Standardization implementation method for LCU sequence control process module of pumped storage unit

Abstract

The invention discloses a standardized implementation method for an LCU sequence control process module of a pumped storage unit. A working condition conversion structure chart is drawn according to working condition characteristics of the controlled unit; compiling control programs for subprograms in the normal conversion flow chart and the accident conversion flow chart by using an SFC sequence function flow chart programming language; the program is subjected to modularization and segmentation processing; and calling each subprogram by using the main program according to the conversion requirement. The mutual conversion process of various working conditions of the pumping and storage unit is decomposed into a plurality of sequential control flow subprograms, then the subprograms are called one by one according to the working condition conversion requirement through a main program, standard subprograms are called for multiple times, the program occupied space can be reduced, the error rate can be reduced, and the complex control program has the advantages of distinct hierarchy, clear logic and high efficiency. And for maintenance personnel, troubleshooting and fault positioning are rapid.

Description

Technical Field

[0001] The invention belongs to the technical field of unit control and relates to a method for standardizing an LCU sequential control process module of a pumped storage unit. Background Art

[0002] Compared with conventional hydroelectric generating units, pump-turbine units in pumped-storage power stations have more operating conditions and more complex operating condition conversion. Conventional hydroelectric generating units have only four steady-state operating conditions in one rotation direction, while pumped-storage units have nine steady-state operating conditions in two directions and four transient operating conditions, and the operating condition conversion process is more complex. Pumped-storage units play the role of peak load regulation, valley filling, and emergency support in the power grid, and have very high requirements for the conversion speed of each operating condition.

[0003] Traditional unit control usually uses function block diagram (FBD), ladder diagram (LAD) and structured text (ST). Among them, function block diagram and ladder diagram belong to overall scanning and overall output type. Use different signal logic combinations to achieve sequential control of unit processes. As long as the signal meets the logic, the control can be output. Because the same signal may be used for control judgment of other devices many times, it is easy to cause the control sequence to be disordered due to signal instability. Some will use a large number of signal delays and more complex signal logic to maintain the stability of the control sequence, which will cause slow program execution and more complex logic. The structured text programming language is similar to the C language, not graphical programming, with poor readability, and troubleshooting requires more professional talents. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a standardized implementation method for the LCU sequential control process module of a pumped storage unit, which decomposes the process of mutual conversion of various working conditions of the pumped storage unit into a number of sequential control process subroutines, and then calls the subroutines one by one according to the working condition conversion requirements through the main program. The standard subroutines are called multiple times, which can not only reduce the space occupied by the program and reduce the error rate, but also make the complex control program have distinct levels, clear logic, and easy reading and writing. For maintenance personnel, faults can be quickly detected and located.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for standardizing the LCU sequential control process module of a pumped storage unit, comprising the following steps: S1, draw the operating condition conversion structure diagram according to the operating condition characteristics of the controlled unit; including normal conversion flow chart and accident conversion flow chart; S2, using SFC sequential function flow chart programming language to write control programs for the subroutines in the normal conversion flow chart and the accident conversion flow chart; S3, modularize the program and process it in segments; use the main program to call each subprogram according to the conversion requirements.

[0006] In S1, the normal conversion flowchart and the accident conversion flowchart include multiple subroutines for conversion of different working conditions.

[0007] Use a table to number each subroutine and form a directory.

[0008] In S2, when the main program calls the subroutine CSQ01 variable, the subroutine enters the starting step. When the conditions are met, the auxiliary machine is turned on; when the conversion conditions are met, the speed regulator hydraulic lock is deactivated.

[0009] The subroutines include shutdown→shutdown hot standby, shutdown hot standby→idling, no-load→generation, generation→generation phase adjustment, generation phase adjustment→generation, generation→no-load, idling→no-load, no-load→idling, idling→rotation shutdown, generation phase adjustment→rotation shutdown, shutdown hot standby→SFC pumping phase adjustment, shutdown hot standby→SFC pumping phase adjustment, pumping phase adjustment→pumping, pumping→pumping phase adjustment, pumping→rotation shutdown, pumping phase adjustment→rotation shutdown, indeterminate state→rotation shutdown, emergency shutdown→rotation shutdown, mechanical accident→rotation shutdown, electrical accident→rotation shutdown, rotation shutdown→shutdown hot standby, shutdown hot standby→shutdown, shutdown hot standby→black start, black start→generation, shutdown hot standby→line charging and line charging→generation.

