High-frequency power inductance loss testing device and method

Abstract

The invention discloses a high-frequency power inductance loss testing device and method. The device comprises a driving controller, a direct-current power supply, a DC / AC inverter, an LC power frequency selection circuit and an oscilloscope. The output end of the direct-current power supply is connected with the input end of the DC / AC inverter, the output end of the DC / AC inverter is connected with the input end of the LC power frequency-selecting circuit, the output end of the LC power frequency-selecting circuit is connected to the inductor to be tested, and the inductor to be tested is further connected with the non-inductive resistor; the LC power frequency selection circuit is in signal connection with the driving controller, and the driving controller is in signal connection with the DC / AC inverter. Test parameters can be adjusted according to different working conditions, the current of the tested inductor is obtained by sampling the non-inductive resistor, and the inductance loss test flexibility and the high-frequency test precision are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic device loss testing, and in particular to a high-frequency power inductor loss testing device and method. Background Art

[0002] In power electronic products, inductor devices are often used, especially in high-frequency and high-power products. Inductor loss accounts for a large proportion of the total product loss. Therefore, inductor loss testing and research are crucial to improving the efficiency of the entire product.

[0003] At present, high-frequency and high-power inductor losses are usually tested on the products on the machine with a power analyzer, but this test method has two problems: First, if there is a problem with the inductor when testing on the product on the machine, it is easy to cause abnormal indicators or even failure of the whole machine, which is risky; second, the power analyzer must be compatible with non-contact current testing (it cannot destroy the status of the product on the machine). At present, most Hall-type current sensors are used to sample the current of the tested device, which is easy to cause current phase shift in the back-end signal processing and filtering, and the accuracy is relatively poor in high-frequency tests above 20KHz (power analyzers are currently mainly developed for low-frequency 50HZ and 115Hz needs. The accuracy of low-frequency tests is little affected by phase errors, while the accuracy of high-frequency tests is greatly affected by phase errors). Another test method is to use a combination of a high-frequency power source and a power analyzer to test the inductor separately. This test method can avoid the impact of the inductor on the whole machine, but the disadvantage is that it is expensive and the problem of high-frequency accuracy of the power analyzer still exists. Summary of the invention

[0004] To solve the above problems, the present invention provides a high-frequency power inductor loss test device and method. The device can independently test a single inductor device, does not require a high-frequency power amplifier, has low cost, and the system is simple and easy to build. The test parameters can be adjusted according to different working conditions, and it has strong versatility. The current of the inductor under test is sampled and acquired using a non-inductive resistor, and has relatively good high-frequency test accuracy.

[0005] The present invention provides a high-frequency power inductor loss test device, and the specific technical solution is as follows:

[0006] The device includes a drive controller, a DC power supply, a DC / AC inverter, an LC power frequency selection circuit and an oscilloscope;

[0007] The output end of the DC power supply is connected to the input of the DC / AC inverter, the output end of the DC / AC inverter is connected to the input of the LC power frequency selection circuit, the output of the LC power frequency selection circuit is connected to the inductor to be measured, and the inductor to be measured is also connected to a non-inductive resistor; the LC power frequency selection circuit is connected to the drive controller signal, and the drive controller is connected to the DC / AC inverter signal.

[0008] Furthermore, the DC power supply is an adjustable DC power supply.

[0009] Furthermore, the drive controller adopts UC3875, and the drive controller is serially connected with a frequency modulation resistor and a frequency modulation capacitor in parallel.

[0010] Furthermore, the frequency modulation resistor is 32KΩ, and the frequency modulation capacitor is 1nF.

[0011] Furthermore, the DC / AC inverter includes a plurality of MOS tubes and diodes;

[0012] There are four MOS tubes and four diodes respectively, and the DC / AC inverter forms two groups of series-connected units in which the source and drain of two MOS tubes are connected. The source and drain of the MOS tubes not connected in series in the two groups of series-connected units are connected correspondingly to form a parallel structure, and are simultaneously connected to the output of the drive controller. The source and drain of each MOS tube are respectively connected to the positive and negative electrodes of the corresponding diode, and the series connection of the MOS in the two groups of series-connected units constitutes an output port connected to the input of the LC power frequency selection circuit.

