Swing reactance parameter calculation method applied to PSS and related device

Abstract

The invention discloses a swing reactance parameter calculation method applied to a PSS and a related device, and the method comprises the steps: monitoring the variable quantity and the corresponding time difference of an electromagnetic power signal inputted into the PSS, and obtaining the actual variable quantity and the actual oscillation period of the electromagnetic power; calculating actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value; and if the peak-to-peak value calculated according to the actual variation of the electromagnetic power is greater than a threshold value, selecting an actual swing reactance value, and if not, retaining an initial default value. According to the method and the device, the technical problem of influence on the damping effect of the PSS caused by lack of accuracy and reliability of the calculated rotating speed of the unit due to the fact that the setting problem of the swing reactance parameter is not considered in a targeted manner in the prior art can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method for calculating swing reactance parameters applied to a PSS and related devices. Background Art

[0002] The power-accelerating PSS (Power System Stabilizer) is an additional excitation control technology used to suppress low-frequency oscillations in power systems. Its main function is to provide positive damping torque by adjusting the excitation voltage of the generator to compensate for the negative damping torque generated in the original excitation voltage regulator, thereby improving the damping capacity of the power system and suppressing the occurrence of low-frequency oscillations. The power-accelerating PSS uses the generator speed and electromagnetic power as input signals to obtain an additional excitation control signal that is ahead of the electrical power phase of the unit, thereby suppressing the low-frequency oscillations of the unit.

[0003] At present, the devices of mainstream excitation manufacturers at home and abroad all adopt the electrical quantity calculation method, that is, by collecting the machine-end voltage, machine-end current and swing reactance parameters to calculate the potential in the generator q axis, and then obtain the angular frequency of the potential as the generator speed signal. However, in this process, if the swing reactance parameters are set unreasonably, it will directly affect the accuracy and effectiveness of the unit speed calculation, thereby affecting the damping effect of PSS in different frequency bands to varying degrees. Summary of the invention

[0004] The present application provides a method and related device for calculating the swing reactance parameters applied to PSS, which is used to solve the technical problem that the prior art does not specifically consider the setting problem of the swing reactance parameters, resulting in the lack of accuracy and reliability of the unit speed calculated based on this, thereby affecting the damping effect of the PSS.

[0005] In view of this, the first aspect of the present application provides a method for calculating swing reactance parameters applied to PSS, including:

[0006] Monitor the change of the electromagnetic power signal in the input PSS and the corresponding time difference to obtain the actual change of the electromagnetic power and the actual oscillation period;

[0007] Calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value;

[0008] If the peak-to-peak value calculated according to the actual change in the electromagnetic power is greater than a threshold value, the actual swing reactance value is selected; if not, the initial default value is retained.

[0009] Preferably, the monitoring input PSS changes in the amount of electromagnetic power signal and the corresponding time difference to obtain the actual change in electromagnetic power and the actual oscillation period includes:

[0010] The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power;

[0011] A zero-crossing monitoring method is used to obtain a time difference between two adjacent zero-crossing points of a signal of the actual change amount of the electromagnetic power, and an actual time difference is obtained;

[0012] The actual oscillation period is calculated according to the actual time difference.

[0013] Preferably, the calculating the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain the actual swing reactance value includes:

[0014] calculating an actual oscillation frequency based on the actual oscillation period;

[0015] The actual oscillation frequency is substituted into a preset swing reactance formula to calculate the actual swing reactance, thereby obtaining the actual swing reactance value.

[0016] Preferably, if the peak-to-peak value calculated according to the actual change in the electromagnetic power is greater than a threshold, the actual swing reactance value is selected; if not, the initial default value is retained, and then the method further includes:

[0017] The computer group speed is calculated according to the actual swing reactance value selected;

[0018] Input the unit speed and electromagnetic power into the target PSS to calculate the acceleration power change;

[0019] The acceleration power variation is processed through the lead-lag link and the limit link to generate an additional excitation control signal.