[0010] The main beneficial effects of the present invention are: Graphical programming has the advantages of clear structure, strong readability, high reliability, and easy debugging. It can sequence, modularize, and structure complex control processes.

[0011] The process of conversion between various working conditions of the pumped storage unit is decomposed into several sequential control process subroutines, and then the subroutines are called one by one through the main program according to the working condition conversion requirements. The standard subroutines are called multiple times, which can not only reduce the space occupied by the program and reduce the error rate, but also make the complex control program have distinct levels, clear logic, and easy reading and writing. For maintenance personnel, it is quick to troubleshoot and locate faults.

[0012] The characteristics of step control are that it is executed step by step in sequence, completing only one step task each time, and is not interfered by other signals. It can greatly improve the control reliability of the pumped storage unit and increase the success rate of starting and stopping. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0014] Figure 1 This is a flow chart of the normal operating condition conversion of the unit of the present invention.

[0015] Figure 2 This is a flow chart of the unit accident shutdown conversion of the present invention.

[0016] Figure 3This is a sequential control flow chart from shutdown to shutdown hot standby of the present invention. DETAILED DESCRIPTION

[0017] like Figure 1~Figure 3 A method for standardizing a sequential control process module of a pumped storage unit LCU comprises the following steps: S1, draw the operating condition conversion structure diagram according to the operating condition characteristics of the controlled unit; including normal conversion flow chart and accident conversion flow chart; S2, using SFC sequential function flow chart programming language to write control programs for the subroutines in the normal conversion flow chart and the accident conversion flow chart; S3, modularize the program and process it in segments; use the main program to call each subprogram according to the conversion requirements.

[0018] In a preferred solution, in S1, the normal conversion flowchart and the accident conversion flowchart include multiple subroutines for conversion of different working conditions.

[0019] In a preferred solution, each subroutine is numbered in a table to form a directory.

[0020] In the preferred solution, in S2, when the main program calls the subprogram variable, the subprogram enters the starting step, and when the conditions are met, the auxiliary machine is turned on; when the conversion conditions are met, the speed regulator hydraulic lock is deactivated.

[0021] In the preferred scheme, the subroutines include shutdown→shutdown hot standby, shutdown hot standby→idling, no-load→generation, generation→generation phase adjustment, generation phase adjustment→generation, generation→no-load, idling→no-load, no-load→idling, idling→rotation shutdown, generation phase adjustment→rotation shutdown, shutdown hot standby→SFC pumping phase adjustment, shutdown hot standby→SFC pumping phase adjustment, pumping phase adjustment→pumping, pumping→pumping phase adjustment, pumping→rotation shutdown, pumping phase adjustment→rotation shutdown, indeterminate state→rotation shutdown, emergency shutdown→rotation shutdown, mechanical accident→rotation shutdown, electrical accident→rotation shutdown, rotation shutdown→shutdown hot standby, shutdown hot standby→shutdown, shutdown hot standby→black start, black start→generation, shutdown hot standby→line charging and line charging→generation.

[0022] Embodiment 1, 1. Draw the working condition conversion structure diagram according to the working condition characteristics of the controlled unit, which is divided into the normal conversion flow chart, such as Figure 1 As shown; accident conversion flow chart, such as Figure 2 shown.

[0023] Figure 1 and Figure 2 The normal start-stop condition conversion process and the accident shutdown condition conversion process of the pumped storage unit are vividly drawn, and the serial numbers 1-27 represent the subroutines for different condition conversions: No. 1, shutdown → shutdown hot standby control process. It is the preparation process for the unit to enter operation. All target state startups need to call this control process. At least 10 startup target states need to call this submodule program. It is a prerequisite for the stable operation of the pump turbine unit.