[0013] Furthermore, the LC power frequency selection circuit includes a filter inductor, a filter capacitor and a DC blocking capacitor. The filter capacitor is connected to the voltage output end of the DC / AC inverter through the filter inductor and the DC blocking capacitor. One end of the filter inductor and the DC blocking capacitor connected to the filter capacitor constitutes an output port connected to the inductor under test.

[0014] Furthermore, the filter inductor is 2.53 μH, the filter capacitor is 1 μF, and the DC blocking capacitor is 5 μF.

[0015] The present invention also provides a high-frequency power inductor loss test method, the specific process is as follows:

[0016] S1: Get the actual operating frequency and current of the inductor being measured;

[0017] S2: adjust the frequency of the drive controller to send out a drive signal with the same frequency as f;

[0018] S3: The DC / AC inverter converts the input DC voltage into a square wave voltage with a frequency of f;

[0019] S4: The LC power frequency selection circuit performs frequency selection filtering on the square wave voltage and outputs a sine wave with a frequency of f;

[0020] S5: Apply the output sine wave voltage to both ends of the inductor to obtain the inductor voltage U L ;

[0021] S6: Get the inductor current I of the inductor under test L ;

[0022] S7: Process the inductor voltage and the inductor current based on the filter to obtain the inductor loss.

[0023] Furthermore, the inductor current I L , the acquisition process is as follows:

[0024] A non-inductive resistor with a set resistance value is used as a current sampling resistor and connected in series with the inductor to be measured;

[0025] The voltage on the non-inductive resistor is detected and obtained, and the inductor current of the inductor is calculated. Further, in step S7, the loss of the inductor is expressed as follows:

[0026] P L =∫(U L *I L )dt

[0027] Among them, P L Indicates the loss of inductance, U L Inductor voltage, I L represents the inductor current.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention adjusts the frequency of the driving controller so that the DC / AC inverter converts the input DC voltage into a square wave voltage of the same frequency, and at the same time enables the LC power frequency selection circuit to output a sine wave of the same frequency, thereby improving the versatility of the device. At the same time, the device performs current sampling through a non-inductive resistor, thereby improving the accuracy of high-frequency testing, solving the problems of existing inductance loss testing methods such as high risk, high cost, and insufficient high-frequency testing accuracy, and meeting application testing requirements such as low risk, high frequency, and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention.

[0031] Figure 2 It is a schematic diagram of the structure of the DC / AC inverter of the present invention.

[0032] Figure 3 It is a schematic diagram of the structure of the LC power frequency selection circuit of the present invention.

[0033] Figure 4 It is a schematic diagram of the structure of the frequency-adjustable part of the drive controller of the present invention.

[0034] Figure 5 It is a schematic flow chart of the method of the present invention.

[0035] Figure 6It is a schematic diagram of the simulation results of the inductance loss test of the present invention. DETAILED DESCRIPTION

[0036] The following description clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the embodiments of the present invention, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the invention product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship in which the invention product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0038] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Example 1

[0040] Embodiment 1 of the present invention discloses a high-frequency power inductor loss test device, such as Figure 1 As shown, the details are as follows:

[0041] The device includes a drive controller, a DC power supply, a DC / AC inverter, an LC power frequency selection circuit and an oscilloscope;

[0042] The output end of the DC power supply is connected to the input of the DC / AC inverter, the output end of the DC / AC inverter is connected to the input of the LC power frequency selection circuit, the output of the LC power frequency selection circuit is connected to the inductor to be measured, and the inductor to be measured is also connected to a non-inductive resistor; the LC power frequency selection circuit is connected to the drive controller, and the drive controller is connected to the DC / AC inverter.

[0043] As a preferred embodiment, the DC power supply is an adjustable DC power supply;

[0044] The drive controller adopts UC3875, such as Figure 4 As shown, the drive controller is connected in series with a frequency modulation resistor R1 and a frequency modulation capacitor C1 in parallel;

[0045] The drive controller is grounded via a frequency modulation resistor R1 and a frequency modulation capacitor C1 connected in parallel.

