A primary frequency control system and method

Abstract

The application discloses a kind of primary frequency control system and method.The system includes: first power limiting module, for determining the first adjustment value according to the current power of generator set and first power limit value, determining the second adjustment value according to current power and second power limit value, the intermediate value in power adjustment value, first adjustment value and second adjustment value is third adjustment value;Second power limiting module, for determining the fourth adjustment value according to the current thermal power of reactor, the smaller value in third adjustment value and fourth adjustment value is fifth adjustment value;Third power limiting module, for determining the sixth adjustment value according to current thermal power and third power limit value, determining the seventh adjustment value according to current thermal power and fourth power limit value, the intermediate value in fifth adjustment value, sixth adjustment value and seventh adjustment value is eighth adjustment value;First switching module, for outputting eighth adjustment value.The technical scheme of the application improves the safety of reactor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of primary frequency modulation, and in particular to a primary frequency modulation control system and method. BACKGROUND

[0002] Primary frequency modulation refers to a control function that when the frequency of a power system deviates from a target frequency, a steam turbine generator set adjusts the output power of the generator set through the automatic reaction of a control system to reduce the frequency deviation.

[0003] When a nuclear power generator set uses primary frequency modulation to adjust the output power of the generator set, the frequency adjustment value contained in the primary frequency modulation instruction added or subtracted from the original power may cause the power of the generator set to be too large or too small, thereby causing the thermal power of the nuclear reactor to be too large (for example, exceeding 100% of the rated power) or too small, and further reducing the safety margin of the reactor, so that the safety risk of the generator set is large. SUMMARY

[0004] The present application provides a primary frequency modulation control system and method to solve the problem of causing the thermal power of the reactor to be too large or too small and causing safety risks during primary frequency modulation.

[0005] According to an aspect of the present application, a primary frequency modulation control system is provided, which comprises:

[0006] A first power limiting module is configured to determine a first adjustment value according to the current power of the generator set and a first power limit value, determine a second adjustment value according to the current power and a second power limit value, and determine a third adjustment value as the intermediate value of the primary adjustment power adjustment value, the first adjustment value and the second adjustment value.

[0007] A second power limiting module is connected to the first power limiting module and is configured to determine a fourth adjustment value according to the current thermal power of the reactor and a first preset relationship, and determine a fifth adjustment value as the smaller value of the third adjustment value and the fourth adjustment value.

[0008] A third power limiting module is connected to the second power limiting module and is configured to determine a sixth adjustment value according to the current thermal power and a third power limit value, determine a seventh adjustment value according to the current thermal power and a fourth power limit value, and determine an eighth adjustment value as the intermediate value of the fifth adjustment value, the sixth adjustment value and the seventh adjustment value.

[0009] A first switching module is connected to the third power limiting module and is configured to output the eighth adjustment value to a primary frequency modulation system when the current thermal power is within a preset range, so that the primary frequency modulation system adjusts the output power of the generator set according to the eighth adjustment value.

[0010] Optionally, the first power limiting module comprises:

[0011] a first high selection unit, connected to the first power limit value and the current power, and configured to output a first larger value between the first power limit value and the current power;

[0012] a first calculation unit, connected to the first high selection unit and connected to the first power limit value, and configured to calculate a first difference between the first power limit value and the first larger value, and take the first difference as the first adjustment value;

[0013] a second high selection unit, connected to the first calculation unit and connected to the power adjustment value, and configured to output a second larger value between the first adjustment value and the power adjustment value;

[0014] a first low selection unit, connected to the second power limit value and the current power, and configured to output a first smaller value between the second power limit value and the current power;

[0015] a second calculation unit, connected to the second power limit value and connected to the first low selection unit, and configured to calculate a second difference between the second power limit value and the first smaller value, and take the second difference as the second adjustment value;

[0016] a second low selection unit, connected to the second high selection unit and the second calculation unit respectively, and configured to output a third adjustment value which is a smaller value between the second larger value and the second adjustment value.

[0017] Optionally, the second power limiting module comprises:

[0018] a third calculation unit, connected to the current thermal power, and configured to determine the fourth adjustment value according to the first preset relationship between the current thermal power and the first preset relationship;

[0019] a third low selection unit, connected to the third adjustment value and connected to the third calculation unit, and configured to output a fifth adjustment value which is a smaller value between the third adjustment value and the fourth adjustment value.

[0020] Optionally, the third power limiting module comprises:

[0021] a third high selection unit, connected to the third power limit value and the current thermal power, and configured to output a third larger value between the third power limit value and the current thermal power;

[0022] a fourth calculation unit, connected to the third high selection unit and connected to the third power limit value, and configured to calculate a third difference between the third power limit value and the third larger value, and take the third difference as the sixth adjustment value;

[0023] a fourth high selection unit, connected with the fourth calculation unit and accessing the fifth adjustment value, configured to output a fourth larger value between the fifth adjustment value and the sixth adjustment value;

[0024] a fourth low selection unit, accessing the fourth power limit value and the current thermal power, configured to output a third smaller value between the fourth power limit value and the current thermal power;

[0025] a fifth calculation unit, accessing the fourth power limit value and connected with the fourth low selection unit, configured to calculate a fourth difference value between the fourth power limit value and the third smaller value, and output the fourth difference value as a seventh adjustment value;

[0026] a fifth low selection unit, connected with the fourth high selection unit and the fifth calculation unit respectively, configured to output a smaller value between the fourth larger value and the seventh adjustment value as an eighth adjustment value.

[0027] Optionally, the primary frequency control system further comprises:

[0028] a second switching module, accessing a frequency deviation value, configured to output the frequency deviation value when the current power is greater than or equal to the first power limit value; wherein the frequency deviation value is a difference between a primary frequency of the power grid and a target frequency;

[0029] a primary adjustment module, connected with the second switching module, configured to determine the power adjustment value according to the frequency deviation value and a second preset relationship.

