A feedforward compensation instruction adjustment method based on primary frequency modulation effect

Abstract

The present invention discloses a feedforward compensation instruction adjustment method based on the primary frequency modulation effect, comprising the following steps: adjusting the feedforward compensation instruction through an adjustment system; calculating the primary frequency modulation feedforward change value; judging whether all high-adjustment instructions and feedback deviations of the currently operating unit are less than 1%; if the actual fluctuation range of the main steam pressure is less than the fluctuation range of the corresponding unit capacity, the calculated new △Y interval is considered to be valid data; judging whether the AGC instruction stability time meets the requirements; each curve corresponds to a unique △Y interval; obtaining n different interval values ​​in the comprehensive valve position flow section Ri; calculating the △Y3 value; the original feedforward Y value is superimposed by the △Y3 value to form a new Y value; generating the primary frequency modulation power instruction value of the turbine throttle. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect of the present invention can provide auxiliary data support for the primary frequency modulation optimization adjustment without 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 feedforward compensation instruction 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 research direction of optimizing primary frequency regulation performance in China focuses on using DCS real-time data most of the time to analyze whether the amplitude of primary frequency regulation action and the action integral power in the corresponding time period meet the requirements of the power grid assessment standards, and calculate the dynamic compensation coefficient of primary frequency regulation. It does not attach importance to the guiding role of big data statistics of primary frequency regulation effect performance indicators in the analysis of primary frequency regulation characteristics, and fails to effectively mine DX data for frequency difference load command compensation optimization.

[0008] Based on the above situation, the present invention proposes a feedforward compensation instruction adjustment method based on a primary frequency modulation effect, which can effectively solve the above problems. Summary of the invention

[0009] The purpose of the present invention is to provide a feedforward compensation instruction adjustment method based on the primary frequency modulation effect. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect of the present invention is easy to use and can provide auxiliary data support for primary frequency modulation optimization adjustment without affecting the safe and stable operation of the unit itself.

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

[0011] A method for adjusting a feedforward compensation instruction based on a primary frequency modulation effect comprises the following steps:

[0012] Step S1: adjusting the feedforward compensation command through the adjustment system, the adjustment system includes five parts: frequency modulation integral performance parameter compensation output module, high-adjustment command feedback shielding module, steam pressure deviation shielding module, AGC command fluctuation shielding module and comprehensive valve position flow segment recording module;

[0013] Step S2: During the duration time ti of the primary frequency modulation action of the i-th time, a certain thermal power unit calculates the primary frequency modulation feedforward change value according to the ratio value DX data value of the actual primary frequency modulation action integral △QsYi of the network source platform end and the theoretical integral △QjYi required by the network source system;

[0014] Step S3: Determine whether all high-profile instructions and feedback deviations of the currently operating unit are less than 1%;

[0015] Step S4: Determine whether the main steam pressure is stable from 10 seconds before the frequency modulation action to the moment of the frequency modulation action;

[0016] Step S5: In the AGC instruction fluctuation shielding module, determine whether the AGC instruction stability time meets the requirement;

[0017] Step S6: Comprehensively calculate the n different interval values ​​in the valve position flow section Ri to obtain the △Y3 value;

[0018] Step S7: The original feedforward Y value is superimposed with the △Y3 value to form a new Y value;

[0019] Step S8: The generator frequency or turbine speed signal greater than the frequency modulation dead zone value is converted into a frequency difference power command value through slip inequality, and the frequency difference power command value is added to the new Y value of the primary frequency modulation feedforward load command to generate a primary frequency modulation power command value to the turbine throttle.

[0020] The purpose of the present invention is to provide a feedforward compensation instruction adjustment method based on the primary frequency modulation effect. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect of the present invention is easy to use and can provide auxiliary data support for primary frequency modulation optimization adjustment without affecting the safe and stable operation of the unit itself.

