CN104614595A - Non-contact Measurement Method of Natural Frequency and Quality Factor of Resonant Coil - Google Patents

Non-contact Measurement Method of Natural Frequency and Quality Factor of Resonant Coil Download PDF

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CN104614595A
CN104614595A CN201510076599.1A CN201510076599A CN104614595A CN 104614595 A CN104614595 A CN 104614595A CN 201510076599 A CN201510076599 A CN 201510076599A CN 104614595 A CN104614595 A CN 104614595A
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coil
impedance
natural frequency
real
quality factor
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朱春波
毛世通
魏国
逯仁贵
宋凯
李阳
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Harbin Institute of Technology Shenzhen
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Harbin Institute of Technology Shenzhen
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Abstract

A non-contact measurement method for natural frequency and quality factor of a resonance coil relates to a measurement technology for the natural frequency and the quality factor of the self-resonance coil by using self-distributed capacitance in a magnetic coupling resonance wireless power transmission system. The method aims to solve the problems that when the natural frequency and the quality factor of the resonant coil are measured by adopting a direct measurement method, errors are introduced, and the impedance is too large, so that the measurement result is inaccurate. The invention uses a primary magnetic field generated by a small standard coil to excite the coil to be measured so as to obtain impedance parameters. The impedance information of the coil to be measured can be obtained by calculating the impedance characteristic of the standard coil and comparing the impedance characteristic when the coil to be measured is not added, so that the natural frequency f of the self-resonance coil is measured and calculated0And a figure of merit method. The method has the characteristics of small introduced error, high measurement precision and convenience in measurement. The accuracy is improved by at least 20% compared to the direct measurement method.

Description

谐振线圈固有频率和品质因数的非接触式测量方法Non-contact Measurement Method of Natural Frequency and Quality Factor of Resonant Coil

技术领域technical field

本发明涉及磁耦合谐振无线电能传输系统中谐振线圈固有频率和品质因数的测量技术。The invention relates to the measurement technology of the natural frequency and quality factor of the resonant coil in the magnetic coupling resonant wireless power transmission system.

背景技术Background technique

应用于磁耦合谐振式无线电能传输系统的传输线圈承担着磁场与电场能量相互转化的任务,其自身谐振主要是靠线圈电感和谐振电容构成的谐振回路实现。谐振回路的固有频率决定系统的工作频率,而谐振回路的品质因数则是影响传输效率的重要参数。由于利用集中式电容存在焊点电阻以及自身内阻,容易降低线圈的品质因数,所以利用线圈自身的分布电容实现线圈的自谐振对无线电能传输效率的影响极大。但是在直接测量这种自谐振线圈的参数时会产生几个问题:1.线圈与探头接触处的分布参数对系统的测量结果会带来极大的影响;2.分布电容等效为集总参数时是与电感并联的结构,谐振处阻抗极大(无内阻时为无限大),反射损耗高,导致测量仪器无法准确测量,测量结果甚至不具有可信度。The transmission coil applied to the magnetically coupled resonant wireless power transmission system is responsible for the mutual conversion of magnetic field and electric field energy, and its own resonance is mainly realized by the resonant circuit composed of coil inductance and resonant capacitor. The natural frequency of the resonant circuit determines the operating frequency of the system, and the quality factor of the resonant circuit is an important parameter that affects the transmission efficiency. Since the use of concentrated capacitance has solder joint resistance and its own internal resistance, it is easy to reduce the quality factor of the coil, so the use of the distributed capacitance of the coil itself to realize the self-resonance of the coil has a great impact on the efficiency of wireless power transmission. However, there are several problems when directly measuring the parameters of this self-resonant coil: 1. The distribution parameters at the contact point between the coil and the probe will have a great impact on the measurement results of the system; 2. The distributed capacitance is equivalent to a lumped The parameter is a structure connected in parallel with the inductor, the impedance at the resonance is extremely large (infinitely large when there is no internal resistance), and the reflection loss is high, which makes the measuring instrument unable to measure accurately, and the measurement results are not even reliable.

发明内容Contents of the invention

本发明的目的是为了解决采用直接测量法测量谐振线圈固有频率和品质因数时,会引入误差,且阻抗过大,导致测量结果不准确的问题,提供一种谐振线圈固有频率和品质因数的非接触式测量方法。The purpose of the present invention is to solve the problem that when the natural frequency and quality factor of the resonant coil are measured by the direct measurement method, errors will be introduced, and the impedance is too large, resulting in inaccurate measurement results. contact measurement method.

