Electromagnetic relay pull-in voltage adjustment-free rate calculation method based on pull-in counterforce cooperation

Abstract

The invention discloses an electromagnetic relay pull-in voltage adjustment-free rate calculation method based on pull-in counterforce cooperation. The method comprises the following steps: step 1, determining part size and assembly parameter distribution and defining a key position in a pull-in process; 2, electromagnetic suction force single factor analysis and key influence factor screening of key positions in the suction process are carried out; 3, solving the downdraft reaction distribution of a single point position value in the distribution of each key position and calculating the matching reject ratio; step 4, calculating the matching reject ratio of the downdraft reaction force influenced by the distribution of each key position; and 5, calculating the adjustment-free rate of the operation voltage of the relay under the comprehensive influence of the distribution of each key position. According to the method, the pull-in voltage required by the index is taken as the reference, and the matching qualification condition of the pull-in reaction force distribution under the voltage, the influence of the distribution of each key parameter and the key position of the armature in each pull-in process is comprehensively considered, so that the pull-in voltage adjustment-free rate is calculated and obtained, and the pull-in voltage adjustment-free rate of the electromagnetic relay can be accurately and efficiently calculated.

Description

Technical Field

[0001] The invention relates to a method for calculating the adjustment-free rate of an electromagnetic relay, and in particular to a method for calculating the adjustment-free rate of a pull-in voltage of an electromagnetic relay based on pull-in and pull-back force coordination. Background Art

[0002] As a core component of power systems and automatic control systems, electromagnetic relays are widely used in high-tech industries and defense fields due to their high conversion depth and strong anti-interference capabilities, playing the role of converting circuits and safety protection.

[0003] In the production and assembly process of electromagnetic relays, the meaning of the adjustment-free rate is generally defined as the probability that the product can directly meet the requirements of various output characteristic indicators without debugging after assembly. However, electromagnetic relays used in some special occasions need to have strict output characteristics, which greatly increases the difficulty of assembling them without adjustment. Some links need to rely on manual debugging to make the product have the required performance, thereby extending the production cycle and increasing labor costs. In order to reduce costs and increase efficiency, it is usually considered to optimize the design of part dimensions, assembly parameters, etc. in the design stage, and use these parameters to calculate the adjustment-free rate of batch products before prototyping to ensure that the design results meet expectations. The pull-in voltage is one of the key output characteristic indicators of electromagnetic relays. The pull-in voltage adjustment-free rate refers to the probability that the product can directly meet the pull-in voltage requirements without debugging after assembly. The calculation of the pull-in voltage adjustment-free rate can verify and evaluate the design and optimization scheme of the relay, and is one of the important processes in the optimization design of the relay.

[0004] Currently, there is little research in the industry on the calculation method of the pull-in voltage adjustment-free rate. The main ideas are: first, considering all influencing parameters, use random sampling method to obtain parameter samples of batch products; second, use finite element simulation method combined with interpolation to directly solve the electromagnetic attraction characteristics of all samples at the armature release position and under the full range of coil voltage, and directly assume that the reaction force of all samples at the armature release position is the same constant; third, search for the coil voltage corresponding to the electromagnetic attraction and reaction force when they are equal in each sample as the pull-in voltage of each sample, and interpolate and extrapolate the above pull-in voltage results to obtain the probability density function of the pull-in voltage distribution of batch products; finally, directly calculate the probability density area of ​​the pull-in voltage distribution that is higher than the pull-in voltage index through the integral method as the pull-in voltage adjustment-free rate. The above method has the following problems: First, the pull-in voltage is the result of the suction and reaction force matching. If the pull-in voltage distribution is to be solved directly, it is necessary to complete the suction and reaction force matching of each sample one by one. The suction and reaction force matching is a process of adjusting the coil voltage so that the suction force is just higher than the reaction force. If this process is realized by simulation, it is necessary to use the finite element simulation method to obtain the electromagnetic suction force of each sample under different voltages, and then obtain the electromagnetic suction force characteristics of each sample one by one through interpolation and extrapolation, and then search and compare the suction and reaction forces one by one to inversely calculate the pull-in voltage. This makes this type of method have the problems of large calculation amount and low calculation efficiency; second, it is believed that the reaction force of each sample at the armature release position is the same constant, which is inconsistent with the actual production and processing situation. Affected by deviations in part size, assembly parameters, etc., the reaction force of the relay will also exist In terms of distribution, if the same fixed value is considered, the calculation result may not be accurate enough; thirdly, it is considered that the coil voltage when the suction force at the armature release position is just greater than the reaction force is the pull-in voltage. This cognition is not comprehensive enough. If the electromagnetic suction force of the armature at other positions is lower than the reaction force, the relay has a two-step pull-in problem. This product is also not an adjustment-free product, which may lead to inaccurate calculation results of the existing method; fourthly, considering all influencing factors to generate samples and solve the probability density area of ​​the pull-in voltage distribution as the pull-in voltage adjustment-free rate, only the direct reasons affecting the pull-in voltage adjustment-free rate are considered, and the fundamental reasons are not considered in the working principle of the relay. Therefore, the calculation results can only roughly evaluate the pull-in voltage adjustment-free rate under the current design, and cannot provide guiding suggestions for subsequent optimization design. Summary of the invention

