Method for evaluating vibration impedance performance of rotor hub of range extender

Abstract

The invention discloses an evaluation method for vibration impedance performance of a range extender rotor hub, and the method comprises the steps: setting a plurality of response points on the surface of the rotor hub, and enabling the response points to be distributed at two axial sides and to be circumferentially symmetrical; broadband sine excitation is applied to the radial direction of each response point, and excitation force and multidirectional vibration response of each point are recorded; calculating a global vibration impedance response function based on the exciting force and the vibration response data, and drawing a vibration impedance curve; based on the vibration impedance curve, a radial secondary mode, a radial tertiary mode, a shafting primary core mode and a shafting secondary core mode of the vibration impedance curve are identified respectively, and related numerical values are recorded; and then calculating a radial vibration impedance coefficient RK according to the radial modal parameters, calculating a shafting vibration impedance coefficient SK according to the shafting modal parameters, calculating a total vibration impedance coefficient by combining the RK and the SK, and performing grading evaluation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric drive technology for new energy vehicles, and particularly relates to a method for evaluating vibration impedance performance of a rotor hub of a range extender. BACKGROUND

[0002] With the rapid development of the new energy vehicle market, consumers' demand for driving range is increasingly urgent. As an effective solution, range-extended electric vehicles can reduce the dependence of batteries on driving range while ensuring the charging efficiency of the vehicle, thereby effectively alleviating the "range anxiety". Unlike traditional pure electric vehicles, range-extended electric vehicles provide additional power support for the battery through the on-board range extender, thereby achieving longer driving range without relying on external charging facilities. Therefore, the performance of the range extender is of great significance to improve the fuel economy and market competitiveness of the whole vehicle.

[0003] One of the core components of the on-board range extender is the rotor hub. Inside the rotor hub, the interaction between the permanent magnet and the stator armature current generates a magnetic field and converts mechanical energy into electrical energy to charge the battery. The design of the rotor hub directly affects the operating efficiency, stability and durability of the range extender. Therefore, optimizing the design and improving the performance of the rotor hub is the key to improving the overall performance of the range extender.

[0004] However, the structure of the rotor hub is complex, and the manufacturing process involves multiple-step process flow. The performance evaluation of the rotor hub has many challenges. Currently, the automotive industry usually relies on whole vehicle durability testing to evaluate the performance of the rotor hub, including its durability, vibration resistance and noise resistance performance. However, this evaluation method has obvious shortcomings: on the one hand, the whole vehicle durability test has a long cycle, and effective evaluation conclusions cannot be obtained in the early stages of product development; on the other hand, the resources consumed in the test process are huge, especially in the investment of test vehicles and related equipment, which brings great cost pressure to enterprises. In addition, due to the lack of precise early-stage verification means for the structural design and process stability of the rotor hub, the adjustment and optimization process of the product after production also faces greater challenges. Therefore, how to quickly and accurately evaluate the performance of the rotor hub, especially its vibration impedance characteristics, without relying on whole vehicle resources, has become a difficult problem to be solved in the field of automotive engineering technology. SUMMARY

[0005] In view of the above shortcomings of the prior art, the technical problem to be solved by the present application is to provide a method for accurately analyzing the vibration impedance characteristics of the rotor hub without relying on whole vehicle resources.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] A method for evaluating the rotor hub vibration impedance performance of a range extender includes the following steps:

[0008] (1) Establish a cylindrical coordinate system with the geometric center of the rotor hub end face as the origin. On the edges of the two axial end faces of the rotor hub, set multiple response points at equal intervals along the circumference. The response points on the two end faces are opposite each other along the rotor hub axis. In the cylindrical coordinate system, apply sinusoidal excitation to the radial direction of each response point in sequence, and record the radial excitation force values ​​and the vibration acceleration values ​​in the radial x, axial y, and tangential z directions of all response points. Calculate the vibration response function value YY of each response point in each direction at each excitation frequency. jd (f), d∈{x,y,z}, j is the number of single-surface response points; based on the vibration response function value YY jd (f) Calculate the global vibration impedance response function and plot the rotor hub vibration impedance curve;

