Alternating current power supply capable of compiling output impedance and method for simulating output impedance

Abstract

The invention provides an AC power supply capable of compiling output impedance and a method for simulating output impedance. The method comprises the following steps. An analog command is selectively provided by the control circuit, and the analog command is associated with a voltage adjustment value and a phase adjustment value of the test circuit. The control circuit calculates the voltage adjustment value and a preset voltage value to form a voltage command. The control circuit calculates the phase adjustment value and a preset phase value to form a phase command. The power supply circuit generates an analog output voltage according to the voltage command and the phase command. Wherein the preset voltage value and the preset phase value are associated with a preset output voltage provided by the power supply circuit, and the analog output voltage is a voltage obtained after the preset output voltage provided by the analog power supply circuit passes through the test circuit.

Description

Technical Field

[0001] The present application relates to an AC power supply and a control method thereof, and more particularly to an AC power supply capable of programming output impedance and a method for simulating output impedance. Background Art

[0002] Generally speaking, after electronic equipment or parts are manufactured, they need to go through a series of tests to ensure their functionality and safety. In order to standardize the test methods and results, the industry has developed many test specifications. For example, the existing test specifications IEC61000-3-3 and IEC61000-3-11 specify that the DUT must undergo voltage fluctuations and detect the DUT's response to a specific voltage difference. In practice, the industry calls the aforementioned test type a flicker test, and in order to implement a flicker test, a traditional AC power supply is often connected to an external test circuit with a series resistor and inductor to meet the requirements of the test specifications IEC61000-3-3 and IEC61000-3-11.

[0003] However, because the test circuit is composed of physical electronic components, if it is to be changed to a different resistance value or inductance value, those with general knowledge in the relevant technical field can understand that it will require hardware replacement, which will not only cause inconvenience in use, but also may affect the accuracy of the measurement. Therefore, the industry needs an AC power supply that can freely set various resistance values ​​or inductance values ​​to facilitate users to perform various test items. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a method for simulating output impedance, which can enable an AC power supply to simulate the situation when connected to a specific output impedance, so that the AC power supply can simulate the output of the corresponding voltage.

[0005] The present application proposes a method for simulating output impedance, which is used for an AC power supply, and the AC power supply includes a control circuit and a power supply circuit. The method includes the following steps. The control circuit selectively provides a simulation command, and the simulation command is associated with a voltage adjustment value and a phase adjustment value of a test circuit. The control circuit calculates the voltage adjustment value and a preset voltage value to form a voltage command. The control circuit calculates the phase adjustment value and the preset phase value to form a phase command. The power supply circuit generates a simulated output voltage according to the voltage command and the phase command. The preset voltage value and the preset phase value are associated with a preset output voltage provided by the power supply circuit, and the simulated output voltage is the voltage after the preset output voltage provided by the simulated power supply circuit passes through the test circuit.

[0006] In some embodiments, the test circuit is composed of at least a resistor and an inductor connected in series, and the simulated output voltage is used to simulate the voltage of the preset output voltage passing through the resistor and the inductor connected in series. The voltage adjustment value simulates the cross-voltage associated with the resistor and the cross-voltage of the inductor, and the phase adjustment value simulates the phase shift caused by the inductor. The cross-voltage of the resistor is the product of the measured value of the output current provided by the power supply circuit and the resistance value of the resistor, and the cross-voltage of the inductor is the product of the measured value of the output current and the impedance value of the inductor. The simulated output voltage is used for flicker testing of the object under test.

[0007] The present application provides an AC power supply with programmable output impedance, which can simulate the situation when connected to a specific output impedance, so that the AC power supply can simulate the output of the corresponding voltage.

[0008] The present application proposes an AC power supply capable of programming output impedance, the AC power supply comprising a control circuit and a power supply circuit. The control circuit selectively provides a simulation command, the simulation command is associated with a voltage adjustment value and a phase adjustment value of a test circuit, the control circuit calculates the voltage adjustment value and a preset voltage value to form a voltage command, and the control circuit calculates the phase adjustment value and a preset phase value to form a phase command. The power supply circuit generates a simulated output voltage according to the voltage command and the phase command. The preset voltage value and the preset phase value are associated with a preset output voltage provided by the AC power supply, and the simulated output voltage is the voltage after the preset output voltage provided by the simulated AC power supply passes through the test circuit.

