Method for quickly optimizing Anti-regulation effect of power system stabilizer

Abstract

A method for quickly optimizing an anti-regulation effect of a power system stabilizer, comprising: Step 1, deducing specific parameters affecting an anti-regulation effect of a power system stabilizer; Step 2, dividing the specific parameters affecting the anti-regulation effect of the power system stabilizer into a constant portion and an adjustable portion; and Step 3, with respect to the adjustable portion of the specific parameters affecting the anti-regulation effect of the power system stabilizer, performing a generator terminal voltage step; on the basis of whether the numerical value of a set node after the step is within a set range, determining whether there is anti-regulation in two channels, namely the rotation speed w and the power p, of the stabilizer; and, if there is anti-regulation, adjusting the parameters of the adjustable portion to reduce the numerical value of the set node to the set range, thereby eliminating the anti-regulation. On the basis of a step test, it is directly determined that whether parameters of two channels are reasonable, so as to quickly narrow the range of parameters requiring adjustment, thereby achieving quick optimization of an anti-regulation effect of power system stabilizers.

Description

A method for rapidly optimizing the reverse regulation effect of power system stabilizers Technical Field

[0001] The present invention relates to the technical field of power system equipment optimization, and in particular to a method for rapidly optimizing the reverse regulation effect of a power system stabilizer. Background Art

[0002] A power system stabilizer is an additional control device that serves as an input to the excitation system PID controller. As shown in Figure 1, it uses an automatic voltage regulator (AVR) to control synchronous motor excitation and suppress power system oscillations. The input variable can be a single variable such as speed, frequency, or power, or a combination of these variables.

[0003] Back-regulation: When the output power of the prime mover increases (or decreases), the magnetic field voltage, synchronous motor voltage and reactive power decrease (or increase) accordingly due to the regulation of the power system stabilizer.

[0004] The purpose of the reverse test is to check whether the fluctuation of the generator reactive power and generator voltage is within the permitted range when the prime mover has the maximum output speed.

[0005] Requirements for reverse regulation test: the change in reactive power is less than 20% of the rated reactive power, and the change in terminal voltage is less than 2% of the rated voltage.

[0006] Numerous excitation system manufacturers, each with varying technical capabilities, have diverse implementation methods for even standard power system stabilizer models. Power system stabilizer model hardware and software are relatively fixed, making it difficult for excitation system manufacturers to address the power system stabilizer's reverse regulation effects.

[0007] Therefore, there are currently two main ways to solve the reverse regulation effect of the power system stabilizer:

[0008] 1. Change the active power adjustment speed: The faster the active power adjustment speed, the greater the reverse adjustment of the power system stabilizer will be. Conversely, the slower the active power adjustment speed, the smaller the reverse adjustment of the power system stabilizer will be. By changing the active power adjustment speed, the reverse adjustment effect of the power system stabilizer can be reduced;

[0009] 2. Adjust the power system stabilizer parameters: There are many parameters that affect the anti-regulation effect of the power system stabilizer. By adjusting the Ks1, Tw1, Tw2, Tw3, Tw4, Ks2, T7, Ks3, T8, T9, M and N parameters, the anti-regulation effect of the power system stabilizer can be reduced.

[0010] Changing the active power regulation speed can affect the effectiveness of the power system stabilizer's reverse regulation, but the primary underlying issue lies in the power system stabilizer's parameters. In actual testing, manual adjustment of the active power regulation speed is rarely performed. The speed varies from person to person, making it difficult to standardize the speed for each increase and decrease. Therefore, active power is often adjusted through monitoring commands. Once the monitoring system selects the fastest possible speed, the active power regulation speed remains fixed. Therefore, adjusting the power system stabilizer's parameters is crucial. Numerous parameters can influence the effectiveness of the power system stabilizer's reverse regulation, leading to the need for a method that can quickly identify the root cause of the power system stabilizer's reverse regulation, narrow the range of parameters requiring modification, and thus improve testing efficiency.