[0024] No. 2, shutdown hot standby → idling control process. This process converts the unit from a stationary state to a rotating state in the power generation direction. This process is to test the mechanical performance of the generator.

[0025] No. 3, no-load → power generation control process. The key process of connecting the generator to the grid, after which it can provide green and clean energy to the grid.

[0026] Sequence No. 4, power generation → power generation phase adjustment control process. When the generator needs to be temporarily withdrawn or needs to provide better voltage regulation for the grid, the generator needs to be switched from the power generation condition to the power generation phase adjustment condition.

[0027] Sequence number 5, power generation phase adjustment → power generation control process. The process of ending power generation phase adjustment and continuing to provide power to the grid.

[0028] No. 6, power generation → no-load control process. The generator stops generating electricity and goes to the first step of shutdown. The main process is load unloading and circuit breaker opening to disconnect from the grid.

[0029] No. 7, idling → no-load control process. The process of switching the generator from idling operation to operation with rated voltage is used to test the electrical characteristics of the generator itself.

[0030] No. 8, no-load → idling control process. The generator changes from the state with rated voltage to the idling state, and the main operation is the inversion and voltage reduction of the excitation system.

[0031] No. 9, idling → rotation shutdown control process. The generator closes the water inlet guide vane, closes the ball valve, the generator loses power, and the speed slowly decreases.

[0032] No. 10, generation phase adjustment → rotation shutdown control process. The generation phase adjustment state is disconnected from the grid and the rotation speed slowly decreases.

[0033] No. 11, shutdown hot standby → SFC pumping phase adjustment (SFC1#) control process. The unit water pump direction is changed from SFC No. 1 dragging and grid connection to pumping phase adjustment operation when the auxiliary machine is turned on. This operation process is complex and requires 14 steps of operation. There are many operating equipment and it also involves the call of the inflation and water pressure subroutine. However, the execution order of each step must be strictly controlled. The advantage of sequential control is the stable control of each step of equipment operation.

[0034] The SFC here, static frequency changer, is the same as the abbreviation of SFC Sequential Function Chart, but the meaning is different.

[0035] No. 12, shutdown hot standby → SFC pumping phase adjustment (SFC2#) control process. Similar to No. 11, use SFC No. 2 to drag the unit in the direction of the water pump to connect to the grid.

[0036] No. 13, pumping phase adjustment → pumping control process. The unit switches from pumping phase adjustment to pumping state. This process requires multiple volutes to exhaust and fill water, open the ball valve, and wait for splashing water to build pressure before the governor opens the guide vane. The unit under water pumping condition enters the pumping stage.

[0037] No. 14, Pumping → Pumping Phase Adjustment Control Process. When the unit under the pumping condition needs to stop pumping or the whole plant needs to pump water, it can provide better voltage regulation for the power grid. When switching from pumping to pumping phase adjustment, the process of closing the guide vane, closing the ball valve, and charging the turbine to pressurize water is executed.

[0038] No. 15, Pumping → Rotation Shutdown Control Process. The unit is shut down under pumping conditions, and the guide vanes are closed to reduce the load, the generator outlet switch is disconnected, the excitation system is inverter-demagnetized, and the ball valve is closed.

[0039] No. 16, pumping phase adjustment → rotation shutdown control process. Pumping phase adjustment turns to shutdown, and executes reactive power decoupling, generator outlet switch, excitation system inversion, high-top start and other operations in sequence.

[0040] No. 17, Unstable state → Rotation shutdown control process. The unit is shut down when the state is unclear.

[0041] No. 18, emergency shutdown → rotation shutdown control process. In case of emergency, the unit will be shut down, and the guide vanes and ball valves will be quickly closed to complete the unit decoupling, disconnect the circuit breaker, disconnect the demagnetization switch, etc.

[0042] No. 19, Mechanical Accident → Rotation Shutdown Control Process. When the unit encounters a mechanical accident, it will be shut down. Quickly close the guide vanes to complete the unit decoupling, disconnect the circuit breaker, disconnect the demagnetization switch, close the ball valve, etc.

