KR20050078950A - A true impedance value measuring method, immunized from mixed noise - Google Patents

Abstract

 Battery systems are widely used in emergency power facilities or communication network power installations, and efficient management of them has become an important issue. If a failure occurs even in one cell of batteries connected in series while the battery system is operating, the reliability of the emergency power system cannot be secured, which causes problems in stable operation of critical equipment such as communication networks.

  The measurement diagnostic method that selects only bad batteries while operating them in the floating charging state at all times without disconnecting them from the operating system. Will be calculated (measured) in real time. However, the measured battery terminal voltage is measured not only with the voltage drop due to the constant current supplied for the internal impedance measurement, but also with the harmonic ripple voltage due to the battery charging current flowing from the power source during floating charging. Becomes difficult. The present invention proposes a method for enabling accurate calculation of internal impedance by separating only a voltage drop component due to internal impedance from the harmonic ripple voltage and other noise for accurate internal impedance calculation (measurement).

In addition, even when the electrolytic capacitor in the power converter is deteriorated due to evaporation of the electrolyte, it is possible to estimate the capacitor capacity and diagnose the deterioration state by applying the same principle and calculation method proposed in the present invention.

Description

Robust impedance measurement method for mixed noise signals {A true impedance value measuring method, immunized from mixed noise}

To determine the degree of deterioration of a workpiece with increasing internal impedance with aging, such as a battery, AC constant current (I _S ) flows across the terminals of the workpiece, such as a battery, and its voltage drop component (V _IS) In general, a method of diagnosing a sound state by measuring (operating) an internal impedance by measuring a) is common.

A commonly used internal impedance calculation measures the effective value of the voltage drop component (V _IS ) and the AC constant current (I _S ) and the phase difference θ therebetween, and calculates the internal impedance. Is calculated by. At this time, V _{IS and RMS} are the effective values of the impedance voltage V _IS and I _{S and RMS} are the effective values of the AC constant current I _S.

In general, since the internal impedance of a large capacity battery has a very small value of several milliohms (mΩ), the voltage due to the internal impedance of a battery cell is several mV or less and is generally very small. In the case of using the method, a circuit having a function as shown in FIG. 1 is generally used for accurate measurement of V _{IS, RMS} and I _{S, RMS} . That is, AC constant current (I _S ) flows between both terminals of the measurement object such as battery through the source terminal of the constant current source circuit located in the circuit to minimize the effects such as the lead resistance of the lead or the contact resistance of the plug. Use to reduce the influence of lead wire resistance and contact resistance, and measure the voltage drop component (V _IS ) (hereinafter referred to as impedance voltage) due to internal impedance from both terminals of the battery through the sense terminal of the 4-terminal network. After that, the impedance voltage V _IS measured at the battery terminal is converted into a pure AC signal through an amplifier coupled with a capacitor and amplified by the amplifier. The AC constant current I _S is converted into a voltage signal through a shunt and amplified by an amplifier. The amplified impedance voltage V _IS and the AC constant current I _S signal are converted into digital signals through an A / D converter and used for internal impedance calculation by a processor such as a microcontroller (MCU).

On the other hand, synchronous detection is widely used as another method to calculate the impedance of the measured object by flowing arbitrary constant current (I _S ) to the measured object and measuring the voltage drop caused by the internal impedance. . As shown in FIG. 2, an arbitrary impedance voltage (V _IS ) signal measured from an object under test is measured. Denotes a constant current (I _S ) signal Represented by Where n is an integer greater than or equal to 1 and ω is an arbitrary frequency. In addition, the impedance voltage (V _IS ) signal and the constant current (I _S ) signal have a phase difference between each other by θ angle and are pure sinusoidal waveforms having no harmonic components of 2A and 2B, respectively.

, Assume that m ₁ , m ₂ , m ₃ and m ₄ can be calculated as follows.

(One)

(2)

(3)

(4)

In each term of said Formula (1), Formula (2), Formula (3), and Formula (4) By removing them by any means capable of removing only the alternating components having a frequency, equations (1), (2), (3) and (4) are the following M ₁ , M ₂ , M ₃ and M _{As in 4} , only the DC component remains.

