JP2023123087A - Test device, and test method - Google Patents

Abstract

To enable analyzing a change in characteristic of a winding of a test object even in the case that magnetic saturation has occurred.SOLUTION: A test device 1 has: an impulse voltage application-purpose capacitor Cs with one end connected to an external terminal T2; a switch SW and current limit resistor R that are connected in series between the other end of the impulse voltage application-purpose capacitor Cs and an external terminal T1; a measurement unit 4 that measures a voltage Vcd between the external terminal T1 and external terminal T2, and a voltage Vcs between both ends of the impulse voltage application-purpose capacitor; and a parameter calculation unit 5. The parameter calculation unit 5 is configured to calculate a time-variant change in at least one value of an equivalent inductor Ld, equivalent capacitor Cd and equivalent resistor Rd representing equivalently a winding 11 on the basis of measurement values of the voltage Vcd and voltage Vcs measured by the measurement unit 4.SELECTED DRAWING: Figure 1

Description

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

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 testing 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.

Further, generally, when magnetic saturation occurs in a winding to be tested, parameters such as the inductance of the winding change. However, the conventional impulse winding test apparatus cannot accurately calculate parameters related to windings when magnetic saturation occurs.

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 enable analysis of changes in the characteristics of a winding to be tested even when magnetic saturation occurs.

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 first external terminal and the first external terminal; an instruction input unit for turning on the switch in response to an instruction to start testing; a measuring unit for measuring a first voltage between the second external terminal and a second voltage across the impulse voltage applying capacitor; and a measuring unit connected between the first external terminal and the second external terminal. a capacitor connected between the first external terminal and the second external terminal; and a resistor connected in series with the equivalent inductor between the first external terminal and the second external terminal. The first voltage and the second voltage measured by the measurement unit are the temporal changes in the value of at least one of the equivalent inductor, the equivalent capacitor, and the equivalent resistance when the windings are equivalently represented. A parameter calculation unit that calculates based on the measured value of the voltage, and memorizes measured value information including the measured value of the first voltage and the measured value of the second voltage and the value of the equivalent capacitor, which are measured by the measuring unit. and a storage unit, wherein the parameter calculation unit calculates resonance based on the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding after the switch is turned on, which is stored in the storage unit. Using the measured value of the first voltage and the measured value of the second voltage for each unit time in a predetermined period until the start of and the value of the equivalent capacitor stored in the storage unit , the first voltage in an equivalent circuit composed of the equivalent inductor, equivalent capacitor, and equivalent resistance of the winding, the impulse voltage applying capacitor, and the current limiting resistor during the predetermined period The value of at least one of the equivalent inductor and the equivalent resistance for each unit time is calculated by performing regression analysis based on a transient response equation and a transient response equation of the second voltage.

According to the test apparatus according to the present invention, it is possible to analyze changes in the characteristics of the winding to be tested even when magnetic saturation occurs.

It is a figure which shows the structure of the testing apparatus which concerns on embodiment of this invention. It is a figure which shows an equivalent circuit when the coil|winding to be tested is connected to a testing apparatus. 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 while the winding is connected to the test apparatus; FIG. 4 is a diagram for explaining a method of calculating an equivalent capacitor Cd of a winding; It is a figure which shows an example of the analysis result of the equivalent capacitor Cd of winding by a testing apparatus. It is a figure which shows an example of the analysis result of the equivalent capacitor Cd of winding by a testing apparatus. It is a figure which shows an example of the analysis result of the equivalent capacitor Cd of winding by a testing apparatus. FIG. 5 is a diagram showing an example of analysis results of the equivalent inductor Ld and the equivalent resistance Rd of the winding by the testing device when magnetic saturation does not occur in the winding; FIG. 5 is a diagram showing an example of analysis results of the equivalent inductor Ld and the equivalent resistance Rd of the winding by the testing device when magnetic saturation does not occur in the winding; FIG. 5 is a diagram showing an example of analysis results of the equivalent inductor Ld and the equivalent resistance Rd of the winding by the testing device when magnetic saturation does not occur in the winding; FIG. 5 is a diagram showing an example of analysis results of an equivalent inductor Ld and an equivalent resistance Rd of a winding by a testing device when magnetic saturation occurs in the winding; FIG. 5 is a diagram showing an example of analysis results of an equivalent inductor Ld and an equivalent resistance Rd of a winding by a testing device when magnetic saturation occurs in the winding; FIG. 5 is a diagram showing an example of analysis results of an equivalent inductor Ld and an equivalent resistance Rd of a winding by a testing device when magnetic saturation occurs in the winding; FIG. 10 is a diagram showing an example of waveforms representing values of the equivalent inductor Ld and the equivalent resistance Rd of the winding calculated by the testing device in another form; FIG. 10 is a diagram showing an example of waveforms representing values of the equivalent inductor Ld and the equivalent resistance Rd of the winding calculated by the testing device in another format; It is a figure which shows an example of the display screen of a testing apparatus. It is a flowchart which shows the flow of the analysis method of the winding using a testing apparatus.

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) 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, and a second external terminal (T2) to which the other terminal is connected; an impulse voltage applying capacitor (Cs) whose one end is connected to the second external terminal; the other end of the impulse voltage applying capacitor and the first a switch (SW) connected between an external terminal and a current limiting resistor (Rs) connected in series with the switch between the other end of the impulse voltage applying capacitor and the first external terminal; an instruction input section (3) for turning on the switch in response to an instruction to start testing; a first voltage (Vcd) between the first external terminal and the second external terminal; A measuring unit (4) for measuring a second voltage (Vcs) across both ends, an equivalent inductor (Ld) connected between the first external terminal and the second external terminal, the first external terminal and the The winding by an equivalent capacitor (Cd) connected between the second external terminal and an equivalent resistance (Rd) connected in series with the equivalent inductor between the first external terminal and the second external terminal When the line is equivalently represented, the change in the value of at least one of the equivalent inductor, the equivalent capacitor, and the equivalent resistance over time is measured by the measuring unit between the first voltage and the second voltage. a parameter calculator (5) for calculating based on the measured values; measured value information including the measured value of the first voltage and the measured value of the second voltage, and the value of the equivalent capacitor, which are measured by the measuring unit; and a storage unit that stores the value of the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding after the switch is turned on, which is stored in the storage unit. The measured value of the first voltage (Vcd) and the measured value of the second voltage (Vcs) for each unit time in a predetermined period (Ta) until the resonance based on the voltage is started, and the measured value of the second voltage (Vcs) stored in the storage unit configured by the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding, the impulse voltage applying capacitor, and the current limiting resistor in the predetermined period By performing regression analysis based on the equation of the transient response of the first voltage and the equation of the transient response of the second voltage in the equivalent circuit, the value per unit time of at least one of the equivalent inductor and the equivalent resistance It is characterized by calculating.