本发明所述的谐振线圈固有频率和品质因数的非接触式测量方法包括以下步骤:The non-contact method for measuring the natural frequency and quality factor of the resonant coil of the present invention comprises the following steps:

步骤一、将阻抗测量装置测量标准线圈相连接;Step 1. Connect the impedance measuring device to measure the standard coil;

步骤二、利用阻抗测量装置测量标准线圈阻抗的实部Real(ZS(f))和虚部Imag(ZS(f))随频率变化的曲线,所述频率的范围为0~20M;Step 2, utilizing the impedance measuring device to measure the curves of the real part Real (Z S (f)) and the imaginary part Imag (Z S (f)) of the standard coil impedance as a function of frequency, and the range of the frequency is 0 ~ 20M;

步骤三、将标准线圈与待测线圈通过微弱磁场强度相互耦合;Step 3. Coupling the standard coil and the coil to be tested through a weak magnetic field strength;

步骤四、利用阻抗测量装置测量标准线圈阻抗的实部Real(Z0(f))和虚部Imag(Z0(f))随频率变化的曲线,f表示频率,所述频率的范围为0~20M;Step 4, utilize the impedance measuring device to measure the curves of the real part Real (Z 0 (f)) and the imaginary part Imag (Z 0 (f)) of the standard coil impedance as a function of frequency, f represents the frequency, and the range of the frequency is 0 ~20M;

步骤五、计算Real(ZC(f))与Imag(ZC(f));Step five, calculate Real(Z C (f)) and Imag(Z C (f));

Real(ZC(f))=Real(Z0(f))-Real(ZS(f)),Imag(ZC(f))=Imag(Z0(f))-Imag(ZS(f));Real(Z C (f))=Real(Z 0 (f))-Real(Z S (f)), Imag(Z C (f))=Imag(Z 0 (f))-Imag(Z S ( f));

步骤六、令Imag(ZC(f))=0,计算得到待测线圈的固有频率f0Step 6, make Imag(Z C (f))=0, calculate the natural frequency f 0 of the coil to be tested;

步骤七、构建新的阻抗复数ZC:ZC=Real(ZC(f))+i×Imag(ZC(f)),并计算ZC的模以及ZC的模的最大值,其中i代表虚数;Step 7. Construct a new impedance complex number Z C : Z C =Real(Z C (f))+i×Imag(Z C (f)), and calculate the modulus of Z C and the maximum value of the modulus of Z C , where i stands for imaginary number;

步骤八、计算ZC的模下降到所述最大值的(1/2)(1/2)倍时所对应的两个频率点f1和f2,并计算ZC的模的3db带宽Δf=f1-f2,最后计算待测线圈的品质因数Q:Step 8. Calculate the two frequency points f 1 and f 2 corresponding to when the mode of Z C drops to (1/2) (1/2) times of the maximum value, and calculate the 3db bandwidth Δf of the mode of Z C =f 1 -f 2 , finally calculate the quality factor Q of the coil to be tested:

QQ == ff 00 ΔfΔf ..

上述方法利用一个小型标准线圈产生的初级磁场激发待测线圈从而获取阻抗参数。通过计算标准线圈的阻抗特性并比对未加入待测线圈时的阻抗特性,可获取待测线圈的阻抗信息,从而测量线圈固有频率f0和品质因数的方法。这种方法具有引入误差小,测量精度高,测量方便的特点。与直接测量方法相比,准确度提高了至少20%。The above method uses a primary magnetic field generated by a small standard coil to excite the coil under test to obtain impedance parameters. By calculating the impedance characteristics of the standard coil and comparing the impedance characteristics when the coil under test is not added, the impedance information of the coil under test can be obtained, thereby measuring the natural frequency f 0 and quality factor of the coil. This method has the characteristics of small error, high measurement accuracy and convenient measurement. Accuracy is improved by at least 20% compared to direct measurement methods.