[0030] Optionally, the primary frequency control system further comprises: a first enabling module, accessing the current power and the first power limit value, configured to enable the second switching module when the current power is greater than or equal to the first power limit value.

[0031] Optionally, the primary frequency control system further comprises: a second enabling module, accessing the current thermal power, the third power limit value and the fourth power limit value, configured to enable the first switching module when the current thermal power is greater than or equal to the third power limit value and less than or equal to the fourth power limit value.

[0032] According to another aspect of the present application, a primary frequency control method is provided, the primary frequency control method comprising:

[0033] determining a first adjustment value according to a current power of the generator set and a first power limit value, determining a second adjustment value according to the current power and a second power limit value, and outputting a middle value between the primary adjustment power adjustment value, the first adjustment value and the second adjustment value as a third adjustment value;

[0034] determine a fourth adjustment value according to the current thermal power of the reactor and a first preset relationship, and take the smaller one of the third adjustment value and the fourth adjustment value as a fifth adjustment value;

[0035] determine a sixth adjustment value according to the current thermal power and a third power limit value, determine a seventh adjustment value according to the current thermal power and a fourth power limit value, and take the intermediate value among the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value;

[0036] when the current thermal power is within a preset range, output the eighth adjustment value to a primary frequency modulation system, so that the primary frequency modulation system adjusts the output power of the generator set according to the eighth adjustment value.

[0037] Optionally, before determining the first adjustment value according to the current power of the generator set and a first power limit value, the method further comprises:

[0038] when the current power is greater than or equal to the first power limit value, determine the power adjustment value according to a frequency deviation value and a second preset relationship; wherein the frequency deviation value is the difference between the grid frequency of the primary frequency modulation and the target frequency.

[0039] Optionally, the primary frequency modulation control method further comprises:

[0040] when the current thermal power has data abnormality, stop outputting the eighth adjustment value.

[0041] The technical scheme of the embodiment of the application limits the power adjustment value through the first power limiting module, the second power limiting module and the third power limiting module, obtains the final adjustment value (the eighth adjustment value), and adjusts the output power of the generator set by using the final adjustment value, so that the current power of the generator set is not excessively large or small after being added or subtracted by the final adjustment value, and the current power is not excessively large after being added by the adjustment value, so that the thermal power of the reactor is not excessively large and exceeds the rated thermal power. In this way, the safety of the reactor is improved while the grid frequency is adjusted.

[0042] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the application, nor to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0044] Figure 1 is a structural schematic diagram of a primary frequency modulation control system provided by an embodiment of the present application;

[0045] Figure 2 is a structural schematic diagram of another primary frequency modulation control system provided by an embodiment of the present application;

[0046] Figure 3 is a structural schematic diagram of another primary frequency modulation control system provided by an embodiment of the present application;

[0047] Figure 4 is a flow chart of a primary frequency modulation control method provided by an embodiment of the present application;

[0048] Figure 5 is a flow chart of another primary frequency modulation control method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0050] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0051] In nuclear power generation, heat energy is generated by nuclear fission or nuclear fusion in a nuclear reactor, and a generator set converts the heat energy into electric energy and outputs the generated electric energy to a power grid. When the frequency of the power grid deviates from a target frequency, a primary frequency modulation system needs to adjust the output power of the generator set so that the frequency of the power grid is consistent with the target frequency. When the primary frequency modulation system adjusts the power of the generator set, it may cause the heat power of the reactor to be too large or too small, reducing the safety of the reactor. Therefore, before determining the adjustment value, the adjustment value needs to be adjusted according to the power of the generator set and the heat power of the reactor to ensure that the heat power of the reactor is within a preset range and ensure the safety of the reactor.

[0052] To solve the above technical problems, the embodiment provides a primary frequency modulation control system. Figure 1 is a structural schematic diagram of a primary frequency modulation control system provided by the embodiment of the application, referring to Figure 1 The primary frequency modulation control system comprises a first power limiting module 110, a second power limiting module 120, a third power limiting module 130 and a first switching module 140. The first power limiting module 110 is configured to determine a first adjustment value according to the current power P01 of the generator set and a first power limit value P1, determine a second adjustment value according to the current power P01 and a second power limit value P2, and take the intermediate value of the first adjustment value and the second adjustment value as a third adjustment value. The second power limiting module 120 is connected with the first power limiting module 110. The second power limiting module 120 is configured to determine a fourth adjustment value according to the current heat power P02 of the reactor and a first preset relationship, and take the smaller value of the third adjustment value and the fourth adjustment value as a fifth adjustment value. The third power limiting module 130 is connected with the second power limiting module 120. The third power limiting module 130 is configured to determine a sixth adjustment value according to the current heat power P02 and a third power limit value P3, determine a seventh adjustment value according to the current heat power P02 and a fourth power limit value P4, and take the intermediate value of the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value. The first switching module 140 is connected with the third power limiting module 130. The first switching module 140 is configured to output the eighth adjustment value to the primary frequency modulation system 210 when the current heat power P02 is within a preset range, so that the primary frequency modulation system 210 adjusts the output power of the generator set according to the eighth adjustment value.

[0053] The first power regulation value I0 is, for example, a power regulation value output by a primary frequency modulation function according to a grid frequency and a target frequency. The second power limit P2 is greater than the first power limit PI, for example, that is, the first power limit PI is a lower limit of the power of the generator set, and the second power limit P2 is an upper limit of the power of the generator set; the first power limit PI is, for example, 80% (80% of the rated power of the generator set), and can also be 70%, or 60%, which is not limited herein, and the second power limit P2 is, for example, 100% (100% of the rated power of the generator set). The first power limiting module 110 determines the first regulation value according to the current power P01 of the generator set and the first power limit PI, for example, subtracting the greater one of the first power limit PI and the current power P01 from the first power limit PI, so that the first regulation value is not too large, and the power value after being regulated according to the first regulation value is not less than the first power limit PI. Similarly, the first power limiting module 110 determines the second regulation value according to the current power P01 and the second power limit P2, for example, subtracting the smaller one of the second power limit P2 and the current power P01 from the second power limit P2, so that the second regulation value is not too large, and the power value after being regulated according to the second regulation value is not greater than the second power limit P2.