[2] In the test apparatus described in [1] 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 first voltage is Vcd, the second voltage is Vcs, and the time is t, the transient response equation of the first voltage is expressed by Equation (9) described later, A transient response equation of the second voltage may be represented by Equation (10) described below.

[3] In the test apparatus described in [1] or [2] above, the parameter calculation unit determines whether the current flowing through the equivalent inductor is Based on the measured value of the first voltage and the measured value of the second voltage in the first period (Tb) that can be regarded as zero, the value of the equivalent capacitor may be calculated and stored in the storage unit. good.

[4] In the test apparatus described in [3] above, the parameter calculator calculates the unit time (h) represented by the measured value of the first voltage and the measured value of the second voltage. The value of the equivalent capacitor may be calculated based on a relational expression between the change amount (Qd) of the electric charge of the equivalent capacitor in the above and the change amount (Vd) of the first voltage in the unit time.

[5] In the test apparatus described in [4] above, the measured value of the second voltage at time a in the first period is Vcs|t=a, and the measured value of the first voltage at time a is Vcd| t=a, the measured value of the second voltage at time a+h, which is ahead of time a by the unit time h, is Vcs|t=a+h, and the measured value of the first voltage at time a+h is Vcd|t=a+h , where Rs is the value of the current-limiting resistor and Cd is the value of the equivalent capacitor, the parameter calculator calculates the value of the equivalent capacitor for each unit time based on the following equation (8): good.

[6] In the test apparatus according to any one of [3] to [5] above, the measurement unit samples the first voltage and the second voltage every unit time (h), and determines the parameter The calculator acquires sampling data including the measured value of the first voltage and the measured value of the second voltage sampled by the measuring unit, and calculates a set of the sampling data of two sampling points adjacent to each other. The value of the equivalent capacitor may be calculated for each data pair.

[7] In the test apparatus according to any one of [3] to [6] above, the first period (Tb) is the period immediately after the switch is turned on during the period in which the first voltage is rising. It may be a period other than the predetermined period (Tx1) and the predetermined period (Tx2) immediately before the first voltage reaches the maximum value of the first voltage.

[8] In the test apparatus described in [7] above, the measured value of the first voltage is α (0≦α<100)% of the maximum value of the first voltage during the first period (Tb). It may be a period from time to time when the measured value of the first voltage is β (α<β≦100)% of the maximum value of the first voltage.

[9] In the test apparatus according to any one of [1] to [8] above, the value of at least one of the equivalent capacitor, the equivalent inductor, and the equivalent resistance calculated by the parameter calculator is temporally It may further include a waveform generation section (6) that generates waveform data showing a change, and a display section (7) that displays a waveform based on the waveform data.

[10] In the test apparatus described in [9] above, the display section may display a waveform representing a temporal change in the reciprocal (1/Ld) of the equivalent inductor value.

[11] In the test apparatus described in [9] or [10] above, the display section indicates a temporal change in a value (Rd/Ld) obtained by dividing the equivalent resistance value by the equivalent inductor value. A waveform may be displayed.

[12] 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 and a current limiting resistor (Rs) connected in series with the switch between the other end of the impulse voltage applying capacitor and the first external terminal. It is a test method using (1). The test method includes a first step (S4) of turning on the switch, a first voltage (Vcd) between the first external terminal and the second external terminal, and a second voltage across the impulse voltage applying capacitor. 2 a second step (S5) of measuring a voltage (Vcs), an equivalent inductor (Ld) connected between the first external terminal and the second external terminal, the first external terminal and the second external terminal, and an equivalent resistance (Rd) connected in series with the equivalent inductor between the first external terminal and the second external terminal. the measured value of the first voltage measured in the second step and the second voltage and a third step (S7, S8) of calculating based on the measured values of and the equivalent inductor, the equivalent capacitor, and the equivalent The measured value of the first voltage and the measured value of the second voltage for each unit time in a predetermined period until the resistance-based resonance starts, and the value of the equivalent capacitor stored in the test device. in the equivalent circuit composed of the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding, the impulse voltage applying capacitor, and the current limiting resistor during the predetermined period. The value per unit time of at least one of the equivalent inductor and the equivalent resistance is calculated by performing regression analysis based on the transient response equation of the first voltage and the transient response equation of the second voltage. and

2. Specific Examples of Embodiments Specific examples of embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a test apparatus 1 according to an embodiment of the invention.
A test apparatus 1 shown in FIG. 1 is, for example, an apparatus for measuring the characteristics of windings (coils) that constitute rotating machines such as electric motors and generators, and electrical equipment such as transformers. For example, the test apparatus 1 calculates each value of an inductor, a capacitor, and a 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 a winding test device.

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 measurement section 4, a parameter calculation section 5, a waveform generation section 6, a display section 7, and a storage section. 8.

The external terminals T1 and T2 are terminals for connecting windings 11 as a test object (DUT: Device Under Test). 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 generating circuit 2 has an impulse voltage applying capacitor Cs, a switch SW, a current limiting resistor Rs, and a rectifying element D, for example.

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 "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 the impulse voltage E between one end of the current limiting resistor Rs and the external terminal T2 via the switch SW in accordance with the instruction from the instruction input section 3 .
For example, first, the impulse voltage generation circuit 2 charges the impulse voltage application capacitor Cs by a DC power supply (not shown) so that the voltage of the impulse voltage application capacitor Cs becomes the impulse voltage E. FIG. Next, the impulse voltage generation circuit 2 turns on the switch SW 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 the sampling frequency of the measuring unit 4, which will be described later, the instruction input unit 3 stores these input values in the storage unit 8 so that the test apparatus 1 Set the test conditions to 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 measuring unit 4 is a functional unit that measures a physical quantity such as voltage when voltage is applied to the winding 11 connected between the external terminal T1 and the external terminal T2. Specifically, the measurement unit 4 measures the voltage Vcd (first voltage) between the external terminals T1 and T2 and the voltage Vcs (second voltage) across the impulse voltage applying capacitor Cs. For example, the measurement unit 4 measures the voltage between the node where the switch SW and the current limiting resistor Rs are connected and the external terminal T2 as the voltage Vcs.

For example, the measurement unit 4 samples the voltage and current detected by a known voltage detection circuit, current detection circuit, voltage detection circuit and current detection circuit at a predetermined sampling period, and converts them into digital signals through A/D conversion. circuit.

Measurement unit 4 stores measurement value information 81 including the measurement value of voltage Vcd and the measurement value of voltage Vcs in storage unit 8 . For example, the measurement unit 4 samples the voltage Vcd and the voltage Vcs at a predetermined sampling period to obtain time-series data of the measured values (sampling data) of the voltage Vcd and the voltage Vcs, and stores the data as the measured value information 81 in the storage unit. Store in 8.

