Control device for step disturbance of primary frequency modulation performance test of power plant

Abstract

The utility model relates to the technical field of generator set frequency modulation, and discloses a power plant primary frequency modulation performance test step disturbance control device. Comprising a switching setting unit, an actual rotation speed setting unit, a rated rotation speed setting unit, a test rotation speed number setting unit, a first selection unit, a second selection unit, a first test time setting unit, a second test time setting unit, a rotation speed dead zone judgment unit, a negation unit and a rotation speed difference calculation unit. When in use, the rotating speed dead zone judgment unit is added to generate an effective action signal so as to drive the first test time setting unit to act, and the input of the rotating speed difference calculation unit is set through the output of the first test time setting unit, so that the whole structure has an independent test time control function; and a test rotating speed resetting signal is generated through a negation unit and a second test time setting unit, and is used for a test rotating speed number setting unit with a tracking function to track the input test rotating speed as a rated rotating speed.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency regulation of generator sets, in particular to a control device for a step disturbance in a primary frequency regulation performance test of a power plant. Background Art

[0002] During the operation of the power system's generator set, the frequency will be adjusted through a primary frequency modulation method. For example, when the power system frequency is higher than the normal value, the generator set is required to reduce the active output to restore the power system frequency to the normal value. When the power system frequency is lower than the normal value, the generator set is required to increase the active output to restore the power system frequency to the normal value.

[0003] When the generator set actually performs a frequency modulation control, it is necessary to perform a frequency modulation test on the generator set. Currently, when performing a frequency modulation test, a step disturbance source, namely the test speed, is mostly input manually, and then the speed difference is obtained by subtracting the test speed from the rated speed of the generator set, and then a frequency modulation is performed based on the speed difference.

[0004] The existing primary frequency modulation method has the following problems in actual use:

[0005] First, a frequency modulation test requires time control, but the existing time control is mostly manual timing, that is, the frequency modulation test is stopped after the time is up, which leads to inaccurate timing and affects the operating stability of the generator set. In addition, since the engineer station and the equipment electronic room of the power plant are prohibited from carrying mobile phones and other wireless communication devices, mobile phones cannot be used for timing. If other timing devices are used for timing, the test personnel need to record and analyze data and control equipment, which increases the factor of human error.

[0006] Secondly, the manually input test speed will not automatically restore to a safe value and needs to be restored manually. There is a probability of forgetting to restore, which increases the risk of malfunction of logic control during generator set testing and continues to consume unit energy. Utility Model Content

[0007] In view of the shortcomings of the background technology, the utility model provides a control device for a step disturbance in a primary frequency regulation performance test of a power plant. The technical problem to be solved is that the existing generator set needs manual timing when conducting a primary frequency regulation test, and the input test speed cannot be automatically restored to a safe value and needs to be manually restored.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions: a control device for a step disturbance of a primary frequency regulation performance test of a power plant, comprising a switching setting unit, an actual speed setting unit, a rated speed setting unit, a test speed setting unit with a tracking function, a first selection unit, a second selection unit, a first test time setting unit, a second test time setting unit, a speed dead zone judgment unit, a negation unit and a speed difference calculation unit;

[0009] The first selection unit and the second selection unit both include a selection terminal, a first input terminal, a second input terminal and an output terminal, and the first selection unit and the second selection unit both select the output terminal to be electrically connected to the first input terminal or the second input terminal based on the signal level state of the selection terminal;

[0010] The switching setting unit is electrically connected to the selection end of the first selection unit, and is used to input a control signal to the first selection unit; the actual speed setting unit is electrically connected to the first input end of the first selection unit; the second input end of the first selection unit is electrically connected to the output end of the second selection unit; and the output end of the first selection unit is electrically connected to the first input end of the speed difference calculation unit;

[0011] The rated speed setting unit is electrically connected to the first input end of the second selection unit, the first input end of the speed difference calculation unit and the input end of the test speed setting unit respectively, the output end of the test speed setting unit is electrically connected to the input end of the speed dead zone judgment unit and the second input end of the second selection unit respectively, the output end of the speed dead zone judgment unit is electrically connected to the input end of the first test time setting unit, the output end of the first test time setting unit is electrically connected to the selection end of the first selection unit and the input end of the negation unit respectively, the output end of the negation unit is electrically connected to the input end of the second test time setting unit, and the output end of the second test time setting unit is electrically connected to the setting end of the test speed setting unit;

[0012] When the level of the setting end of the test speed setting unit is high, the output of the output end of the test speed setting unit is the same as the input of the input end of the test speed setting unit, and the test speed setting unit can be manually set when the level of the setting end is low;

[0013] The speed dead zone judgment unit outputs a high level signal when the input data exceeds the upper and lower limit intervals, and the first test time setting unit and the second test time setting unit output high level signals within the preset test time when high level signals are input.

