Active damping parameter design method and device for network-constructed flexible direct current converter station

Abstract

This invention discloses a method and apparatus for designing active damping parameters for a grid-connected flexible DC converter station. The method includes: obtaining the negative sequence impedance based on the voltage and current at the grid connection point; obtaining the complex form of the active damping impedance and the original impedance of the converter station based on the negative sequence impedance; constructing a function of the real part of the impedance with respect to frequency based on the active damping impedance and the original impedance of the converter station, and obtaining a first function and a second function respectively; the damping compensation controller includes a bandpass filter, a gain resistance, and a compensation gain stage; obtaining the expression for the negative sequence equivalent resistance on the AC side of the converter station based on the first function and the second function; obtaining the parameter range of the damping compensation controller based on the expression for the negative sequence equivalent resistance and the integral area method; and selecting the parameters of the damping compensation controller based on the parameter range.

Description

Technical Field

[0001] This invention relates to the field of power electronics, and in particular to a method and apparatus for designing active damping parameters for grid-type flexible DC converter stations. Background Technology

[0002] With the rapid development of large-scale grid connection of new energy sources and inter-regional power grid interconnection, grid-type MMC (modular multilevel converter) flexible DC converter stations based on voltage single closed-loop control have become an important research direction due to their ability to provide stable voltage support. However, grid-type control still faces broadband oscillation problems similar to those of grid-connected systems, especially in weak grid environments with a high proportion of power electronic equipment, where the risk of low-frequency oscillations is more prominent. To suppress low-frequency oscillations, active damping technology has been widely introduced into grid-type control.

[0003] Currently, common active damping control typically incorporates virtual impedance or digital filters into the control loop. The effectiveness of this technique heavily relies on the rational design of key parameters such as center frequency, bandwidth, and gain. Existing techniques often depend on engineers' experience for parameter design, evaluating damping effects through extensive time-domain simulations. This method is inefficient and struggles to guarantee optimal or robust damping performance under all potential operating conditions. Furthermore, the lack of a clear theoretical link between parameters and system stability indicators leads to significant uncertainty in the design process. Simultaneously, existing methods typically design only a fixed set of damping parameters. However, the system's small-signal model drifts with the operating point, and a fixed damper may be ineffective under certain conditions, failing to achieve oscillation suppression across the entire operating range, especially in the low-frequency range.

[0004] Therefore, a new technical solution is urgently needed to address the technical problem of how to improve the low-frequency damping performance of grid-type MMC flexible DC converter stations based on voltage single closed-loop control. Summary of the Invention

[0005] This invention provides a method and apparatus for designing active damping parameters for grid-type flexible DC converter stations, in order to solve the technical problem of how to improve the low-frequency damping performance of grid-type MMC flexible DC converter stations based on voltage single closed-loop control.

[0006] To achieve the above objectives, this invention provides a method for designing active damping parameters for grid-type flexible DC converter stations, comprising:

[0007] The negative sequence impedance is obtained from the voltage and current at the grid connection point; the complex form of the active damping impedance and the original impedance of the converter station are obtained from the negative sequence impedance; the real part of the impedance is constructed as a function of frequency variation based on the active damping impedance and the original impedance of the converter station, and the first function and the second function are obtained respectively; the damping compensation controller includes a bandpass filter, a gain resistance, and a compensation gain stage; the expression for the negative sequence equivalent resistance on the AC side of the converter station is obtained from the first function and the second function; the parameter range of the damping compensation controller is obtained from the expression for the negative sequence equivalent resistance combined with the integral area method; the parameters of the damping compensation controller are selected based on the parameter range.

[0008] Preferably, the negative sequence impedance is obtained based on the voltage and current at the grid connection point, including:

[0009] The relationship between voltage and current at the grid connection point of the converter station is obtained by using a linearization method, thus yielding the negative sequence impedance. :

[0010] ;

[0011] in, It is a voltage loop PI controller; and These are the proportional and integral coefficients of the voltage loop PI controller, respectively. For the Laplace operator; The power system angular frequency; For damping compensation controllers, in the initial state ; This refers to the number of MMC bridge arm sub-modules. This represents the steady-state value of the MMC DC voltage. This refers to the steady-state DC component of the capacitor voltage of the bridge arm submodule; The equivalent inductance between the AC side and the PCC point of the grid-type flexible DC converter station; The equivalent resistance between the AC side and the PCC point of a grid-type flexible DC converter station; This is a virtual part unit.