Note that the method of measuring the voltage Vcs by the measuring unit 4 is not limited to the method of directly measuring the voltage between the node to which the switch SW and the current limiting resistor Rs are connected and the external terminal T2 using the voltage detection circuit. For example, the measuring unit 4 detects the current Irs flowing through the external terminal T1, that is, the current Irs flowing through the current limiting resistor Rs by means of a current detection circuit, and measures the voltage Vcs based on the measured values of the current Irs and the voltage Vcd. A value may be calculated (Vcs=Vcd+Rs*Irs). Alternatively, the measurement unit 4 may measure the voltage Vrs across the current limiting resistor Rs with a voltage detection circuit, and calculate the measured value of the voltage Vcs based on the measured values of the voltage Vrs and the voltage Vcd. Good (Vcs=Vcd+Vrs).

The parameter calculator 5 is a functional unit that calculates the values of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd as parameters related to 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.

Here, the parameter calculation unit 5, the waveform generation unit 6, and the storage unit 8 are implemented by, for example, a program processing device. The program processing device includes, for example, 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, and an input/output I/F. It is a microcontroller having a configuration in which peripheral circuits such as circuits are connected to each other via a bus or a dedicated line. For example, in a program processing device, a CPU executes various arithmetic processes according to a program stored in a memory, stores the arithmetic results in a storage device such as a RAM, and controls peripheral circuits such as counters and input/output interface circuits. By doing so, the above-described parameter calculator 5, waveform generator 6, and storage unit 8 are realized.

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 described above, the test apparatus 1 calculates parameters related to the winding 11 as analysis of the characteristics of the winding 11 to be tested. Specifically, the test apparatus 1 detects 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, and the impulse voltage application capacitor Cs. Values of equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd, which are parameters related to winding 11, are calculated based on the transient response characteristics of voltage Vcs across both ends.

FIG. 2 is a diagram showing an equivalent circuit when the winding 11 to be tested is connected to the testing apparatus 1. As shown in FIG.
FIG. 3 is a diagram showing 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. As shown in FIG.

In FIG. 3, the horizontal axis represents time [μs] and the vertical axis represents voltage [V]. A waveform indicated by reference numeral 110 indicates a temporal change in the voltage Vcd after the impulse voltage application capacitor Cs is charged so that the impulse voltage E becomes 1000 V and the switch SW is turned on.

As shown in FIG. 2, winding 11 is equivalently represented by equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd. Specifically, when the winding 11 side is viewed from the external terminals T1 and T2, the circuit includes an equivalent inductor Ld connected between the external terminals T1 and T2, and the external terminals T1 and 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 capacitor of the winding 11 Cd is charged.

When the switch SW is turned on at time t=0 s, the current does not flow through the equivalent inductor Ld of the winding 11 but into the equivalent capacitor Cd immediately after the switch SW is turned on due to the properties of the equivalent inductor Ld. 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, the resonance of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd of the winding 11 starts around time t=10 μs in FIG. 3, and the voltage Vcd undergoes damped oscillation. 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 shown in FIG. 3, in the test apparatus 1 according to the first embodiment, from when the switch SW is turned on until resonance by the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd on the winding side starts. With a predetermined period Ta as the analysis period, the equivalent inductor Ld, equivalent A temporal change in the value of at least one of the capacitor Cd and the equivalent resistance Rd is calculated.

Since the conventional impulse winding tester (measuring device) uses the equation and measured value of the voltage Vcd at resonance due to the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd of the winding 11, the LC value, RC value, etc. can only be calculated by multiplying each parameter of . On the other hand, the test apparatus 1 according to the present embodiment performs calculations based on the transient response equations of the voltages Vcd and Vcs in the equivalent circuit before resonance begins. Thereby, as will be described later, it is possible to individually calculate temporal changes in the values of the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd, and to complete the analysis in a shorter time. It becomes possible.
A specific method of calculating each parameter related to the winding 11 by the test apparatus 1 will be described below.

(1) Method for Calculating Equivalent Capacitor Cd First, a method for calculating the equivalent capacitor Cd of the winding 11 will be described.
The test apparatus 1 according to the present embodiment measures the unit The value of the equivalent capacitor Cd for each time is calculated and stored in the storage unit 8 as analysis result information 83 .

FIG. 4 is a diagram for explaining a method of calculating the equivalent capacitor Cd of the winding 11. As shown in FIG.
In FIG. 4, the waveform with reference numeral 110A is an enlarged portion of the range A of the waveform 110 of the voltage Vcd shown in FIG.

As described above, when the switch SW is turned on while the impulse voltage applying capacitor Cs is charged, the voltage Vcd changes from 0 V to the maximum value Vmax immediately after the switch SW is turned on, as indicated by reference numeral 110A in FIG. (eg, 980V).

Here, Irs is the current flowing through the current limiting resistor Rs of the impulse voltage generating circuit 2 to the external terminal T1, Icd is the current flowing through the equivalent capacitor Cd of the winding 11, and Icd is the equivalent inductor through the equivalent resistance Rd of the winding 11. When the current flowing through Ld is Ild, Irs=Icd+Ild.

As described above, immediately after the switch SW is turned on, no current flows to the equivalent inductor Ld side of the winding 11, so Ild=0. Assuming that Ild=0, the current Icd flowing through the equivalent capacitor Cd can be considered equal to the current Irs flowing from the current limiting resistor Rs to the external terminal T1. Rd can be ignored.

Therefore, the parameter calculator 5 calculates the measured value of the voltage Vcd and the voltage The value of the equivalent capacitor Cd is calculated based on the measured value of Vcs.

Here, the analysis period Tb for the equivalent capacitor Cd is, as shown in FIG. It is preferable that the period excludes the predetermined period Tx2 immediately before reaching the maximum value Vmax of .

For example, in the analysis period Tb, from the time tα when the measured value of the voltage Vcd becomes α (0≦α<100)% of the maximum value Vmax of the voltage Vcd, the measured value of the voltage Vcd becomes β(α <β≦100)% until the time tβ. Here, for example, α=25% and β=75%.

The period Tx1 includes a period during which it is unclear whether or not the switch SW is turned on. This is a period in which there is a high possibility that waveform distortion will occur. During the period Tx2, the current gradually begins to flow through the equivalent inductor Ld of the winding 11, and the precondition of Ild=0 is no longer satisfied. is likely to occur.

Therefore, by setting the period Tb, excluding the periods Tx1 and Tx2, as the analysis period of the equivalent capacitor Cd, it is possible to reduce the influence of the above-described ringing and the like on the analysis result of the equivalent capacitor Cd.

A method for calculating the equivalent capacitor Cd will be described in detail below.
When the voltage Vcs at the time t=a in the analysis period Tb is Vcs|t=a and the voltage Vcd at the time t=a is Vcd|t=a, from Irs=Icd, the current Icd at the time t=a is given by the following: It is represented by Formula (1).

When the voltage Vcs at time t=a+h (h is a unit time) in the analysis period Tb is Vcs|t=a+h, and the voltage Vcd at time t=a+h is Vcd|t=a+h, Irs=Icd, time t= The current Icd at a+h is represented by the following equation (2).