[0009] (2) Based on the rotor hub vibration impedance curve in step (1), identify its radial second-order mode, radial third-order mode, shaft system first-order core mode, and shaft system second-order core mode, and record the radial second-order mode frequency f. r2 and the corresponding impedance value YY d (f r2 ), radial third modal frequency f r3 and the corresponding impedance value YY d (f r3 ), the first core mode frequency f of the shaft system s1 and the corresponding impedance value YY d (f s1 ), the second core mode frequency f of the shaft system s2 and the corresponding impedance value YY d (f s2 );

[0010] (3) Based on the radial modal parameters in step (2), calculate the rotor hub radial vibration impedance coefficient:

[0011] RK = B1 * (f r3 +f r2 ) / 2+B2*abs((f r3 -f r2 ) / f r3 )+B3*(1 / YY d (f r2 )+1 / YY d (f r3 ))+B4*abs(YY d (f r2 )-YY d (f r3 ) / YY d (f r2))

[0012] In the formula, B1, B2, B3, and B4 are coefficients, with B1 = 0.00025, B2 = 1, B3 = 0.125, and B4 = 1, respectively.

[0013] Calculate the vibration impedance coefficient of the rotor hub shaft system based on the core modal parameters of the shaft system:

[0014] SK = C1*(f s1 +f s2 ) / 2+C2*abs((f s1 -f s2 ) / f s1 )+C3*(1 / YY d (f s1 )+1 / YY d (f s2 ))+C4*abs(YY d (f s1 )-YY d (f s2 ) / YY d (f s1 ))

[0015] In the formula, C1, C2, C3, and C4 are coefficients, with C1 = 0.00025, C2 = 1, C3 = 0.125, and C4 = 1, respectively.

[0016] (4) Calculate the rotor hub vibration impedance coefficient:

[0017] WK = RK + k * SK

[0018] In the formula, k is the weighting coefficient; based on the WK value, the rotor hub vibration impedance performance is evaluated in accordance with the preset rating standard.

[0019] As an optimization, in step (1), a sinusoidal excitation force with a frequency range from fmin to fmax is applied to the response point, where fmin ≤ 150 Hz, fmax ≥ 4000 Hz, and the frequency interval 1 Hz ≤ Δf ≤ 5 Hz.

[0020] As an optimization, in step (1), the global vibration impedance response function is calculated using the following formula:

[0021]

[0022] In the formula, n is the total number of response points, YY 正jd (f) and YY 反jd (f) represents the vibration response function of the rotor hub at two corresponding response points on the two end faces.

[0023] As an optimization, in step (4), the weight coefficient k satisfies 0.6≤k≤0.7.

[0024] As an optimization, the weighting coefficient k = 0.65.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The method of the present invention can predict the performance of the rotor hub in the design stage, avoiding the long cycle of vehicle durability testing and greatly shortening the product development and iteration cycle.

[0027] (2) This invention replaces a large number of real vehicle tests with virtual analysis, reducing the investment in test vehicles and testing equipment, and significantly reducing the cost of the product verification stage;

[0028] (3) By accurately analyzing the vibration impedance characteristics of the rotor hub, key factors affecting the durability, vibration resistance and noise resistance of the rotor hub can be identified and optimized in advance. Attached Figure Description

[0029] Figure 1 This is a flowchart of the present invention;

[0030] Figure 2 This is the rotor hub vibration impedance curve in this invention;

[0031] Figure 3 This refers to the radial second-order modal diagram identified in this invention;

[0032] Figure 4 This refers to the radial tertiary modal diagram identified in this invention;

[0033] Figure 5 This is the first-order core mode diagram of the shaft system identified in this invention;

[0034] Figure 6 This is the second core mode diagram of the shaft system identified in this invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, the method for evaluating the rotor hub vibration impedance performance of the range extender in this specific embodiment includes the following steps:

[0037] (1) Establish a cylindrical coordinate system with the geometric center of the rotor hub end face as the origin. On the edges of the two axial end faces of the rotor hub, set multiple response points at equal intervals along the circumference. The response points on the two end faces are opposite each other along the rotor hub axis. In the cylindrical coordinate system, apply sinusoidal excitation to the radial direction of each response point in sequence, and record the radial excitation force values ​​and the vibration acceleration values ​​in the radial x, axial y, and tangential z directions of all response points. Calculate the vibration response function value YY of each response point in each direction at each excitation frequency. jd (f), d∈{x,y,z}, j is the number of single-surface response points; based on the vibration response function value YY jd (f) Calculate the global vibration impedance response function and plot the rotor hub vibration impedance curve;