[0054] The first preset relationship is, for example, a corresponding relationship between the thermal power of the reactor and the regulation value, which is stored in the form of a table, a curve or a function. The second power limiting module 120 substitutes the current thermal power of the reactor into the first preset relationship to find the fourth regulation value.

[0055] The fourth power limit P4 is greater than the third power limit P3, for example, that is, the third power limit P3 is a lower limit of the thermal power of the reactor, and the fourth power limit P4 is an upper limit of the thermal power of the reactor. The third power limit P3 is, for example, 80% (80% of the rated thermal power of the reactor), and can also be 70%, which is not limited herein, and the fourth power limit P4 is, for example, 100%. The third power limiting module 130 determines the sixth regulation value according to the current thermal power P02 and the third power limit P3, for example, subtracting the greater one of the third power limit P3 and the current thermal power P02 from the third power limit P3, so that the sixth regulation value is not too large, and the power value after being regulated according to the sixth regulation value is not less than the third power limit P3. Similarly, the third power limiting module 130 determines the seventh regulation value according to the current thermal power P02 and the fourth power limit P4, for example, subtracting the smaller one of the fourth power limit P4 and the current thermal power P02 from the fourth power limit P4, so that the seventh regulation value is not too large, and the power value after being regulated according to the seventh regulation value is not greater than the fourth power limit P4.

[0056] Specifically, by taking the intermediate value among the power adjustment value I0, the first adjustment value and the second adjustment value as the third adjustment value, the adjustment value output by the first power limiting module 110 can neither be too large nor too small, the adjustment of the adjustment value is limited, the current power P0 and the adjustment value are added or subtracted to avoid exceeding the safe power range, for example, [P1, P2], and the thermal power of the reactor is avoided to be too large or too small. By taking the smaller value between the third adjustment value and the fourth adjustment value as the fifth adjustment value, the adjustment value output by the second power limiting module 120 is small, and the current power P0 and the adjustment value are added to avoid being too large, and the thermal power of the reactor is large. By taking the intermediate value among the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as the eighth adjustment value, the adjustment value output by the third power limiting module 130 can neither be too large nor too small, and the current power P0 and the adjustment value are added to avoid being too large, and the thermal power of the reactor is large, exceeding the rated thermal power, thereby limiting the power adjustment value and improving the safety of the generator set. By outputting the adjusted eighth adjustment value to the primary frequency modulation system 210, the primary frequency modulation system 210 adjusts the output power of the generator set according to the eighth adjustment value (for example, adjusts the steam quantity of the generator turbine according to the eighth adjustment value, thereby adjusting the output power of the generator set), thereby adjusting the grid frequency while ensuring the safety of the reactor. Moreover, the eighth adjustment value is output to the primary frequency modulation system 210 only when the current thermal power P02 is within the preset range, further ensuring the safety of the reactor.

[0057] In addition, when adjusting the thermal power of the reactor, that is, using the second power limiting module 120 and the third power limiting module 130 to adjust, the reactor power regulation system action can be performed only after the turbine generator set power changes and causes the water temperature of the reactor side primary loop to change, and the thermal power of the reactor can change after a certain period of time. Therefore, the technical solution of the present embodiment first limits the power of the generator set by setting the first limiting module 110, so that the adjustment value added or subtracted from the current power of the generator set will not exceed 100% of its rated power. The rated power of the generator set is related to the rated thermal power of the reactor, so by using this correspondence, the power adjustment value is first adjusted according to the power limitation of the generator set, and then the power adjustment value is adjusted according to the limitation of the thermal power of the reactor, that is, the first power limiting module is executed first, which can improve the rate of power adjustment and ensure that it will not be over-adjusted, avoiding the thermal power of the reactor exceeding 100% of its rated thermal power, which is beneficial to improving the safety of the reactor.

[0058] The technical scheme of the embodiment limits the power adjustment value through the first power limiting module, the second power limiting module and the third power limiting module, obtains the final adjustment value (the eighth adjustment value), and adjusts the output power of the generator set by using the final adjustment value, so that the current power of the generator set is not too large or too small after being added or subtracted by the final adjustment value, the current power is not too large after being added by the adjustment value, and the thermal power of the reactor is not too large to exceed the rated thermal power. In this way, the safety of the reactor is improved while the power grid frequency is adjusted.

[0059] On the basis of the above technical scheme, the modules in the primary frequency modulation control system are further described below, but not as a limitation of the present application.

[0060] Figure 2 is another structure diagram of a primary frequency modulation control system provided by the embodiment of the present application. Optionally, refer to Figure 2 The first power limiting module 110 includes a first high selection unit 111, a first calculation unit 112, a second high selection unit 113, a first low selection unit 114, a second calculation unit 115 and a second low selection unit 116. The first high selection unit 111 is connected to the first power limit value P1 and the current power P01, and is configured to output a first larger value of the first power limit value P1 and the current power P01. The first calculation unit 112 is connected to the first high selection unit 111 and connected to the first power limit value P1, and is configured to calculate a first difference value of the first power limit value P1 and the first larger value, and take the first difference value as a first adjustment value I1. The second high selection unit 113 is connected to the first calculation unit 112 and connected to the power adjustment value I0, and is configured to output a second larger value of the first adjustment value I1 and the power adjustment value I0. The first low selection unit 114 is connected to the second power limit value P2 and the current power P01, and is configured to output a first smaller value of the second power limit value P2 and the current power P01. The second calculation unit 115 is connected to the second power limit value P2 and connected to the first low selection unit 114, and is configured to calculate a second difference value of the second power limit value P2 and the first smaller value, and take the second difference value as a second adjustment value I2. The second low selection unit 116 is connected to the second high selection unit 113 and the second calculation unit 115, and is configured to output a smaller value of the second larger value and the second adjustment value I2 as a third adjustment value I3.

