A CCS instruction locking load adjustment method based on the primary frequency regulation effect

Abstract

The present invention discloses a CCS instruction locking load adjustment method based on the primary frequency modulation effect, comprising the following steps: calculating the ratio value DX of △QsY and △QjY; determining that the Y value interval is valid data if all the governor valve commands and feedback deviations of the steam turbines are < 1%; determining that the Y value interval is valid data if the main steam pressure is stable; determining that the Y interval is valid data if the AGC command maintains a stable time meeting the requirements; each curve segment corresponds to a unique Y value interval; obtaining n different Y intervals in the Ri segment; calculating to obtain the Y1 value; calculating the actual value Z; and determining whether the main control command M2 value should be locked through comparison of the increase and decrease direction of the main control command, the Z value, and the change value M of the main control command. The CCS instruction locking load adjustment method based on the primary frequency modulation effect of the present invention can provide auxiliary data support for the optimization adjustment of primary frequency modulation while not affecting the safe and stable operation of the unit itself.

Description

Technical Field

[0001] The invention relates to the technical field of primary frequency regulation of thermal power units, and in particular to a CCS instruction locking load adjustment method based on primary frequency regulation effect. Background Art

[0002] The primary frequency regulation of thermal power units is to use the thermal storage of the units to quickly adjust the load output according to the changes in the grid frequency, and ultimately achieve the purpose of stabilizing the grid frequency. The primary frequency regulation index of thermal power units is one of the important auxiliary services provided to the grid. The energy regulatory department rewards and punishes thermal power companies according to the performance of primary frequency regulation. If the primary frequency regulation performance does not meet the standard, it will face the assessment of electricity consumption.

[0003] According to the requirements of Appendix 1 of the Implementation Rules for Auxiliary Services Management of Grid-connected Power Plants in East China, the dead zone of thermal power units in conventional digital electro-hydraulic regulation and control systems shall be controlled within ±0.033Hz; the speed inequality rate δ% shall be 4% to 5%.

[0004] The performance index of primary frequency modulation effect refers to the ratio of actual action integrated electricity (±△QsY) to theoretically calculated integrated electricity (±△QjY) within the corresponding time, that is, DX=△QsY / △QjY, and the assessment index value is 0≤DX≤2 (when DX<0, then: DX=0; DX>2, then: DX=2).

[0005] According to Article 7 of the Implementation Rules for Auxiliary Services Management of Grid-connected Power Plants in East China, if the primary frequency regulation response behavior does not meet the requirements, it shall be assessed according to two situations. The first situation is the assessment when single DX>0 and ︱60%△QjY︱-︱△QsY︱>0, which means that although the load direction of the primary frequency regulation is correct, the actual action integral is less than 60% of the theoretical integral requirement; the second situation is the assessment of DX=0, which means that the actual action load of the primary frequency regulation is in the opposite direction to the theoretical required action load.

[0006] In the actual operation of the unit, due to the inherent delay characteristics of the turbine throttle and other actuators, the nonlinear characteristics caused by the sticking of the throttle and the change in flow characteristics, the primary frequency regulation performance may not respond in time in a certain section or several valve position sections. The frequency regulation performance should be recorded and corrected through the comprehensive valve position and flow section recording module.

[0007] At present, the domestic research direction on optimizing the reverse blocking value of primary frequency modulation and AGC commands under large frequency differences focuses on using DCS real-time data to manually analyze whether the action amplitude of primary frequency modulation and the integrated power consumption during the corresponding time period meet the requirements of grid assessment standards, and calculating the reverse margin of primary frequency modulation relative to AGC commands under large frequency differences. This margin is a fixed value. In terms of methods, insufficient attention is paid to the tracking of flow commands in different throttle segments, and the guiding role of big data on the statistical performance indicators of primary frequency modulation in analyzing the characteristics of primary frequency modulation is not emphasized, and DX data cannot be effectively mined, resulting in inaccurate blocking load values.

[0008] Based on the above situation, the present invention proposes a method for adjusting the blocking load of CCS commands based on the effect of primary frequency modulation, which can effectively solve the above problems. Summary of the Invention

[0009] The purpose of the present invention is to provide a method for adjusting the blocking load of CCS commands based on the effect of primary frequency modulation. The method for adjusting the blocking load of CCS commands based on the effect of primary frequency modulation of the present invention is convenient to use, and it can provide auxiliary data support for the optimization and adjustment of primary frequency modulation while not affecting the safe and stable operation of the unit itself.

