Method and system for controlling primary frequency modulation contribution rate of thermal power generating unit based on power grid frequency change

Abstract

The invention discloses a method and a system for controlling a primary frequency modulation contribution rate of a thermal power generating unit based on power grid frequency change. The system comprises a first delay module, a first NOT module and a first AND module, the network frequency over-dead zone is sequentially connected with the first delay module and the first non-module, the output end of the first non-module and the network frequency over-dead zone are connected to the first AND module, and the output end of the first AND module is connected to the frequency modulation action. The method comprises the following steps: outputting a frequency modulation action signal when a network frequency over-dead-zone signal is 1 and is within 60 seconds; the network frequency and the reference deviation are corrected by the first function module to obtain a theoretical frequency modulation instruction signal; when the frequency modulation action is 1, judging a unit power signal and a power command signal to obtain a power variation signal and an initial deviation signal; and when the frequency modulation action is 1 and 9 seconds are delayed, the initial deviation signals are respectively corrected, and the theoretical frequency modulation instruction signals are respectively judged to obtain reverse modulation correction signals. According to the invention, the purpose of accurate matching meeting the theoretical requirements of power grid frequency change is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent control of thermal power plants, and specifically relates to a method and system for accurately controlling the primary frequency regulation contribution rate of a thermal power unit based on power grid frequency changes. Background Art

[0002] With the massive incorporation of new energy sources such as wind power and photovoltaics into the power grid in recent years, the effective contribution rate of primary frequency regulation provided by traditional thermal power units has become increasingly important for maintaining the stability of the power grid frequency. The regulations require that the ratio (effective contribution rate) of the actual contribution of primary frequency regulation of thermal power units to the theoretical contribution calculated by the grid frequency deviation should be within a certain range and should not be too low or too high, so as to eliminate the grid frequency oscillation or long-term fluctuation caused by unreasonable primary frequency regulation parameter settings of thermal power units after the grid frequency dead zone is eliminated. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for accurately controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes. The present invention adopts a feedforward + PID closed-loop control method to achieve rapid power changes of thermal power units after grid frequency changes, thereby achieving the purpose of accurate matching to meet the theoretical requirements of grid frequency changes.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A system for controlling the primary frequency regulation contribution rate of a thermal power unit based on a change in power grid frequency, comprising a first delay module, a first non-module and a first and module;

[0006] The network frequency dead zone is connected to the first delay module and the first non-module in sequence, the output end of the first non-module and the network frequency dead zone are both connected to the first and module, and the output end of the first and module is connected to the frequency modulation action.

[0007] A further improvement of the present invention is that it further comprises a first function module, the network frequency and the reference deviation are connected to the first function module, and the output end of the first function module is connected to the theoretical frequency modulation instruction.

[0008] A further improvement of the present invention is that it further comprises a dynamic averaging module, a first switching module, a second switching module, a third switching module, a first comparator module and a second comparator module;

[0009] The unit power is respectively connected to the dynamic average module, the N-end of the second switching module, the dynamic average module, and the first comparator module. The dynamic average module is connected to the N-end of the first switching module, the output end of the first switching module is connected to the Y-end of a switching module, and the frequency modulation action is connected to the trigger end of the first switching module; the output end of the first switching module is connected to the Y-end of the second switching module, and the frequency modulation action is connected to the trigger end of the second switching module; the output end of the second switching module is connected to the first comparator module, and the output end of the first comparator module is connected to the power change amount; the power instruction is connected to the N-end of the third switching module, the output end of the third switching module is connected to the Y-end of the third switching module, the frequency modulation action is connected to the trigger end of the frequency modulation action, the output end of the third switching module and the output end of the second switching module are both connected to the second comparator module, and the output end of the second comparator module is connected to the initial deviation.

[0010] A further improvement of the present invention is that it further includes a second function module, a third function module, a first greater than module, a first less than module, a second delay module, a fourth switching module, a fifth switching module, a sixth switching module and a first constant 0 module;

[0011] The first constant 0 module is respectively connected to the N-end of the fourth switching module and the N-end of the sixth switching module, the initial deviation is respectively connected to the second function module and the third function module, the theoretical frequency modulation instruction is connected to the first greater than module, the output end of the first greater than module is connected to the trigger end of the fourth switching module, and the output end of the second function module is connected to the Y-end of the fourth switching module; the output end of the fourth switching module is connected to the N-end of the fifth switching module, the output end of the third function module is connected to the Y-end of the fifth switching module, the theoretical frequency modulation instruction is connected to the trigger end of the first less than module and the fifth switching module in sequence; the output end of the fifth switching module is connected to the Y-end of the sixth switching module, and the frequency modulation action is connected to the trigger end of the second delay module and the sixth switching module in sequence; the output end of the sixth switching module is connected to the anti-modulation correction.

