Primary frequency modulation and AGC locking assessment optimization method

Abstract

The invention provides a primary frequency modulation and AGC locking assessment optimization method, and belongs to the technical field of power station operation control. According to the method, a primary frequency modulation monitoring program is added in an LCU program, and when the primary frequency modulation action exceeds 3 seconds, a load set value tracks a load average value 10 seconds before the primary frequency modulation action. And if not more than 3 seconds, the load instruction tracks the secondary frequency modulation instruction. If the primary frequency modulation action is not enough for 60s after locking, the total locking time is 60s; and when the primary frequency modulation action exceeds 60s and the primary frequency modulation action signal is reset, the locking function of the primary frequency modulation on the AGC is immediately released. By applying the method, the reverse modulation condition of primary frequency modulation can be fully avoided, the control efficiency is improved, and the method has outstanding technical advantages and good operation performance.

Description

Technical Field

[0001] The invention belongs to the technical field of power station operation control, and specifically relates to a primary frequency modulation and AGC interlocking assessment optimization method. Background Art

[0002] Primary frequency regulation refers to the automatic control process in which the control system of the units in the power grid automatically controls the increase or decrease of the active power of the units, limits the change of the power grid frequency, and maintains a stable power grid frequency once the power grid frequency deviates from the rated value.

[0003] On February 17, 2024, the applicant generated a frequency regulation assessment: Unit 1 was 60,636.76 yuan, Unit 2 was 65,884.96 yuan, Unit 3 was 36,477.68 yuan, and Unit 4 was 40,632.66 yuan. The assessment occurred during the period from 21:32 to 21:40 on February 17. The operation of all units was that Units 1, 2, 3, and 4 were generating electricity. The period from 21:30 to 21:45 was the load reduction shutdown of Unit 3. The unit shutdown priority order was 3.2.4.1.

[0004] During the load reduction and shutdown process of Unit 3, when the load dropped to 220MW, the grid frequency dropped to 49.92Hz. At 21:33:57, the frequency regulation of all four units was activated. After the frequency regulation was activated, the actual power of Units 1 and 4 reached 306MW, which lasted for 11 seconds until 21:34:08 when the frequency regulation was restored. The AGC immediately distributed the load of the entire plant evenly to the four units, that is, the shutdown unit Unit 3 and the accompanying shutdown unit Unit 2 stopped reducing the load, and the power of Units 3 and 4, which were operating at normal full load of 300MW, was set to 280MW at the same time. After the frequency regulation was restored, the actual power values ​​of the four units immediately tracked the active power setting value of 280MW, and the actual power values ​​of the four units were all around 280MW. After that, the speed regulator was activated several times. At 21:35:25, the speed regulator activated once, and at 21:35:32, the speed regulator was reset once (this time the frequency regulation lasted for 7 seconds); at 21:35:47, the speed regulator activated once, and at 21:35:55, the speed regulator was reset once (this time the frequency regulation lasted for 8 seconds); at 21:37:32, the speed regulator activated once, and at 21:37:48, the speed regulator was reset once (this time the frequency regulation lasted for 16 seconds); at 21:37:56, the speed regulator activated once, and at 21:38:14, the speed regulator activated once The action is restored (this frequency regulation lasts for 18 seconds); at 21:38:20, the speed governor performs a frequency regulation action, and at 21:38:38, the speed governor performs a frequency regulation action and restores the action (this frequency regulation lasts for 18 seconds); at 21:38:45, the speed governor performs a frequency regulation action, and at 21:38:55, the speed governor performs a frequency regulation action and restores the action (this frequency regulation lasts for 10 seconds). After the last frequency regulation action, the four units no longer perform a frequency regulation adjustment, resulting in the load of the four units being maintained at 280MW. During this period, the output of the entire plant maintained the load value before the frequency regulation action at 21:33:57.

[0005] From the perspective of a single unit, at 21:33:57, units 1 and 4 were operating at full load of 300MW and a frequency adjustment was performed. After the low-frequency frequency regulation action, the actual power reached 306MW and the frequency regulation acted correctly. However, after the frequency regulation was restored, the AGC set the load distribution value of units 1 and 4 to 280MW, and the monitoring was not set to lock the load adjustment within 1 minute after the frequency regulation action. As a result, after the frequency regulation was restored at 21:34:08, the units tracked the set value of 280MW and operated until 21:44:06, when the GCB of unit 3 was opened. The load distribution value of units 1 and 4 became 300MW. Therefore, the integrated power of units 1 and 4 had a large deviation in these 10 minutes. Units 2 and 3 should have performed a frequency adjustment with actual load value during the primary frequency regulation action. At this time, the load of Unit 3 had dropped to 220MW, and the primary frequency regulation did not lock the load adjustment. The AGC set the load distribution value to 280MW, and the actual power of Unit 3 increased to 280MW. Unit 2 also tracked 280MW operation. At 21:40:00, the AGC shut down Units 2 and 3 to reduce the load and accompanied the shutdown to reduce the load. At 21:44:06, the GCB of Unit 3 was opened, and the load distribution value of Unit 2 was changed back to 300MW, resulting in a large deviation in the integrated power of Units 2 and 3 during this 6-minute period. Summary of the invention