[0009] In summary, the AC power supply with programmable output impedance and the method for simulating output impedance proposed in the present application calculate the voltage difference of the preset output current flowing through the resistor and inductor in the test circuit by the control circuit, and the power supply circuit uses the voltage difference to adjust the preset output voltage, so that the output voltage of the power supply circuit after adjustment is equivalent to the voltage after the external test circuit is connected. The AC power supply with programmable output impedance and the method for simulating output impedance of the present application do not require hardware replacement, and can simulate various external resistors or inductors to facilitate users to perform various test items.

[0010] The details of other effects and embodiments of the present application are described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 It is based on the functional block diagram of a traditional AC power supply;

[0013] Figure 2 is a functional block diagram of an AC power supply with programmable output impedance according to an embodiment of the present application;

[0014] Figure 3 is a flowchart of a method for simulating output impedance according to an embodiment of the present application.

[0015] Explanation of symbols

[0016] 1 AC power supply 10 control circuit

[0017] 12 Power supply circuit 9 Traditional AC power supply

[0018] 90 control circuit 92 power supply circuit

[0019] 94 Test Circuit L Inductor

[0020] R Resistance DUT

[0021] S20~S26 step flow DETAILED DESCRIPTION

[0022] The positional relationships described in the following embodiments include: up, down, left and right. Unless otherwise specified, they are all based on the directions in which the components are drawn in the drawings.

[0023] Before explaining the AC power supply with programmable output impedance and the method of simulating output impedance described in this application, it is necessary to first understand how the output impedance of a conventional AC power supply is adjusted. Figure 1 , Figure 1 It is based on the functional block diagram of a traditional AC power supply. Figure 1 As shown, the conventional AC power supply 9 has a control circuit 90 and a power supply circuit 92 inside. The power supply circuit 92 is controlled by the digital control command given by the control circuit 90, so that it can provide the output voltage Vo set by the digital control command. However, in order to perform the flicker test of the DUT in accordance with the IEC61000-3-3 and IEC61000-3-11 specifications, the conventional AC power supply 9 needs to be connected to a test circuit 94, and the specific test voltage Vo' required for the test is generated through the resistor R and the inductor L connected in series in the test circuit 94. It can be understood by those with ordinary knowledge in the relevant technical field that a test circuit 94 will only have a set of specific resistors R and inductors L. If the parameters of the resistors R and the inductors L are to be changed, other test circuits must be replaced and installed, which cannot effectively speed up the test.

[0024] Therefore, in order to solve the above-mentioned problem of needing an external test circuit, this embodiment demonstrates an AC power supply capable of programming output impedance. Figure 1 and Figure 2 , Figure 2 1 is a functional block diagram of an AC power supply with programmable output impedance according to an embodiment of the present application. As shown in the figure, the AC power supply with programmable output impedance 1 of this embodiment has a control circuit 10 and a power supply circuit 12. In the absence of an external test circuit 94, the control circuit can simulate the existence of an external test circuit 94, so that the power supply circuit directly outputs the correct test voltage Vo'. The following is an actual example to illustrate how the power supply circuit 12 directly simulates the generation of Figure 1 The test voltage Vo' in.

[0025] In one example, Figure 1 The test voltage Vo' in the equation (1) can be expressed as follows. The equation (1) describes the current path from the power supply circuit 92 to the DUT. The power supply circuit 92 provides a preset output voltage Vo, and then the voltage across the resistor R (V R ) and the voltage across the inductor L (V L ), and finally obtain the test voltage Vo'.

[0026] Vo'=Vo-(V R +V L ) (1)

[0027] In practice, Figure 1 The resistor R and the inductor L in the test circuit 94 should be known values ​​(e.g., values ​​that meet specific test specifications), and the output current of the power supply circuit 12 can be measured to obtain the measured value of the output current Io. At this time, the voltage across the resistor R (V R ) can be expressed as expression (2), the voltage across the inductor L (V L ) can be expressed as expression (3).