[0012] A further improvement of the present invention is that it also includes a second constant 0 module, a third constant 0 module, a seventh switching module, a first adding module, an eighth switching module, a first dividing module, a first constant 1 module, a ninth switching module, a tenth switching module, a second adding module, an eleventh switching module and a third delay module;

[0013] The second constant 0 module is connected to the N end of the seventh switching module and the N end of the eighth switching module respectively, the power change amount is connected to the Y end of the seventh switching module, and the frequency modulation action is connected to the trigger end of the third delay module and the seventh switching module in sequence; the output end of the eighth switching module and the output end of the seventh switching module are both connected to the first adding module, and the output end of the first adding module is connected to the Y end of the eighth switching module; the output end of the third delay module is connected to the trigger end of the tenth switching module and the trigger end of the ninth switching module respectively, the third constant 0 module is connected to the N end of the tenth switching module and the N end of the eleventh switching module respectively, and the theoretical frequency modulation instruction is connected to the Y end of the tenth switching module; the output end of the tenth switching module and the output end of the eleventh switching module are both connected to the second adding module, and the output end of the second adding module is connected to the Y end of the eleventh switching module; the output end of the eleventh switching module is connected to the Y end of the ninth switching module, and the first constant 1 module is connected to the trigger end of the ninth switching module; the output end of the eighth switching module and the output end of the ninth switching module are both connected to the first dividing module, and the output end of the first dividing module is connected to the quality.

[0014] A further improvement of the present invention is that it also includes a fourth constant 0 module, a fourth function module, a fifth function module, a first PID module, a second PID module, a twelfth switching module, a thirteenth switching module, a fourteenth switching module, a second greater than module, a second less than module and a fourth delay module

[0015] The fourth constant 0 module is respectively connected to the N end of the twelfth switching module and the N end of the fourteenth switching module, the quality is sequentially connected to the fourth function module, the first PID module, and the Y end of the twelfth switching module, and the theoretical frequency modulation instruction is sequentially connected to the second greater than module and the trigger end of the twelfth switching module; the twelfth switching module is connected to the N end of the thirteenth switching module, the quality is sequentially connected to the fifth function module, the second PID module, and the Y end of the thirteenth switching module; the thirteenth switching module is connected to the Y end of the fourteenth switching module, and the frequency modulation action is sequentially connected to the fourth delay module and the trigger end of the fourteenth switching module; the output end of the fourteenth switching module is connected to the quality correction.

[0016] A further improvement of the present invention is that it also includes a third adding module; the theoretical frequency modulation instruction, the reverse modulation correction and the quality correction are all connected to the third adding module, and the output end of the third adding module corrects the frequency modulation instruction.

[0017] A method for controlling the primary frequency regulation contribution rate of a thermal power unit based on a change in power grid frequency, the method is based on the system for controlling the primary frequency regulation contribution rate of a thermal power unit based on a change in power grid frequency, and comprises:

[0018] When the network frequency dead zone signal is 1 and meets the requirement of 60 seconds, the frequency modulation action signal is output;

[0019] The network frequency and the reference deviation are corrected by the first function module to obtain a theoretical frequency modulation command signal;

[0020] When the frequency modulation action is 1, the power signal and the power command signal of the unit are judged by the dynamic average module, the first switching module, the second switching module, the third switching module, the first comparator module, and the second comparator module respectively, and the power change signal and the initial deviation signal are obtained;

[0021] When the frequency modulation action is 1 and the delay is 9 seconds, the initial deviation signal is corrected by the second function module and the third function module respectively, and the theoretical frequency modulation command signal is judged by the first greater than module and the first less than module respectively, and finally after the judgment of the fourth switching module, the fifth switching module and the sixth switching module, the anti-modulation correction signal is obtained.