(5)

(6)

(7)

(8)

As mentioned above, the impedance Since it can be represented by, it can be expressed as follows using equations (5), (6), (7) and (8). In other words,

(9)

As can be seen in Equation (9), the impedance of the object to be measured can be easily calculated using the calculation process of Equations (5), (6), (7) and (8). .

In addition, as described above, an integrated circuit (IC) capable of multiplying and measuring internal impedance has been commercialized from the impedance AC voltage V _IS and the constant current I _S signal according to the principle of the synchronous detection method.

As described above, the respective effective values of the impedance voltage (V _IS ) and the AC constant current (I _S ) signal and the phase difference θ between these signals are measured for the purpose of calculating the impedance effective value, and the internal impedance is measured. In the case of using the calculation method according to the present invention, the impedance voltage (V _IS ) signal measured and induced by the AC constant current (I _S ) at a terminal of a workpiece such as a battery is measured as the charging voltage (V _DC ) of the battery as described above. Compared to a small signal (a few thousandths), a small signal of a few mV units and affected by the electromagnetic noise of the surroundings, it is optimal to design a noise canceling circuit such as a bandpass filter so that the AC constant current (I _S) It is necessary to extract only the impedance voltage (V _IS ) indicated by) and to amplify it. In addition, when the battery is operating in the floating charge state, it is very difficult to accurately extract only the impedance voltage V _IS from the terminal voltage of the battery by introducing a harmonic charging ripple current from the power supply side. The harmonic ripple voltage generated by the harmonic charging ripple current is different depending on the rectification method of the charging device, but includes several orders of harmonic ripple components, and most of the high frequency ripple voltages are removed by a noise removing circuit such as the band pass filter. Can be. However, the high frequency ripple voltage in the frequency region adjacent to the frequency of the AC constant current I _S is not completely removed by the noise canceling circuit. As an example, when the frequency of the AC constant current (I _S ) is about 1 KHz, the harmonic ripple voltage of 900-1140 Hz, which is similar to the internal impedance voltage (V _IS ) used for the measurement, is not sufficiently filtered (attenuated). The internal impedance effective value of H is severely affected when measuring or calculating. Therefore, in order to calculate (measure) the internal impedance (effective component) value based on the impedance voltage V _IS and the AC constant current I _{S as} described above, the harmonic ripple voltage caused by the charging current on the power supply side due to the floating charging of the capacitor. Noise voltage components due to parasitic impedance, such as the wiring voltage drop of the measurement circuit and the measurement voltage are measured together with the impedance voltage V _IS , which causes a lot of errors in the calculation of the internal impedance.

In addition, even when the effective value of the impedance voltage (V _IS ) and the AC constant current (I _S ) can be calculated by any method and the phase angle θ can be measured with an accurate value within 0.5%, If the phase angle θ is more than 85 °, the value of cos (θ) becomes close to 0 (zero), resulting in a very large internal impedance error. In this case, the error due to the computational resolution by the processor cannot be ignored. For example, when the phase angle θ values are 85 ° and 85.42 °, cos (85 °) and cos (85.42 °) are about. There is a 10% difference, which directly affects the internal impedance calculation result, resulting in a problem that the impedance measurement error is about 10% or more.

According to the method of synchronous detection, which is another measuring method, an error caused by cos (θ) becomes close to 0 (zero) when the phase angle θ is 85 ° or more can be solved to some extent. . However, due to the floating charge of the battery in the impedance AC voltage (V _IS ) signal Harmonic ripple voltage generated by harmonic charging ripple current, When the harmonic noise introduced to the outside is included, the implementation is very difficult and the accuracy of the measurement is greatly reduced due to the noise.

In more detail, when the multiple-order harmonic ripple voltage or harmonic noise is measured by simultaneously mixing the impedance AC voltage (V _IS ) signal by the AC constant current (I _S ), equations (1), (2), In order to selectively extract only the direct current components (5), (6), (7), and (8) of each term from (3) and (4), a filter having a very low cutoff frequency is essential. Although necessary, the implementation of an ideal filtering circuit having no attenuation characteristics for the DC component is practically impossible, and thus causes a large error in the measured value during impedance calculation by a known synchronous detection method.

