JP2023016682A - Test device and test method - Google Patents

Abstract

To make it possible to easily analyze characteristics of a winding to be tested in a shorter time.SOLUTION: A test device 1 includes: a capacitor Cs for impulse voltage application whose one end is connected to an external terminal T2; a switch SW and a current limiting resistor Rs connected in series between the other end of the capacitor Cs for impulse voltage application and an external terminal T1; and a parameter calculation unit 5. The parameter calculation unit 5 calculates at least one of a value of an equivalent capacitor Cd, a value of an equivalent inductor Ld, and a value of an equivalent resistor Rd, by performing a regression analysis using a measured value of a voltage Vcd during an analysis period Ta from when the switch SW is turned on to when resonance based on the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistor Rd related to a winding 11 starts.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a testing apparatus and a testing method, for example, a testing apparatus and a testing method for measuring characteristics of windings of parts and products composed of coils, such as rotating machines such as electric motors and generators, and transformers. Regarding.

Conventionally, as a test device for measuring the characteristics of the windings of rotating machines such as electric motors and generators, based on the change in voltage when an impulse voltage is applied to the windings to be tested, the windings and the test device Impulse winding test device for calculating multiplication value LC (LC value) of inductance L and capacitance C and multiplication value RC (RC value) of resistance (resistance value) R and capacitance C in an equivalent circuit composed of the internal circuit of is known (see Patent Document 1).

Japanese Patent No. 4508211

A conventional impulse winding test apparatus represented by Patent Document 1 can calculate an LC value and an RC value, which are multiplication values of each parameter (inductance L, capacitance C, and resistance value R) related to the winding to be tested. , each parameter cannot be calculated separately. Therefore, for example, when comparing LC or RC values between multiple windings or when measuring the change over time of a single winding, which parameters of the inductance, capacitance, and resistance values are different, or It was not possible to determine which parameter changed over time, and it was not easy to analyze the winding characteristics.

In addition, many of the conventional impulse winding testers have an anti-backflow diode that prevents current from flowing back from the winding side to the internal circuit of the impulse winding tester after applying an impulse voltage to the winding to be tested. It has Such an impulse winding tester is designed to prevent the winding of the test object from being electrically cut off from the internal circuit of the impulse winding tester by the anti-backflow diode after the impulse voltage is applied. LC and RC values are calculated using line-based resonance waveforms. Therefore, it is necessary to measure the resonance waveform after the internal circuit of the impulse winding tester is separated from the winding to be tested by the backflow prevention diode, which poses a problem of long measurement time.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems described above, and an object of the present invention is to make it possible to analyze the characteristics of a winding to be tested more easily in a shorter time.

A test apparatus according to a representative embodiment of the present invention includes a first external terminal to which one terminal of a winding to be tested is connected, and a second external terminal to which the other terminal of the winding is connected. an impulse voltage applying capacitor having one end connected to the second external terminal, a switch connected between the other end of the impulse voltage applying capacitor and the first external terminal, and the impulse voltage applying capacitor a current limiting resistor connected in series with the switch between the other end of the switch and the first external terminal; an instruction input unit for receiving an instruction to start testing; a voltage measuring unit that measures a voltage between the first external terminal and the second external terminal; a storage unit that stores measured value information including the measured value of the voltage measured by the voltage measuring unit; an equivalent inductor connected between an external terminal; an equivalent capacitor connected between the first external terminal and the second external terminal; and an equivalent capacitor connected between the first external terminal and the second external terminal. At least one of the value of the equivalent inductor, the value of the equivalent capacitor, and the value of the equivalent resistance when equivalently represented by an equivalent resistance connected in series with the equivalent inductor is stored in the storage unit. a parameter calculation unit that calculates based on the measured value information, the instruction input unit turns on the switch in response to the instruction to start the test, and the parameter calculation unit is stored in the storage unit. of the voltage in a predetermined period from when the switch is turned on to when resonance based on the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding starts, among the measured value information stored in the At least one of the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value is calculated by performing regression analysis using the measured values.

According to the testing apparatus of the present invention, it is possible to analyze the characteristics of the winding to be tested in a shorter time and more easily.

1 is a diagram showing a configuration of a test device according to Embodiment 1; FIG. 4 is a diagram showing an equivalent circuit when windings to be tested are connected to the testing apparatus according to the first embodiment; FIG. 5 is a diagram showing an example of characteristics of a voltage Vcd across a winding when an impulse voltage is applied between external terminals with the winding connected to the testing apparatus according to the first embodiment; FIG. FIG. 4 is a diagram showing an equivalent circuit of the test apparatus according to Embodiment 1 during analysis period Ta; FIG. 3 is a diagram showing an example of a display screen of the testing device according to Embodiment 1; FIG. 5 is a flow chart showing the flow of a winding analysis method using the testing apparatus according to the first embodiment; FIG. 10 is a diagram showing the configuration of a test apparatus according to Embodiment 2; FIG. 10 is a diagram showing an example of an equivalent circuit based on the impulse voltage generating circuit and windings when the switch is turned on in the testing device according to the second embodiment; FIG. 10 is a diagram showing an example of an equivalent circuit based on the impulse voltage generation circuit and windings after the switch is turned on (t>0) in the testing device according to the second embodiment; 9 is a flow chart showing the flow of a winding analysis method using the testing device according to the second embodiment; FIG. 13 is a diagram showing the configuration of a test apparatus according to Embodiment 3; 5 is a diagram showing an example of the error between the theoretical waveform and the measured waveform of the voltage Vcd when the initial value Vcd| _t=0 of the voltage Vcd is changed; FIG. FIG. 10 is a diagram showing an example of an equivalent inductor Ld when the initial value Vcd| _t=0 of the voltage Vcd is changed; FIG. 10 is a diagram showing an example of an equivalent capacitor Cd when the initial value Vcd| _t=0 of the voltage Vcd is changed; FIG. 10 is a diagram showing an example of an equivalent resistance Rd when the initial value Vcd| _t=0 of the voltage Vcd is changed; 10 is a flow chart showing the flow of a winding analysis method using a testing device according to Embodiment 3;

1. Outline of Embodiment First, an outline of a representative embodiment of the invention disclosed in the present application will be described. In the following description, as an example, reference numerals on the drawings corresponding to constituent elements of the invention are described with parentheses.

[1] A test apparatus (1, 1A, 1B) according to a representative embodiment of the present invention includes a first external terminal (T1) to which one terminal of a winding (11) to be tested is connected; a second external terminal (T2) to which the other terminal of the winding is connected; an impulse voltage applying capacitor (Cs) whose one end is connected to the second external terminal; and the other end of the impulse voltage applying capacitor and the first external terminal, and a current limiting resistor (SW) connected in series with the switch between the other end of the impulse voltage applying capacitor and the first external terminal. Rs), an instruction input unit (3) that receives an instruction to start testing, a voltage measurement unit (4) that measures a voltage (Vcd) between the first external terminal and the second external terminal, and the voltage a storage unit (8) for storing measured value information (81) including the measured value of the voltage measured by the measuring unit; and the winding connected between the first external terminal and the second external terminal. an equivalent inductor (Ld) connected between the first external terminal and the second external terminal, an equivalent capacitor (Cd) connected between the first external terminal and the second external terminal, and the inductor between the first external terminal and the second external terminal At least one of the equivalent inductor value, the equivalent capacitor value, and the equivalent resistance value when equivalently represented by an equivalent resistance (Rd) connected in series with the and a parameter calculation unit (5, 5A, 5B) that calculates based on the measured value information, and the instruction input unit turns on the switch in response to the instruction to start the test, and the parameter calculation unit is, among the measured value information stored in the storage unit, the period from when the switch is turned on until resonance based on the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding starts calculating at least one of the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value by performing a regression analysis using the voltage measurements over a predetermined period of time (Ta) of Characterized by

[2] In the test apparatus described in [1] above, the impulse voltage application capacitor is connected in series with the switch and the current limiting resistor between the other end of the impulse voltage application capacitor and the first external terminal. It may further include a rectifying element (D) for allowing current to pass from the side of the capacitor for applying impulse voltage to the side of the first external terminal and blocking current from the side of the first external terminal to the side of the impulse voltage applying capacitor.

[3] In the test apparatus described in [1] or [2] above, the parameter calculator calculates a maximum point (Pmax) at which the voltage becomes maximum and a minimum point (Pmax) at which the voltage becomes minimum after the switch is turned on. (Pmin), and the period between the maximum point and the minimum point may be set as the predetermined period (Ta).

[4] In the test apparatus (1) according to any one of [1] to [3] above, the parameter calculator (5) performs regression analysis using the voltage measurement values in the predetermined period. Thus, the coefficients of the voltage transient response equation in the equivalent circuit (20) composed of the equivalent inductor, the equivalent capacitor, the equivalent resistor, the impulse voltage applying capacitor, and the current limiting resistor are calculated. , the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance may be calculated based on the calculated coefficients.

[5] In the test apparatus described in [4] above, the transient response equation is an equation obtained by integrating a differential equation expressing the temporal change of the voltage in the equivalent circuit multiple times over time. good too.

[6] In the test apparatus described in [5] above, the transient response equation is an equation obtained by integrating the differential equation three times with respect to time, wherein the value of the equivalent inductor is Ld, the equivalent capacitor Cd is the value of the equivalent resistance, Rd is the value of the equivalent resistance, Cs is the value of the impulse voltage applying capacitor, Rs is the value of the current limiting resistance, and the voltage between the first external terminal and the second external terminal is Assuming that Vcd and time are t, the expression obtained by integrating three times may be expressed by the following expression (2).

[7] In the test apparatus described in [5] above, the transient response equation is an equation obtained by integrating the differential equation twice with respect to time, wherein the value of the equivalent inductor is Ld, the equivalent capacitor Cd is the value of the equivalent resistance, Rd is the value of the equivalent resistance, Cs is the value of the impulse voltage applying capacitor, Rs is the value of the current limiting resistance, and the voltage between the first external terminal and the second external terminal is Assuming that Vcd and time are t, the expression obtained by performing the integration twice may be expressed by the following expression (11).

[8] In the test apparatus (1) according to any one of [4] to [7] above, the value of the equivalent capacitor, the value of the equivalent inductor, and the value of the equivalent resistance calculated by the parameter calculator. a waveform generator (6) for generating a theoretical waveform (310) of the voltage by numerical integration using the transient response equation to which the A display unit (7) for displaying a measured waveform (300) of the voltage measured by the voltage measurement unit may be further provided.