Here, the unit time h is, for example, the time corresponding to the sampling period of the A/D conversion circuit that constitutes the measurement section 4 described above.

Here, the average value Iave of the current Icd in the period from time t=a to time t=a+h is represented by the following equation (3).

A charge change amount Qd due to the current flowing into the equivalent capacitor Cd of the winding 11 during the period from time t=a to time t=a+h is expressed by the following equation (4) using the average value Iave of the current Icd. .

Also, the amount of change Vd in the voltage across the equivalent capacitor Cd during the period from time t=a to time t=a+h is expressed by the following equation (5).

Also, the relationship between the voltage change amount Vd and the charge amount change amount Qd in the equivalent capacitor Cd is represented by the following equation (6).

By substituting equations (4) and (5) into equation (6), equation (7) below is obtained.

As can be understood from the above equations (6) and (7), the value of the equivalent capacitor Cd is expressed by the amount of change in the charge of the equivalent capacitor Cd and the amount of change in the voltage Vcd of the equivalent capacitor Cd per unit time h. be.

Here, by substituting the above equations (1) to (3) into the above equation (7) and solving for Cd, the equivalent capacitor Cd can be expressed by the following equation (8).

As can be understood from the above equation (8), the equivalent capacitor Cd can be represented by the voltages Vcd and Vcs at two sampling points (times) during the analysis period Tb and the current limiting resistor Rs.

Therefore, the parameter calculator 5 calculates the change amount Qd of the charge of the equivalent capacitor Cd and the change amount Vd of the voltage Vcd in the unit time h, which are represented by the measured value of the voltage Vcd and the measured value of the voltage Vcs in the unit time h. (Equation (8) above), the value of the equivalent capacitor Cd per unit time is calculated.

Specifically, the parameter calculator 5 calculates the measured value Vcs|t=a of the voltage Vcs and the measured value Vcd|t=a of the voltage Vcd at the time t=a of the analysis period Tb, and the time t=a+h of the analysis period Tb. By substituting the measured value Vcs|t=a+h of the voltage Vcs and the measured value Vcd|t=a+h of Vcd at the above equation (8) and the known value of the current limiting resistor Rs, the value of the equivalent capacitor Cd is Calculate the value.

The parameter calculator 5 calculates multiple values of the equivalent capacitor Cd using multiple sampling data of the voltages Vcd and Vcs during the analysis period Tb. Specifically, the parameter calculator 5 acquires sampling data including the measured value of the voltage Vcd and the measured value of the voltage Vcs sampled by the measuring unit 4, and generates a set of sampling data of two adjacent sampling points. The value of the equivalent capacitor Cd is calculated for each data pair.

For example, in the analysis period Tb from time tα to time tβ shown in FIG. 4, it is assumed that the measurement unit 4 samples the voltages Vcs and Vcd every unit time h to obtain 21 sets of sampled data. In this case, the parameter calculation unit 5 substitutes a total of 20 sets of data pairs, each set of sampling data of two sampling points adjacent to each other, into the above equation (8) to obtain 20 sets of equivalent capacitors Cd. Calculate the value.
According to this, it is possible to know the temporal change of the equivalent capacitor Cd in the analysis period Tb.

The parameter calculation unit 5 calculates the average value or the median value of the values of a plurality of (20 in the above example) equivalent capacitors Cd calculated for each data pair described above, thereby obtaining one value (fixed value) of the equivalent capacitor Cd. value) may be calculated. Here, the method of calculating the average value of the equivalent capacitor Cd is not particularly limited, and various methods such as arithmetic averaging and trimming averaging can be employed.

The parameter calculator 5 stores the time-series data of the equivalent capacitor Cd calculated by the above method, the average value of the equivalent capacitor Cd, and the like as the analysis result information 83 in the storage unit 8 .

5 to 7 are diagrams showing an example of analysis results of the equivalent capacitor Cd of the winding 11 by the test apparatus 1. FIG.

5 to 7 show a waveform 120 of a voltage Vcd, a current A waveform 121 of Icd and a waveform 122 of the equivalent capacitor Cd value are shown respectively.

After the switch SW is turned on at time t=0, the voltage Vcd of the equivalent capacitor Cd is, as shown in FIG. While increasing linearly, as shown in FIG. 6, the current Icd flowing through the equivalent capacitor Cd decreases while oscillating. At this time, as shown in FIG. 7, the value of the equivalent capacitor Cd in the analysis period Tb fluctuates but becomes a stable value compared to other periods.

(2) Method for Calculating Equivalent Inductor Ld and Equivalent Resistance Rd Next, a method for calculating the equivalent inductor Ld and the equivalent resistance Rd of the winding 11 will be described.

The parameter calculation unit 5 calculates a predetermined value stored in the storage unit 8 from when the switch SW is turned on until resonance based on the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd of the winding 11 starts. Using the measured values (measured value information 81) of the voltages Vcd and Vcs for each unit time in the period of and the value of the equivalent capacitor Cd (analysis result information 83) stored in the storage unit 8, the predetermined period , the equation of the transient response of the voltage Vcd based on an equivalent circuit composed of the equivalent inductor Ld of the winding 11, the equivalent capacitor Cd, the equivalent resistance Rd, the impulse voltage applying capacitor Cs, and the current limiting resistor Rs, and the voltage A value per unit time of at least one of the equivalent inductor Ld and the equivalent resistance Rd is calculated by performing regression analysis based on the Vcs transient response equation.

The parameter calculation unit 5 calculates the above-described predetermined period, that is, the analysis period of the equivalent inductor Ld and the equivalent resistance Rd, after the switch SW is turned on. is defined as an analysis period (see FIG. 3).

More preferably, the parameter calculator 5 analyzes the period from a predetermined time after the voltage Vcd reaches the maximum value Vmax after the switch SW is turned on to a predetermined time before the voltage Vcd reaches the minimum value. period. For example, as shown in FIG. 3, the period Tc from the time t1 when the voltage Vcd reaches 90% of its positive peak value to the time t2 when the voltage Vcd reaches 90% of its negative peak value is the equivalent inductor Ld and the equivalent This is the period for analysis of the resistance Rd.

By excluding the period up to time t1 from the analysis period, the period in which the voltage Vcd rises immediately after the switch SW is turned on is excluded. The influence of Rd on analysis results can be reduced. Similarly, by excluding the period from the time t2 to the time when the rectifying element D cuts off the current from the analysis period, the influence of the equivalent inductor Ld and the equivalent resistance Rd on the analysis results can be reduced.

The parameter calculator 5 uses the measured values of the voltages Vcd and Vcs during the analysis period Tc to perform regression analysis based on the equation of the transient response of the voltages Vcd and Vcs, thereby calculating the values of the equivalent inductor Ld and the equivalent resistance Rd over time. Calculate the change in A method for calculating the equivalent inductor Ld and the equivalent resistance Rd will be described in detail below.