In addition, even if filtering (attenuation) is performed by removing a noise removing circuit having a function as applied in FIG. 1 to remove harmonic components from the measured impedance AC voltage V _IS , the frequency of the AC constant current I _S is increased. The high frequency ripple voltage in the frequency domain is not completely eliminated by the noise canceling circuit, and at the final measurement signal (V _{IS '} ), the high frequency ripple voltage and the AC constant current (I _S ) of the multiple-order harmonic ripple voltage of the commercial power supply (60 or 50 hz). When the impedance AC voltage (V _IS ) is measured and mixed at the same time, and the frequency of the AC constant current (I _S ) is about 1KHz, as in the embodiment, the 15th order of the commercial power supply 60Hz is 900Hz, the 16th order is 960Hz, the 17th order is 1020Hz, Since 18th order 1080Hz and 19th order 1140Hz (16th order 960Hz and 18th order 1080Hz in the case of single-phase rectifier) are included without attenuation, the DC components of the terms (5), (6), (7) and ( 8) only optional In order to extract the filter would be necessary to remove the AC component of 200Hz or more. The measuring device is designed using an integrated circuit (IC) that can multiply and measure the internal impedance by synchronous detection. When measuring a battery connected in a floating state, the impedance AC voltage as mentioned above Since the effect of harmonic ripple voltage near the frequency band (V _IS ) cannot be completely excluded, the measurement error is very large due to the inflow of harmonic ripple voltage caused by the charging current of the power supply side due to the floating charge of the battery.

In addition, to calculate m ₁ , m ₂ , m ₃ and m ₄ , as in equations (1), (2), (3) and (4): , Requires a coding value of. The coded values impedance AC voltage (V _IS) and AC constant current (I _S) it must have a frequency exactly matches the sync frequency and the impedance of the alternating voltage (V _IS) and AC constant current (I _S) from the PLL (Phase To this It may be provided with any device for obtaining a frequency, such as (Lock Loop). However, this is accompanied by a certain frequency error, especially when including the harmonic components as described above has a problem that it is very difficult to ensure sufficient accuracy.

The present invention is to solve the above problems as described above, when the battery is floating charge, the harmonic ripple voltage caused by the power supply side charging current is excluded and the resolution problem due to the phase angle θ is completely improved to improve the accuracy of the measurement. Increase the synchronous signal , To make it easy to secure the coding value of, and to propose the algorithm and the method to calculate the impedance effective value accurately by measuring only the impedance AC voltage (V _IS ) by the constant current (I _S ) signal in the noise noise signal. do.

According to the present invention, when calculating an internal impedance effective value of a measurement object such as a battery, an impedance factor (V _IS ) caused by AC constant current (I _S ) and a charge current of the battery are applied to external factors such as high frequency ripple voltage (V _RP ). The present invention provides a method for acquiring a measurement voltage signal (V _SM ) containing a large amount (mixed) of noise induced in a measurement object and accurately acquiring an internal impedance of the measurement object using the AC constant current (I _S ). It will be described in detail by the storage battery in the floating charge as an embodiment.

The fundamental frequency (60 or 50 Hz) of the commercial power supply used for floating charging the battery is called ω, and the frequency of the constant current (I _S ) supplied to the battery cell for which the internal impedance is to be measured is the frequency of the fundamental wave frequency ω of the power supply. n + 0.5) times to determine the frequency of (n + 0.5) ω. N is an integer of 1 or more. At this time, since the impedance voltage V _IS of the battery is generated by the constant current I _S , the frequency thereof is also a (n + 0.5) difference frequency, which can be represented by Equations (10) and (11), respectively.

10

(11)

_Is the phase difference between the impedance voltage V _IS and the constant current I _S.

The high-frequency ripple voltage (V _RP ) varies depending on the charger's rectification method (constant) due to the charging current due to the battery's floating charging. However, in the case of the single-phase rectification method, the basic frequency (60 or 50 Hz) of the commercial power supply is excellent. In the case of three-phase rectification, it has an odd (odd) times ripple frequency component, so the general high frequency ripple voltage (V _RP ) can be expressed as an integer multiple of the fundamental frequency ω as shown in Equation (12). .

(12)

Where s is And m is Is an integer and 2K _i represents the maximum value of the i- th harmonic ripple.