[0012] Preferably, based on the active damping impedance and the original impedance of the converter station, combined with the damping compensation controller, a function of the real part of the impedance with respect to frequency is constructed, resulting in the first function and the second function, which include:

[0013] In the bandpass filter of the damping compensation controller, a pre-selected filter is used for DC filtering;

[0014] make , , Angular frequency, For the target frequency band range, substitute the expression of the damping compensation controller into the expression of the active damping impedance and the expression of the original impedance of the converter station to obtain the first expression and the second expression respectively; extract the real parts of the first expression and the second expression to obtain the first real part and the second real part; and obtain the first function and the second function based on the first real part and the second real part.

[0015] Preferred options also include:

[0016] In the bandpass filter of the damping compensation controller, a second-order bandpass filter is used for DC filtering. Represented as:

[0017] ;

[0018] in, , and These represent the gain, resistance, damping ratio, and undamped oscillation angular frequency of a second-order bandpass filter, respectively. This is the undamped oscillation frequency.

[0019] Preferably, the negative-sequence equivalent resistance expression for the AC side of the converter station is obtained based on the first function and the second function; the parameter range of the damping compensation controller is obtained by combining the negative-sequence equivalent resistance expression with the integral area method, including:

[0020] Add the first and second functions to obtain the negative-sequence equivalent resistance expression; set the negative-sequence equivalent resistance expression to be greater than 0, and classify the terms in the negative-sequence equivalent resistance expression according to whether they include the parameters of the damping compensation controller, to obtain the third and fourth functions respectively; perform monotonicity analysis based on the combination of the third and fourth functions, and obtain the parameter range of the damping compensation controller by combining the integral area principle.

[0021] Preferably, based on the monotonicity analysis performed using the third and fourth functions, and combined with the integral area principle, the parameter range of the damping compensation controller is obtained as follows:

[0022] Analyze the monotonicity of the third function to obtain the range in which the third function is greater than 0 within the target frequency band, thus obtaining the first parameter range; analyze the monotonicity of the fourth function to obtain the frequency band in which the fourth function is less than 0, thus obtaining the first frequency band; perform definite integrals on the third and fourth functions within the first frequency band to obtain the first area and the second area enclosing the coordinate axes of the third and fourth functions, respectively; set the first area greater than the second area to obtain the second parameter range; take the intersection of the first parameter range and the second parameter range to obtain the parameter range of the damping compensation controller.

[0023] The present invention also provides an active damping parameter design device for a grid-type flexible DC converter station, which is used in the method of the present invention. The device includes a first module, a second module, a third module and a fourth module.

[0024] The first module is used to obtain the negative sequence impedance based on the voltage and current at the grid connection point.

[0025] The second module is used to obtain the complex form of the active damping impedance and the original impedance of the converter station based on the negative sequence impedance; based on the active damping impedance and the original impedance of the converter station, a function of the real part of the impedance with respect to frequency is constructed in combination with the damping compensation controller, and the first function and the second function are obtained respectively; the damping compensation controller includes a bandpass filter, a gain resistance value and a gain compensation stage in sequence.

[0026] The third module is used to obtain the negative-sequence equivalent resistance expression of the AC side of the converter station based on the first and second functions; and to obtain the parameter range of the damping compensation controller based on the negative-sequence equivalent resistance expression combined with the integral area method.

[0027] The fourth module is used to select the parameters of the damping compensation controller according to the parameter range.

[0028] The present invention has the following beneficial effects:

[0029] This invention presents an active damping parameter design method for grid-type flexible DC converter stations. By separating positive and negative sequence impedances, characterizing negative damping using the impedance integral area, and compensating for the negative damping integral area using a damping compensation controller, the method achieves parameter design. This method improves the damping performance of flexible DC transmission systems in the low-frequency range, reduces the risk of low-frequency oscillations when grid-type flexible DC converter stations are connected to the grid, enhances the stability of grid-type flexible DC transmission systems, and enables stable operation of grid-type flexible DC converter stations under a wide range of AC system operating conditions. This method requires no additional parameter debugging steps, has a simple algorithm, is easy to implement, does not affect dynamic and transient operating characteristics, does not change the original control and protection system parameters, and requires no additional hardware equipment. It effectively reduces the risk of low-frequency instability, and the designed parameters have strong robustness.