[0011] Summary of the Invention

[0012] The technical problem to be solved by the present invention is to provide a method for quickly optimizing the counter-regulation effect of the power system stabilizer, derive the parameters that specifically affect the counter-regulation effect of the power system stabilizer, and analyze the conventional solution methods for the parameters that affect the counter-regulation effect of the power system stabilizer, and finally form a method for quickly optimizing the counter-regulation effect of the power system stabilizer with low difficulty and high efficiency.

[0013] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0014] A method for rapidly optimizing the reverse regulation effect of a power system stabilizer comprises the following steps:

[0015] Step 1: Analyze the parameters of each link of the power system stabilizer to derive the specific parameters that affect the reverse adjustment effect of the power system stabilizer;

[0016] Step 2: Divide the specific parameters that affect the reverse regulation effect of the power system stabilizer into fixed parts and adjustable parts;

[0017] Step 3: For the adjustable part of the specific parameters that affect the counter-regulation effect of the power system stabilizer, by performing a step of the terminal voltage, the value of the setting node after the step is checked to see if it is within the set range, and then determine whether there is counter-regulation in the two channels of the stabilizer speed w and power p. If there is counter-regulation, the adjustable parameters are adjusted to reduce the value of the setting node to within the set range, so that the counter-regulation disappears.

[0018] The setting node in the above Step 3 is the joint action node of the stabilizer speed w and power p, that is, the first signal superposition point (7).

[0019] The above-mentioned power system stabilizer PID control model structure is that the speed channel w input value V1 passes through the first isolation link and the second isolation link in sequence and then acts on the first signal superposition point, while the power channel p input value V2 passes through the third isolation link, the fourth isolation link, the inertia link and the power and speed conversion link in sequence and then acts on the first signal superposition point, the first signal superposition point acts on the second signal superposition point through the low-pass filter link, the inertia link also acts on the second signal superposition point, and the output end of the second signal superposition point passes through the proportional amplification link, the first lead-lag link, the second lead-lag link and the third lead-lag link in sequence and then outputs.

[0020] The output end of the third lead-lag link is output after passing through the automatic switching switch.

[0021] The parameters of the first interval link are The second interval parameter is The parameters of the third interval link are The fourth interval parameter is The inertia link parameters are The power and speed conversion link parameter is Ks3, and the low-pass filter link parameter is The parameter of the proportional amplification link is Ks1, and the parameter of the first lead-lag link is The parameters of the second lead-lag link are The parameters of the third lead-lag link are

[0022] The present invention provides a method for rapidly optimizing the reverse regulation effect of a power system stabilizer. Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] 1. This method reduces the range of reverse adjustment parameters in the power system stabilizer parameter setting test, improves the efficiency of the power system stabilizer parameter setting test, and saves the power system stabilizer test cost;

[0024] 2. This method optimizes the fixed values ​​of the reverse adjustment parameters in the power system stabilizer parameter setting test, improves the reverse adjustment effect of the power system stabilizer, and improves the overall effect of the power system stabilizer;

[0025] 3. This method shortens the power system stabilizer parameter setting test time, reduces the power generation cost of the power plant power system stabilizer parameter setting test, and increases the commercial power generation time of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples:

[0027] FIG1 is a diagram of a PID control model of an existing power system stabilizer;

[0028] Figure 2 is a diagram of the 1A type PID control model of the power system stabilizer;

[0029] Figure 3 is a diagram of the 2A type PID control model of the power system stabilizer;

[0030] Figure 4 is a diagram of the 2B type PID control model of the power system stabilizer;

[0031] FIG5 is a diagram of a PID control model of a power system stabilizer according to the present invention;

[0032] FIG6 is a diagram showing the effect of reverse adjustment when the method is not implemented in an embodiment of the present invention;

[0033] FIG7 is a diagram showing the effect of the reverse adjustment during the test process according to an embodiment of the present invention;

[0034] FIG8 is a diagram showing the reverse adjustment effect of the unit after using this method in an embodiment of the present invention.