[0021] Preferably, step S2 includes

[0022] Step S21: If DX < β%, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱> 0, wherein the positive and negative directions of △Y1 are the same as △QjYi. Note that at this time, the positive and negative directions of △Y1 are the same as △QjYi, that is, if △QjYi is positive, △Y1 is positive, and if △QjYi is negative, △Y1 is negative. β% is the qualified amount of primary frequency modulation action exempt from assessment;

[0023] Calculate the primary frequency modulation feedforward change value △Y2, so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are the same as △QjYi. Note that at this time, the positive and negative directions of △Y2 are the same as △QjYi. At this time, a △Y interval value is obtained, that is, ︱△Y1︱<︱△Y︱<︱△Y2︱;

[0024] Step S22: If DX>2, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱>0. Note that the positive and negative directions of △Y1 are opposite to those of △QjYi, that is, if △QjYi is positive, △Y1 is negative, and if △QjYi is negative, △Y1 is positive. β% is the qualified amount of primary frequency modulation action exempted from assessment.

[0025] Calculate the primary frequency modulation feedforward change value △Y2 so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are opposite to △QjYi. At this time, a △Y interval value is obtained, that is, ︱△Y2︱<︱△Y︱<︱△Y1︱.

[0026] Preferably, step S3 includes

[0027] Step S31: If all high-profile commands and feedback deviations are less than 1%, the new △Y interval is considered to be valid data and the next step is entered;

[0028] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0029] Preferably, step S4 includes

[0030] Step S41: when the actual fluctuation range of the main steam pressure is smaller than the fluctuation range of the corresponding unit capacity within 10 seconds before the instant of frequency modulation calculation, the boiler load and the turbine power are dynamically matched at this time, and the calculated new △Y interval is considered to be valid data, and the next step is entered;

[0031] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0032] Preferably, step S5 includes

[0033] Step S51: When the AGC instruction change rate is less than 1% Pe / min, the AGC instruction remains stable for ≥10 minutes, then the new △Y interval calculated at this time is valid data, and the process proceeds to the next step;

[0034] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0035] Preferably, step S6 includes

[0036] Step S61: according to the broken line points of the integrated valve position flow rate curve of the steam turbine unit, the △Y interval value is matched with the straight line between every two broken line points, that is, each curve corresponds to a unique △Y interval value;

[0037] Step S62: obtaining n different interval values ​​in the comprehensive valve position flow segment Ri within a period of time;

[0038] Step S63: The ratio of the △Y interval value covering the comprehensive valve position flow section Ri is preset as S, and the △Y3 value is calculated, and the △Y3 value can satisfy the △Y interval value range above the S ratio.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] The feedforward compensation instruction adjustment method based on the primary frequency modulation effect of the present invention is easy to use and can provide auxiliary data support for the primary frequency modulation optimization adjustment without affecting the safe and stable operation of the unit itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flowchart of the present invention when DX<β%;

[0042] Figure 2 This is a flowchart of the present invention when DX>2. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments. However, it should be understood that the drawings are only used for exemplary description and cannot be understood as a limitation on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual 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 relationship described in the drawings is only for exemplary description and cannot be understood as a limitation on this patent.

[0044] Embodiment 1:

[0045] like Figures 1 to 2 As shown, the present invention provides a feedforward compensation instruction adjustment method based on a primary frequency modulation effect, comprising the following steps:

[0046] Step S1: adjusting the feedforward compensation command through the adjustment system, the adjustment system includes five parts: frequency modulation integral performance parameter compensation output module, high-adjustment command feedback shielding module, steam pressure deviation shielding module, AGC command fluctuation shielding module and comprehensive valve position flow segment recording module;

[0047] Step S2: During the duration time ti of the primary frequency modulation action of the i-th time, a certain thermal power unit calculates the primary frequency modulation feedforward change value according to the ratio value DX data value of the actual primary frequency modulation action integral △QsYi of the network source platform end and the theoretical integral △QjYi required by the network source system;

[0048] Step S3: Determine whether all high-profile instructions and feedback deviations of the currently operating unit are less than 1%;

[0049] Step S4: Determine whether the main steam pressure is stable from 10 seconds before the frequency modulation action to the moment of the frequency modulation action;

[0050] Step S5: In the AGC instruction fluctuation shielding module, determine whether the AGC instruction stability time meets the requirement;

[0051] Step S6: Comprehensively calculate the n different interval values ​​in the valve position flow section Ri to obtain the △Y3 value;

[0052] Step S7: The original feedforward Y value is superimposed with the △Y3 value to form a new Y value;

[0053] Step S8: The generator frequency or turbine speed signal greater than the frequency modulation dead zone value is converted into a frequency difference power command value through slip inequality, and the frequency difference power command value is added to the new Y value of the primary frequency modulation feedforward load command to generate a primary frequency modulation power command value to the turbine throttle.