[0030] The active damping parameter design device for grid-type flexible DC converter stations of the present invention, when used in the method of the present invention, has the same beneficial effects as the method of the present invention.

[0031] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the main circuit structure of a grid-type MMC flexible DC converter station according to a preferred embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the method flow of a preferred embodiment of the present invention.

[0035] Figure 3 This is a damping compensation controller according to a preferred embodiment of the present invention. A schematic diagram of the control process.

[0036] Figure 4 This is a schematic diagram of the impedance characteristics obtained after following the method of the present invention in a preferred embodiment. Detailed Implementation

[0037] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] The main circuit structure of the grid-type MMC flexible DC converter station of the preferred embodiment of the present invention is shown below. Figure 1 ;in, The phase voltage amplitude at the PCC point (point of common coupling, grid connection point); This represents the phase difference between the voltage at point PCC and the equivalent power source of the grid. and This is the equivalent resistance and inductance of the converter transformer; The current flowing into the converter station at point PCC; and Inject the active and reactive power of the converter station into the PCC point; and These are DC voltage and DC current, respectively.

[0039] See Figure 2 In a preferred embodiment of the present invention, an active damping parameter design method for a grid-type flexible DC converter station is provided, comprising:

[0040] Q1. Obtain the negative sequence impedance based on the voltage and current at the grid connection point. Q1 specifically includes:

[0041] The relationship between voltage and current at the grid connection point of the converter station is obtained by using a linearization method, thus yielding the negative sequence impedance. :

[0042] ;

[0043] in, It is a voltage loop PI controller; and These are the proportional and integral coefficients of the voltage loop PI controller, respectively. For the Laplace operator; The power system angular frequency; For damping compensation controllers, in the initial state ; This refers to the number of MMC bridge arm sub-modules. This represents the steady-state value of the MMC DC voltage. This refers to the steady-state DC component of the capacitor voltage of the bridge arm submodule; The equivalent inductance between the AC side and the PCC point of the grid-type flexible DC converter station; The equivalent resistance between the AC side and the PCC point of a grid-type flexible DC converter station; This is a virtual part unit.

[0044] In a preferred embodiment of the present invention, based on the operating principle of the converter station, the relationship between voltage and current at the PCC point is calculated using a linearization method. This allows for a clear understanding of the key influencing factors and their influence patterns on the converter station impedance, laying a theoretical foundation for the development of a low-frequency band negative damping compensation controller.

[0045] Q2. Obtain the complex form of the active damping impedance and the original impedance of the converter station based on the negative sequence impedance. Using the active damping impedance and the original impedance of the converter station, construct a function of the real part of the impedance with respect to frequency using a damping compensation controller, obtaining the first function and the second function respectively. The damping compensation controller sequentially includes a bandpass filter, a gain resistor, and a gain compensation stage. Q2 specifically includes:

[0046] Based on the converter station control structure and the installation location of the damping compensation controller, the negative sequence impedance is decomposed to obtain the active damping impedance and the original impedance of the converter station:

[0047] ;

[0048] in, Indicates the original impedance of the converter station; This represents the active damping impedance. By rationalizing and simplifying the denominator based on the active damping impedance and the original impedance of the converter station, we obtain the complex forms of the active damping impedance and the original impedance of the converter station.

[0049] In the bandpass filter of the damping compensation controller, a pre-selected filter is used for DC filtering.

[0050] In low-frequency damping compensation controllers, there are various options for DC filtering, such as first-order high-pass filters, second-order high-pass filters, second-order band-pass filters, and third-order band-pass filters, which can be selected according to actual needs. In a preferred embodiment of the present invention, a second-order band-pass filter is used for DC filtering in the damping compensation controller. Represented as:

[0051] ;

[0052] in, , and These represent the gain, resistance, damping ratio, and undamped oscillation angular frequency of a second-order bandpass filter, respectively. This is the undamped oscillation frequency.