[0035] Among them: the first isolation link 1, the second isolation link 2, the third isolation link 3, the fourth isolation link 4, the inertia link 5, the power and speed conversion link 6, the first signal superposition point 7, the low-pass filter link 8, the second signal superposition point 9, the proportional amplification link 10, the first lead-lag link 11, the second lead-lag link 12, the third lead-lag link 13, and the automatic on / off switch 14. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0037] A method for rapidly optimizing the reverse regulation effect of a power system stabilizer comprises the following steps:

[0038] Step 1: Analyze the parameters of each link of the power system stabilizer to derive the specific parameters that affect the reverse adjustment effect of the power system stabilizer;

[0039] Step 2: Divide the specific parameters that affect the reverse regulation effect of the power system stabilizer into fixed parts and adjustable parts;

[0040] Step 3: For the adjustable part of the specific parameters that affect the counter-regulation effect of the power system stabilizer, by performing a step of the terminal voltage, the value of the setting node after the step is checked to see if it is within the set range, and then determine whether there is counter-regulation in the two channels of the stabilizer speed w and power p. If there is counter-regulation, the adjustable parameters are adjusted to reduce the value of the setting node to within the set range, so that the counter-regulation disappears.

[0041] The setting node in the above Step 3 is the joint action node of the stabilizer speed w and power p, that is, the first signal superposition point 7.

[0042] The above-mentioned power system stabilizer PID control model structure is that the speed channel w input value V1 passes through the first isolation link 1 and the second isolation link 2 in sequence and then acts on the first signal superposition point 7, while the power channel p input value V2 passes through the third isolation link 3, the fourth isolation link 4, the inertia link 5 and the power and speed conversion link 6 in sequence and then acts on the first signal superposition point 7, the first signal superposition point 7 acts on the second signal superposition point 9 through the low-pass filter link 8, the inertia link 5 also acts on the second signal superposition point 9, and the output end of the second signal superposition point 9 passes through the proportional amplification link 10, the first lead-lag link 11, the second lead-lag link 12 and the third lead-lag link 13 in sequence and then outputs.

[0043] The output end of the third lead-lag link 13 is output through the automatic switching switch 14.

[0044] The parameters of the first interval link 1 are The second interval link 2 parameter is The third interval parameter 3 is The fourth interval link 4 parameter is The parameters of inertia link 5 are The parameter of power and speed conversion link 6 is Ks3, and the parameter of low-pass filter link 8 is The parameter of the proportional amplification link 10 is Ks1, and the parameter of the first lead-lag link 11 is The parameters of the second lead-lag link 12 are The parameters of the third lead-lag link 13 are

[0045] Example:

[0046] Unit 1 of a power plant, rated capacity: 22.2MVA, rated active power: 20MW, rated reactive power 9.63MVar: rated stator voltage: 10.5kV, rated speed: 75r / min, generator and turbine flywheel torque GD2: 3400t.m 2 , inertia time constant Tj: 2.36s. The PSS parameters set at the beginning of the test are:

[0047] Tw1=Tw2=Tw3=T7=5s, Tw4=0s; where 0 represents passage, T1=0.13s, T2=0.02s, T3=0.1s, T4=0.02s, T5(T10)=T6(T11)=0s, T8=0.6s, T9=0.12s, Ks1=6, Ks2=2.12, Ks3=1, M=5, N=1.

[0048] The effect of this set of parameter back-adjustment tests is very poor, and the specific data are shown in Figure 6 and Table 1.

[0049] In Figure 6: UAB is the generator terminal voltage, that is, the line voltage; UFD is the excitation voltage; IFD is the excitation current; P2L is the active power; Q2L is the reactive power.

[0050] Table 1 Reactive power data of reverse regulation test

[0051] During the process, by recording the PSS_6 waveform, it was found that the amplitude was 0.4, indicating that the w and P channels had outputs, and the main range causing the counter-regulation had not been locked at this time; by continuously modifying the internal channel coefficients of the regulator, the PSS_6 waveform was continued to be recorded until it was found that the minimum amplitude was 0.08. No matter how the parameters were modified, this output could not have a smaller value; at this time, it can be considered that the PSS_6 amplitude of 0.08 is the 0 value when the w and P channels have no output.