[0014] In some implementations, the output end of the second selection unit is electrically connected to the second input end of the first selection unit via a limiting unit, and the limiting unit is used to limit the upper and lower limits of data input to the second selection unit.

[0015] In a certain embodiment, the utility model further includes a power factor calculation unit, and the output end of the rotation speed difference calculation unit is electrically connected to the power factor calculation unit.

[0016] In a certain embodiment, the utility model further comprises a valve position factor calculation unit, and the output end of the rotation speed difference calculation unit is electrically connected to the valve position factor calculation unit.

[0017] In a certain embodiment, the utility model further includes a frequency modulation control unit, and the output end of the rotation speed difference calculation unit is electrically connected to the frequency modulation control unit.

[0018] In a certain embodiment, the frequency modulation control unit includes an absolute value unit, a second high limit judgment unit and a switch output unit, the output end of the speed difference calculation unit is electrically connected to the input end of the absolute value unit, the output end of the absolute value unit is electrically connected to the input end of the high limit judgment unit, and the output end of the high limit judgment unit is electrically connected to the switch output unit.

[0019] In a certain embodiment, when the generator set operates normally, the switching setting unit inputs a low-level control signal to the selection end of the first selection unit.

[0020] In a certain embodiment, when the generator set is tested, the switching setting unit inputs a high-level control signal to the selection end of the first selection unit.

[0021] In a certain embodiment, when the generator set is tested, the speed manually set and input by the test speed setting unit is greater than the upper limit of the speed dead zone judgment unit or less than the lower limit of the speed dead zone judgment unit.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] First, in actual use, the utility model generates an effective action signal by adding a speed dead zone judgment unit to drive the first test time setting unit to act, and sets the input of the speed difference calculation unit through the output of the first test time setting unit, so that the entire structure has a separate test time control function;

[0024] Secondly, by setting the negation unit and the second test time setting unit to control the level state of the setting end of the test speed setting unit, the utility model can quickly return to a safe value after the test is completed, reducing the risk of human error;

[0025] In addition, the test speed can be limited by setting the limiter unit, which reduces the risk of misoperation and ensures the safety of the test.

[0026] Finally, by setting the switching setting unit, you can control whether to perform the frequency modulation test with one button. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the utility model in the embodiment;

[0028] Figure 2 It is a process diagram of primary frequency modulation performed by the existing primary frequency modulation control device in the embodiment;

[0029] Figure 3 This is a process diagram of a frequency modulation performed by the utility model in the embodiment. DETAILED DESCRIPTION

[0030] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0031] like Figure 1 As shown, a control device for a step disturbance of a primary frequency regulation performance test of a power plant comprises a switching setting unit 1, an actual speed setting unit 2, a rated speed setting unit 3, a test speed setting unit 4 with a tracking function, a first selection unit 5, a second selection unit 6, a first test time setting unit 8, a second test time setting unit 10, a speed dead zone judgment unit 7, a negation unit 9 and a speed difference calculation unit 11;

[0032] The first selection unit 5 and the second selection unit 6 both include a selection terminal F, a first input terminal N, a second input terminal Y and an output terminal OUT. The first selection unit 5 and the second selection unit 6 both select the output terminal OUT to be electrically connected to the first input terminal N or the second input terminal Y based on the signal level state of the selection terminal F.

[0033] The switching setting unit 1 is electrically connected to the selection end of the first selection unit, and is used to input a control signal to the input end F of the first selection unit 5, and the control signal is used to control the output end OUT of the first selection unit 5 to be electrically connected to the first input end N or the second input end Y, the actual speed setting unit 2 is electrically connected to the first input end N of the first selection unit 5, the second input end Y of the first selection unit 5 is electrically connected to the output end OUT of the second selection unit 6, and the output end OUT of the first selection unit 5 is electrically connected to the second input end IN2 of the speed difference calculation unit 11;