[0053] Damping Compensation Controller See the control process Figure 3 The dq-axis component of the PCC point current containing oscillating components and After passing through a bandpass filter, the DC component is filtered out and the compensation passband is limited. Then, after passing through a gain resistor, a compensation voltage is generated. After passing through a compensation gain, the negative effects caused by the internal dynamic characteristics of the MMC are offset, and finally, an oscillation compensation voltage is generated. and And then sent to the modulation process.

[0054] In a preferred embodiment of the present invention, let , , Angular frequency, For the target frequency range [0Hz, 200Hz], substitute the expression of the damping compensation controller into the expressions of the active damping impedance and the original impedance of the converter station to obtain the first expression and the second expression respectively; extract the real parts of the first and second expressions to obtain the first real part and the second real part; based on the first real part and the second real part, obtain the first function and the second function. Specifically, this includes:

[0055] make , Damping compensation controller Expand the expression:

[0056] ;

[0057] Substituting the above equation into the complex form of the active damping impedance and the original impedance of the converter station, we obtain the first and second expressions, which are expressed as follows:

[0058] ;

[0059] Extract the real parts of the first and second expressions to obtain the first real part. Second real part The order is represented as:

[0060] ;

[0061] Substitution We obtain the functional relationship between the real part of the impedance and the frequency change, namely the first function and the second function, which are expressed as follows:

[0062] ;

[0063] Q3. Obtain the expression for the negative-sequence equivalent resistance on the AC side of the converter station based on the first and second functions; obtain the parameter range of the damping compensation controller based on the expression for the negative-sequence equivalent resistance combined with the integral area method. Q3 specifically includes:

[0064] Add the first and second functions to obtain the negative-sequence equivalent resistance expression; set the negative-sequence equivalent resistance expression to be greater than 0, and classify the terms in the negative-sequence equivalent resistance expression according to whether they include the parameters of the damping compensation controller, to obtain the third and fourth functions respectively; perform monotonicity analysis based on the combination of the third and fourth functions, and obtain the parameter range of the damping compensation controller by combining the integral area principle.

[0065] In a preferred embodiment of the present invention, the first function and the second function are added to obtain the expression for the negative-sequence equivalent resistance; to ensure that the converter station has no negative damping in the low-frequency band, the expression for the negative-sequence equivalent resistance is set to be greater than 0, and the inequality is simplified to obtain:

[0066] ;

[0067] in, , , , , and The coefficients of the terms after simplifying the inequality are represented, including:

[0068] ;

[0069] In a preferred embodiment of the present invention, the terms in the negative-sequence equivalent resistance expression are categorized according to whether they include parameters of the damping compensation controller. For the above inequalities, only the fifth and fourth power coefficients do not contain parameters of the damping compensation controller, thus yielding two univariate polynomial functions and a third function, respectively. and the fourth function ,include:

[0070] ;

[0071] In a preferred embodiment of the present invention, the parameter range of the damping compensation controller is obtained by combining the third and fourth functions for monotonicity analysis and by incorporating the integral area principle, including:

[0072] Analyze the monotonicity of the third function to obtain the range within which the third function is greater than 0 in the target frequency band, and thus obtain the range of the first parameter. .

[0073] Analyzing the monotonicity of the fourth function, we obtain the frequency bands where the fourth function is less than 0, thus obtaining the first frequency band. Within the first frequency band, definite integrals are performed on the third and fourth functions to obtain the areas enclosed by the third and fourth functions on the coordinate axes, which are respectively the first areas. Second area :

[0074] ;

[0075] Let the first area be greater than the second area, that is The range of parameter values ​​that meet the conditions is the range of the second parameter. The intersection of the first and second parameter ranges yields the parameter range of the damping compensation controller. .

[0076] Q4. Select the parameters of the damping compensation controller according to the parameter range. Q4 specifically includes:

[0077] Select the parameters of the damping compensation controller according to the actual requirements based on the parameter range. Solve the expression for the negative sequence equivalent resistance based on the selected damping compensation controller parameters to obtain the corresponding negative sequence equivalent resistance. The feasibility of the parameter design can be verified based on the negative sequence equivalent resistance.