When the elapsed time from turning on the switch SW in the equivalent circuit of FIG. Also, the equation of the transient response of the voltage Vcs during the analysis period Tc is represented by the following equation (10).

Equations (11) and (12) below can be derived from Equations (9) and (10) above. The following formula (11) is a formula obtained by summarizing the above formula (9) into a term containing Ld, a term containing Rd, and other terms. Further, the following formula (12) is a formula obtained by subtracting the above formula (9) from the above formula (10) into a term containing Ld, a term containing Rd, and other terms.

Here, as shown in the following formulas (13) to (18), some of the terms of the above formulas (11) and (12) are replaced with a, b, c, d, e, and f, respectively. , the above formulas (11) and (12) can be represented by the following formulas (19) and (20), respectively.

Here, when the above equations (19) and (20) are solved for Ld and Rd respectively, the equivalent inductor Ld and the equivalent resistance Rd can be expressed by the following equations (21) and (22), respectively.

As can be understood from the above equations (21) and (22), the values of a to f can be obtained at any time (sampling point) of the waveforms of the voltages Vcd and Vcs. It is possible to calculate the values of the equivalent inductor Ld and the equivalent resistance Rd at an arbitrary time (sampling point). Specifically, the parameter calculator 5 calculates the values of the equivalent inductor Ld and the equivalent resistance Rd by the following method.

Parameter calculator 5 calculates a to f based on the measured values of voltages Vcd and Vcs and formulas (13) to (18), and calculates a to f based on the calculated a to f and formulas (21) and (22). to calculate the values of the equivalent inductor Ld and the equivalent resistance Rd.
For example, first, the parameter calculator 5 determines the analysis period Tc. For example, as shown in FIG. 3, the parameter calculator 5 sets the sampling point (time) t1 at which the voltage Vcd is 90% of the positive peak value (maximum value Vmax) and the voltage Vcd at the negative peak value (minimum value). Vmin) and the sampling point (time) t2 at which 90% of Vmin) is detected. The parameter calculator 5 sets the period between the sampling point t1 and the sampling point t2 as the analysis period Tc, and sets the time when the switch SW is turned on as t=0.

Next, the parameter calculator 5 performs a known smoothing process, for example, on the time-series data of the measured value of the voltage Vcd and the time-series data of the measured value of the voltage Vcs in the analysis period Tc. For example, the parameter calculator 5 obtains smoothed measured values of the voltages Vcd and Vcs by calculating moving averages of time-series data of the measured values of the voltages Vcd and Vcs in the analysis period Tc.

を夫々算出する。例えば、パラメータ算出部５は、隣り合う２つのサンプリングポイントのＶｃｄ，Ｖｃｓの測定値を用いて、Ｖｃｓを時間ｔによって一階微分した値、Ｖｃｓを時間ｔによって二階微分した値、Ｖｃｓを時間ｔによって三階微分した値、Ｖｃｄを時間ｔによって一階微分した値、Ｖｃｄを時間ｔによって二階微分した値、およびＶｃｄを時間ｔによって三階微分した値をそれぞれ算出する。 Next, the parameter calculator 5 uses the smoothed measured values of the voltages Vcd and Vcs to

are calculated respectively. For example, the parameter calculator 5 uses the measured values of Vcd and Vcs at two adjacent sampling points to obtain a value obtained by first differentiating Vcs with respect to time t, a value obtained by differentiating Vcs secondly with respect to time t, and comparing Vcs with time t. , a value obtained by first differentiating Vcd by time t, a value obtained by secondly differentiating Vcd by time t, and a value obtained by differentiating Vcd by three times by time t are calculated.

Here, the values of the impulse voltage applying capacitor Cs and the current limiting resistor Rs are known. Also, the value of the equivalent capacitor Cd of the winding 11 is estimated by the method described above and stored in the storage unit 8 .

とを、上記式（１３）乃至（１８）に代入することにより、任意の時刻（サンプリングポイント）におけるａ，ｂ，ｃ，ｄ，ｅ，ｆをそれぞれ算出する。 The parameter calculator 5 calculates the values of the impulse voltage applying capacitor Cs, the current limiting resistor Rs, and the equivalent capacitor Cd, which are stored in the storage unit 8.

are substituted into the above equations (13) to (18) to calculate a, b, c, d, e, and f at an arbitrary time (sampling point).

Next, the parameter calculator 5 substitutes the calculated values of a, b, c, d, e, and f into the above equations (21) and (22) to obtain the values of the equivalent inductor Ld and the equivalent resistance Rd. are calculated respectively.

The parameter calculator 5 calculates the values of the equivalent inductor Ld and the equivalent resistance Rd every five hours (sampling points) by performing the above calculation for each sampling point (unit time) in the analysis period Tc. The parameter calculation unit 5 stores the calculated values of the equivalent inductor Ld and the equivalent resistance Rd for each unit time in the storage unit 8 as the analysis result information 83 .
Thereby, temporal changes in the equivalent inductor Ld and the equivalent resistance Rd in the analysis period Tc can be calculated.

Information necessary for calculating the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd may be stored in the storage unit 8 in advance. For example, the information of the above formula (8), the above formulas (13) to (18), the above formula (21), and the above formula (22), the value of the current limiting resistor Rs, and the value of the impulse voltage applying capacitor Cs is stored in the storage unit 8 in advance as the formula 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 mathematical formula information 82 .

The parameter calculation unit 5 reads out the mathematical expression information 82 and the measured value information 81 stored in the storage unit 8 and performs the above calculations to obtain the values of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd of the winding 11. Each value can be calculated.

8 to 10 are diagrams showing an example of analysis results of the equivalent inductor Ld and the equivalent resistance Rd of the winding 11 by the test apparatus 1 when the winding 11 is not magnetically saturated.
11 to 13 are diagrams showing an example of analysis results of the equivalent inductor Ld and the equivalent resistance Rd of the winding 11 by the test apparatus 1 when magnetic saturation occurs in the winding 11. FIG.

8 to 10, after charging the impulse voltage applying capacitor Cs to 100 V, the switch SW is turned on at time t=0 to apply a voltage to the winding 11 to be tested. A waveform 210 of voltage Vcd, a waveform 211 of equivalent inductor Ld, and a waveform 212 of equivalent resistance Rd are respectively shown when magnetic saturation does not occur in line 11 .

11 to 13, after charging the impulse voltage application capacitor Cs to 300 V, the switch SW is turned on at time t=0 to apply a voltage to the winding 11 under test. , waveform 220 of voltage Vcd, waveform 221 of equivalent inductor Ld, and waveform 222 of equivalent resistance Rd when magnetic saturation occurs in winding 11, respectively.

8 to 13, the horizontal axis represents the number of samplings (sampling points) per unit time h by the measurement unit 4, that is, the elapsed time. 8 and 11, the vertical axis represents voltage [V]. 9 and 12, the vertical axis represents inductance [H]. 10 and 13, the vertical axis represents resistance [Ω].

