CN113420398A - Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system - Google Patents

Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system Download PDF

Info

Publication number
CN113420398A
CN113420398A CN202110690297.9A CN202110690297A CN113420398A CN 113420398 A CN113420398 A CN 113420398A CN 202110690297 A CN202110690297 A CN 202110690297A CN 113420398 A CN113420398 A CN 113420398A
Authority
CN
China
Prior art keywords
cable
frequency
resistance
model
circuit impedance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110690297.9A
Other languages
Chinese (zh)
Inventor
陈国柱
徐昌汉
王磊
王征标
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hangzhou Hechang Electronic Technology Co ltd
Zhejiang University ZJU
Original Assignee
Hangzhou Hechang Electronic Technology Co ltd
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hangzhou Hechang Electronic Technology Co ltd, Zhejiang University ZJU filed Critical Hangzhou Hechang Electronic Technology Co ltd
Priority to CN202110690297.9A priority Critical patent/CN113420398A/en
Publication of CN113420398A publication Critical patent/CN113420398A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/18—Network design, e.g. design based on topological or interconnect aspects of utility systems, piping, heating ventilation air conditioning [HVAC] or cabling
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/30—Circuit design
    • G06F30/39—Circuit design at the physical level
    • G06F30/398—Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2113/00—Details relating to the application field
    • G06F2113/16—Cables, cable trees or wire harnesses

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • Evolutionary Computation (AREA)
  • Computational Mathematics (AREA)
  • Pure & Applied Mathematics (AREA)
  • Mathematical Optimization (AREA)
  • Mathematical Analysis (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

The invention discloses a comprehensive high-frequency modeling method for a cable in a long-line driving system of a variable-frequency motor, which considers that the resistance of the cable at the self-resonant frequency greatly affects a model, so that the resistance at the self-resonant frequency is corrected, and the difficulty of resistance modeling in the cable model can be solved. The invention identifies the model parameters through the DM and CM impedance characteristics measured by the impedance analyzer, gives an analytic design equation, establishes the model of the whole driving system by combining the simplified inverter model and the simplified motor model, predicts the DM overvoltage and the CM current, has better fit between the simulation result and the experimental waveform and shows the effectiveness of the model. In addition, the high-frequency effect is considered in the cable high-frequency model, the resonance resistance parameters are introduced, the model parameter solving is simple, and the solution can be carried out only by knowing the impedance of the tested cable at the low frequency band, the resonance position and the high frequency band.