[0020] The second aspect of the present application provides a swing reactance parameter calculation device applied to PSS, comprising:

[0021] A monitoring and extraction unit is used to monitor the change amount and corresponding time difference of the electromagnetic power signal input into the PSS, and obtain the actual change amount and actual oscillation period of the electromagnetic power;

[0022] A reactance calculation unit, used to calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value;

[0023] The reactance selection unit is used to select the actual swing reactance value if the peak-to-peak value calculated based on the actual change of the electromagnetic power is greater than a threshold value, and if not, retain the initial default value.

[0024] Preferably, the monitoring and extracting unit is specifically used for:

[0025] The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power;

[0026] A zero-crossing monitoring method is used to obtain a time difference between two adjacent zero-crossing points of a signal of the actual change amount of the electromagnetic power, and an actual time difference is obtained;

[0027] The actual oscillation period is calculated according to the actual time difference.

[0028] Preferably, the reactance calculation unit is specifically used for:

[0029] calculating an actual oscillation frequency based on the actual oscillation period;

[0030] The actual oscillation frequency is substituted into a preset swing reactance formula to calculate the actual swing reactance, thereby obtaining the actual swing reactance value.

[0031] Preferably, it also includes:

[0032] A speed calculation unit, used for calculating the speed of the computer group according to the selected actual swing reactance value;

[0033] a change calculation unit, used for inputting the unit speed and electromagnetic power into the target PSS to calculate the acceleration power change;

[0034] The signal generating unit is used to process the acceleration power variation through the lead-lag link and the limit link to generate an additional excitation control signal.

[0035] A third aspect of the present application provides a swing reactance parameter calculation device applied to a PSS, the device comprising a processor and a memory;

[0036] The memory is used to store program code and transmit the program code to the processor;

[0037] The processor is used to execute the swing reactance parameter calculation method applied to PSS described in the first aspect according to the instructions in the program code.

[0038] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program codes, and the program codes are used to execute the swing reactance parameter calculation method applied to PSS described in the first aspect.

[0039] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0040] In the present application, a method for calculating the swing reactance parameters applied to PSS is provided, including: monitoring the change in the electromagnetic power signal input into the PSS and the corresponding time difference to obtain the actual change in the electromagnetic power and the actual oscillation period; calculating the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain the actual swing reactance value; if the peak-to-peak value calculated based on the actual change in the electromagnetic power is greater than a threshold value, the actual swing reactance value is selected, if not, the initial default value is retained.

[0041] The swing reactance parameter calculation method applied to PSS provided in the present application determines the actual oscillation period of the unit by detecting the change of electromagnetic power, and then calculates the actual swing reactance value based on the actual oscillation period; in order to be more in line with the actual situation, a peak-to-peak value judgment method is adopted to select a suitable swing reactance value, that is, the actual swing reactance value or the initial default value; this process specifically considers the calculation and selection of the swing reactance parameters, which is more in line with the actual situation, and can ensure the accuracy and reliability of the unit speed calculated based on this parameter, thereby ensuring the damping effect of the PSS. Therefore, the present application can solve the technical problem that the prior art does not specifically consider the setting problem of the swing reactance parameters, resulting in the lack of accuracy and reliability of the unit speed calculated based on this, thereby affecting the damping effect of the PSS. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flow chart of a method for calculating swing reactance parameters applied to a PSS provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of the structure of a swing reactance parameter calculation device for PSS provided in an embodiment of the present application;

[0044] Figure 3 A schematic diagram of a mathematical model of the operating principle of PSS2B (an accelerating power type PSS) provided in an embodiment of the present application;

[0045] Figure 4 A schematic diagram of the principle waveform of the zero-crossing monitoring method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] For easier understanding, see Figure 1, the embodiment of the method for calculating the swing reactance parameters applied to PSS provided by the present application includes:

[0048] Step 101 : monitor the change amount and corresponding time difference of the electromagnetic power signal input into the PSS to obtain the actual change amount and actual oscillation period of the electromagnetic power.