When magnetic saturation does not occur in the winding 11, the value of the equivalent inductor Ld is about 1 mH and stable, as shown in FIG. Also, as shown in FIG. 10, the value of the equivalent resistance Rd varies, but is about 43Ω on average. In order to further suppress variations in the equivalent resistance Rd, instead of performing the moving average processing on the time-series data of the measured values of the voltages Vcd and Vcs as described above, other known smoothing processing is performed. good too.

When magnetic saturation occurs in the winding 11, as shown in FIGS. 12 and 13, the values of the equivalent inductor Ld and the equivalent resistance Rd fluctuate greatly compared to when magnetic saturation does not occur. Diverge at the sampling points. The average value of the equivalent inductor Ld when magnetic saturation occurs in the winding 11 is about one tenth of that when magnetic saturation does not occur, and the average value of the equivalent resistance Rd is 20 to 30Ω.

As described above, when magnetic saturation occurs, the values of equivalent inductor Ld and equivalent resistance Rd may diverge at some sampling points. Therefore, the waveforms of the equivalent inductor Ld and the equivalent resistance Rd may be expressed in another form.

FIGS. 14 and 15 are diagrams showing examples of waveforms in another format representing the values of the equivalent inductor Ld and equivalent resistance Rd of the winding 11 measured by the test apparatus 1. FIG.

FIG. 14 shows a waveform 230 showing temporal changes in "1/Ld", which is the reciprocal of the value of the equivalent inductor Ld. FIG. 15 shows a waveform 231 representing temporal changes in the value "Rd/Ld" obtained by dividing the value of the equivalent resistance Rd by the value of the equivalent inductor Ld. In FIG. 14, the horizontal axis represents sampling points (elapsed time) per unit time h by the measuring unit 4, and the vertical axis represents 1/Ld [1/H]. In FIG. 15, the horizontal axis represents sampling points (elapsed time) per unit time h by the measuring unit 4, and the vertical axis represents Rd/Ld [Ω/H].

As shown in FIGS. 14 and 15, by representing the equivalent inductor Ld and the equivalent resistance Rd by different waveforms, the waveforms do not diverge even when magnetic saturation occurs. analysis becomes easier.

In addition to the function of individually calculating the values of the equivalent inductor Ld, equivalent capacitor Cd, and equivalent resistance Rd related to the winding 11 to be inspected, the test apparatus 1 has the calculated equivalent inductor Ld, equivalent capacitor Cd, and equivalent It has a waveform display function for displaying a waveform showing the temporal change of the resistance Rd. The waveform display function will be described in detail below.

In the test apparatus 1 shown in FIG. 1, the waveform generation section 6 generates waveform data 84 indicating temporal changes in at least one of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd calculated by the parameter calculation section 5. to generate For example, based on the analysis result information 83 and the measured value information 81 stored in the storage unit 8, the waveform generation unit 6 generates, for example, waveform data indicating temporal changes in Vcd, Icd, Cd, Ld, and Rd. 84 is generated and stored in the storage unit 8 .

The display unit 7 displays a waveform based on the waveform data 84 generated by the waveform generation unit 6 on the screen.

FIG. 16 is a diagram showing an example of the display screen of the test apparatus 1. As shown in FIG.
As shown in FIG. 16 , 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. 16, the test apparatus 1 has a power button 30 for activating the test apparatus 1, a start button 31 for starting the test, a stop button 32 for stopping the test, and the like. may

For example, when the user operates the instruction input unit 3 to instruct display of a waveform of a specific physical quantity, the display unit 7 reads the waveform data 84 of the physical quantity specified by the user from the storage unit 8, and displays the display 70. to display. For example, at least one of waveforms 120-122, 210-212, 220-222, 230, and 231 shown in FIGS. 16 shows a case where the waveform 300 of the voltage Vcd is displayed on the display 70. As shown in FIG.

The display unit 7 may display multiple waveforms at the same time. For example, the waveforms of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd may be displayed side by side vertically or horizontally on the screen of the display 70 .

In addition, as described above, the display unit 7 may display the measured waveform on the display 70 in response to the operation of the instruction input unit 3 by the user, or the parameters (Ld, Cd, Rd ), the measured waveform may be displayed on the display 70 regardless of the presence or absence of an instruction from the user.

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

FIG. 17 is a flow chart showing the flow of the method for analyzing the winding 11 using the test apparatus 1 according to this embodiment.

For example, after the user operates the power 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 voltages Vcd and Vcs, and the like 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 S2). 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, a voltage is applied between the external terminals T1 and T2.

At the same time as step S4, for example, the test apparatus 1 starts measuring the voltage Vcd between the external terminals T1 and T2 and the voltage Vcs of the impulse voltage applying capacitor Cs (step S5). Specifically, as described above, the measuring unit 4 measures the voltage Vcd between the external terminals T1 and T2 and the voltage Vcs across the impulse voltage applying capacitor Cs based on the sampling period set in step S1. , voltages Vcd and Vcs are stored in the storage unit 8 as measured value information 81 .

Note that, as described above, instead of measuring the voltage Vcs of the impulse voltage applying capacitor Cs, the measuring unit 4 measures the current Irs flowing through the current limiting resistor Rs or the voltage Vrs of the current limiting resistor Rs. A measured value of the voltage Vcs may be calculated based on the measured value.

Next, the parameter calculation unit 5 sets the analysis period Tb for analyzing the equivalent capacitor Cd of the winding 11 and the analysis period Tc for analyzing the values of the equivalent inductor Ld and the equivalent resistance Rd by the method described above. Determine (step S6).

Next, the parameter calculation unit 5 uses the measurement values of the voltages Vcd and Vcs during the analysis period Tb set in step S6 and the mathematical expression information 82 stored in the storage unit 8 to calculate the winding 11 is calculated (step S7).

Next, the parameter calculation unit 5 uses the measurement values of the voltages Vcd and Vcs in the analysis period Tc set in step S6 and the mathematical expression information 82 stored in the storage unit 8 to calculate the winding 11 , the value of the equivalent inductor Ld and the value of the equivalent resistance Rd are calculated (step S8).

Next, the waveform generation unit 6 generates the measured values of the voltages Vcd and Vcs obtained in step S5 and the equivalent inductor Ld, equivalent capacitor Cd, and equivalent Waveform data 84 is generated based on the value of the resistor Rd (step S9).

Next, the display unit 7 displays a waveform on the screen of the display 70 of the test apparatus 1 based on the waveform data 84 generated in step S9 (step S10).

Note that the above-described waveform data generation processing (step S9) and waveform display processing (step S10) 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, the test apparatus 1 according to the present embodiment has the winding 11 to be tested connected between the external terminal T1 and the external terminal T2 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 voltage Vcd between the external terminals T1 and T2 measured by the measurement unit 4, and It has a parameter calculator 5 for calculating based on the measured value of the voltage Vcs across the impulse voltage applying capacitor Cs.