Description

Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system
Technical Field
The invention belongs to the technical field of motor system simulation analysis, and particularly relates to a comprehensive high-frequency modeling method for a cable in a long-line driving system of a variable-frequency motor.
Background
Pulse width modulated voltage source inverters (PWM-VSIs) play an important role in speed regulated drive (ASD) systems, making drive applications more efficient. New power semiconductor devices with high switching speeds increase the power density for ASD applications, but electromagnetic interference (EMI) problems associated with high frequencies also arise. The high frequency problem is exacerbated if the inverter is connected between the motor by long cables, since voltage reflections occur along the cables due to impedance mismatch between the cables and the motor, resulting in twice or more dc bus voltage at the motor end, which may damage the insulation of the cables and the motor. Furthermore, applying a high dv/dt on the parasitic capacitance of the cable generates high frequency currents, which may lead to drive system failure. In addition to the insulation problems of the motor, the high frequency currents caused by high dv/dt also shorten the life of the motor. In order to analyze the influence caused by the long-line cable, the cable needs to be modeled, so that the waveforms such as the voltage at the tail end of the cable are obtained through simulation, and the influence of the waveforms on the motor driving system is evaluated.
In the modeling of a long-line drive system, the cable model is the most critical part and needs to be consistent with the actual high-frequency response. Of course, researchers are also working their efforts to build accurate models of the inverter and motor, which are two additional parts of a simplified drive system. The inverter is usually seen as a trapezoidal or parabolic voltage source, and its internal impedance is sometimes considered, but because its internal impedance is negligible compared to the cable resistance. The modeling of the motor can also adopt a method similar to a cable to obtain a more accurate model, but the motor model has very limited function in a long-line driving system, and particularly for a low-power motor, the high-frequency model can be simplified into an RL series model or even an open circuit; so far, a long-line driving model taking a cable model as a core is completely established. The measured motor parameters are fitted with rational functions, and time domain and frequency domain motor models are proposed in the literature [ M.Schinkel, S.Weber, S.Guttowski, W.John and H.Reichl, "effective HF modeling and model parameter of indication mechanisms for time and frequency domain relationships," two-First annular Applied Power Electronics reference and Exposion, 2006.APEC'06., Dallas, TX,2006, pp.6 ]. With respect to the cable model, we know that the low frequency model is not sufficient to analyze the high frequency phenomena occurring in long cable drive systems. The documents [ F.A. Moreira, J.R. Marti, L.C. Zantetta, "tension technologies Applied to the Transmission Simulation of Transmission Lines Using the Z-Line Model", Transmission & Distribution reference and Exposure: Latin America 2006, TDC'06.IEEE/PES, pp.1-6,2006] fit cable parameters related to frequency Using mathematical models, but the mathematical derivation is abstract. Currently, lumped parameter models are widely used, and are classified according to the betweenness of the models, including multi-order and second-order. The model based on time domain characteristics is widely accepted, while the cable model based on frequency domain is another method worth exploring, and has the advantages of short simulation time and difficult construction of an inverter or a harmonic voltage source.
For a long-line circuit model, a PI type model is generally adopted as a basic long-line cable model, and although the high-frequency resonance characteristic of the cable can be reflected, the three high-frequency characteristics of the cable, namely a high-frequency skin effect, a proximity effect and a dielectric loss, are not considered. Furthermore, in current cable models, cable resistance generally cannot be accurately modeled over the full frequency domain in the cable model compared to cable inductance capacitance, because resistance is small in high frequency impedance and non-linearity is large, which is inconvenient for modeling.
Disclosure of Invention
In view of the above, the invention provides a comprehensive high-frequency modeling method for a cable in a long-line driving system of a variable frequency motor, and the difficulty of resistance modeling in a cable model can be solved by correcting the resistance at the self-resonant frequency in consideration of the fact that the resistance of the cable at the self-resonant frequency greatly affects the model.
A comprehensive high-frequency modeling method for a cable in a long-line driving system of a variable-frequency motor comprises the following steps:
(1) establishing and improving a long-line cable model of the system;
(2) calculating and determining the length of the cable to be measured;
(3) calculating the resonant frequency of the cable;
(4) for a specific cable in the system, measuring an open-circuit impedance characteristic curve and a short-circuit impedance characteristic curve of a section of the cable by using an impedance analyzer;