[0052] At this point, the counter-adjustment test was continued and it was found that the counter-adjustment test effect was still not good enough. The specific data are shown in Figure 7 and Table 2.

[0053] Table 2 Reactive power data of reverse regulation test

[0054] By using the method of the present invention, since parameters Tw1, Tw2, Tw3, Tw4, and T7 are located in the w and P channels, and the w and P channels output 0, it can be determined that the settings for Tw1, Tw2, Tw3, Tw4, and T7 are correct. Since Ks2 = T7 / Tj, with Tj being a fixed value, the Ks2 setting is correct. Further experiments by adjusting the Ks1 value revealed that it is not Ks1 that causes significant counter-tuning changes. Therefore, the counter-tuning is locked to T8, T9, M, and N, that is, the low-pass filter. A set of PSS parameters with an ideal counter-tuning effect can be quickly obtained:

[0055] Tw1=Tw2=Tw3=T7=5s, Tw4=0s (0 indicates passage), T1=0.13s, T2=0.02s, T3=0.1s, T4=0.02s, T5(T10)=T6(T11)=0s, T8=0.3s, T9=0.1s, Ks1=6, Ks2=2.12, Ks3=1, M=3, N=1.

[0056] The counter-adjustment test using the new parameters produced very ideal results. The specific data are shown in Figure 8 and Table 3.

[0057] Table 3 Reactive power data of reverse regulation test

[0058] In existing power system applications, the reasons why the power system stabilizer reverse adjustment cannot fire protection are:

[0059] 1. Power system stabilizer 1A, as shown in Figure 2, has a natural reverse regulation:

[0060] The 1A model of the power system stabilizer, a single-input power system stabilizer that uses electric power as its input signal, can cause severe reactive power back-regulation when adjusting active power. This is because when the generator's active power increases or decreases normally, the fluctuations in active power are not low-frequency oscillations. However, the 1A model does not collect speed signals and cannot distinguish whether the active power changes are caused by the system or the prime mover. In this case, the 1A model's output is still superimposed on the generator-side voltage reference, which inevitably leads to reactive power back-regulation.

[0061] 2. Power system stabilizer 2A / 2B, as shown in Figures 3 and 4, has no reverse regulation in theory, but in reality:

[0062] The 2A / 2B model of the power system stabilizer (PSS) uses two inputs, one for W and the other for P. Its principle is to use W and P to calculate the generator's mechanical power (△Pm) and electromagnetic power (△Pe). Subtracting these two yields the generator's acceleration power (△Pa). This way, when the unit increases or decreases load in one direction, the acceleration power is zero, and the power system stabilizer is inoperative, meaning no reactive reverse regulation occurs. While the 2A / 2B model can theoretically effectively suppress reverse regulation, it still occurs in practice for three main reasons:

[0063] 1) Different excitation system manufacturers handle the speed W differently. Some manufacturers perform attenuation processing on it within their programs, resulting in inaccurate sampling of the speed W signal;

[0064] 2) During the test, the testers set the power system stabilizer parameters differently due to their own technical level and test experience limitations;

[0065] 3) During the test, the maximum output change rate of the prime mover was not understood accurately, which affected the change rate of the active power regulation:

[0066] ① The test personnel have limited knowledge of the maximum output change speed of the prime mover; ② Due to practical conditions, it is difficult to test the maximum output change speed of the prime mover. Usually, the prime mover output is adjusted at the normal operating speed for testing, and the waveform of the unit's reactive power reverse adjustment is recorded, which obviously cannot effectively verify the rationality of the power system stabilizer parameters.

[0067] Under existing technical conditions, power system stabilizers have the following shortcomings:

[0068] 1. Changing the active power regulation speed to solve the reverse regulation effect of the power system stabilizer:

[0069] 1) After changing the active power regulation speed, the requirements of the test guide for reverse regulation test may not be met;

[0070] 2) To change the active power regulation speed, it is necessary to change the parameters of the monitoring system or the speed regulator;

[0071] 3) The parameters of the monitoring system and the speed regulator are often not allowed to be modified or cannot be modified on site;

[0072] 4) Manually changing the active power regulation speed will cause the adjustment speed to vary from person to person, and it is difficult to unify the rising and falling speeds.