[0049] Furthermore, step 101 includes:

[0050] The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power;

[0051] The zero-crossing monitoring method is used to obtain the time difference between two adjacent zero-crossing points of the signal of the actual change amount of the electromagnetic power, and the actual time difference is obtained;

[0052] Calculate the actual oscillation period based on the actual time difference.

[0053] It should be noted that the actual operation process schematic diagram of the accelerated power PSS can be found in Figure 3 The input signals of PSS include generator speed and electromagnetic power; the electromagnetic power signal After being processed by two washout DC isolation links, the change in electromagnetic power can be obtained. Because it is real-time monitoring, the actual change in electromagnetic power is obtained. The signal processing processes of the two DC isolation links are expressed as follows: and ;in, is a differential operator, and is the DC isolation time constant. The DC isolation link can filter out the steady-state signal and only retain the change.

[0054] See also Figure 4 , the zero-crossing monitoring method can be used to extract the time difference between two adjacent zero-crossing points in the actual change signal of electromagnetic power, that is, the actual time difference, recorded as , and the actual oscillation period can be calculated based on the actual time difference .

[0055] Step 102: Calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value.

[0056] Furthermore, step 102 includes:

[0057] Calculate the actual oscillation frequency based on the actual oscillation period;

[0058] Substitute the actual oscillation frequency into the preset swing reactance formula to calculate the actual swing reactance and obtain the actual swing reactance value.

[0059] The actual oscillation period is , then the actual oscillation frequency can be expressed as The preset swing reactance formula is expressed as:

[0060]

[0061] in, represents the frequency in oscillation mode, That is, the default initial value is taken, and the calculated swing reactance value is also the initial default value; Represents the horizontal axis synchronous reactance, the unit is pu. is the swing reactance value, is the horizontal axis transient time constant when the stator is short-circuited, is the horizontal axis transient time constant when the stator is open circuit, and the unit is s. Substituting this into the formula, we can calculate the actual swing reactance value, which is expressed as In addition, according to the above formula, it can be found that the swing reactance parameters change with the change of the oscillation frequency. By comprehensively considering the angular velocity errors under different oscillation modes and reasonably selecting the oscillation frequency, the appropriate swing reactance value can be calculated.

[0062] Step 103: If the peak-to-peak value calculated based on the actual change in electromagnetic power is greater than the threshold, the actual swing reactance value is selected; if not, the initial default value is retained.

[0063] It should be noted that the initial default value is based on the initial set oscillation frequency Calculate, for example, if , , , , then based on the above formula, the initial default value of the swing reactance can be calculated This is just an example and is not a limitation. The calculation can be set according to the actual situation. It can be seen that this embodiment is to monitor the change of electromagnetic power. , confirm the oscillation frequency and adjust the swing reactance parameters based on this.

[0064] This embodiment selects to monitor the actual change signal of electromagnetic power within an actual oscillation period T time window for analysis, and the maximum value within the time window is With the smallest Subtracting the peak-to-peak value PePP, we can get the peak-to-peak value PePP, and then compare the peak-to-peak value PePP with the threshold. If it is greater than the threshold, the actual swing reactance value is selected. If it is less than or equal to, keep the initial default value By selecting appropriate swing reactance parameters through adaptive judgment, it can be ensured that the parameters are more in line with the actual situation, and the unit speed calculated based on this is more accurate and reliable.

[0065] Furthermore, step 103 further includes:

[0066] The computer group speed is calculated according to the actual swing reactance value selected;

[0067] The unit speed and electromagnetic power are input into the target PSS to calculate the acceleration power change;

[0068] The acceleration power variation is processed through the lead-lag link and the limit link to generate an additional excitation control signal.