(5) calculating and determining differential mode parameters of the long-line cable model according to the impedance characteristic curve and the resonance frequency;
(6) and calculating and determining the common mode parameters of the long-line cable model according to the impedance characteristic curve and the resonance frequency.
Further, the long-line cable model in the step (1) comprises a resistor Rs1Resistance Rs2Resistance Δ RsResistance Δ RpResistance Rp1Resistance Rp2Capacitor Cp1Capacitor Cp2Inductor Ls1And an inductance Ls2Wherein: resistance Rs1As the starting end of the cable (i.e., the end closer to the inverter side), resistor Rs1Another end of (1) and an inductor Ls1Is connected to one end of an inductor Ls1Another terminal of (1) and a resistor Rs2And an inductor Ls2Is connected to one end of a resistor Rs2Another terminal of (1) and a resistance DeltaRsAnd an inductor Ls2Is connected to the other end of the resistor Delta RsAnother terminal of (1) and a resistance DeltaRpOne terminal of (1), resistance Rp1One terminal of (1), a capacitor Cp1One terminal of and a capacitor Cp2Is connected to and serves as the end of the cable (i.e. the end closer to the motor side), the capacitor Cp2Another terminal of (1) and a resistor Rp2Is connected to one end of a resistor Rp2Another terminal of (1) and a resistance DeltaRpAnother terminal of (1), a resistor Rp1Another terminal of (1) and a capacitor Cp1Is connected to ground, a capacitor Cp2And a resistance Rp2Forming a resistor R as a parallel branchs2And an inductance Ls2Forming a resistor DeltaR as a series branchsAnd resistance Δ RpTo form the supplementary branch.
Further, the calculation and determination standard of the cable length to be measured in the step (2) is as follows:
Figure BDA0003126420870000031
wherein: ltestFor the length of cable to be measured, fmaxIs the maximum measurement frequency, L, of the impedance analyzer0Is the inductance per unit length of the cable, C0Is the capacitance per unit length of the cable, epsilonrIs the relative dielectric constant, and c is the speed of light.
Further, in the step (3), calculating the resonant frequency of the cable by the following formula;
Figure BDA0003126420870000032
wherein: f. ofNaIs the resonant frequency of the cable, L is the actual length of the cable, L0Is the inductance per unit length of the cable, C0Is the capacitance per unit length of the cable.
Further, in the step (5), the differential mode parameters of the long-line cable model are calculated and determined through the following formula;
Ls1+Ls2＝|ZSC-LF|[2πfLF]-1
Ls1＝|ZSC-HF|[2πfHF]-1
Rs1＝RSC-DC
Rs1+Rs2＝|ZSC-HF|cosθSC-HF
ΔRs＝|ZSC-Na|cosθSC-Na-Real[Rs1+j2πfNaLs1+Rs2//(j2πfNaLs2)]
Cp1+Cp2＝[|ZOC-LF|(2πfLF)]-1
Cp1＝[|ZOC-HF|(2πfHF)]-1
Rp1＝ROC-DC
Rp1//Rp2＝|ZOC-HF|[cos(-θOC-HF)]-1
(ΔRp)-1＝Real[(|ZOC-Na|∠θOC-Na)-1]-Real[(Rp1)-1+j2πfNaCp1+(Rp2+(j2πfNaCp2)-1)-1]
wherein: l iss1And Ls2Are respectively an inductance Ls1And Ls2The inductance value, | ZSC-LFL is the low-frequency-section differential-mode short-circuit impedance amplitude of the cable, fLFFor low band frequencies, | ZSC-HFI is the high-frequency section differential mode short circuit impedance amplitude of the cable, fHFAt a high band frequency, Rs1And Rs2Are respectively a resistance Rs1And Rs2Resistance value of RSC-DCIs the differential mode short-circuit DC resistance of the cable, thetaSC-HFIs the high-frequency section differential mode short-circuit impedance argument, Delta R, of the cablesAnd Δ RpRespectively, resistance DeltaRsAnd Δ RpIs measured, | ZSC-NaI is the differential mode short circuit impedance at resonance of the cable, thetaSC-NaIs the resonant differential mode short circuit impedance amplitude angle of the cable, Real [ ]]Is a function of the real part, fNaIs the resonant frequency of the cable, j is the imaginary unit, Cp1And Cp2Are respectively a capacitor Cp1And Cp2Capacitance value, | ZOC-LFI is the low-frequency section differential mode open-circuit impedance amplitude of the cable, | ZOC-HFI is the high-frequency section differential mode open-circuit impedance amplitude of the cable, ROC-DCIs the differential mode open-circuit DC resistance of the cable, thetaOC-HFIs the high-frequency section difference mode open-circuit impedance argument, | Z of the cableOC-NaI is the differential mode open-circuit impedance at resonance of the cable, Rp1And Rp2Are respectively a resistance Rp1And Rp2The resistance value of (a) is set,|ZOC-Na|∠θOC-Nai.e. representing the complex plane at | ZOC-NaI is the modulus and the angle is thetaOC-NaComplex number of (a), thetaOC-NaFor the amplitude of the differential mode open circuit impedance at resonance of the cable,// denotes the parallel operator (here, the resistance is shown in parallel with the inductance).
Further, in the step (6), common mode parameters of the long-line cable model are calculated and determined through the following formula;
Ls1+Ls2＝|ZSD-LF|[2πfLF]-1
Ls1＝|ZSD-HF|[2πfHF]-1
Rs1＝RSD-DC
Rs1+Rs2＝|ZSD-HF|cosθSD-HF
ΔRs＝|ZSD-Na|cosθSD-Na-Real[Rs1+j2πfNaLs1+Rs2//(j2πfNaLs2)]
Cp1+Cp2＝[ZOD-LF|(2πfLF)]-1
Cp1＝[ZOD-HF|(2πfHF)]-1
Rp1＝ROD-DC
Rp1//Rp2＝|ZOD-HF|[cos(-θOD-HF)]-1
(ΔRp)-1＝Real[(|ZOD-Na|∠θOD-Na)-1]-Real[(Rp1)-1+j2πfNaCp1+(Rp2+(j2πfNaCp2)-1)-1]