[0022] A further improvement of the present invention is that, when the frequency modulation action is 1 and the delay is 0.5 seconds, the power change amount passes through the seventh switching module, the first adding module, and the eighth switching module respectively, and the theoretical frequency modulation instruction passes through the tenth switching module, the second adding module, the eleventh switching module, and the ninth switching module respectively. The calculated power variable output by the eighth switching module and the calculated theoretical frequency modulation instruction output by the ninth switching module are divided by the first division module to finally obtain the quality.

[0023] A further improvement of the present invention is that when the frequency modulation action is 1 and the delay is 9 seconds, and the theoretical frequency modulation instruction satisfies the function setting greater than 0.5 in the second greater than module; the quality signal passes through the second greater than module, the first PID module, and the twelfth switching module in sequence, and the quality signal passes through the fifth function module, the second PID module, and the thirteenth switching module in sequence; finally, after calculation by the fourteenth switching module, the quality correction is obtained;

[0024] The theoretical frequency modulation command signal, the anti-modulation correction signal and the quality correction signal are all added together by the third adding module to finally obtain the corrected frequency modulation command.

[0025] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0026] The method and system for accurately controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes provided by the present invention adopt a feedforward + PID closed-loop control method to achieve rapid power changes of thermal power units after grid frequency changes, thereby achieving the purpose of accurate matching to meet the theoretical requirements of grid frequency changes.

[0027] The present invention provides a method and system for accurately controlling the primary frequency modulation contribution rate of a thermal power unit based on the change of the power grid frequency. After the power grid frequency changes out of the dead zone, the present invention locks the current actual power and calculates the actual integral power according to the deviation between the actual power and the locked current actual power. Then, according to the ratio of the theoretical integral power calculated by the change of the power grid frequency, the primary frequency modulation contribution rate of the unit is calculated in real time, and according to the preset contribution rate interval, the primary frequency modulation load instruction of the unit is dynamically adjusted, so as to achieve the effective contribution rate interval in which the actual power integral power of the unit meets the requirements of the power grid.

[0028] In summary, the method and system for accurately controlling the primary frequency regulation contribution rate of a thermal power unit based on grid frequency changes described in the present invention take into account the safety, stability and efficiency of the unit under different operating conditions, and play an important role in improving the operating reliability and economy of the entire unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figures 1 to 7 They are the control principle diagrams of the system for accurately controlling the primary frequency regulation contribution rate of thermal power units based on changes in grid frequency.

[0030] Figure 8 It is a rendering of the effect in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0032] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0033] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0034] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0035] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0036] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] A control strategy is designed to accurately control the primary frequency regulation contribution rate of thermal power units based on grid frequency changes. The feedforward + PID closed-loop control method is adopted to achieve rapid power changes of thermal power units after grid frequency changes, so as to achieve the purpose of accurate matching to meet the theoretical requirements of grid frequency changes.

[0039] Figures 1 to 7 They are respectively the control principle diagrams for accurately controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes.

[0040] It specifically includes: network frequency dead zone 001, network frequency and reference deviation 002, unit power 003, frequency modulation action 004, power instruction 005, initial deviation 006, theoretical frequency modulation instruction 007, power change 008, quality 009, reverse modulation correction 010, quality correction 011, corrected frequency modulation instruction 012, first delay module 013, first non-module 014, first and module 015, first function module 016, dynamic average module 017, first switching module 018, second switching module 019, third switching module 020, first comparator module 021, second comparator module 022, second function module 023, third function module 024, first greater than module 025, first less than module 026, second delay module 027, fourth switching module 028, fifth switching module Block 029, sixth switching module 030, first constant 0 module 031, second constant 0 module 032, third constant 0 module 033, fourth constant 0 module 034, seventh switching module 035, first addition module 036, eighth switching module 037, first division module 038, first constant 1 module 039, ninth switching module 040, tenth switching module 041, second addition module 042, eleventh switching module 043, third delay module 044, fourth function module 045, fifth function module 046, first PID module 047, second PID module 048, twelfth switching module 049, thirteenth switching module 050, fourteenth switching module 051, second greater than module 052, second less than module 053, fourth delay module 054, third addition module 055.