附图说明Description of drawings

图1为本发明所述的谐振线圈固有频率和品质因数的非接触式测量方法的原理示意图;Fig. 1 is the schematic diagram of the principle of the non-contact method for measuring the natural frequency and quality factor of the resonant coil according to the present invention;

图2为步骤二测量的阻抗的实部和虚部随频率变化的曲线,其中2表示虚部,3表示实部;Fig. 2 is the curve of the real part and the imaginary part of the impedance measured in step 2 as a function of frequency, wherein 2 represents the imaginary part and 3 represents the real part;

图3为步骤四测量的阻抗的实部和虚部随频率变化的曲线,其中4表示实部,5表示虚部;Fig. 3 is the curve of the real part and the imaginary part of the impedance measured in step 4 as a function of frequency, wherein 4 represents the real part and 5 represents the imaginary part;

图4为步骤七中阻抗复数ZC的实部和虚部随频率变化的曲线;其中6表示实部,7表示虚部;Fig. 4 is the curve that the real part and the imaginary part of impedance complex number Z C vary with frequency in step 7; wherein 6 represents the real part, and 7 represents the imaginary part;

图5为步骤七中阻抗复数ZC的模随频率变化的曲线;Fig. 5 is the curve that the modulus of impedance complex number Z C changes with frequency in step 7;

图2至图5中,横坐标表示角频率,纵坐标表示阻抗的实部和虚部的值。In FIGS. 2 to 5 , the abscissa represents the angular frequency, and the ordinate represents the values of the real and imaginary parts of the impedance.

具体实施方式Detailed ways

具体实施方式一:结合图1说明本实施方式,本实施方式所述的谐振线圈固有频率和品质因数的非接触式测量方法包括以下步骤:Specific Embodiment 1: This embodiment is described in conjunction with FIG. 1. The non-contact method for measuring the natural frequency and quality factor of the resonant coil described in this embodiment includes the following steps:

步骤一、将阻抗测量装置测量标准线圈1相连接;Step 1, connect the standard coil 1 of the impedance measuring device;

步骤二、利用阻抗测量装置测量标准线圈1阻抗的实部Real(ZS(f))和虚部Imag(ZS(f))随频率变化的曲线,所述频率的范围为0~20M;Z表示阻抗;Step 2, using the impedance measuring device to measure the curves of the real part Real (Z S (f)) and the imaginary part Imag (Z S (f)) of the impedance of the standard coil 1 as a function of frequency, and the range of the frequency is 0 ~ 20M; Z means impedance;

步骤三、将标准线圈1与待测线圈通过微弱磁场强度相互耦合;Step 3. Coupling the standard coil 1 and the coil to be tested through a weak magnetic field strength;

步骤四、利用阻抗测量装置测量标准线圈1阻抗的实部Real(Z0(f))和虚部Imag(Z0(f))随频率变化的曲线,f表示频率,所述频率的范围为0~20M;Step 4, utilize the impedance measuring device to measure the curve of the real part Real (Z 0 (f)) and the imaginary part Imag (Z 0 (f)) of the impedance of the standard coil 1 as a function of frequency, f represents the frequency, and the range of the frequency is 0~20M;

步骤五、计算Real(ZC(f))与Imag(ZC(f));Step five, calculate Real(Z C (f)) and Imag(Z C (f));

Real(ZC(f))=Real(Z0(f))-Real(ZS(f)),Imag(ZC(f))=Imag(Z0(f))-Imag(ZS(f));Real(Z C (f))=Real(Z 0 (f))-Real(Z S (f)), Imag(Z C (f))=Imag(Z 0 (f))-Imag(Z S ( f));

步骤六、令Imag(ZC(f))=0,计算得到待测线圈的固有频率f0;这里的计算过程实际上是寻找令Imag(ZC(f))=0或最接近0的频率点,此频率点为f0Step 6: Let Imag(Z C (f))=0, and calculate the natural frequency f 0 of the coil to be tested; the calculation process here is actually to find the Imag(Z C (f))=0 or the closest to 0 Frequency point, this frequency point is f 0 ;

步骤七、构建新的阻抗复数ZC:ZC=Real(ZC(f))+i×Imag(ZC(f)),并计算ZC的模以及ZC的模的最大值,其中i代表虚数;Step 7. Construct a new impedance complex number Z C : Z C =Real(Z C (f))+i×Imag(Z C (f)), and calculate the modulus of Z C and the maximum value of the modulus of Z C , where i stands for imaginary number;

步骤八、计算ZC的模下降到所述最大值的(1/2)(1/2)倍时所对应的两个频率点f1和f2,并计算ZC的模的3db带宽Δf=f1-f2,最后计算待测线圈的品质因数Q:Step 8. Calculate the two frequency points f 1 and f 2 corresponding to when the mode of Z C drops to (1/2) (1/2) times of the maximum value, and calculate the 3db bandwidth Δf of the mode of Z C =f 1 -f 2 , finally calculate the quality factor Q of the coil to be tested:

QQ == ff 00 ΔfΔf ..

