RL output filter design method for motor driving, filter and system

Abstract

The invention belongs to the technical field of electric driving, and provides an RL output filter design method for motor driving, a filter and a system, and the method comprises the steps: determining cable impedance according to related parameters of a cable; determining motor impedance according to the determined cable impedance and the motor related parameters; determining the impedance of the RL filter according to the cable impedance, the motor impedance and an impedance matching principle; determining a filter resistance parameter range according to the RL filter impedance; determining a filter inductance parameter range according to the filter resistance value and the filter cut-off frequency; according to the filter resistance parameter range and the filter inductance parameter range, determining a filter resistance value and a filter inductance value by taking filter power consumption as a limiting condition; on the basis of the impedance matching principle and the high-frequency harmonic suppression requirement, resistance and inductance parameter design is completed, parameter configuration is optimized through loss calculation, and it is ensured that the filter has the advantages of being low in loss and small in size while suppressing overvoltage at the motor end.

Description

Technical Field

[0001] This invention belongs to the field of electric drive technology, and particularly relates to a design method, filter and system for an RL output filter used in motor drive. Background Technology

[0002] In the field of electric drives, inverters and motors are often connected by long cables. The distributed inductance and capacitance of the cable form a distributed parameter network, which, under the action of high-frequency pulse voltage, induces voltage wave reflection, resulting in overvoltage spikes and high-frequency oscillations at the motor end that far exceed the bus voltage. To solve this problem, a filter is usually installed on the output side of the inverter. Among them, RL (Resistor-inductor circuit) filters are widely used due to their simple structure and good high-frequency attenuation and impedance matching capabilities.

[0003] Traditional RL filter design methods fail to fully consider the combined effects of long cable distributed parameters and motor high-frequency impedance, resulting in poor impedance matching and limited suppression effects. Resistance and inductance parameters are often designed in isolation, lacking system optimization, and there is a lack of clear reasoning for determining the final and optimized parameters. Furthermore, the motor impedance dynamically changes with frequency and load, making accurate measurement difficult, further increasing the matching difficulty of fixed-parameter filters. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a design method, filter, and system for an RL output filter used in motor drives. This invention clarifies the system's fundamental parameters through cable parameter measurement and motor impedance estimation. Based on impedance matching principles and high-frequency harmonic suppression requirements, it completes the design of resistance and inductance parameters. Simultaneously, it optimizes parameter configuration through loss calculation, ensuring that the filter suppresses overvoltage at the motor end while possessing low loss and miniaturization characteristics. This solves the problems of difficulty in obtaining motor impedance, poor parameter matching, and inadequate loss control in traditional filter designs. It is suitable for electric drive systems such as servo motors, effectively protecting motor winding insulation and improving system operational stability.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a design method for an RL output filter for motor drive, comprising: Obtain cable-related parameters and motor-related parameters; The cable impedance is determined based on the relevant parameters of the cable; wherein, when determining the cable impedance, the system switching frequency, cable inductance, cable resistance and cable length are taken into account. Determine the motor impedance based on the determined cable impedance and relevant motor parameters; The impedance of the RL filter is determined based on the cable impedance, motor impedance, and impedance matching principles; the range of filter resistance parameters is determined based on the RL filter impedance. The range of filter inductance parameters is determined based on the filter resistance value and the filter cutoff frequency. Based on the range of filter resistance parameters and filter inductance parameters, and with filter power consumption as a constraint, determine the filter resistance and filter inductance values.

[0006] Furthermore, the cable impedance for: ; in, This refers to the system switching frequency; The inductance value per unit length of cable; The resistance value per unit length of cable; This refers to the cable length.

[0007] Furthermore, the motor impedance for: ; in, Voltage reflection coefficient; This represents the cable impedance.

[0008] Furthermore, the impedance of the RL filter is equal to the difference between the motor impedance and the cable impedance.

[0009] Furthermore, the filter resistance is not greater than the impedance of the RL filter.