[9] In the test apparatus (1A, 1B) described in [1] or [2] above, the parameter calculator (5A, 5B) calculates the initial value of the voltage (Vcd| _t=0 ) coincides with the voltage obtained by dividing the charge voltage (Cs) of the impulse voltage application capacitor by the impulse voltage application capacitor (Vcs) and the equivalent capacitor (Cd), the impulse voltage application The value of the equivalent capacitor is calculated based on the equation representing the relationship between the capacitor and the equivalent capacitor and the measured value information stored in the storage unit, and the parameter calculation unit calculates the By performing a regression analysis using the voltage measurement values, the transient response of the voltage in the equivalent circuit (22) composed of the equivalent inductor, the equivalent resistance, the impulse voltage applying capacitor, and the current limiting resistor. The coefficients of the equation may be calculated, and the equivalent inductor value and the equivalent resistance value may be calculated based on the calculated coefficients and the initial value of the voltage.

[10] In the test apparatus (1B) described in [9] above, the value of the equivalent capacitor, the value of the equivalent inductor, and the value of the equivalent resistance calculated by the parameter calculation unit (5B) are applied to the A waveform generation unit (6) for generating a theoretical waveform of the voltage by numerically integrating using a transient response equation, the theoretical waveform generated by the waveform generation unit and the voltage measured by the voltage measurement unit and an error calculator (9) for calculating an error from the measured waveform of the voltage, wherein the parameter calculator calculates the value of the equivalent capacitor and the value of the equivalent inductor that minimizes the error, and the The equivalent resistance value may be the analysis result of the winding.

[11] In the test apparatus described in [9] or [10] above, the transient response equation is an equation obtained by integrating a differential equation representing temporal changes in the voltage of the equivalent circuit with respect to time. There may be.

[12] In the test apparatus described in [11] above, the value of the equivalent inductor is Ld, the value of the equivalent capacitor is Cd, the value of the equivalent resistance is Rd, the value of the impulse voltage applying capacitor is Cs, and the When the value of the current limiting resistor is Rs, the voltage between the first external terminal and the second external terminal is Vcd, and the time is t, the transient response equation is the differential equation from time t=0 to time It is a formula obtained by integrating up to t=a (a>0), and may be expressed by formula (21) or formula (22) described later.

[13] A method according to a representative embodiment of the present invention comprises: a first external terminal (T1) to which one terminal of a winding (11) to be tested is connected; a connected second external terminal (T2), an impulse voltage applying capacitor (Cs) one end of which is connected to the second external terminal, the other end of the impulse voltage applying capacitor and the first external terminal A test device ( It is a test method using 1). The test method includes a first step (S4) of turning on the switch, a second step (S5) of measuring the voltage between the first external terminal and the second external terminal, and the winding, an equivalent inductor (Ld) connected between the first external terminal and the second external terminal; an equivalent capacitor (Cd) connected between the first external terminal and the second external terminal; The value of the equivalent inductor and the value of the equivalent capacitor when equivalently represented by an equivalent resistance (Rd) connected in series with the equivalent inductor between the first external terminal and the second external terminal , and a third step (S5 to S7, S7A, S8A) of calculating the value of the equivalent resistance based on the measured value of the voltage measured in the second step. The third step measures the voltage during a predetermined period (Ta) from when the switch is turned on until resonance based on the inductor, the capacitor, and the resistance of the winding is started. and calculating at least one of the equivalent inductor value, the equivalent capacitor value, and the equivalent resistance value (S6, S7, S7A, S8A) by performing regression analysis using do.

2. Specific Examples of Embodiments Specific examples of embodiments of the present invention will be described below with reference to the drawings. In the following description, constituent elements common to each embodiment are denoted by the same reference numerals, and repeated descriptions are omitted.

<<Embodiment 1>>
FIG. 1 is a diagram showing the configuration of a test apparatus 1 according to Embodiment 1. As shown in FIG.
A test apparatus 1 shown in FIG. 1 is an apparatus for measuring the characteristics of windings (coils) constituting rotating machines such as electric motors and generators, and electrical equipment such as transformers. For example, the test apparatus 1 determines at least one value of an equivalent inductor, an equivalent capacitor, and an equivalent resistance, which are parameters related to the winding under test, based on changes in voltage when an impulse voltage is applied to the winding under test. It is an impulse winding test device that calculates

As shown in FIG. 1, the test apparatus 1 includes external terminals T1 and T2, an impulse voltage generation circuit 2, an instruction input section 3, a voltage measurement section 4, a parameter calculation section 5, a waveform generation section 6, a display section 7, and a memory. has part 8;

The external terminals T1 and T2 are terminals for connecting a winding 11 as a device under test (DUT). For example, one terminal of the winding 11 is connected to the external terminal T1, and the other terminal of the winding 11 is connected to the external terminal T2.

The impulse voltage generating circuit 2 is a circuit for applying a desired impulse voltage to the winding 11 under test connected between the external terminals T1 and T2. The impulse voltage generation circuit 2 has, for example, an impulse voltage application capacitor Cs, a switch SW, and a current limiting resistor Rs.

The impulse voltage application capacitor Cs is a capacitor that charges an electric charge for generating the impulse voltage E. As shown in FIG. One end of the impulse voltage applying capacitor Cs is connected to the external terminal T2.

The switch SW is an element for switching whether to output the impulse voltage E or not. The switch SW is realized by, for example, a semiconductor element such as a power transistor or a thyristor. The switch SW is connected between the other end of the impulse voltage applying capacitor Cs and the external terminal T1.

The current limiting resistor Rs is an element for limiting the current flowing from the external terminal T1 to the winding 11 under test when the impulse voltage applying capacitor Cs is discharged. The current limiting resistor Rs is connected in series with the switch SW between the other end of the impulse voltage applying capacitor Cs and the external terminal T1.

The rectifying element D is an element that passes a current from the impulse voltage applying capacitor Cs side to the external terminal T1 side and cuts off a current from the external terminal T1 side to the impulse voltage applying capacitor Cs side. The rectifying element D is, for example, a diode. In addition, in the following description, the rectifying element D is also written as the "backflow prevention diode D."

The backflow prevention diode D is connected in series with the switch SW and the current limiting resistor Rs between the other end of the impulse voltage applying capacitor Cs and the external terminal T1. For example, the anode electrode of the backflow prevention diode D is connected to one end of the current limiting resistor Rs, and the cathode electrode of the backflow prevention diode D is connected to the external terminal T1.

The impulse voltage generation circuit 2 outputs an impulse voltage E between one end of the current limiting resistor Rs and the external terminal T2 via the switch SW in accordance with an instruction from the instruction input unit 3. FIG.
For example, first, the impulse voltage application capacitor Cs is charged by a DC power supply (not shown) so that the voltage of the impulse voltage application capacitor Cs becomes the impulse voltage E. Then, as shown in FIG. Next, the switch SW is turned on according to the instruction from the instruction input section 3 . As a result, the charge stored in the impulse voltage applying capacitor Cs is discharged through the current limiting resistor Rs and the backflow prevention diode D, and a voltage Vcd is generated between the external terminals T1 and T2.

The instruction input unit 3 is a functional unit that receives instructions to the test apparatus 1 . The instruction input unit 3 is implemented by, for example, an input interface device such as an operation button or a touch panel for receiving an operation of the test apparatus 1 by the user, and program processing by the CPU. When the user inputs test conditions such as the value of the impulse voltage E and a sampling frequency to be described later, the instruction input unit 3 stores the input values in the storage unit 8, thereby providing the test conditions to the test apparatus 1. set. In addition, the instruction input unit 3 turns on the switch SW of the impulse voltage generation circuit 2 in response to the user inputting an instruction to start the test.

The voltage measurement unit 4 is a functional unit that measures the voltage (inter-terminal voltage) Vcd between the external terminal T1 and the external terminal T2. Voltage measurement unit 4 stores measurement value information 81 including the measurement value of voltage Vcd in storage unit 8 .

Specifically, the voltage measurement unit 4 acquires the measured value of the voltage Vcd by sampling the voltage Vcd at a predetermined sampling period. The voltage measurement unit 4 includes, for example, a resistance voltage dividing circuit that divides the voltage Vcd between the external terminal T1 and the external terminal T2, and converts the voltage divided by the resistance voltage dividing circuit into a digital signal at a predetermined sampling period. and an A/D conversion circuit. The voltage measurement unit 4 acquires time-series data of the measured value (sampling data) of the voltage Vcd by, for example, sampling the voltage Vcd at a predetermined sampling period, and stores the time-series data as measured value information 81 in the storage unit 8 .

The parameter calculator 5 is a functional unit that calculates the values of the equivalent capacitor, equivalent inductor, and equivalent resistance as parameters for the winding 11 to be tested. The waveform generation unit 6 is a functional unit for generating various waveform data indicating characteristics such as voltage and current related to the winding 11 to be tested. Detailed functions of the parameter calculator 5 and the waveform generator 6 will be described later.

The storage unit 8 is a functional unit for storing programs and various parameters for the test apparatus 1 to function as an impulse winding test apparatus, test results of the winding 11 to be tested, and the like. The storage unit 8 stores, for example, mathematical formula information 82, analysis result information 83, measured waveform data 84, theoretical waveform data 85, etc., which will be described later, in addition to the above-described measured value information 81. FIG.

The parameter calculation unit 5, the waveform generation unit 6, and the storage unit 8 described above are implemented by, for example, a program processing device. Specifically, a processor such as a CPU, various storage devices such as RAM and ROM, a counter (timer), an A/D conversion circuit, a D/A conversion circuit, a clock generation circuit, an input/output I/F circuit, etc. In a program processing device (such as a microcontroller) having a configuration in which peripheral circuits are connected to each other via a bus or a dedicated line, the processor executes various arithmetic processing according to the program stored in the memory, and the processing result is The functional blocks described above are realized by controlling peripheral circuits such as an A/D conversion circuit and an input/output interface circuit.

The display unit 7 is a functional unit that displays information for setting test conditions, information on test results, and the like. The display unit 7 is realized by, for example, a display device such as a liquid crystal display.