[0069] The principle of generating the additional excitation control signal based on the selected swing reactance value can be found in Figure 3 This embodiment mainly uses the actual swing reactance value as an example to illustrate the process. According to the actual swing reactance value, a more accurate unit speed can be calculated. , the electromagnetic power signal With unit speed The target PSS is input for DC isolation processing, the steady-state signal is filtered out, and the electromagnetic power change is obtained. , that is, ; and unit speed change , that is, ,in accordance with and The mechanical power of the generator can be calculated .

[0070] Figure 3 middle, ,in is the unit inertia time constant, ,in The same DC isolation link, and the gain in the PSS action frequency band is close to 1, so .

[0071] in, , so , according to the generator rotor motion equation, , so . After passing through the notch filter function G(s), we get , within the range of PSS, the notch filter gain is close to 1, so , and Subtracting the two gives ,in In order to accelerate the power change, the phase is corrected through the third-order lead-lag link to obtain the excitation additional control signal that is ahead of the unit electrical power phase. , after passing through the limiting link, it is superimposed on the input end of the voltage regulator.

[0072] The swing reactance parameter calculation method applied to PSS provided in the embodiment of the present application determines the actual oscillation period of the unit by detecting the change of electromagnetic power, and then calculates the actual swing reactance value based on the actual oscillation period; in order to be more in line with the actual situation, a peak-to-peak value judgment method is adopted to select a suitable swing reactance value, that is, the actual swing reactance value or the initial default value; this process specifically considers the calculation and selection of the swing reactance parameters, which is more in line with the actual situation, and can ensure the accuracy and reliability of the unit speed calculated based on this parameter, thereby ensuring the damping effect of the PSS. Therefore, the embodiment of the present application can solve the technical problem that the prior art does not specifically consider the setting problem of the swing reactance parameters, resulting in the lack of accuracy and reliability of the unit speed calculated based on this, thereby affecting the damping effect of the PSS.

[0073] For easier understanding, see Figure 2 The present application provides an embodiment of a swing reactance parameter calculation device applied to PSS, including:

[0074] A monitoring and extracting unit 201 is used to monitor the change amount and corresponding time difference of the electromagnetic power signal input into the PSS, and obtain the actual change amount and actual oscillation period of the electromagnetic power;

[0075] A reactance calculation unit 202, used to calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value;

[0076] The reactance selection unit 203 is used to select the actual swing reactance value if the peak-to-peak value calculated according to the actual change of the electromagnetic power is greater than the threshold value, and if not, retain the initial default value.

[0077] Furthermore, the monitoring and extracting unit 201 is specifically used for:

[0078] The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power;

[0079] The zero-crossing monitoring method is used to obtain the time difference between two adjacent zero-crossing points of the signal of the actual change amount of the electromagnetic power, and the actual time difference is obtained;

[0080] Calculate the actual oscillation period based on the actual time difference.

[0081] Further, the reactance calculation unit 202 is specifically used for:

[0082] Calculate the actual oscillation frequency based on the actual oscillation period;

[0083] Substitute the actual oscillation frequency into the preset swing reactance formula to calculate the actual swing reactance and obtain the actual swing reactance value.

[0084] Furthermore, it also includes:

[0085] A speed calculation unit 204, used to calculate the speed of the computer group according to the selected actual swing reactance value;

[0086] The change calculation unit 205 is used to input the unit speed and electromagnetic power into the target PSS to calculate the acceleration power change;

[0087] The signal generating unit 206 is used to process the acceleration power variation through the lead-lag link and the limit link to generate an additional excitation control signal.

[0088] The present application also provides a swing reactance parameter calculation device applied to PSS, the device comprising a processor and a memory;

[0089] The memory is used to store the program code and transmit the program code to the processor;

[0090] The processor is used to execute the swing reactance parameter calculation method applied to PSS in the above method embodiment according to the instructions in the program code.

[0091] The present application also provides a computer-readable storage medium, which is used to store program codes, and the program codes are used to execute the swing reactance parameter calculation method applied to PSS in the above method embodiment.