Specifically, the parameter calculation unit 5 calculates the Using the measured values of the voltage Vcd and the voltage Vcs, the equivalent inductor Ld, the equivalent capacitor Cd, and the equivalent resistance Rd for the winding 11 in the analysis period Tc, the impulse voltage application capacitor Cs, and the current limiting resistor Rs are calculated. A value per unit time of at least one of the equivalent inductor Ld and the equivalent resistance Rd for the winding 11 is calculated by performing a regression analysis based on the equations of the transient response of the voltage Vcd and the voltage Vcs in the circuit.

According to the test apparatus 1 having such a configuration, not only the transient response of the voltage Vcd but also the transient response of the voltage Vcs across the impulse voltage applying capacitor Cs is measured as in the conventional test apparatus, and the equivalent inductor is measured. Since the values of Ld and equivalent resistance Rd are calculated, the values of equivalent inductor Ld and equivalent resistance Rd can be calculated for each sampling point (unit time) of measurement by measurement unit 4 . That is, according to the test apparatus 1, temporal changes in the values of the equivalent inductor Ld and the equivalent resistance Rd can be calculated. This enables the user to analyze changes in the characteristics of the winding 11 when magnetic saturation occurs in the winding 11 to be tested.

Further, in the test apparatus 1, the transient response equation of the voltage Vcd as the first voltage is represented by the above equation (9), and the transient response equation of the voltage Vcs as the second voltage is represented by the above equation (10). expressed.
According to this, the values of the equivalent inductor Ld and the equivalent resistance Rd for each unit time can be calculated more accurately and easily.

Further, the parameter calculation unit 5 calculates the voltage Vcd and Based on the measured value of the voltage Vcs, the value of the equivalent capacitor Cd is calculated.
According to this, the value of the equivalent capacitor Cd can be easily calculated using a simple equation based on an equivalent circuit ignoring the equivalent inductor Ld and the equivalent resistance Rd.

In addition, the parameter calculator 5 calculates the amount of change in the charge of the equivalent capacitor Cd per unit time h and the change in the voltage Vcd per unit time h, which are represented by the measured value of the voltage Vcd and the measured value of the voltage Vcs per unit time h. The value of the equivalent capacitor Cd is calculated based on the relational expression with the quantity. More specifically, the parameter calculator 5 calculates the value of the equivalent capacitor Cd based on the above equation (8).
This makes it possible to accurately calculate the value of the equivalent capacitor Cd using a simpler equation.

Further, the parameter calculator 5 acquires sampling data including the measured value of the voltage Vcd and the measured value of the voltage Vcs sampled by the measuring unit 4 every unit time h, and obtains sampling data of two adjacent sampling points. , the value of the equivalent capacitor Cd is calculated for each data pair.
According to this, since the value of the equivalent capacitor Cd for each unit time h can be obtained, the temporal change in the value of the equivalent capacitor Cd can be calculated. Further, the value (fixed value) of the equivalent capacitor Cd of the winding 11 can be estimated by calculating the average value or median value of the equivalent capacitor Cd for each unit time h.

As described above, according to the test apparatus 1 according to the present embodiment, it is possible to accurately calculate parameters related to the winding to be tested even when magnetic saturation occurs.

Also, the analysis period Tb for the equivalent capacitor Cd is the period immediately after the switch SW is turned on. According to this, the value of the equivalent capacitor Cd can be obtained before calculating the equivalent inductor Ld and the equivalent resistance Rd, so that subsequent analysis processing for the equivalent inductor Ld and the equivalent resistance Rd can be quickly performed. .

In addition, the parameter calculator 5 sets the analysis period Tb for the equivalent capacitor Cd to a predetermined period Tx1 immediately after the switch SW is turned on during the period in which the voltage Vcd is rising, as shown in FIG. , and a predetermined period Tx2 immediately before the voltage Vcd reaches the maximum value Vmax of the voltage Vcd.

According to this, as described above, it is possible to suppress the effects of ringing caused by parasitic capacitance and parasitic inductance and waveform distortion caused by the influence of a control circuit (not shown). can be calculated with higher accuracy.

Further, as shown in FIG. 4, the analysis period Tb is defined as the measured value of the voltage Vcd from the time tα when the measured value of the voltage Vcd is α (0≦α<100)% of the maximum value Vmax of the voltage Vcd. The parameter calculator 5 can easily determine the analysis period Tb by setting the period up to the time tβ when β (α<β≦100)% of the maximum value Vmax of Vcd.

In addition, in the test apparatus 1 according to the present embodiment, the display unit 7 displays at least one value of the equivalent capacitor Cd, the equivalent inductor Ld, and the equivalent resistance Rd related to the winding 11 under test calculated by the parameter calculation unit 5. Displays waveforms showing changes over time.

This makes it easier for the user to determine whether or not magnetic saturation occurs, and to analyze changes in equivalent capacitor Cd, equivalent inductor Ld, and equivalent resistance Rd caused by magnetic saturation.

In addition, when displaying waveforms related to the calculated parameters, the display unit 7 displays the values of the equivalent inductor Ld and the equivalent resistance Rd in addition to the waveforms showing temporal changes in the values of the equivalent inductor Ld and the equivalent resistance Rd. It is possible to display changes over time as another form of waveform. For example, as described above, a waveform indicating a temporal change in the reciprocal (1/Ld) of the value of the equivalent inductor Ld, or a value (Rd/Ld) obtained by dividing the value of the equivalent resistance Rd by the value of the equivalent inductor Ld. It is possible to display waveforms that show changes over time.
According to this, even if there is a period during which the values of the equivalent inductor Ld and the equivalent resistance Rd diverge due to the occurrence of magnetic saturation, the numerical values do not diverge as shown in FIGS. Since the waveform can be changed and displayed, it becomes easier for the user to analyze the characteristics of the winding 11 .

<<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 embodiment, the value of the equivalent capacitor Cd is calculated by the method described above and stored in the storage unit 8, and the value of the equivalent capacitor C stored in the storage unit 8 is used to calculate the equivalent inductor Ld and the equivalent resistance Although the case of calculating the value of Rd has been exemplified, the present invention is not limited to this.
For example, when it is known that the value of the equivalent capacitor Cd of the winding 11 to be tested is sufficiently smaller than the value of the impulse voltage applying capacitor Cs, the value of the equivalent capacitor Cd is expressed as Cd=Cs/100. is assumed, and the assumed value is stored in the storage unit 8 in advance. For example, the user operates the instruction input unit 3 to input the value of the equivalent capacitor Cd, and the parameter calculation unit 5 stores the value input by the user in the storage unit 8 . Then, the parameter calculator 5 may use the values of the equivalent capacitors stored in the storage unit 8 to calculate the values of the equivalent inductor Ld and the equivalent resistance Rd by the method described above. According to this, since the test apparatus 1 does not need to analyze the equivalent capacitor Cd, the analysis of the winding 11 can be completed in a shorter time.