As described above, a noise canceling circuit such as a bandpass filter or a narrowband filter is designed so that only a signal corresponding to the (n + 0.5) order harmonic frequency is passed, thereby reducing the high frequency ripple voltage (V _RP ). Remove and let only equation (10) impedance voltage (V _IS ) be selected. The ideal noise canceling circuit passes only signals corresponding to the (n + 0.5) order frequency that is correctly set as the pass frequency, but it is impossible to implement them in reality, and its performance is partially changed according to changes in the surrounding environment such as temperature and humidity. Conventional noise reduction circuits are known to attenuate only about 30% of the frequency components adjacent to the low cutoff frequency f _L or the high cutoff frequency f _H. When designing a narrowband filter, the resonant frequency (fr) is equal to the (n + 0.5) order harmonic, the low cutoff frequency is approximately equal to the (n-2) difference, and the high pass cutoff frequency is (n + 2) difference. It is designed to be almost equal to harmonics so that it is designed to be almost filtered (attenuated) in the other frequency ranges so that only the impedance voltage V _IS is selectively passed through as much as possible. Since the harmonic ripple voltage after passing through the noise canceling circuit exists only in components of a frequency band similar to the frequency of the constant current I _S , the high frequency ripple voltage V _RP shown in Equation (12) is constant s and m is n. In this case, the harmonic ripple voltage after passing the noise elimination circuit is also expressed by Equation (12) for convenience.

The AC instantaneous voltage signal V _SM measured by the terminal voltage of the battery is measured together with the high frequency ripple voltage V _RP after passing through the impedance voltage signal V _IS and the noise removing circuit. It can be expressed as the sum of 12).

(13)

Cosine wave C represented by Eqs. (14) and (15) having a synchronizing frequency exactly matched to the frequencies of the impedance alternating current V _IS and the alternating current I _S by any circuit or means. _{If 1} and sine wave S ₁ are obtained,

(14)

(15)

Similar to the synchronous detection method described above, the AC instantaneous voltage V _SM of Equation (13) and the constant current I _S of Equation (11) measured at the terminal voltage of the battery are correlated with Eqs. (14) and (15). Multiply m ₁ , m ₂ , m ₃ and m ₄ as follows. In other words,

(16)

(17)

(18)

(19)

Each term in equations (16), (17), (18) and (19) consists of a DC component that does not change with time t and a sinusoidal AC component that changes periodically (ωt) with time t. have.

As mentioned above, since a filter having a very low cutoff frequency inevitably filters (attenuates) not only an AC component but also a DC component, it has already been described that it is impossible to apply the filter. In the present invention, to compensate for this disadvantage, the following method is applied. As in Eq. (20), each frequency of an arbitrary sinusoid If and as a multiple of the fundamental frequency ω _S, performed in the integration during a period corresponding to the fundamental frequency ω _S the integrated value to zero (0) and equal to the fact that previously known, and that is,

here, Is an integer (20)

Since the AC components of the formulas (16), (17), (18) and (19) all have angular frequencies expressed by integer multiples of 0.5 × ω, the above formulas (16), (17), Integrating (18) and (19) into the integral period (T _D ) of Eq. (21) and integrating them, respectively, and taking the average value, the result is that each term of all AC components except DC is zero. Will be.

(21)

When the direct current components obtained above are represented by M ₁ , M ₂ , M _3, and M _{4, they} are represented by the formulas (22), (23), (24) and (25), that is,

(22)

(23)

(24)

(25)

Equations (22), (23), (24) and (25) are the same as the results of the above-described formulas (5), (6), (7) and (8). In the same way as

(26)

Therefore, even when the impedance voltage signal V _IS and the high frequency ripple voltage V _RP are mixed, the equation (16), (17), during the half period (30 or 25 Hz) of the fundamental frequency (60 or 50 Hz) ω of the commercial power supply. By integrating Equation (18) to obtain the average value, the impedance effective value can be calculated exactly by the calculation process by the synchronous detection method.