[0038] (2) Based on the rotor hub vibration impedance curve in step (1), identify its radial second-order mode, radial third-order mode, shaft system first-order core mode, and shaft system second-order core mode, and record the radial second-order mode frequency f. r2 and the corresponding impedance value YY d (f r2 ), radial third modal frequency f r3 and the corresponding impedance value YY d (f r3 ), the first core mode frequency f of the shaft system s1 and the corresponding impedance value YY d (f s1 ), the second core mode frequency f of the shaft system s2 and the corresponding impedance value YY d (f s2 );

[0039] (3) Based on the radial modal parameters in step (2), calculate the rotor hub radial vibration impedance coefficient:

[0040] RK = B1 * (f r3 +f r2 ) / 2+B2*abs((f r3 -f r2 ) / f r3 )+B3*(1 / YY d (f r2 )+1 / YY d (f r3 ))+B4*abs(YY d (f r2 )-YY d (f r3 ) / YY d (f r2 ))

[0041] In the formula, B1, B2, B3, and B4 are coefficients, with B1 = 0.00025, B2 = 1, B3 = 0.125, and B4 = 1, respectively.

[0042] Calculate the vibration impedance coefficient of the rotor hub shaft system based on the core modal parameters of the shaft system:

[0043] SK = C1*(f s1 +f s2 ) / 2+C2*abs((f s1 -f s2 ) / f s1 )+C3*(1 / YY d (f s1 )+1 / YY d (f s2 ))+C4*abs(YY d (f s1 )-YY d (f s2 ) / YY d (f s1 ))

[0044] In the formula, C1, C2, C3, and C4 are coefficients, with C1 = 0.00025, C2 = 1, C3 = 0.125, and C4 = 1, respectively.

[0045] (4) Calculate the rotor hub vibration impedance coefficient:

[0046] WK = RK + k * SK

[0047] In the formula, k is the weighting coefficient; based on the WK value, the rotor hub vibration impedance performance is evaluated in accordance with the preset rating standard.

[0048] In step (1), a sinusoidal excitation force with a frequency range from fmin to fmax is applied to the response point, where fmin ≤ 150 Hz, fmax ≥ 4000 Hz, and the frequency interval 1 Hz ≤ Δf ≤ 5 Hz.

[0049] In step (1), the global vibration impedance response function is calculated using the following formula:

[0050]

[0051] In the formula, n is the total number of response points, YY 正jd (f) and YY 反jd (f) represents the vibration response function of the rotor hub at two corresponding response points on the two end faces.

[0052] In step (4), the weighting coefficient k satisfies 0.6≤k≤0.7.

[0053] In practical implementation, a cylindrical coordinate system is first established based on the rotor hub: the radial direction of the rotor hub assembly is the radial direction, its axial direction is the axial direction, and the tangential direction of the outer diameter arc is the tangential direction. Sixteen response points are taken at 22.5° intervals along the outer edges of the front and back sides of the rotor hub. The points on the axial direction of the front and back sides correspond one-to-one; denoted as positive 1, positive 2..., positive 16; negative 1, negative 2..., negative 16; for a total of 32 response points. A sinusoidal excitation in the radial direction of these 32 points is sequentially applied using an excitation source within the range of 100Hz to 5000Hz (1Hz interval). During the excitation process, the radial excitation force values ​​and the radial / axial / tangential vibration acceleration values ​​are recorded for all 32 points. The vibration impedance function is calculated sequentially under each excitation frequency condition according to the following formula:

[0054] YY 正jd (f)=A 正jd (f) / FF 正j (f)

[0055] YY 反jd (f)=A 反jd (f) / FF 反j (f)

[0056] In the formula: YY 正jd (f) represents the vibration response function of the positive jd-th point (j = 1, 2, 3, ..., 16) in the d-direction (d = x, y, z) under the condition of excitation frequency = fHz. A 正jd (f) represents the vibration acceleration value of the j-th point in the d direction under the condition of excitation frequency fHz. FF 正j(f) represents the radial excitation force value at the j-th point under the condition of excitation frequency fHz. The second formula has the same meaning as the first, only representing the opposite.

[0057] YY corresponding to 100Hz~5000Hz 正jd The value of (f) and YY 乙jd The values ​​of (f) are summarized, and the vibration impedance response function at the excitation frequency is calculated according to the following formula.

[0058]

[0059] In the formula: YY d (f) represents the vibration impedance response function under the condition of excitation frequency fHz.