[0010] The present invention is realized through the following technical solutions:

[0011] A method for adjusting the blocking load of CCS commands based on the effect of primary frequency modulation includes the following steps:

[0012] Step S1: Adjust the blocking load of CCS system commands through an adjustment system. The adjustment system consists of a primary frequency modulation reverse load calculation module, a high-pressure valve command feedback shielding module, a steam pressure deviation shielding module, an AGC command fluctuation shielding module, and a comprehensive valve position flow segment recording module;

[0013] Step S2: Under a preset large frequency difference, the CCS and the primary frequency modulation reverse load calculation module calculate the ratio value DX of the actual action component △QsY of primary frequency modulation at the network-source platform end and the theoretical integral quantity △QjY required by the network-source system according to the single primary frequency modulation action situation. The formula is:

[0014]

[0015] Step S3: The high-pressure valve command feedback shielding module determines whether the deviation between all high-pressure valve commands and feedbacks of the currently operating unit is <1%;

[0016] Step S4: The steam pressure deviation shielding module determines the stability of the main steam pressure from 10 s before the frequency modulation action to the moment of the frequency modulation action;

[0017] Step S5: In the AGC command fluctuation shielding module, it is judged whether the time for the AGC command to remain stable meets the requirements;

[0018] Step S6: Calculate the Y1 value by synthesizing n different interval values in the valve position flow rate segment Ri segment.

[0019] Step S7: During the large frequency deviation primary frequency regulation action time of the thermal power unit, if the CCS system to the turbine master control instruction M2 value reduces the load instruction at this time, and the primary frequency regulation action requires an increased load instruction, judge the locking situation of M2.

[0020] Step S8: During the large frequency deviation primary frequency regulation action time of the thermal power unit, if the CCS system to the turbine master control instruction M2 value increases the load instruction at this time, and the primary frequency regulation action requires a reduced load instruction, judge the locking situation of M2.

[0021] The purpose of the present invention is to provide a CCS instruction locking load adjustment method based on the primary frequency regulation effect. The CCS instruction locking load adjustment method based on the primary frequency regulation effect of the present invention is convenient to use, and it can provide auxiliary data support for the optimization and adjustment of primary frequency regulation while not affecting the safe and stable operation of the unit itself.

[0022] Preferably, the step 2 includes

[0023] Step S21: When DX < 1, define the Y value as zero at this time, and judge that when the reverse turbine master control instruction from the CCS is triggered, immediately lock the turbine master control unchanged to ensure the accurate action of primary frequency regulation.

[0024] Step S22: When DX ≥ 1, calculate the interval value of Y, and the formula is:

[0025] ︱△QsY - Y×t︱ - ︱β%×△QjY︱ > 0,

[0026] where t is the primary frequency regulation action duration, β% is the non - assessment value of the primary frequency regulation performance index, the positive and negative directions of Y and △QsY are opposite, and the positive and negative directions of △QsY - Y×t and △QjY are the same.

[0027] Preferably, the step 3 includes

[0028] Step S31: If all the high - lift instructions and feedback deviations are < 1%, then consider the Y interval as valid data and proceed to the next step;

[0029] Otherwise, consider the Y interval as invalid data and do not enter the calculation.

[0030] Preferably, the step 4 includes

[0031] Step S41: When the actual fluctuation range of the main steam pressure within the first 10 s before the moment of primary frequency modulation calculation is less than the fluctuation range corresponding to the unit capacity, it indicates that the boiler load and the turbine power are dynamically matched at this time. Then, it is considered that the Y interval calculated at this time is valid data, and the next step is entered;

[0032] Otherwise, it is considered that the Y interval is invalid data and does not enter the calculation.

[0033] Preferably, the said step 5 includes

[0034] Step S51: If the AGC command remains stable for a time ≥ 10 minutes under the condition that the change rate of the AGC command < 1% Pe / min before the moment of primary frequency modulation calculation, then the Y interval is valid data, and the next step is entered;

[0035] Otherwise, it is considered that the Y interval is invalid data and does not enter the calculation.

