulation of a hydropower station generator, characterized in that, It includes the following steps: S1. Collect the actual active power of the unit and the governor's primary frequency regulation action signal; S2. Judge whether the primary frequency regulation acts; if it acts, go to S3; if it does not act, go to S4; S3. Judge whether the active power setting command of the unit LCU is valid. If it is valid, make the active power regulation target value of the unit LCU equal to the current active power setting increment of the unit LCU + the actual active power value when the active power setting command of the unit LCU is valid, and go to S5. If it is not valid, the governor determines the guide vane opening action amount according to the current primary frequency regulation action frequency difference and returns to S2; S4. Judge whether the active power setting command of the unit LCU is valid. If it is valid, make the active power regulation target value of the unit LCU equal to the current active power setting value of the unit LCU and go to S5. If it is not valid, go to S6; S5. Judge the relationship between the active power regulation target value of the unit LCU and the current actual active power value of the unit and the control dead zone, send relevant control commands to the governor, and the governor controls the guide vane actuator to perform corresponding opening and closing actions until the active power regulation target value of the unit LCU and the current actual active power value of the unit are within the control dead zone, and restore the active power setting command. If entering S5 from S3, return to S3; If entering S5 from S4, return to S4; specifically including: S51. Judge whether the difference between the active power regulation target value of the unit LCU and the current actual active power value of the unit is greater than the maximum value of the control dead zone; S52. If so, send an open guide vane command to the governor and return to S51; if not, go to S53; S53. Judge whether the difference between the active power regulation target value of the unit LCU and the current actual active power value of the unit is less than the minimum value of the control dead zone; S54. If so, send a close guide vane command to the governor and return to S53; if not, go to S55; S55. If entering S5 from S3, return to S3; if entering S5 from S4, return to S4; S6. Judge the relationship between the current active power setting value of the unit LCU and the current actual active power value of the unit and the control dead zone, send relevant control commands to the governor, and the governor controls the guide vane actuator to perform corresponding opening and closing actions until the current active power setting value of the unit LCU and the current actual active power value of the unit are within the control dead zone; specifically including: S61. Judge whether the difference between the current active power setting value of the unit LCU and the current actual active power value of the unit is greater than the maximum value of the control dead zone; S62. If so, send an open guide vane command to the governor and return to S61; if not, go to S63; S63. Judge whether the difference between the current active power setting value of the unit LCU and the current actual active power value of the unit is less than the minimum value of the control dead zone; S64. If so, send a close guide vane command to the governor and return to S63; if not, end; 2. A control system for the power closed-loop and primary frequency regulation of a hydropower station generator, which is used to implement the control method for the power closed-loop and primary frequency regulation of a hydropower station generator described in claim 1, characterized in that, It includes: A collection module; The collection module is used to collect the actual active power of the unit and the governor's primary frequency regulation action signal; A governor for adjusting the guide vane opening; The control signal output end of the governor is connected to the control signal input end of the guide vane actuator; PLC controller; The PLC controller is used to control the working state of the governor, and the control signal output end of the PLC controller is connected to the control signal input end of the governor; Unit LCU; the unit LCU is used to judge the working state of the unit and output a control command to the PLC controller according to the working state. The data signal input end of the unit LCU is connected to the data signal output end of the acquisition module, and the control signal output end of the unit LCU is connected to the control signal input end of the PLC controller.

3. The control system for power closed-loop and primary frequency regulation of a hydropower station generator according to claim 2, characterized in that, The unit LCU includes a central controller, a human-machine interface, a data analysis module and a logic judgment module. The central controller is used to receive the command signal input by the human-machine interface, receive the logic judgment result, and send the command signal to the PLC controller. The data analysis module is used to calculate the difference between the set value of active power or the active power regulation target value and the actual active power, and calculate the guide vane opening action amount according to the primary frequency modulation action frequency difference. The logic judgment module is used to judge the magnitude relationship between the difference and the control dead zone range, whether the primary frequency modulation acts, and whether the active power setting command of the unit LCU is valid. The signal end of the human-machine interface is connected to the signal end of the central controller, the signal end of the data analysis module is connected to the signal end of the central controller, the data signal output end of the logic judgment module is connected to the data signal input end of the central controller, and the control signal output end of the central controller is connected to the control signal input end of the PLC controller.

4. The control system for the power closed-loop and primary frequency regulation of a hydropower station generator according to claim 2 or 3, characterized in that, The control system also includes an active power transmitter, which is used to measure the active power of the unit and isolate and transmit the active power into a linear DC analog signal. The data signal output end of the active power transmitter is connected to the data signal input end of the acquisition module.

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