[0073] 2. Adjust the power system stabilizer parameters to solve the power system stabilizer counter-regulation effect:

[0074] 1) There are many parameters that affect the counter-regulation effect of the power system stabilizer, and there are many combinations of parameters to be adjusted;

[0075] 2) To determine which parameter has the greatest impact on the power system stabilizer's reverse regulation effect, repeated experiments are required;

[0076] 3) Due to the limitations of the technical level and experimental experience of the test personnel, they may not have found a solution to the counter-adjustment;

[0077] 4) Adjusting the parameters that affect the counter-regulation effect of the power system stabilizer may affect the effects of other functions of the power system stabilizer.

[0078] Because the 1A model of the power system stabilizer inherently has reverse regulation, it is rarely used in excitation systems on the market. Some older, smaller power plants may still have some of these models, but these will be gradually upgraded and renovated to meet grid requirements. Therefore, this article will only discuss methods for quickly optimizing the reverse regulation effect of the 2A / 2B model of the power system stabilizer:

[0079] 1. By analyzing the role of parameters in each link of the power system stabilizer, the parameters that specifically affect the reverse adjustment effect of the power system stabilizer are derived.

[0080] There are many parameters that affect the back-regulation effect of the power system stabilizer. The back-regulation effect of the power system stabilizer can be reduced by adjusting the parameters Ks1, Tw1, Tw2, Tw3, Tw4, Ks2, T7, Ks3, T8, T9, M and N. Ks1 is the gain of the power system stabilizer, which is the easiest to test. The larger Ks1 is, the larger the back-regulation is, and the smaller Ks1 is, the smaller the back-regulation is. Tw1, Tw2, Tw3, and Tw4 are the DC blocking time constants. The smaller the DC blocking time constant is, the smaller the back-regulation is, and vice versa. Ks2 is the power gain, and its value is equal to T7 / Tj. The larger Ks2 is, the larger the back-regulation is, and the smaller Ks2 is, the smaller the back-regulation is. T7 is the power integration time constant. Under normal circumstances, T7 = Tw1 = Tw2 = Tw3. Tj is the generator inertia time constant, which is determined according to the rotational inertia of the generator and shaft system or the flywheel torque. The specific formula is: Tj = 2.74*n 2 *GD 2 / 1000Pn; Ks3 power and speed conversion constant, less than 1 anti-modulation large, equal to 1 anti-modulation small; T8 and T9 are ramp functions, and form a combination with M and N, which is a low-pass filter link; the anti-anti-modulation mechanism of the 2A / 2B model mainly depends on the similarity between the input and output signals of the ramp function. When the entire link is equal to 1, that is, T8=T9*M and N=1, the similarity is the highest and the anti-anti-modulation ability is the strongest; otherwise, the anti-anti-modulation ability is weak.

[0081] 2. Analyze the conventional solutions to the parameters that affect the counter-regulation effect of the power system stabilizer and analyze the shortcomings of the solutions.

[0082] The above analysis shows that many parameters affect the back-regulation effect of power system stabilizers, and each of these parameters influences each other. Selecting a set of parameters that minimizes the back-regulation effect while ensuring the damping ratio meets regulatory requirements is a very difficult task. Adjusting parameters often requires adjusting multiple parameters simultaneously to achieve the desired effect. Therefore, the only approach is trial and error: adjusting parameters first, then testing, and only adjusting parameters if the back-regulation effect is unsatisfactory. This requires constant parameter combination testing, resulting in a massive workload and low efficiency.

[0083] 3. Aiming at the shortcomings of the solution, a method with low difficulty and high efficiency to quickly optimize the reverse adjustment effect of the power system stabilizer is refined.