本实施方式采用一种标准线圈1与待测线圈通过微弱磁场强度的耦合获取待测线圈的特征参数,即固有频率f0和品质因数Q。所述的标准线圈1为小型单匝线圈,其固有频率大于100MHz。所述待测线圈为用于磁耦合谐振式无线电能传输的自谐振线圈,其线圈自感为自身分布电感,其谐振电容为自身分布式电容。自谐振线圈的固有频率为自身多个固有频率点中的最低频率点。待测线圈与标准线圈1之间存在磁场耦合,其耦合系数不小于0.05。所述标准线圈1与阻抗测量装置相连接。由于标准线圈1与待测线圈之间不存在电气接触,能够避免直接测量法所产生的问题,测量结果的准确度提高了20%。图2至图5所示为测量及计算结果。In this embodiment, a standard coil 1 is coupled with the coil to be tested to obtain the characteristic parameters of the coil to be tested, ie, the natural frequency f 0 and the quality factor Q, through the coupling of a weak magnetic field. The standard coil 1 is a small single-turn coil whose natural frequency is greater than 100 MHz. The coil to be tested is a self-resonant coil for magnetically coupled resonant wireless power transmission, its coil self-inductance is its own distributed inductance, and its resonant capacitance is its own distributed capacitance. The natural frequency of the self-resonant coil is the lowest frequency point among the multiple natural frequency points of the self-resonant coil. There is magnetic field coupling between the coil to be tested and the standard coil 1, and its coupling coefficient is not less than 0.05. The standard coil 1 is connected with an impedance measuring device. Since there is no electrical contact between the standard coil 1 and the coil to be tested, the problems caused by the direct measurement method can be avoided, and the accuracy of the measurement result is increased by 20%. Figures 2 to 5 show the measurement and calculation results.

具体实施方式二:本实施方式是对实施方式一所述的谐振线圈固有频率和品质因数的非接触式测量方法的进一步限定,本实施方式中,所述阻抗测量装置为阻抗分析仪或网络分析仪。Specific Embodiment 2: This embodiment is a further limitation of the non-contact measurement method for the natural frequency and quality factor of the resonant coil described in Embodiment 1. In this embodiment, the impedance measurement device is an impedance analyzer or a network analyzer instrument.

具体实施方式三:本实施方式是对实施方式一所述的谐振线圈固有频率和品质因数的非接触式测量方法的进一步限定,本实施方式中,所述阻抗测量装置与标准线圈1的连接采用同轴电缆或双绞线。Specific Embodiment 3: This embodiment is a further limitation of the non-contact measurement method for the natural frequency and quality factor of the resonant coil described in Embodiment 1. In this embodiment, the connection between the impedance measuring device and the standard coil 1 adopts coaxial cable or twisted pair.

具体实施方式四:本实施方式是对实施方式一所述的谐振线圈固有频率和品质因数的非接触式测量方法的进一步限定,本实施方式中,步骤三中标准线圈1与待测线圈之间的耦合系数为0.01~0.5。Specific Embodiment 4: This embodiment is a further limitation of the non-contact measurement method for the natural frequency and quality factor of the resonant coil described in Embodiment 1. In this embodiment, the standard coil 1 in step 3 and the coil to be tested The coupling coefficient is 0.01~0.5.