[0010] Furthermore, the range of filter inductance parameters is determined based on the filter resistance value and the filter cutoff frequency, including: Determine the transfer function of the filter for: ; The cutoff frequency of the filter is obtained from the transfer function. for: ; Filter inductance parameters satisfy: ; in, This refers to the filter resistance value; is a complex variable in the Laplace transform.

[0011] Furthermore, the power consumption of the damping resistor is positively correlated with the resistance value, bus voltage, expected peak voltage at the motor terminal, and switching frequency. Under the premise of meeting various performance indicators, the damping resistor can be increased to reduce power loss. At the same time, the parameters of the filter inductor can be reduced to decrease the size, weight, and cost of the filter.

[0012] Furthermore, filter power consumption for: ; ; ; ; in, The power across the resistor; This refers to the voltage rise time. This refers to the system switching frequency; This represents the effective value of the voltage across the filter. The impedance of the RL filter; The impedance of the motor; The impedance of the cable; This represents the peak value of the motor terminal voltage. For filtering resistors; This refers to the cable length. Voltage reflection coefficient; This is the bus voltage.

[0013] Furthermore, the cable-related parameters include cable distribution parameters and cable length; the motor-related parameters include system switching frequency, voltage reflection coefficient, and bus voltage.

[0014] In a second aspect, the present invention also provides an RL output filter for motor drive, wherein the filter resistance value and filter inductance value are determined by the RL output filter design method for motor drive as described in the first aspect.

[0015] Thirdly, the present invention also provides a system for designing an RL output filter for motor drive, comprising: The data acquisition module is configured to acquire cable-related parameters and motor-related parameters. The cable impedance determination module is configured to determine the cable impedance based on relevant cable parameters; wherein, when determining the cable impedance, the system switching frequency, cable inductance, cable resistance, and cable length are taken into account. The motor impedance determination module is configured to determine the motor impedance based on the determined cable impedance and relevant motor parameters. The resistance parameter range determination module is configured to: determine the RL filter impedance based on the cable impedance, motor impedance, and impedance matching principles; and determine the filter resistance parameter range based on the RL filter impedance. The inductor parameter range determination module is configured to determine the filter inductor parameter range based on the filter resistance value and the filter cutoff frequency. The parameter design module is configured to determine the filter resistance and filter inductance values ​​based on the filter resistance parameter range and the filter inductance parameter range, with filter power consumption as a constraint.

[0016] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the design method for an RL output filter for motor drive described in the first aspect.

[0017] Fifthly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to implement the steps of the design method for an RL output filter for motor drive described in the first aspect.

[0018] In a sixth aspect, the present invention also provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the design method for an RL output filter for motor drive described in the first aspect.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention first determines the cable impedance based on relevant cable parameters, considering system switching frequency, cable inductance, cable resistance, and cable length. Then, based on the determined cable impedance and motor parameters, the motor impedance is determined. Next, the impedance of the RL filter is determined based on the cable impedance, motor impedance, and impedance matching principles. The range of filter resistance parameters is determined based on the RL filter impedance. The range of filter inductance parameters is determined based on the filter resistance value and filter cutoff frequency. Finally, based on the ranges of filter resistance and inductance parameters, and with filter power consumption as a constraint, the filter resistance and inductance values ​​are determined. By measuring cable parameters and estimating motor impedance, the basic system parameters are clarified. Then, based on impedance matching principles and high-frequency harmonic suppression requirements, the resistance and inductance parameters are designed. Simultaneously, parameter configuration is optimized through loss calculation, ensuring that the filter suppresses motor overvoltage while possessing low loss and miniaturization characteristics. This solves the problems of difficult motor impedance acquisition, poor parameter matching, and inadequate loss control in traditional filter designs. It is suitable for electric drive systems such as servo motors, effectively protecting motor winding insulation and improving system operational stability. Attached Figure Description