[0054] Furthermore, in another embodiment, step S2 includes

[0055] Step S21: If DX is less than β%, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱>0, wherein the positive and negative directions of △Y1 are the same as △QjYi, that is, if △QjYi is positive, △Y2 is positive, and if △QjYi is negative, △Y2 is negative, and β% is the primary frequency modulation action exemption qualification amount;

[0056] Calculate the primary frequency modulation feedforward change value △Y2 so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are the same as △QjYi, that is, if △QjYi is positive, △Y2 is positive, and if △QjYi is negative, △Y2 is negative. At this time, a △Y interval value is obtained, that is, ︱△Y1︱<︱△Y︱<︱△Y2︱;

[0057] Step S22: If DX>2, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱>0. Note that the positive and negative directions of △Y1 are opposite to those of △QjYi, that is, if △QjYi is positive, △Y1 is negative, and if △QjYi is negative, △Y1 is positive. β% is the qualified amount of primary frequency modulation action exempted from assessment.

[0058] Calculate the primary frequency modulation feedforward change value △Y2 so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are opposite to △QjYi, that is, if △QjYi is positive, △Y2 is negative, and if △QjYi is negative, △Y2 is positive. At this time, a △Y interval value is obtained, that is, ︱△Y2︱<︱△Y︱<︱△Y1︱.

[0059] Furthermore, in another embodiment, step S3 includes

[0060] Step S31: If all high-profile commands and feedback deviations are less than 1%, the new △Y interval is considered to be valid data and the next step is entered;

[0061] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0062] Furthermore, in another embodiment, step S4 includes

[0063] Step S41: when the actual fluctuation range of the main steam pressure is smaller than the fluctuation range of the corresponding unit capacity within 10 seconds before the instant of frequency modulation calculation, the boiler load and the turbine power are dynamically matched at this time, and the calculated new △Y interval is considered to be valid data, and the next step is entered;

[0064] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0065] Furthermore, in another embodiment, step S5 includes

[0066] Step S51: When the AGC instruction change rate is less than 1% Pe / min, the AGC instruction remains stable for ≥10 minutes, then the new △Y interval calculated at this time is valid data, and the process proceeds to the next step;

[0067] Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

[0068] According to Article 5.1 of DL / T 657-2015 "Acceptance Test Procedure for Analog Control Systems of Thermal Power Plants", the AGC command change rate is less than 1% Pe / min. According to Appendix 2 of the "Implementation Rules for Auxiliary Service Management of Grid-connected Power Plants in East China", if the AGC command remains stable for 10 minutes, the new interval △Y calculated at this time is used as valid data.

[0069] Furthermore, in another embodiment, step S6 includes

[0070] Step S61: according to the broken line points of the integrated valve position flow rate curve of the steam turbine unit, the △Y interval value is matched with the straight line between every two broken line points, that is, each curve corresponds to a unique △Y interval value;

[0071] Step S62: obtaining n different interval values ​​in the comprehensive valve position flow segment Ri within a period of time;

[0072] Step S63: The ratio of the △Y interval value covering the comprehensive valve position flow section Ri is preset as S, and the △Y3 value is calculated, and the △Y3 value can satisfy the △Y interval value range above the S ratio.

[0073] According to the description and drawings of the present invention, those skilled in the art can easily manufacture or use the feedforward compensation instruction adjustment method based on the primary frequency modulation effect of the present invention, and can produce the positive effects recorded in the present invention.

[0074] Unless otherwise specified, in the present invention, the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood in conjunction with the drawings and according to specific circumstances.