[0061] Specifically, the first high selection unit 111 is implemented by a first high value selector HS1 for example, which outputs the larger value of the two input values, that is, the first larger value of the first power limit P1 and the current power P01. The first calculation unit 112 is implemented by a difference calculator for example, the positive terminal of the first calculation unit 112 is connected to the first power limit P1, and the negative terminal of the first calculation unit 112 is connected to the first larger value, then the first difference output by the first calculation unit 112 is the difference between the first power limit P1 and the first larger value, and the first adjustment value I1 is obtained. The second high selection unit 113 is implemented by a second high value selector HS2 for example, which selects the second larger value of the first adjustment value I1 and the power adjustment value I0.

[0062] Similarly, the first low selection unit 114 is implemented by a first low value selector LS1 for example, which outputs the smaller value of the two input values, that is, the first smaller value of the second power limit P2 and the current power P0. The second calculation unit 115 is implemented by a difference calculator for example, the positive terminal of the second calculation unit 115 is connected to the second power limit P2, and the negative terminal of the second calculation unit 115 is connected to the first smaller value, then the second difference output by the second calculation unit 115 is the difference between the second power limit P2 and the first smaller value, and the second adjustment value I2 is obtained. The second low selection unit 116 is implemented by a second low value selector LS2 for example, which selects the smaller value of the second adjustment value I2 and the second larger value as the third adjustment value I3.

[0063] In this way, the first adjustment value I1 is prevented from being too small, and the power value adjusted according to the first adjustment value I1 is prevented from being less than the first power limit P1. The second adjustment value I2 is prevented from being too large, and the power value adjusted according to the second adjustment value I2 is prevented from being greater than the second power limit P2. The third adjustment value I3 output by the first power limiting module 110 is neither too large nor too small, and the limitation of the adjustment value is achieved.

[0064] For example, the current power P01 of the generator set is 81%, the first power limit P1 is 80%, the second power limit P2 is 100%, and the power adjustment value I0 is -3% for example. After the first high selection unit 111, the first larger value 81% is output, the first calculation unit 112 calculates and outputs the first difference (the first adjustment value I1) of -1%, and the second high selection unit 112 selects the larger value -1%. After the first low selection unit 114, the first smaller value 81% is output, the second calculation unit 115 calculates and outputs the second adjustment value I2 of 19%, and after the second low selection unit 116, the third adjustment value I3 of -1% is selected. When -1% is added to the current power P01 (81%), it will not be less than the first power limit P1, so that the output power of the generator set is within the safe range.

[0065] Optionally, continuing to refer toFigure 2 The second power limiting module 120 comprises a third calculating unit 121 and a third low-selecting unit 122. The third calculating unit 121 accesses the current thermal power P02, and is configured to determine a fourth adjusting value I4 according to the first preset relationship between the current thermal power P02 and the first adjusting value I1. The third low-selecting unit 122 accesses the third adjusting value I3 and is connected with the third calculating unit 121. The third low-selecting unit 122 is configured to output the smaller one of the third adjusting value I3 and the fourth adjusting value I4 as a fifth adjusting value I5.

[0066] Specifically, the third calculating unit 121 substitutes the current thermal power P02 into the first preset relationship, for example, a function Q(X), for example, X+Y≤100%, and Y≤100%-X, where X is the current thermal power, and Y is the fourth adjusting value. Through the function Q(X), the fourth adjusting value I4 can be limited so that the thermal power adjusted according to the fourth adjusting value I4 is less than 100% of the rated thermal power. Through the third low-selecting unit 122, the smaller one of the third adjusting value I3 and the fourth adjusting value I4 is output as the fifth adjusting value I5, so as to further limit the adjusting value, avoiding that the fifth adjusting value I5 is too large and the power value adjusted according to the fifth adjusting value I5 is greater than 100% of the rated thermal power.

[0067] For example, the current thermal power P02 is 99%, and after being substituted into the first preset relationship, the fourth adjusting value I4 is 1%, and the third adjusting value I3 is 1.5%. After passing through the third low-selecting unit 122, the fifth adjusting value I5 is 1%. When 1% is added to the current power P01 (98.5%), the output power of the generator set is small, so that the thermal power of the reactor is not too large, and the safety of the reactor is improved.

[0068] In addition, the first power limiting module 110, the second power limiting module 120 and the third power limiting module 130 are connected in sequence, that is, the power adjusting value is first adjusted according to the limitation of the power of the generator set, then the power adjusting value is adjusted according to the function Q(X), and finally the power adjusting value is adjusted according to the limitation of the thermal power of the reactor. The first power limiting module 110 adjusts the power adjusting value according to the limitation of the power of the generator set, which can more directly and quickly determine the adjusting value of the generator set according to the limitation of the power of the generator set. The function Q(X) is set in the middle, and the fourth adjusting value I4 output by the function Q(X) has a certain adjusting margin, so that the constraint is performed in advance, and the overshoot can be avoided. Finally, the power adjusting value is adjusted according to the limitation of the thermal power of the reactor, which further limits the power adjusting value, so as to further ensure that the power of the generator set and the adjusting value after addition and subtraction do not make the thermal power of the reactor exceed 100% of the rated thermal power, and the safety of the reactor is effectively improved.