[0020] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0021] Figure 1 This is a schematic diagram of a motor drive system with an RL output filter according to an embodiment of the present invention, wherein, , , These are the filter input voltages, , , These are the filter output voltages; Figure 2 This is the motor terminal voltage waveform without the RL output filter in an embodiment of the present invention; Figure 3 This is the motor terminal voltage waveform with an RL output filter in an embodiment of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0024] Pulse-Width Modulation (PWM) is a highly effective technique for controlling analog circuits using the digital output of a microprocessor. By modulating the width of a series of pulses, the desired waveform (including shape and amplitude) can be obtained equivalently. In other words, by changing the proportion of conduction time to total time, i.e., the duty cycle, the voltage and frequency can be adjusted.

[0025] Example 1: In the field of electric drives, inverters using PWM technology are often connected to motors via long cables. The distributed inductance and capacitance of these cables form a distributed parameter network, which, under the influence of high-frequency pulse voltages, induces voltage wave reflections, leading to overvoltage spikes and high-frequency oscillations at the motor terminals that far exceed the bus voltage. This not only accelerates the aging of the motor winding insulation but may also cause breakdown faults, while simultaneously interfering with system control and reducing operational stability and efficiency. To address this issue, filters are typically installed on the inverter output side. Passive filters, with their simple structure and low cost, are widely used, primarily including LC, RLC, and RL filters. For example... Figure 1As shown, RL filters are widely used due to their simple structure (containing only one inductor and one resistor) and good high-frequency attenuation and impedance matching capabilities.

[0026] As described in the background section, traditional RL filter design methods have significant limitations. They often rely on simplified models or empirical formulas, failing to fully consider the combined effects of long cable distributed parameters and motor high-frequency impedance, resulting in poor impedance matching and limited suppression effectiveness. Resistor and inductor parameters are often designed in isolation, lacking system optimization. If the resistor is overemphasized for damping, it can lead to excessive losses and severe heat generation, requiring additional heat dissipation devices and increasing size and cost. Improperly designed inductors can make the filter bulky and potentially affect dynamic response. Furthermore, the motor impedance dynamically changes with frequency and load, making accurate measurement difficult and further increasing the matching difficulty of fixed-parameter filters. Existing filters generally face a dilemma in addressing long cable overvoltage problems: a balance between suppression effectiveness, operating losses, and size / cost.

[0027] To address the aforementioned issues, this embodiment provides a design method for an RL output filter for motor drives. Based on the actual parameters of the cable and motor, it effectively suppresses overvoltage while simultaneously optimizing filter loss and size, achieving a balance between performance, efficiency, and compactness. This solves the problems of difficulty in obtaining motor impedance, poor parameter matching, and excessive losses in traditional designs. The method includes the following steps: S1. Determine the cable impedance and motor impedance: S1.1 Determine the relevant parameters of the cable and motor: Determine the relevant parameters of the cable and motor, including cable distribution parameters, system switching frequency, voltage reflection coefficient, bus voltage, and cable length.

[0028] Cable distributed parameters refer to the basic physical quantities of cable electrical characteristics, which can include four parameters: cable resistance, cable inductance, cable capacitance, and cable conductance. Cable resistance represents the conductor's opposition to current flow, measured in Ω / km; resistance causes heat loss when current flows, and its value is related to the conductor material (such as copper or aluminum), cross-sectional area, and temperature. Cable inductance is caused by the magnetic field effect generated by alternating current, measured in mH / km; inductance affects the cable's voltage drop and reactive power, and is related to conductor arrangement, shielding layer, and laying method. Cable capacitance is formed by the electric field effect between conductors and between conductor and ground, measured in μF / km; capacitance determines the cable's charging current and energy storage capacity, and the insulation material (such as XLPE or PVC) and its thickness have a significant impact. Cable conductance corresponds to the leakage loss of the insulation medium or its conductivity to ground, measured in S / km (usually expressed as the reciprocal of insulation resistance); conductance reflects insulation performance, and the quality of the insulation material (such as the high insulation resistance of XLPE) directly affects its value. Optionally, parameters such as resistance, reactance, susceptance, and conductivity of the cable can be obtained by consulting the cable manual or by conducting tests, such as short-circuit tests and no-load tests.