[0041] Figures 1 to 4 The control strategy logic diagram contains:

[0042] The network frequency dead zone 001 is connected to the first delay module 013 and the first non-module 014 in sequence, the output end of the first non-module 014 and the network frequency dead zone 001 are both connected to the first AND module 015, and the output end of the first AND module 015 is connected to the frequency modulation action 004.

[0043] The grid frequency and reference deviation 002 are connected to the first function module 016 , and the output end of the first function module 016 is connected to the theoretical frequency modulation instruction 007 .

[0044] The unit power 003 is respectively connected to the dynamic average module 017, the N end of the second switching module 019, the dynamic average module 017, and the first comparator module 021. The dynamic average module 017 is connected to the N end of the first switching module 018. The output end of the first switching module 018 is connected to the Y end of the first switching module 018. The frequency modulation action 004 is connected to the trigger end of the first switching module 018; the output end of the first switching module 018 is connected to the Y end of the second switching module 019, and the frequency modulation action 004 is connected to the trigger end of the second switching module 019; the second switching The output end of module 019 is connected to the first comparator module 021, and the output end of the first comparator module 021 is connected to the power change 008; the power instruction 005 is connected to the N end of the third switching module 020, and the output end of the third switching module 020 is connected to the Y end of the third switching module 020, the frequency modulation action 004 is connected to the trigger end of the frequency modulation action 004, and the output end of the third switching module 020 and the output end of the second switching module 019 are both connected to the second comparator module 022, and the output end of the second comparator module 022 is connected to the initial deviation 006.

[0045] The first constant 0 module 031 is respectively connected to the N end of the fourth switching module 028 and the N end of the sixth switching module 030, the initial deviation 006 is respectively connected to the second function module 023 and the third function module 024, the theoretical frequency modulation instruction 007 is connected to the first greater than module 025, the output end of the first greater than module 025 is connected to the trigger end of the fourth switching module 028, the output end of the second function module 023 is connected to the Y end of the fourth switching module 028; the output end of the fourth switching module 028 is connected to the N end of the fifth switching module 029, the output end of the third function module 024 is connected to the Y end of the fifth switching module 029, the theoretical frequency modulation instruction 007 is connected to the trigger ends of the first less than module 026 and the fifth switching module 029 in sequence; the output end of the fifth switching module 029 is connected to the Y end of the sixth switching module 030, the frequency modulation action 004 is connected to the trigger ends of the second delay module 027 and the sixth switching module 030 in sequence; the output end of the sixth switching module 030 is connected to the anti-modulation correction 010.

[0046] Figures 5 to 7 The control strategy logic diagram contains:

[0047] The second constant 0 module 032 is connected to the N end of the seventh switching module 035 and the N end of the eighth switching module 037 respectively, the power change amount 008 is connected to the Y end of the seventh switching module 035, and the frequency modulation action 004 is connected to the third delay module 044 and the trigger end of the seventh switching module 035 in sequence; the output end of the eighth switching module 037 and the output end of the seventh switching module 035 are both connected to the first adding module 036, and the output end of the first adding module 036 is connected to the Y end of the eighth switching module 037; the output end of the third delay module 044 is connected to the trigger end of the tenth switching module 041 and the trigger end of the ninth switching module 040 respectively, and the third constant 0 module 033 is connected to the trigger end of the tenth switching module 041 and the trigger end of the ninth switching module 040 respectively. 041, the N end of the eleventh switching module 043, and the theoretical frequency modulation instruction 007 is connected to the Y end of the tenth switching module 041; the output end of the tenth switching module 041 and the output end of the eleventh switching module 043 are both connected to the second adding module 042, and the output end of the second adding module 042 is connected to the Y end of the eleventh switching module 043; the output end of the eleventh switching module 043 is connected to the Y end of the ninth switching module 040, and the first constant 1 module 039 is connected to the trigger end of the ninth switching module 040; the output end of the eighth switching module 037 and the output end of the ninth switching module 040 are both connected to the first division module 038, and the output end of the first division module 038 is connected to the quality 009.