[0046] Specifically, the frequency modulation resistor R1 is 32KΩ, and the frequency modulation capacitor C1 is 1nF.

[0047] As a preferred embodiment, the DC / AC inverter includes a plurality of MOS tubes and diodes;

[0048] There are four MOS tubes and four diodes respectively, and the DC / AC inverter forms two groups of series-connected units in which the source and drain of two MOS tubes are connected. The source and drain of the MOS tubes not connected in series in the two groups of series-connected units are connected correspondingly to form a parallel structure, and are simultaneously connected to the output of the drive controller. The source and drain of each MOS tube are respectively connected to the positive and negative electrodes of the corresponding diode, and the series connection of the MOS in the two groups of series-connected units constitutes an output port connected to the input of the LC power frequency selection circuit.

[0049] Specifically, Figure 2 As shown, the four MOS transistors are respectively marked as S1, S2, S3 and S4, and the four diodes are respectively marked as D1, D2, D3 and D4; the source of the MOS transistor S1 is connected to the drain of the MOS transistor S2, and the source of the MOS transistor S3 is connected to the drain of the MOS transistor S4; the drain of the MOS transistor S1 is connected to the drain of the MOS transistor S3, and the source of the MOS transistor S2 is connected to the source of the MOS transistor S4, and the drains of the MOS transistors S1 and S3 and the sources of the MOS transistors S2 and S2 are connected to the voltage input of the adjustable DC power supply Vin as voltage input ports.

[0050] As a preferred embodiment, Figure 3 As shown, the LC power frequency selection circuit includes a filter inductor L s 、Filter capacitor C p and the DC blocking capacitor C s , the filter capacitor C p Through the filter inductor L s and the DC blocking capacitor C s The voltage output terminal of the DC / AC inverter is connected to the filter inductor L s and the DC blocking capacitor C s With the filter capacitor C p One end of the connection constitutes an output port connected to the inductor to be measured.

[0051] Specifically, the filter inductor Ls is 2.53μH, the filter capacitor C p is 1μF, the DC blocking capacitor C s is 5μF.

[0052] Example 2

[0053] Embodiment 2 of the present invention discloses a high-frequency power inductor loss test method based on the above-mentioned embodiment 1, such as Figure 5 As shown, the specific steps are as follows:

[0054] S1: Obtain the actual operating frequency and current of the inductor being measured, and determine the parameters f and I L ;

[0055] S2: adjust the frequency of the drive controller to send out a drive signal with the same frequency as f;

[0056] S3: The DC / AC inverter converts the input DC voltage into a square wave voltage with a frequency of f;

[0057] S4: The LC power frequency selection circuit performs frequency selection filtering on the square wave voltage and outputs a sine wave with a frequency of f;

[0058] S5: Apply the output sine wave voltage to both ends of the inductor to obtain the inductor voltage U L ;

[0059] S6: A low-resistance non-inductive resistor with a resistance value of R0 is connected in series with the inductor to be measured as a current sampling resistor, the voltage on the non-inductive resistor is detected and obtained, and the inductor current of the inductor to be measured is calculated, which is the inductor current I L ;

[0060] S7: Processing the inductor voltage and the inductor current based on the filter to obtain the inductor loss;

[0061] Specifically, the loss of inductance is expressed as follows:

[0062] P L =∫(U L *I L )dt

[0063] Among them, P L Indicates the loss of inductance, U L Inductor voltage, I L represents the inductor current.

[0064] Based on the above device method, Figure 6 As shown, it can be seen that the measured inductor voltage U L and the inductor current I LAll are smooth sine waves; the spectrum analysis of the inductor current is done, the typical frequency is 100kHz, the maximum and minimum values ​​of the simulation analysis results are 100.23kHz and 100.08kHz respectively, the frequency error is 0.23%, and the performance of the test device fully meets the requirements of the inductor loss test. Based on this device, a physical comparison test of a company's 30uH AC inductor is carried out, and the test current frequency is 100kHz. The results are shown in Table 1. It can be seen from Table 1 that the test results of the device have a small deviation from the theoretical value and have a relatively high practical value.