[0036] Preferably, the said step 6 includes

[0037] Step S61: According to the inflection points of the comprehensive valve position flow curve of the steam turbine unit, the Y value is corresponded to the straight line between every two inflection points, that is, each section of the curve corresponds to a unique Y interval;

[0038] Step S62: Obtain n different Y intervals in the comprehensive valve position flow section Ri within a period of time T;

[0039] Step S63: Preset the proportion of the Y value interval covered as S, and calculate the Y1 value, which can satisfy the Y value interval range of more than S proportion in the comprehensive valve position flow section Ri;

[0040] Step S64: Calculate the actual value Z, and the formula is:

[0041] Z = Y1 × K;

[0042] where K is the adaptation gain coefficient of the CCS system command.

[0043] Preferably, the said step S7 includes

[0044] Step S71: When M < Z, keep the turbine main control command M2 changing with the AGC command;

[0045] Step S72: When M ≥ Z, the turbine main control command M2 is locked and does not move.

[0046] Preferably, the said step S8 includes

[0047] Step S81: When M ≥ Z, keep the turbine main control command changing with the AGC command;

[0048] Step S82: When M < Z, the turbine main control command is locked and does not move.

[0049] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0050] The CCS instruction blocking load adjustment method based on the primary frequency modulation effect of the present invention is easy to use. It can provide auxiliary data support for the optimization and adjustment of primary frequency modulation while not affecting the safe and stable operation of the unit itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow block diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the preferred implementation modes of the present invention will be described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be construed as a limitation to this patent; for better illustration of this embodiment, some components in the drawings will be omitted, enlarged or reduced, and do not represent the actual size of the product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as a limitation to this patent.

[0053] Embodiment 1:

[0054] As Figure 1 shown, a CCS instruction blocking load adjustment method based on the primary frequency modulation effect includes the following steps:

[0055] Step S1: Adjust the CCS system instruction blocking load through an adjustment system. The adjustment system consists of a primary frequency modulation reverse load calculation module, a high-pressure instruction feedback shielding module, a steam pressure deviation shielding module, an AGC instruction fluctuation shielding module, and a comprehensive valve position flow segment recording module;

[0056] Step S2: Under a preset large frequency difference, the CCS and the primary frequency modulation reverse load calculation module calculate the proportional value DX of the actual action component △QsY of the primary frequency modulation at the network-source platform end and the theoretical integral quantity △QjY required by the network-source system according to the single primary frequency modulation action condition. The formula is:

[0057]

[0058] Based on the deviation between the proportional value DX and the required value of the primary frequency modulation assessment rules of each regional power grid, calculate and generate a margin Y that can reverse the CCS instruction. The Y value is the deviation value between the actual value of the turbine main control and the command value of the turbine main control.

[0059] The preset large frequency difference f is a break point at 2.0 - 3.0 r / min or -3.0 - -2.0 r / min, and can be set to 2.8 r / min;

[0060] Step S3: Determine whether the deviation between all high-pressure regulating commands and feedback of the currently operating unit is < 1% through the high-pressure regulating command feedback shielding module;

[0061] Step S4: Determine the stability of the main steam pressure from 10 s before the frequency regulation action to the instant of the frequency regulation action through the steam pressure deviation shielding module;

[0062] According to the numerical settings specified in DL / T 774 "Maintenance Regulations for Thermal Automation Systems in Fossil-Fuel Power Plants", the main steam pressure fluctuation range of 300 MW-class units is ±0.5 MPa, and that of 600 MW-class units is ±0.6 MPa.

[0063] Step S5: In the AGC command fluctuation shielding module, determine whether the time for the AGC command to remain stable meets the requirements;

[0064] Step S6: Calculate the value of Y1 by synthesizing n different interval values in the comprehensive valve position flow segment Ri segment;

[0065] Step S7: During the large frequency difference primary frequency regulation action time of the thermal power unit, if the CCS system reduces the load command to the turbine master control command M2 value at this time, and the primary frequency regulation action requires an increased load command, determine the locking situation of M2;

[0066] Step S8: During the large frequency difference primary frequency regulation action time of the thermal power unit, if the CCS system increases the load command to the turbine master control command M2 value at this time, and the primary frequency regulation action requires a reduced load command, determine the locking situation of M2.