[0029] The system switching frequency refers to the voltage pulse characteristic parameter of the inverter output, and its value is determined by the intersection of the modulating wave and the carrier wave. The system switching frequency directly affects the quality of the output voltage waveform and is related to technical indicators such as electromagnetic interference and component losses. Increasing the switching frequency can increase the number of pulses per unit cycle, improve the smoothness of the output current waveform, and reduce inductor current ripple and output voltage ripple. However, higher frequencies will lead to increased switching losses, enhanced electromagnetic interference, and higher requirements for heat dissipation design.

[0030] The voltage reflection coefficient of a motor is used to describe the voltage reflection phenomenon at the motor terminals, and its value ranges from -1 to +1. In practical applications, the voltage reflection coefficient is the basis for analyzing end-side overvoltage problems when a motor is driven by a long cable. By adjusting the inverter switching frequency, series reactors, or adding sinusoidal filters, the impedance matching state of the system can be changed, thereby effectively suppressing the reflection phenomenon, protecting the motor insulation, and improving system reliability.

[0031] Bus voltage refers to the voltage at the input terminal of the motor's main circuit, directly affecting motor performance and system stability. It can be AC ​​or DC. Bus voltage can be determined by looking up a table or by measurement.

[0032] S1.2 Determine the cable impedance: Determine the cable impedance based on the relevant cable parameters. , can be represented as: ; in, This refers to the system switching frequency; The inductance value per unit length of cable; The resistance value per unit length of cable; This refers to the cable length.

[0033] S1.3 Determine the motor impedance: Based on the determined cable impedance and relevant motor parameters, determine the motor impedance. , can be represented as: ; in, This is the voltage reflection coefficient.

[0034] S2. Determine the range of resistance parameters according to the impedance matching principle, and clarify that the resistance is the biggest influencing factor on the filter impedance.

[0035] S2.1 Determine the impedance of the RL filter: According to the impedance matching principle, the load impedance equals the transmission cable impedance; therefore, the RL filter impedance... It can be represented as: ; S2.2 Determine the filter resistor: The resistor plays a decisive role in the overall impedance of the filter; therefore, the filter resistor value must meet the following requirements: .

[0036] S3. Determine the inductor parameter range based on the filter cutoff frequency to filter out high-order harmonics contained in the inverter output voltage.

[0037] Filter transfer function Represented as: ; in, Let be a complex variable in the Laplace transform; the cutoff frequency of the filter can be obtained from the transfer function. for: ; In this embodiment, the cutoff frequency is the frequency point at which the output signal amplitude drops to half the input signal amplitude. This is a characteristic of the transfer function, and the cutoff frequency can be obtained from the transfer function. To achieve the best filtering effect, the filter inductor... The following conditions must be met: .

[0038] S4. Filter parameter optimization: Using filter power consumption as a constraint, optimize the design of resistance and inductance parameters.

[0039] RMS voltage across the filter during voltage rise It can be represented as: ; in, This represents the peak value of the motor terminal voltage.

[0040] Power on the resistor during voltage rise It can be represented as: ; voltage rise time It can be represented as: ; in, This is the bus voltage.

[0041] Power dissipation on resistor for: ; The power dissipation of the damping resistor is positively correlated with its resistance value, bus voltage, desired peak voltage at the motor terminals, and switching frequency. In practical design, the value of the damping resistor not only affects the peak voltage suppression effect but also closely relates to the system's heating conditions. Therefore, while meeting various performance indicators, the damping resistor should be increased as much as possible to reduce power loss; simultaneously, the parameters of the filter inductor should be minimized to effectively reduce the filter's size, weight, and cost, enabling it to better adapt to diverse design conditions. Therefore, the filter resistor... R f The value is Z f Filter inductor L f The value is .