[0060] The vibration impedance response functions of 4900 samples obtained from 100Hz to 5000Hz were plotted with frequency on the x-axis and response value on the y-axis. The resulting curve shows the vibration impedance curve of the rotor hub of the vehicle-mounted range extender. Figure 2 As shown.

[0061] Obtaining radial core modal parameters of the rotor hub of the vehicle-mounted range extender: Establishing a 10th-order fitting function: YY d (f)=bb 10 *(f-f1)*(f-f2)*(f-f3)*...-(ff 10 )

[0062] In the formula: f1, f2, f3...f 10 These are the ten highest peaks on the rotor hub vibration impedance curve. 10 These are the fitting coefficients. The least squares method is used to fit bb. 10 The value of .

[0063] Establish an 11th-order fitting function: YY d (f)=bb 11 *(f-f1)*(f-f2)*(f-f3)*...*(ff 11 )

[0064] In the formula: bb 11 These are the fitting coefficients. The least squares method is used to fit bb. 11 The value of f. 11 These are the 11th highest peaks on the rotor hub vibration impedance curve.

[0065] If abs((bb) is satisfied 10 -bb 11 ) / bb 10 If the value is less than 0.5%, then stop building the new function. If this condition is not met, then build a 12th-order fitting function to obtain bb. 12Then use abs((bb 11 -bb 12 ) / bb 11 If the result is less than 0.5%, a 13th-order fitting function is established, and so on, until abs((bb) is satisfied. n -bb n+1 ) / bb n Stop iterating when the percentage of cases is less than 0.5%.

[0066] After stopping the iteration, the radial second-order and radial third-order mode frequencies were confirmed.

[0067] Select the vibration impedance YY at frequency f1 d (f1). If the vibration impedance satisfies:

[0068] 1)Max((YY 正jy (f1)-YY 反jy (f1)) / YY 正jy (f1))<10% (j=1,2,3,...,16)

[0069] 2)Max((YY 正jz (f1)-YY 反jz (f1)) / YY 正jz (f1))<10% (j=1,2,3,...,16)

[0070] 3)Min(ZZ 正jx (f1))<0.1*Max(ZZ 正jx (f1))andMin(ZZ) 反jx (f1))<0.1*Max(ZZ 反jx (f1))

[0071] 4)ZZ 正jx (f) The amplitude difference between any two of the four largest points in the amplitude range is within 10%, and the spatial angular interval is 90° or 180°.

[0072] 5)ZZ 反jx (f) The amplitude difference between any two of the four largest points in the amplitude range is within 10%, and the spatial angular interval is 90° or 180°.

[0073] If the impedance at frequency f1 satisfies all the above conditions, then that frequency is the radial second mode; otherwise, continue analyzing at frequency f2. Continue until a frequency that satisfies the conditions is found; this is the radial second mode. Record this frequency: f r2 =2387; the impedance value here is YY d (f r2=0.27, the identified radial second-order modal diagram is as follows Figure 3 As shown.

[0074] Select the vibration impedance YY at frequency f1 d (f1). If the vibration impedance satisfies:

[0075] 1)Max((YY 正jy (f1)-YY 反jy (f1)) / YY 正jy (f1))<8% (j=1,2,3,...,16)

[0076] 2)Max((YY 正jz (f1)-YY 反jz (f1)) / YY 正jz (f1))<8% (j=1,2,3,...,16)

[0077] 3)Min(ZZ 正jx (f1))<0.15*Max(ZZ 正jx (f1))andMin(ZZ) 反jx (f1))<0.15*Max(ZZ 反jx (f1))

[0078] 4)ZZ 正jx (f) The amplitude difference between any two of the three largest amplitude points is within 8%, and the spatial angular interval is 120°±15°.

[0079] 5)ZZ 反jx (f) The amplitude difference between any two of the three largest amplitude points is within 8%, and the spatial angular interval is 120°±15°.

[0080] If the impedance at frequency f1 satisfies all the above conditions, then that frequency is the radial third mode; otherwise, continue analyzing at frequency f2. Continue until a frequency that satisfies the conditions is found; this is the radial third mode. Record this frequency: f r3 =4819; the impedance value here is YY d (f r3 =0.50, the identified radial cubic modal diagram is as follows Figure 4 As shown.