[0067] Further, in another embodiment, the said step 2 includes

[0068] Step S21: When DX < 1, define the Y value as zero at this time, and determine that when the reverse turbine master control command from the CCS triggers, immediately lock the turbine master control unchanged to ensure the accurate operation of the primary frequency regulation;

[0069] Step S22: When DX ≥ 1, calculate the interval value of Y, and the formula is:

[0070] ︱△QsY - Y×t︱ - ︱β%×△QjY︱ > 0,

[0071] where t is the duration of the primary frequency regulation action, β% is the non-assessment value of the primary frequency regulation performance index, Y and △QsY have opposite positive and negative directions, and △QsY - Y×t and △QjY have the same positive and negative directions.

[0072] β% is 60% according to the "Implementation Rules for Auxiliary Service Management of Grid-Connected Power Plants in East China Region";

[0073] Further, in another embodiment, step 3 includes

[0074] Step S31: If all high-profile instructions and feedback deviations are < 1%, then the Y interval is considered valid data, and proceed to the next step;

[0075] Otherwise, the Y interval is considered invalid data and does not enter the calculation.

[0076] Further, in another embodiment, step 4 includes

[0077] Step S41: When the actual fluctuation range of the main steam pressure is less than the fluctuation range corresponding to the unit capacity within 10 s before the moment of primary frequency modulation calculation, it indicates that the boiler load and turbine power are dynamically matched at this time. Then, the Y interval calculated at this time is considered valid data, and proceed to the next step;

[0078] Otherwise, the Y interval is considered invalid data and does not enter the calculation.

[0079] Further, in another embodiment, step 5 includes

[0080] Step S51: If the AGC command remains stable for ≥ 10 minutes in the state where the AGC command change rate < 1% Pe / min before the moment of primary frequency modulation calculation, then the Y interval is valid data, and proceed to the next step;

[0081] Otherwise, the Y interval is considered invalid data and does not enter the calculation.

[0082] According to the requirements of Article 5.1 of DL / T 657-2015 "Acceptance Test Regulations for Analog Control Systems in Thermal Power Plants", the AGC command change rate < 1% Pe / min. Then, according to the requirements of Annex 2 of "Implementation Rules for Auxiliary Service Management of Grid-connected Power Plants in East China Region", if the AGC command remains stable for 10 minutes, the Y interval calculated at this time is used as valid data.

[0083] Further, in another embodiment, step 6 includes

[0084] Step S61: Based on the inflection points of the comprehensive valve position flow curve of the steam turbine unit, the Y interval is corresponded to the straight line between every two inflection points, that is, each curve segment corresponds to a unique Y interval;

[0085] Step S62: Obtain n different Y value intervals in the comprehensive valve position flow segment Ri within a period of time T;

[0086] Step S63: Preset the proportion of the covered Y value interval as S, and calculate the Y1 value, which can satisfy the range of more than S proportion of the Y value intervals in the comprehensive valve position flow segment Ri;

[0087] Step S64: Calculate the actual value Z using the formula:

[0088] Z = Y1 × K;

[0089] where K is the adaptation gain coefficient of the CCS system instruction.

[0090] The value range of Y1 is the theoretical limit value, so it is necessary to increase the adaptation gain coefficient; T can be set to 360h, S to 85%, and K to 1.05.

[0091] Furthermore, in another embodiment, the step S7 includes

[0092] Step S71: When M < Z, keep the turbine master control instruction M2 changing with the AGC instruction;

[0093] Step S72: When M ≥ Z, lock the turbine master control instruction M2 and keep it unchanged.

[0094] Furthermore, in another embodiment, the step S8 includes

[0095] Step S81: When M ≥ Z, keep the turbine master control instruction changing with the AGC instruction;

[0096] Step S82: When M < Z, lock the turbine master control instruction and keep it unchanged.

[0097] Based on the description and drawings of the present invention, those skilled in the art can easily manufacture or use the CCS instruction locking load adjustment method based on the primary frequency modulation effect of the present invention, and can produce the positive effects recorded in the present invention.

[0098] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. 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. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for exemplary illustration and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood in combination with the drawings and according to specific circumstances.

[0099] Unless otherwise clearly specified and defined, in the present invention, if there are terms such as "arranged", "connected" and "coupled", they should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. 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 situations.