[0078] This invention presents an active damping parameter design method for grid-type flexible DC converter stations. By separating positive and negative sequence impedances, characterizing negative damping using the impedance integral area, and compensating for the negative damping integral area using a damping compensation controller, the method achieves parameter design. This method improves the damping performance of flexible DC transmission systems in the low-frequency range, reduces the risk of low-frequency oscillations when grid-type flexible DC converter stations are connected to the grid, enhances the stability of grid-type flexible DC transmission systems, and enables stable operation of grid-type flexible DC converter stations under a wide range of AC system operating conditions. This method requires no additional parameter debugging steps, has a simple algorithm, is easy to implement, does not affect dynamic and transient operating characteristics, does not change the original control and protection system parameters, and requires no additional hardware equipment. It effectively reduces the risk of low-frequency instability, and the designed parameters have strong robustness.

[0079] In a preferred embodiment of the present invention, an active damping parameter design device for a grid-type flexible DC converter station is also provided, which is used in the method of the present invention. The device includes a first module, a second module, a third module and a fourth module.

[0080] The first module is used to obtain the negative sequence impedance based on the voltage and current at the grid connection point.

[0081] The second module is used to obtain the complex form of the active damping impedance and the original impedance of the converter station based on the negative sequence impedance; based on the active damping impedance and the original impedance of the converter station, a function of the real part of the impedance with respect to frequency is constructed in combination with the damping compensation controller, and the first function and the second function are obtained respectively; the damping compensation controller includes a bandpass filter, a gain resistance value and a gain compensation stage in sequence.

[0082] The third module is used to obtain the negative-sequence equivalent resistance expression of the AC side of the converter station based on the first and second functions; and to obtain the parameter range of the damping compensation controller based on the negative-sequence equivalent resistance expression combined with the integral area method.

[0083] The fourth module is used to select the parameters of the damping compensation controller according to the parameter range.

[0084] The active damping parameter design device for grid-type flexible DC converter stations of the present invention, when used in the method of the present invention, has the same beneficial effects as the method of the present invention.

[0085] Verification section:

[0086] Within the parameter selection range By selecting parameters, the low-frequency negative-sequence impedance characteristic curve or low-frequency negative-sequence equivalent resistance of the grid-type flexible DC converter station is calculated. The impedance characteristics obtained using the method of this invention are as follows: Figure 4 As shown. It can be seen that, under the selected parameters, the negative sequence impedance characteristics of the grid-type flexible DC converter station are calculated, and the negative sequence impedance angle is verified. According to the Nyquist impedance criterion, the impedance angle of the grid-type flexible DC converter station is positively damped within ±90°, and it can prevent oscillation when interacting with the AC system. After using the parameters designed by the method of this invention, the electromagnetic transient impedance model ( Figure 4 The mid-sweep frequency model and the linearized theoretical model ( Figure 4 The amplitude and phase curves of the theoretical model are consistent, and the impedance angle in the low-frequency band meets the Nyquist impedance criterion, that is, it meets the impedance angle requirements in the low-frequency band and can be put into use.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing active damping parameters for a grid-type flexible DC converter station, characterized in that, include: The negative sequence impedance is obtained from the voltage and current at the grid connection point; Based on the negative sequence impedance, the complex form of the active damping impedance and the original impedance of the converter station are obtained; Based on the active damping impedance and the original impedance of the converter station, a function of the real part of the impedance with respect to frequency is constructed using a damping compensation controller, resulting in a first function and a second function. The damping compensation controller sequentially includes a bandpass filter, a gain resistance, and a gain compensation stage. The negative-sequence equivalent resistance expression of the AC side of the converter station is obtained based on the first and second functions. The parameter range of the damping compensation controller is obtained using the negative-sequence equivalent resistance expression combined with the integral area method. Select the parameters of the damping compensation controller according to the parameter range; The expression for the negative sequence equivalent resistance of the AC side of the converter station is obtained based on the first function and the second function; The parameter range of the damping compensation controller, obtained by combining the negative-sequence equivalent resistance expression with the integral area method, includes: Add the first function and the second function to obtain the negative-sequence equivalent resistance expression; set the negative-sequence equivalent resistance expression to be greater than 0, and classify the terms in the negative-sequence equivalent resistance expression according to whether they contain the parameters of the damping compensation controller, to obtain the third function and the fourth function respectively; perform monotonicity analysis based on the combination of the third function and the fourth function, and obtain the parameter range of the damping compensation controller by combining the integral area principle; Based on the monotonicity analysis performed using the combination of the third and fourth functions, and combined with the principle of integral area, the parameter range of the damping compensation controller is obtained as follows: Analyze the monotonicity of the third function to obtain the range in which the third function is greater than 0 within the target frequency band, thus obtaining the first parameter range; analyze the monotonicity of the fourth function to obtain the frequency band in which the fourth function is less than 0, thus obtaining the first frequency band; perform definite integrals on the third and fourth functions within the first frequency band to obtain the first area and the second area enclosing the coordinate axes of the third and fourth functions, respectively; set the first area greater than the second area to obtain the second parameter range; take the intersection of the first parameter range and the second parameter range to obtain the parameter range of the damping compensation controller.