As an analysis of the characteristics of the winding 11 to be tested, the test apparatus 1 analyzes the voltage Vcd between the external terminals T1 and T2 when the impulse voltage E is applied to the winding 11 connected between the external terminals T1 and T2. At least one value of an equivalent inductor, an equivalent capacitor, and an equivalent resistance, which are parameters related to the winding 11, is calculated based on the transient response characteristics.

A specific method of calculating each parameter related to the winding 11 to be tested by the test apparatus 1 will be described below.

FIG. 2 is a diagram showing an equivalent circuit when the winding 11 to be tested is connected to the test apparatus 1 according to the first embodiment.
FIG. 3 shows an example of the characteristics of the voltage Vcd across the winding 11 when an impulse voltage is applied between the external terminals T1 and T2 with the winding 11 connected to the testing apparatus 1 according to the first embodiment. FIG. 4 is a diagram showing;

In FIG. 3, the horizontal axis represents elapsed time [μs], and the vertical axis represents voltage [V]. FIG. 3 shows temporal changes in the voltage Vcd after the impulse voltage application capacitor is charged so that the impulse voltage E becomes 1000 V and the switch SW is turned on.

As shown in FIG. 2, the circuit when the winding 11 side is viewed from the external terminals T1 and T2 includes an equivalent inductor Ld connected between the external terminal T1 and the external terminal T2, and an external terminal T1 and the external terminal T2, and an equivalent resistor Rd connected in series with the equivalent inductor Ld between the external terminals T1 and T2.

As shown in FIG. 3, when the switch SW of the impulse voltage generating circuit 2 is turned on, the charge of the impulse voltage applying capacitor Cs moves through the current limiting resistor Rs and the backflow prevention diode D, and the equivalent current on the winding 11 side is reduced. Capacitor Cd is charged.

When the switch SW is turned on at time t=0 s, no current flows through the equivalent inductor Ld on the winding 11 side immediately after the switch SW is turned on. Therefore, the voltage Vcd between the external terminals T1 and T2 rises to about 1000 V, which is the charging voltage (impulse voltage E) of the impulse voltage applying capacitor Cs. However, the degree to which voltage Vcd rises varies depending on the characteristics of winding 11 .

After that, the current starts to flow through the equivalent resistor Rd to the equivalent inductor Ld, and the voltage Vcd drops. When the voltage Vcd drops to about -1000 V, the impulse voltage generating circuit 2 and the circuit on the winding 11 side are electrically isolated by the backflow prevention diode D. FIG. As a result, around time t=10 μs in FIG. 3, the resonance of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd on the winding 11 side starts, and the voltage Vcd oscillates attenuated. After that, the voltage Vcd finally becomes 0V. However, the extent to which the voltage Vcd drops and the time at which it drops varies greatly depending on the characteristics of the winding 11 .

As described above, the conventional impulse winding tester determines parameters for the winding under test based on measurements of the voltage Vcd during the period Tx of resonance due to the equivalent inductor, equivalent capacitor, and equivalent resistance of the winding. LC and RC values, which are multiplication values, were calculated.

On the other hand, in the test apparatus 1 according to the first embodiment, as shown in FIG. 3, after the switch SW is turned on, resonance is started by the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd on the winding side. The analysis period is a predetermined period Ta until the analysis period Ta, and the equivalent inductor Ld, the equivalent inductor Ld, the equivalent Values of capacitor Cd and equivalent resistance Rd are calculated.

FIG. 4 is a diagram showing an equivalent circuit of the test apparatus 1 according to Embodiment 1 during the analysis period Ta.

FIG. 4 shows an equivalent circuit 20 composed of the impulse voltage generating circuit 2 and the winding 11 during the analysis period Ta, that is, the period during which the switch SW is turned on and forward current flows through the anti-backflow diode D. there is 4, illustration of the switch SW and the backflow prevention diode D is omitted.

When the on-resistance of the switch SW, the on-resistance of the anti-backflow diode D, and the forward voltage drop are ignored, the impulse voltage generation circuit 2 during the period in which the switch SW is turned on and the forward current flows through the anti-backflow diode D is: As shown in FIG. 4, it is equivalently represented by a current limiting resistor Rs and an impulse voltage applying capacitor Cs connected in series between the external terminals T1 and T2.

In the equivalent circuit 20 shown in FIG. 4, the equation representing the temporal change (transient response) of the voltage Vcd between the external terminals T1 and T2 after the switch SW is turned on is expressed by the following equation (1).

In the analysis period Ta shown in FIG. 3, based on the premise that the transient response of the voltage Vcd is represented by the above equation (1), regression analysis (for example, the least square method ) and calculating the coefficients of the respective terms of the above equation (1), the values of the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd relating to the winding 11 to be inspected can be derived.

On the other hand, when the observed waveform (measured value) of the voltage Vcd contains a noise component, the above equation (1) includes a three-fold derivative term. Even if the smoothing process is performed, there is a possibility that the noise component cannot be sufficiently removed.

Therefore, the test apparatus 1 according to the first embodiment uses an equation obtained by integrating the above equation (1) multiple times with respect to time t as an equation of the transient response of the voltage Vcd, using the equivalent inductor Ld, the equivalent capacitor Each value of Cd and equivalent resistance Rd may be calculated.

Here, as an example, a case of using an equation obtained by integrating equation (1) three times with respect to time t will be described.

By integrating equation (1) three times over time t and using the initial conditions to determine the constant of integration, equation (2) below is obtained. Also, the coefficients of the terms in the following formula (2) are replaced with V, W, X, Y, and Z, respectively, as in the following formulas (3) to (7).

Since the above equation (2) does not have a differential term, it is not necessary to perform smoothing processing on the measured value of the voltage Vcd. Moreover, since the above equation (2) has an integral term, it is possible to suppress the influence of noise. Furthermore, since the above formula (2) has more coefficients than the above formula (1), it becomes easier to specify the parameters (Ld, Cd, Rd).

A method of calculating parameters (circuit constants) using the above equation (2) is as follows.
First, the parameter calculator 5 of the test apparatus 1 determines the analysis range Ta. For example, as shown in FIG. 3, the parameter calculator 5 detects a maximum point Pmax at which the voltage Vcd is maximum and a minimum point Pmin at which the voltage Vcd is minimum after the switch SW is turned on. The parameter calculator 5 sets the period between the maximum point Pmax and the minimum point Pmin as the analysis period Ta, and sets the time when the switch SW is turned on as t=0.

Here, the maximum point Pmax and the minimum point Pmin may be the maximum point and the minimum point of a measured waveform based on the time-series data of the voltage Vcd measured by the voltage measurement unit 4, or the voltage Vcd measured by the voltage measurement unit 4. may be the maximum and minimum points of a smoothed waveform after performing smoothing processing on the time-series data of the measured values of .

を夫々算出する。また、パラメータ算出部５は、電圧測定部４のサンプリング周期に基づいてｔおよびｔ^２を算出する。パラメータ算出部５は、これらの算出した値を用いて、公知の回帰分析手法（例えば、最小二乗法）により正規方程式を作成し、例えば逆行列やＬＵ分解法等の演算を行うことにより、上記式（２）の各項の係数Ｖ～Ｚを求める。 Next, the parameter calculator 5 uses the data of the measured value of the voltage Vcd in the analysis period Ta,

are calculated respectively. Also, the parameter calculation unit ⁵ calculates t and t2 based on the sampling period of the voltage measurement unit 4 . The parameter calculation unit 5 uses these calculated values to create a normal equation by a known regression analysis method (for example, the least squares method), and performs calculations such as the inverse matrix and the LU decomposition method to obtain the above Obtain the coefficients V to Z of each term in equation (2).

Next, the parameter calculator 5 calculates the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd based on the calculated coefficients V to Z and the above equations (3) to (7).

First, the method of calculating the value of the equivalent inductor Ld is as follows.
For example, from the above equation (6), the value of the equivalent inductor Ld is expressed by the following equation (8).

Here, the impulse voltage E is a known value because it is a value set before the test is performed using the test apparatus 1 . In addition, the value of the impulse voltage applying capacitor Cs is set when the test apparatus 1 is designed, and is known. Therefore, the parameter calculator 5 calculates the value of the equivalent inductor Ld by substituting the values of Cs, E, and Y into the above equation (8).

Next, the calculation method of the equivalent resistance Rd is as follows.
For example, from the above equation (7), the value of the equivalent resistance Rd is represented by the following equation (9).

The parameter calculator 5 calculates the value of the equivalent resistance Rd by substituting the previously obtained values of Ld and Z into the above equation (9).

Finally, the method of calculating the value of the equivalent capacitor Cd is as follows.
The value of the equivalent capacitor Cd may be calculated using any one or a combination of equations (3), (4) and (5) for the coefficients V, X and Z. On the other hand, the above formulas (3) to (5) include the value of the current limiting resistor Rs. Although the value of the current limiting resistor Rs itself is known, in practice, the impulse voltage generating circuit 2 has the switch SW and the anti-backflow diode D connected in series with the current limiting resistor Rs as described above. Between the equivalent capacitor Cd and the external terminal T1, not only the current limiting resistor Rs but also their ON resistance and forward voltage drop exist.

Therefore, the value of the voltage Vcd measured by the test apparatus 1 is affected by the ON resistances of the current limiting resistor Rs, the switch SW, and the backflow prevention diode D, and the like. Therefore, when the value of the equivalent capacitor Cd is calculated by directly substituting the value of the known current limiting resistor Rs into the equations (3), (4), and (5), the estimated value of the equivalent capacitor Cd is will contain an error component based on

Therefore, in order to minimize the effect of the error based on the on-resistance and the like, the test apparatus 1 according to the first embodiment uses the coefficient W Equation (4) may be used.
For example, from the above equation (4), the value of the equivalent capacitor Cd is represented by the following equation (10).

The parameter calculation unit 5 calculates the value of the equivalent capacitor Cd by substituting the previously obtained values of Ld, Rd, and W and the known values of Cs, E, and Rs into the above equation (10). good.

The parameter calculation unit 5 stores the calculated values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd regarding the winding 11 to be inspected in the storage unit 8 as the analysis result information 83 .