As described above, the harmonic charging ripple voltage (V _RP ) that is generally generated during floating charging is usually a multiple of one of odd (odd) times and even (excellent) times of the fundamental frequency (60 or 50 Hz) ω of the commercial power supply. It only has a corresponding ripple frequency component. When only a certain multiple ripple component of odd (odd) and even (excellent) times exists as described above, the frequency of the constant current (I _S ) supplied to the battery cell to measure the internal impedance as shown in Equation (27) is determined by the power supply. Determine the nth frequency, which is n times the fundamental wave frequency of ω (60 / 50hz) (where n is an integer greater than 1), but if there are only even-number ripple frequency components, n is odd and odd ( If only the ripple frequency component is present, n is set to an even number so that a constant current (I _S ) having a frequency of the corresponding n-th order is flowed into the battery. The impedance voltage V _IS by the constant current I _S is represented by Equation (28).

(27)

(28)

The AC instantaneous voltage signal (V _SM ) measured by the terminal voltage of the battery is

(29)

It can be represented as. Here, x is 1 when only odd (odd) times are present and even (excellent) times is 0.

As described above, m ₁ , m ₂ , m _3, and m ₄ are obtained by using the AC instantaneous voltage signal (V _SM ) of Equation (29) and the constant current (I _S ) of Equation (27) measured as the terminal voltage. From this, it is obvious that the impedance effective value can be calculated by obtaining M ₁ , M ₂ , M _3, and M ₄ obtained by extracting only the DC component and substituting it into Equation (26). However, in order to calculate M ₁ , M ₂ , M _3, and M ₄ , integrating and taking the average value, the components of m ₁ , m ₂ , m _3, and m ₄ are all expressed as integer multiples of ω. Use the integral period T _D as shown in 30).

(30)

Compared to Equation (21), the integration period is reduced by half, enabling faster impedance calculations when calculating impedance values, and when using a digital computing device such as a microprocessor, the memory capacity required for the calculation is cut in half. It will have the advantage that it can.

Looking at the calculation process of the above two embodiments in detail, the integral period (T _D ) used to extract only the DC component of m ₁ , m ₂ , m ₃ and m ₄ by synchronous detection method is the AC instantaneous voltage (V _SM) The frequencies of all harmonic components constituting) are mutually added and subtracted, and the greatest common divisor between the result of addition and subtraction can be found and determined as an integer multiple of them. In order to reduce the time required to calculate the effective impedance value and to pursue economic feasibility, the maximum common factor between the calculated values must be minimized. Therefore, the frequency of the constant current I _S supplied to the battery cell is changed to the high frequency ripple voltage V _RP . Select harmonic voltages different from the frequency of all harmonic voltages, and arrange each harmonic constituting the high frequency ripple voltage (V _RP ) in the order of magnitude, and randomly select the frequency ω _IS of the constant current (I _S ) within the selected range. The integral period (T _D ) can be reduced to a minimum by selecting the frequency equal to the average value of two adjacent harmonics.

For example, if the order of harmonics constituting the high frequency ripple voltage (V _RP ) is composed of harmonics of all integer orders, such as the first order, second order third order ... of the fundamental wave frequency ω (60 / 50hz) ... The frequency of the constant current I _S supplied to the cell is determined to be the (n + 0.5) difference frequency, which is (n + 0.5) times the fundamental wave frequency ω (60/50 hz) of the power supply, and thus the constant current I _S as described above. The difference between the frequencies of) and the frequencies of all harmonic components of the high frequency ripple voltage (V _RP ), respectively, is equal to 0.5 × ω.

In addition, when the harmonic order constituting the high frequency ripple voltage (V _RP ) is composed of only odd (odd) or even (excellent) difference, the frequency of the constant current (I _S ) supplied to the battery cell is supplied to the commercial power supply frequency ω, respectively. Select an odd (odd) or even (odd) difference frequency of (60 / 50hz) so that the values of all the harmonic components difference (-) are equal to ω.

The conceptual concept of calculating the internal impedance of the object to be measured from the series of AC instantaneous voltage V _SM and the constant current I _S is software programmed by driving a digital numerical operation device (hereinafter referred to as MPU) such as a microprocessor. 3 is a conceptual flow diagram of a software algorithm implemented through an application program, and FIG. 4 is a conceptual block diagram of the entire system.