wherein: l iss1And Ls2Are respectively an inductance Ls1And Ls2The inductance value, | ZSD-LFI is the low-frequency common-mode short-circuit impedance amplitude of the cable, fLFFor low band frequencies, | ZSD-HFI is the high-frequency common-mode short-circuit impedance amplitude of the cable, fHFAt a high band frequency, Rs1And Rs2Are respectively a resistance Rs1And Rs2Resistance value of RSD-DCIs the common-mode short-circuit DC resistance of the cable, thetaSD-HFIs the high-frequency common-mode short-circuit impedance argument, Delta R, of the cablesAnd Δ RpRespectively, resistance DeltaRsAnd Δ RpIs measured, | ZSD-NaI is the common mode short circuit impedance at the resonance of the cable, θSD-NaIs the common mode short circuit impedance amplitude angle at the resonance of the cable, Real]Is a function of the real part, fNaIs the resonant frequency of the cable, j is the imaginary unit, Cp1And Cp2Are respectively a capacitor Cp1And Cp2Capacitance value, | ZOD-LFI is the low-frequency common-mode open-circuit impedance amplitude of the cable, | ZOD-HFI is the high-frequency common-mode open-circuit impedance amplitude of the cable, ROD-DCIs the common-mode open-circuit DC resistance of the cable, thetaOD-HFIs the high-frequency common-mode open-circuit impedance argument, | Z of the cableOD-NaI is the common-mode open-circuit impedance at resonance of the cable, Rp1And Rp2Are respectively a resistance Rp1And Rp2Is measured, | ZOD-Na|∠θOD-NaI.e. representing the complex plane at | ZOD-NaI is the modulus and the angle is thetaOD-NaComplex number of (a), thetaOD-NaIs the common mode open circuit impedance argument at resonance of the cable,// denotes the parallel operator (here, resistance in parallel with inductance).
The invention analyzes the importance of the high-frequency resistance of the cable, which is a factor easy to ignore in the cable modeling process, identifies model parameters through the DM and CM impedance characteristics measured by the impedance analyzer, and provides an analytic design equation. By predicting the DM overvoltage and the CM current, the simulation result is well matched with the experimental waveform, and the effectiveness of the model is shown. Meanwhile, the high-frequency effect is considered in the cable high-frequency model, and the resonance resistance parameters are introduced, so that the model parameter solution is simpler, and the solution can be realized only by knowing the impedance of the tested cable at the low frequency band, the resonance position and the high frequency band.
Drawings
Fig. 1(a) is a schematic structural diagram of a cable PI model.
Fig. 1(b) is a schematic structural diagram of an improved cable model according to the present invention.
Fig. 2(a) is a schematic diagram of a cable differential mode short circuit test connection.
Fig. 2(b) is a schematic diagram of a cable differential mode open circuit test connection.
Fig. 2(c) is a schematic diagram of a cable common mode short circuit test connection.
Fig. 2(d) is a schematic diagram of a cable common mode open test connection.
Fig. 3(a) is an equivalent circuit diagram of the series branch circuit of the cable model in the low frequency band.
Fig. 3(b) is an equivalent circuit diagram of the series branch circuit of the high frequency band of the cable model of the present invention.
Fig. 3(c) is a series branch equivalent circuit diagram at the cable model resonance of the present invention.
Fig. 4(a) is a schematic diagram of the amplitude and amplitude curves of the differential-mode short-circuit impedance of the cable.
Fig. 4(b) is a schematic diagram of the amplitude and amplitude curve of the differential-mode open-circuit impedance of the cable.
Fig. 5(a) is a schematic diagram of a simulation waveform of a cable initial end line voltage based on an improved model of the invention.
FIG. 5(b) is a waveform diagram of a cable end line voltage simulation based on the improved model of the present invention.
Fig. 6 is a schematic diagram of a simulation waveform of a terminal line voltage of a cable based on a PI model and a TLOSSY model.
Detailed Description
In order to more specifically describe the present invention, the following detailed description is provided for the technical solution of the present invention with reference to the accompanying drawings and the specific embodiments.
The present invention takes into account the high frequency characteristics of the cable and the resistance at the resonance frequency, and provides a new model (as shown in fig. 1 (b)) based on the basic PI model (as shown in fig. 1 (a)), which is suitable for both differential and common mode equivalent circuits. Compared with the original PI model, the improved model adds parallel branch (R)p2-Cp2) Is a branch, series branch (R) taking into account the increase in dielectric losss2-Ls2) Is a branch circuit which takes the skin effect and the proximity effect into consideration and supplements the branch circuit (delta R)s-ΔRp) Is to the series resistance at the resonance pointAnd correction of the parallel resistance value.
(1) And calculating the length of the tested cable.
For a specific cable, in order to calculate the parameters of the model proposed by the invention, it is necessary to measure the open-circuit and short-circuit impedance characteristic curves of one section of the cable by using an impedance analyzer, and the length l of the measured cabletestDependent on the maximum measuring frequency fmaxThe formula is as follows:
Figure BDA0003126420870000071
in the above formula: l is0Representing the inductance per unit length of the cable, C0Representing the capacitance per unit length of the cable, epsilonrFor the relative dielectric constant, c is the speed of light, i.e., c is 299792458 m/s.
(2) Cable self resonant frequency.
The resistance of the cable at the self-resonant frequency has a great influence on the model and determines the damping effect of overvoltage of the cable, and the resonant frequency is calculated as follows:
Figure BDA0003126420870000072