Here, information required for the above calculation by the parameter calculator 5 may be stored in the storage unit 8 in advance. For example, a program for calculating the coefficients V, W, X, Y, Z from the measured value of the voltage Vcd, the information of the above formulas (3) to (7), the value of the current limiting resistor Rs, and the impulse voltage applying capacitor The value of Cs and the like may be stored in the storage unit 8 in advance as the mathematical expression information 82 . In addition, the value of the impulse voltage E set by the user at the start of the test is also stored in the storage unit 8 .
As a result, the parameter calculation unit 5 uses the mathematical expression information 82 stored in the storage unit 8 and the value of the impulse voltage E set at the start of the test to calculate the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd can be calculated.

In the above description, the parameter calculator 5 calculates the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd based on the equation (2) obtained by integrating the equation (1) three times. Although the case is exemplified, the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd may be obtained based on the equation obtained by integrating Equation (1) twice. A method of calculating the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd using equations obtained by integrating twice will be described below.

By integrating equation (1) above twice for time t and determining the constant of integration using the initial conditions, equation (11) below is obtained. Also, the coefficients of the terms of the following formula (11) are replaced with V, W, X, Y, and Z, respectively, as in formulas (12) to (16) below.

Equation (11) above has one differential term and a plurality of integral terms, so that the influence of noise can be suppressed. Comparing the coefficients of each term in the above-described equation (2) when integrating three times with the coefficients of each term in the above equation (11) when integrating twice, only "Z" is different.

A method of calculating parameters (circuit constants) using the above equation (11) is as follows.
First, the parameter calculator 5 of the test apparatus 1 determines the analysis range Ta. The method of determining the analysis range Ta is the same as in the case of using Equation (2) described above.

を算出する。また、パラメータ算出部５は、電圧測定部４のサンプリング周期に基づいてｔを算出する。パラメータ算出部５は、これらの算出した値を用いて、公知の回帰分析手法により正規方程式を作成し、例えば逆行列やＬＵ分解法等の演算を行うことにより、上記式（１１）の各項の係数Ｖ～Ｚを求める。 Next, the parameter calculator 5 uses the data of the measured value of the voltage Vcd in the analysis period Ta,

Calculate Also, the parameter calculation unit 5 calculates t based on the sampling period of the voltage measurement unit 4 . The parameter calculation unit 5 uses these calculated values to create a normal equation by a known regression analysis method, for example, by performing calculations such as inverse matrix and LU decomposition method, each term of the above equation (11) Calculate the coefficients V to Z of .

Next, the parameter calculator 5 calculates the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd based on the calculated coefficients V to Z and the above equations (12) to (16).

First, the method of calculating the value of the equivalent inductor Ld is as follows.
For example, from the above equation (15), the value of the equivalent inductor Ld is represented by the following equation (17).

Here, as described above, the values of the impulse voltage E and the impulse voltage application capacitor Cs are known. Therefore, the parameter calculator 5 calculates the value of the equivalent inductor Ld by substituting the values of Cs, E, and Y into the above equation (17).

Next, the calculation method of the equivalent resistance Rd is as follows.
For example, from the above equation (16), the value of the equivalent resistance Rd is represented by the following equation (18).

The parameter calculator 5 calculates the value of the equivalent resistance Rd by substituting the previously obtained values of Ld and Z into the above equation (18).

The equivalent capacitor Cd can be calculated by the parameter calculator 5 using any one of the above equations (12) to (14), as in the above-described case of using the equation (2) in which integration is performed three times.

As described above, the parameter calculator 15 not only integrates equation (1) three times over time t to obtain equation (2), but also integrates equation (1) twice over time t. It is also possible to find the respective values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd based on equation (11).

In addition to the function of individually calculating the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd related to the winding 11 to be inspected, the test apparatus 1 according to the embodiment also calculates the calculated equivalent inductor Ld, the equivalent It has a function of displaying a theoretical waveform of voltage Vcd based on the values of capacitor Cd and equivalent resistance Rd. This function will be described in detail below.

In the test apparatus 1 shown in FIG. 1, the waveform generation unit 6 detects temporal changes in the voltage Vcd based on the time-series data (measurement value information 81) of the measured value of the voltage Vcd measured by the voltage measurement unit 4. is generated and stored in the storage unit 8 as measured waveform data 84 .

Further, the waveform generation unit 6 calculates the transient response equation (equation (1)) based on the respective values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd (analysis result information 83) calculated by the parameter calculation unit 5. is used to generate a theoretical waveform representing the temporal change of the voltage Vcd in the equivalent circuit 20 and stored in the storage unit 8 as theoretical waveform data 85 .

Based on the measured waveform data 84 and the theoretical waveform data 85 generated by the waveform generation section 6, the display section 7 displays a waveform related to the voltage Vcd on the screen.

FIG. 5 is a diagram showing an example of the display screen of the test device 1 according to the first embodiment.
As shown in FIG. 5 , the test apparatus 1 includes a display 70 as means for realizing the function of the display section 7 . The test apparatus 1 displays information for setting test conditions, information on test results, and the like on the screen of the display 70 . For example, the display 70 is equipped with a touch panel, and a part of the functions of the instruction input unit 3 is implemented by the display 70 . For example, the user can set test conditions and the like by touching the screen of the display 70 .

Moreover, the test apparatus 1 may have various physical buttons as means for realizing a part of the functions of the instruction input section 3 . For example, as shown in FIG. 5, the test apparatus 1 includes a start button (power button) 30 for starting the test apparatus 1, a start button 31 for starting the test, a stop button 32 for stopping the test, and the like. may have

The display unit 7 displays the measured waveform 300 and the theoretical waveform 310 of the voltage Vcd on the screen of the display 70 based on the measured waveform data 84 and the theoretical waveform data 85 stored in the storage unit 8 . For example, as shown in FIG. 5, the display unit 7 displays the measured waveform 300 and the theoretical waveform 310 of the voltage Vcd together on the screen of the display 70 of the display. For example, the display unit 7 may display the measured waveform 300 and the theoretical waveform 310 in an overlapping manner as shown in FIG.

Further, the display unit 7 may immediately display the measured waveform 300 and the theoretical waveform 310 on the display 70 after calculating the parameters (Ld, Cd, Rd). , the measured waveform 300 and the theoretical waveform 310 may be displayed on the display 70 . Moreover, the display unit 7 may display only one of the measured waveform 300 and the theoretical waveform 310 on the display 70 .

Next, a flow of a method for analyzing the winding 11 to be tested using the test apparatus 1 according to the first embodiment will be described.

FIG. 6 is a flow chart showing the flow of the method for analyzing the winding 11 using the testing apparatus 1 according to the first embodiment.

For example, after the user operates the activation button 30 to activate the test apparatus 1, the user sets the test conditions and the like in the test apparatus 1 by performing a touch operation on the display 70 as the instruction input unit 3 (step S1). . For example, the user sets the value of the impulse voltage E, the sampling period (sampling frequency) for measuring the voltage Vcd, etc. in the test apparatus 1 .

In the initial state after the test apparatus 1 is activated, the switch SW of the impulse voltage generation circuit 2 is in the OFF state.

Next, the user connects the winding 11 to be tested between the external terminals T1 and T2 of the test apparatus 1 (step S3). Note that the winding 11 may be connected to the testing apparatus 1 before step S1.

Next, the test apparatus 1 determines whether or not the user has input a test execution instruction (step S3). For example, if the start button 31 is not operated by the user (step S3: NO), the test apparatus 1 waits until the start button 31 is operated.

When the start button 31 is operated (step S3: YES), the test apparatus 1 outputs the impulse voltage E between one end of the current limiting resistor Rs and the external terminal T2 via the switch SW (step S4). Specifically, in response to an instruction from the instruction input unit 3, the impulse voltage generation circuit 2 controls the impulse voltage application capacitor so that the voltage of the impulse voltage application capacitor becomes the impulse voltage E set in step S1. Cs is charged by a DC power supply (not shown). Next, the impulse voltage generating circuit 2 turns on the switch SW. Thereby, the voltage Vcd is applied between the external terminals T1 and T2.

Also, the test apparatus 1 starts measuring the voltage Vcd between the external terminals T1 and T2, for example, simultaneously with step S4 (step S5). Specifically, as described above, the voltage measurement unit 4 measures the voltage Vcd between the external terminals T1 and T2 based on the sampling period set in step S1, and obtains the time-series data of the measured value of the voltage Vcd. The measured value information 81 is stored in the storage unit 8 .

Next, the parameter calculator 5 determines the analysis range Ta (step S6). Specifically, the parameter calculator 5 detects the maximum point Pmax and the minimum point Pmin of the voltage Vcd based on the time-series data of the measured value of the voltage Vcd acquired in step S5 by the method described above, and A period between the point Pmax and the minimum point Pmin is defined as an analysis period Ta.

Next, the parameter calculation unit 5 uses the measurement value of the voltage Vcd within the analysis period Ta set in step S6 and the mathematical expression information 82 stored in the storage unit 8 to calculate the The values of equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd are calculated (step S7).

Next, the waveform generator 6 generates the measured waveform data 84 based on the measured value of the voltage Vcd obtained in step S5, and the equivalent inductor Ld related to the winding 11 calculated in step S7 by the above-described method. , equivalent capacitor Cd, and equivalent resistance Rd are used to generate theoretical waveform data 85 (step S8).

Next, based on the measured waveform data 84 and the theoretical waveform data 85 generated in step S9, the display unit 7 displays, for example, the measured waveform 300 and the theoretical waveform 310 superimposed on the screen of the display 70 of the test apparatus 1. (step S9).

Note that the above-described waveform data generation processing (step S8) and waveform display processing (step S9) are executed when, for example, the user operates the test apparatus 1 and the instruction input unit 3 receives a waveform display instruction from the user. It may be executed only when

As described above, in the test apparatus 1 according to the first embodiment, the winding 11 to be tested connected between the external terminal T1 and the external terminal T2 is connected between the external terminal T1 and the external terminal T2. An inductor Ld, an equivalent capacitor Cd connected between the external terminals T1 and T2, and an equivalent resistance Rd connected in series with the equivalent inductor Ld between the external terminals T1 and T2 The value of the equivalent inductor Ld, the value of the equivalent capacitor Cd, and the value of the equivalent resistance Rd are calculated based on the measured value of the voltage Vcd between the external terminals T1 and T2 measured by the voltage measuring unit 4 It has a parameter calculator 5 for calculating.