[0034] The rated speed setting unit 3 is electrically connected to the first input terminal N of the second selection unit 6, the first input terminal IN1 of the speed difference calculation unit 11 and the input terminal IR of the test speed setting unit 4 respectively; the output terminal OUT of the test speed setting unit 4 is electrically connected to the input terminal IN of the speed dead zone judgment unit 7 and the second input terminal Y of the second selection unit 6 respectively; the output terminal OUT of the speed dead zone judgment unit 7 is electrically connected to the input terminal IN of the first test time setting unit 8; the output terminal OUT of the first test time setting unit 8 is electrically connected to the selection terminal F of the first selection unit 6 and the input terminal IN of the inversion unit 9 respectively; the output terminal of the inversion unit 9 is electrically connected to the input terminal IN of the second test time setting unit 10; the output terminal OUT of the second test time setting unit 10 is electrically connected to the setting terminal TS of the test speed setting unit 4;

[0035] When the level of the setting terminal TS of the test speed setting unit 4 is high, the output of the output terminal OUT of the test speed setting unit 4 is the same as the input of the input terminal TR of the test speed setting unit 4. When the level of the setting terminal TS of the test speed setting unit 4 is low, the test speed setting unit 4 can be manually set.

[0036] The speed dead zone judgment unit 7 outputs a high level signal when the input data exceeds the upper and lower limit intervals, and the first test time setting unit 8 and the second test time setting unit 10 output a high level signal within the preset test time when a high level signal is input.

[0037] Specifically, in this embodiment, the output terminal OUT of the second selection unit 6 is electrically connected to the second input terminal Y of the first selection unit 5 through the limiter unit 12, and the limiter unit 12 is used to limit the upper and lower limits of the data input to the second selection unit 5. In actual use, the limiter unit 12 can ensure that the rotation speed input to the second selection unit 6 is limited, thereby reducing the risk of misoperation and ensuring the safety of the test.

[0038] Specifically, in Figure 1 In the utility model, the power factor calculation unit 13 is further included, and the output end OUT of the speed difference calculation unit 11 is electrically connected to the power factor calculation unit 13. In actual use, the power factor calculation unit 13 is used to convert the calculated speed difference into the corresponding generator power, which is used for the primary frequency modulation load instruction of the generator set, and outputs it through the second switch output unit 14.

[0039] Specifically, in Figure 1In the utility model, the valve position factor calculation unit 15 is further included, and the output end OUT of the speed difference calculation unit 11 is electrically connected to the valve position factor calculation unit 15. In actual use, the valve position factor calculation unit 15 is used to convert the calculated speed difference into a corresponding high-speed valve command signal of the steam turbine, which is used for the primary frequency modulation valve position command of the generator set, directly acts on the high-speed valve, can play a fast response of the primary frequency modulation, and is output through the third switch output unit 16.

[0040] Specifically, in Figure 1 In the present invention, the frequency modulation control unit 17 is further included, and the output end OUT of the speed difference calculation unit 11 is electrically connected to the frequency modulation control unit 17. In actual use, the frequency modulation control unit 17 performs a frequency modulation control based on the output of the speed difference calculation unit 11.

[0041] More specifically, in Figure 1 In the figure, the frequency modulation control unit 17 includes an absolute value unit 170, a second high limit judgment unit 171 and a switch output unit 172, the output end OUT of the speed difference calculation unit 11 is electrically connected to the input end of the absolute value unit 170, the output end of the absolute value unit 170 is electrically connected to the input end of the high limit judgment unit 171, and the output end of the high limit judgment unit 171 is electrically connected to the switch output unit 172.

[0042] It should be noted that each of the switching setting unit 1, the actual speed setting unit 2, the rated speed setting unit 3, the test speed setting unit 4 with tracking function, the first selection unit 5, the second selection unit 6, the first test time setting unit 8, the second test time setting unit 10, the speed dead zone judgment unit 7, the negation unit 9, the speed difference calculation unit 11, the power factor calculation unit 13, the valve position factor calculation unit 15 and the frequency modulation control unit 17 of the utility model is an existing functional unit. The utility model realizes a frequency modulation test of the generator set by selecting these functional units and setting the connection relationship between these functional units.