[0048] The fourth constant 0 module 034 is respectively connected to the N end of the twelfth switching module 049 and the N end of the fourteenth switching module 051, the quality 009 is sequentially connected to the fourth function module 045, the first PID module 047, and the Y end of the twelfth switching module 049, and the theoretical frequency modulation instruction 007 is sequentially connected to the second greater than module 052 and the trigger end of the twelfth switching module 049; the twelfth switching module 049 is connected to the N end of the thirteenth switching module 050, the quality 009 is sequentially connected to the fifth function module 046, the second PID module 048, and the Y end of the thirteenth switching module 050; the thirteenth switching module 050 is connected to the Y end of the fourteenth switching module 051, and the frequency modulation action 004 is sequentially connected to the fourth delay module 054 and the trigger end of the fourteenth switching module 051; the output end of the fourteenth switching module 051 is connected to the quality correction 011.

[0049] The theoretical frequency modulation instruction 007 , the anti-modulation correction 010 , and the quality correction 011 are all connected to the third adding module 055 , and the output end of the third adding module 055 corrects the frequency modulation instruction 012 .

[0050] Example 2

[0051] The method for controlling the primary frequency regulation contribution rate of a thermal power unit based on a change in power grid frequency provided by the present invention comprises:

[0052] Figures 1 to 4 The control modes are:

[0053] 1) When the network frequency passes the dead zone 001 signal and is 1 and meets the requirement of 60 seconds, the frequency modulation action 004 signal is output;

[0054] 2) The network frequency and the reference deviation 002 are corrected by the first function module 016 to obtain the theoretical frequency modulation instruction 007 signal;

[0055] 3) When the frequency modulation action 004 is 1, the unit power 003 signal and the power command 005 signal are respectively judged by the dynamic average module 017, the first switching module 018, the second switching module 019, the third switching module 020, the first comparator module 021, and the second comparator module 022 to obtain the power change 008 signal and the initial deviation 006 signal;

[0056] 4) When the frequency modulation action 004 is 1 and the delay is 9 seconds, the initial deviation 006 signal is corrected by the second function module 023 and the third function module 024 respectively, and the theoretical frequency modulation instruction 007 signal is judged by the first greater than module 025 and the first less than module 026 respectively, and finally after the judgment of the fourth switching module 028, the fifth switching module 029 and the sixth switching module 030, the reverse modulation correction 010 signal is obtained.

[0057] Figures 5 to 7 The control modes are:

[0058] 1) When the frequency modulation action 004 is 1 and the delay is 0.5 seconds, the power change 008 passes through the seventh switching module 035, the first adding module 036, and the eighth switching module 037 respectively, and the theoretical frequency modulation instruction 007 passes through the tenth switching module 041, the second adding module 042, the eleventh switching module 043, and the ninth switching module 040 respectively. The calculated power variable output by the eighth switching module 037 and the calculated theoretical frequency modulation instruction output by the ninth switching module 040 are divided by the first dividing module 038, and finally the quality 009 is obtained.

[0059] 2) When the frequency modulation action 004 is 1 and the delay is 9 seconds, and the theoretical frequency modulation instruction 007 satisfies the function setting greater than 0.5 in the second greater than module 052; then the quality 009 signal passes through the second greater than module 052, the first PID module 047, and the twelfth switching module 049 in sequence, and at the same time, the quality 009 signal passes through the fifth function module 046, the second PID module 048, and the thirteenth switching module 050 in sequence; finally, after calculation by the fourteenth switching module 051, the quality correction 011 is obtained.

[0060] 3) The theoretical frequency modulation instruction 007 signal, the anti-modulation correction 010 signal, and the quality correction 011 signal are all added together by the third adding module 055 to finally obtain the corrected frequency modulation instruction 012.

[0061] Example 3

[0062] After the implementation and application of the technology of the present invention, the primary frequency regulation curve is shown in the figure below, where 1 is load instruction 1; 2 is generator power; 3 is frequency regulation instruction; 4 is real-time frequency regulation response quality; 5 is primary frequency regulation action, and the unit power continuously sends changes to meet the precise matching purpose of the theoretical requirements of power grid frequency changes, thereby achieving precise control of primary frequency regulation.

[0063] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0064] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes, characterized in that: It includes a first delay module (013), a first negation module (014) and a first and module (015); The network frequency dead zone (001) is connected to the first delay module (013) and the first non-module (014) in sequence, the output end of the first non-module (014) and the network frequency dead zone (001) are both connected to the first AND module (015), and the output end of the first AND module (015) is connected to the frequency modulation action (004).

2. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 1 is characterized in that: It also includes a first function module (016), the network frequency and the reference deviation (002) are connected to the first function module (016), and the output end of the first function module (016) is connected to the theoretical frequency modulation instruction (007).

3. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 2 is characterized in that: It also includes a dynamic averaging module (017), a first switching module (018), a second switching module (019), a third switching module (020), a first comparator module (021) and a second comparator module (022); The unit power (003) is respectively connected to the dynamic average module (017), the N end of the second switching module (019), the dynamic average module (017), and the first comparator module (021); the dynamic average module (017) is connected to the N end of the first switching module (018); the output end of the first switching module (018) is connected to the Y end of a switching module (018); the frequency modulation action (004) is connected to the trigger end of the first switching module (018); the output end of the first switching module (018) is connected to the Y end of the second switching module (019); the frequency modulation action (004) is connected to the trigger end of the second switching module (019); the second switching The output end of the module (019) is connected to the first comparator module (021), and the output end of the first comparator module (021) is connected to the power change amount (008); the power instruction (005) is connected to the N end of the third switching module (020), the output end of the third switching module (020) is connected to the Y end of the third switching module (020), the frequency modulation action (004) is connected to the trigger end of the frequency modulation action (004), the output end of the third switching module (020) and the output end of the second switching module (019) are both connected to the second comparator module (022), and the output end of the second comparator module (022) is connected to the initial deviation (006).

4. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 3 is characterized in that: It also includes a second function module (023), a third function module (024), a first greater than module (025), a first less than module (026), a second delay module (027), a fourth switching module (028), a fifth switching module (029), a sixth switching module (030) and a first constant 0 module (031); The first constant 0 module (031) is respectively connected to the N terminal of the fourth switching module (028) and the N terminal of the sixth switching module (030), the initial deviation (006) is respectively connected to the second function module (023) and the third function module (024), the theoretical frequency modulation instruction (007) is connected to the first greater than module (025), the output end of the first greater than module (025) is connected to the trigger end of the fourth switching module (028), the output end of the second function module (023) is connected to the Y terminal of the fourth switching module (028); the output end of the fourth switching module (028) is connected To the N end of the fifth switching module (029), the output end of the third function module (024) is connected to the Y end of the fifth switching module (029), the theoretical frequency modulation instruction (007) is connected to the trigger end of the first less than module (026) and the fifth switching module (029) in sequence; the output end of the fifth switching module (029) is connected to the Y end of the sixth switching module (030), the frequency modulation action (004) is connected to the trigger end of the second delay module (027) and the sixth switching module (030) in sequence; the output end of the sixth switching module (030) is connected to the anti-modulation correction (010).

5. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 4 is characterized in that: It also includes a second constant 0 module (032), a third constant 0 module (033), a seventh switching module (035), a first adding module (036), an eighth switching module (037), a first dividing module (038), a first constant 1 module (039), a ninth switching module (040), a tenth switching module (041), a second adding module (042), an eleventh switching module (043) and a third delay module (044); The second constant 0 module (032) is respectively connected to the N end of the seventh switching module (035) and the N end of the eighth switching module (037); the power change amount (008) is connected to the Y end of the seventh switching module (035); the frequency modulation action (004) is sequentially connected to the third delay module (044) and the trigger end of the seventh switching module (035); the output end of the eighth switching module (037) and the output end of the seventh switching module (035) are both connected to the first adding module (036); the output end of the first adding module (036) is connected to the Y end of the eighth switching module (037); the output end of the third delay module (044) is respectively connected to the trigger end of the tenth switching module (041) and the trigger end of the ninth switching module (040); the third constant 0 module (033) is respectively connected to the trigger end of the tenth switching module (041); and the output end of the third delay module (044) is respectively connected to the trigger end of the ninth switching module (040). The output end of the tenth switching module (041) and the output end of the eleventh switching module (043) are connected to the N end of the ninth switching module (040), and the N end of the eleventh switching module (041), and the theoretical frequency modulation instruction (007) is connected to the Y end of the tenth switching module (041); the output end of the tenth switching module (041) and the output end of the eleventh switching module (043) are both connected to the second adding module (042), and the output end of the second adding module (042) is connected to the Y end of the eleventh switching module (043); the output end of the eleventh switching module (043) is connected to the Y end of the ninth switching module (040), and the first constant 1 module (039) is connected to the trigger end of the ninth switching module (040); the output end of the eighth switching module (037) and the output end of the ninth switching module (040) are both connected to the first dividing module (038), and the output end of the first dividing module (038) is connected to the quality (009).

6. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 5 is characterized in that: The method further comprises a fourth constant 0 module (034), a fourth function module (045), a fifth function module (046), a first PID module (047), a second PID module (048), a twelfth switching module (049), a thirteenth switching module (050), a fourteenth switching module (051), a second greater than module (052), a second less than module (053) and a fourth delay module (054). The fourth constant 0 module (034) is respectively connected to the N end of the twelfth switching module (049) and the N end of the fourteenth switching module (051); the quality (009) is sequentially connected to the fourth function module (045), the first PID module (047), and the Y end of the twelfth switching module (049); the theoretical frequency modulation instruction (007) is sequentially connected to the second greater than module (052) and the trigger end of the twelfth switching module (049); the twelfth switching module (049) is connected to the N end of the thirteenth switching module (050); the quality (009) is sequentially connected to the fifth function module (046), the second PID module (048), and the Y end of the thirteenth switching module (050); the thirteenth switching module (050) is connected to the Y end of the fourteenth switching module (051); the frequency modulation action (004) is sequentially connected to the fourth delay module (054) and the trigger end of the fourteenth switching module (051); the output end of the fourteenth switching module (051) is connected to the quality correction (011).

7. The system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes according to claim 6 is characterized in that: It also includes a third adding module (055); the theoretical frequency modulation instruction (007), the reverse modulation correction (010) and the quality correction (011) are all connected to the third adding module (055), and the output end of the third adding module (055) corrects the frequency modulation instruction (012).

8. A method for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes, characterized in that: The method is based on the system for controlling the primary frequency regulation contribution rate of thermal power units based on grid frequency changes as described in claim 7, and comprises: When the network frequency passes the dead zone (001) signal is 1 and is within 60 seconds, the frequency modulation action (004) signal is output; The network frequency and the reference deviation (002) are corrected by the first function module (016) to obtain a theoretical frequency modulation instruction (007) signal; When the frequency modulation action (004) is 1, the unit power (003) signal and the power command (005) signal are respectively judged by the dynamic average module (017), the first switching module (018), the second switching module (019), the third switching module (020), the first comparator module (021), and the second comparator module (022), thereby obtaining a power change (008) signal and an initial deviation (006) signal; When the frequency modulation action (004) is 1 and the delay is 9 seconds, the initial deviation (006) signal is corrected by the second function module (023) and the third function module (024), respectively, and the theoretical frequency modulation instruction (007) signal is judged by the first greater than module (025) and the first less than module (026), respectively, and finally after the judgment of the fourth switching module (028), the fifth switching module (029) and the sixth switching module (030), the reverse modulation correction (010) signal is obtained.

9. The method for controlling the primary frequency regulation contribution rate of a thermal power unit based on grid frequency change according to claim 8, characterized in that: When the frequency modulation action (004) is 1 and the delay is 0.5 seconds, the power change (008) passes through the seventh switching module (035), the first adding module (036), and the eighth switching module (037) respectively, and the theoretical frequency modulation instruction (007) passes through the tenth switching module (041), the second adding module (042), the eleventh switching module (043), and the ninth switching module (040) respectively. The calculated power variable output by the eighth switching module (037) and the calculated theoretical frequency modulation instruction output by the ninth switching module (040) are divided by the first dividing module (038), and finally the quality (009) is obtained.

10. The method for controlling the primary frequency regulation contribution rate of a thermal power unit based on grid frequency change according to claim 9, characterized in that: When the frequency modulation action (004) is 1 and the delay is 9 seconds, and the theoretical frequency modulation instruction (007) satisfies the function setting greater than 0.5 in the second greater than module (052); the quality (009) signal passes through the second greater than module (052), the first PID module (047), and the twelfth switching module (049) in sequence, and the quality (009) signal passes through the fifth function module (046), the second PID module (048), and the thirteenth switching module (050) in sequence; finally, after calculation by the fourteenth switching module (051), the quality correction (011) is obtained; The theoretical frequency modulation instruction (007) signal, the reverse modulation correction (010) signal, and the quality correction (011) signal are all added together by the third adding module (055) to finally obtain the corrected frequency modulation instruction (012).

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