[0006] The present invention aims to provide a method for optimizing primary frequency modulation and AGC locking assessment in view of the technical defects of the prior art, so as to solve the technical problem that the primary frequency modulation is prone to reverse modulation under the conventional method.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] The optimization method for the assessment of primary frequency regulation and AGC interlocking includes: at the LCU end, when the primary frequency regulation action event exceeds 3 seconds, the load setting value sent by the monitor tracks the load average value of the 10 seconds before the primary frequency regulation action; if it does not exceed 3 seconds, the load setting value tracks the secondary frequency regulation instruction; when the secondary frequency regulation interlocking is triggered, if the primary frequency regulation action time is less than 60 seconds, the secondary frequency regulation reverse adjustment instruction is interlocked for 60 seconds, if the primary frequency regulation action time exceeds 60 seconds, when the primary frequency regulation action signal is restored, the locking function of the primary frequency regulation on the secondary frequency regulation is immediately released.

[0009] Preferably, the method is implemented by a frequency modulation monitoring program in the LCU program.

[0010] Preferably, the method also includes: at the AGC end, ensuring that the load is redistributed evenly during a frequency modulation action due to the unit load fluctuation not exceeding a certain value; confirming the AGC source program's high-frequency locking load increase instruction and low-frequency locking load reduction instruction functions.

[0011] Preferably, the method also includes: at the speed regulator end, when a frequency modulation action immediately locks the load set value, the frequency modulation action resets within 3 seconds and the locking function is released; if it exceeds 3 seconds and is less than 60 seconds, it will continue to lock for 57 seconds, and when the frequency modulation action exceeds 60s and the frequency modulation action signal resets, the locking function of the frequency modulation on the AGC is immediately released.

[0012] Preferably, in the method, the blocking function is only performed above 145 MW.

[0013] Preferably, in the method, either the step at the LCU end or the step at the speed regulator end is started.

[0014] The present invention provides a method for optimizing the assessment of primary frequency modulation and AGC locking. The method adds a primary frequency modulation monitoring program to the LCU program. When the primary frequency modulation action exceeds 3 seconds, the load setting value tracks the load average value of the 10 seconds before the primary frequency modulation action. If it does not exceed 3 seconds, the load instruction tracks the secondary frequency modulation instruction. If the primary frequency modulation action after locking is less than 60s, the total locking duration is 60s; when the primary frequency modulation action exceeds 60s and the primary frequency modulation action signal is reset, the locking function of the primary frequency modulation on the AGC is immediately released. The application of the present invention can fully avoid the reverse modulation of the primary frequency modulation, improve the control efficiency, and has outstanding technical advantages and good operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of adding variables in Example 1 of the present invention.

[0016] Figure 2 It is a schematic diagram of Pid_Para increasing the value assigned to PFR_P_Min in Embodiment 1 of the present invention.

[0017] Figure 3 It is a schematic diagram of the function of PID_P shielding a frequency modulation action to exit PID regulation in embodiment 1 of the present invention.

[0018] Figure 4 It is a schematic diagram of the protection in which Pid_P adds a frequency modulation action to shield the unchanged regulation in embodiment 1 of the present invention.

[0019] Figure 5 It is a schematic diagram of a procedure related to frequency modulation processing added to Pid_P in Embodiment 1 of the present invention.

[0020] Figure 6 It is a schematic diagram of adding storage of P_Set_CCS data to Recv in Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in detail below. In order to avoid too much unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to have a certain change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meaning as those generally understood by those skilled in the art to which the present invention belongs.

[0022] Example 1

[0023] Optimization method for primary frequency modulation and AGC interlock assessment: add a primary frequency modulation monitoring program in the LCU program. When the primary frequency modulation action event exceeds 3 seconds, the load setting value issued by the monitor will track the load average value of the 10 seconds before the primary frequency modulation action; if it does not exceed 3 seconds, the load setting value will track the secondary frequency modulation instruction. When the secondary frequency modulation interlock is triggered, if the primary frequency modulation action time is less than 60 seconds, the secondary frequency modulation reverse adjustment instruction will be interlocked for 60 seconds. If the primary frequency modulation action time exceeds 60 seconds, when the primary frequency modulation action signal is restored, the primary frequency modulation interlock function on the secondary frequency modulation will be immediately released. In addition, due to program modification, the primary frequency modulation action protection and active power regulation value no change protection in the original PLC are modified accordingly.