in the above formula: l represents the actual length of the cable; although the frequency spectrum of the PWM voltage at the beginning end of the cable in the motor driving system is rich, the resonant frequency of the voltage at the end of the cable is consistent with the self-resonant frequency of the cable, which is also the reason that the resistance value at the self-resonant frequency has a large influence on the overvoltage waveform of the cable.
(3) And calculating model parameters.
The differential mode of the cable is similar to the common mode model parameter calculation method, and taking the differential mode model parameter calculation of the cable as an example, the differential mode short-circuit impedance and the open-circuit impedance of the cable are measured firstly, and the measurement mode is shown in fig. 2(a) and fig. 2 (b).
For the differential mode short circuit impedance, the low-frequency band impedance (| Z) needs to be measuredSC-LF|,θSC-LF,fLF) High band impedance (| Z)SC-HF|,θSC-HF,fHF) With impedance at resonance (| Z)SC-Na|,θSC-Na,fNa) And then combining the cable improvement model to obtain the equivalent circuit of the series branch at the low frequency band, the high frequency band and the resonance frequency, as shown in fig. 3(a) -3 (c).
Finally, the calculation formula of the parameters of the series branch can be obtained by combining the measured impedance value and the equivalent circuit of the series branch as follows:
Ls1+Ls2＝|ZSC-LF|[2πfLF]-1 (3)
Ls1＝|ZSC-HF|[2πfHF]-1 (4)
Rs1＝RSC-DC (5)
Rs1+Rs2＝|ZSC-HF|cosθSC-HF (6)
ΔRs＝|ZSC-Na|cosθSC-Na-Real[Rs1+j2πfNaLs1+Rs2//(j2πfNaLs2)] (7)
similarly, for the differential mode open circuit impedance, impedance values at low frequency band, high frequency band and resonant frequency of the differential mode open circuit impedance are measured, and parallel branch parameters are calculated by combining parallel branch equivalent circuits at different frequencies in the cable improvement model, so that a parallel branch parameter calculation formula is obtained as follows:
Cp1+Cp2＝[ZOC-LF|(2πfLF)]-1 (8)
Cp1＝[ZOC-HF|(2πfHF)]-1 (9)
Rp1＝ROC-DC (10)
Rp1//Rp2＝|ZOC-HF|[cos(-θOC-HF)]-1 (11)
(ΔRp)-1＝Real(ZOC-Na|∠θOC-Na)-1-Real[(Rp1)-1+j2πfNaCp1+(Rp2+(j2πfNaCp2)-1)-1] (12)
also, common mode equivalent circuit parameters were calculated by testing the common mode short and open circuit impedances of the cables and the equivalent circuits of the cable improvement models, as shown in fig. 2(c) and 2 (d).
(4) And (5) modeling effect.
Table 1 shows the cable model parameters of the unshielded waterproof PVC four-core cable (copper core diameter 2mm) measured in practice, and in order to verify the accuracy of the cable model, the differential mode impedance curve may be taken as an example: the calculated cable model simulates the differential mode impedance curve of a 200m cable and is compared with the actual measured value, and the comparison result is shown in fig. 4(a) and 4(b), and the simulated value is basically consistent with the actual value.
TABLE 1
Figure BDA0003126420870000081
Figure BDA0003126420870000091
In order to further verify the accuracy of the designed cable model, the initial and terminal voltages of the cable can be simulated, therefore, modeling of the inverter and the motor is also needed, the model of the inverter can be equivalent to a trapezoidal wave voltage source with internal resistance, the internal resistance of the inverter can be neglected compared with the resistance of the cable, the modeling of the motor can obtain a more accurate model by adopting a method similar to the cable, only the function of the motor model in a long-line driving system is very limited, and particularly for a low-power motor, the high-frequency model can be simplified into an RL series model or even an open circuit. So far, a long-line driving model with a cable model as a core is completely established, and accordingly, simulated cable start and end overvoltage waveforms are shown in fig. 5(a) and 5(b), wherein the amplitude of the waveform at the cable start is 380V, and the amplitude of the waveform at the cable end reaches 850V due to the action of the long-line cable. And comparing the simulation result of the invention based on the improved cable model with the simulation waveforms of the PI type model in MATLAB and the TLOSSY model in Pspice, as shown in FIG. 6, it is obvious that the accuracy of the designed cable model is higher.
The invention provides two high-frequency cable models to improve the frequency dependence characteristic of the power cable, and compares the two models, and the result shows that the high-frequency cable model has similar or even better performance than the proposed inverter modeling circuit, but takes more time to calculate and simulate. On the basis of providing an analytical design equation, the method evaluates the extracted model parameters, establishes a whole cable model, and verifies the effectiveness of the model through an actual 200m power cable. In order to verify the simulation results of the DM overvoltage and the CM current based on the long-wire cable drive system model, the frequency converter and the motor model, the present invention performed an experiment on a 750W test platform, and compared the simulation results of the proposed model with the experiment results.
The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. It will be readily apparent to those skilled in the art that various modifications to the above-described embodiments may be made, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.