In more detail, the constant current source initializes all internal variables such as a counter of the MPU 101 through the initialization process of the MPU 101, and generates a constant current I _S by a series of commands of the MPU 101. The 102 is operated, the constant current I _S flows into the measurement object 103, and the constant current I _S signal and the AC instantaneous voltage V _SM are input to the A / D converter 104. In the next step, the sign values and the cosine values obtained by a series of means tabled (coded) and stored in the memory device 105 or calculated in real time are read and converted into digital values through the A / D converter 104. The input constant current I _S signal and the AC instantaneous voltage V _SM value are read for each sampling time point ni, ..., n, n + 1 shown in FIG. 5 for a predetermined integration period T _D. This time point may be determined by a timer 106 installed inside or outside the MPU 10. Next, m1, m2, m3, and m4 values are calculated using equations (16), (17), (18) and (19), and the corresponding values are accumulated at the previous sampling time point and accumulated. If the sampling time is increased and the time corresponding to the predetermined integration period T _D (or sampling N times) is reached, the process is repeated. If it reaches, the constant current source 102, which stops performing repetition and makes a constant current I _S , stops operating, and the average value M1 during the period T _D of the m1, m2, m3, m4 values accumulated so far , M2, M3, M4 is calculated, and the internal impedance value can be calculated by the above equation (26).

In the above process, the MPU 10 has a waveform that is exactly synchronized with the frequency of the impedance AC voltage V _IS and the AC constant current I _S , that is, , Is needed at that sampling point. To this end, any device for acquiring a synchronized frequency, such as a phase lock loop (PLL), may be provided from the impedance AC voltage V _IS and the AC constant current I _S. However, this is accompanied by a certain frequency error, especially when it contains a harmonic component is a problem that it is very difficult to ensure sufficient accuracy. Therefore, the present invention proposes the following method in order to minimize the calculation error and easily implement.

This will be described in detail through a conceptual block diagram of the entire system of the apparatus of FIG. 4. The basic clock generated from the clock generator 107 is input to the MPU 101 to be an operation clock required for operation, and the basic clock. by using a frequency divider 108 to frequency divider input to the CLOCK frequency divider as a constant current source 102 to be based on creating an AC constant current (I _S). It is also possible to make a divided CLOCK using a counter in the MPU 101 without having to divide a divider 108 for dispensing the basic clock. The frequency of the AC constant current I _S is determined by the method proposed in the present invention, which is known or inputs the current command value from the constant current source 102 from the MPU 101. Since the frequency of the impedance AC voltage (V _IS ) is the same as the AC constant current (I _S ), this is already a known value and can be calculated without a separate device such as a PLL by the above configuration. In addition, since the operation clock of the MPU 101 and the clock of the constant current source 102 used to make the constant current Is are generated from the same clock generator 107 in the above configuration, a slight error according to the individual characteristics of the clock generator. I can also reduce , It is possible to easily secure its accuracy when obtaining.

The internal impedance is calculated by equation (26) using the synchronous detection method as described in the present invention. Where M ₁ , M ₂ , M _3, and M ₄ , such as equations (22), (23), (24) and (25), , , . It can be seen that it is represented by. If phase angle or If the angle is close to 90 degrees and their cosine calculations are close to zero, errors due to computational resolution by the processor may occur, which may involve a large error (%) during impedance calculation. , Make sure that the angle is not as close to 90 degrees and that these two values are as close to 45 degrees or 135 degrees as possible. Select a value. For example, when the measured object is a storage battery, when the capacity of the storage battery (AH) is large or the frequency of the constant current (I _S ) is high, the phase difference between the constant current (Is) and the impedance voltage signal approaches 90 degrees. If the value is set to about 45 degrees or 135 degrees, accurate calculation result can be obtained.

As described above, the present invention effectively reduces the calculation error caused by the noise signal even when the impedance voltage V _IS is obtained by mixing with the noise signal such as the ripple voltage V _RP . Make sure you get it right. In addition, the resolution problem due to the phase angle θ in the conventional measurement method is completely improved to increase the accuracy of the measurement. A method for minimizing the error when acquiring the synchronous frequency is proposed and the algorithm and the method for the accurate impedance measurement by measuring the impedance AC voltage (V _IS ) by the constant current (I _S ) are presented.