[0005] In view of the problems of low calculation efficiency and incomplete consideration in the current method for calculating the adjustment-free rate of the pull-in voltage of a relay, the present invention provides a method for calculating the adjustment-free rate of the pull-in voltage of an electromagnetic relay based on the coordination of suction and reaction forces.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A method for calculating the non-adjustment rate of the electromagnetic relay's pull-in voltage based on pull-in and pull-out force coordination comprises the following steps:

[0008] Step 1: Determine the part size, assembly parameter distribution and define the key positions of the pull-in process:

[0009] Step 1.1, according to the process characteristics of the processing and assembly process of each part of the electromagnetic relay, combined with the working principle of the electromagnetic relay, determine the main influencing parameters affecting its pull-in voltage, and express the pull-in voltage as:

[0010] U(z i ),i∈[1,2,3,…,n];

[0011] Among them, z i represents the i-th parameter, and n represents the total number of main influencing parameters affecting the pull-in voltage;

[0012] Step 1.2: Consider the characteristics of relay production and assembly process, for each z i In terms of in, and Respectively represent the distribution mean and standard deviation of the i-th parameter;

[0013] Step 1.3: To meet the conditions of step 1.2, it is necessary to determine two key positions in the armature stroke during the pull-in process, which are defined as point A and point B. Point A is the armature position in the released state, and point B is the armature position when the static contact spring and the dynamic contact spring are just separated during the pull-in process. The distribution of the two key positions affected by the parameters is expressed as:

[0014] x A (z i )~N A (μ A ,σ A 2 ) and x B (z i )~N B (μ B ,σ B 2 );

[0015] Among them, μ A and μ B Represent the distribution means of point A and point B respectively, σ A and σ B They represent the distribution standard deviations of point A and point B respectively, and the pull-in voltage adjustment-free rate is defined as:

[0016] ρ=(1-P A )·(1-P B );

[0017] Among them, P A and P B Represents the unqualified rate of batch products at point A and point B respectively;

[0018] Step 2: Single factor analysis of electromagnetic suction force at key positions during the suction process and screening of key influencing factors:

[0019] Step 2.1: Combine finite element simulation analysis to solve each main influencing parameter z i Probability density function of electromagnetic attraction distribution at each key position and The impact of F EMF Indicates the magnitude of electromagnetic attraction, F SF Indicates the magnitude of the reaction force. The values ​​of the simulation parameters are taken according to the principle of 3 times the standard deviation:

[0020]

[0021] Step 2.2: Analyze the influence of each parameter on suction and select the most important key influencing parameter z k ,k∈[1,2,3,…m], where z k represents the kth key influencing parameter, and m represents the total number of key influencing parameters;

[0022] Step 3: Solve the suction reaction force distribution and calculate the matching failure rate under the single point position value in each key position distribution:

[0023] Step 3.1: Use exponential sampling to obtain the sampling point value set of each key position and in, and denote the sampling points of point A and point B, respectively; α and β denote the uniformly changing value parameters of the exponential sampling of point A and point B, respectively; h∈{1,2,3,…,c} denotes the hth sampling point, and c denotes the total number of sampling points;