Claims (4)

1.谐振线圈固有频率和品质因数的非接触式测量方法,其特征在于:该方法包括以下步骤:1. The non-contact measuring method of natural frequency and quality factor of resonant coil, it is characterized in that: the method comprises the following steps: 步骤一、将阻抗测量装置测量标准线圈(1)相连接;Step 1, connecting the measuring standard coil (1) of the impedance measuring device; 步骤二、利用阻抗测量装置测量标准线圈(1)阻抗的实部Real(ZS(f))和虚部Imag(ZS(f))随频率变化的曲线,所述频率的范围为0~20M;Step 2, utilize the impedance measuring device to measure the curve of the real part Real (Z S (f)) and the imaginary part Imag (Z S (f)) of the standard coil (1) impedance as a function of frequency, and the range of the frequency is 0~ 20M; 步骤三、将标准线圈(1)与待测线圈通过微弱磁场强度相互耦合;Step 3, coupling the standard coil (1) and the coil to be tested with each other through a weak magnetic field strength; 步骤四、利用阻抗测量装置测量标准线圈(1)阻抗的实部Real(Z0(f))和虚部Imag(Z0(f))随频率变化的曲线,f表示频率,所述频率的范围为0~20M;Step 4, utilize impedance measuring device to measure the curve of real part Real (Z 0 (f)) and imaginary part Imag (Z 0 (f)) of standard coil (1) impedance as a function of frequency, f represents frequency, and the curve of described frequency The range is 0~20M; 步骤五、计算Real(ZC(f))与Imag(ZC(f));Step five, calculate Real(Z C (f)) and Imag(Z C (f)); Real(ZC(f))=Real(Z0(f))-Real(ZS(f)),Imag(ZC(f))=Imag(Z0(f))-Imag(ZS(f));Real(Z C (f))=Real(Z 0 (f))-Real(Z S (f)), Imag(Z C (f))=Imag(Z 0 (f))-Imag(Z S ( f)); 步骤六、令Imag(ZC(f))=0,计算得到待测线圈的固有频率f0Step 6, make Imag(Z C (f))=0, calculate the natural frequency f 0 of the coil to be tested; 步骤七、构建新的阻抗复数ZC:ZC=Real(ZC(f))+i×Imag(ZC(f)),并计算ZC的模以及ZC的模的最大值,其中i代表虚数;Step 7. Construct a new impedance complex number Z C : Z C =Real(Z C (f))+i×Imag(Z C (f)), and calculate the modulus of Z C and the maximum value of the modulus of Z C , where i stands for imaginary number; 步骤八、计算ZC的模下降到所述最大值的(1/2)(1/2)倍时所对应的两个频率点f1和f2,并计算ZC的模的3db带宽Δf=f1-f2,最后计算待测线圈的品质因数Q:Step 8. Calculate the two frequency points f 1 and f 2 corresponding to when the mode of Z C drops to (1/2) (1/2) times of the maximum value, and calculate the 3db bandwidth Δf of the mode of Z C =f 1 -f 2 , finally calculate the quality factor Q of the coil to be tested: QQ == ff 00 ΔfΔf .. 2.根据权利要求1所述的谐振线圈固有频率和品质因数的非接触式测量方法,其特征在于:所述阻抗测量装置为阻抗分析仪或网络分析仪。2. The non-contact method for measuring the natural frequency and quality factor of the resonant coil according to claim 1, wherein the impedance measuring device is an impedance analyzer or a network analyzer. 3.根据权利要求1所述的谐振线圈固有频率和品质因数的非接触式测量方法,其特征在于:所述阻抗测量装置与标准线圈(1)的连接采用同轴电缆或双绞线。3. The non-contact method for measuring the natural frequency and quality factor of the resonant coil according to claim 1, characterized in that: the connection between the impedance measuring device and the standard coil (1) adopts a coaxial cable or a twisted pair. 4.根据权利要求1所述的谐振线圈固有频率和品质因数的非接触式测量方法,其特征在于:步骤三中,标准线圈(1)与待测线圈之间的耦合系数为0.01~0.5。4. The non-contact method for measuring the natural frequency and quality factor of the resonant coil according to claim 1, characterized in that: in step 3, the coupling coefficient between the standard coil (1) and the coil to be tested is 0.01-0.5.
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CN106645971A (en) * 2017-01-24 2017-05-10 佛山市瑞福物联科技有限公司 Method for testing belt packaging impedance of ultrahigh frequency RFID chip through resonance method
CN108008222A (en) * 2017-12-05 2018-05-08 华南理工大学 A kind of coupled resonators parameter extraction device and its extracting method
CN108872753A (en) * 2018-07-17 2018-11-23 中国电力科学研究院有限公司 The method and apparatus for testing transmission coil quality factor in high frequency wireless power transmission systems
CN111190058A (en) * 2020-02-12 2020-05-22 南京理工大学 Micro-resonator natural frequency and quality factor synchronous measurement system

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