[0042] This embodiment is particularly suitable for motor drive systems with long cables, effectively suppressing motor terminal overvoltage caused by voltage reflection. The method determines the range of filter resistor values ​​based on impedance matching principles, determines the range of inductor values ​​based on the filter cutoff frequency, and then optimizes the resistor and inductor parameters using power loss as a constraint. This method significantly reduces the peak voltage at the motor terminals, thereby protecting the insulation of the cable and motor windings.

[0043] Example 2: This embodiment provides an RL output filter for motor drive, wherein the filter resistance value and filter inductance value are determined by the RL output filter design method for motor drive as described in Embodiment 1.

[0044] like Figure 1The diagram shows a motor drive system with an RL output filter. To suppress voltage spikes at the motor terminals and control the filter size, the values ​​of the resistor and inductor are determined based on the principles of voltage reflection and impedance matching, using cable and motor parameters as inputs. While ensuring filtering effectiveness, the filter parameters are optimized under power consumption constraints, thereby effectively suppressing voltage spikes at the motor terminals. This includes: Determine the impedance parameters of the cable and motor, including cable distributed parameters, system switching frequency, reflection coefficient, bus voltage, and cable length.

[0045] The range of resistance parameters is determined based on the impedance matching principle, and the resistance is identified as the main factor affecting the filter impedance.

[0046] The range of inductor parameters is determined based on the filter cutoff frequency, and the influence of cable capacitance effect is suppressed by configuring the inductor.

[0047] With filter power consumption as a constraint, the resistance and inductance parameters are optimized to complete the parameter optimization of the RL filter.

[0048] Example 3: This embodiment provides a system for designing an RL output filter for motor drive, including: The data acquisition module is configured to acquire cable-related parameters and motor-related parameters. The cable impedance determination module is configured to determine the cable impedance based on relevant cable parameters; wherein, when determining the cable impedance, the system switching frequency, cable inductance, cable resistance, and cable length are taken into account. The motor impedance determination module is configured to determine the motor impedance based on the determined cable impedance and relevant motor parameters. The resistance parameter range determination module is configured to: determine the RL filter impedance based on the cable impedance, motor impedance, and impedance matching principles; and determine the filter resistance parameter range based on the RL filter impedance. The inductor parameter range determination module is configured to determine the filter inductor parameter range based on the filter resistance value and the filter cutoff frequency. The parameter design module is configured to determine the filter resistance and filter inductance values ​​based on the filter resistance parameter range and the filter inductance parameter range, with filter power consumption as a constraint.

[0049] The operating method of the system is the same as the RL output filter design method for motor drive in Embodiment 1, including: S1. Determine the cable impedance and motor impedance: S1.1 Determine the relevant parameters of the cable and motor: Determine the relevant parameters of the cable and motor, including cable distribution parameters, system switching frequency, voltage reflection coefficient, bus voltage, and cable length.

[0050] Cable distributed parameters refer to the basic physical quantities of cable electrical characteristics, which can include four parameters: cable resistance, cable inductance, cable capacitance, and cable conductance. Cable resistance represents the conductor's opposition to current flow, measured in Ω / km; resistance causes heat loss when current flows, and its value is related to the conductor material (such as copper or aluminum), cross-sectional area, and temperature. Cable inductance is caused by the magnetic field effect generated by alternating current, measured in mH / km; inductance affects the cable's voltage drop and reactive power, and is related to conductor arrangement, shielding layer, and laying method. Cable capacitance is formed by the electric field effect between conductors and between conductor and ground, measured in μF / km; capacitance determines the cable's charging current and energy storage capacity, and the insulation material (such as XLPE or PVC) and its thickness have a significant impact. Cable conductance corresponds to the leakage loss of the insulation medium or its conductivity to ground, measured in S / km (usually expressed as the reciprocal of insulation resistance); conductance reflects insulation performance, and the quality of the insulation material (such as the high insulation resistance of XLPE) directly affects its value. Optionally, parameters such as resistance, reactance, susceptance, and conductivity of the cable can be obtained by consulting the cable manual or by conducting tests, such as short-circuit tests and no-load tests.