Claims (6)

1. A comprehensive high-frequency modeling method for a cable in a long-line driving system of a variable-frequency motor comprises the following steps:
(1) establishing and improving a long-line cable model of the system;
(2) calculating and determining the length of the cable to be measured;
(3) calculating the resonant frequency of the cable;
(4) for a specific cable in the system, measuring an open-circuit impedance characteristic curve and a short-circuit impedance characteristic curve of a section of the cable by using an impedance analyzer;
(5) calculating and determining differential mode parameters of the long-line cable model according to the impedance characteristic curve and the resonance frequency;
(6) and calculating and determining the common mode parameters of the long-line cable model according to the impedance characteristic curve and the resonance frequency.
2. The integrated high frequency modeling method of claim 1, wherein: the long-line cable model in the step (1) comprises a resistor Rs1Resistance Rs2Resistance Δ RsResistance Δ RpResistance Rp1Resistance Rp2Capacitor Cp1Capacitor Cp2Inductor Ls1And an inductance Ls2Wherein: resistance Rs1One end of (2) is used as the initial end of the cable, and the resistor Rs1Another end of (1) and an inductor Ls1Is connected to one end of an inductor Ls1Another terminal of (1) and a resistor Rs2And an inductor Ls2Is connected to one end of a resistor Rs2Another terminal of (1) and a resistance DeltaRsAnd an inductor Ls2Is connected to the other end of the resistor Delta RsAnother terminal of (1) and a resistance DeltaRpOne terminal of (1), resistance Rp1One terminal of (1), a capacitor Cp1One terminal of and a capacitor Cp2Connected at one end and serving as the end of the cable, capacitor Cp2Another terminal of (1) and a resistor Rp2Is connected to one end of a resistor Rp2Another terminal of (1) and a resistance DeltaRpAnother terminal of (1), a resistor Rp1Another terminal of (1) and a capacitor Cp1Is connected to ground, a capacitor Cp2And a resistance Rp2Forming a resistor R as a parallel branchs2And an inductance Ls2Forming a resistor DeltaR as a series branchsAnd resistance Δ RpTo form the supplementary branch.
3. The integrated high frequency modeling method of claim 1, wherein: the calculation and determination standard of the length of the cable to be measured in the step (2) is as follows:
Figure FDA0003126420860000011
wherein: ltestFor the length of cable to be measured, fmaxIs the maximum measurement frequency, L, of the impedance analyzer0Is the inductance per unit length of the cable, C0Is the capacitance per unit length of the cable, epsilonrIs the relative dielectric constant, and c is the speed of light.
4. The integrated high frequency modeling method of claim 1, wherein: calculating the resonant frequency of the cable by the following formula in the step (3);
Figure FDA0003126420860000021
wherein: f. ofNaIs the resonant frequency of the cable, L is the actual length of the cable, L0Is the inductance per unit length of the cable, C0Is the capacitance per unit length of the cable.
5. The integrated high frequency modeling method of claim 1, wherein: in the step (5), the differential mode parameters of the long-line cable model are calculated and determined through the following formula;
Ls1+Ls2＝|ZSC-LF|[2πfLF]-1
Ls1＝|ZSC-HF|[2πfHF]-1
Rs1＝RsC-DC
Rs1+Rs2＝|ZSC-HF|cosθSC-HF
ΔRs＝|ZSC-Na|cosθSC-Na-Real[Rs1+j2πfNaLs1+Rs2//(j2πfNaLs2)]
Cp1+Cp2＝[|ZOC-LF|(2πfLF)]-1
Cp1＝[|ZOC-HF|(2πfHF)]-1
Rp1＝ROC-DC
Rp1//Rp2＝|ZOC-HF|[cos(-θOC-HF)]-1
(ΔRp)-1＝Real[(|ZOC-Na|∠θOC-Na)-1]-Real[(Rp1)-1+j2πfNaCp1+(Rp2+(j2πfNaCp2)-1)-1]