[0024] Step 3.2: Use random sampling to select each and Multiple groups of z k Value combination, for z that follows a normal distribution k , define the sampling distance d(Z j ) and weight value w(Z j ):

[0025]

[0026] Among them, Z j represents the jth group of samples, Indicates the value of the kth key influencing parameter in the jth group of samples, and implements random sampling of key influencing parameter combinations according to their weight values;

[0027] Step 3.3: Perform finite element simulation calculations on the electromagnetic attraction and reaction force for each key influencing parameter combination sample to obtain and The probability density function of the electromagnetic attraction and reaction force distribution under:

[0028]

[0029] in, and They represent the probability density functions of the electromagnetic attraction and reaction force at point A as the position distribution of point A and the distribution of key influencing parameters change, respectively. and They represent the probability density functions of the electromagnetic attraction and reaction force at point B as the position distribution of point B and the distribution of key influencing parameters, μ EMF () and σ EMF () represents the mean and standard deviation of the distribution of electromagnetic attraction force as the armature position changes, μ SF () and σ SF () represents the distribution mean and standard deviation of the reaction force as the armature position changes;

[0030] Step 3.4: Calculate the failure rates of point A and point B as their respective values ​​x A and x B The function of the change g A (x A ) and g B (x B ), according to the existing sampling points, the unqualified rate at each sampling point is obtained by numerical integration:

[0031]

[0032] Step 4: Calculation of the failure rate of suction and reaction force matching under the influence of distribution of each key position:

[0033] Step 4.1: Use the unqualified rate calculation results of the sampling points to establish g A (x A )’s fast calculation model:

[0034]

[0035] Among them, φ() represents the basis function, ε represents the Gaussian parameter, and r represents the distance. represents the hth sampling point, s h represents the interpolation weight of the hth sampling point; to solve the interpolation weight at each sampling point, solve the following linear equations:

[0036]

[0037] in, Represents the δth sampling point, from which the interpolation weight s of each known sampling point is calculated h , and then get the fast calculation model of the unqualified rate of point A:

[0038] g A (x A )=V A (x A );

[0039] Step 4.2: Use the unqualified rate calculation results of the sampling points to establish g B (x B )’s fast calculation model:

[0040]

[0041] Among them, φ() represents the basis function, ε represents the Gaussian parameter, and r represents the distance. represents the hth sampling point, s h represents the interpolation weight of the hth sampling point; to solve the interpolation weight at each sampling point, solve the following linear equations:

[0042]

[0043] in, Represents the δth sampling point, from which the interpolation weight s of each known sampling point is calculated h , and then get the fast calculation model of the failure rate of point B:

[0044] g B (x B )=V B (x B );

[0045] Step 4.3, based on step 4.2 and step 4.2, obtain the unqualified rate under the influence of the distribution of point A and point B:

[0046]

[0047] Step 5: Calculation of relay action voltage free adjustment rate under the comprehensive influence of distribution of key positions:

[0048] According to the calculation formula of the pick-up voltage free adjustment rate, solve the pick-up voltage free adjustment rate of the electromagnetic relay:

[0049] ρ=(1-P A )·(1-P B ).

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] The present invention defines the key positions of the armature suction process that affect the pull-in voltage adjustment-free rate, and considers the single factor analysis of multiple part size parameters and assembly parameters combined with the finite element simulation method to obtain the key influencing factors of the electromagnetic suction force; since each key position itself has a distribution, and the electromagnetic suction force and reaction force under the distribution value of each key position have their own distribution, the calculation of the pull-in voltage adjustment-free rate is regarded as a three-dimensional probability distribution problem, and by gradually solving the suction and reaction force matching situation under the above influence, combining the sampling method and the finite element simulation method, a fast calculation model of the pull-in voltage adjustment-free rate is established, and the overall batch product pull-in voltage adjustment-free rate is solved by integration. In summary, compared with other calculation methods, the present invention starts from the working principle of the relay, takes the pull-in voltage as the benchmark, and comprehensively considers the matching qualified situation of the suction and reaction force distribution under the voltage, the influence of the distribution of each key parameter, and the key position of the armature in each pull-in process, so as to calculate the pull-in voltage adjustment-free rate, which can realize accurate and efficient calculation of the pull-in voltage adjustment-free rate of the electromagnetic relay, and can provide guiding suggestions for subsequent optimization design. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flow chart for calculating the adjustment-free rate of the electromagnetic relay's closing voltage;