In the medical diagnosis of edema site, similar to the above, constant current is supplied to the edema site and the principle of diagnosing the condition of edema is measured by measuring the magnitude and phase of the voltage induced from the edema site. Even when noise is mixed into the input signal from the surroundings, only the measurement signal can be separated and measured in the noise voltage, and the same principles and calculations presented in the present invention are performed even when the electrolytic capacitor in the power converter is evaporated and deteriorated. The method can be sufficiently applied as a method for estimating capacitor capacity and diagnosing its deterioration state.

 1 is a conceptual diagram of internal impedance measurement for degradation diagnosis of a battery

2 is a constant current (I _S ) and a voltage drop component (V _IS ) phaser diagram of an object to be measured according to the present invention.

 3 is a conceptual flowchart of the software algorithm of the present invention.

 4 is a conceptual block diagram of the entire system according to the present invention;

 5 is a signal measurement diagram according to the present invention

Claims (9)

In order to measure the effective value of the internal impedance of an object under test, such as a battery or a capacitor, AC constant current (I _S ) is supplied to the inside of the object under test, and AC instantaneous voltage (V _SM ) is measured. In applying the method of measuring the effective value, A means for excluding the AC component value from each operation term including the sum (difference) of the DC component value and the AC component value calculated in the series of calculation processes and extracting only the DC component value. A process of extracting only the DC value of the components constituting each operation term by obtaining the frequency of, calculating the greatest common divisor of all frequencies, and taking a periodic integral for each operation term with an integer multiple of the maximum common divisor. An effective value calculation method of impedance, characterized in that it can be implemented by any electronic device or a programmed software algorithm. In order to measure the effective internal impedance of an object under test, such as a battery or a capacitor, an AC constant current (I _S ) of arbitrary first frequency ω _IS is supplied into the object under test, and an AC instantaneous voltage (V _SM ) is measured. In applying the method of measuring the impedance effective value through the operation of, The measured AC instantaneous voltage V _SM is a noise ripple voltage V _RP composed of arbitrary order frequencies of any second frequency ω and an AC constant current I _S having an arbitrary first frequency ω _IS . And the sum of the impedance voltages V _IS generated by the summation, and the frequencies of all harmonic components constituting the AC instantaneous voltage V _SM are added and subtracted with each other, and the greatest common factor between the results of the addition and subtraction operations. Is determined, and a constant integral period T _D (frequency) is determined as the greatest common divisor or an integer multiple thereof, and for each calculation value composed of a sum (difference) of a DC component value and an AC component value calculated in a series of calculation processes. integration period T _D cycle by performing the integration, and characterized in that only the direct current value easily obtained from the respective calculated values composed of the sum (J) of the direct current component values of an AC component value, any electronic device or a program for Effective value computing method of impedance that may be implemented by the software, localized algorithm. In order to measure the internal impedance effective value of an object under test such as a battery or a capacitor, AC constant current (I _S ) is supplied inside the object under test, and AC instantaneous voltage (V _SM ) is measured to measure the effective impedance through a series of calculations. In applying the method of measuring The measured AC instantaneous voltage (V _SM ) is composed of the sum of the noise ripple voltage (V _RP ) and the impedance voltage (V _IS ), and the noise ripple voltage (V _RP ) is an arbitrary integer multiple of ω, the fundamental frequency of the commercial power supply. The frequency of the AC constant current I _S is determined to be (n + 0.5) times the frequency ω, and a constant integral period T _D (frequency) of (0.5 × ω) is determined. It is determined in the same manner as one period, and the period integration is performed using the integration period T _D in a series of calculation processes, and only a DC value is easily obtained from an operation value composed of a sum of a DC component value and an AC component value. And an effective value calculation method of impedance that can be implemented by any electronic device or a programmed software algorithm. In order to measure the internal impedance effective value of an object under test such as a battery or a capacitor, AC constant current (I _S ) is flowed inside the object under test and the AC instantaneous voltage (V _SM ) is measured. In applying the estimation method, A is measured AC instantaneous voltage (V _SM) is produced by the noise, the ripple voltage (V _RP) and the alternating-current constant current (I _S) consisting only of odd number (odd number) times-order frequency of the fundamental frequency ω of the commercial power supply impedance