[0069] Optionally, with reference to Figure 2 The third power limiting module 130 comprises a third high selection unit 131, a fourth calculation unit 132, a fourth high selection unit 133, a fourth low selection unit 134, a fifth calculation unit 135 and a fifth low selection unit 136. The third high selection unit 131 is connected to the third power limit P3 and the current thermal power P02, and is configured to output a third larger value between the third power limit P3 and the current thermal power P02. The fourth calculation unit 132 is connected to the third high selection unit 131 and connected to the third power limit P3, and is configured to calculate a third difference between the third power limit P3 and the third larger value, and output the third difference as a sixth adjustment value I6. The fourth high selection unit 133 is connected to the fourth calculation unit 132 and connected to the fifth adjustment value I5, and is configured to output a fourth larger value between the fifth adjustment value I5 and the sixth adjustment value I6. The fourth low selection unit 134 is connected to the fourth power limit P4 and the current thermal power P02, and is configured to output a third smaller value between the fourth power limit P4 and the current thermal power P02. The fifth calculation unit 135 is connected to the fourth power limit P4 and connected to the fourth low selection unit 134, and is configured to calculate a fourth difference between the fourth power limit P4 and the third smaller value, and output the fourth difference as a seventh adjustment value I7. The fifth low selection unit 136 is connected to the fourth high selection unit 133 and the fifth calculation unit 135, and is configured to output a smaller value between the fourth larger value and the seventh adjustment value I7 as an eighth adjustment value I8.

[0070] Specifically, the third high selection unit 131 is implemented by a third high value selector HS3, which selects and outputs a third larger value between the third power limit P3 and the current thermal power P02. The fourth calculation unit 132 is implemented by a difference calculator, which inputs the third power limit P3 at a positive terminal and inputs the third larger value at a negative terminal, and outputs a third difference between the third power limit P3 and the third larger value as the sixth adjustment value I6. The fourth high selection unit 133 is implemented by a fourth high value selector HS4, which selects a fourth larger value between the third difference and the sixth adjustment value I6.

[0071] The fourth low selection unit 134 is implemented by a fourth low value selector LS4, for example, which selects the third smaller value between the fourth power limit value P4 and the current thermal power P02. The fifth calculation unit 135 is implemented by a difference calculator, for example, which has the fourth power limit value P4 input to the positive terminal and the third smaller value input to the negative terminal, and outputs a fourth difference value, which is the difference between the fourth power limit value P4 and the third smaller value, as a seventh adjustment value I7. The fifth low selection unit 136 is implemented by a fifth low value selector LS5, for example, which selects the smaller value between the fourth larger value and the seventh adjustment value I7 as an eighth adjustment value I8.

[0072] In this way, the fifth adjustment value I5 is prevented from being too small, and the thermal power value after adjustment according to the fifth adjustment value I5 is prevented from being less than the third power limit value P3. The seventh adjustment value I7 is prevented from being too large, and the power value after adjustment according to the seventh adjustment value I7 is prevented from being greater than the fourth power limit value P4. The eighth adjustment value I8 output by the third power limit module 130 is neither too large nor too small, and the adjustment value is limited, so that the thermal power of the reactor after adjustment is prevented from being too large, and the safety of the reactor is improved.

[0073] For example, the current thermal power P02 is 81%, the third power limit value P3 is 80%, and the fourth power limit value P4 is 100%. After the third high selection unit 131, 81% is output, and after the fourth calculation unit 132, a difference value (sixth adjustment value I6) of -1% is output. The fifth adjustment value I5 is -3%, for example. After the fourth high selection unit 133, -1% is output. After the fourth low selection unit 134, the smaller value 81% is output, and after the fifth calculation unit 135, a difference value (seventh adjustment value I7) of 19% is output. After the fifth low selection unit 136, the eighth adjustment value I8 of -1% is output. The eighth adjustment value I8 is small, and the thermal power of the reactor will not exceed the maximum limit value (the fourth power value) nor be lower than the minimum limit value (the third power limit value), and the safety of the reactor is improved.

[0074] Optionally, continuing to refer to Figure 2 The primary frequency control system further includes a second switching module 150 and a primary adjustment module 160. The second switching module 150 inputs a frequency deviation value f1, and is configured to output the frequency deviation value f1 when the current power P01 is greater than or equal to the first power limit value P1. The frequency deviation value f1 is the difference between the primary frequency f01 and the target frequency f02. The primary adjustment module 160 is connected to the second switching module 150, and is configured to determine a power adjustment value I0 according to the frequency deviation value f1 and a second preset relationship.

[0075] Specifically, the second preset relationship is stored in the form of a table, a curve or a function, for example, and is a corresponding relationship between a frequency deviation value and a power adjustment value. The power adjustment value I0 is obtained by substituting the difference between the grid frequency f01 and the target frequency f02 (the frequency deviation value f1) into the second preset relationship. However, when determining the power adjustment value I0, only how to adjust the output power of the generator set to make the grid frequency reach or approach the target frequency is considered, and whether the thermal power of the reactor is too large or too small after the current power of the generator set is added or subtracted by the power adjustment value I0 is not considered. The scheme of the embodiment, by inputting the power adjustment value I0 into the first power limiting module 110, limiting the power adjustment value I0 according to the current power P01 of the generator set and the first power limit value P1 and the second power limit value P2 of the generator set, so that the third adjustment value I3 output by the first power limiting module 110 will not be too large or too small after being added or subtracted by the current power P01. By the second power limiting module 120 and the third power limiting module 130, the third adjustment value I3 is further limited according to the current thermal power P02 of the reactor, the third power limit value P3 and the fourth power limit value P4 of the reactor, so that the eighth adjustment value I8 output by the third power limiting module 130 will not be too large or too small after being added or subtracted by the current power P01, which improves the safety of the reactor.

[0076] Optionally, with reference to Figure 2 The primary frequency control system further comprises a first enabling module 170. The first enabling module 170 is connected to the current power P01 and the first power limit value P1, and is configured to enable the second switching module 150 when the current power P01 is greater than or equal to the first power limit value P1.