[0051] The system switching frequency refers to the voltage pulse characteristic parameter of the inverter output, and its value is determined by the intersection of the modulating wave and the carrier wave. The system switching frequency directly affects the quality of the output voltage waveform and is related to technical indicators such as electromagnetic interference and component losses. Increasing the switching frequency can increase the number of pulses per unit cycle, improve the smoothness of the output current waveform, and reduce inductor current ripple and output voltage ripple. However, higher frequencies will lead to increased switching losses, enhanced electromagnetic interference, and higher requirements for heat dissipation design.

[0052] The voltage reflection coefficient of a motor is used to describe the voltage reflection phenomenon at the motor terminals, and its value ranges from -1 to +1. In practical applications, the voltage reflection coefficient is the basis for analyzing end-side overvoltage problems when a motor is driven by a long cable. By adjusting the inverter switching frequency, series reactors, or adding sinusoidal filters, the impedance matching state of the system can be changed, thereby effectively suppressing the reflection phenomenon, protecting the motor insulation, and improving system reliability.

[0053] Bus voltage refers to the voltage at the input terminal of the motor's main circuit, directly affecting motor performance and system stability. It can be AC ​​or DC. Bus voltage can be determined by looking up a table or by measurement.

[0054] S1.2 Determine the cable impedance: Determine the cable impedance based on the relevant cable parameters. , can be represented as: ; in, This refers to the system switching frequency; The inductance value per unit length of cable; The resistance value per unit length of cable; This refers to the cable length.

[0055] S1.3 Determine the motor impedance: Based on the determined cable impedance and relevant motor parameters, determine the motor impedance. , can be represented as: ; in, This is the voltage reflection coefficient.

[0056] S2. Determine the range of resistance parameters according to the impedance matching principle, and clarify that the resistance is the biggest influencing factor on the filter impedance.

[0057] S2.1 Determine the impedance of the RL filter: According to the impedance matching principle, the load impedance equals the transmission cable impedance; therefore, the RL filter impedance... It can be represented as: ; S2.2 Determine the filter resistor: The resistor plays a decisive role in the overall impedance of the filter; therefore, the filter resistor value must meet the following requirements: .

[0058] S3. Determine the inductor parameter range based on the filter cutoff frequency to filter out high-order harmonics contained in the inverter output voltage.

[0059] Filter transfer function Represented as: ; in, Let be a complex variable in the Laplace transform; the cutoff frequency of the filter can be obtained from the transfer function. for: ; To achieve the best filtering effect, the filter inductor... The following conditions must be met: .

[0060] S4. Filter parameter optimization: Using filter power consumption as a constraint, optimize the design of resistance and inductance parameters.

[0061] RMS voltage across the filter during voltage rise It can be represented as: ; in, This represents the peak value of the motor terminal voltage.

[0062] Power on the resistor during voltage rise It can be represented as: ; voltage rise time It can be represented as: ; in, This is the bus voltage.

[0063] Power dissipation on resistor for: ; The power dissipation of the damping resistor is positively correlated with its resistance value, bus voltage, desired peak voltage at the motor terminals, and switching frequency. In practical design, the value of the damping resistor not only affects the peak voltage suppression effect but also closely relates to the system's heating conditions. Therefore, while meeting various performance indicators, the damping resistor should be increased as much as possible to reduce power loss; simultaneously, the parameters of the filter inductor should be minimized to effectively reduce the filter's size, weight, and cost, enabling it to better adapt to diverse design conditions. Therefore, the filter resistor... R f The value is Z f Filter inductor L f The value is .

[0064] Example 4: This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the RL output filter design method for motor drive described in Embodiment 1.

[0065] Example 5: This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, it implements the steps of the RL output filter design method for motor drive described in Embodiment 1.