[0043] No. 20, electrical accident → rotation shutdown control process. Similar to emergency accidents, directly dump the load and outlet switch, quickly close the guide vane and ball valve, etc.

[0044] No. 21, rotary shutdown → shutdown hot standby control process. In the rotary shutdown to shutdown hot standby process, under normal circumstances, the electric brake is put into operation at 50% speed, and the magnetic field damping is used to quickly reduce the unit speed. The mechanical brake is put into operation at 5% speed. In the case of an accident, the rotary shutdown will not be put into operation. The mechanical brake is put into operation at 10% speed to quickly reduce the unit speed.

[0045] No. 22, shutdown hot standby → shutdown control process. From shutdown hot standby to shutdown, the last step of the shutdown process is to stop the auxiliary equipment of the unit.

[0046] No. 24, shutdown hot standby → black start control process. Black start is the start-up process when the power grid has collapsed due to a serious fault and the generator needs to be started as the first support point of the power grid. This process is different from the normal grid connection of the normal generator. The unit uses the self-provided diesel generator in the factory as the starting power supply to start the auxiliary system. After the unit speed reaches the rated speed, the generator output circuit breaker is closed. After the circuit breaker is closed, the excitation system can self-excite and boost the voltage to supply power to the power grid, which serves as the first support point of the power grid.

[0047] No. 25, black start → power generation control process. After the black start process is completed and the power grid fault is restored, the unit can switch from black start operation to normal power generation operation.

[0048] Sequence number 26, shutdown hot standby → line charging control process. Similar to sequence number 24 black start.

[0049] Sequence number 27, line charging → power generation control process. Similar to sequence number 25.

[0050] Embodiment 2, The sub-processes corresponding to the serial numbers in Example 1 are drawn into a directory table, as shown in the following table.

[0051]

[0052] According to the design, each sub-process is written into a control program using the SFC (Sequential Function Chart) sequential function flow chart programming language. Take the CSQ01 shutdown → shutdown hot standby control process as an example. Figure 3 As shown: Figure 3 It is a control program written in SFC (Sequential Function Chart) sequential function flow chart programming language. This programming language is graphical programming with strong readability and stable operation. It only allows execution in step sequence and is particularly suitable for process control flow programming that is executed in sequence.

[0053] Figure 3 In the program, the program is the shutdown state → shutdown hot standby sequential control process (ST → TS): 1. Start the auxiliary machines: including technical water supply, external circulation oil system, oil mist absorption device, carbon powder absorption device, spindle sealing water and high-pressure oil jacking.

[0054] 2. Reverse the hydraulic lock of the speed regulator.

[0055] CSQ01_STEP0 is the initial step of the sequential control process. When the main program calls the variable name CSQ01 of the subroutine, the initial step of the program is activated.

[0056] CSQ01_T1 is a conversion component, which is used to connect process steps. When the previous step is triggered, it starts to monitor the judgment conditions embedded in the conversion component. When the conditions are met, the next step of the program can be activated.

[0057] CSQ01_STEP1 is an execution step. This component embeds execution variables and can execute corresponding process operations after activation.

[0058] There is a branch component between CSQ01_STEP1 and CSQ01_T2. When there are multiple results of the execution of the previous process step, it switches to different branch processes according to different results.

[0059] CSQ01_STEP2 is a jump component, which is used to jump to the specified process step in a specific program.

[0060] Figure 3 The operation process of the control program is as follows: When the main program calls the subroutine variable CSQ01, the subroutine enters the starting step CSQ01_STEP0. When the CSQ01_T1 condition is met, the program enters CSQ01_STEP1, starts the auxiliary machine, starts the technical water supply, the external oil cooling system, the oil mist absorption device, the carbon powder absorption device, the spindle sealing water, the high-pressure oil jacking and other equipment, and waits for the execution result. When the conversion conditions CSQ01_T2 or CSQ01_T21 are met, the program enters CSQ01_STEP2, executes the deactivation of the hydraulic lock of the speed regulator, waits for the execution result, and the relay lock exit is fed back to CSQ01_T3, and the process ends. The program automatically returns to the starting step and waits for a new main program call.