[0100] As described above, the above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A CCS instruction blocking load adjustment method based on the primary frequency regulation effect, characterized in that It includes the following steps: Step S1: Adjust the locked load of the CCS system instructions through an adjustment system, which consists of a primary frequency regulation reverse load calculation module, a high-pressure governor command feedback shielding module, a steam pressure deviation shielding module, an AGC command fluctuation shielding module, and a comprehensive valve position flow segment recording module; Step S2: Under a preset large frequency difference, the CCS and the primary frequency regulation reverse load calculation module calculate the proportional value DX of the actual action component △QsY of the primary frequency regulation at the network-source platform end and the theoretical integral quantity △QjY required by the network-source system according to the single primary frequency regulation action condition. The formula is: ； The said step 2 includes Step S21: When DX < 1, define the Y value as zero at this time. Judge that when the reverse turbine master control command from the CCS triggers, immediately lock the turbine master control unchanged to ensure the accurate action of the primary frequency regulation; Step S22: When DX ≥ 1, calculate the interval value of Y. The formula is: ， Where, t is the duration of the primary frequency regulation action, β% is the non-assessment value of the primary frequency regulation performance index, the positive and negative directions of Y and △QsY are opposite, and the positive and negative directions of △QsY - Y×t and △QjY are the same; Step S3: Judge whether the deviation between all high-pressure governor commands and feedback of the currently operating unit is < 1% through the high-pressure governor command feedback shielding module; Step S4: Judge the stability of the main steam pressure from 10 s before the frequency regulation action to the moment of the frequency regulation action through the steam pressure deviation shielding module; Step S5: Judge whether the holding time of the AGC command reaches the requirement in the AGC command fluctuation shielding module; Step S6: Calculate the Y1 value by integrating n different interval values in the comprehensive valve position flow segment Ri segment; The said step 6 includes Step S61: Based on the inflection points of the comprehensive valve position flow curve of the steam turbine unit, correspond the Y value to the straight line between every two inflection points, that is, each curve segment corresponds to a unique Y interval; Step S62: Obtain n different Y intervals in the comprehensive valve position flow segment Ri segment through a period of time T; Step S63: Preset the proportion of the Y value interval covered as S, and calculate the Y1 value, which can meet the Y value interval range of more than S proportion in the comprehensive valve position flow segment Ri segment; Step S64: Calculate the actual value Z. The formula is: ； Where, K is the adaptation gain coefficient of the CCS system instruction; Step S7: During the large frequency difference primary frequency regulation action time of the thermal power unit, if the CCS system reduces the load command to the turbine master control command M2 value at this time, and the primary frequency regulation action requires an increased load command, judge the locking situation of M2; Step S8: During the large frequency difference primary frequency regulation action time of the thermal power unit, if the CCS system increases the load command to the turbine master control command M2 value at this time, and the primary frequency regulation action requires a reduced load command, judge the locking situation of M2.

2. The CCS instruction blocking load adjustment method based on the primary frequency modulation effect according to claim 1, wherein: The said step 3 includes Step S31: If the deviation between all high-pressure governor commands and feedback is < 1%, then consider the Y interval as valid data and proceed to the next step; Otherwise, consider the Y interval as invalid data and do not proceed to the calculation.

3. The CCS instruction locking load adjustment method based on the primary frequency regulation effect according to claim 1, wherein: The said step 4 includes Step S41: When the actual fluctuation range of the main steam pressure within the first 10 s before the moment of primary frequency modulation calculation is less than the fluctuation range corresponding to the unit capacity, it indicates that the boiler load and the turbine power are dynamically matched at this time. Then, it is considered that the Y interval calculated at this time is valid data, and proceed to the next step; Otherwise, it is considered that the Y interval is invalid data and does not enter the calculation.

4. The CCS instruction blocking load adjustment method based on the primary frequency regulation effect according to claim 1, wherein: The said step 5 includes Step S51: If before the moment of primary frequency modulation calculation, the AGC command remains stable for a time ≥ 10 minutes under the state where the AGC command change rate < 1%Pe / min, then the Y interval is valid data, and proceed to the next step; Otherwise, it is considered that the Y interval is invalid data and does not enter the calculation.

5. The CCS instruction locking load adjustment method based on the primary frequency regulation effect according to claim 1, characterized in that: The said step S7 includes Step S71: When M < Z, keep the turbine master command M2 changing with the AGC command; Step S72: When M ≥ Z, the turbine master command M2 is locked and does not move.

6. The CCS instruction locking load adjustment method based on the primary frequency regulation effect according to claim 1, wherein: The said step S8 includes Step S81: When M ≥ Z, keep the turbine master command changing with the AGC command; Step S82: When M < Z, the turbine master command is locked and does not move.

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