voltage (V _IS And the frequency of the AC constant current I _S is determined to be the same frequency as a specific even (excellent) order of the commercial power source ω, and the constant integral period T _D is equal to one period of the fundamental frequency ω of the power source. In this case, only the direct current component value is easily obtained from each calculated value consisting of the sum (difference) of the direct current component value and the alternating current component value by performing periodic integration using the integration period T _D in a series of calculation processes. Effective value calculation method of impedance that can be implemented by any electronic device or programmed software algorithm In order to measure the internal impedance effective value of an object under test such as a battery or a capacitor, AC constant current (I _S ) is flowed inside the object under test and the AC instantaneous voltage (V _SM ) is measured. In applying the measuring method, A is measured AC instantaneous voltage (V _SM) is produced by the noise, the ripple voltage (V _RP) and the alternating-current constant current (I _S) consisting only of even number (even number) times-order frequency of the fundamental frequency ω of the commercial power supply impedance voltage (V _IS And the frequency of the AC constant current I _S is determined to be the same frequency as the specific odd (odd) order of ω of the commercial power supply, and the constant integration period T _D is equal to one period of the fundamental frequency ω of the power supply. The same decision is made, and by performing periodical integration using the integration period T _D in a series of calculation processes, it is easy to obtain only a DC component value easily from each calculation value composed of a sum of a DC component value and an AC component value. A method of calculating the effective value of impedance that can be implemented by any electronic device or programmed software algorithm. The method according to claim 2, The frequency ω _IS of the constant current (I _S ) supplied to the object to be measured is selected differently from the frequencies of all harmonic voltages constituting the high frequency ripple voltage (V _RP ), but the frequency ω _IS of the constant current (I _S ) is selected. The frequency ω _IS of the constant current I _S is selected to be equal to the frequency average value of any two adjacent harmonics among each harmonic constituting the high frequency ripple voltage V _RP , and the AC instantaneous voltage V _SM is selected. Frequently adding and subtracting the frequencies of all the harmonic components constituting each other, obtaining a maximum common divisor between the results of the addition and subtraction operation, determining a constant integral period T _D (frequency) as the maximum common divisor, and integrating the period T _D Method for calculating the effective value of the impedance, characterized in that to minimize the operation time by the programmed software algorithm to minimize the. The method according to claim 1, 2, 3, 4 or 5, Any electronic device inputs the basic clock generated from the clock generator 107 to the MPU 101 to make the basic clock necessary for the operation of the MPU 101, divides the basic clock, and divides the divided clock into a constant current. It is a standard to make the frequency of AC constant current (I _S ) by inputting to the circle 102 and minimizes the small error according to individual characteristics by unifying the clock generation circuit which makes the basic clock and the frequency of AC constant current (I _S ). An effective value calculation method of impedance, characterized by the above-mentioned. The method according to claim 1, 2, 3, 4 or 5, The programmed software algorithm initializes all internal variables such as a counter of the MPU 101 through an initialization process of the MPU 101, and generates a constant current I _S by a series of instructions of the MPU 101 ( 102 is operated so that the constant current I _S flows into the measurement object 103, the constant current I _S and the AC instantaneous voltage V _SM are input to the A / D converter 104, and the constant current I _S) and AC instantaneous voltage (V _SM) signal synchronized with sine value and a nose reading a signed value, predetermined integral to the a / D converter 104, an AC instantaneous voltage (V _SM) input is converted to digital through During each period T _D , each reading is performed at each sampling time point ni, ..., n, n + 1, a series of calculation processes are performed, and the corresponding calculation result is accumulated immediately before the calculation result is stored. Is not increased by checking whether the time corresponding to the predetermined integration period T _D (or sampling N times) is reached. Repeat this step, and if it reaches, stops repeating, stops the operation of the constant current source 102 to produce a constant current (I _S ), and accumulates and accumulates for a predetermined period (T _D ) so far. Method for calculating the effective value of the impedance, characterized in that for calculating the average value. The method according to claim 1, 2, 3, 4 or 5, Phase angle of impedance voltage (V _IS ) during a series of calculations And phase of AC constant current (I _S ) The angle is such that the two angles are not as close to 90 degrees but as close to 45 or 135 degrees as possible. The impedance effective value calculation method, characterized in that the value is selected.