[0077] Specifically, the first enabling module 170 compares the current power P01 with the first power limit value P1. When the current power is greater than or equal to the first power limit value P1, it indicates that the output power of the generator set meets the power adjustment limit requirement. At this time, the first enabling module 170 outputs an enabling signal to the second switching module 150, and the second switching module 150 outputs the frequency deviation value f1.

[0078] For example, with reference to Figure 2 The first enabling module 170, for example, comprises a first difference calculator 171 and a first comparator 172. The first difference calculator 171 calculates the difference between the current power P01 and the first power limit value P1, and the first comparator 172 outputs an enabling signal when the difference between the current power P01 and the first power limit value P1 is greater than 0. After the second switching module 150 receives the enabling signal, the frequency deviation value f1 is output.

[0079] For example, with reference to Figure 2The second switching module 150 is implemented, for example, by a switcher. The S terminal of the switcher receives the frequency deviation value f1, the A terminal of the switcher is connected to the first enabling module 170, and the R terminal of the switcher receives the setting value Set, which is, for example, 0%. Thus, when the second switching module 150 receives the enabling signal from the first enabling module 170, it will output the frequency deviation value f1.

[0080] For example, refer to Figure 2 The primary frequency control system also includes a second difference calculator 173, which takes the grid frequency f01 and the target frequency f02 as input, calculates the frequency deviation value f1 between the grid frequency f01 and the target frequency f02, and outputs the frequency deviation value f1 to the second switching module 150.

[0081] Optionally, continue to refer to Figure 2 The primary frequency control system also includes: a second enabling module 180; the second enabling module 180 is connected to the current thermal power P02, the third power limit P3 and the fourth power limit P4, and the second enabling module 180 is used to enable the first switching module 140 when the current thermal power P02 is greater than or equal to the third power limit P3 and less than or equal to the fourth power limit P4.

[0082] Specifically, the second enabling module 180 compares the current thermal power P02 with the third power limit P3 and the fourth power limit P4, respectively. If the current thermal power P02 is less than the third power limit P3 or greater than the fourth power limit P4, it indicates that the current thermal power P02 of the reactor is in an abnormal state (too high or too low). In this case, the output power of the generator set will not be adjusted. When the current thermal power P02 is greater than or equal to the third power limit P3 and less than or equal to the fourth power limit P4, the thermal power of the reactor is in a normal state, and the output power of the generator set can be adjusted. The second enabling module 180 will then output an enabling signal to the first switching module 140, enabling the first switching module 140. Thus, the first switching module 140 will only output the final adjustment value (eighth adjustment value I8) when the current thermal power P02 is greater than or equal to the third power limit P3 and less than or equal to the fourth power limit P4, thereby improving the safety of the reactor.

[0083] For example, the second enabling module 180 includes a third difference calculator 181, a second comparator 182, a fourth difference calculator 183, a third comparator 184 and a first logic device 185. The third difference calculator 181 inputs the third power limit P3 and the current thermal power P02, and calculates the difference between the current thermal power P02 and the third power limit P3. The second comparator 182 compares the difference between the current thermal power P02 and the third power limit P3 with 0. When the difference between the current thermal power P02 and the third power limit P3 is greater than 0, the second comparator 182 outputs a valid level (e.g. high level). The fourth difference calculator 183 inputs the fourth power limit P4 and the current thermal power P02, and calculates the difference between the current thermal power P02 and the fourth power limit P4. The third comparator 184 judges whether the difference between the current thermal power P02 and the fourth power limit P4 is less than 0. When the difference between the current thermal power P02 and the fourth power limit P4 is less than 0, the third comparator 184 outputs a valid level. The first logic device 185, for example, is an AND logic device. When the first logic device 185 receives the valid levels outputted by the second comparator 182 and the third comparator 184, the first logic device 185 outputs an enabling signal. The first switching module 140 outputs the eighth adjustment value I8 when receiving the enabling signal outputted by the second enabling module 180.

[0084] Figure 3 is a structure diagram of another frequency modulation control system provided by the embodiment of the present application. Optionally, referring to Figure 3 The frequency modulation control system further includes a data judging device 310, a delay device 320, a second logic device 330 and a third logic device 340. The data judging device 310 is connected to the current thermal power P02 of the reactor, and judges the current thermal power P02. When the data is abnormal, for example, the difference between two data is large, the data is too small or the data is negative, the data judging device 310 outputs a valid level signal to the delay device 320. The delay device 320 delays for a period of time, and outputs a valid level (e.g. high level 1) to the second logic device 330 when the data is still abnormal. The second logic device 330, for example, is an OR device. When the second logic device 330 receives the valid level outputted by the delay device 320 and the valid level is greater than or equal to 1, the second logic device 330 outputs a valid level to the third logic device 340. The third logic device 340, for example, is an SR flip-flop. When the R end of the third logic device 340 receives the valid level, the third logic device 340 outputs an invalid level (e.g. low level 0) to the first switching module 140. The first switching module 140 will not output the eighth adjustment value I8, so as to avoid the error of the outputted adjustment value and disturb the operation of the generator set.

[0085] Optionally, continuing to refer to Figure 3The primary frequency control system further comprises a start button and a fourth logic device 350, for example, a NAND device.

[0086] Optionally, referring to Figure 3 The primary frequency control system further comprises a third switch module 360, the data judging device 310 is connected with the third switch module 360, the third switch module 360 is connected with the current thermal power P02 of the reactor, and the third switch module 360 is connected with the second power limiting module 120 and the third power limiting module 130 respectively. The third switch module 360 is realized by a switch, for example. When the data judging device 310 judges that the data is normal, the data judging device 310 outputs a non-enable signal to the third switch module 360, and the third switch module 360 outputs the current thermal power P02 to the second power limiting module 120 and the third power limiting module 130.