[0065] Table 1: Comparison of device inductance test results

[0066]

[0067]

[0068] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A high-frequency power inductor loss test device, characterized in that: The device includes a drive controller, a DC power supply, a DC / AC inverter, an LC power frequency selection circuit and an oscilloscope; The output end of the DC power supply is connected to the input of the DC / AC inverter, the output end of the DC / AC inverter is connected to the input of the LC power frequency selection circuit, the output of the LC power frequency selection circuit is connected to the inductor to be measured, and the inductor to be measured is also connected to a non-inductive resistor; the LC power frequency selection circuit is connected to the drive controller signal, and the drive controller is connected to the DC / AC inverter signal.

2. The high-frequency power inductor loss test device according to claim 1, characterized in that: The DC power supply is an adjustable DC power supply.

3. The high-frequency power inductor loss test device according to claim 1, characterized in that: The driving controller adopts UC3875, and the driving controller is serially connected with a frequency modulation resistor and a frequency modulation capacitor in parallel.

4. The high-frequency power inductor loss test device according to claim 3, characterized in that: The frequency modulation resistor is 32KΩ, and the frequency modulation capacitor is 1nF.

5. The high-frequency power inductor loss test device according to claim 1, characterized in that: The DC / AC inverter includes a plurality of MOS tubes and diodes; There are four MOS tubes and four diodes respectively, and the DC / AC inverter forms two groups of series-connected units in which the source and drain of two MOS tubes are connected. The source and drain of the MOS tubes not connected in series in the two groups of series-connected units are connected correspondingly to form a parallel structure, and are simultaneously connected to the output of the drive controller. The source and drain of each MOS tube are respectively connected to the positive and negative electrodes of the corresponding diode, and the series connection of the MOS in the two groups of series-connected units constitutes an output port connected to the input of the LC power frequency selection circuit.

6. The high-frequency power inductor loss test device according to claim 1, characterized in that: The LC power frequency selection circuit includes a filter inductor, a filter capacitor and a DC blocking capacitor. The filter capacitor is connected to the voltage output end of the DC / AC inverter through the filter inductor and the DC blocking capacitor. One end of the filter inductor and the DC blocking capacitor connected to the filter capacitor constitutes an output port connected to the inductor under test.

7. The high-frequency power inductor loss test device according to claim 6, characterized in that: The filter inductor is 2.53 μH, the filter capacitor is 1 μF, and the DC blocking capacitor is 5 μF.

8. A high-frequency power inductor loss test method, characterized in that: Based on the high-frequency power inductor loss test device described in any one of claims 1 to 8, the specific process of the method is as follows: S1: Get the actual operating frequency and current of the inductor being measured; S2: adjust the frequency of the drive controller to send out a drive signal with the same frequency as f; S3: The DC / AC inverter converts the input DC voltage into a square wave voltage with a frequency of f; S4: The LC power frequency selection circuit performs frequency selection filtering on the square wave voltage and outputs a sine wave with a frequency of f; S5: Apply the output sine wave voltage to both ends of the inductor to obtain the inductor voltage U L ; S6: Get the inductor current I of the inductor under test L ; S7: Process the inductor voltage and the inductor current based on the filter to obtain the inductor loss.

9. The high-frequency power inductor loss test method according to claim 8, characterized in that: The inductor current I L , the acquisition process is as follows: A non-inductive resistor with a set resistance value is used as a current sampling resistor and connected in series with the inductor to be measured; The voltage on the non-inductive resistor is detected and obtained, and the inductor current of the inductor is calculated and obtained.

10. The high-frequency power inductor loss test method according to claim 8, characterized in that: In step S7, the loss of the inductor is expressed as follows: P L =∫(U L *I L )dt Among them, P L Indicates the loss of inductance, U L Inductor voltage, I L represents the inductor current.

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