[0043] In actual use, the working process of the utility model is as follows:

[0044] When the generator set is operating normally, the output of the switching setting unit 1 is set to a low-level signal. At this time, the output of the output terminal OUT of the first selection unit 5 is the same as the input of the first input terminal N of the first selection unit 5, that is, the actual speed set by the actual speed setting unit 2 is selected for output, and then the speed difference calculation unit 11 subtracts the actual speed set by the actual speed setting unit 2 from the rated speed set by the rated speed setting unit 3 to obtain the speed difference, which is input to the power factor calculation unit 13, the valve position factor calculation unit 15 and the frequency modulation control unit 17 for logical action;

[0045] When the generator set needs to perform a frequency modulation test, the output of the switching setting unit 1 is set to a low-level signal. At this time, the output of the output terminal OUT of the first selection unit 5 is the same as the input of the second input terminal Y of the first selection unit 5. Then, the required speed is input into the test speed setting unit 4, and the required speed is input into the speed dead zone judgment unit 7 for high and low limit judgment, wherein the high and low limits can be selected according to actual needs. For example, the high limit can be set to 3000r / min and the low limit can be set to 2998r / min. When the required speed is not within the range, the speed dead zone judgment unit 7 outputs a high-level signal, and the high-level signal enters the first test time setting unit 8, wherein the setting time of the first test time setting unit 8 can be based on Actual demand selection, exemplarily, the test time of the first test time setting unit 8 is 60S. During the test time, the first test time setting unit 8 outputs a high-level signal, which makes the output of the output terminal OUT of the second selection unit 6 the same as the second input terminal Y of the second selection unit 6, that is, the required speed set in the test speed setting unit 4 is selected, and the required speed is input to the second input terminal IN2 of the speed difference calculation unit 11 through the first selection unit 5. The speed difference calculation unit 11 subtracts the required speed from the rated speed set by the rated speed setting unit 3 to obtain the speed difference, which is input to the power factor calculation unit 13, the valve position factor calculation unit 15 and the frequency modulation control unit 17 for logical action;

[0046] During the test time of the first test time setting unit 8, the negation unit 9 outputs a low level signal due to the input of a high level signal. At this time, the second test time setting unit 10 outputs a low level signal, and the low level signal is sent to the setting end TS of the test speed setting unit 4. Then, the output of the output end of the test speed setting unit 4 is still the set required speed.

[0047] After the test time of the first test time setting unit 8, the first test time setting unit 8 outputs a low-level signal, and the low-level signal makes the output terminal OUT of the second selection unit 6 the same as the first input terminal N of the second selection unit 6, which is the rated speed set by the rated speed setting unit 3. The rated speed is input to the speed difference calculation unit 11 through the first selection unit 5. At this time, the speed difference of the speed difference calculation unit 11 is 0, and the primary frequency modulation control does not work; at the same time, since the inversion unit 9 inputs a low-level signal, the inversion unit 9 outputs a high-level signal, and the high-level signal makes the second test time setting unit 10 output a high-level signal, and the high-level signal makes the output of the test speed setting unit 4 the input of the input terminal TR of the test speed setting unit 4, which is the rated speed, thereby doubly ensuring that the output of the second selection unit 6 is the rated speed.

[0048] Assume that the relevant parameter settings for a frequency modulation are as follows:

[0049] a) The step disturbance time of a frequency modulation performance test is generally 60s;

[0050] b) Speed ​​difference limit, the generator set is set according to the needs, specifically: when P<350MW, it is generally ±15.5r / min, when 500MW>P≥350MW, it is generally ±12.8r / min. When P≥500MW, it is generally ±10.1r / min;

[0051] c) The step disturbance recovery time of a frequency modulation performance test is generally 1s;

[0052] d) Speed ​​​​uneven rate, which can be set in the range of 4% to 5%, generally 4.5%;

[0053] e) Rated speed of the generator set, the default value is 3000r / min;

[0054] f) Primary frequency modulation dead zone setting, the dead zone is generally ±2r / min;

[0055] g) The primary frequency modulation power function and valve position function are generally calculated and set based on a speed inequality rate of 4.5%.

[0056] Taking the primary frequency regulation performance test of a normally produced generator set as an example, the primary frequency regulation performance test step disturbance time set by the first test time setting unit 8 is set to 60s, the speed difference limit set by the limit unit 12 is set to ±15.5r / min, the primary frequency regulation performance test step disturbance reset time set by the second test time setting unit 10 is set to 1s, the rated speed setting unit 3 sets the generator set rated speed to 3000r / min, the primary frequency regulation dead zone set by the high and low limit unit 7 is set to ±2r / min, the primary frequency regulation speed inequality rate is set to 4.5%, and the primary frequency regulation load upper and lower limits are 2.5MW.

[0057] The process of testing the existing primary frequency modulation control device is as follows: Figure 2 As shown, from Figure 2 It can be seen that due to manual control and multiple parameter inputs, the test time far exceeds 60s. The test lasts for a long time and the normal operating conditions of the unit have been affected.