wherein: l iss1And Ls2Are respectively an inductance Ls1And Ls2The inductance value, | ZSC-LFL is the low-frequency-section differential-mode short-circuit impedance amplitude of the cable, fLFFor low band frequencies, | ZSC-HFI is the high-frequency section differential mode short circuit impedance amplitude of the cable, fHFAt a high band frequency, Rs1And Rs2Are respectively a resistance Rs1And Rs2Resistance value of RSC-DCIs the differential mode short-circuit DC resistance of the cable, thetaSC-HFIs the high-frequency section differential mode short-circuit impedance argument, Delta R, of the cablesAnd Δ RpRespectively, resistance DeltaRsAnd Δ RpIs measured, | ZSC-NaI is the differential mode short circuit impedance at resonance of the cable, thetaSC-NaIs the resonant differential mode short circuit impedance amplitude angle of the cable, Real [ ]]Is a function of the real part, fNaIs the resonant frequency of the cable, j is the imaginary unit, Cp1And Cp2Are respectively a capacitor Cp1And Cp2Capacitance value, | ZOC-LFI is the low-frequency section differential mode open-circuit impedance amplitude of the cable, | ZOC-HFI is the high-frequency section differential mode open-circuit impedance amplitude of the cable, ROC-DCIs the differential mode open-circuit DC resistance of the cable, thetaOC-HFIs the high-frequency section difference mode open-circuit impedance argument, | Z of the cableOC-NaI is the differential mode open-circuit impedance at resonance of the cable, Rp1And Rp2Are respectively a resistance Rp1And Rp2Is measured, | ZOC-Na|∠θOC-NaI.e. representing the complex plane at | ZOC-NaI is the modulus and the angle is thetaOC-NaComplex number of (a), thetaOC-NaFor the amplitude of the differential mode open circuit impedance at resonance of the cable,// denotes the parallel operator.
6. The integrated high frequency modeling method of claim 1, wherein: in the step (6), common mode parameters of the long-line cable model are calculated and determined through the following formula;
Ls1+Ls2＝|ZSD-LF|[2πfLF]-1
Ls1＝|ZSD-HF|[2πfHF]-1
Rs1＝RsD-DC
Rs1+Rs2＝|ZSD-HF|cosθSD-HF
ΔRs＝|ZSD-Na|cosθSD-Na-Real[Rs1+j2πfNaLs1+Rs2//(j2πfNaLs2)]
Cp1+Cp2＝[|ZOD-LF|(2πfLF)]-1
Cp1＝[|ZOD-HF|(2πfHF)]-1
Rp1＝ROD-DC
Rp1//Rp2＝|ZOD-HF|[coS(-θOD-HF)]-1
(ΔRp)-1＝Real[(|ZOD-Na|∠θOD-Na)-1]-Real[(Rp1)-1+j2πfNaCp1+(Rp2+(j2πfNaCp2)-1)-1]
wherein: l iss1And Ls2Are respectively an inductance Ls1And Ls2The inductance value, | ZSD-LFI is the low-frequency common-mode short-circuit impedance amplitude of the cable, fLFFor low band frequencies, | ZSD-HFI is the high-frequency common-mode short-circuit impedance amplitude of the cable, fHFAt a high band frequency, Rs1And Rs2Are respectively a resistance Rs1And Rs2Resistance value of RSD-DCIs the common-mode short-circuit DC resistance of the cable, thetaSD-HFIs the high-frequency common-mode short-circuit impedance argument, Delta R, of the cablesAnd Δ RpRespectively, resistance DeltaRsAnd Δ RpIs measured, | ZSD-NaI is the common mode short circuit impedance at the resonance of the cable, θSD-NaIs the common mode short circuit impedance amplitude angle at the resonance of the cable, Real]Is a function of the real part, fNaIs the resonant frequency of the cable, j is the imaginary unit, Cp1And Cp2Are respectively a capacitor Cp1And Cp2Capacitance value, | ZOD-LFI is the low-frequency common-mode open-circuit impedance amplitude of the cable, | ZOD-HFI is the high-frequency common-mode open-circuit impedance amplitude of the cable, ROD-DCIs the common-mode open-circuit DC resistance of the cable, thetaOD-HFIs the high-frequency common-mode open-circuit impedance argument, | Z of the cableOD-NaI is the common-mode open-circuit impedance at resonance of the cable, Rp1And Rp2Are respectively a resistance Rp1And Rp2Is measured, | ZOD-Na|∠θOD-NaI.e. representing the complex plane at | ZOD-NaI is the modulus and the angle is thetaOD-NaComplex number of (a), thetaOD-NaIs the common mode open circuit impedance argument at resonance of the cable,// denotes the parallel operator.
CN202110690297.9A 2021-06-22 2021-06-22 Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system Pending CN113420398A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110690297.9A CN113420398A (en) 2021-06-22 2021-06-22 Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110690297.9A CN113420398A (en) 2021-06-22 2021-06-22 Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system