2. The active damping parameter design method for grid-type flexible DC converter stations according to claim 1, characterized in that, The negative sequence impedance is obtained based on the voltage and current at the grid connection point, including: The relationship between voltage and current at the grid connection point of the converter station is obtained by using a linearization method, thus yielding the negative sequence impedance. : ； in, It is a voltage loop PI controller; and These are the proportional and integral coefficients of the voltage loop PI controller, respectively. For the Laplace operator; The power system angular frequency; For damping compensation controllers, in the initial state ; This refers to the number of MMC bridge arm sub-modules. This represents the steady-state value of the MMC DC voltage. This refers to the steady-state DC component of the capacitor voltage of the bridge arm submodule; The equivalent inductance between the AC side and the PCC point of the grid-type flexible DC converter station; The equivalent resistance between the AC side and the PCC point of a grid-type flexible DC converter station; This is a virtual part unit.

3. The active damping parameter design method for grid-type flexible DC converter stations according to claim 2, characterized in that, Based on the active damping impedance and the original impedance of the converter station, combined with the damping compensation controller, a function of the real part of the impedance with respect to frequency is constructed, resulting in the first function and the second function, which include: In the bandpass filter of the damping compensation controller, a pre-selected filter is used for DC filtering; make , , Angular frequency, For the target frequency band range, substitute the expression of the damping compensation controller into the expression of the active damping impedance and the expression of the original impedance of the converter station to obtain the first expression and the second expression respectively; extract the real parts of the first expression and the second expression to obtain the first real part and the second real part; obtain the first function and the second function based on the first real part and the second real part.

4. The active damping parameter design method for grid-type flexible DC converter stations according to claim 3, characterized in that, Also includes: In the bandpass filtering of the damping compensation controller, a second-order bandpass filter is used for DC filtering. Represented as: ； in, , and These represent the gain, resistance, damping ratio, and undamped oscillation angular frequency of a second-order bandpass filter, respectively. This is the undamped oscillation frequency.

5. An active damping parameter design device for a grid-type flexible DC converter station, used in the method described in any one of claims 1 to 4, characterized in that, The device includes a first module, a second module, a third module, and a fourth module; The first module is used to obtain the negative sequence impedance based on the voltage and current at the grid connection point; The second module is used to obtain the complex form of the active damping impedance and the original impedance of the converter station based on the negative sequence impedance; and to construct a function of the real part of the impedance with respect to frequency change based on the active damping impedance and the original impedance of the converter station in combination with the damping compensation controller, thereby obtaining the first function and the second function respectively; the damping compensation controller includes a bandpass filter, a gain resistance value and a gain compensation stage in sequence. The third module is used to obtain the negative sequence equivalent resistance expression of the AC side of the converter station according to the first function and the second function; and to obtain the parameter range of the damping compensation controller according to the negative sequence equivalent resistance expression combined with the integral area method. The fourth module is used to select the parameters of the damping compensation controller according to the parameter range.

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