[0084] Parameters T8, T9, M, and N are a combination and are often relatively fixed, that is, T8 = T9 * M and N = 1; Ks1 can also be fixed at a certain value according to the damping ratio; as long as the generator-related design parameters are accurate, then Ks2 is a fixed value; Ks3 is also a fixed value, and all default to 1; then the remaining parameters are Tw1, Tw2, Tw3, Tw4, and T7, which are just distributed in the two channels of w and P.

[0085] At this point, if there is a method to quickly determine whether the W and P channels have reverse regulation, the test efficiency will be greatly improved. The specific method is as follows: While maintaining the active power and reactive power unchanged, the generator-side voltage is stepped by 2%-4%, and the PSS_6 waveform in Figure 5 is recorded in real time. Because the active power on the system side does not change at this time, the power system stabilizer should not output any signal after the voltage step, that is, the PSS_6 value should be 0, indicating that the W and P channels have no output and no reverse regulation. If the PSS_6 value is not 0, it indicates that the W and P channels have output after superposition, which will definitely cause reverse regulation. In other words, either the parameters of the two channels are unreasonable or the channel coefficients of the two channels are unreasonable. Only by adjusting the PSS_6 value to close to 0 after the step can the power system stabilizer be guaranteed to have no reverse regulation. Through the step test method, the rationality of the parameters of the two channels can be directly determined, and the range of adjustment parameters can be quickly narrowed, thereby achieving rapid optimization of the reverse regulation effect of the power system stabilizer.

Claims

1. A method for rapidly optimizing the reverse regulation effect of a power system stabilizer, characterized in that: The steps include: Step 1: Analyze the parameters in each link of the power system stabilizer to derive the specific parameters that affect the reverse adjustment effect of the power system stabilizer; Step 2, divide the specific parameters that affect the reverse adjustment effect of the power system stabilizer into a fixed part and an adjustable part; Step 3: For the adjustable part of the specific parameters that affect the reverse adjustment effect of the power system stabilizer, a step is made in the machine-end voltage to determine whether the value of the set node after the step is within the set range, and then determine whether there is reverse adjustment in the two channels of the stabilizer speed w and power p. If there is reverse adjustment, the adjustable parameters are adjusted to reduce the value of the set node to within the set range, so that the reverse adjustment disappears.

2. A method for rapidly optimizing the reverse regulation effect of a power system stabilizer according to claim 1, characterized in that: The setting node in the Step 3 is the joint action node of the stabilizer speed w and power p, that is, the first signal superposition point (7).

3. A method for rapidly optimizing the reverse regulation effect of a power system stabilizer according to claim 2, characterized in that: The structure of the PID control model of the power system stabilizer is as follows: the speed channel w input value V1 passes through the first isolation link (1) and the second isolation link (2) in sequence and then acts on the first signal superposition point (7); the power channel p input value V2 passes through the third isolation link (3), the fourth isolation link (4), the inertia link (5) and the power and speed conversion link (6) in sequence and then acts on the first signal superposition point (7); the first signal superposition point (7) acts on the second signal superposition point (9) through the low-pass filter link (8); the inertia link (5) also acts on the second signal superposition point (9); the output end of the second signal superposition point (9) passes through the proportional amplification link (10), the first lead-lag link (11), the second lead-lag link (12) and the third lead-lag link (13) in sequence and then outputs.

4. A method for rapidly optimizing the reverse regulation effect of a power system stabilizer according to claim 3, characterized in that: The output end of the third lead-lag link (13) is outputted through the automatic throw-in / out switch (14).

5. A method for rapidly optimizing the reverse regulation effect of a power system stabilizer according to claim 3, characterized in that: The parameters of the first interval link (1) are The parameters of the second interval (2) are The parameters of the third interval (3) are The parameters of the fourth interval link (4) are The parameters of the inertia link (5) are The parameter of the power and speed conversion link (6) is Ks3, and the parameter of the low-pass filter link (8) is The parameter of the proportional amplification link (10) is Ks1, and the parameter of the first lead-lag link (11) is The parameters of the second lead-lag link (12) are The parameters of the third lead-lag link (13) are

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