[0061] In the above embodiment 2, only the CSQ01 shutdown → shutdown hot standby control process is taken as an example to briefly explain the operation process of the SFC sequential control process. The entire pumped storage control process has nearly 30 conversion processes and nearly 200 process step controls. In this way, the use of modular and step-by-step programming can ensure the stability of the step sequence and prevent step skipping and disordered sequential control. The stability of the control process improves the safety of the equipment and the success rate of startup and shutdown.

[0062] Embodiment 3, After editing each subprogram, use the main program to call each subprogram according to the conversion requirements. The conversion call list of each working condition is as follows:

[0063] Another highlight of the patented method is to modularize and segment the program, and then use the main program to call the subprogram according to the operation target. For example, in the process of pumping water to power generation, the main program needs to call the subprograms CSQ15 pumping water to rotation shutdown, CSQ21 rotation shutdown to shutdown hot standby, CSQ02 shutdown hot standby to idling, CSQ07 idling to no-load, and CSQ03 no-load to power generation in sequence. This can reduce the writing of programs, save program resources, and improve the utilization efficiency of programs. Clearer logic can also improve maintenance efficiency.

[0064] In the above method, for the control of highly complex equipment such as pumped storage power stations, the sequential control process programming language SFC is used to modularize and standardize the control of the pump turbine of the pumped storage power station, and then the main program is used to call the subroutine block according to the design according to the working condition conversion requirements. Make the control program clear in structure, clear in logic, and easy to read and write. Execute the program in sequence, and the control sequence of the control equipment is more accurate. Compared with conventional logic control languages, there will be no errors in the execution sequence due to unstable signals. Step-by-step execution does not require a comprehensive scan of all logic, and does not require adding delays or more complex logic to maintain the stability of the sequential control process. The conversion of various working conditions of the unit can be achieved faster and more stably.

[0065] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for standardizing the LCU sequential control process module of a pumped storage unit, characterized by: The steps include: S1, draw the operating condition conversion structure diagram according to the operating condition characteristics of the controlled unit; including normal conversion flow chart and accident conversion flow chart; S2, using SFC sequential function flow chart programming language to write control programs for the subroutines in the normal conversion flow chart and the accident conversion flow chart; S3, modularize the program and process it in segments; use the main program to call each subprogram according to the conversion requirements.

2. The method for standardizing the LCU sequential control process module of a pumped storage unit according to claim 1 is characterized in that: In S1, the normal conversion flowchart and the accident conversion flowchart include multiple subroutines for conversion of different working conditions.

3. The method for standardizing the LCU sequential control process module of a pumped storage unit according to claim 2 is characterized in that: Use a table to number each subroutine and form a directory.

4. The method for standardizing the LCU sequential control process module of a pumped storage unit according to claim 2 is characterized by: In S2, when the main program calls the subroutine CSQ01 variable, the subroutine enters the starting step. When the conditions are met, the auxiliary machine is turned on; when the conversion conditions are met, the speed regulator hydraulic lock is deactivated.

5. The method for standardizing the LCU sequential control process module of a pumped storage unit according to claim 2 is characterized by: The subroutines include shutdown→shutdown hot standby, shutdown hot standby→idling, no-load→generation, generation→generation phase adjustment, generation phase adjustment→generation, generation→no-load, idling→no-load, no-load→idling, idling→rotation shutdown, generation phase adjustment→rotation shutdown, shutdown hot standby→SFC pumping phase adjustment, shutdown hot standby→SFC pumping phase adjustment, pumping phase adjustment→pumping, pumping→pumping phase adjustment, pumping→rotation shutdown, pumping phase adjustment→rotation shutdown, indeterminate state→rotation shutdown, emergency shutdown→rotation shutdown, mechanical accident→rotation shutdown, electrical accident→rotation shutdown, rotation shutdown→shutdown hot standby, shutdown hot standby→shutdown, shutdown hot standby→black start, black start→generation, shutdown hot standby→line charging and line charging→generation.

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