Of the measured value information 81 stored in the storage unit 8, the parameter calculation unit 5 determines that after the switch SW is turned on, resonance based on the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd on the winding 11 side starts. At least one value of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd is calculated by performing regression analysis using the measured value of the voltage Vcd in a predetermined period (analysis period Ta) until the .

According to this, like a conventional impulse winding tester, the measured value (measured waveform ), but the measured value of the voltage Vcd before the resonance starts, it is possible to start the analysis process of the winding 11 more quickly.

Further, as described above, the conventional impulse winding tester uses the equation and the measured value of the voltage Vcd at resonance due to the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd on the winding 11 side, so the LC value and the multiplied value of each parameter such as the RC value. On the other hand, the test apparatus 1 according to the first embodiment performs calculations based on the equation of the transient response of the voltage Vcd in the equivalent circuit before resonance starts. can be calculated separately.

Thus, according to the test apparatus 1 according to Embodiment 1, it is possible to analyze the characteristics of the winding to be tested more easily in a shorter time.

Further, in the test apparatus 1 according to the first embodiment, the parameter calculation unit 5 detects the maximum point Pmax at which the voltage Vcd becomes maximum and the minimum point Pmin at which the voltage Vcd becomes minimum after the switch SW is turned on, and A period between the maximum point Pmax and the minimum point Pmin is defined as an analysis period Ta.
According to this, it is possible to easily determine the analysis period Ta for which the transient response equation based on the equivalent circuit 20 can be applied.

In the test apparatus 1, the switch SW and the current limiting resistor Rs are connected in series between the other end of the impulse voltage applying capacitor Cs and the external terminal T1, and the current from the impulse voltage applying capacitor Cs side to the external terminal T1 side is connected. A backflow prevention diode D may be provided as a rectifying element that allows a current to flow and blocks the current from the external terminal T1 side to the impulse voltage applying capacitor Cs side.
According to this, it is possible to clearly separate the analysis period Ta described above by the test apparatus 1 from the resonance period Tx by the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd on the winding 11 side. By observing the measured waveform of the voltage Vcd, it becomes possible to easily determine at what timing the resonance by the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd begins.

In addition, the parameter calculation unit 5 performs regression analysis using the measured values of the voltage Vcd in a predetermined period of time (analysis period Ta) to determine the equivalent inductor Ld, the equivalent capacitor Cd, the equivalent resistance Rd, and the impulse voltage Calculate the coefficients of the equation of the transient response of the voltage Vcd in the equivalent circuit (see FIG. 4) configured by the application capacitor Cs and the current limiting resistor Rs, and based on the calculated coefficients, the value of the equivalent capacitor Cd and the equivalent inductor Calculate the value of Ld and the equivalent resistance Rd.
According to this, it becomes possible to calculate each value of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd more accurately.

Further, the equation of the transient response of the equivalent circuit 20 used for the analysis of the winding 11 described above by the test apparatus 1 is a differential equation (equation (1)) expressing the temporal change of the voltage Vcd in the equivalent circuit 20 multiple times. It may be a formula obtained by integration.

As described above, the above equation (1) representing the transient response of the voltage Vcd in the equivalent circuit 20 includes a three-fold differentiation term. The included noise component may be emphasized. On the other hand, the test apparatus 1 according to the first embodiment can reduce the differential term by using the expression obtained by integrating the above expression (1) multiple times, and the noise component included in the waveform of the measured voltage Vcd can be reduced. It is possible to suppress the influence of

For example, by using the above equation (11) obtained by integrating the above equation (1) twice, the differential term can be reduced, so that the noise component contained in the measured value of the voltage Vdc can be effectively suppressed. . Further, by using the above equation (2) obtained by integrating the above equation (1) three times, the differential term can be further reduced, so that the noise component contained in the measured value of the voltage Vdc can be suppressed more effectively. can be done.

It is also possible to use an equation obtained by integrating the above equation (1) once.

Furthermore, the test apparatus 1 according to the first embodiment calculates the transient A waveform generator 6 that generates a theoretical waveform of the voltage Vcd by performing numerical integration using the response equation, a theoretical waveform 310 generated by the waveform generator 6, and the voltage Vcd measured by the voltage measurement unit 4. It has a display unit 7 for displaying the measured waveform 300 .

According to this, the user can visually compare the measured waveform 300 actually measured and the theoretical waveform 310 obtained by the analysis. It can be easily determined whether or not equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd) have appropriate values.

<<Embodiment 2>>
FIG. 7 is a diagram showing the configuration of a test apparatus 1A according to Embodiment 2. As shown in FIG.

In general, when the winding under test has a core, the iron loss of the core increases the attenuation of the waveform. In addition, when a high voltage is applied to the winding, magnetic saturation occurs in the core, and parameters such as the inductance of the winding greatly change, resulting in strong nonlinearity.

As described above, the conventional impulse winding tester uses the waveform of the resonance phenomenon after the internal circuit of the impulse winding tester is separated from the winding to be tested by the backflow prevention diode. Since the values and RC values are calculated, if the waveform is attenuated, the parameter calculation error increases. Moreover, when magnetic saturation occurs, the nonlinearity of the parameters increases, and there is a possibility that the obtained parameters are inappropriate values.

Also, when the configuration of the coil to be tested is complicated, ringing or local large fluctuations may occur in the response waveform, and the calculated winding-related parameters may become inappropriate values. In such a case, the winding-related parameters may have negative values, or may have values that deviate greatly from the actual parameter values.

Therefore, the test apparatus 1A according to the second embodiment uses a simpler equivalent circuit in an analysis period in which attenuation is small, thereby reducing unknowns in regression analysis and preventing errors due to small waveform amplitudes. While avoiding this, it is made difficult to calculate an inappropriate value as a parameter related to the winding.

The test apparatus 1A shown in FIG. 7 calculates the value of the equivalent inductor Ld, the value of the equivalent capacitor Cd, and the value of the equivalent resistance Rd of the winding 11 to be tested by a simpler method. In other respects, it is the same as the test apparatus 1 according to the first embodiment.

As shown in FIG. 7, the test apparatus 1A has a parameter calculator 5A instead of the parameter calculator 5 according to the first embodiment.

The parameter calculation unit 5A determines that the initial value Vcd| _t=0 of the voltage Vcd in a predetermined period (analysis period Ta) determines the charge voltage Vcs (=E) of the impulse voltage application capacitor Cs as the impulse voltage application capacitor Cs and the equivalent capacitor Cd. Based on the equation showing the relationship between the impulse voltage applying capacitor Cs and the equivalent capacitor Cd and the measured value information 81 stored in the storage unit 8, the equivalent capacitor Calculate the value of Cd.

FIG. 8 is a diagram showing an example of an equivalent circuit based on the impulse voltage generation circuit 2 and the winding 11 when the switch SW is turned on in the test apparatus 1A according to the second embodiment.

In the equivalent circuit 21 shown in FIG. 8, the current limiting resistance Rs is set to zero (Rs=0), and the ON resistance of the switch SW and the ON resistance of the backflow prevention diode D are ignored.

In the second embodiment, when the switch SW is turned on, that is, at time t=0, as shown in FIG. Assume that it is represented by an equivalent circuit 21 connected in parallel with the external terminals T1 and T2 interposed therebetween.

It is also assumed that the value of the voltage Vcd at time t=0 is the initial value Vcd| _t= 0 of the voltage Vcd, and that the voltage Vcd reaches the maximum value Vmax at time t=0. Then, it is assumed that the initial value Vcd| _t=0 (=Vmax) of the voltage Vcd coincides with the voltage obtained by dividing the charging voltage Vcs of the impulse voltage applying capacitor Cs by the impulse voltage applying capacitor Cs and the equivalent capacitor Cd. .

Based on the above assumptions, the following equation (18) holds in the equivalent circuit 21 . Here, the initial value Vcs| _t=0 of the voltage Vcs of the impulse voltage applying capacitor Cs is assumed to be the charging voltage E (Vcs| _t=0 =E).

The parameter calculator 5A calculates the initial value Vcd| _t=0 of the voltage Vcd based on the measurement value information 81 in the above equation (19), the value of the impulse voltage applying capacitor Cs, and the initial value Vcs| _t of the voltage Vcs. ₌₀ (=E) to calculate the value of the equivalent capacitor Cd.

Note that the value (Vmax) of the initial value Vcd| _t=0 of the voltage Vcd based on the measured value information 81 is, for example, the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd of the winding 11 after the switch SW is turned on. may be the voltage (actually measured value) at the maximum point Pmax of the time-series data of the voltage Vcd in the period until the resonance starts based on the voltage Vcd, or the time-series data of the voltage Vcd is subjected to smoothing processing (for example, moving It may be the voltage at the maximum point of the smoothed waveform after performing smoothing processing using an averaging window.

Next, the parameter calculation unit 5A determines that the impulse voltage generation circuit 2 and the winding 11 after the switch SW is turned on (t>0) are equivalent inductor Ld, equivalent resistance Rd, impulse voltage application capacitor Cs, and current limiter. Suppose it is represented by an equivalent circuit 22 constituted by a resistor Rs.

FIG. 9 is a diagram showing an example of an equivalent circuit 22 based on the impulse voltage generation circuit 2 and the winding 11 after the switch SW is turned on (t>0) in the test apparatus 1A according to the second embodiment.

In FIG. 9, illustration of the switch SW and the backflow prevention diode D is omitted.

When the on-resistance of the switch SW, the on-resistance of the anti-backflow diode D, and the forward voltage drop are ignored, the impulse in the period in which the forward current flows through the anti-backflow diode D after the switch SW is turned on (t>0) The voltage generating circuit 2 is equivalently represented by a current limiting resistor Rs and an impulse voltage applying capacitor Cs connected in series between the external terminals T1 and T2, as shown in FIG. After the switch SW is turned on (t>0), the circuit on the winding 11 side is equivalently represented by an equivalent resistance Rd and an equivalent inductor Ld connected in series between the external terminals T1 and T2. be done.

Therefore, in the second embodiment, the equivalent circuit 22 after turning on the switch SW (t>0) is a circuit obtained by removing the equivalent capacitor Cd from the equivalent circuit 20 (see FIG. 4) in the first embodiment.

In the equivalent circuit 22, the equation representing the temporal change (transient response) of the voltage Vcd between the external terminals T1 and T2 after the switch SW is turned on is expressed by the following equation (20).