[0087] Optionally, referring to Figure 3 The primary frequency control system further comprises an exit button, the exit button is connected with the second logic device 330, and after the exit button is pressed, the second logic device 330 outputs a valid level to the third logic device 340. After the R end of the third logic device 340 receives the valid level, the third logic device 340 outputs an invalid level (for example, a low level 0) to the first switch module 140, so that the first switch module 140 does not output the eighth adjustment value I8, and the exit operation of the control system is realized.

[0088] The technical scheme of the embodiment further provides a primary frequency control method, and the primary frequency control method is realized by the primary frequency control system provided by any of the above embodiments. Figure 4 The technical scheme of the embodiment further provides a primary frequency control method, and the primary frequency control method is realized by the primary frequency control system provided by any of the above embodiments. Figure 4 The primary frequency control method comprises the following steps.

[0089] S410, determining a first adjustment value according to the current power of the generator set and the first power limit value, determining a second adjustment value according to the current power and the second power limit value, and taking an intermediate value of the primary adjustment power adjustment value, the first adjustment value and the second adjustment value as a third adjustment value.

[0090] Specifically, the first adjustment value is determined according to the current power of the generator set and the first power limit value, for example, the larger value of the first power limit value minus the current power and the first power limit value, so that the first adjustment value is not too large, and the power value adjusted according to the first adjustment value is not less than the first power limit value. Similarly, the second adjustment value is determined according to the current power and the second power limit value, for example, the smaller value of the second power limit value minus the current power and the second power limit value, so that the second adjustment value is not too large, and the power value adjusted according to the second adjustment value is not greater than the second power limit value. By taking the intermediate value of the power adjustment value, the first adjustment value and the second adjustment value as the third adjustment value, the output adjustment value can be neither too large nor too small, the limitation of the adjustment value is realized, the current power plus or minus the adjustment value does not exceed the safe power range, and the thermal power of the reactor is prevented from being too large or too small.

[0091] S420, determining a fourth adjustment value according to the current thermal power of the reactor and the first preset relationship, and taking the smaller value of the third adjustment value and the fourth adjustment value as a fifth adjustment value.

[0092] Specifically, by taking the smaller value of the third adjustment value and the fourth adjustment value as the fifth adjustment value, the output adjustment value is small, and the current power plus the adjustment value is not large, so that the thermal power of the reactor does not exceed the power.

[0093] S430, determining a sixth adjustment value according to the current thermal power and the third power limit value, determining a seventh adjustment value according to the current thermal power and the fourth power limit value, and taking the intermediate value of the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value.

[0094] Specifically, by taking the intermediate value of the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as the eighth adjustment value, the output adjustment value can be neither too large nor too small, the current power plus the adjustment value is not large, so that the thermal power of the reactor is not large and exceeds the rated thermal power, thereby realizing the limitation of the power adjustment value and improving the safety of the generator set.

[0095] S440, when the current thermal power is within a preset range, outputting the eighth adjustment value to the primary frequency modulation system, so that the primary frequency modulation system adjusts the output power of the generator set according to the eighth adjustment value.

[0096] Specifically, by outputting the adjusted eighth adjustment value to the primary frequency modulation system, the primary frequency modulation system adjusts the output power of the generator set according to the eighth adjustment value, so that the safety of the reactor is ensured while the grid frequency is adjusted. Moreover, the eighth adjustment value is output to the primary frequency modulation system only when the current thermal power is within a preset range, further ensuring the safety of the reactor.

[0097] Figure 5 is a flowchart of yet another primary frequency control method provided by an embodiment of the present application. Optionally, reference can be made to Figure 5 The primary frequency control method comprises:

[0098] S510, when the current power is greater than or equal to the first power limit value, determining a power adjustment value according to the frequency deviation value and a second preset relationship; wherein the frequency deviation value is the difference between the primary frequency of the power grid and the target frequency.

[0099] Specifically, the current power is compared with the first power limit value, and when the current power is greater than or equal to the first power limit value, it indicates that the output power of the generator set is greater than the lower limit of the power. At this time, the frequency deviation value is substituted into the second preset relationship to determine the power adjustment value.

[0100] S520, determining a first adjustment value according to the current power of the generator set and the first power limit value, determining a second adjustment value according to the current power and the second power limit value, and taking the intermediate value among the primary adjustment power adjustment value, the first adjustment value and the second adjustment value as a third adjustment value.

[0101] S530, determining a fourth adjustment value according to the current thermal power of the reactor and a first preset relationship, and taking the smaller value between the third adjustment value and the fourth adjustment value as a fifth adjustment value.

[0102] S540, determining a sixth adjustment value according to the current thermal power and a third power limit value, determining a seventh adjustment value according to the current thermal power and a fourth power limit value, and taking the intermediate value among the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value.

[0103] S550, when the current thermal power is within a preset range, outputting the eighth adjustment value to the primary frequency control system, so that the primary frequency control system adjusts the output power of the generator set according to the eighth adjustment value.

[0104] Optionally, the primary frequency control method further comprises: when the current thermal power has data anomaly, stopping outputting the eighth adjustment value.

[0105] Specifically, before and during the frequency regulation, data judgment is performed on the current thermal power. If the data is abnormal, for example, the two data are greatly different, the data is too small or the data is negative, etc., the eighth adjustment value will not be outputted, so as to avoid that the output adjustment value has large error and disturbs the operation of the generator set.

[0106] It should be understood that the steps can be reordered, added or deleted using the various forms of the flowchart shown above. For example, the steps described in the present application can be executed in parallel, in sequence or in different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0107] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of specific terminology. However, embodiments thereof can be practiced with the exact description not being set forth but with the same essence; the principles set forth herein can be practiced with plasticity in a manner leading to structurally equivalent devices and / or processes. Therefore, this description is not to be construed as limiting; the scope of the claims will be construed in the broadest context allowed by law.