[0081] Acquisition of core modal parameters of the rotor hub shaft system of the vehicle range extender assembly: vibration impedance curve of the rotor hub of the vehicle range extender and peak frequency identification iteration strategy in step 2, identification of the first and second core modal parameters of the rotor hub shaft system of the vehicle range extender assembly.

[0082] Select the vibration impedance YY at frequency f1 d(f1). If the vibration impedance satisfies:

[0083] 1)Max((YY 正jy (f1)-YY 反jy (f1)) / YY 正jy (f1))<6% (j=1,2,3,...,16)

[0084] 2)Min(ZZ 正jz (f1))<0.1*Max(ZZ 正jz (f1))andMin(ZZ) 反jz (f1))<0.1*Max(ZZ 反jz (f1))

[0085] 3)Min(ZZ 正jx (f1))<0.1*Max(ZZ 正jx (f1))andMin(ZZ) 反jx (f1))<0.1*Max(ZZ 反jx (f1))

[0086] 4)ZZ 正jx (f) The amplitude difference between the two largest amplitude points is within 10%, and the spatial angular interval is 180°.

[0087] 5)ZZ 反jx (f) The amplitude difference between the two largest amplitude points is within 10%, and the spatial angular interval is 180°.

[0088] 6)ZZ 正jz (f) The amplitude difference between any two of the four largest points in the amplitude range is within 10%, and the spatial angular interval is 90° or 180°.

[0089] 7)ZZ 反jz (f) The amplitude difference between any two of the four largest points in the amplitude range is within 10%, and the spatial angular interval is 90° or 180°.

[0090] If the impedance at frequency f1 satisfies all the above conditions, then that frequency is the first core mode of the rotor hub-shaft system; otherwise, continue analyzing at frequency f2. Continue until a frequency that satisfies the conditions is found; this is the first core mode of the rotor hub-shaft system. Record this frequency: f s1 =1714; the impedance value here is YY d (f s1 =0.54, the identified first-order core mode diagram of the rotor hub-shaft system is as follows Figure 5 As shown.

[0091] Select the vibration impedance YY at frequency f1d (f1). If the vibration impedance satisfies:

[0092] 1)Max((YY 正jy (f1)-YY 反jy (f1)) / YY 正jy (f1))<8% (j=1,2,3,...,16)

[0093] 2)Min(ZZ 正jz (f1))<0.12*Max(ZZ 正jz (f1))andMin(ZZ) 反jz (f1))<0.12*Max(ZZ 反jz (f1))

[0094] 3)Min(ZZ 正jx (f1))<0.12*Max(ZZ 正jx (f1))andMin(ZZ) 反jx (f1))<0.12*Max(ZZ 反jx (f1))

[0095] 4)ZZ 正jx (f) The amplitude difference between any two of the three largest amplitude points is within 10%, and the spatial angular interval is 120°±15°.

[0096] 5)ZZ 反jx (f) The amplitude difference between any two of the three largest amplitude points is within 10%, and the spatial angular interval is 120°±15°.

[0097] 6)ZZ 正jx (f) The amplitude difference between any two of the three largest amplitude points is within 8%, and the spatial angular interval is 120°±15°.

[0098] 7)ZZ 反jx (f) The amplitude difference between any two of the three largest amplitude points is within 8%, and the spatial angular interval is 120°±15°.

[0099] If the impedance at frequency f1 satisfies all the above conditions, then that frequency represents the second core mode of the rotor hub-shaft system. If not, continue analyzing at frequency f2. Continue until a frequency that satisfies the conditions is found; this is the second core mode of the rotor hub-shaft system. Record this frequency: f s2 =4221; the impedance value here is YY d (f s2 =0.62, the identified rotor hub-shaft system second-order core mode diagram is as follows Figure 6 As shown.

[0100] According to the formula:

[0101] RK = B1 * (f r3 +f r2 ) / 2+B2*abs((f r3 -f r2 ) / f r3 )+B3*(1 / YY d (f r2 )+1 / YY d (f r3 ))+B4*abs(YY d (f r2 )-YY d (f r3 ) / YY d (f r2 ))

[0102] The rotor hub radial vibration impedance coefficient RK is calculated to be 2.98.

[0103] According to the formula:

[0104] SK = C1*(f s1 +f s2 ) / 2+C2*abs((f s1 -f s2 ) / f s1 )+C3*(1 / YY d (f s1 )+1 / YY d (f s2 ))+C4*abs(YY d (f s1 )-YY d (f s2 ) / YY d (f s1 ))

[0105] The vibration impedance coefficient of the rotor hub shaft system is calculated to be SK = 1.84.