The parameter calculation unit 5A performs regression analysis using the measured value of the voltage Vcd in a predetermined period (analysis period Ta) to obtain the coefficient is calculated, and the value of the equivalent inductor Ld and the value of the equivalent resistance Rd are calculated based on the calculated coefficient and the initial value Vcd| _t=0 of the voltage Vcd.

For example, the parameter calculation unit 5A uses the time-series data of the voltage Vcd in the analysis period Ta stored in the storage unit 8 as the measured value information 81 by a known regression analysis method (for example, the least squares method) using the normal equation is created, and the coefficients of the respective terms of the above equation (20) are obtained by performing calculations such as the inverse matrix and the LU decomposition method. Next, the parameter calculator 5A calculates values of the equivalent inductor Ld and the equivalent resistance Rd based on the calculated coefficients and the values of Cs and Rs stored in advance in the storage unit 8 .

Since the above equation (20) includes a second-order differential value, noise included in the measurement result of the voltage Vcd is likely to be emphasized. That is, the second-order differential value is strongly affected by local waveform changes such as ringing due to parasitic capacitance and parasitic inductance that do not appear in the equivalent circuit 22, so the estimated values of the constants obtained by the least-squares method can easily fluctuate. have a nature.

Therefore, in order to further improve the calculation accuracy of the equivalent inductor Ld and the equivalent resistance Rd, the parameter calculation unit 5A performs regression analysis based on the integration of the above equation (20), and calculates the equivalent inductor Ld and the equivalent resistance Rd. may be calculated.

For example, the parameter calculation unit 15A calculates the equivalent inductor Ld and the equivalent resistance Each value of Rd may be determined.

By transforming the above formula (21), it can be represented by the following formula (22).

The parameter calculation unit 5A uses the time-series data of the voltage Vcd in the analysis period Ta stored in the storage unit 8 as the measurement value information 81 by a known regression analysis method (for example, the least squares method), using a normal equation (for example , simultaneous linear equations) are created, and the coefficients of the equation (22) are calculated by performing calculations such as inverse matrix and LU decomposition method. Next, the parameter calculator 5 calculates values of the equivalent inductor Ld and the equivalent resistance Rd based on the calculated coefficients and the values of Cs and Rs stored in advance in the storage unit 8 .

The parameter calculation unit 5A stores the respective values of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd calculated by the method described above in the storage unit 8 as the analysis result information 83A.

As in the first embodiment, the information necessary for the above calculation by the parameter calculator 5A may be stored in the storage 8 in advance. For example, an arithmetic expression for calculating the coefficients of the above formula (20), the above formula (21), or the above formula (22) from the measured value of the voltage Vcd, the value of the current limiting resistor Rs, and the impulse voltage application capacitor Cs and the like may be stored in the storage unit 8 in advance as the mathematical expression information 82A.
As a result, the parameter calculator 5A uses the measured value information 81, the formula information 82, and the value of the impulse voltage E set at the start of the test, which are stored in the storage unit 8, to calculate the equivalent capacitor The values of Cd, equivalent inductor Ld, and equivalent resistance Rd can be calculated.

In the test apparatus 1A according to the second embodiment, similarly to the test apparatus 1 according to the first embodiment, the waveform generator 6 generates time-series data (measured value Based on the information 81), a measured waveform 300 representing the temporal change of the voltage Vcd is generated and stored in the storage unit 8 as measured waveform data 84. FIG. Further, the waveform generator 6 calculates the transient response equation (formula (20) ) to generate a theoretical waveform 310 representing the temporal change of the voltage Vcd in the equivalent circuit 22 and store it in the storage unit 8 as theoretical waveform data 85 .

The display unit 7 displays the measured waveform 300 and the theoretical waveform 310 of the voltage Vcd based on the measured waveform data 84 and the theoretical waveform data 85 stored in the storage unit 8, similarly to the test apparatus 1 according to the first embodiment. It is displayed on the display 70 screen.

Next, the flow of the method for analyzing the winding 11 to be tested using the test apparatus 1A according to the second embodiment will be described.

FIG. 10 is a flow chart showing the flow of the method for analyzing the windings 11 using the testing apparatus 1A according to the second embodiment.

In the flowchart shown in FIG. 10, the processes from step S1 to step S6 are the same as those in the flowchart (FIG. 6) according to the first embodiment.

After step S6, the parameter calculation unit 5A stores the initial value _Vcd | Using the stored mathematical expression information 82A, the equivalent capacitor Cd relating to the winding 11 is calculated (step S7A).

Next, the parameter calculation unit 5A calculates the time-series data of the measured value of the voltage Vcd after the time t=0 in the analysis period Ta set in step S6 and the mathematical expression information 82A stored in the storage unit 8 by the method described above. are used to calculate the equivalent inductor Ld and the equivalent resistance Rd of the winding 11 (step S8A).

Next, the waveform generator 6 generates the measured waveform data 84 based on the measured value of the voltage Vcd acquired in step S5 by the method described above, and also generates the measured waveform data 84 related to the winding 11 calculated in steps S7A and S8A. The theoretical waveform data 85 is generated using the values of the equivalent capacitor Cd, equivalent inductor Ld, and equivalent resistance Rd (step S9A).

Next, the display unit 7 superimposes, for example, the measured waveform 300 and the theoretical waveform 310 on the screen of the display 70 of the test apparatus 1 based on the measured waveform data 84 and the theoretical waveform data 85 generated in step S9A. display (step S10A).

As in the test apparatus 1 according to the first embodiment, the above-described waveform data generation processing (step S9A) and waveform display processing (step S10A) are performed by the instruction input unit 3, for example, when the user requests waveform display. It may be executed only when an instruction is received.

As described above, in the test apparatus 1 according to the embodiment, the parameter calculation unit 5A determines that the initial value _Vcd | An equation (formula (19) above) showing the relationship between the impulse voltage applying capacitor Cs and the equivalent capacitor Cd, assuming that they match the voltage divided by the applying capacitor Cs and the equivalent capacitor Cd, and the storage unit 8 The value of the equivalent capacitor Cd is calculated based on the measured value information 81 stored in .
According to this, it is possible to calculate the equivalent capacitor Cd, which is one of the parameters related to the winding 11 to be tested, without performing complicated calculations. Further, even if the value of Vcd| _t=0 is calculated deviating from the optimum value due to ringing of the waveform, etc., the value of Vcd| _t=0 will be Even if the calculated values deviate from the optimum values, the calculated values of constant Ld and constant Rd are unlikely to be inappropriate values.

Further, the parameter calculation unit 5A performs regression analysis using the measured value of the voltage Vcd in a predetermined period (analysis period Ta) to determine the equivalent inductor Lc and equivalent resistance Rd, the impulse voltage application capacitor Cs and the current limiting resistor Rs and the coefficient of the equation of the transient response of the voltage Vcd in the equivalent circuit 22 (for example, the above equation (20) or (22)) are calculated, and the calculated coefficient and the initial voltage value Vcd| _t=0 and , the value of the equivalent inductor Ld and the value of the equivalent resistance Rd are calculated.

According to this, since a simpler equivalent circuit is used than in the prior art, the unknown (equivalent capacitor Cd) can be reduced by one and the order of the transient response equation (differential equation) in the regression analysis can be lowered. can. This makes it difficult to calculate inappropriate values for the equivalent inductor Ld and the equivalent resistance Rd even when magnetic saturation occurs or when the configuration of the coil to be tested is complicated.

Further, as described above, the parameter calculator 5A may perform regression analysis based on the equation (equation (21) or (22)) obtained by integrating equation (20). According to this, it is possible to remove the term of the second derivative included in the above equation (20), so that the influence of noise corresponding to the second derivative value included in the measured value of the voltage Vcd can be suppressed. It is possible. Regarding the term of the first derivative, for example, by performing the smoothing process described above on the measurement result (time-series data) of the voltage Vcd, the influence of noise corresponding to the first derivative contained in the voltage Vcd can be suppressed. In this way, by performing regression analysis based on the integration of the above equation (20), it becomes possible to calculate the equivalent inductor Ld and the equivalent resistance Rd with higher accuracy.

In the second embodiment, the transient response equation used in the regression analysis may be an equation obtained by integrating a differential equation representing temporal changes in the voltage Vcd of the equivalent circuit 22 with respect to time. 20) is not limited to the above equations (21) and (22) obtained by performing definite integration once from time t=0 to time t=a with respect to time t. For example, the parameter calculation unit 5A performs regression analysis based on the equation obtained by performing definite integration twice on the above equation (20) from time t=0 to time t=a for time t, thereby obtaining the equivalent inductor Ld and the equivalent A resistance Rd may be calculated.

Moreover, the test apparatus 1A according to the second embodiment displays the measured waveform 300 and the theoretical waveform 310 of the voltage Vcd on the screen of the display 70 based on the measured waveform data 84 and the theoretical waveform data 85, as described above.
According to this, the user can easily compare the measured waveform and the theoretical waveform, so that it becomes easy to judge whether or not the obtained analysis result (parameter) is an appropriate value.

<<Embodiment 3>>
FIG. 11 is a diagram showing the configuration of a test apparatus 1B according to Embodiment 3. As shown in FIG.

The test apparatus 1B according to the third embodiment changes the initial value Vcd| _t=0 of the voltage Vcd, calculates a plurality of data pairs of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd, and The test apparatus according to the second embodiment is characterized in that the error between the theoretical waveform and the measured waveform based on the data pair is calculated, and the data pair corresponding to the theoretical waveform with the smallest error is used as the analysis result of the winding 11 to be tested. Unlike 1A, it is the same as test apparatus 1A in other respects.

As shown in FIG. 11, the test apparatus 1B has a parameter calculator 5B instead of the parameter calculator 5A according to the second embodiment, and further has an error calculator 9. FIG.

The parameter calculator 5B has a function of calculating a plurality of data pairs including the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd, in addition to the function of the parameter calculator 5A according to the second embodiment.

Specifically, the parameter calculation unit 5B changes the initial value Vcd|t= ₀ of the voltage Vcd to a plurality of mutually different values, and changes the value of the equivalent capacitor Cd for each changed initial value Vcd| _t=0 of the voltage Vcd. , the value of the equivalent inductor Ld, and the value of the equivalent resistance Rd. For example, the parameter calculator 5B sets an initial value Vcd| _t=0 of n different voltages Vcd (where n is an integer equal to or greater than 2), and includes an equivalent capacitor Cd, an equivalent inductor Ld, and an equivalent resistance Rd. Calculate n sets of data pairs.