Claims

1. A primary frequency control system, characterized by, The method comprises the following steps: The first power limiting module is used for determining a first adjustment value according to a current power of the generator set and a first power limit value, determining a second adjustment value according to the current power and a second power limit value, and taking an intermediate value among the once adjusted power adjustment value, the first adjustment value and the second adjustment value as a third adjustment value; The second power limiting module is connected with the first power limiting module and is used for determining a fourth adjustment value according to a current thermal power of the reactor and a first preset relationship, and taking a smaller value among the third adjustment value and the fourth adjustment value as a fifth adjustment value; The third power limiting module is connected with the second power limiting module and is used for determining a sixth adjustment value according to the current thermal power and a third power limit value, determining a seventh adjustment value according to the current thermal power and a fourth power limit value, and taking an intermediate value among the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value; The first switching module is connected with the third power limiting module and is used for outputting the eighth adjustment value to the primary frequency modulation system when the current thermal power is within a preset range, so that the primary frequency modulation system adjusts the output power of the generator set according to the eighth adjustment value; The first power limiting module comprises: The first high selection unit is connected with the first power limit value and the current power and is used for outputting a first larger value among the first power limit value and the current power; The first calculation unit is connected with the first high selection unit and is connected with the first power limit value and is used for calculating a first difference value between the first power limit value and the first larger value and taking the first difference value as the first adjustment value; The second high selection unit is connected with the first calculation unit and is connected with the power adjustment value and is used for outputting a second larger value among the first adjustment value and the power adjustment value; The first low selection unit is connected with the second power limit value and the current power and is used for outputting a first smaller value among the second power limit value and the current power; The second calculation unit is connected with the second power limit value and is connected with the first low selection unit and is used for calculating a second difference value between the second power limit value and the first smaller value and taking the second difference value as the second adjustment value; The second low selection unit is connected with the second high selection unit and the second calculation unit respectively and is used for taking a smaller value among the second larger value and the second adjustment value as the third adjustment value; The second power limiting module comprises: The third calculation unit is connected with the current thermal power and is used for determining the fourth adjustment value according to the current thermal power and the first preset relationship; The third low selection unit is connected with the third adjustment value and is connected with the third calculation unit and is used for outputting a smaller value among the third adjustment value and the fourth adjustment value as the fifth adjustment value.

2. The frequency modulation control system of claim 1, wherein The third power limiting module comprises: The third high selection unit is connected with the third power limit value and the current thermal power and is used for outputting a third larger value among the third power limit value and the current thermal power; a fourth calculation unit, connected with the third high selection unit and accessed to the third power limit, configured to calculate a third difference between the third power limit and the third larger value, and take the third difference as the sixth adjustment value; a fourth high selection unit, connected with the fourth calculation unit and accessed to the fifth adjustment value, configured to output a fourth larger value between the fifth adjustment value and the sixth adjustment value; a fourth low selection unit, accessed to the fourth power limit and the current thermal power, configured to output a third smaller value between the fourth power limit and the current thermal power; a fifth calculation unit, accessed to the fourth power limit and connected with the fourth low selection unit, configured to calculate a fourth difference between the fourth power limit and the third smaller value, and take the fourth difference as the seventh adjustment value; a fifth low selection unit, connected with the fourth high selection unit and the fifth calculation unit respectively, configured to output a smaller value between the fourth larger value and the seventh adjustment value as an eighth adjustment value.

3. The frequency modulation control system of claim 1, wherein Further comprising: a second switching module, accessed to a frequency deviation value, configured to output the frequency deviation value when the current power is greater than or equal to the first power limit; wherein the frequency deviation value is a difference between a grid frequency of primary frequency regulation and a target frequency; a primary adjustment module, connected with the second switching module, configured to determine the power adjustment value according to the frequency deviation value and a second preset relationship.

4. The frequency-agile control system of claim 3, wherein Further comprising: a first enabling module, accessed to the current power and the first power limit, configured to enable the second switching module when the current power is greater than or equal to the first power limit.

5. The frequency-agile control system of claim 1, wherein Further comprising: a second enabling module, accessed to the current thermal power, the third power limit and the fourth power limit, configured to enable the first switching module when the current thermal power is greater than or equal to the third power limit and less than or equal to the fourth power limit.

6. A method of controlling frequency modulation, characterized by, The primary frequency regulation control method is implemented by the primary frequency regulation control system of any one of claims 1-5, and the primary frequency regulation control method comprises: determining a first adjustment value according to a current power of a generator set and a first power limit, determining a second adjustment value according to the current power and a second power limit, and taking an intermediate value among the primary adjustment power adjustment value, the first adjustment value and the second adjustment value as a third adjustment value; determining a fourth adjustment value according to a current thermal power of a reactor and a first preset relationship, and taking a smaller value among the third adjustment value and the fourth adjustment value as a fifth adjustment value; determining a sixth adjustment value according to the current thermal power and a third power limit, determining a seventh adjustment value according to the current thermal power and a fourth power limit, and taking an intermediate value among the fifth adjustment value, the sixth adjustment value and the seventh adjustment value as an eighth adjustment value; when the current thermal power is in a preset range, outputting the eighth adjustment value to a primary frequency regulation system, so that the primary frequency regulation system adjusts an output power of the generator set according to the eighth adjustment value.

7. The method of claim 6, wherein, Before determining the first adjustment value according to the current power of the generator set and the first power limit, further comprising: When the current power is greater than or equal to the first power limit value, the power adjustment value is determined according to a frequency deviation value and a second preset relationship, wherein the frequency deviation value is a difference between a power grid frequency of a first frequency adjustment and a target frequency.

8. The method of claim 6, wherein, Also comprising: When the current thermal power has data abnormality, the eighth adjustment value is stopped from being output.

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