[0106] Finally, according to the formula:

[0107] WK = RK + 0.65 * SK

[0108] The calculated vibration impedance coefficient WK of the on-board range extender rotor hub is 4.18. Based on the preset rating criteria, as shown in Table 1, the vibration impedance performance of the on-board range extender rotor hub is scored and rated. In this example, the score is 4 points, indicating a high-risk level, which means the quality of the rotor hub does not meet the relevant requirements.

[0109]

[0110] Table 1

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A method for evaluating the vibration impedance performance of a range extender rotor hub, characterized in that: Includes the following steps: (1) Establish a cylindrical coordinate system with the geometric center of the rotor hub end face as the origin. On the edges of the two axial end faces of the rotor hub, set multiple response points at equal intervals along the circumference. The response points on the two end faces are opposite each other along the rotor hub axis. In the cylindrical coordinate system, apply sinusoidal excitation to the radial direction of each response point in sequence, and record the radial excitation force values ​​and the vibration acceleration values ​​in the radial x, axial y, and tangential z directions of all response points. Calculate the vibration response function value YY of each response point in each direction at each excitation frequency. jd (f), d∈{x,y,z}, j is the number of single-surface response points; based on the vibration response function value YY jd (f) Calculate the global vibration impedance response function and plot the rotor hub vibration impedance curve; (2) Based on the rotor hub vibration impedance curve in step (1), identify its radial second-order mode, radial third-order mode, shaft system first-order core mode, and shaft system second-order core mode, and record the radial second-order mode frequency f. r2 and the corresponding impedance value YY d (f r2 ), radial third modal frequency f r3 and the corresponding impedance value YY d (f r3 The first core mode frequency f of the shaft system s1 and the corresponding impedance value YY d (f s1 ), the second core mode frequency f of the shaft system s2 and the corresponding impedance value YY d (f s2 ); (3) Based on the radial modal parameters in step (2), calculate the rotor hub radial vibration impedance coefficient: RK=B1*(f r3 +f r2 ) / 2+B2*abs((f r3 -f r2 ) / f r3 )+B3*(1 / YY d (f r2 )+1 / YY d (f r3 ))+B4*abs(YY d (f r2 )-YY d (f r3 ) / YY d (f r2 )) In the formula, B1, B2, B3, and B4 are coefficients, with B1 = 0.00025, B2 = 1, B3 = 0.125, and B4 = 1, respectively. Calculate the vibration impedance coefficient of the rotor hub shaft system based on the core modal parameters of the shaft system: SK=C1*(f s1 +f s2 ) / 2+C2*abs((f s1 -f s2 ) / f s1 )+C3*(1 / YY d (f s1 )+1 / YY d (f s2 ))+C4*abs(YY d (f s1 )-YY d (f s2 ) / YY d (f s1 )) In the formula, C1, C2, C3, and C4 are coefficients, with C1 = 0.00025, C2 = 1, C3 = 0.125, and C4 = 1, respectively. (4) Calculate the rotor hub vibration impedance coefficient: WK = RK + k * SK In the formula, k is the weighting coefficient; based on the WK value, the rotor hub vibration impedance performance is evaluated in accordance with the preset rating standard.

2. The method for evaluating the rotor hub vibration impedance performance of a range extender according to claim 1, characterized in that: In step (1), a sinusoidal excitation force with a frequency range from fmin to fmax is applied to the response point, where fmin ≤ 150 Hz, fmax ≥ 4000 Hz, and the frequency interval 1 Hz ≤ Δf ≤ 5 Hz.

3. The method for evaluating the rotor hub vibration impedance performance of a range extender according to claim 1, characterized in that: In step (1), the global vibration impedance response function is calculated using the following formula: In the formula, n is the total number of response points, YY 正jd (f) and YY 反jd (f) represents the vibration response function of the rotor hub at two corresponding response points on the two end faces.

4. The method for evaluating the rotor hub vibration impedance performance of a range extender according to claim 1, characterized in that: In step (4), the weighting coefficient k satisfies 0.6≤k≤0.

7.

5. The method for evaluating the rotor hub vibration impedance performance of a range extender according to claim 4, characterized in that: The weighting coefficient k = 0.65.

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