When the value (initial value) Vcd| _t=0 of the voltage Vcd at time t=0 when the switch SW is turned on is set to "Vmax", the parameter calculator 5B, for example, sets Vmax to a predetermined ratio (hereinafter referred to as "correction The value of the voltage Vcd (initial value) Vcd| _t=0 is set to a plurality of different values by increasing or decreasing the voltage Vcd by a factor.

Here, "Vmax" may be, for example, the measured value of the voltage Vcd at time t=0, or the maximum value of the smoothed waveform obtained by smoothing the measured value of the voltage Vcd. Also, the correction factor is

For example, when n=5, the parameter calculator 5A may set five initial values Vcd| _t=0 by changing Vcd| _t=0 from −20% to +20% in increments of 10%. . That is, the parameter calculator 5A calculates "Vmax×(1.00-0.20)", "Vmax×(1.00-0.10)", "Vmax×1.00", "Vmax×(1.00-0.10)". 00+0.10)” and “Vmax×(1.00+0.20)”, five initial values Vcd| _t=0 may be set.

Note that the initial value Vcd| _t=0 may be set to any value different from each other, and is not necessarily limited to the above example. For example, it is not necessary to change the correction rate at regular intervals (every 10%). Also, the number of initial values Vcd| _t=0 to be set is not limited to "5". Also, the correction rate of Vmax is not limited to -20% to +20%.

The parameter calculation unit _5B calculates the equivalent capacitor The value of Cd, the value of the equivalent inductor Ld, and the value of the equivalent resistance Rd are calculated, and n sets of analysis result information (data pairs) 83B_1 to 83B_n are stored in the storage unit 8. FIG.

In the case of the above example, the parameter calculator 5B calculates data pairs including the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd for five (n=5) Vcd| _t=0 , and They are stored in the storage unit 8 as analysis result information 83B_1 to 83B_5.

In the following description, when the constituent elements with suffixes attached to the reference numerals of the analysis result information 83B_1 to 83B_n are not distinguished from each other, the reference numerals without the suffixes such as "analysis result information 83B" shall be represented by

The waveform generator 6 generates a theoretical waveform of the voltage Vcd for each initial value Vcd| _t=0 of the voltage Vcd. That is, the waveform generation unit 6 generates theoretical waveforms for each of the analysis result information 83B_1 to 83B_n by the same method as in the first and second embodiments, and stores them in the storage unit 8 as theoretical waveform data 85B_1 to 85B_n. In the above example, the waveform generator 6 generates theoretical waveform data 85B_1 to 85B_5 for each piece of analysis result information 83B_1 to 83B_5.

The error calculator 9 calculates the error between the theoretical waveform of the voltage Vcd generated by the waveform generator 6 and the measured waveform of the voltage Vcd measured by the voltage measurer 4 . The error calculator 9 calculates the error for each Vcd| _t=0 of the voltage Vcd.

For example, the error calculator 9 calculates an error (for example, a squared error) between the theoretical waveform data 85B_1 and the measured waveform data 84 for each unit time during the analysis period Ta, and stores the calculated integrated value of the errors as the error data 86_1. Store in part 8. Similarly, the error calculator 9 calculates the error between the theoretical waveform data 85B_n and the measured waveform data 84 for each unit time, and stores the calculated integrated value of the errors in the storage unit 8 as the error data 86_n.

The parameter calculator 5B uses the value of the equivalent capacitor Cd, the value of the equivalent inductor Ld, and the value of the equivalent resistance Rd that minimize the error as the analysis result of the winding 11 to be tested. For example, the parameter calculation unit 5B calculates a data pair (analysis result information _{83B_1} 83B_n), the data pair with the smallest error is taken as the analysis result of the winding 11 to be tested. A detailed description will be given below with reference to FIGS. 12 to 15. FIG.

FIG. 12 is a diagram showing an example of the error between the theoretical waveform and the measured waveform of the voltage Vcd when the initial value Vcd| _t=0 of the voltage Vcd is changed.

FIG. 13 is a diagram showing an example of the equivalent inductor Ld when the initial value Vcd| _t=0 of the voltage Vcd is changed.

FIG. 14 is a diagram showing an example of the equivalent capacitor Cd when the initial value Vcd| _t=0 of the voltage Vcd is changed.

FIG. 15 is a diagram showing an example of the equivalent resistance Rd when the initial value Vcd| _t=0 of the voltage Vcd is changed.

12 to 15, the horizontal axis represents the correction rate [%] of the initial value Vcd| _t=0 of the voltage Vcd. In FIG. 12, the vertical axis represents the total value (integrated value) in the analysis period Ta of the square error between the theoretical waveform and the measured waveform of the voltage Vcd for each unit time. In FIG. 13, the vertical axis represents the equivalent inductor Ld, in FIG. 14 the vertical axis represents the equivalent capacitor Cd, and in FIG. 15 the vertical axis represents the equivalent resistance Rd.

12, the reference value of the initial value Vcd| _t=0 of the voltage Vcd is set to “Vmax”, and the reference value is corrected (changed) by a predetermined correction rate (−50% to +80%). It represents the change in the error (sum of squared errors) when A graph indicated by reference numeral 202 in FIG. 13 represents changes in the equivalent inductor Ld when the reference value is corrected (changed) by a predetermined correction rate (-50% to +80%). A graph indicated by reference numeral 203 in FIG. 14 represents changes in the equivalent capacitor Cd when the reference value is corrected (changed) by a predetermined correction rate (-50% to +80%). A graph indicated by reference numeral 204 in FIG. 15 represents changes in the equivalent resistance Rd when the reference value is corrected (changed) by a predetermined correction rate (-50% to +80%).

From the graph indicated by reference numeral 201 in FIG. 12, it can be understood that the error is minimized at the initial value Vcd| _t=0 of the voltage Vcd when the correction rate is about "-3.3%".

Therefore, when the point where the error is minimum (minimum error point) is "Q", the parameter calculator 5B calculates the value of the equivalent capacitor Cd, the value of the equivalent inductor Ld, and the value of the equivalent resistance Rd at the minimum error point Q. The data pair (analysis result information 83B) containing is the analysis result of the winding 11 to be tested.

In the case of the above example, the parameter calculation unit 5B calculates the analysis result information 83B including the value Ld_q of the equivalent inductor Ld in FIG. 13, the value Cd_q of the equivalent capacitor Cd in FIG. 14, and the value Rd_q of the equivalent resistance Rd in FIG. is the analysis result of the winding 11 to be tested. In this manner, the analysis result information 83 selected by the parameter calculation unit 5B is displayed on the display 70 of the display unit 7 as, for example, information on the analysis result of the winding 11 to be tested.

The display unit 7 may display at least one of the graphs (201 to 204) shown in FIGS. 13 to 15 on the display 70. FIG.

Next, a flow of a method for analyzing the winding 11 to be tested using the test apparatus 1B according to the third embodiment will be described.

FIG. 16 is a flow chart showing the flow of the method for analyzing the winding 11 using the testing apparatus 1B according to the third embodiment.

In the flowchart shown in FIG. 16, the processes from step S1 to step S9A are the same as those in the flowchart (FIG. 10) according to the second embodiment.

After step S9A, the error calculator 9 calculates the theoretical waveform data 85 and the measured waveform data 84 when the initial value Vcd| _t=0 of the voltage Vcd generated in step S9A is "Vmax" by the method described above. , and stored in the storage unit 8 as error data 86 (step S10B).

Next, the parameter calculator 5 changes the correction factor for the initial value Vcd| _t=0 of the voltage Vcd, calculates the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd, and calculates the error between the measured waveform and the theoretical waveform. (steps S8A to S10B) has been performed a predetermined number of times (step S11B). Here, the predetermined number of times, that is, the number of times the correction factor is changed may be set in advance in the storage unit 8, or may be set by the user operating the test apparatus 1B before executing the analysis of the winding 11. You may

If the above process (steps S8A to S10B) has not been performed a predetermined number of times (step S11B: NO), the parameter calculator 5 calculates the initial value Vcd| _{t= 0} is changed (step S12B). Next, parameter calculator 5B, waveform generator 6, and error calculator 9 execute steps S8A to S10B using the initial value Vcd| _t=0 of voltage Vcd changed in step S12B.

When the above process (steps _S8A to S10B) has been performed a predetermined number of times (step S11B: YES), the parameter calculator 5 changes the initial value Vcd| Among the plurality of analysis result information 83B_1 to 83B_n including the equivalent capacitor Cd, equivalent inductor Ld, and equivalent resistance Rd, the analysis result information 83 with the smallest error is selected as the analysis result of the winding 11 to be tested (step S13B).

Next, the display unit 7 displays information about the analysis result information 83 selected by the parameter calculation unit 5 in step S13 (step S14B). For example, the display unit 7 displays the respective values of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd included in the analysis result information 83 selected by the parameter calculation unit 5 in step S13 on the screen of the display 70. good too.

Further, for example, the display unit 7 displays the theoretical waveform and the measured waveform based on the analysis result information 83 selected by the parameter calculation unit 5 in step S13 in the same manner as the test apparatus 1 according to the first embodiment. You may Further, the display unit 7 may display at least one of the graphs indicated by reference numerals 201 to 204 in FIGS. 12 to 15 on the display 70. FIG.

The information displayed by the display unit 7 in step S14B may be information designated by the user through the instruction input unit 3, as in the test apparatus 1 according to the first embodiment.

As described above, in the test apparatus 1B according to the third embodiment, the parameter calculation unit 5B changes the initial value Vcd| _t=0 of the voltage Vcd to a plurality of mutually different values, and calculates the changed initial value Vcd| _t= For each ₀ , the value of the equivalent capacitor Cd, the value of the equivalent inductor Ld, and the value of the equivalent resistance Rd are calculated. The error calculator 9 calculates the error between the theoretical waveform of the voltage Vcd and the measured waveform of the voltage Vcd for each changed initial value Vcd| _t=0 of the voltage Vcd. The parameter calculation unit 5B calculates data pairs (analysis result information _{83B_1} to 83B_n ), the data pair with the smallest error is taken as the analysis result of the winding 11 to be tested.