Further, in the above-described embodiment, the unit time h has been described as a time corresponding to one sampling period by the measurement unit 4, but it is not limited to this. For example, the unit time h may be a time based on a sampling cycle such as 2 sampling cycles or 3 sampling cycles.

In the above embodiment, the average value Iave of the current Icd in the period from time t=a to time t=a+h is the average value of the current Icd at the two sampling points (see equation (3)). Although exemplified, it is not limited to this. For example, the average value Iave may be the average value of currents Icd at three or more sampling points.

Moreover, although the test apparatus 1 includes the backflow prevention diode D in the above embodiment, the test apparatus 1 may not include the backflow prevention diode D. FIG. If the test apparatus 1 is not required to have a waveform display function, the test apparatus 1 does not have to have the waveform generation section 6 and the display section 7 .

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 diagram 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... Testing apparatus 2... Impulse voltage generation circuit 3... Instruction input part 4... Measurement part 5... Parameter calculation part 6... Waveform generation part 7... Display part 8... Storage part 81... Measured value information , 82...equation information, 83...analysis result information, 84...waveform data, Cs...capacitor for impulsive voltage application, Cd...equivalent capacitor of winding 11, Ld...equivalent inductor of winding 11, Rd...equivalent of winding 11 Resistance, Rs... Current limiting resistor, D... Rectifying element (backflow prevention diode), E... Impulse voltage, Ta, Tb, Tc... Analysis period, Vmax... Maximum value of voltage Vcd, Vmin... Minimum value of voltage Vcd, T1 ... external terminal (first external terminal), T2 ... external terminal (second external terminal), 70 ... display.

Claims (12)

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 for turning on the switch in response to an instruction to start testing;
a measuring unit that measures a first voltage between the first external terminal and the second external terminal and a second voltage across the impulse voltage applying capacitor;
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 an equivalent capacitor connected between the first external terminal and the second external terminal. change over time in the value of at least one of the equivalent inductor and the equivalent resistance when the winding is equivalently represented by an equivalent resistance connected in series with the equivalent inductor between a second external terminal , a parameter calculator that calculates based on the measured value of the first voltage and the measured value of the second voltage measured by the measuring unit;
a storage unit that stores measured value information including the measured value of the first voltage and the measured value of the second voltage measured by the measuring unit and the value of the equivalent capacitor;
The parameter calculation unit
every unit time 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 windings is started, which is stored in the storage unit using the measured value of the first voltage and the measured value of the second voltage of and the value of the equivalent capacitor stored in the storage unit, the equivalent inductor of the winding during the predetermined period of time; The equation of the transient response of the first voltage and the equation of the transient response of the second voltage in an equivalent circuit composed of the equivalent capacitor, the equivalent resistance, the impulse voltage applying capacitor, and the current limiting resistor A test device that calculates the value of at least one of the equivalent inductor and the equivalent resistance for each unit time by performing regression analysis based on the test device. In the testing device according to claim 1,
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, and the first voltage is Vcd. , where the second voltage is Vcs and the time is t, the equation of the transient response of the first voltage is expressed by the following equation (1), and the equation of the transient response of the second voltage is expressed by the following equation (2) ) test equipment.

In the test device according to any one of claims 1 or 2,
The parameter calculation unit
Measurement of the first voltage and measurement of the second voltage during a first period during which the first voltage is rising immediately after the switch is turned on and during which the current flowing through the equivalent inductor can be considered to be zero. A test device that calculates the value of the equivalent capacitor based on the value and stores it in the storage unit. In the testing device according to claim 3,
The parameter calculator calculates an amount of change in the charge of the equivalent capacitor in the unit time and the first voltage in the unit time, which are represented by the measured value of the first voltage and the measured value of the second voltage in the unit time. 1. A testing device that calculates the value of the equivalent capacitor based on a relational expression with the amount of change in voltage. In the test device according to claim 4,
The measured value of the second voltage at the time a in the first period is Vcs|t=a, the measured value of the first voltage at the time a is Vcd|t=a, and the unit time h from the time a Vcs|t=a+h is the measured value of the second voltage at the advanced time a+h, Vcd|t=a+h is the measured value of the first voltage at the time a+h, Rs is the value of the current limiting resistor, and Rs is the value of the equivalent capacitor When the value is Cd,
The parameter calculation unit calculates the value of the equivalent capacitor for each unit time based on the following formula (3).

In the test device according to any one of claims 3 to 5,
The measurement unit samples the first voltage and the second voltage for each unit time,
The parameter calculator acquires sampling data including the measured value of the first voltage and the measured value of the second voltage sampled by the measuring unit, and integrates the sampling data of two sampling points adjacent to each other. A testing device that calculates the value of the equivalent capacitor for each pair of data to be set. In the test device according to any one of claims 3 to 6,
The first period includes a predetermined period immediately after the switch is turned on and a predetermined period immediately before the first voltage reaches the maximum value of the first voltage. test equipment. In the test device according to claim 7,
In the first period, the measured value of the first voltage reaches the maximum value of the first voltage from the time when the measured value of the first voltage becomes α (0≦α<100)% of the maximum value of the first voltage. It is the period until the time when β (α < β ≤ 100)% of the value is reached. In the test device according to any one of claims 1 to 8,
a waveform generation unit for generating waveform data indicating a temporal change in at least one of the equivalent capacitor, the equivalent inductor, and the equivalent resistance calculated by the parameter calculation unit; and displaying a waveform based on the waveform data. and a display unit for testing. In the test device according to claim 9,
The test apparatus, wherein the display section displays a waveform representing a temporal change in the reciprocal of the value of the equivalent inductor. In the test device according to claim 9 or 10,
The test apparatus, wherein the display unit displays a waveform representing a temporal change in a value obtained by dividing the value of the equivalent resistance by the value of the equivalent inductor. 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 a first voltage between the first external terminal and the second external terminal and a second voltage across the impulse voltage applying capacitor;
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 an equivalent capacitor connected between the first external terminal and the second external terminal. Time change in the value of at least one of the equivalent inductor and the equivalent resistance when the winding is equivalently represented by an equivalent resistance connected in series with the equivalent inductor between a second external terminal is calculated based on the measured value of the first voltage and the measured value of the second voltage measured in the second step,
The third step is
a measurement value of the first voltage per unit time during 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 is started; and Using the measured value of the second voltage and the value of the equivalent capacitor stored in the test device, the equivalent inductor, the equivalent capacitor, and the equivalent resistance of the winding over the predetermined period of time. , the impulse voltage applying capacitor and the current limiting resistor, by performing a regression analysis based on the equation of the transient response of the first voltage and the equation of the transient response of the second voltage in the equivalent circuit, A test method for calculating a value per unit time of at least one of the equivalent inductor and the equivalent resistance.

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