[0092] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0093] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0094] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0095] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions for executing all or part of the steps of the method described in each embodiment of the present application through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0096] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for calculating swing reactance parameters applied to PSS, characterized in that: include: Monitor the change of the electromagnetic power signal in the input PSS and the corresponding time difference to obtain the actual change of the electromagnetic power and the actual oscillation period; Calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value; If the peak-to-peak value calculated according to the actual change in the electromagnetic power is greater than a threshold value, the actual swing reactance value is selected; if not, the initial default value is retained.

2. The method for calculating swing reactance parameters applied to PSS according to claim 1, characterized in that: The monitoring input PSS includes: The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power; A zero-crossing monitoring method is used to obtain a time difference between two adjacent zero-crossing points of a signal of the actual change amount of the electromagnetic power, and an actual time difference is obtained; The actual oscillation period is calculated according to the actual time difference.

3. The method for calculating swing reactance parameters applied to PSS according to claim 1, characterized in that: The calculating the actual swing reactance based on the actual oscillation period and the preset swing reactance formula to obtain the actual swing reactance value includes: calculating an actual oscillation frequency based on the actual oscillation period; The actual oscillation frequency is substituted into a preset swing reactance formula to calculate the actual swing reactance, thereby obtaining the actual swing reactance value.

4. The method for calculating swing reactance parameters applied to PSS according to claim 1, characterized in that: If the peak-to-peak value calculated according to the actual change in the electromagnetic power is greater than the threshold, the actual swing reactance value is selected; if not, the initial default value is retained, and then the following further includes: The computer group speed is calculated according to the actual swing reactance value selected; Input the unit speed and electromagnetic power into the target PSS to calculate the acceleration power change; The acceleration power variation is processed through the lead-lag link and the limit link to generate an additional excitation control signal.

5. A swing reactance parameter calculation device for PSS, characterized in that: include: A monitoring and extraction unit is used to monitor the change amount and corresponding time difference of the electromagnetic power signal input into the PSS, and obtain the actual change amount and actual oscillation period of the electromagnetic power; A reactance calculation unit, used to calculate the actual swing reactance based on the actual oscillation period and a preset swing reactance formula to obtain an actual swing reactance value; The reactance selection unit is used to select the actual swing reactance value if the peak-to-peak value calculated based on the actual change of the electromagnetic power is greater than a threshold value, and if not, retain the initial default value.

6. The swing reactance parameter calculation device applied to PSS according to claim 5, characterized in that: The monitoring and extraction unit is specifically used for: The electromagnetic power signal input to the PSS is isolated by a DC isolation link to obtain the actual change of the electromagnetic power; A zero-crossing monitoring method is used to obtain a time difference between two adjacent zero-crossing points of a signal of the actual change amount of the electromagnetic power, and an actual time difference is obtained; The actual oscillation period is calculated according to the actual time difference.

7. The swing reactance parameter calculation device applied to PSS according to claim 5, characterized in that: The reactance calculation unit is specifically used for: calculating an actual oscillation frequency based on the actual oscillation period; The actual oscillation frequency is substituted into a preset swing reactance formula to calculate the actual swing reactance, thereby obtaining the actual swing reactance value.

8. The swing reactance parameter calculation device applied to PSS according to claim 5, characterized in that: Also includes: A speed calculation unit, used for calculating the speed of the computer group according to the selected actual swing reactance value; a change calculation unit, used for inputting the unit speed and electromagnetic power into the target PSS to calculate the acceleration power change; The signal generating unit is used to process the acceleration power variation through the lead-lag link and the limit link to generate an additional excitation control signal.

9. A swing reactance parameter calculation device for PSS, characterized in that: The device comprises a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the swing reactance parameter calculation method applied to PSS according to any one of claims 1 to 4 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the swing reactance parameter calculation method applied to PSS according to any one of claims 1 to 4.

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