According to this, even when the parameter (data pair) related to the winding 11 to be tested is calculated by a simpler regression analysis than in the prior art, the data that becomes the theoretical waveform closest to the measured waveform of the voltage Vcd Since the pairs are searched, the winding 11 can be analyzed with higher accuracy.

Also, the method of calculating the analysis result is not limited to the above example. For example, in the error data 86_1 to 86_n, approximate quadratic curves are obtained by plotting the correction rate on the horizontal axis and the error and Cd, Ld, and Rd on the vertical axis. Next, the correction factor that minimizes the error value on the approximate quadratic curve of the error is obtained. Then, the correction rate that minimizes the error value may be substituted into the approximate quadratic curves of Cd, Ld, and Rd, and the values of Cd, Ld, and Rd obtained thereby may be used as the analysis results. Alternatively, a known recursive algorithm may be used to obtain an approximation of the correction rate that minimizes the error value, and the analysis result may be obtained from the approximation of the correction rate in the same manner as described above.

<<Expansion of Embodiment>>
The invention made by the inventor of the present application has been specifically described above based on the embodiment, but the invention is not limited to it, and it goes without saying that various modifications can be made without departing from the gist of the invention. .

For example, in the above-described embodiment, the test apparatus 1 includes the backflow prevention diode D, but the test apparatus 1 may not include the backflow prevention diode D.

In the second and third embodiments, the switch SW is turned on at time t=0 in the analysis period Ta, but the present invention is not limited to this. For example, when time-series data obtained by performing smoothing processing using a moving average window on the time-series data of the voltage Vcd measured by the voltage measurement unit 4 is used for regression analysis, the rising time of the smoothed waveform and the switch The time when the switch is turned on may be different. Also, the time when the smoothed waveform reaches its maximum value and the time when the switch SW is turned on may differ.

In such a case, for example, interpolation is performed from the rising time of the smoothed waveform to the time when the smoothed waveform reaches its maximum value so that the smoothed waveform is Vcd to which the correction factor is added at the time when the switch SW is turned on. can be calculated by

Also, the above-described flowchart is an example for explaining the operation, and is not limited to this. That is, the steps shown in each figure of the flowchart are specific examples, and the flow is not limited to this flow. For example, the order of some processes may be changed, other processes may be inserted between each process, and some processes may be performed in parallel.

DESCRIPTION OF SYMBOLS 1, 1A, 1B... Testing apparatus, 2... Impulse voltage generation circuit, 3... Instruction input part, 4... Voltage measurement part, 5, 5A, 5B... Parameter calculation part, 6... Waveform generation part, 7... Display part, 8 ... storage unit 9 ... error calculation unit 20 to 22 ... equivalent circuit 81 ... measurement value information 82 ... formula information 83, 83B_1 to 83B_n ... analysis result information 84 ... measurement waveform data 85, 85B_1 to 85B_n ... Theoretical waveform data 86_1 to 86_n... Error data Cs... Impulse voltage applying capacitor Cd... Equivalent capacitor on winding 11 side Ld... Equivalent inductor on winding 11 side Rd... Equivalent resistance on winding 11 side Rs Current limiting resistor D Rectifying element (backflow prevention diode) E Impulse voltage Ta Analysis period Pmax Maximum point Pmin Minimum point T1 External terminal (first external terminal) T2 External terminal (Second external terminal), 70...Display, 300...Measured waveform, 310...Theoretical waveform.

Claims (13)

a first external terminal to which one terminal of the winding to be tested is connected, and a second external terminal to which the other terminal of the winding is connected;
an impulse voltage applying capacitor having one end connected to the second external terminal;
a switch connected between the other end of the impulse voltage applying capacitor and the first external terminal;
a current limiting resistor connected in series with the switch between the other end of the impulse voltage applying capacitor and the first external terminal;
an instruction input unit that receives an instruction to start testing;
a voltage measuring unit that measures the voltage between the first external terminal and the second external terminal;
a storage unit that stores measured value information including the measured value of the voltage measured by the voltage measuring unit;
An equivalent inductor connected between the first external terminal and the second external terminal, an equivalent capacitor connected between the first external terminal and the second external terminal, and the first The value of the equivalent inductor, the value of the equivalent capacitor, and the value of the equivalent resistance when equivalently represented by the equivalent resistance connected in series with the equivalent inductor between the first external terminal and the second external terminal. a parameter calculation unit that calculates at least one of the values based on the measured value information stored in the storage unit;
The instruction input unit turns on the switch in response to the instruction to start the test,
The parameter calculation unit
Among the measured value information stored in the storage unit, a predetermined period from when the switch is turned on until resonance based on the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding starts calculating at least one of the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value by performing a regression analysis using the measured values of the voltage over a period of . In the testing device according to claim 1,
The switch and the current limiting resistor are connected in series between the other end of the impulse voltage applying capacitor and the first external terminal, and current passes from the impulse voltage applying capacitor side to the first external terminal side. and a rectifying element that cuts off current from the first external terminal side to the impulse voltage applying capacitor side. In the test device according to claim 1 or 2,
The parameter calculation unit detects a maximum point at which the voltage is maximum and a minimum point at which the voltage is minimum after the switch is turned on, and calculates a period between the maximum point and the minimum point as the predetermined period. A test device characterized by a period of In the test device according to any one of claims 1 to 3,
The parameter calculation unit performs regression analysis using the measured values of the voltage in the predetermined period to determine the equivalent inductor, the equivalent capacitor, and the equivalent resistance, the impulse voltage applying capacitor, and the current limiting resistor. and calculating the coefficients of the voltage transient response equation in the equivalent circuit composed of and calculating the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance based on the calculated coefficients testing equipment. In the test device according to claim 4,
A test apparatus according to claim 1, wherein the transient response equation is an equation obtained by integrating a differential equation expressing the temporal change of the voltage in the equivalent circuit multiple times with respect to time. In the test device according to claim 5,
The transient response equation is an equation obtained by integrating the differential equation three times over time,
Ld is the value of the equivalent inductor, Cd is the value of the equivalent capacitor, Rd is the value of the equivalent resistance, Cs is the value of the impulse voltage applying capacitor, Rs is the value of the current limiting resistor, and the first external terminal and A test apparatus according to claim 1, wherein the equation obtained by integrating three times is represented by the following equation (1), where Vcd is the voltage between the second external terminal and t is the time.

In the test device according to claim 5,
The transient response equation is an equation obtained by integrating the differential equation twice with respect to time,
Ld is the value of the equivalent inductor, Cd is the value of the equivalent capacitor, Rd is the value of the equivalent resistance, Cs is the value of the impulse voltage applying capacitor, Rs is the value of the current limiting resistor, and the first external terminal and A test apparatus according to claim 1, wherein the equation obtained by performing the integration twice is expressed by the following equation (2), where Vcd is the voltage between the second external terminal and t is the time.

In the test device according to any one of claims 4 to 7,
A theoretical waveform of the voltage is generated by performing numerical integration using the transient response equation to which the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value calculated by the parameter calculation unit are applied. a waveform generator that
The test apparatus further includes a display section for displaying the theoretical waveform generated by the waveform generation section and the measured waveform of the voltage measured by the voltage measurement section. In the test device according to claim 1 or 2,
The parameter calculation unit calculates the initial value of the voltage in the predetermined period when it is assumed that the voltage obtained by dividing the charged voltage of the impulse voltage applying capacitor by the impulse voltage applying capacitor and the equivalent capacitor. calculating the value of the equivalent capacitor based on the equation representing the relationship between the impulse voltage applying capacitor and the equivalent capacitor and the measured value information stored in the storage unit;
The parameter calculation unit is configured by the equivalent inductor, the equivalent resistance, the impulse voltage applying capacitor, and the current limiting resistor by performing regression analysis using the measured value of the voltage in the predetermined period. A test characterized by calculating the coefficients of the voltage transient response equation in an equivalent circuit, and calculating the equivalent inductor value and the equivalent resistance value based on the calculated coefficients and the initial value of the voltage. Device. In the test device according to claim 9,
A theoretical waveform of the voltage is generated by performing numerical integration using the transient response equation to which the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value calculated by the parameter calculation unit are applied. a waveform generator that
an error calculator that calculates an error between the theoretical waveform generated by the waveform generator and the measured waveform of the voltage measured by the voltage measurement unit;
The test apparatus, wherein the parameter calculation unit uses the value of the equivalent capacitor, the value of the equivalent inductor, and the value of the equivalent resistance that minimize the error as the analysis result of the winding. In the test device according to claim 9 or 10,
A test apparatus according to claim 1, wherein the transient response equation is an equation obtained by integrating a differential equation representing temporal changes in the voltage of the equivalent circuit with respect to time. The test device of claim 11, wherein
The value of the equivalent inductor is Ld, the value of the equivalent capacitor is Cd, the value of the equivalent resistance is Rd, the value of the impulse voltage applying capacitor is Cs, the value of the current limiting resistor is Rs, the first external terminal and the When the voltage between the second external terminal is Vcd and the time is t, the transient response equation is obtained by integrating the differential equation from time t=0 to time t=a (a>0). A test apparatus characterized by being represented by the following formula (3).

A first external terminal to which one terminal of a winding to be tested is connected, a second external terminal to which the other terminal of the winding is connected, and an impulse voltage application having one end connected to the second external terminal. a switch connected between the other end of the impulse voltage applying capacitor and the first external terminal; and the switch between the other end of the impulse voltage applying capacitor and the first external terminal. A test method using a test device comprising a current limiting resistor connected in series with
a first step of turning on the switch;
a second step of measuring the voltage between the first external terminal and the second external terminal;
a third step of storing measured value information including the measured value of the voltage measured in the second step;
An equivalent inductor connected between the first external terminal and the second external terminal, an equivalent capacitor connected between the first external terminal and the second external terminal, and the first The value of the equivalent inductor, the value of the equivalent capacitor, and the value of the equivalent resistance when equivalently represented by the equivalent resistance connected in series with the equivalent inductor between the first external terminal and the second external terminal. a fourth step of calculating at least one of the values based on the measured value information stored in the third step;
The fourth step is
Among the measured value information stored in the third step, a predetermined period from when the switch is turned on to when resonance based on the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding starts calculating at least one of the equivalent capacitor value, the equivalent inductor value, and the equivalent resistance value by performing a regression analysis using measurements of the voltage over time.

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