[0028] V R =Io×X R =Io×R (2)

[0029] V L =Io××X L =Io×2πfL (3)

[0030] Among them, X R Indicates the impedance value of resistor R, X L represents the impedance value of the inductor L. For the convenience of explanation, expression (2) directly converts the impedance value of the resistor R into R In fact, it is also the resistance value X R, which can be expressed as R. Expression (3) directly expresses the inductance value of the inductor L as L. In other words, expression (2) expresses the voltage across the resistor R (V R ) is the measured value of the feedback output current Io and the resistance value X R The product of the voltage across the inductor L (V L ) is the measured value of the feedback output current Io and the impedance value of the inductor X L The product of . In practice, the resistance value of the resistor R can be 0.4 to 1Ω, the inductance value of the inductor L can be 0.1 to 2mH, and f in the expression (3) can be 50Hz, which is not limited in this embodiment. In other words, returning to the expression (1), as long as the power supply circuit 12 can output the test voltage Vo', it is physically equal to the voltage after the power supply circuit 12 simulates the preset output voltage Vo after passing through the resistor R and the inductor L. In order to achieve the above simulation results, the present embodiment adjusts the command used by the control circuit 10 to control the power supply circuit 12. In an example, when the flicker test is not performed, the control circuit 10 can control the power supply circuit 12 to provide an output voltage Vo with a preset voltage value and a preset phase value. When the flicker test is performed, the control circuit 10 will use the simulation command to adjust the output voltage of the power supply circuit 12 to make it the test voltage Vo'.

[0031] In practice, the control circuit 10 can directly calculate the above expression (2) and expression (3) to obtain the value of (Io×R) and the value of (Io×2πfL), and the value of (Io×R) and the value of (Io×2πfL) can be used to simulate the voltage across the resistor R (V R ) and the voltage across the inductor L (V L ). Next, the control circuit 10 calculates the value of (Io×R) and the value of (Io×2πfL), and the value of (Io×R) and the value of (Io×2πfL) are the voltage adjustment values ​​obtained by the control circuit 10. Here, because the voltage across the resistor R (V R ) and the voltage across the inductor L (V L ) is the voltage drop, so the voltage adjustment value here should be a negative value. A person with ordinary knowledge in the relevant technical field can understand that the voltage across the analog resistor R (V R ) does not affect the phase of the output voltage Vo, but simulates the voltage across the inductor L (V L ) will cause the phase of the output voltage Vo to shift by 90 degrees (lead by 90 degrees), so the phase of the output voltage Vo must be adjusted to simulate the test voltage Vo'. In other words, the control circuit 10 uses the aforementioned voltage adjustment value to simulate the voltage drop of the output voltage Vo passing through the resistor R and the inductor L, and the control circuit 10 also needs a phase adjustment value to simulate the phase difference of the output voltage Vo passing through the resistor R and the inductor L.

[0032] For example, the control circuit 10 can use the phase conversion function H(S) as the phase adjustment value to adjust the phase of the output voltage Vo, such as the following expression (4). Wherein, fz is the zero point of the phase conversion function H(S), and in this embodiment, fz can be set to 0.5Hz (at this time, the phase shift is about 45 degrees). In order to ensure that the phase shift is 90 degrees, 100 times fz can be selected (that is, 50Hz in accordance with the requirements of IEC61000-3-3 and IEC61000-3-11 specifications). In addition, kp is a gain adjustment parameter. This is mainly because after selecting 100 times fz, the gain also becomes 100 times. It is necessary to set kp to 0.01 to correct it back to the original gain value. The linkage between the zero point and the gain adjustment parameter should be understood in the relevant technical field, so this embodiment will not be repeated. In addition, the pole f of the phase conversion function H(S) P1 and f P2 For example, it can be 1.8kHz and 2kHz. One of the functions of designing it in the double pole frequency band of the system is to be used for filtering. Those with ordinary knowledge in the relevant technical field can understand that higher frequency noise will not affect the overall bandwidth of the system.

[0033]

[0034] After the control circuit 10 obtains the voltage adjustment value, it can obtain a voltage command corresponding to the voltage of the test voltage Vo' after calculating the preset voltage value and superimposing the voltage adjustment value. Similarly, after the control circuit 10 obtains the phase adjustment value, it can obtain a phase command corresponding to the phase of the test voltage Vo' after calculating the preset phase value and superimposing the phase adjustment value. In practice, the voltage command and the phase command can enable the power supply circuit 12 to generate the corresponding test voltage Vo'. In this embodiment, the test voltage Vo' is referred to as an analog output voltage, which is used to indicate that the test voltage Vo' is the voltage after the analog preset output voltage Vo passes through the resistor R and the inductor L.