[0024] The program modification process is as follows:

[0025] 1. Add variables (such as Figure 1 (shown)

[0026] 2. Program modification

[0027] 1) Pid_Para adds the value of PFR_P_Min (the primary frequency regulation blocking function is only executed above 145MW). (e.g. Figure 2 shown).

[0028] 2) PID_P shields the function of exiting PID regulation by primary frequency regulation (locking active regulation after primary frequency regulation protection action). Figure 3 shown).

[0029] 3) Pid_P adds a frequency regulation action to shield the protection of no change in regulation (the monitoring system is set with no change in measured value protection. After the unit is connected to the grid, during the active power regulation process, if the power measured value changes too little for 5 consecutive cycles (each cycle is 3s), the monitoring active power regulation will exit the power mode). (such as Figure 4 shown).

[0030] 4)Pid_P adds a frequency modulation processing related program. (such as Figure 5 shown).

[0031] Program meaning: If the primary frequency modulation action exceeds 3s, the load setting value tracks the load average value of 10s before the primary frequency modulation action; if the load instruction does not exceed 3s, it tracks the secondary frequency modulation instruction. If the primary frequency modulation action after blocking is less than 60s, the total blocking time is 60s; when the primary frequency modulation action exceeds 60s and the primary frequency modulation action signal is reset, the blocking function of the primary frequency modulation on AGC is immediately released.

[0032] 5) Recv adds storage for P_Set_CCS data. (e.g. Figure 6 shown).

[0033] Example 2

[0034] Primary frequency modulation and AGC interlock assessment optimization method, including:

[0035] 1. AGC: Optimize the load power distribution strategy to ensure that the load will not be redistributed evenly during a frequency regulation action due to excessive unit load fluctuations (without triggering load redistribution); confirm the AGC source program high-frequency locking load increase command and low-frequency locking load reduction command functions.

[0036] 2. LCU: When the frequency modulation action lasts for more than 3 seconds, the load setting value tracks the load average value of the 10 seconds before the frequency modulation action. The load command tracks the secondary frequency modulation command within 3 seconds. If the frequency modulation action lasts for less than 60 seconds after blocking, the total blocking time is 60 seconds; when the frequency modulation action lasts for more than 60 seconds and the frequency modulation action signal is restored, the blocking function of the frequency modulation on AGC is immediately released.

[0037] 3. Speed ​​governor: As long as the frequency modulation action is activated, the load setting value will be locked immediately. If the frequency modulation action is reset within 3 seconds, the locking function will be released. If it exceeds 3 seconds and is less than 60 seconds, the locking will continue for 57 seconds. When the frequency modulation action exceeds 60s and the frequency modulation action signal is reset, the locking function of the frequency modulation on the AGC will be immediately released (tracking the actual value of the electric modulation exchange meter).

[0038] Based on the above technical solutions:

[0039] 1. The above blocking function is only executed above 145MW.

[0040] 2. Only one of Optimization 2 and Optimization 3 is open.

[0041] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. Primary frequency modulation and AGC locking assessment optimization method, characterized in that: include: At the LCU end, when a frequency modulation action event exceeds 3 seconds, the load setting value sent by the monitoring device tracks the load average value of the 10 seconds before the frequency modulation action; If it does not exceed 3 seconds, the load setting value will track the secondary frequency regulation instruction; when the secondary frequency regulation interlock is triggered, if the primary frequency regulation action time is less than 60 seconds, the secondary frequency regulation reverse adjustment instruction will be interlocked for 60 seconds. If the primary frequency regulation action time exceeds 60 seconds, when the primary frequency regulation action signal is restored, the primary frequency regulation interlock function on the secondary frequency regulation will be immediately released.

2. The primary frequency modulation and AGC locking assessment optimization method according to claim 1 is characterized in that: The method is implemented by a frequency modulation monitoring program in the LCU program.

3. The primary frequency modulation and AGC locking assessment optimization method according to claim 1 is characterized in that: The method also includes: at the AGC end, ensuring that the load is redistributed evenly during a frequency modulation action due to the unit load fluctuation not exceeding a certain value; confirming the AGC source program high-frequency locking load increase instruction and low-frequency locking load reduction instruction functions.

4. The primary frequency modulation and AGC locking assessment optimization method according to claim 3 is characterized in that: The method also includes: at the speed regulator end, when a frequency modulation action immediately locks the load set value, the frequency modulation action resets within 3 seconds and the locking function is released; if it exceeds 3 seconds and is less than 60 seconds, it will continue to lock for 57 seconds. When the frequency modulation action exceeds 60s and the frequency modulation action signal resets, the locking function of the frequency modulation on the AGC is immediately released.

5. The primary frequency modulation and AGC locking assessment optimization method according to claim 4 is characterized in that: In this method, the blocking function is only performed above 145 MW.

6. The primary frequency modulation and AGC locking assessment optimization method according to claim 4 is characterized in that: In this method, either the step on the LCU side or the step on the speed regulator side is started.

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