[0053] Figure 2 This is an example of the electromagnetic attraction force distribution results for various values ​​of point A. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0055] The present invention provides a method for calculating the voltage adjustment-free rate of an electromagnetic relay based on the coordination of the suction and reaction forces. Figure 1 As shown, the method comprises the following steps:

[0056] Step 1. The electromagnetic relay pull-in voltage adjustment-free rate refers to the probability that the relay product can directly meet the pull-in voltage requirements without debugging after assembly. According to the process characteristics of the electromagnetic relay parts processing, assembly and other processes, combined with the working principle of the electromagnetic relay, the main influencing parameters affecting its pull-in voltage are determined, and the pull-in voltage is expressed as:

[0057] U(z i ),i∈[1,2,3,…,n];

[0058] Among them, z i represents the i-th parameter, and n represents the total number of main influencing parameters that affect the pull-in voltage.

[0059] Considering the characteristics of relay production and assembly process, for each z i In engineering, it is generally believed that the parameters of machine processing are normally distributed, that is:

[0060]

[0061] in, and represent the mean and standard deviation of the distribution of the ith parameter respectively.

[0062] Since the pull-in voltage is the result of the pull-in reaction force matching, the pull-in voltage adjustment-free rate can essentially be understood as the static pull-in force characteristic curve of the relay product is completely higher than the static reaction force characteristic curve under the pull-in voltage required by the index after assembly. Combined with the analysis of the working principle of the relay, it can be seen that in order to meet the above conditions, it is only necessary to determine two key positions in the armature stroke during the pull-in process, which are defined as point A and point B. Among them, point A is the position of the armature in the released state, and the pull-in reaction force matching at this key position determines whether the product can be pulled in under the pull-in voltage; point B is the position of the armature when the static contact spring and the dynamic contact spring are just separated during the pull-in process, and the pull-in reaction force matching at this key position determines whether the product has a two-step pull-in problem. The distributions of the two key positions affected by the parameters are expressed as:

[0063] x A (z i )~N A (μ A ,σ A 2 ) and x B (z i )~N B (μ B ,σ B 2 );

[0064] Among them, μ A and μ B Represent the distribution means of point A and point B respectively, σ A and σ B Represent the distribution standard deviation of point A and point B respectively.

[0065] Therefore, the pull-in voltage adjustment rate can be defined as:

[0066] ρ=(1-P A )·(1-P B );

[0067] Among them, PA and P B They represent the unqualified rate of batch products at points A and B respectively, and the probability that the product's pickup voltage does not need to be adjusted, that is, point A is qualified and point B is qualified.

[0068] Step 2: Combine finite element simulation analysis to solve each main influencing parameter z i Probability density function of electromagnetic attraction distribution at each key position and The impact of F EMF Indicates the magnitude of electromagnetic attraction, F SF Indicates the magnitude of the reaction force. The values ​​of the simulation parameters are taken according to the principle of 3 times the standard deviation:

[0069]

[0070] By analyzing the influence of each parameter on suction, the most important key influencing parameters can be screened out. k ,k∈[1,2,3,…m], thereby reducing the computational complexity of subsequent work, where z k represents the kth key influencing parameter, and m represents the total number of key influencing parameters.

[0071] Step 3: Use exponential sampling to obtain the sampling point value set of each key position and in, and Denote the sampling points of point A and point B, respectively. α and β denote the uniformly changing value parameters of the exponential sampling of point A and point B, respectively. h∈{1,2,3,…,c} denotes the hth sampling point. A total of c sampling points are generated as the value parameters change. At each key position sampling point and Under this condition, the electromagnetic attraction and reaction force are mainly affected by the distribution of key influencing parameters. Therefore, the electromagnetic attraction and reaction force will be normally distributed.

[0072] In order to solve the above distribution and reduce the complexity of finite element simulation, a random sampling method is given to extract each and Multiple groups of z k Value combination. For z that follows a normal distribution k , define the sampling distance d(Z j ) and weight value w(Z j ):

[0073]

[0074] Among them, Z jrepresents the jth group of samples, Indicates the value of the kth key influencing parameter in the jth group of samples. Random sampling of key influencing parameter combinations is achieved based on their weight values.