[0035] To illustrate the method of simulating output impedance in this embodiment, please refer to Figures 1 to 3 . Figure 31 is a flow chart of the steps of a method for simulating output impedance according to an embodiment of the present application. As shown in the figure, in step S20, the control circuit 10 selectively provides a simulation command when performing a test (such as a flicker test) of the DUT, and the simulation command is used to simulate the voltage adjustment value and the phase adjustment value of the preset output voltage Vo through the test circuit 94. In step S22, the control circuit 10 calculates the voltage adjustment value and the preset voltage value to form a voltage command. In step S24, the control circuit 10 calculates the phase adjustment value and the preset phase value to form a phase command. In step S26, the power supply circuit 12 in the AC power supply 1 generates a simulated output voltage according to the voltage command and the phase command.

[0036] In summary, the AC power supply with programmable output impedance and the method for simulating output impedance proposed in the present application calculate the voltage difference of the preset output current flowing through the resistor and inductor in the test circuit by the control circuit, and the power supply circuit uses the voltage difference to adjust the preset output voltage, so that the output voltage of the power supply circuit after adjustment is equivalent to the voltage after the external test circuit is connected. The AC power supply with programmable output impedance and the method for simulating output impedance of the present application do not require hardware replacement, and can simulate various external resistors or inductors to facilitate users to perform various test items.

[0037] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present application, and are not intended to limit the implementation methods of the technology of the present application in any form. Any technical personnel in this field may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present application, but they should still be regarded as technologies or embodiments that are essentially the same as the present application.

Claims

1. A method for simulating output impedance, for an AC power supply, the AC power supply comprising a control circuit and a power supply circuit, characterized in that: The method comprises: The control circuit selectively provides a simulation command, wherein the simulation command is associated with a voltage adjustment value and a phase adjustment value of a test circuit; The control circuit calculates the voltage adjustment value and a preset voltage value to form a voltage command; The control circuit calculates the phase adjustment value and a preset phase value to form a phase command; and The power supply circuit generates an analog output voltage according to the voltage command and the phase command; The preset voltage value and the preset phase value are associated with a preset output voltage provided by the power supply circuit, and the simulated output voltage simulates the voltage of the preset output voltage provided by the power supply circuit after passing through the test circuit.

2. The method for simulating output impedance according to claim 1, characterized in that: The test circuit is composed of at least a resistor and an inductor connected in series, and the simulated output voltage is used to simulate the voltage of the preset output voltage passing through the resistor and the inductor connected in series.

3. The method for simulating output impedance according to claim 2, characterized in that: The voltage adjustment value simulates the cross-voltage associated with the resistor and the cross-voltage associated with the inductor, and the phase adjustment value simulates the phase shift caused by the inductor.

4. The method for simulating output impedance according to claim 3, characterized in that: The voltage across the resistor is the product of a measured value of an output current provided by the power supply circuit and the resistance value of the resistor, and the voltage across the inductor is the product of the measured value of the output current and the impedance value of the inductor.

5. The method for simulating output impedance according to claim 3, characterized in that: The analog output voltage is used for a flicker test of an object under test.

6. An AC power supply with programmable output impedance, characterized in that: The AC power supply comprises: a control circuit selectively providing a simulation command, the simulation command being associated with a voltage adjustment value and a phase adjustment value of a test circuit, the control circuit calculating the voltage adjustment value and a preset voltage value to form a voltage command, the control circuit calculating the phase adjustment value and a preset phase value to form a phase command; and a power supply circuit, generating an analog output voltage according to the voltage command and the phase command; The preset voltage value and the preset phase value are associated with a preset output voltage provided by the power supply circuit, and the simulated output voltage simulates the voltage of the preset output voltage provided by the power supply circuit after passing through the test circuit.

7. The AC power supply with programmable output impedance according to claim 6, characterized in that: The test circuit is composed of at least a resistor and an inductor connected in series, and the simulated output voltage is used to simulate the voltage of the preset output voltage passing through the resistor and the inductor connected in series.

8. The AC power supply with programmable output impedance according to claim 7, characterized in that: The voltage adjustment value simulates the cross-voltage associated with the resistor and the cross-voltage associated with the inductor, and the phase adjustment value simulates the phase shift caused by the inductor.

9. The AC power supply with programmable output impedance according to claim 8, characterized in that: The voltage across the resistor is the product of a measured value of an output current provided by the power supply circuit and the resistance value of the resistor, and the voltage across the inductor is the product of the measured value of the output current and the impedance value of the inductor.

10. The AC power supply with programmable output impedance according to claim 8, characterized in that: The analog output voltage is used for a flicker test of an object under test.

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