[0075] Unless otherwise clearly specified and limited, in the present invention, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A feedforward compensation instruction adjustment method based on a primary frequency modulation effect, characterized in that: The following steps are involved: Step S1: adjusting the feedforward compensation command through the adjustment system, the adjustment system includes five parts: frequency modulation integral performance parameter compensation output module, high-adjustment command feedback shielding module, steam pressure deviation shielding module, AGC command fluctuation shielding module and comprehensive valve position flow segment recording module; Step S2: During the duration time ti of the i-th primary frequency modulation action, a thermal power unit calculates the primary frequency modulation feedforward change value according to the ratio DX data value of the actual primary frequency modulation action integral △QsYi of the network source platform end and the theoretical integral △QjYi required by the network source system; Step S3: Determine whether all high-profile instructions and feedback deviations of the currently running unit are less than 1%; Step S4: Determine whether the main steam pressure is stable from 10 seconds before the frequency modulation action to the moment of the frequency modulation action; Step S5: In the AGC instruction fluctuation shielding module, determine whether the AGC instruction stability time meets the requirement; Step S6: Comprehensively calculate the n different interval values ​​in the valve position flow section Ri to obtain the △Y3 value; Step S7: The original feedforward Y value is superimposed with the △Y3 value to form a new Y value; Step S8: The generator frequency or turbine speed signal greater than the frequency modulation dead zone value is converted by slip inequality to obtain a frequency difference power command value, and the frequency difference power command value is added to the new Y value of the primary frequency modulation feedforward load command to generate a primary frequency modulation power command value to the turbine throttle; The step S2 includes Step S21: If DX is less than β%, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱>0, wherein the positive and negative direction of △Y1 is the same as △QjYi, that is, if △QjYi is positive, △Y1 is positive, and if △QjYi is negative, △Y1 is negative, and β% is the primary frequency modulation action exemption qualification amount; Calculate the primary frequency modulation feedforward change value △Y2 so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are the same as △QjYi, and a △Y interval value is obtained, that is, ︱△Y1︱<︱△Y︱<︱△Y2︱; Step S22: If DX>2, calculate the primary frequency modulation feedforward change value △Y1, so that ︱△QsYi+△Y1×ti︱-︱△QjYi︱>0. Note that the positive and negative directions of △Y1 are opposite to those of △QjYi, that is, if △QjYi is positive, △Y1 is negative, and if △QjYi is negative, △Y1 is positive. β% is the primary frequency modulation action exemption qualification amount. Calculate the primary frequency modulation feedforward change value △Y2 so that ︱△QsYi+△Y2×ti︱-︱2×△QjYi︱<0, where the positive and negative directions of △Y2 are opposite to those of △QjYi. At this time, a △Y interval value is obtained, i.e. ︱△Y2︱<︱△Y︱<︱△Y1︱; The step S6 includes Step S61: according to the broken line points of the integrated valve position flow rate curve of the steam turbine unit, the △Y value is matched with the straight line between every two broken line points, that is, each curve corresponds to a unique △Y interval value; Step S62: obtaining n different interval values ​​in the comprehensive valve position flow segment Ri within a period of time; Step S63: preset the ratio of the △Y interval value covering the valve position flow section Ri as S, calculate and obtain the △Y3 value, and the △Y3 value can satisfy the △Y interval value range above the S ratio.

2. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect according to claim 1 is characterized in that: The step S3 includes Step S31: If all high-profile commands and feedback deviations are less than 1%, the new △Y interval is considered to be valid data and the process proceeds to the next step; Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

3. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect according to claim 1, characterized in that: The step S4 includes Step S41: when the actual fluctuation range of the main steam pressure is smaller than the fluctuation range of the corresponding unit capacity within 10 seconds before the instant of frequency modulation calculation, the boiler load and the turbine power are dynamically matched at this time, and the calculated new △Y interval is considered to be valid data, and the next step is entered; Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

4. The feedforward compensation instruction adjustment method based on the primary frequency modulation effect according to claim 1, characterized in that: The step S5 includes Step S51: When the AGC command change rate is less than 1%Pe / min, the AGC command remains stable for ≥10 minutes, then the new △Y interval calculated at this time is valid data, and the next step is entered; Otherwise, the new △Y interval is considered invalid data and will not be included in the calculation.

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