[0075] Finite element simulation calculations of electromagnetic attraction and reaction force were performed on these key parameter combination samples one by one to obtain the and The probability density function of the electromagnetic attraction and reaction force distribution under:

[0076]

[0077] in, and They represent the probability density functions of the electromagnetic attraction and reaction force at point A as the position distribution of point A and the distribution of key influencing parameters change, respectively. and They represent the probability density functions of the electromagnetic attraction and reaction force at point B as the position distribution of point B and the distribution of key influencing parameters, μ EMF () and σ EMF () represents the mean and standard deviation of the distribution of electromagnetic attraction force as the armature position changes, μ SF () and σ SF () represents the distribution mean and standard deviation of the reaction force as the armature position changes. Taking the electromagnetic suction force distribution at point A as an example, the results that can be obtained are as follows: Figure 2 shown.

[0078] Since the condition for the relay to avoid adjustment of the pull-in voltage is that the electromagnetic attraction at point A and point B is greater than the reaction force under the specified pull-in voltage, the failure rate of point A and point B is calculated as a function of their respective values ​​x. A and x B The function of the change g A (x A ) and g B (x B ). According to the existing sampling points, the failure rate at each sampling point can be obtained by numerical integration:

[0079]

[0080] Step 4: Use the above sampling point unqualified rate calculation results to establish g A (x A ) and g B (x B ), taking point A as an example:

[0081]

[0082] Among them, φ() represents the basis function, ε represents the Gaussian parameter, and r represents the distance. represents the hth sampling point, s h represents the interpolation weight of the hth sampling point, and c represents the total number of sampling points. To solve the interpolation weight at each sampling point, solve the following linear equations:

[0083]

[0084] in, Represents the δth sampling point, from which the interpolation weight s of each known sampling point can be calculated h , and then get the fast calculation model of the unqualified rate of point A:

[0085] g A (x A )=V A (x A ).

[0086] The method for establishing the fast calculation model of the non-conforming rate at point B is the same as that at point A.

[0087] Thus, the unqualified rate under the influence of the distribution of points A and B is obtained:

[0088]

[0089] Step 5. According to the calculation formula of the pick-up voltage free adjustment rate, solve the pick-up voltage free adjustment rate of the electromagnetic relay:

[0090] ρ=(1-P A )·(1-P B );

[0091] At this point, the calculation of the electromagnetic relay's voltage adjustment-free rate is completed.

[0092] Combined with the example, calculate the failure rate of point A of a certain type of electromagnetic relay as P A =26.3%, the failure rate of point B is P B =22.3%, then the pick-up voltage adjustment-free rate ρ = 57.26%. A batch of samples of this design were actually processed, and the measured and statistical pick-up voltage adjustment-free rate of the batch products was 58%. The calculated relative error is:

[0093] E R =(58%-57.26%) / 58%×100%≈1.28%.