Publications (1)

Publication Number Publication Date
CN113420398A true CN113420398A (en) 2021-09-21

Family

ID=77789819

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110690297.9A Pending CN113420398A (en) 2021-06-22 2021-06-22 Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system

Country Status (1)

Country Link
CN (1) CN113420398A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115347762A (en) * 2022-10-18 2022-11-15 新创碳谷集团有限公司 Method and system for calculating cable length of frequency converter, and motor driving method and mechanism

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090228222A1 (en) * 2005-10-03 2009-09-10 Fantoni Paolo F Line Resonance Analysis System
US20110227669A1 (en) * 2010-03-18 2011-09-22 Nader Kalantari Method and apparatus for cable emulation
WO2014065674A1 (en) * 2012-10-24 2014-05-01 Wirescan As Method and system for monitoring a condition of electrical cables
US20180019699A1 (en) * 2016-07-15 2018-01-18 Onesubsea Ip Uk Limited Systems and methods for mitigating resonance in long cable drives
US20210083568A1 (en) * 2019-09-13 2021-03-18 Goodrich Control Systems Filter for power train
CN212909268U (en) * 2020-09-22 2021-04-06 杭州和昶电子科技有限公司 Frequency converter side motor filter applied to long-line driving occasion

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090228222A1 (en) * 2005-10-03 2009-09-10 Fantoni Paolo F Line Resonance Analysis System
US20110227669A1 (en) * 2010-03-18 2011-09-22 Nader Kalantari Method and apparatus for cable emulation
WO2014065674A1 (en) * 2012-10-24 2014-05-01 Wirescan As Method and system for monitoring a condition of electrical cables
US20180019699A1 (en) * 2016-07-15 2018-01-18 Onesubsea Ip Uk Limited Systems and methods for mitigating resonance in long cable drives
US20210083568A1 (en) * 2019-09-13 2021-03-18 Goodrich Control Systems Filter for power train
CN212909268U (en) * 2020-09-22 2021-04-06 杭州和昶电子科技有限公司 Frequency converter side motor filter applied to long-line driving occasion

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
WANG L 等: "High-Frequency Modeling and Filter Design for PWM Drives with Long Cables", 《ENERGIES》 *
王磊: "高功率因数变频器长线驱动系统的研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115347762A (en) * 2022-10-18 2022-11-15 新创碳谷集团有限公司 Method and system for calculating cable length of frequency converter, and motor driving method and mechanism
CN115347762B (en) * 2022-10-18 2022-12-13 新创碳谷集团有限公司 Frequency converter cable length calculation method and system, and motor driving method and mechanism

Similar Documents

Publication Publication Date Title
CN101710157B (en) EMI internal impedance measuring method based on double-resistance calibration and Marquardt method
CN112966408B (en) Method for predicting risk of electromagnetic interference of high-voltage conducted emission of all-in-one electric drive system
Meng et al. Noise source lumped circuit modeling and identification for power converters
WO2021253816A1 (en) Interference processing device, and electrical equipment and interference processing method therefor
US20110001495A1 (en) Test apparatus and method for measuring common-mode capacitance
Amara et al. Black box EMC modeling of a three phase inverter
CN104406509A (en) HHT (Hilbert Huang transform))-based electric cable length measuring method
CN105425038A (en) Measurement method for inter-harmonics of electric power system
CN113420398A (en) Comprehensive high-frequency modeling method for cable in variable-frequency motor long-line driving system
CN104714079A (en) Common-mode voltage measuring method for frequency converter
Li et al. Estimating the radiated emissions from cables attached to a switching power supply in a MIL-STD 461 test
Hillenbrand et al. Transient co-simulation of electromagnetic emissions caused by a SiC traction inverter
Wang et al. Modeling and evaluation of common-mode interference coupling effects on sensitive cable in motor drive system
Cuellar et al. Determination of the insertion loss of EMI filters using a black-box model
Nishiguchi et al. Conducted emissions simulation technology for an inverter device integrated into the motor
Li et al. Research on supraharmonic emission characteristics and influence factors of two-stage single-phase frequency converter
Duan et al. Differential mode conducted EMI prediction in three phase SiC inverters
Zhou et al. Prediction and reduction of electromagnetic conducted emission in active clamp forward converter
CN110632396B (en) Cable dielectric loss measuring method
Zhai et al. Design method of wide‐band high‐current air‐core inductor EMI filter for high voltage DC power of motor inverter of electric vehicle
Kovačević et al. Practical characterization of EMI filters replacing CISPR 17 approximate worst case measurements
Zhou Prediction and analysis of conduction electromagnetic interference in communication power
CN110927525A (en) Line fault identification PCA clustering method based on voltage change SOD curve cluster
Huang et al. EMI characterization with parasitic modeling for a permanent magnet motor drive
Choksi et al. Impact assessment of common-mode interference on communication cable in a motor drive system: Modified bulk current injection approach

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20210921

RJ01 Rejection of invention patent application after publication