[0058] When the utility model is used to conduct a frequency modulation test, the process is as follows: Figure 3 As shown, from Figure 3 It can be seen that the test time is well controlled within 60s, the test duration meets the expected setting value, and the normal operation of the unit is not affected. Compared with manual control, it is more accurate, and only one operation is required throughout the process, and it automatically returns to normal.

[0059] In summary, the utility model generates an effective action signal by adding a speed dead zone judgment unit 7 to drive the first test time setting unit 8 to act, and sets the input of the speed difference calculation unit 11 through the output of the first test time setting unit 8, so that the entire structure has a separate test time control function;

[0060] Secondly, by setting the negation unit 9 and the second test time setting unit 10 to control the level state of the setting end of the test speed setting unit, the utility model can quickly return to a safe value after the test is completed, reducing the risk of human error;

[0061] In addition, by setting the limiter unit 12, the test speed can be limited, reducing the risk of misoperation and ensuring the safety of the test;

[0062] Finally, by setting the switching setting unit 1, whether to perform the frequency modulation test can be controlled by one key.

[0063] The above is based on the enlightenment of this utility model. Through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of ​​this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A control device for step disturbance of primary frequency regulation performance test in power plant, characterized in that: It includes a switching setting unit, an actual speed setting unit, a rated speed setting unit, a test speed setting unit with a tracking function, a first selection unit, a second selection unit, a first test time setting unit, a second test time setting unit, a speed dead zone judgment unit, a negation unit and a speed difference calculation unit; The first selection unit and the second selection unit both include a selection terminal, a first input terminal, a second input terminal and an output terminal, and the first selection unit and the second selection unit both select the output terminal to be electrically connected to the first input terminal or the second input terminal based on the signal level state of the selection terminal; The switching setting unit is electrically connected to the selection end of the first selection unit, and is used to input a control signal to the first selection unit; the actual speed setting unit is electrically connected to the first input end of the first selection unit; the second input end of the first selection unit is electrically connected to the output end of the second selection unit; and the output end of the first selection unit is electrically connected to the second input end of the speed difference calculation unit; The rated speed setting unit is electrically connected to the first input end of the second selection unit, the first input end of the speed difference calculation unit and the input end of the test speed setting unit respectively, the output end of the test speed setting unit is electrically connected to the input end of the speed dead zone judgment unit and the second input end of the second selection unit respectively, the output end of the speed dead zone judgment unit is electrically connected to the input end of the first test time setting unit, the output end of the first test time setting unit is electrically connected to the selection end of the first selection unit and the input end of the negation unit respectively, the output end of the negation unit is electrically connected to the input end of the second test time setting unit, and the output end of the second test time setting unit is electrically connected to the setting end of the test speed setting unit; When the level of the setting end of the test speed setting unit is high, the output of the output end of the test speed setting unit is the same as the input of the input end of the test speed setting unit, and the test speed setting unit can be manually set when the level of the setting end is low; The speed dead zone judgment unit outputs a high level signal when the input data exceeds the upper and lower limit intervals, and the first test time setting unit and the second test time setting unit output high level signals within the preset test time when high level signals are input.

2. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 1 is characterized in that: The output end of the second selection unit is electrically connected to the second input end of the first selection unit through a limiting unit, and the limiting unit is used to limit the upper and lower limits of data input to the second selection unit.

3. A control device for step disturbance in primary frequency regulation performance test of a power plant according to claim 1 or 2, characterized in that: It also includes a power factor calculation unit, and the output end of the rotation speed difference calculation unit is electrically connected to the power factor calculation unit.

4. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 3 is characterized in that: It also includes a valve position factor calculation unit, and the output end of the rotation speed difference calculation unit is electrically connected to the valve position factor calculation unit.

5. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 4, characterized in that: It also includes a frequency modulation control unit, and the output end of the rotation speed difference calculation unit is electrically connected to the frequency modulation control unit.

6. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 5, characterized in that: The frequency modulation control unit includes an absolute value unit, a second high limit judgment unit and a switch output unit, the output end of the speed difference calculation unit is electrically connected to the input end of the absolute value unit, the output end of the absolute value unit is electrically connected to the input end of the high limit judgment unit, and the output end of the high limit judgment unit is electrically connected to the switch output unit.

7. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 1, characterized in that: When the generator set operates normally, the switching setting unit inputs a low-level control signal to the selection end of the first selection unit.

8. The control device for step disturbance of primary frequency regulation performance test of power plant according to claim 1, characterized in that: When the generator set is tested, the switching setting unit inputs a high-level control signal to the selection end of the first selection unit.

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