Claims

1. A method for calculating the non-adjustment rate of the electromagnetic relay's pull-in voltage based on the pull-in and pull-back force coordination, characterized in that The method comprises the following steps: Step 1: Determine the part size, assembly parameter distribution and define the key positions of the pull-in process: Step 1.1, according to the process characteristics of the processing and assembly process of each part of the electromagnetic relay, combined with the working principle of the electromagnetic relay, determine the main influencing parameters affecting its pull-in voltage, and express the pull-in voltage as: U(z i ),i∈[1,2,3,…,n]; Among them, z i represents the i-th parameter, and n represents the total number of main influencing parameters affecting the pull-in voltage; Step 1.2: Consider the characteristics of relay production and assembly process, for each z i In terms of in, and Respectively represent the distribution mean and standard deviation of the i-th parameter; Step 1.3: To meet the conditions of step 1.2, it is necessary to determine two key positions in the armature stroke during the pull-in process, which are defined as point A and point B. Point A is the armature position in the released state, and point B is the armature position when the static contact spring and the dynamic contact spring are just separated during the pull-in process. The distribution of the two key positions affected by the parameters is expressed as: x A (z i )~N A (μ A ,σ A 2 ) and x B (z i )~N B (μ B ,σ B 2 ); Among them, μ A and μ B Represent the distribution means of point A and point B respectively, σ A and σ B They represent the distribution standard deviations of point A and point B respectively, and the pull-in voltage adjustment-free rate is defined as: ρ=(1-P A )·(1-P B ); Among them, P A and P B Represents the unqualified rate of batch products at point A and point B respectively; Step 2: Single factor analysis of electromagnetic suction force at key positions during the suction process and screening of key influencing factors: Step 2.1: Combine finite element simulation analysis to solve each main influencing parameter z i Probability density function of electromagnetic attraction distribution at each key position and The impact of F EMF Indicates the magnitude of electromagnetic attraction, F SF Indicates the size of the reaction force; Step 2.2: Analyze the influence of each parameter on suction and select the most important key influencing parameter z k ,k∈[1,2,3,…m], where z k represents the kth key influencing parameter, and m represents the total number of key influencing parameters; Step 3: Solve the suction reaction force distribution and calculate the matching failure rate under the single point position value in each key position distribution: Step 3.1: Use exponential sampling to obtain the sampling point value set of each key position and in, and denote the sampling points of point A and point B, respectively; α and β denote the uniformly changing value parameters of the exponential sampling of point A and point B, respectively; h∈{1,2,3,…,c} denotes the hth sampling point, and c denotes the total number of sampling points; Step 3.2: Use random sampling to select each and Multiple groups of z k Value combination, for z that follows a normal distribution k , define the sampling distance d(Z j ) and weight value w(Z j ): Among them, Z j represents the jth group of samples, Indicates the value of the kth key influencing parameter in the jth group of samples, and implements random sampling of key influencing parameter combinations according to their weight values; Step 3.3: Perform finite element simulation calculations on the electromagnetic attraction and reaction force for each key influencing parameter combination sample to obtain and The probability density function of the electromagnetic attraction and reaction force distribution under: in, and They represent the probability density functions of the electromagnetic attraction and reaction force at point A as the position distribution of point A and the distribution of key influencing parameters change, respectively. and They represent the probability density functions of the electromagnetic attraction and reaction force at point B as the position distribution of point B and the distribution of key influencing parameters, μ EMF () and σ EMF () represents the mean and standard deviation of the distribution of electromagnetic attraction force as the armature position changes, μ SF () and σ SF () represents the distribution mean and standard deviation of the reaction force as the armature position changes; Step 3.4: Calculate the failure rates of point A and point B as their respective values ​​x A and x B The function of the change g A (x A ) and g B (x B ), according to the existing sampling points, the failure rate at each sampling point is obtained by numerical integration: Step 4: Calculation of the failure rate of suction and reaction force matching under the influence of distribution of each key position: Step 4.1: Use the unqualified rate calculation results of the sampling points to establish g A (x A )’s fast calculation model: Among them, φ() represents the basis function, ε represents the Gaussian parameter, and r represents the distance. represents the hth sampling point, s h represents the interpolation weight of the hth sampling point; to solve the interpolation weight at each sampling point, solve the following linear equations: in, Represents the δth sampling point, from which the interpolation weight s of each known sampling point is calculated h , and then get the fast calculation model of the unqualified rate of point A: g A (x A )=V A (x A ); Step 4.2: Use the unqualified rate calculation results of the sampling points to establish g B (x B )’s fast calculation model: Among them, φ() represents the basis function, ε represents the Gaussian parameter, and r represents the distance. represents the hth sampling point, s h represents the interpolation weight of the hth sampling point; to solve the interpolation weight at each sampling point, solve the following linear equations: in, Represents the δth sampling point, from which the interpolation weight s of each known sampling point is calculated h , and then get the fast calculation model of the failure rate of point B: g B (x B )=V B (x B ); Step 4.3, based on step 4.2 and step 4.2, obtain the unqualified rate under the influence of the distribution of point A and point B: Step 5: Calculation of relay action voltage free adjustment rate under the comprehensive influence of distribution of key positions: According to the calculation formula of the pick-up voltage free adjustment rate, solve the pick-up voltage free adjustment rate of the electromagnetic relay.

2. The method for calculating the electromagnetic relay pull-in voltage adjustment-free rate based on pull-in and pull-out force coordination according to claim 1 is characterized in that In step 2.1, the values ​​of the simulation parameters are taken according to the principle of three times standard deviation:

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