[0066] Example 6: This embodiment provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the steps of the RL output filter design method for motor drive described in Embodiment 1.

[0067] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A design method for an RL output filter for motor drive, characterized in that, include: Obtain cable-related parameters and motor-related parameters; The cable impedance is determined based on the relevant parameters of the cable; wherein, when determining the cable impedance, the system switching frequency, cable inductance, cable resistance and cable length are taken into account. Determine the motor impedance based on the determined cable impedance and relevant motor parameters; The impedance of the RL filter is determined based on the cable impedance, motor impedance, and impedance matching principles; the range of filter resistance parameters is determined based on the RL filter impedance. The range of filter inductance parameters is determined based on the filter resistance value and the filter cutoff frequency. Based on the range of filter resistance parameters and filter inductance parameters, and with filter power consumption as a constraint, determine the filter resistance and filter inductance values.

2. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The cable impedance for: ； in, This refers to the system switching frequency; The inductance value per unit length of cable; The resistance value per unit length of cable; This refers to the cable length.

3. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The motor impedance for: ； in, Voltage reflection coefficient; This represents the cable impedance.

4. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The impedance of the RL filter is equal to the difference between the motor impedance and the cable impedance.

5. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The filter resistance is not greater than the impedance of the RL filter.

6. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The range of filter inductor parameters is determined based on the filter resistance value and the filter cutoff frequency, including: Determine the transfer function of the filter for: ； The cutoff frequency of the filter is obtained from the transfer function. for: ； Filter inductance parameters satisfy: ； in, This refers to the filter resistance value; is a complex variable in the Laplace transform.

7. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The power consumption of the damping resistor is positively correlated with the resistance value, bus voltage, expected peak voltage at the motor terminal, and switching frequency. Under the premise of meeting various performance indicators, the damping resistor is increased to reduce power loss. At the same time, the parameters of the filter inductor are reduced to decrease the size, weight, and cost of the filter.

8. The design method for an RL output filter for motor drive as described in claim 7, characterized in that, Filter power consumption for: ； ； ； ； in, The power across the resistor; This refers to the voltage rise time. This refers to the system switching frequency; This represents the effective value of the voltage across the filter. The impedance of the RL filter; The impedance of the motor; The impedance of the cable; This represents the peak value of the motor terminal voltage. For filtering resistors; This refers to the cable length. Voltage reflection coefficient; This is the bus voltage.

9. The design method for an RL output filter for motor drive as described in claim 1, characterized in that, The cable-related parameters include cable distribution parameters and cable length; the motor-related parameters include system switching frequency, voltage reflection coefficient, and bus voltage.

10. An RL output filter for motor drive, characterized in that, The filter resistance and filter inductance values ​​in the filter are determined by the design method for an RL output filter for motor drive as described in any one of claims 1-9.

11. A design system for an RL output filter for motor drive, characterized in that, include: The data acquisition module is configured to acquire cable-related parameters and motor-related parameters. The cable impedance determination module is configured to determine the cable impedance based on relevant cable parameters; wherein, when determining the cable impedance, the system switching frequency, cable inductance, cable resistance, and cable length are taken into account. The motor impedance determination module is configured to determine the motor impedance based on the determined cable impedance and relevant motor parameters. The resistance parameter range determination module is configured to: determine the RL filter impedance based on the cable impedance, motor impedance, and impedance matching principles; and determine the filter resistance parameter range based on the RL filter impedance. The inductor parameter range determination module is configured to determine the filter inductor parameter range based on the filter resistance value and the filter cutoff frequency. The parameter design module is configured to determine the filter resistance and filter inductance values ​​based on the filter resistance parameter range and the filter inductance parameter range, with filter power consumption as a constraint.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the steps of the RL output filter design method for motor drive as described in any one of claims 1-9.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the program, it implements the steps of the RL output filter design method for motor drive as described in any one of claims 1-9.

14. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the design method for an RL output filter for motor drive as described in any one of claims 1-9.

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